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Biomedical subjects

Giancesare Guidi

Publications and source records attributed to Giancesare Guidi.

12 recordsLinked to original sources

Lipoprotein[a] and the lipid profile in patients with systemic sclerosis.

BACKGROUND: Systemic sclerosis (SSc) is an autoimmune disorder of the connective tissue characterized by widespread vascular lesions and fibrosis, associated with endothelial dysfunction, that might finally promote occlusive vascular complications. Little is known so far on the lipid profile of these patients. METHODS: To investigate the potential contribution of lipid abnormalities in genesis and progression of vascular occlusive complications, an extensive lipid profile, including total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglycerides, total cholesterol to HDL-C ratio, the atherogenic index of plasma, lipoprotein[a] (Lp[a]) and high-sensitive C Reactive Protein (Hs-CRP), was assessed in 31 consecutive female SSc patients and 33 matched healthy controls. RESULTS: When compared to healthy matched controls, SSc patients displayed statistically significant differences in median and 25-75th percentile distribution of Lp[a] (110 mg/l, 51-389 mg/l vs. 79 mg/l, 29-149 mg/l; P =0.005) and in the mean concentration of Hs-CRP (4.49 +/- 5.06 mg/l vs. 1.36 +/- 1.19 mg/l; P =0.001), but not in the other lipid parameters. When compared to the current NCEP or AHA/ACC goals, the values distributions and the relative percentage of patients with undesirable or abnormal vales were statistically different for Lp[a] (29% versus 3%) and Hs-CRP (42% vs. 12%) (both P <0.001). CONCLUSIONS: If further studies will strengthen these preliminary findings, owing to the growing evidence that Lp[a] might act in synergy with other defined prothrombotic conditions in the pathogenesis of a variety of vascular disorders, we hypothesize that Lp[a] measurement might be useful in SSc to identify and eventually treat subsets of patients more predisposed to develop thrombotic complications.

C-Reactive Protein↗

Comparison of serum creatinine, uric acid, albumin and glucose in male professional endurance athletes compared with healthy controls.

Owing to considerable physical, endocrinological and metabolic adaptations, the analysis of biochemical data in elite and top-class athletes requires caution. With the aim to identify metabolic and biochemical adaptations to particular lifestyle conditions, such as regular and strenuous physical exercise, we measured the concentration of serum albumin, creatinine, uric acid and glucose in 80 male professional cyclists, 37 male members of the Italian national cross-country ski team and 60 male healthy sedentary controls at rest. At variance with earlier investigations, endurance athletes showed significantly decreased concentrations of serum creatinine (controls: 83.1+/-11.0 micromol/l; skiers: 78.0+/-8.4 micromol/l; p<0.05; cyclists: 73.8+/-10.4 micromol/l; p<0.01), uric acid (controls: 362+/-69 micromol/l; skiers: 331 +/-70 micromol/l; p<0.05; cyclists: 312+/-61 micromol/l; p<0.01) and glucose (controls: 5.35+/-0.54 mmol/l; skiers: 4.94+/-0.41 mmol/l; p<0.01; cyclists: 4.94+/-0.42 mmol/l; p<0.01). The concentration of serum albumin was also decreased in athletes, but the difference did not reach statistical significance (controls: 4.76+/-0.26 g/l; skiers: 4.71+/-0.22 g/l; p=0.384; cyclists: 4.68+/-0.22 g/l; p=0.393). Results of the present investigation demonstrate that values of laboratory testing lying outside conventional reference limits calculated on sedentary populations might express physiological adaptations to regular and demanding physical aerobic activity, emphasizing the need for the estimation of reliable reference limits in elite and professional athletes, to avoid equivocal interpretation of results within clinical and anti-doping contests.

Adaptation, Physiological↗

Lipoprotein(a): an emerging cardiovascular risk factor.

Lipoprotein(a) is a cholesterol-enriched lipoprotein, consisting of a covalent linkage joining the unique and highly polymorphic apolipoprotein(a) to apolipoprotein B100, the main protein moiety of low-density lipoproteins. Although the concentration of lipoprotein(a) in humans is mostly genetically determined, acquired disorders might influence synthesis and catabolism of the particle. Raised concentration of lipoprotein(a) has been acknowledged as a leading inherited risk factor for both premature and advanced atherosclerosis at different vascular sites. The strong structural homologies with plasminogen and low-density lipoproteins suggest that lipoprotein(a) might represent the ideal bridge between the fields of atherosclerosis and thrombosis in the pathogenesis of vascular occlusive disorders. Unfortunately, the exact mechanisms by which lipoprotein(a) promotes, accelerates, and complicates atherosclerosis are only partially understood. In some clinical settings, such as in patients at exceptionally low risk for cardiovascular disease, the potential regenerative and antineoplastic properties of lipoprotein(a) might paradoxically counterbalance its athero-thrombogenicity, as attested by the compatibility between raised plasma lipoprotein(a) levels and longevity.

Arteriosclerosis↗

HDL3-related decreased serum paraoxonase (PON) activity in uremic patients: comparison with the PON1 allele polymorphism.

BACKGROUND: Patients with chronic renal failure on maintenance haemodialysis (HD) are at high risk of atherothrombotic events; an enhanced oxidant stress might have a major role. The decrease of human paraoxonase (PON1), an anti-oxidant high-density lipoprotein (HDL)-linked enzyme, is a possible mechanism for developing cardiovascular disease. To ascertain the causes of low PON1 in such patients, we investigated the contribution of both PON1 gene polymorphism and individual pattern of HDL. METHODS: On 74 HD patients (47 M and 27 F) and on 92 healthy individuals (HS, 48 M and 44 F), we studied PON1 activity, PON1 genotype (55 and 192 PON1 allelic polymorphisms) and the lipid profile, including the HDL subfractions. RESULTS: We observed in HD patients the following significant differences: (1) decreased median PON1 activity (73.5 vs. 110 U/l); (2) decreased mean HDL concentration (1.05 +/- 0.18 vs. 1.55 +/- 0.41 mmol/l); (3) decreased mean HDL3 concentration (0.79 +/- 0.21 vs. 1.28 +/- 0.24 mmol/l). Total HDL retained about 70% of serum activity, almost completely carried (95%) by the HDL3. Finally, PON1 activity remained significantly low in HD vs. HS after matching for the allelic polymorphism. CONCLUSIONS: The reduction of the HDL3, not the genetic PON1 polymorphism, seems the most important determinant of PON1 activity reduction in HD.

Adult↗

[Prevention of doping in sports: epidemiological issues and ethical implications].

Owing to a widespread diffusion, the consumption of banned and potentially harmful substances in sports has become a problem for the public health. Current estimations of the prevalence of doping in sports are rather uncertain, as most investigative tools do not reflect an absolute statistical power. However, the emerging scenario reflects a concerning underestimation by Structures and Institutions that should establish definitive rules and set reliable controls. Owing to restricted resources, prevention and fight against doping must be supported by meditated and rational strategies, with the aim to identify suitable contests and accurate procedures, considering carefully ethical issues that may arise from the positivity of the athletes to antidoping controls.

Doping in Sports↗