Association between fibrinogen plasma levels and platelet counts in an outpatient population and in patients with coronary heart disease.

Although numerous studies concern fibrinogen (FBG) associations, the relationship between platelet (PLT) count and FBG plasma levels has yet to be completely investigated. The present study concerns the association between FBG plasma levels and PLT count in 5891 patients (2831 men and 3060 women) attending our outpatients' laboratory. Of these, a subgroup of 4116 patients (1899 men and 2217 women) with normal values of the parameters investigated was selected. A group of 170 patients with coronary heart disease was also included. The parameters studied were FBG, PLT count, leukocyte count and age. Our results showed that, in the outpatient population, FBG was significantly correlated with the PLT count (P < 0.000001) and, as previously reported, with the leukocyte count and age. In the patients with coronary heart disease, there was a significant correlation between FBG and PLT count (P < 0.000001), to be considered very significant considering the limited number of patients, whereas no correlation with age or leukocyte count was found. The role of interleukin-6, both in FBG and PLT production, is well known and may explain the correlation between these two parameters. The association of FBG and PLT count has yet to be fully investigated in epidemiological studies, even though they play an important role as two of the major contributors to the pathogenesis and evolution of cardiovascular diseases.

Antithrombin III metabolism in the pulmonary vessel endothelium.

In 85 patients undergoing aorto-coronary bypass for atherosclerotic coronary disease, we measured the antithrombin III activity levels and the thrombin-antithrombin III complex concentrations in blood from the pulmonary and the radial arteries, taken before the aorto-coronary bypass procedure, with the aim of investigating the role of the pulmonary endothelium in the metabolism of the inhibitor. Results showed significantly lower mean antithrombin III activity levels, expressed as a percentage of normal plasma, in blood from the radial artery with respect to levels from the pulmonary artery (0.78 +/- 0.12 versus 0.80 +/- 0.12, P<0.0001), while no significant difference was found in thrombin-antithrombin III complex concentrations. The results seem to show that the pulmonary endothelium contributes to the antithrombin III metabolism with a 0.023 breakdown rate, corresponding to about a 0.1 fraction of the reported 0.22-0.25 total body catabolic rate, as well as the pulmonary endothelial surface (50-70 m2) corresponding to about a 0.1 fraction of the peripheral vessels' endothelial surface (500-700 m2). The data support the hypothesis of a main endothelial catabolism of antithrombin III.

Bisphosphonate treatment in ochronotic osteoporotic patients.

In ochronotic patients, abnormalities in bone metabolism leading to increased bone loss have been reported. Therefore, we attempted antiresorptive therapy to (almost) partially reverse bone loss in four out of five osteopenic or osteoporotic ochronotic patients, two men and two women, aged 56-82 years. Each patient was treated with a 70-mg tablet of alendronate weekly and 1,000 mg/day of elemental calcium, such as gluconolactate or carbonate, throughout 24 months. Before starting therapy, and after 1 and 2 years of treatment, the bone mineral density (BMD) at the femoral subregions and at the lumbar spine was measured (in grams per square centimeter and as a T score) by dual energy X-ray absorptiometry. A 50-year-old osteopenic ochronotic man refusing the treatment underwent the same checks. The BMD was measured in all patients on the same densitometer by the same operator. The results showed a progressive decrease of the femoral subregion BMD measurements both in the bisphosphonate-treated patients and in the untreated patient. In particular, the percentage differences with respect to the basal values of the total femur BMD measurements ranged from -0.52 to -6.72% in the first year and from -5.29 to -9.05% in the second year. The lumbar spine BMD measurements provided spuriously overestimated results. Moreover, two treated patients and the untreated patient experienced fragility fractures of the femur. The study showed that osteoporosis and fragility fractures are prominent manifestations in the natural history of ochronosis. Matrix microdamage, osteocyte viability, and collagen cross-linking impairment, due to homogentisic acid and to its polymer, might be the processes involved. For this reason, the bisphosphonate therapy was ineffective.

Fibrinogen metabolism in the lungs.

The aim of this study was to evaluate the role of the pulmonary vessel endothelium in the metabolism of fibrinogen (FBG), by measuring the FBG, D-dimer, and fibrin(ogen) degradation product levels in the blood from pulmonary and radial arteries from 99 patients undergoing aortocoronary bypass. For comparison, protein C, protein S, and factor VII, were also measured. The results showed, with respect to the pulmonary arterial blood levels, significantly lower FBG levels (3.72 +/- 0.83 vs 3.66 +/- 0.81 g/L; P < .001) and higher fibrin(ogen) degradation product levels (7.36 +/- 1.53 vs 8.15 +/- 1.59 mg/L; P < .000 01) in the radial arterial blood. No difference was found for d -dimer, protein C, protein S, and factor VII. The study demonstrated that the pulmonary capillary endothelium contributes to the FBG catabolism for about a 0.02 fractional rate and support the view of an endothelial FBG catabolic pathway as the main catabolic pathway, owing to the fact that the pulmonary endothelial surface is about a 0.1 fraction of the peripheral vessel endothelial surface.

Age related prolactin secretion in men after fentanyl anaesthesia.

The aim of this study was to investigate the role of age in the hormonal response to opiate anaesthetic fentanyl. In 90 patients undergoing aortocoronary bypass, 59.6 +/- 9.2 years mean age, 35-81 age range, prolactin (PRL), thyroid stimulating hormone (TSH), follicle stimulating hormone (FSH), luteinizing hormone (LH), human growth hormone (HGH), insulin-like growth factor I (IGF I), glucagon and insulin were measured in venous blood samples drawn from fasting patients immediately before, at 8 h in the morning, and 60 min after the induction of anaesthesia with 30 microg/kg intravenous fentanyl bolus, 30 min after a second 7 microg/kg fentanyl bolus. Results showed a higher 60 min PRL peak in older, >65 years, in respect to younger, < or =50 years, patients (57.6 +/- 23.3 vs. 40.6 +/- 13.8 microg/l, P<0.005), with a significant upward trend with age across the entire age span (r=0.32; P<0.002), while no difference by age was found for the basal concentrations. No differences were found between the respective basal and 60 min concentrations for the other hormones investigated. As expected, differences by age were found for FSH, higher in >65 and in 51-65-year-olds than in younger patients (for the basal values, respectively, P<0.02 and P<0.05); IGF I was lower in >65 in respect to < or =50 (P<0.02) and to 51-65-year-old patients (P<0.05), with a significant negative correlation with age (r=-0.33; P<0.005). The study shows an age related increase of PRL concentrations after fentanyl administration. It may be due to the reduction of the hypothalamic dopaminergic tone with aging. IGF I levels have been confirmed to be inversely correlated with age.