Endothelium and hemorheology.

Hemorheological alterations which can be found in ischaemic vascular diseases are well known and widely studied; less clear is the relationship between these alterations and endothelial function. Our studies showed that modifications in endothelial function caused by physical stress are associated with a worsening in hemorheological parameters mainly in patients affected by ischaemic vascular diseases: major vascular alterations have been found in patients with very high levels of plasma markers endothelial dysfunction. The control of the basal tone of the vessels is given by the complex interaction between vasoconstrictor and vasodilator endothelial factors and when this equilibrium is broken we have the endothelial dysfunction. From a methodological point of view we can find an endothelial dysfunction index determining the various substances produced by the endothelium, but it is very difficult to have a value which clearly identifies the real state of the endothelial alteration. The function of the NO, which is one of the more powerful endogenous vasodilators and whose synthesis is catalysed by nitric oxide synthase (NOS), can be determined by the ratio between blood concentrations of citrulline and arginine (the co-product and the precursor of the way of NO synthesis), which represents the level of activity of the enzyme. A very affordable index of the endothelial dysfunction is the asymmetric dimethylarginine (ADMA), a powerful endogenous inhibitor of NOS; in fact several studies demonstrated a strong relationship between ischaemic vascular diseases and high levels of plasma ADMA. Evaluation of these parameters is measured by means of high performance liquid chromatography (HPLC): this technique provides very affordable results and allows to obtain evaluations of substances in very small concentrations, like ADMA.

Posterior knee pain: primary symptom of a small non-occlusive venous clot.

A healthy 9 year old girl presented with severe posterior knee pain and a small segmental non-occlusive popliteal venous thrombosis. The case is relevant for its unique presentation and symptoms. Lack of recanalisation persisted at one year follow up.

Haemorheological and endothelial-dependent alterations in heart failure after ACE inhibitor, calcium antagonist and beta blocker.

The aim of our study was to evaluate endothelium-dependent dilatation induced by an ACE-inhibitor, calcium antagonist and beta blocker in patients suffering from heart failure (NYHA class II and III). We studied 34 patients (19M, 15F, mean age 76.96+/-8.82) in pharmacological wash-out for at least one week, divided into 3 groups: Group A (15 patients, 9M and 6F) taking ramipril (5 mg/die); Group B (10 patients, 6M and 4F) taking amlodipine (10 mg/die), Group C: (9 patients, 4M and 5F) taking carvedilole (25 mg/die). The groups were homologous for NYHA class and instrumental echographic parameters (mean EF=22.5+/-6.7 and mean sAPP 38.4+/-8.7). At the beginning and after 3 weeks of therapy, we performed a clinical and instrumental assessment; we studied endothelial function by determination of L-arginine and L-citrulline (amino acids of the nitric oxide metabolic pathway), the L-citrulline/L-arginine ratio (an index of NOS activity) and VCAM-1 (endothelial dysfunction index); haemorheological parameters (blood viscosity, plasma fibrinogen and erythrocyte morphology); coagulative/fibrinolytic parameters (PT, aPTT, fibrinogen and PAI-1). The results show that L-citrulline and L-arginine increase, while VCAM-1 decreases. The L-citrulline/L-arginine ratio increases in a statistically significant way. This trend is maintained in each group. These results demonstrate that the drugs used induce an improvement of endothelium-dependent dilatation. In addition, there is progressive haemorheological and fibrinolytic improvement, with a reduction of PAI-1 and blood viscosity.

Spontaneous echo-contrast as an in vivo indicator of rheological imbalance in dilatative cardiomyopathy.

The aim of this study was to evaluate coagulative and hemorheologic assessment in patients with dilatative cardiomyopathy with or without spontaneous echo contrast (SEC). We studied 45 patients, 35 males and 10 females (mean age 72.1 +/- 9.2). We measured whole blood viscosity, plasmatic fibrinogen, prothrombin time (PT), activated partial thromboplastin time (aPTT), D-dimer and red cell morphology with Zipursky-Forconi method. Transthoracic and transesophageal echocardiography was performed in all patients to evaluate the presence of SEC in left atrium. We divided all the patients into two groups: the 1st group of 20 patients with SEC and Atrial Fibrillation (AF) in 80% of cases, and the 2nd group of 25 patients without SEC and AF in 31%. Our results show that in patients with SEC there is a statistically significant increase of whole blood viscosity and plasma fibrinogen in comparison with patients without SEC. Red cell morphology in all patients demonstrates a reversed EMI. D-Dimer, was out of the normal range in about 1/3 of the patients in both groups. An analysis of our results points out that in patients with SEC and AF, with a major risk factor for cardioembolic stroke, we have alterations of hemorheologic assessment with an increase of whole blood viscosity and fibrinogen that seems to be caused by an increase of red cells aggregability favoured by fibrinogen. Our conclusions are that SEC in patients with dilatative cardiomyopathy and AF is an important in vivo indicator of hemorheologic imbalance and an important marker for cardioembolic risk stroke evaluation.

Blood viscosity and red cell morphology in subjects suffering from cirrhosis before and after treatment with S-adenosyl-L-methionine (SAM).

Alterations of fluidity of the hepatocytic membrane and of the transport related systems are the basis of the cholesteatic syndrome and favour the tissue accumulation of cytotoxic metabolites. S-Adenosyl-L-Methionine (SAM) is a natural molecule which acts as a giver of methylic groups and as an enzymatic activator in several enzymatic actions of transmethylase and of transulphuration and plays a key role in biochemical processes of hepatic cell. The aim of our study was to evaluate the effects of SAM on the restoration of the membrane fluidity and on the hepatic function in general. In studying the fluidity of the cell membrane we evaluated some hemorheological parameters (total blood viscosity and red cell morphology). Fluidity of the red cell membrane is one of the most important elements of red cell rheology. We studied 15 patients (Group A) suffering from micro- and macro-nodular cirrhosis verified through hepatic biopsy, with alcoholic or post-viral causes. We evaluated the values of: blood viscosity (with a cone-plate rheometer by Carri-med), haematocrit, plasma fibrinogen and the erythrocytic morphology at the optical microscope with the Zipursky-Forconi method before and after 7 days of therapy with SAM i.v.. Data were compared with those of a similar group (Group B) treated with traditional therapy only (hyposodic and hypoprotein diet supplemented with multivitamin preparations, vitamin K in particular, if necessary, and potassium sparing diuretics). We also measured biliary salts, alkaline phosphatase, transaminase and gamma-GT. In the first group we observed a statistically significant reduction of blood viscosity, haematocrit didn't change significantly; biliary salts reduced in a statistically significant way. Evaluation of red cell morphology showed in all cases a pathological percentage (>15%) of echinocytes and knizocytes which reduced to a mean of 5% after SAM therapy. We observed no further modifications of the other hemorheological parameters. Results demonstrate that SAM has a positive action on the fluidity of the membrane, as indicated by the improvement of haemorheological parameters and by the significant decrease of biliary salts, indicating the presence of cholesteasis.

Haemorheological disturbances and possibility of their correction in cerebrovascular diseases.

The presence of a hemorheological disturbance must be considered in the pathophysiological and therapeutical approach to vascular diseases, including cerebral diseases. A reduction of blood fluidity, due either to increase of hematocrit (polycythemic hyperviscosity) or of fibrinogen concentration (plasmatic hyperviscosity) or of red cell rigidity (sclerocythemic hyperviscosity) is commonly considered a condition of high risk for acute or chronic brain ischemia. So many attempts have been made for improving blood fluidity with the purpose to prevent stroke and to delay cerebral deterioration in chronic condition. This paper will present a review of the literature on this subject and the personal experience of our research group with the use of hemodilution, plasmapheresis and pharmacological agents. In our opinion the possible correction of hyperviscosity is very helpful in the prevention of acute ischemic attacks and in the reduction of their incidence in chronic cerebral ischemia. During the acute phase of stroke, hemorheological disturbance is only a part of the complex hemodynamic situation: a primary blood hyperviscosity can favor the onset of the disease but, because of its secondary increase after stroke, a vicious circle might be set in motion resulting in a further reduction of blood supply to the brain. Considering this, attempts in improving blood fluidity during stroke could be made, but with the caution that is required in this complicated "circulatory storm".

Evaluation of hemorheological parameters and red cell morphology in hypertension.

The aim of our study was to evaluate hemorheological parameters in two groups of patients both suffering from essential hypertension compared with an homologous group of subjects not suffering from hypertension; the 1st group was composed of 16 patients (8 females and 8 males, mean age 65.6 +/- 16.5) suffering from essential hypertension; the 2nd one of 26 patients (8 females and 18 males, mean age 74.3 +/- 11.7) suffering from essential hypertension and cerebral or cardiac ischemia in a chronic phase. The group of controls was composed of 20 subjects (mean age 50.5 +/- 11.5). In all these subjects we evaluated: blood viscosity, hematocrit, plasmatic fibrinogen, red cell morphology according to Zipursky-Forconi method and blood pressure. Our results show that blood viscosity and fibrinogen were statistically increased relative to controls. Comparison between these groups leads us to observe that blood viscosity and fibrinogen are slightly higher in the first group in a statistically significant way (7.5 +/- 1.1 cPs 10 s(-1) 1st group, 7.9 +/- 1.05 cPs 10 s(-1) 2nd group; 362.2 +/- 167.3 mg% 1st group, 384.6 +/- 106.9 mg% 2nd group). Blood pressure was higher in the second group. The study of red cell morphology in all the patients showed a prevalence in the percentage of discocytes, cells which have less deformability compared to bowls. The study demonstrated EMI (Erythrocyte Morphology Index) decreased in a statistically significant way compared to controls (0.70 +/- 0.03 1st group; 0.65 +/- 0.02 2nd group; 1.2 +/- 0.09 control group). In subjects suffering from essential hypertension with end-organ damage EMI further decreases. So we observed that hypertension is also delineated by the increase in the discocytes percentage which results in reduction of the red cell deformability. In conclusion, when hypertension causes end-organ damage, the hemorheological alterations, which implicate a worsening in microcirculation, are more evident.

Evaluation of erythrocyte morphology as deformability index in patients suffering from vascular diseases, with or without diabetes mellitus: correlation with blood viscosity and intra-erythrocytic calcium.

The aim of our study was to evaluate the erythrocytic morphology in vascular patients, with or without diabetes, showing cell alterations correlated to blood viscosity and intra-erythrocytic calcium. We studied 108 subjects: 20 normal subjects, 58 vascular patients (25 suffering from CHD, 19 from CVD, 14 from POAD) and 30 non-insulin-dependent diabetes patients with vascular disease in metabolic compensation (13 CHD, 9 CVD, 8 POAD). Erythrocytic morphology, blood viscosity and intra-erythrocytic calcium were evaluated. Our results show that bowls, the most deformable red cells, decreased significantly in vascular patients and in POAD diabetics, while the discocytes, having a stiffer form, greatly increased in subjects suffering from ischemic disease and in POAD diabetics. The altered red cells (echinocytes and knizocytes) reached a statistical significance in CVD and POAD diabetics. Comparing the percentage of discocytes to intraerythrocytic calcium content in vasculopathic subjects, we obtained a significant correlation. No evidence of a relationship between discocytes and blood viscosity was found, even if blood viscosity significantly increased in patients affected by ischemic disease. These results suggest that ischemia decreases the deformability of red cells which is supported by the study of red cells morphology, by the erythrocytic morphology index (EMI), which becomes < 1, and by the evaluation of cytosolic calcium content.

Variations of erythrocyte morphology in different pathologies.

In our study we evaluated erythrocytic morphology in different pathologies which can modify flowing red cells. We followed the methodology proposed by Zipursky which allows a three-dimensional evaluation of the red cell and a classification according to the shapes observed through the optical microscope. We studied 150 subjects: 20 normal subjects, 58 patients suffering from vascular diseases, 40 affected by diabetes (type II) (10 without and 30 with vascular diseases), 22 patients with liver disease, 5 patients with monoclonal gammopathies and 5 dehydrated patients. Results show that in normal subjects bowls, which is the shape of the most deformable red cells, are more (55%) than discocytes (44%); the altered forms are only 1%. In vascular patients we noted a statistically significant increase of discocytes (60%). There are no significant differences between subjects affected by diabetes without vascular disease and normal subjects. In diabetics with vascular diseases there are more discocytes (57%) and some altered forms (3%). In patients suffering from chronic hepatitis a great increase (13%) in echinocytes and knizocytes was noticed, which suggests an alteration in the fluidity of the membrane. Our observations testify the importance of this simple methodology in focusing the morphological alterations which can be accounted for both by pathologies of the red cells and by changes in their metabolism.

[An epidemiological study on blood viscosity and intraerythrocytic calcium in a group of high-school students selected according to their family histories]. / Indagine epidemiologica sulla viscosità ematica e sul calcio intraeritrocitario in un gruppo di studenti liceali selezionati in base all'anamnesi familiare.

An epidemiological study was performed in a group of secondary school students selected according to their family history to assess whether changes exist in blood viscosity and intraerythrocytic calcium levels in young healthy subjects with positive family histories of arterial hypertension or cerebral and cardiac ischemic vasculopathies, compared to a control group with a negative family history of these disorders. A population of 130 secondary school students without any pathologies were subdivided into 4 groups: 1) with a positive family history of ischemic cardiopathy (ICP); with a positive family history of cerebral ictus; 3) with a family history of arterial hypertension; 4) a negative family history of these diseases. Total blood viscosity, hematocrit, plasma fibrinogen and intraerythrocytic calcium was evaluated in all groups. The results show that these parameters were within the normal range, as was to be expected in healthy subjects. Blood viscosity was also normal in all groups; intraerythrocytic calcium levels were slightly higher in groups with histories of cardiovascular disease and in particular there was an increased percentage of cases with values above the threshold level. Higher fibrinogen levels were also recorded, but always within the normal range, in the group with a positive history of ICP. The epidemiological study is important to assess whether a family pattern of cardiovascular disease can also influence such independent risk parameters as blood viscosity and intraerythrocyte calcium, owing to the possible greater frequency of development of cardiovascular disease.

[Plasma Lp(a) levels: a comparison between diabetic and nondiabetic patients with the nephrotic syndrome and control subjects]. / Livelli plasmatici di Lp(a): confronto tra pazienti diabetici, non diabetici, affetti da sindrome nefrosica e soggetti di controllo.

The aim of this study was to evaluate Lp(a), total, HDL and LDL cholesterol, triglycerides, Apo A and Apo B100 plasmatic concentrations in patients affected by nephrotic syndrome that is known able to increase the ratio of the risk of cerebral and cardiovascular events, in comparison with a group of healthy patients homologous for sex and age. In the group of patients with nephrotic syndrome we have compared the variables between diabetic mellitus type I patients and non diabetic patients. All the variables, in exception of HDL cholesterol, were significantly increased in the group of patients with nephrotic syndrome compared with the control group. HDL-cholesterol concentration was significantly higher in controls than in nephrotic patients. Diabetic and nephrotic patients showed increased levels of Lp(a) concentration than non diabetic patients and the difference was statistically confirmed. These data suggest that Lp(a) acts really like a risk factor for atherosclerotic disease, being elevated in patients characterized for increased risk for cerebral and cardiovascular events because of the presence of nephrotic syndrome. Moreover we can suppose that elevated plasmatic Lp(a) levels in nephrotic patients could be linked to increased synthesis of proteins in the liver as physiological reaction to severe proteinuria.

[Lp(a) and lipid order in a group of secondary school students selected according to their family anamnesis]. / Lp(a) e quadro lipidico in un gruppo di studenti liceali selezionati in base all'anamnesi familiare.

In this study we evaluated the several risk-factors, Lp(a) and lipids order, related to the family history for ischaemic cardiovascular disease (CHD) atherosclerotic cerebrovasculopathy and arterious hypertension, in a healthy adolescent group, to stress possible early and significant alteration of the lipids order and Lp(a); we also considered which of these parameters may be considered the risk factor most closely related to family history. We studies 130 healty high school students, mean age 16.5 +/- 5.5 years, selected in four groups related to the family history: the first one composed of 34 subjects with positive family history for CHD; the second one of 32 subjects with positive family history for cerebral infarction (CI); the third by 32 subjects with family history for arterial hypertension and the last group by 30 control subjects. Mean value of all variables considered was in the normality range. Lp(a) resulted in the normality range with the exception of the group with positive family history for CHD. Also the traditional risk factors (Total-Col., LDL/Col. and Triglycerides) were increased in this group. Besides the differences between the mean of Lp(a) and Total/Col. in the group with positive family history for CHD and in the control group were statistically significant. The results showed that Lp(a), even if it cannot replace the family history in the screening of coronary atherosclerotic disease, might be considered a risk marker of early atherosclerotic disease.

Comparison of total-body measurements by dual-energy X-ray absorptiometry and dual-photon absorptiometry.

Both dual-photon absorptiometry (DPA) using 153Gd and dual-energy x-ray absorptiometry (DEXA) can be used for measurement of bone mineral content (BMC) and bone mineral density (BMD) of the total skeleton and its seven major regions. The short-term precision (coefficient of variation, CV) of DEXA for total-body BMD using the medium (20 minute) and fast (10 minute) speeds was 0.34 and 0.68% in 5 normal subjects; the corresponding CV in 5 osteoporotic females were 0.70 and 1.04%. The CV for BMD using DPA was 0.82% in 8 normal subjects and 0.70% in 12 osteoporotic patients. The CV for regional BMD using DPA was similar to fast-speed DEXA, without significant differences (p NS); precision with medium-speed DEXA was superior to DPA, and the differences were statistically significant (p less than 0.05) for head, spine, trunk, ribs, and pelvis. Total-body measurements using both DPA and DEXA were done on 99 subjects (84 females and 15 males). Significant correlations (r = 0.98; p less than 0.001) were found between DEXA and DPA measurements of both BMC and BMD. There were also significant correlations (r = 0.94-0.98; p less than 0.001) between DEXA and DPA measurements of anatomic regions (head, trunk, spine, pelvis, ribs, arms, and legs). DPA and DEXA results for BMD of total skeleton, ribs, pelvis, and legs were similar (p NS), and statistically significant differences were found in head, spine, and arm measurements (p less than 0.01, p less than 0.01, and p less than 0.05, respectively); regression equations allowed adjustment of DEXA values in patients already measured with the earlier DPA method.

Long-term treatment with calcitriol in postmenopausal osteoporosis.

In order to assess the long-term effects of calcitriol treatment in postmenopausal osteoporotic patients, 1.0 micrograms/d of calcitriol was administered in two divided doses for 1 to 8 years to 270 women with symptomatic, histologically proven postmenopausal osteoporosis. No calcium supplementation was given. Clinically, the treatment resulted in substantial relief from pain, with improvement of ambulancy. Intestinal calcium absorption, which was lower than normal at baseline, increased significantly and remained higher than the baseline value as long as calcitriol was administered. Urinary calcium absorption also increased, but hypercalcemia occurred, exceptionally and transiently, in only a few patients. Urinary hydroxyproline excretion did not increase, indicating that hypercalciuria was not of resorptive origin. Total-body density, determined by dual-photon total-body absorptiometry in 56 patients, showed an increase after 18 to 24 months of therapy in most cases. The occurrence of nontraumatic, clinically relevant fractures decreased noticeably as compared with the period preceding calcitriol treatment. No change occurred in renal function, and no renal stones developed. Calcitriol was an effective and safe treatment of postmenopausal osteoporosis.

Total body and regional bone mineral analysis by dual-photon absorptiometry in Paget's disease of bone.

Total body density (TBD), total body bone mineral (TBBM) and bone mineral content of major anatomical skeletal areas were measured in 66 patients with Paget's disease of bone (54 polyostotic; 12 monostotic; 38 males; 28 females; 38-88 years), by dual-photon absorptiometry (153 Gd). TBD was elevated in 23 males and three females with Paget's disease; a statistically significant correlation was found between elevated values of TBD and a widespread extent of the disease. The mean value of TBBM was higher in pagetic males, while in pagetic females it was similar to normal subjects. The separate analysis of anatomical areas allowed us to appreciate increased values of bone mineral content in head, trunk, spine, pelvis, arms. Moreover in 28 patients with easily detectable pagetic lesions of long bones, 38 specific regions of interest (ROI) were evaluated: pagetic areas showed significantly higher values of bone density and bone mineral content in comparison with contralateral uninvolved areas.

Diagnostic approach to osteoporosis and spondyloarthrosis in post-menopausal women by total body dual-photon absorptiometry.

Dual-photon absorptiometry of total body (153 Gd with photopeaks at 44 and 100 keV) enables bone mineral content of the entire skeleton and its major anatomical areas to be quantitated. Total body bone mineral (TBBM), total body density (TBD), bone mineral content and bone density of spine and lumbar-spine were measured in 97 women with post-menopausal osteoporosis, 33 females with spondyloarthrosis and in 19 females with spondyloarthrosis associated with osteoporosis. Seventy-nine females of similar age made up the normal control group. TBBM and TBD proved to be significantly lower in post-menopausal osteoporotic women compared to age-matched normal females: bone loss was particularly evident in spine measurements. In spondyloarthrosis patients TBBM and TBD fell within the normal range and both spine bone density and spine bone mineral did not differ from normals. TBD, TBBM, spine density and spine mineral in females with disuse osteoporosis associated with spondyloarthrosis were significantly lower in comparison with normals and higher with respect to post-menopausal osteoporotic women. Total body absorptiometry represents a valuable method in the differential diagnosis of post-menopausal osteoporosis, spondyloarthrosis and the disuse osteoporosis associated with spondyloarthrosis.