Gray matter volume in relation to cardio-vascular stiffness.

BACKGROUND: Hemodynamic disturbances are associated with aging as well as the chronic process of left ventricular and arterial stiffening. This process can influence gray matter volume and thereby contribute to brain atrophy. We performed a comprehensive assessment of left ventricular and arterial function as well as central hemodynamics. These data were correlated with gray matter volume (GMV) as evaluated by magnetic resonance imaging (MRI). METHODS: GMV and aortic stiffness were estimated using MRI. Left ventricular end-systolic elastance or stiffness (Ees), arterial elastance (Ea) and total arterial compliance (TAC) were determined by echocardiography. Central hemodynamics were assessed using pulse wave analysis. RESULTS: Seventy-five healthy subjects (42 women, 33 men, mean age of 58 years) were recruited. The clinical analyses showed that GMV correlates significantly and inversely with age (r=-0.37, P=0.001), end-systolic LV stiffness (r=-0.39, P=0.0009), augmentation pressure (r=-0.48, P<0.0001), arterial elastance (r=-0.27, P=0.02) and aortic stiffness (r=-0.23, P=0.04), as determined by aortic pulse wave velocity (aPWV). GMV correlated significantly with total arterial compliance (r=0.23, P=0.04). Stepwise forward multiple regression analysis revealed that 35% of variance (P<0.0001) in GMV is attributed to aPWV, Ees and AP. CONCLUSIONS: Left ventricular end-systolic stiffness, augmentation of central arterial pressure and aortic stiffness are associated independently and negatively with GMV. These associations suggested that brain atrophy is influenced by hemodynamic factors.

The influence of growth hormone (GH) therapy on cardiac performance in patients with childhood onset GH deficiency.

OBJECTIVE: There is accumulating evidence that growth hormone (GH) plays an important role in the maintenance of normal cardiac growth and function. Abnormalities in left ventricular diastolic function and impairment of systolic function have also been reported in patients with GHD. In this study, we investigated the effects of 12 months GH replacement therapy on cardiac functional indices measured by echocardiography, the ECG stress test and SPECT imaging. DESIGN: Sixteen patients with childhood onset GHD (age 42.3+/-13.1 years, 10 males) were investigated before, and after, 12 months of GH treatment at a dosage of 0.02 IU/kg/day (7 microg/kg/day). The GH administration resulted in serum IGF-I levels within the normal range in all the patients. The following investigations were performed initially and after 12 months: electrocardiography, systolic and diastolic blood pressure, heart rate measurement, a complete Doppler-echocardiographic examination, treadmill exercise test and Technetium-99m sestamibi single-photon emission computer tomography (SPECT) imaging at rest and after exercise. RESULTS: Echocardiography showed improvement in left ventricular systolic function after GH treatment. End-systolic volume fell from 29.9+/-12.4 to 24.4+/-6.9 ml (p<0.05) and the ejection fraction increased from 56.2+/-7.2% to 63.2+/-6,1% (p<0.01). Left ventricular diameter and wall thickness did not change after GH treatment, although systolic increase in interventricular septum thickness (IVS%) and systolic increase in posterior wall thickness (PWT%) increased significantly (IVS% 52.2+/-31.9% vs. 67.3+/-30.4% and PWT% 48.7+/-20.2% vs. 58.0+/-17.7%, p<0.01, p<0.01, respectively). Contractile function, measured at midwall level, improved as left ventricular midwall fractional shortening (MWS) increased (16.11+/-6.55 vs. 23.30+/-5.89 %, p<0.01) and stress-corrected MWS increased between the examinations performed before and after 12 months of GH treatment (90.97+/-36.66 vs. 133.10+/-32.84 %, p<0.01). Diastolic function did not change, as assessed by early diastolic flow (E), diastolic flow secondary to atrial contraction (A), or the E/A ratio. The LV-mass index did not change significantly after GH treatment (78.4+/-22.1 vs. 81.9+/-21.1g/m(2)). After 12 months of GH treatment the myocardial performance index (MPI) decreased significantly from 0.483+/-0.146 at baseline to 0.410+/-0.086 at the end of the study (p<0.05). There was a trend towards an increase in exercise duration and capacity after GH treatment but the differences did not reach levels of statistical significance. SPECT imaging basally and after 12 months showed normal myocardial perfusion at rest and after exercise in all the patients. In conclusion, GH replacement therapy in adults with GHD demonstrated the beneficial effects on cardiac functions.

Effects of magnetic resonance imaging on polymorphonuclear neutrophil adhesion.

BACKGROUND: Limited research has been performed concerning the effects of MR imaging on the immune system. In this study the influence of MR imaging exposure on polymorphonuclear neutrophil (PMN) adhesion was evaluated. MATERIAL AND METHODS: In vivo and in vitro studies were performed in 10 patients undergoing an MR imaging procedure, PMN adhesion to a plastic surface, as well as the expression of adhesion molecules beta 2-integrins CD11b, CD18, and L-selectin on the surface of PMN were estimated. RESULTS: Exposure to MR imaging significantly increased adhesion of isolated PMNs to plastic surfaces. PMNs from blood samples obtained from patients undergoing MR imaging as well as from blood samples placed beside patients during MR imaging did not differ from controls in adhesion to plastic surfaces. Similarly, plasma from three tested samples did not change control PMN adhesion to plastic surface. Expression of beta 2-integrins (CD11, CD18) was significantly increased in samples left beside patients during MR imaging, while significantly decreased in samples obtained from patients after MR imaging exposure when compared to control samples. Expression of the surface adhesion molecule L-selectin on the surface of PMN decreased significantly in blood samples left beside patients during MR imaging. CONCLUSION: The results indicate that the PMN adhesion properties increase under the influence of MR imaging exposure. This phenomenon may be the result of direct stimulation of polymorphonuclear neutrophils by the exposure to MR imaging.

Hydrogen peroxide and superoxide anion production by polymorphonuclear neutrophils in patients with chronic periapical granuloma, before and after surgical treatment.

Chronic periapical granuloma represents a localized tissue injury with well established signs of systemic immunological reactions. The aim of the study was to investigate changes in superoxide anion and hydrogen peroxide production by polymorphonuclear neutrophils (PMN) in patients with chronic periapical granuloma before and after surgical treatment. The affected teeth were extracted from 20 patients with chronic periapical lesions. Blood samples were obtained at admission, before extraction and on day 14. PMNs were isolated from blood samples and superoxide anion (O2-) and hydrogen peroxide (H2O2) production were estimated without stimulation and after stimulation of the cells with opsonized zymosan. Similar procedures were performed with blood samples obtained from 20 healthy controls. Superoxide anions as well as hydrogen peroxide production by unstimulated cells obtained from patients before treatment were significantly higher in comparison with controls. Fourteen days after extraction O2- production by unstimulated cells was higher than the controls and significantly lower in comparison to PMNs obtained before treatment, while H2O2 production was not significantly higher when compared to controls and significantly lower in comparison with PMNs obtained before extraction. The results obtained strongly imply the termination of a generalized inflammatory response after elimination of local inflammation by tooth extraction.

Fibrinolytic therapy and n-acetylocysteine in the treatment of patients with acute myocardial infarction: its influence on authentic plasma hydroperoxide levels and polymorphonuclear neutrophil oxygen metabolism.

Recently it has been demonstrated that the administration of n-acetylocysteine (NAC), in combination with streptokinase, significantly diminished oxidative stress in patients with myocardial infarction. The aim of our study was to assess the influence of NAC treatment, as adjunct therapy in an evolving myocardial infarction, on the polymorphonuclear count, superoxide anion and hydrogen peroxide levels and nitric oxide production by PMNs and authentic plasma hydroperoxide (ROOH). Treatment of patients with NAC in addition to reperfusion therapy was accompanied by a significant decrease in the number of circulating polymorphonuclear neutrophils. However, the oxygen metabolism of PMNs was not affected by NAC administration. The concentration of authentic plasma hydroperoxide was significantly reduced by the administration of NAC which suggests diminished oxidative stress during acute myocardial infarction.

Plasma chemotactic activity during dipyridamole induced myocardial ischemia.

BACKGROUND: We have previously reported that transient myocardial ischemia induced during exercise or dipyridamole challenge leads to the release of increased amounts of hydrogen peroxide into circulating blood. It would indicate that the temporary functional changes within myocardial cells may constitute there a sterile inflammatory area. Therefore we decided to evaluate the chemotactic properties of plasma in patients undergoing dipyridamole provocative test, as a sign of released inflammatory mediators. The ischemia occurrence was evaluated with 99mTc-SestaMIBI followed by single photon emission computed tomography (SPECT). METHODS: Blood samples were obtained from the peripheral vein of 42 patients (18 men and 24 women, mean age 61 years). Plasma chemotactic activity was determined by the use of the Boyden chamber method: immediately before dipyridamole challenge (time 0), 7, and 30 min after drug infusion. The migration of control polymorphonuclear neutrophils towards evaluated plasma samples was estimated. RESULTS: Chemotaxis of control PMNs towards plasma isolated from patients without signs of myocardial ischemia 7 min after dipyridamole administration was significantly diminished in comparison with baseline values (p=0.003). Plasma obtained 7 min after dipyridamole infusion from patients manifesting signs of myocardial ischemia by SPECT attracted control PMNs significantly more intensively in comparison to plasma isolated at time 0 (p=0.0005). CONCLUSIONS: The obtained results indicate that transient myocardial ischemia induced by dipyridamole challenge leads to generation of chemotactic factors detectable in peripheral blood plasma.

The influence of electrical cardioversion on superoxide anions (O2-) production by polymorphonuclear neutrophils, hydrogen peroxide (H2O2) plasma level and malondialdehyde serum concentration.

We studied the influence of electrical cardioversion on unstimulated and stimulated superoxide anion production by polymorphonuclear neutrophils in 22 patients with atrial flutter or atrial fibrillation. We also estimated hydrogen peroxide plasma level, as well as malondialdehyde serum concentration, in these subjects. We noted an increase in spontaneous production of superoxide anions from 14.9 +/- 1.8 nmol/10(6) neutrophils per 20 min to 21.37 +/- 2.7 nmol/10(6) neutrophils per 20 min (P = 0.002) in neutrophils obtained after electrical cardioversion. Similarly, stimulated production of O2- also increased after electrical cardioversion (41.8 +/ 3.4 nmol/10(6) neutrophils per 20 min vs. 59.0 +/- 5.9 nmol/10(6) neutrophils per 20 min, P = 0.0027). Moreover, hydrogen peroxide plasma level increased significantly after electrical cardioversion (39.9 +/- 6.2 mumol/l vs. 53.4 +/- 7.6 mol/l, P = 0.003). Serum malondialdehyde concentration also increased after countershock (2.56 +/- 0.26 nmol/ml vs. 2.94 +/- 0.26 nmol/ml, P = 0.023). These results seem to indicate that electrical cardioversion may lead to polymorphonuclear neutrophils activation, increased H2O2 production and lipid peroxidation.

Effects of magnetic resonance imaging on polymorphonuclear neutrophil functions.

RATIONALE AND OBJECTIVES: Limited research has been performed on the effects of magnetic resonance (MR) imaging on the immune system. To our knowledge, there are no reported studies of MR imaging effects on the polymorphonuclear neutrophil (PMN) system. Therefore, we evaluated the influence of MR imaging exposure on PMNs. METHODS: In vivo and in vitro studies were performed on 36 patients undergoing MR imaging. The following were estimated in blood samples: leukocyte and PMN count, PMN phagocytosis and bactericidal capacity, percentage of cells with expression of surface receptor for the Fc fragment of immunoglobulin G (IgG), PMN superoxide, hydrogen peroxide production, and plasma lysozyme activity. Another sample of patients was used to eliminate temperature as an influence on changes in PMN functions. RESULTS: Both in vitro and in vivo MR imaging led to a decrease in PMNs and an increase in PMN phagocytosis, bactericidal capacity, hydrogen peroxide production, and percentage of cells with expression of surface receptor for Fc IgG. Superoxide anion production did not change significantly. Elevated temperature, stress, and anxiety were excluded as influences on our results. CONCLUSION: The PMN system is affected seriously by MR imaging.

Mortality and clinical course of patients with acute myocardial infarction treated with streptokinase and antioxidants: mannitol and ascorbic acid.

There is increasing evidence that free radical scavengers limit reperfusion injury in animal experiments. We randomly administered 250 ml 20% mannitol infusion and 10.0 g ascorbic acid infusion, potent free radical scavengers to 42 patients with acute myocardial infarction receiving streptokinase. A control group of 42 patients received only standard fibrinolytic therapy. We found that additional antioxidant treatment with ascorbic acid and mannitol decreased the number of some complications of acute myocardial infarction.

Estimation of hydrogen peroxide plasma levels in patients evaluated for coronary heart disease using dipyridamole infusion followed by SPECT.

BACKGROUND: Prolonged ischemia leads to myocardial infarction and increased formation of toxic oxygen radicals. These substances exert deleterious effects on myocardial cells, contributing to reperfusion injury and generation of arrhythmia. Little information is available, however, concerning the toxic oxygen species generated during transient ischemia. The purpose of our study was to estimate hydrogen peroxide plasma levels in patients subjected to short-lasting ischemia induced by a dipyridamole stress test used for the diagnosis of coronary artery disease. Evaluation of the performed test was carried out with 99mTc-SestaMIBI followed by single photon emission computed tomography (SPECT). METHODS: Blood was obtained from peripheral veins of 53 patients (37 men and 16 women, mean age 49 +/- 11 years). Plasma hydrogen peroxide levels were estimated by spectrophotometric methods: immediately before a dipyridamole challenge and after drug infusion. RESULTS: Hydrogen peroxide plasma levels in patients with a negative SPECT test were 23.5 +/- 3.0 mumol/l (mean +/- SEM) and 21.0 +/- 2.9 after the dipyridamole infusion (P = 0.474). Plasma concentrations of hydrogen peroxide in patients with a positive SPECT test were 30.5 +/- 4.6 and increased after dipyridamole challenge to 50.3 +/- 5.4 (P = 0.004). Further analysis revealed that the observed difference cannot be attributed to previous history of myocardial infarction. CONCLUSIONS: Even transient myocardial ischemia can generate toxic oxygen derivatives. Evaluation of plasma levels of hydrogen peroxide may be of clinical relevance in patients with suspected coronary artery disease.

Comparison of the influence of stress exercise test and transesophageal cardiac pacing on polymorphonuclear neutrophils functions.

Peripheral polymorphonuclear neutrophils (PMN) number, percent of PMN bearing IgG Fc receptors as well as PMN adherence were evaluated in 29 patients submitted to an exercise test. The peripheral PMN count significantly increased at the maximal work load. The increase in number of neutrophils bearing IgG Fc receptors was also noticed at that point, while PMN adherence to nylon wool columns did not change significantly. Nine subjects were additionally submitted to diagnostic transesophageal atrial pacing with a rate similar to maximal heart rate observed during the exercise test. It was revealed that atrial pacing in these patients had no influence on the peripheral PMN count, PMN adherence as well as number of neutrophils bearing IgG Fc receptors. We conclude, that granulocytosis observed during exercise can not be solely attributed to the increased heart rate and increased cardiac output but other mechanisms like muscle work play a significant role in this process.

[The effect of blood pressure changes during hemodialysis on left ventricular systolic function]. / Wplyw zmian cisnienia tetniczego w czasie hemodializy na czynnosc skurczowa lewej komory serca.

Echocardiographic study was performed in 31 uremic patients on maintenance hemodialysis (HD) with no apparent heart failure, valvular heart disease, pericardial effusion or coronary artery disease. On the basis of blood pressure patients were classified into two groups: 1) patients with normal arterial pressure (group I) (n = 19), 2) patients with blood hypertension (group II) (n = 12). Cardiac function was assessed immediately before and after HD session. Left ventricular end-diastolic diameter (EDD), left ventricular end-systolic diameter (ESD) and ejection fraction (EF) were calculated. Body weight, heart rate and mean blood pressure (mBP) were also measured. A significant decrease of EDD was noted in both groups during HD but it was less evident in group II (p < 0.05). ESD decreased significantly in group II (p < 0.01) when it did not change in group I. EF increased significantly only in group II (p < 0.05). Blood pressure decreased during HD in both groups. A significant inverse linear association between EF and ESD was noted during HD in both groups (r = -0.685; p < 0.001) but was more evident in group II. There was no association between and EDD (r = 0.199; NS). Similar analysis shows that ESD was significantly with mBP (group II--r = 0.914; p < 0.001, group I--r = 0.565; p < 0.05). Such association were not found for EDD and RR. Only in group II the decrease in mBP was statistical significantly correlated with the increase in EF. The decrease in EDD during HD exists probably due to changes in intravascular volume.(ABSTRACT TRUNCATED AT 250 WORDS)