Hemodynamic effect of inhaled nitric oxide in dilated cardiomyopathy patients on LVAD support

Recently it has been shown that inhaled nitric oxide (NO), which has been proven to contribute to improvement in critical pulmonary hypertension, may provide a favorable effect early after left ventricular assist device (LVAD) support. To improve right ventricular function, inhalation of NO was added to treatment with conventional catecholamines for four consecutive dilated cardiomyopathy (DCM) patients following institution of LVAD. In two patients 1 hr after inhalation of NO, central venous pressure (CVP), mean pulmonary arterial pressure (PAm), and pulmonary vascular resistance (PVR) were improved. These results led to better LVAD output and resulted in an adequate cardiac index. On the other hand, a right VAD (RVAD) was implemented in one patient whose high CVP, PAm, and PVR continued; he was weaned after 8 days of RVAD support. Another patient who had a high CVP but normal PAm and PVR before and after inhalation of NO had no improvement in his hemodynamic state. These data suggest that inhaled NO may improve systemic circulation by reducing right ventricular afterload and may become a promising and convenient therapy before placing RVAD in DCM patients under LVAD support. RVAD should be conducted in patients with right ventricular failure or when pulmonary hypertension is associated with impaired right ventricular reserve, even after inhalation of NO.     

Hemodynamic effects of arbutamine

This study examined the hemodynamic effects of arbutamine, a synthetic catecholamine, in 12 patients with and 7 patients without coronary artery disease. Arbutamine produced a balanced positive inotropic (increase in left ventricular dp/dt) and chronotropic effect (increase in heart rate).     

Hemodynamic effect of molsidomine in coronary patients with heart failure with clinically manifest nitrate tolerance

Objective of the present study was to investigate the hemodynamic response to molsidomine in nitrate tolerance state. In 13 out of 16 patients (5 women, 11 men, 62 [53/71] years [median, 25%/75%-percentiles]) with chronic heart failure (NYHA stage II-III; median angiographic ejection fraction (EF) 55%) and coronary artery disease (stenosis of at least 75%) the development of tolerance under the continuous infusion of high doses of nitroglycerin (10 mg/h) was observed. Tolerance was defined as a benefit loss of at least 50% of the initial nitroglycerin effect with respect to the pulmonary capillary wedge pressure. Compared to the state of tolerance to nitroglycerin the infusion of 10 mg molsidomine over 15 minutes resulted in significant changes of the median values (25%/75%-percentiles) of mean right atrial pressure from 16 (12/21) to 9 (5/12) mmHg (p < 0.01), mean pulmonary artery pressure from 37 (30/40) to 24 (20/30) mmHg (p < 0.001), mean pulmonary capillary wedge pressure from 22 (18/25) to 15 (10/22) mmHg (p < 0.01) and cardiac output from 4.1 (3.5/4.7) to 5.2 (4.2/5.6) l/min (p < 0.01). This action of molsidomine corresponded to a complete overcoming (> 100%) of the benefit loss observed during the development of nitrate tolerance with respect to all above-mentioned hemodynamic parameters. Under parallel maintainance of nitroglycerin infusion (10 mg/h) these hemodynamic effects of molsidomine, i.e. at least 90% of the peak effect, lasted for 147 (130/182) minutes (median, 25%/75%-percentiles). Baseline values, i.e. a loss of at least 75% of the molsidomine effect, were only reached after 363 (319/412) minutes (median, 25%/75%-percentiles).(ABSTRACT TRUNCATED AT 250 WORDS)     

Opsonic effect of equine plasma from different donors

The ability of equine plasma from different donors to enhance phagocytic capacity was assessed in neutrophils obtained from seven foals, aged 7-8 days (Study A), and from seven adult horses (Study B). Neutrophils were allowed to phagocytize fluorescent yeast cells opsonized with plasma from one of three donors or with pooled serum, all previously frozen (-18 degrees C) and thawed. The results were analysed by flow cytometry. In study A, fresh autologous foal serum was also used for opsonization, and in study B, heat-inactivated plasma and pooled serum were used in addition to untreated samples. The plasma from donor GN induced a higher number of truly phagocytic neutrophils (mean 78%) than did plasma from donors GD (68%), OD (66%) and pooled serum (59%) when neutrophils from foals were used (p < 0.05). Similar results were obtained when adult neutrophils were used. Phagocytosis was markedly reduced with beat-inactivated plasma as a result of there being fewer phagocytic neutrophils and less phagocytized material per cell. The opsonic capacities of the autologous foal sera were lower than that of adult donor plasma in six out of seven foals. It is concluded that there is significant individual variation in the opsonic activity amongst plasma donors with similar serum IgG concentrations. The results were consistent irrespective of whether neutrophils from adults or foals were used.     

Hemodynamic evaluation of the effect of percutaneous transluminal angioplasty for atherosclerotic disease of the vertebrobasilar arterial system

The relationship between clinical improvement after percutaneous transluminal angioplasty (PTA) and hemodynamic condition in vertebrobasilar insufficiency was evaluated in 43 patients between 45 and 86 years of age with clinically symptomatic atherosclerotic stenotic lesions in the posterior circulation. The 43 patients had a total of 51 stenotic lesions, including 17 in the first segment of the vertebral artery, 32 in the fourth segment of the vertebral artery, and two in the basilar artery. Angiography was performed and cerebral perfusion was measured with technetium-99m-hexamethyl-propyleneamine oxime single photon emission computed tomography before and after administration of 10 mg/kg acetazolamide prior to and more than 7 months after PTA. Mean stenosis was 81.3 +/- 7.4% before PTA, but only 41.5 +/- 17.4% at follow-up. Eighteen of the 24 patients with improved neurological condition after PTA had subnormal (< mean - 2 SDs) cerebral perfusion before PTA. Twenty of these 24 patients had subnormal vasodilatory response to administration of acetazolamide before PTA. Clinical improvement following PTA was noted in only one of the 12 patients with a single stenotic lesion of the first segment, but in 23 of the 31 patients with intracranial stenotic or multiple stenotic lesions. PTA in the posterior circulation is indicated for patients with atherosclerotic stenotic intracranial lesion or multiple stenotic lesions who have subnormal cerebral perfusion and low vasodilatory response to administration of acetazolamide.     

Hemodynamic mechanism of vasovagal syncope

Vasovagal syncope is a common clinical problem, however the hemodynamic mechanism is not clearly understood. The aim of the present study was to investigate the circulatory control mechanism of vasovagal syncope provoked by the head-up tilt test. Thirty two patients with recurrent unexplained syncope were studied using a head-up (60 degrees) tilt test. The electrocardiogram, arterial blood pressure, pulmonary arterial pressure and central venous pressure were monitored continuously, and the cardiac output was measured by the thermodilution method. Twenty patients (62.5%) had positive tilt test responses, of which 12 developed typical vasovagal syncope with marked hypotension and bradycardia; the others developed hypotension without bradycardia. There were five women and seven men with a mean age (+/- SD) of 53.3 +/- 15 years. The effect of head-up tilt resembled that of hypovolemia. The central venous pressure, pulmonary capillary wedge pressure and cardiac output declined with an increase of heart rate and systemic vascular resistance. However the mean blood pressure was maintained. During vasovagal syncope, the heart rate and blood pressure fell precipitously and significantly, the cardiac index was reduced from 2.22 +/- 0.43 to 1.51 +/- 0.32 liters/min/m2 (p value < 0.05) and the systemic vascular resistance index decreased from 3,689 +/- 859 to 1,999 +/- 543.9 dynes s cm5/m2 (p value < 0.05). The results of our study showed that both reduction of cardiac output and withdrawal of sympathetic vasoconstriction tone contribute to the development of hypotension in vasovagal syncope.     

Hemodynamic characteristics in hypertension

Recent studies have outlined both the importance and limitations of hemodynamic studies in hypertension. Characterization of any type of hypertension cannot be established in terms of cardiac output or total peripheral resistance alone. It depends more on the way in which various factors (hemodynamics, volume, humoral and neural) interrelate than on disturbances of one factor alone. More studies are needed, not so much of each variable alone as of correlations among those variables, e.g. correlations between humoral factors and hemodynamic characteristics. Further, hemodynamic analyses must be extended beyond calculations of TPR to evaluation of other variables such as magnitude and distribution of intravascular volume, indices of aortic distensibility, of velocity of ventricular ejection and of cardiac performance. Interpretation of the results must also take into account factors such as hemodynamic setting, age of patient, neurogenic stimulation and structural changes amongst others. Careful attention to these variables will allow more accurate conclusions regarding characteristics of different types of hypertension, and patterns of response to therapy. Accurate hemodynamic characterization may help orient diagnosis and a rational choice of treatment in initial stages but specially for evaluation of resistant cases.     

The effect of antisynaptosomal plasma membrane antibodies on memory

Antisynaptosomal plasma membrane antibodies were introduced through an infusion cannula into rat brain and their effects on behaviour were tested. Four different learning paradigms were used, two appetitively and two aversively motivated, to show impairment in memory retrieval. No effects were found on aquisition, motor activity, or motivation.     

Hemodynamic assessment of obstructive aortoiliac disease

Angiographic demonstration of obstructive aortoiliac disease is of paramount importance prior to surgery. Obstructive disease in the femoral popliteal system can only be surgically relieved if inflow is adequate. Severely stenotic lesions may be missed by angiography due to the oblique course of the iliac arteries and inability to obtain right angle views. Translumbar downstream catheterization of the abdominal aorta and puncture of both femoral arteries allows simultaneous pressure recordings. The injection of 30 mg of papaverine into the femoral artery assures maximal vasodilatation mimicking conditions under exercise. A minimal gradient at rest may become obvious following the injection of papaverine, indicating hemodynamically significant disease and warranting surgical correction. The technique has proved to be simple and valuable, and there have been no complications.     

Microsatellite analysis of plasma DNA from patients with clear cell renal carcinoma

Deletions of DNA sequences on chromosome 3p [loss of heterozygosity (LOH)] are characteristic of clear cell renal carcinoma, which accounts for about 80% of all renal malignancies. Comparing tumor DNA to DNA from normal cells, LOH analysis of microsatellite sequences has aided in molecular diagnosis of renal carcinoma. Because clinically useful tumor markers do not exist for this cancer entity, the aim of the present study was to detect chromosome 3p microsatellite alterations (LOH and microsatellite instability) in plasma DNA from patients with clear cell renal carcinoma. Four chromosome 3p microsatellites (D3S1307, D3S1560, D3S1289, and D3S1300) were amplified by fluorescent PCR using DNA isolated from normal blood cells and plasma of 40 patients. Corresponding tumor DNA was available from 21 patients. Analyzing PCR products on an automated DNA sequencer, we found LOH in at least one locus in 25 plasma samples (63%), and 14 plasma samples (35%) exhibited LOH at more than one locus. Microsatellite instability of plasma DNA was detectable in one patient (3%). No significant association of advanced (>T2N0M0) tumor stages with LOH in plasma DNA could be demonstrated. If present, modifications of plasma DNA and tumor DNA were identical. No alterations of plasma DNA were found in healthy controls. Analysis of plasma DNA from patients with clear cell renal carcinoma reveals tumor-specific microsatellite alterations and may therefore have diagnostic potential as a molecular tumor marker.     

Hemodynamic changes during laparoscopic cholecystectomy

Hemodynamics during laparoscopic cholecystectomy under general anesthesia (isoflurane in N2O/O2 (50%)) were investigated in 15 nonobese ASA Class I patients by using invasive hemodynamic monitoring including a flow-directed pulmonary artery catheter. During surgery, intraabdominal pressure was maintained automatically at 14 mm Hg by a CO2 insufflator, and minute ventilation was controlled and adjusted to avoid hypercapnia. Hemodynamics were measured before anesthesia, after the induction of anesthesia, after tilting into 10 degrees head-up position, 5 min, 15 min, and 30 min after peritoneal insufflation, and 30 min after exsufflation. Induction of anesthesia decreased significantly mean arterial pressure and cardiac index (CI). Tilting the patient to the head-up position reduced cardiac preload and caused further reduction of CI. Peritoneal insufflation resulted in a significant increase (+/- 35%) of mean arterial pressure, a significant reduction (+/- 20%) of CI, and a significant increase of systemic (+/- 65%) and pulmonary (+/- 90%) vascular resistances. The combined effect of anesthesia, head-up tilt, and peritoneal insufflation produced a 50% decrease in CI. Administration of increasing concentrations of isoflurane, via its vasodilatory activity, may have partially blunted these hemodynamic changes. These results demonstrate that laparoscopy for cholecystectomy in head-up position results in significant hemodynamic changes in healthy patients, particularly at the induction of pneumoperitoneum.     

The elevation of plasma DNA in patients with systemic lupus erythematosus is attributable to increased DNA release and defective DNA binding of mononuclear cells

BACKGROUND: Although immunoprecipitable DNA has been found in a subgroup of patients with systemic lupus erythematosus (SLE) exhibiting systemic vasculitis and/or central nervous system involvement, the mechanism for elevated plasma DNA in these patients is poorly understood. METHODS: The plasma DNA concentrations and reactivity of serum and lymphocytes to six species of double-stranded DNA from calf thymus, human placenta, Escherichia coli, Micrococcus lysodeikticus, Clostridium perfringens and poly (dG.dC). poly (dG.dC) were measured in twenty-seven patients with active SLE. To understand the mechanism of increased plasma DNA in SLE, the DNA binding and release of the mononuclear cells were examined. RESULTS: Compared with the controls, the incidence of the presence of plasma DNA was markedly increased in SLE (59.3% in SLE vs. 7.4% in controls) as detected by counterimmunoelectrophoresis. Except for DNA from Clostridium perfringens, the reactivity of lupus sera to various DNA samples was significantly higher than that of the controls. The reactivity of lymphocytes to 6 species of DNA (as defined by 3H-thymidine incorporation of the cells) was also higher in SLE patients. In DNA binding and releasing experiments, patients with SLE were found to have decreased 3H-DNA binding activity (0.169 +/- 0.018 micrograms/2 x 10(6) cells in SLE vs. 0.283 +/- 0.02 micrograms/2 x 10(6) cells in controls, p = 0.001) but to have increased spontaneous release of DNA (1,465 +/- 412 cpm in SLE vs. 630 +/- 179 cpm in controls, p = 0.0173) in mononuclear cells. CONCLUSIONS: The results suggest that some subsets of lymphocytes can be sensitized by different DNA samples in vivo to increase endogenous DNA release from mononuclear cells, which in addition to decreased DNA clearance as has been previously reported, may be responsible for the elevation of plasma DNA in patients with SLE.     

Blood flow resistance during hemodilution: effect of plasma composition

To explore the extent of cross-border care seeking among Canadians, we analyzed the growth and distribution of Ontario Health Insurance Plan expenditures for medical care services provided in the United States to Ontario residents from 1987 to 1995. Although total out-of-province spending is low relative to in-province spending, there is evidence of cross-border care seeking for cardiovascular and orthopedic procedures, mental health services, and cancer treatments. However, combined with a preliminary investigation of cross-border patient care seeking using nonpublic funding sources, these analyses do not support the perception of widespread cross-border medical care seeking by Ontario residents.