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PubMed1995

A phase II trial of extracorporeal plasma immunoadsorption of patient plasma with PROSORBA columns for treating metastatic breast cancer.

BACKGROUND: Circulating immune complexes (CIC) have been implicated as a cause of malignancy-associated immunosuppression and disease progression. Previous attempts to remove CIC by pheresis or immunoadsorption over a Staphylococcus aureus protein A column have resulted in a few clinical responses, however the relationship between removal of CIC and tumor response in these trials is not clear. Based on these data, a Phase II trial of immunoadsorption over a Staphylococcus aureus protein A column was initiated for patients with metastatic breast cancer. The authors sought to correlate clinical response with amount of CIC eluted from the columns after immunoadsorption. METHODS: The potential role of extracorporeal immunoadsorption was determined using protein A columns in treating patients with advanced breast cancer. An immunoadsorbent column composed of protein A was bound covalently to an inert silica matrix (PROSORBA [IMRE Corporation, Seattle, WA] column). Patients underwent a 3-hour on-line procedure phlebotomizing 2000 ml of whole blood. Patient plasma was passed over PROSORBA columns to remove immunoglobulin G (IgG) and IgG-related CIC. The treated plasma then was reunited with formed elements and reinfused into the patient. Patients were treated three times per week for a total of 4 weeks. Analyses of tumor-associated Le(x)-containing CIC adsorbed on PROSORBA columns were performed using an enzyme-linked immunosorbent assay technique with a monoclonal antibody specific for the Le(x) moiety. RESULTS: Sixteen patients were entered in this Phase II study, with a mean age of 57 years (range, 40-69 years). All patients received prior treatment for Stage IV breast cancer. The median number of PROSORBA treatments was 12 (range, 1-15 treatments). No toxicities or major objective responses were seen noted the 16 patients. One patient with severe chest wall pain had a symptomatic response. The remaining patients all had disease progression. Analyses of column eluates from 11 patients in this study revealed no detectable Le(x)-containing immune complexes when compared with control subjects. CONCLUSIONS: Immunoadsorption over a Staphylococcus aureus Protein A column had no meaningful antitumor activity in patients with advanced breast cancer. In this cohort of patients, an elevated level of Le(x) CIC was not confirmed in the eluates of the column compared with a control group of patients without cancer.

Adult↗
PubMed1975

Utility of fasting essential amino acid plasma levels in formulation of nutritionally adequate diets IV: lowering of human plasma cholesterol and triglyceride levels by lysine and tryptophan supplementation.

The administration of capsules containing L-lysine monohydrochloride (0.205 g) and L-tryptophan (0.069 g) three times daily after meals resulted in a significant drop in plasma cholesterol and triglyceride levels. The proportion of amino acids in the blend was derived from the average fasting plasma essential amino acid profile.

Adult↗
PubMed1985

Plasma lipoproteins as drug carriers: pharmacological activity and disposition of the complex of beta-sitosteryl-beta-D-glucopyranoside with plasma lipoproteins.

The ability of plasma lipoproteins to act as carriers in site-specific drug delivery systems was evaluated by determining the disposition and pharmacological effects of beta-sitosteryl-beta-D-glucopyranoside (SG, 3). In the disposition studies, [3H]SG was absorbed from the intestinal tract by the formation of chylomicrons and was specifically associated with lipoproteins in vivo. [3H]SG was incorporated into various rat plasma lipoproteins in vitro. [3H]SG complexed with the lower density lipoproteins (d less than 1.063 g/mL), especially with the intermediate density lipoproteins (1.006 less than or equal to d less than 1.019 g/mL) which following intravenous administration to rats. In pharmacological studies, the hemostatic effect of SG in mice and the inhibitory effect of SG on vascular permeability in rats were only observed after intravenous administration of the complexes of SG with the lower density lipoproteins. The same results were obtained after the intravenous administration of the complexes of SG with human and mouse lipoproteins.

Animals↗
PubMed2005

Investigation of the metabolic fate of 2-, 3- and 4-bromobenzoic acids in bile-duct-cannulated rats by inductively coupled plasma mass spectrometry and high-performance liquid chromatography/inductively coupled plasma mass spectrometry/electrospray mass spectrometry.

Inductively coupled plasma mass spectrometry (ICPMS) has been used to determine the rate and routes of excretion of bromine following the intraperitoneal administration (50 mg kg(-1)) of 2-, 3- and 4-bromobenzoic acids to male bile-duct-cannulated rats. Analysis of urine and bile for (79/81)Br using ICPMS showed that all three bromobenzoic acids were rapidly excreted (82-98%) within 48 h of dosing, primarily via the urine. High-performance liquid chromatography/inductively coupled plasma mass spectrometry (HPLC/ICPMS) was then used to obtain metabolite profiles for bile and urine. These profiles revealed that extensive metabolism had taken place, with the unchanged bromobenzoic acids forming a minor part of the total of compound-related material detected. Concomitant MS studies, supplemented by alkaline hydrolysis, enabled the identification of the major metabolite of all three of the bromobenzoic acids as a glycine conjugate. Ester glucuronide conjugates were also identified, but formed only a small proportion of total.

Animals↗
PubMed2006

Determination of refractory elements in atmospheric particulates using slurry sampling electrothermal vaporization inductively coupled plasma optical emission spectrometry and inductively coupled plasma mass spectrometry with polyvinylidene fluoride as chemical modifier.

Electrothermal vaporization (ETV) inductively coupled plasma optical emission spectrometry (ICP-OES) and inductively coupled plasma mass spectrometry (ICP-MS) with polyvinylidene fluoride (PVDF) as chemical modifier are critically compared for the determination of refractory elements in coal fly ash and airborne particulates. The atmospheric particulates that collected on a PVDF filter were introduced into the graphite furnace in the form of a slurry by dissolving the filter in dimethylformamide, and the dissolved filter PVDF, along with additional added PVDF powder, was used as a chemical modifier for subsequent ETV-ICP-OES and ETV-ICP-MS determination. The vaporization behaviors of analytes (Ti, Zr, V, Mo, Cr, La) in ETV-ICP-OES/MS were studied in detail, and the optimal ETV operating parameters were obtained. Under the optimized operating conditions, the detection limits of target elements were 0.08-2.7 ng m(-3) for ETV-ICP-OES and 0.5-50 pg m(-3) for ETV-ICP-MS, respectively, with analytical precisions of 3.5-7.3% for ETV-ICP-OES and 3.9-9.6% for ETV-ICP-MS, respectively. The tolerable amounts of matrix elements for ETV-ICP-OES are higher than for ETV-ICP-MS. Both ETV-ICP-OES and ETV-ICP-MS were used to directly determine the trace refractory elements in coal fly ash and airborne particulates and the analytical results are comparable.

Journal Article↗
PubMed1997

Water permeability, Lp, of the mouse sperm plasma membrane and its activation energy are strongly dependent on interaction of the plasma membrane with the sperm cytoskeleton.

Two parameters fundamental to cell cryobiology are the water permeability (hydraulic conductivity), Lp, and its activation energy, EA. The Lp can be calculated from two experimental determinations: the critical osmolality, Osmcrit, at which 50% of the cells lyse, and the time, tcrit, to 50% lysis in a highly hyposmotic medium, based on the assumption that the cells swell to lysis with minimal resistance to swelling. We have reported [Cryobiology 32, 220-238 (1995)] that mouse sperm in hyposmotic medium show minimal swelling and so fail to meet this assumption. The concept that resistance to swelling was due to anchoring of the plasma membrane through cytoskeletal interaction was examined by treating mouse sperm with 5 microM cytochalasin D to depolymerize the cytoskeletal filamentous actin (f-actin), whose presence was established by staining with fluorescently labeled phalloidin. Diminution of fluorescence due to loss of f-actin induced by cytochalasin D was shown by flow cytometry. Mouse sperm treated with cytochalasin D showed tail curling in hyposmotic medium, similar to that observed with bovine and human sperm, indicating that the standard swelling model was applicable to these cells. Two sets of Lp values were calculated from tcrit: one using individual means of Osmcrit and one using the mean of means of Osmcrit between 37 and 4 degrees C, as these individual means were not significantly different. Values (micron.min-1.atm-1), respectively, were 9.95, 7.15 (37 degrees C); 1.51, 0.91 (22 degrees C); 0.54, 0.78 (12 degrees C); 0.47, 0.50 (4 degrees C); 0.33 (0 degree C); and 0.36 (-3 degrees C). Arrhenius plots gave EA = 13.7 and 11.7 kcal/mol, respectively. Values of t1/2 were calculated from the first-order rate constants characterizing the kinetics of cell lysis at the higher four temperatures; Lp values calculated from these, and the two sets of Osmcrit values described were 5.70, 4.09 (37 degrees C); 1.18, 0.71 (22 degrees C); 0.62, 0.90 (12 degrees C); and 0.34, 0.37 (4 degrees C). Arrhenius plots gave EA = 14.2 and 11.0 kcal/mol, respectively. We propose that these EA values are characteristic of the plasma membrane relatively unperturbed by cytoskeletal interactions. In untreated sperm, decrease of Lp with decreasing temperature and presence of cryoprotectant and the cytoskeletal interactions all act to hamper the sperm cells' ability to respond to osmotic stress encountered during freezing and thawing, such that these cells are especially sensitive to cryodamage.

Actins↗
PubMed1979

Freeze-fracture study of the chromaffin cell during exocytosis: evidence for connections between the plasma membrane and secretory granules and for movements of plasma membrane-associated particles.

Exocytosis was studied in acetylcholine-stimulated bovine adrenal medulla. During a pre-exocytotic stage, chromaffin granules are found in juxtaposition to the plasma membrane and separated from it by an electron dense space 25--27 A in width. Freeze-fracture studies show this stage to be characterized by connections between the granules and the plasma membrane. These connections are apparently cytoplasmic but bridge both membranes; they are presumably proteinaceous, but their exact nature remains to be elucidated. Later stages of exocytosis were also studied by the freeze-fracture technique; a typical feature is the lack of intramembrane particles around the fusion site. Both connections and membrane particle movement are discussed in terms of recent biochemical findings.

Acetylcholine↗
PubMed1982

Plasma renin activity and plasma aldosterone concentration in infants with various potassium intakes.

Plasma renin activity (PRA) and aldosterone concentration (PA) were measured in 20 healthy infants from 1 to 12 months of age during normal (3.03 mmol/kg/d) and high (5.20 mmol/kg/d) potassium intake. PRA did not change between regimes. PA rose significantly from 618 pg/ml during normal to 1136 pg/ml during high potassium intake. It is concluded that the potassium intake should be taken into consideration when studying plasma aldosterone in infancy.

Aldosterone↗
PubMed1984

Effect of indapamide on renal plasma flow, glomerular filtration rate and arginine vasopressin in plasma in essential hypertension.

Renal plasma flow (RPF), glomerular filtration rate (GFR), arginine vasopressin in plasma (AVP), free water clearance (CH2O) and blood pressure (BP) were determined in 11 patients with essential hypertension at the end of 3 consecutive periods of observation each of 6 of weeks duration; indapamide 2.5 mg daily was given in period 2 and placebo in periods 1 and 3. RPF and GFR were reduced by 9% and BP by 9%/14% supine and 14%/12% standing during indapamide treatment. Changes in renal haemodynamics were not correlated with those in BP. AVP was not significantly altered by indapamide and was not correlated with BP. Indapamide reduced CH2O possibly due to the reduction in GFR. It is concluded that indapamide evidently induces redistribution of the cardiac output, with enhanced muscle blood flow and reduced renal perfusion, and that AVP does not seem to be involved in blood pressure regulation in mild to moderate essential hypertension under basal conditions.

Adult↗
PubMed1985

Effect of pinacidil on blood pressure, plasma catecholamines and plasma renin activity in essential hypertension.

Pinacidil, a new cyanoguanidine derivative, is an antihypertensive agent with arteriolar vasodilating properties, which acts on precapillary resistance vessels. A trial was carried out in 30 patients with essential hypertension WHO I-II. The treatment period was divided into three phases. Hydrochlorothiazide (HCTZ) and amiloride were administered for 4 weeks in Phase 1 and supine and standing blood pressure decreased significantly. During Phase 2 pinacidil was added to HCTZ/amiloride for the following 3 months. A further significant reduction in blood pressure was obtained. In the next period of treatment (Phase 3) patients were divided into two groups. For 1 month Group A (15 patients) received pinacidil alone and Group B (15 patients) received HCTZ/amiloride. Conventional laboratory blood tests in all patients remained unchanged during treatment. Reported side effects during Phase 2 were headache (2 patients), dizziness (3 patients), palpitations (2 patients) and ankle oedema (2 patients). Plasma renin activity was slightly increased at the end both of Phases 1 and 2. Plasma catecholamines were increased but not significantly at the end of Phase 2 as compared to Phase 1. The results indicate that pinacidil is effective in lowering blood pressure in mild to moderate essential hypertension.

Adult↗
PubMed1989

Effects of low-dose atenolol on postural and postprandial changes in heart rate, blood pressure, venous plasma catecholamines, and plasma renin activity.

The administration of a single dose of atenolol 50 mg 1 h before a standard 3100 kJ cold meal in fasting healthy subjects reduced the supine preprandial heart rate and systolic blood pressure, and blunted the postural and postprandial rises in mean heart rate and systolic blood pressure relative to placebo. It did not affect the preprandial supine diastolic blood pressure, nor the postural rise and postprandial drop in diastolic blood pressure. Preprandial administration of atenolol blunted the postural and postprandial rises in mean plasma renin activity, and it enhanced the rise in plasma noradrenaline during eating in the sitting position, and the postprandial concentrations of noradrenaline. The findings do not permit the conclusion that beta 1-adrenergic stimulation was the predominant cause of these atenolol-responsive changes.

Adult↗
PubMed1980

Effects of two angiotensin II analogues on blood pressure, plasma aldosterone concentration, plasma renin activity and creatinine clearance in normal subjects on different sodium intakes.

Two angiotensin II analogues (AIIA), 1-sarcosine, 8-isoleucine angiotensin II ([Sar, Ile]-AII) and 1-sarcosine, 8-alanine angiotensin II ([Sar, Ala]-AII), were infused in six normal volunteers on high, regular and low sodium diets. The agonist and antagonist activities of these AIIA on blood pressure (BP), plasma aldosterone concentration (PAC), creatinine clearance and plasma renin activity were examined. Both AIIA had agonistic pressor activities in subjects on high and regular sodium diets, [Sar, Ile]-AII being more potent than [Sar, Ala]-AII. Both AIIA caused similar elevation of PAC in subjects on high and regular sodium diets, and an equally fall in PAC in subjects on a low sodium diet. Both AIIA strongly antagonized the rise in BP, the increase in PAC and the reduction of Ccr induced by AII administration in subjects on all three sodium diets. The results indicate that both AIIA can be used to examine the activity of the renin-angiotensin system in patients with hypertension, and they also suggest that AII interaction with its receptors differs in different target tissues.

1-Sarcosine-8-Isoleucine Angiotensin II↗
PubMed1988

Effect of dichlorvos on the activity of lipoprotein lipase from adipose tissue, on plasma lipids and postheparin lipolytic plasma activity in rats.

The activity of lipoprotein lipase (LPL) from adipose tissue, the postheparin lipolytic activity (PHLA) in plasma, and the content of plasma lipoproteins were investigated in rats poisoned with dichlorvos (DDVP). Administration of a single dose (50% LD50) resulted in inhibition of LPL and PHLA; the greatest inhibition was observed at 24 and 48 h after administration of the posticide. The metabolism of serum lipoproteins was also altered; the content of triacylglycerols in very low density lipoproteins (VLDL) and low density lipoproteins (LDL) fractions was increased; the content of cholesterol was increased in VLDL and high density lipoproteins (HDL) fractions, and decreased in the LDL fraction. On repeated administration of small DDVP doses (5% LD50) the greatest changes were observed after 90 days of intoxication. The levels of all three determined lipoprotein fractions, as well as PHLA, were decreased. The LPL activity in adipose tissue was slightly raised. The results suggest that DDVP interferes with the metabolism of lipids.

Adipose Tissue↗
PubMed1986

The effect of atrial natriuretic peptide on plasma renin activity, plasma aldosterone, and urinary dopamine in man.

The acute natriuretic effect of human atrial natriuretic peptide (ANP) has been well described in man. We have now studied possible hormonal mediators of this effect. We studied six healthy volunteers on two occasions when they received either an infusion of ANP of 1.5 pmol X kg-1 X min-1 for 30 min followed by 15 pmol X kg-1 X min-1 for a further 30 min, or matching vehicle infusions in a randomized single-blind fashion. On the placebo day, plasma renin activity (PRA) rose from 1.26 +/- 0.08 to 1.57 +/- 0.14 ng A1 X ml-1 X h-1, while on the ANP study day PRA fell from 1.45 +/- 0.15 to 1.28 +/- 0.05 ng A1 X ml-1 X h-1 (p less than 0.01). No significant changes were found in plasma aldosterone concentrations or in urinary dopamine excretion. These results provide evidence that ANP suppresses renin release in man.

Aldosterone↗
PubMed1982

Fasciola hepatica: plasma ascorbic acid, plasma iron and iron-binding capacity in experimentally infected sheep.

Six sheep were infected with about 520 Fasciola hepatica metacercariae. Plasma ascorbic acid decreased after infection attaining minimum values by week 10 and subsequently increased. Plasma iron concentrations were elevated during the first 6 weeks of exposure and then decreased till week 10; the levels approached pre-infection values at weeks 11-13 and again dropped. The iron-binding capacity rose during infection especially between weeks 13 and 19.

Animals↗
PubMed1979

Interrelationships between sodium clearance, plasma aldosterone, plasma renin activity, renal hemodynamics and blood pressure in renal disease.

This study was designed to evaluate the role of aldosterone, glomerular filtration and blood pressure on sodium excretion in renal disease. Sodium clearance (CNa), plasma aldosterone (PA), plasma renin activity (PRA), glomerular filtration rate (GF), paraaminohippurate clearance (CPAH) and blood pressure were measured simultaneously in 19 normal subjects, 38 patients with benign essential hypertension, 3 with renal artery stenosis, 48 with chronic glomerulonephritis, 20 with the nephrotic syndrome, 24 with tubulo-interstitial disease and 21 with a renal homograft. CNa was significantly depressed in patients with the nephrotic syndrome. Mean PA and PRA were increased in renal artery stenosis but within the normal range in other groups. CNa correlated inversely with PA in all groups but one (tubulo-interstitial disease). CNa correlated directly with GF in the nephrotic syndrome and with the mean blood pressure (mBP) in chronic glomerulonephritis and tubulo-interstitial disease. PA correlated directly with PRA and inversely with GF or CPAH in most groups. It is concluded that PA is an important determinant of the basal natriuresis in renal disease with the exception of tubulo-interstitial nephropathies. In the nephrotic syndrome sodium retention is largely determined by the interaction of PA and GF. In chronic nephropathies, but not in benign essential hypertension, the fractional sodium excretion is partly blood pressure-dependent. Impairment of renal function is often accompanied by a rise in PA.

Adolescent↗
PubMed1990

Blood plasma proteins on polyurethane and alkylsiloxane plasma-treated polyurethane surfaces. Dynamic approach by stimulus-response technique. Part 2. Evaluation of adsorption data by moment technique.

In this study, interactions of blood proteins (i.e. albumin and fibrinogen) with polyurethane biomaterial surfaces were investigated in an in vitro bead column test circuit using a stimulus-response technique. The dynamic sorption process of radiolabelled proteins on the surfaces was followed by detecting the radioactivity at the exit stream of the column, which was the response of a pulse stimulus at the inlet. The mathematical model was described and solved using 'parameter estimation by cybernetic moment technique', and the adsorption rate constants of plasma proteins on different biomaterial surfaces were calculated. By evaluation of the response curves with standard and cybernetic moment techniques, the following results were obtained. Albumin and fibrinogen adsorption is competitive, and the competition is strongly dependent upon the surface characteristics of the biomaterial. Preadsorption or preferential adsorption of albumin decreases the fibrinogen adsorption, and therefore increases the biocompatibility of material surface. Adsorption of blood plasma proteins are irreversible. The moment technique can also be used for the evaluation of stimulus-response data of biological systems, to determine the process parameters.

Adsorption↗