Biomedical subjects

S E Halley

Publications and source records attributed to S E Halley.

6 recordsLinked to original sources

PubMed1995

Dialysate protein losses with bleach processed polysulphone dialyzers.

We measured dialysate protein losses from polysulphone dialyzers undergoing repetitive processing with bleach and formaldehyde. The entire dialysate was collected during the first, fifth and tenth use of F-80 dialyzers. Dialysate protein concentration was 1.5 +/- 0.4 mg/dl N = 11 +/- SEM) during the first use, 2.1 +/- 0.3 mg/dl during the fifth use and 3.6 +/- 0.5 mg/dl (N = 10) during the tenth use. In a follow-up study, dialyzers were evaluated for up to 25 uses. After 12 to 15 uses dialysate protein was 7.9 +/- 0.8 mg/dl (N = 13), after 16 to 20 uses; 12.0 +/- 1.2 mg/dl (N = 13) and after 23 to 25 uses; 19.9 +/- 2.1 mg/dl (N = 5). Mean dialysate volume was 83.9 +/- 1.1 liters (N = 63) yielding total protein losses of up to 20.7 grams per treatment. Dialysate albumin losses, which were unmeasurable during the first use of the dialyzers, revealed a similar increase with reuse resulting in a mean value of 14.4 +/- 3.2 mg/dl after 23 to 25 reuses (N = 5). Dialysate beta-2 microglobulin (beta 2m) levels were 1.05 +/- 0.13 mg/l for dialyzers bleached < 10 times (N = 32) versus 1.54 +/- 0.15 mg/liter for dialyzers bleached > 10 times (N = 31, P < 0.02 vs. < 10 reuses). A random sampling of dialyzers processed without bleach for 8, 14, 15, 24 and 25 reuses revealed minimal protein losses, ranging from 1.4 to 2.7 mg/dl with no relation to reuse number and no measureable albumin.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1990

Plasma exchange with a rotating filter.

We have modified a rotating filter system to provide therapeutic plasma exchange. Seventeen patients underwent 188 treatments. Blood flows to the filter ranged from 75 to 100 ml/min; mean filtration fraction was 64 +/- 1% (+/- SE, N = 188). Mean plasma removal rate per treatment was 40.2 +/- 0.6 ml/min; net plasma removed per treatment was 3231 +/- 53 ml (N = 188); mean treatment time was 83 +/- 2 minutes (N = 188). Mean percent decline in platelet count was 15 +/- 4% (N = 46). Immunoglobulin kinetics were evaluated in order to validate our method of treatment prescription. The apparent volume of distribution (AVD) for each immunoglobulin class was compared to our estimate for plasma volume (EPV). The fraction AVD/EPV for IgG was 0.97 +/- 0.04 (N = 14), for IgA was 0.87 +/- 0.04 (N = 13) and for IgM was 0.96 +/- 0.3 (N = 26). Use of the EPV allowed for accurate prediction of treatment results. Correlation between expected and actual decline in serum levels revealed an r value of 0.86 for IgG (P = 0.0002), 0.88 for IgA (P = 0.0001), and 0.57 for IgM (P less than 0.003). We conclude that a rotating filter system can provide a highly efficient means of plasma exchange. The use of a simplified method of estimating plasma volume allows for a reliable prediction of treatment results.

Blood Coagulation↗

PubMed1989

Comparative renal effects of intravenous administration of fenoldopam mesylate and sodium nitroprusside in patients with severe hypertension.

We studied the renal effects of intravenous administration of fenoldopam mesylate, a dopamine-1 agonist, vs sodium nitroprusside following acute reduction of blood pressure (BP) in 11 patients with severe hypertension (supine BP, 168/124 to 252/135 mm Hg). Following randomization (open-label), timed urinary and plasma samples for clearance of urea and creatinine and excretion of sodium, potassium, and calcium were obtained as well as plasma renin activity for a two-hour collection prior to infusion, during a two-hour period of BP control (supine diastolic BP, 95 to 110 mm Hg), and following two hours off the drugs. Mean arterial pressure was lowered similarly with the two drugs (-22% on fenoldopam vs -20% on nitroprusside; P = NS), and neither plasma renin activity nor plasma aldosterone concentration were changed by either drug. However, patients receiving fenoldopam had significant increases in urinary flow and excretion of sodium, potassium, and calcium, whereas patients receiving nitroprusside had no changes in these parameters. Patients receiving fenoldopam had a net fluid balance of -334 mL from the end of baseline to the end of the treatment period, while the nitroprusside group had a positive balance of 382 mL. Thus, these findings show that acute BP reduction with fenoldopam is associated with both a diuresis and natriuresis in severely hypertensive patients while lowering BP with nitroprusside does not predictably alter renal function and causes a moderate expansion in volume.

Adult↗

PubMed1988

Renovascular hypertension in moyamoya syndrome. Therapeutic response to percutaneous transluminal angioplasty.

Moyamoya ("puff of smoke") syndrome is a disease of children and young adults caused by fibromuscular dysplasia of the internal carotid and proximal cerebral arteries and is rarely associated with hypertension. We report a 34-year old woman with moyamoya syndrome who presented with symptomatic severe hypertension associated with unilateral renal artery stenosis. The patient underwent percutaneous transluminal angioplasty of the right renal artery with subsequent improvement in blood pressure control on reduced, and later, no antihypertensive therapy. This case illustrates that moyamoya syndrome may be an intracranial manifestation of a systemic arterial disorder. Renal artery stenosis may, in appropriate cases, be managed by percutaneous transluminal angioplasty.

Adolescent↗

PubMedDate not supplied

One year's experience using a rotating filter for therapeutic plasma exchange.

The authors previously demonstrated the feasibility of using a rotating filter system for therapeutic plasma exchange. They now report on the technical details of a 1 year clinical experience. Seventeen patients underwent 188 treatments. Hemoaccess was provided by antecubital veins (147 Rx), femoral catheters (37 Rx), or an a-v fistula (3 Rx). Blood flows ranged from 75 to 100 ml/min. Net plasma removed per treatment was 3,231 +/- 53 ml (mean +/- SE, n = 188). Mean plasma removal rate per treatment was 40.2 +/- 0.6 ml/min; mean treatment time was 83 +/- 2 min. Platelet counts before and after treatment revealed a 15 +/- 4% decline (n = 46 Rx). Despite filtration fractions up to 86% there was no evidence of significant membrane plugging or hemolysis. For semiselective removal of cholesterol, the rotating filter was used in a cascade system with a secondary filter. Eighty percent of processed plasma was returned to the patient, but the treatment time was prolonged by 37% and the total cholesterol removed was 26% less when compared with the single pass system. The authors conclude that an inexpensive rotating filter can provide a highly efficient plasma exchange. The inherent efficiency of this system must be considered when evaluating its use with secondary filtration techniques.

Cholesterol↗

PubMedDate not supplied

Evaluation of a rotating filter for use with therapeutic plasma exchange.

A rotating filter system was evaluated for therapeutic plasma exchange. In vitro and in vivo studies revealed sieving coefficients of clinically important molecules to be essentially 1, with no substantial decline over time. A modification of the tubing system allowed for continuous flow, double access operation. Placing the collection bag at the base of the machine provided excellent plasma removal rates with only minimal blood flows. A rotating filter can provide a highly efficient system for therapeutic plasma exchange.

Adult↗