Biomedical subjects
J L Bell
Publications and source records attributed to J L Bell.
Outpatient percutaneous central venous access in cancer patients.
A 1-year experience of percutaneous subclavian catheterization in outpatients with cancer was reviewed to document reliability, safety, and cost. There were 763 catheter insertions attempted with prospective documentation of complications in 664 consecutive patients. Catheter insertion was successful in 722 attempts (95%). There were only 13 pneumothoraces (2%). Thirty catheters required repositioning (4%). The average catheter duration was 191 days (range: 0 to 892 days). Fifty-six catheters (8%) were removed because of suspected infection. Documented catheter sepsis occurred in 21 patients (3%); catheter site infection occurred in 8 patients (1%). Thus, only 0.22 infections per catheter year occurred during this 382 catheter-year experience. The estimated cost of catheter insertion was $562, which is one-third the estimated cost for tunneled catheters ($1,403) and for reservoir devices ($1,738). In our experience, percutaneous subclavian catheterization is a reliable, cost-effective method compared with tunneled or reservoir devices, with an equivalent incidence of catheter-related infections. The cornerstone of our success with this program is a staff dedicated to catheter care and intensive patient education. In centers where a large number of patients require central venous access, percutaneous catheterization should be the technique of choice.
Hydraulically-induced convective solute transport across the rabbit peritoneum.
Transport of solutes during osmotically-induced transperitoneal ultrafiltration is less than would be predicted based upon rates of transperitoneal solute diffusion. Previous workers have hypothesized that osmotically-induced convective solute transport occurs only in small pores at the arteriolar end of peritoneal capillaries, whereas solute diffusion occurs only through large venular pores. We tested this heteroporosity hypothesis in the eviscerated New Zealand White rabbit by determining sieving coefficients (S) for creatinine, p-aminohippurate (PAH) and neutral dextran during hydraulically-induced transperitoneal ultrafiltration (N = 13). A hydraulically-induced driving force directs convective solute transport through the same capillary pores employed for diffusion; therefore S for all solutes should approach unity if the heteroporosity hypothesis is valid. S for creatinine and PAH were respectively 0.72 +/- 0.03 and 0.67 +/- 0.05, values lower than unity and not different from those previously determined during osmotically induced ultrafiltration. Mean S for dextran were relatively independent of molecular size, ranging from 0.50 at 13 A to 0.40 at 50 A. Thus, dextran S were higher than those previously determined during osmotically induced ultrafiltration yet still less than unity. Control experiments (N = 6) suggested that only surface area and not transport characteristics were altered by evisceration. These observations demonstrate that the heteroporosity hypothesis fails to completely describe both diffusive and convective transport properties of the peritoneum.
Disopyramide and N-monodesalkyl disopyramide in serum and breast milk.
Maternal serum and breast milk were obtained to determine the concentration of disopyramide (DP) and its metabolite N-monodesalkyl disopyramide (NMD) from a woman requiring antidysrhythmic drug therapy. Infant serum and urine were also obtained for drug concentrations. DP 450 mg tid resulted in peak maternal serum concentrations of 4.0 micrograms/mL and 2.2 micrograms/mL for DP and NMD, respectively. Breast milk concentrations averaged 1.06 and 6.24 times the serum levels for DP and NMD, respectively. No DP was measurable in the infant's serum except for cord blood, which contained 0.7 micrograms/mL DP, 26 percent of simultaneous maternal concentration, and 0.9 micrograms/mL NMD, which represented 43 percent of the maternal concentration. Infant urine collected over an eight-hour period contained 3.3 micrograms/mL of DP and 3.7 micrograms/mL of NMD.
Effect of starvation and sampling time on plasma alkaline phosphatase activity and calcium homeostasis in the rat.
The effect of starvation and sampling time on plasma alkaline phosphatase activity, total plasma calcium concentration and whole blood ionized calcium concentration was determined in the rat. Starvation caused a significant fall in total and ionized calcium concentrations as well as in alkaline phosphatase activity. These changes were accompanied by a fall in whole blood pH and an increase in the anion gap and a decrease in urinary excretion of calcium. These indices were restored to normal following refeeding. There was no change in serum 25-OH vitamin D concentrations following starvation for 3 days. Alkaline phosphatase activity showed a pattern compatible with the presence of a circadian rhythm when sampling took place between 0800 and 1800 h. Total and ionized calcium concentrations did not show such a rhythm when animals were fed the present diet.
Economic impact of reducing hospitalization for mastectomy patients.
In 1985, two policies designed to reduce hospitalization charges for mastectomy patients were instituted at the M.D. Anderson Cancer Center at Houston. The first was a policy of "same-day" admissions for elective surgery patients, and the second was early postoperative discharge for mastectomy patients with suction catheter drains in place. The economic savings resulting from these policies was analyzed by comparing demographics, operation, stage of disease, hospital stay, hospital charges, and complications for two groups of patients. Fifty-nine consecutive mastectomy patients treated between 1983 and 1984, before these policy changes, had "standard management" consisting of hospital admission 24 hours before surgery and discharge only after the surgical drains were removed. Sixty-one consecutive mastectomy patients treated between 1986 and 1987, after these policy changes went into effect, were admitted from the recovery room after surgery and were discharged with drainage catheters in place, usually within 72 hours. All operations were performed by the same faculty surgeon as a representative experience of the General Surgery faculty. The average hospital stay was reduced from 10.5 to 4.3 days. A mean 39% reduction in hospital charges (from $4867.00 to $2981.00) was achieved by instituting the policies of "same-day" admission and early postoperative discharge with drainage catheters in place. Complication rates were not changed. Implementation of this policy resulted in an estimated savings of $750,000.00 in the hospital care of approximately 400 patients treated at the M.D. Anderson Cancer Center at Houston each year. Adjustments in patient care delivery systems from a predominantly inpatient to an outpatient setting required changes in outpatient nursing responsibilities (although not in new personnel). Patient education and written instructions for home care of surgical wounds and drainage catheters were essential for implementing an early discharge policy. With these facts in mind, hospital admission on the day of operation and early postoperative discharge with drainage catheters in place should be the goal for most mastectomy patients.
Fibronectin concentrations in plasma in peripheral vascular disease.
Fibronectin (Fn) concentrations were measured immunoturbidimetrically in plasma of normal subjects and patients with peripheral vascular disease (PVD) before and after venous compression, which caused Fn concentrations to increase in both normal subjects and PVD patients. Basal Fn concentrations and those after 10-min compression were not significantly different in normal subjects and PVD patients. Five minutes after the release of compression, Fn had consistently declined in normal subjects and reverted to baseline values; in contrast, in PVD patients values either increased further or decreased inconsistently. Thus the Fn concentration at 15 min was significantly (P less than 0.001) greater in PVD patients than in normal subjects. Plasma albumin concentrations, measured in parallel to ensure that changes in Fn concentrations were not nonspecific, increased to a greater extent in normal subjects than in PVD patients and reverted to normal after the removal of compression. The Fn/albumin ratio remained unchanged in normal subjects after venous compression, whereas that in PVD patients increased and remained higher, even after decompression. The sustained increase in plasma Fn concentrations and in the Fn/albumin ratio in PVD patients after venous compression may indicate endothelial injury.
Effect of starvation on biochemical indices of renal function in the rat.
The effect of starvation on urinary output and biochemical indices of renal function was investigated in rats. Starvation resulted in a marked fall in water intake. Urinary output paradoxically increased during the first day following starvation, but fell dramatically thereafter. Urinary creatinine excretion and creatinine clearance fell markedly, but plasma creatinine concentration did not alter. Plasma urea concentration and urinary urea excretion fell. Plasma sodium concentration increased, whilst plasma potassium concentration did not alter; urinary sodium and potassium excretion fell. Plasma bicarbonate concentration fell marginally, but the anion gap increased to a greater extent. Following re-feeding, water intake and urine output increased, as did urinary creatinine excretion and creatinine clearance. Plasma urea and urinary urea concentrations, as well as sodium and potassium excretion, increased. Plasma bicarbonate increased and the anion gap decreased. These indices improved within 2 days of re-feeding and were restored to normal in 5 days.
Determination of free digoxin concentrations in serum for monitoring Fab treatment of digoxin overdose.
A rapid method for assessing the free digoxin concentration in the serum of digoxin-overdosed patients receiving treatment with digoxin-specific Fab fragments has been developed. For this method, a protein-free ultrafiltrate is prepared from the patient's serum, and the digoxin in the ultrafiltrate (free digoxin) is measured by fluorescence polarization immunoassay. Both the inaccuracies associated with measurements of total digoxin by immunoassay in the presence of Fab and the long turnaround time associated with measurements of free digoxin by equilibrium dialysis were avoided. Good correlation was observed between measurements of free digoxin by this ultrafiltration technique and by equilibrium dialysis. The ultrafiltration method was used to evaluate the concentrations of free digoxin in a digoxin-overdosed patient treated with Fab at our hospital. In retrospect, the results suggest that her hospital stay could have been shortened by a timely appreciation of her increased concentration of free digoxin. Using the ultrafiltration method, one can determine free digoxin concentrations quickly, conveniently, and accurately in the clinical laboratory. This procedure therefore should be a valuable aid in monitoring the efficacy and adequacy of Fab treatment.
Warfarin administration increases uric acid concentrations in plasma.
The effect of warfarin administration on plasma uric acid was investigated. A representative sample of patients on long-term warfarin treatment had a significantly higher concentration of uric acid in plasma than did age-matched patients with comparable plasma urea concentrations who were not taking warfarin. In women, this association was observed only in patients with normal values for plasma urea, not in those with high values. In contrast, in men this association was present in both groups (normal and high plasma urea). In a longitudinal study involving patients, their plasma uric acid significantly increased after warfarin administration. There was no significant change in the renal clearance of uric acid after a single dose of warfarin in normal, healthy volunteers; this contrasts with the increase observed with other coumarin anticoagulants. Our findings suggest that the increase in plasma uric acid noted with warfarin administration is probably due to an increase in uric acid production and may predispose to gout those patients who are on long-term therapy with warfarin.
Immunoturbidimetric assay of slight albuminuria with a centrifugal analyzer.
Explore the source record for details and available documents.
Penetrating cardiac trauma.
During a 10 1/2 year interval ending in June 1980, 47 patients with penetrating cardiac trauma were managed at The University of Alabama Medical Center. Thirty-nine patients (83%) were male. Mean age was 31 years (range, 13 to 69). Thirty-two patients (68%) sustained stab wounds (SW) and 15 patients (32%) gunshot wounds (GSW). Forty-two patients (89%) arrived hypotensive (systolic blood pressure less than 90 mm Hg). Twenty-seven patients (57%) had evidence of cardiac tamponade (central venous pressure greater than 15 cm H2O) and 25 of these 27 patients were also in shock. Forty patients (85%) presented with a normal sinus rhythm and seven patients (15%) had an idioventricular rhythm or asystole. Overall mortality was 23% (11 of 47 patients). Forty-three per cent of the patients sustaining GSW (6/14) died compared to 17% (5/33) of the patients with SW (p = 0.04). Mortality for the patients in shock was 26% and for those with cardiac tamponade 15%. Mortality was 16% for the patients with both shock and cardiac tamponade. Thirteen per cent of the patients in normal sinus rhythm died, while 87% of the patients with idioventricular rhythm or asystole died (p less than 0.0001). Mortality in penetrating cardiac trauma remains high, particularly in patients with GSW and in those patients presenting with an idioventricular rhythm or asystole.
Environmental effects on urinary volumes, biochemical constituents and their inter-relation.
This study has found low 24-h urine volumes in British expatriates in Saudi Arabia and suggests the possibility of urate stone formation in spite of the air-conditioned environment in which they were living. Urine volume was shown to be significantly correlated with calcium excretion in both sexes and to urate and sodium in males. Differences in 24-h urine concentrations of some but not all constituents between British-born subjects living in Britain and Saudi Arabia have been demonstrated.
The prevalence of diabetes mellitus in male Saudi Arabs.
The prevalence of diabetes mellitus in 1385 males in the Al-Kharj area of Saudi Arabia was studied using the WHO criteria for screening and interpretation of glucose tolerance tests[1]. The prevalence was found to increase with age. No diabetic patients were found in the less than or equal to 24 year age group and only one (0.3%) in the age range: 25-34 years. There were seven (2.6%) in the age range: 35-44 years, 17 (9.6%) in the age range: 45-54 years, six (11%) in the age range: 55-64 years and three (23%) in the age range: greater than or equal to 65 years. The cases detected were relatively symptom free, but 65% of the diabetic patients were overweight.
In memoriam: Sumner L. Koch: 1888-1976.
Explore the source record for details and available documents.
Serum enzyme changes in patients receiving antituberculosis therapy with rifampicin or p-aminosalicylic acid, plus isoniazid and streptomycin.
Explore the source record for details and available documents.
Evaluation of the Vickers D300 for routine analysis of urea, bilirubin, total protein and albumin in plasma.
Explore the source record for details and available documents.
Purification and comparative properties of isoenzymes of nicotinamide-adenine dinucleotide phosphate-isocitrate dehydrogenase from rat heart and liver.
1. Rat liver and heart major isoenzymes of NADP-isocitrate dehydrogenase have each been purified about 100-fold by a combination of ammonium sulphate fractionation and chromatography on ion-exchange cellulose and their properties compared. 2. The properties were similar in respect of pH, inhibition by Hg(2+) and Michaelis constants for isocitrate and NADP. 3. Some of the properties of the isoenzymes were different. 4. The heart isoenzyme was activated about 210% by 0.8m-ammonium sulphate whereas the liver isoenzyme was unaffected. The heart isoenzyme showed greater sensitivity to inactivation by heat (30 degrees C for 30min), whereas the liver isoenzyme was more sensitive to inactivation by p-chloromercuribenzoate and by Cu(2+). 5. The Michaelis constants with 3-acetylpyridine-adenine dinucleotide phosphate showed a twofold difference between liver and heart isoenzyme. 6. The differential sensitivity to heat and its mainly non-cytoplasmic location may be an explanation of the failure of plasma isocitrate dehydrogenase activity to increase after a myocardial infarction.