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B Bailey

Publications and source records attributed to B Bailey.

At least 55 records · Page 3Linked to original sources
PubMed1994

Comparison of 5-fluorouracil anabolite levels after intravenous bolus and continuous infusion.

The levels of 5-fluorouracil (5FU) and its anabolites in the serum, bile, pancreatic juice, liver, pancreas, and skeletal muscle of dogs were compared after single bolus administration and after continuous infusion. Six dogs had a bolus of 5FU (15 mg/kg) and were studied for 120 min. Five dogs had a continuous infusion of 5FU (30 mg/kg) and were studied for 24 h. After the bolus infusion, serum 5FU levels were initially high and then declined, whereas anabolite levels gradually increased over 45 min. Within 2 h, anabolite levels exceeded 5FU levels in tissues but were undetectable in bile and pancreatic juice. During the continuous infusion, anabolite levels in serum increased more rapidly than 5FU levels and remained significantly higher for 24 h. Anabolite levels also exceeded 5FU levels in bile, pancreatic juice, pancreas, and muscle but not in the liver. Continuous infusion of 5FU produced higher levels of the anabolites than did bolus infusion and maintained constant levels throughout the infusion period.

Animals↗
PubMed1994

5-Fluorouracil pharmacokinetics in patients with metastatic colorectal carcinoma after high-dose leucovorin.

The effect of high-dose leucovorin on 5-fluorouracil (5-FU) pharmacokinetics was studied in 5 patients with metastatic colorectal carcinoma. Patients received leucovorin, 500 mg/m2, and 5-FU, 600 mg/m2, on 1 day and 5-FU alone 1 week later. Plasma concentrations of 5-FU and 5-FU anabolites were determined over 2 hr. Levels of 5-FU were highest initially and then fell rapidly. Plasma concentration-time curves suggested a two-compartment kinetic model. Anabolite levels exceeded 5-FU levels after 15 min. When leucovorin was administered, the time of distribution (t1/2 alpha for 5-FU increased from 8.9 +/- 2.4 to 12.8 +/- 2.5 min (p < 0.0005) and the volume of distribution (Vd) increased from 0.129 +/- 0.039 to 0.237 +/- 0.033 L/kg (p < 0.03). Elimination and plasma clearance of 5-FU were unchanged. Anabolite levels were initially lower (p < 0.05) with leucovorin, suggesting increased tissue extraction of 5-FU.

Aged↗
PubMed1994

Life in Nah Nah Land.

Explore the source record for details and available documents.

Emergency Medical Services↗
PubMed1993

Enhancement of axial resolution in fluorescence microscopy by standing-wave excitation.

The use of fluorescence microscopy for investigating the three-dimensional structure of cells and tissue is of growing importance in cell biology, biophysics and biomedicine. Three-dimensional data are obtained by recording a series of images of the specimen as it is stepped through the focal plane of the microscope. Whether by direct imaging or by confocal scanning, diffraction effects and noise generally limit axial resolution to about 0.5 microns. Here we describe a fluorescence microscope in which axial resolution is increased to better than 0.05 microns by using the principle of standing-wave excitation of fluorescence. Standing waves formed by interference in laser illumination create an excitation field with closely spaced nodes and antinodes, allowing optical sectioning of the specimen at very high resolution. We use this technique to obtain images of actin fibres and filaments in fixed cells, actin single filaments in vitro and myosin II in a living cell.

3T3 Cells↗
PubMed1993

Hepatopancreatic uptake and elimination of 5-fluorouracil after intravenous injection.

The efficacy of 5-fluorouracil (5FU) chemotherapy depends, in part, upon maintaining adequate intracellular levels of active metabolites. The uptake, distribution and elimination of 5FU and 5FU-anabolites were determined after an intravenous bolus infusion of 5FU, 15 mg kg-1, and the relationship between serum and tissue levels were evaluated. In six dogs samples of liver, pancreas, rectus abdominus muscle, blood, bile and pancreatic juice were collected at 0, 15, 45, 90 and 120 min. Bile and pancreatic juice levels of 5FU followed the same pattern as the serum, rising rapidly and falling exponentially, suggesting elimination by simple diffusion. Elimination of anabolites was more complex. Tissue levels of anabolites were highest in the liver and peaked later than in the pancreas and muscle. They were unrelated to serum levels of 5FU. The higher and more sustained levels of 5FU-anabolites in the liver may be responsible for some of the beneficial effects of 5FU chemotherapy on hepatic tumours.

Animals↗
PubMed1993

Visualisation of arterial structure in vivo with intravascular ultrasound.

BACKGROUND: Contrast angiography provides a silhouette of the arterial lumen, but does not give information about arterial wall structure. Catheter-tip ultrasound transducers can now provide a cross-sectional image of the arterial wall. This study examined the pathological correlation of intravascular ultrasound images and the accuracy of ultrasound measurements of vascular geometry. METHODS: Intravascular ultrasound images were obtained with a mechanically rotated catheter-tip transducer and recorded on videotape. Initial validation studies were performed in fresh, post-mortem arterial specimens, which were filled with saline at physiological pressures. Ultrasound images at specific sites were compared with the pathological findings at that site and measurements of luminal diameter were compared with corresponding angiographic measurements. Subsequently, intravascular ultrasound was employed to examine the aorta, ilio-femoral and coronary arteries in patients undergoing balloon angioplasty. RESULTS: The pathological correlations showed that intravascular ultrasound can detect early initial thickening and mild atherosclerotic lesions that do not result in luminal deformation. Ultrasound images provided definition of calcified, fibrotic and lipid-filled lesions. Ultrasound measurements of luminal diameter correlated well with pathology measurements (r = 0.93), as did ultrasound measurements of plaque area (r = 0.89). The in vivo studies demonstrated that intravascular ultrasound can define atheroma lesions not evident on contrast angiography and permits detailed evaluation of the results of interventions such as balloon angioplasty. CONCLUSIONS: Intravascular ultrasound provides a unique window upon arterial structure and pathology in humans. Ultrasound images allow accurate measurements of vascular geometry and define early atheromatous lesions that are not evident with angiography.

Arteries↗
PubMed1993

The convergent and discriminant validity of the Chapman Scales.

Our study investigated the convergent and discriminant validity of five of Chapman's Schizotypia Scales (i.e., Physical Anhedonia, Revised Social Anhedonia, Perceptual Aberration, Magical Ideation, and Impulsive Nonconformity; L.J. Chapman, J.P. Chapman, & Raulin 1976, 1978; Eckblad & L.J. Chapman, 1983) and Meehl's Schizoidia Scale (Meehl, 1964) within a sample of 50 personality disordered subjects, many of whom possessed schizotypic traits. It was hypothesized in part that all five of the Chapman scales and the Schizoidia Scale would correlate with the schizotypal personality disorder; the Physical Anhedonia and Revised Social Anhedonia Scales would correlate with the schizoid personality disorder, whereas the Magical Ideation and Perceptual Aberration Scales would not; the Physical and Revised Social Anhedonia Scales would not correlate with the avoidant personality disorder; and the Impulsive Nonconformity Scale would correlate with the borderline and antisocial personality disorders. Only the hypotheses concerning the avoidant personality disorder and the Schizoidia Scale were not supported. The findings remained even when the effects of state anxiety and state depression were controlled. Implications of the findings with respect to the validity of the Chapman and Schizoidia Scales and the personality disorders are discussed.

Adult↗
PubMed1992

Effect of lignocaine on arginine-vasopressin plasma levels: baseline or induced by frusemide.

1. To assess whether or not lignocaine influences baseline and frusemide-induced (5 mg kg-1) plasma concentrations of arginine-vasopressin (AVP), 2 groups of rabbits received an infusion of lignocaine (130 micrograms min-1 kg-1) for 6 h. Lignocaine-induced changes in AVP plasma concentrations were substantiated by measurement of diuresis and natriuresis and hepatic plasma flow, by means of an infusion of indocyanine green (ICG) (249 micrograms min-1 kg-1). 2. Baseline plasma AVP levels were 4.9 +/- 0.9 pg ml-1 (+/- s.e.), and following lignocaine, these values were reduced to 0.7 +/- 0.1 pg ml-1 (P less than 0.01). Frusemide increased AVP levels to 134.1 +/- 73.6 pg ml-1 (P less than 0.05) and lignocaine totally prevented this increase, e.g. mean AVP levels of 2.7 pg ml-1. 3. Lignocaine enhanced baseline diuresis secondary to an increase in free water clearance; none of the experimental conditions affected the diuresis and natriuresis induced by frusemide. 4. Frusemide reduced the hepatic plasma flow and this decrease was not reversed by the infusion of lignocaine. 5. It is concluded that in healthy rabbits lignocaine reduces baseline secretion of AVP and its antidiuretic effect; in addition, lignocaine prevents the rise in AVP induced by frusemide.

Animals↗
PubMed1991

Diffusion resistances between ADH-induced vacuoles and the extracellular space in rabbit collecting duct: evidence that most vacuoles are intracellular, endocytic compartments.

Large vacuoles form in the renal collecting duct following the onset of antidiuretic hormone (ADH)-stimulated water reabsorption. The aim of the present study was to test two alternative hypotheses regarding the origins of these structures: (1) the vacuoles constitute basilar, extracellular spaces that dilate as water flows through these spaces from cells into the peritubular compartment; or (2) the vacuoles represent intracellular, endocytic compartments that dilate during water reabsorption due to enhanced fluid phase endocytosis. Fluorescence-digital imaging microscopy was used to visualize the uptake into vacuoles of a hydrophilic fluorochrome (6 methoxy-N-[3 sulfopropyl] quinolinium) whose fluorescence is markedly quenched by halides. During their formation, most vacuoles (67%) accumulated the fluorochrome from the peritubular bath and trapped the dye well after (greater than 60 min) washing it from the bath. The spatial pattern of fluorescence within individual vacuoles indicated that the dye was trapped within these structures as a fluid-phase marker and was not bound to the vacuole margins. The fluorescence of dye trapped within vacuoles was virtually unaltered by changes in peritubular Cl- or Br- concentration that elicit dramatic quenching of dye-fluorescence in bulk solution, as expected if there exists a high diffusion resistance between the interiors of these structures and the peritubular space. These results indicate that most ADH-induced vacuoles represent endocytic compartments that are not directly connected to the extracellular space.

Animals↗
PubMed1991

Stress-induced gastric lesions and the synthesis of prostaglandins and leukotrienes.

Prostaglandin E2 renders the mucosa of the GI tract more resistant to acute injury by aspirin, acid, bile salts, and stress, whereas leukotrienes promote inflammation and retard healing of ulcers. The relationship of stress ulcer formation to changes in the activities of prostaglandin synthetase and lipoxygenase was evaluated in this study. After a 24 hr fast, 10 rats were stressed by the cold-restraint method for 4 hr and 10 rats were not stressed. Rats were terminated, stomachs were excised, the number of lesions were counted, and the nonulcerated mucosa was assayed for prostaglandin E2 and leukotriene synthesis. The mucosa was minced, washed in buffered saline, and then incubated for 10 min in a 1.3 mM sodium arachidonate solution containing a nonionic detergent (poloxamer 188), NaCl, KCl, KPO4, glutathione, hemin, MgSO4 and Hepes at pH 8.0. An ANOVA was used to compare the groups. Following stress the number of gastric lesions increased from 0.7 +/- 0.6 to 13.5 +/- 2.6, while leukotriene synthesis increased from 173 +/- 20 to 2170 +/- 187 pg/mg/min. A shift in synthesis from prostaglandins to leukotrienes in the mucosa appears to be detrimental to cytoprotection.

Animals↗
PubMed1991

Phrenic nerve injury. A prospective study.

In cardiac surgery, topical iced saline solution slush has become an important adjunct in maintaining myocardial hypothermia during cardioplegic arrest. One complication of this technique is phrenic nerve injury (PNI). In an attempt to reduce the incidence of PNI, a prospective study was undertaken to evaluate the impact of phrenic nerve insulation on PNI during cardiac surgery. Seventy-six consecutive patients who underwent coronary revascularization constituted the control group (CG) and were compared with 76 patients who underwent a similar procedure with the addition of phrenic nerve insulation. In the intervention group (IG), a foam insulation pad was placed between the heart and the pericardium in an effort to reduce exposure of the phrenic nerve to iced saline solution slush. There was no difference in major demographic descriptors or operative variables between the CG and the IG, except that the internal mammary artery was used more frequently in the IG (64 percent vs 36 percent, p = 0.0006). The in-hospital mortality was similar between the groups (CG, 0.0 percent; IG, 1.3 percent; p = 1.0); however, the incidence of roentgenographically diagnosed PNI was much greater in the CG (14/76 patients [18 percent] vs 0/76 patients [0 percent]; p = 0.0006). Patients with and without PNI were similar with regard to age, gender, aortic cross clamp time, cardiopulmonary bypass time, and number of grafts (p greater than 0.05). All unilateral PNI occurred on the left. Three patients with bilateral PNI required tracheostomy and prolonged mechanical ventilation. In-hospital mortality was similar for patients with and without PNI (0 percent vs 0.7 percent), but mean postoperative hospital stay for patients with clinically diagnosed PNI was longer than for those without PNI (32 vs 11 days, p = 0.04). This prospective study demonstrates that the incidence of PNI can be significantly reduced by the routine use of phrenic nerve insulation.

Adult↗
PubMed1991

Measurement of prostaglandin G/H synthase and lipoxygenase activity in the stomach wall by HPLC.

A method for the determination of prostaglandin G/H synthase and lipoxygenase activities in tissues was developed and employed with rat gastric mucosa samples. Tissues and microsomes were incubated in a buffer containing nonionic detergent and 1.32 mM arachidonic acid for 10 min. Following extraction with ethyl acetate, the oxidation products of arachidonic acid were derivatized with panacyl bromide. A reversed-phase column and a quaternary mobile phase were used to separate and quantitate the panacyl bromide esters of prostaglandin E2 and leukotriene C4/D4. Prostaglandin G/H synthase and lipoxygenase activities were determined in gastric mucosa and were 371 +/- 66 and 173 +/- pg/mg/min, respectively.

Animals↗