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Biomedical subjects

G Morrison

Publications and source records attributed to G Morrison.

At least 73 records · Page 4Linked to original sources
PubMed1988

Effect of chronic renal failure on oxaprozin multiple-dose pharmacokinetics.

The effects of renal disease on the steady-state kinetics of oxaprozin were assessed in eight patients on hemodialysis with normal serum albumin levels and eight normal subjects who received six doses. A larger clearance and volume of distribution at steady state for total and unbound oxaprozin occurred in the patients on hemodialysis. The elimination half-lives were not different. The mean total AUC, peak concentration, average steady-state plasma concentration, and trough concentration for total and unbound oxaprozin were decreased in the patients on hemodialysis. These differences are consistent with impaired absorption of oxaprozin in patients on hemodialysis. The higher dose-averaged unbound fraction of oxaprozin in plasma in patients on hemodialysis may be caused by endogenous binding inhibitors. Because clearance was not reduced in patients on hemodialysis, the dose of oxaprozin may not need to be reduced when albumin levels are normal.

Administration, Oral↗
PubMed1988

Universal spondylodiscitis in a patient with erosive peripheral arthritis and apatite crystal deposition.

A patient with erosive peripheral arthritis in whom vasculitis and monoclonal IgG kappa paraprotein were associated with sacroiliitis and widespread destruction of intervertebral discs is reported. Crystals resembling apatite were identified in intervertebral disc material, and we postulate that the discitis was accelerated by apatite deposition. Our case illustrates a unique example of axial involvement in rapidly progressive joint disease.

Adult↗
PubMed1987

Controlled study of renal osteodystrophy in patients undergoing dialysis. Improved response to continuous ambulatory peritoneal dialysis compared with hemodialysis.

To assess the effect of different dialysis modalities on renal osteodystrophy, a controlled study was performed in six patients undergoing continuous ambulatory peritoneal dialysis and six hemodialysis-treated patients. All patients were enrolled at the initiation of dialysis, and age, sex, cause of renal failure, prior treatment of renal osteodystrophy, and baseline serum and bone histologic variables were similar in the two groups. After initial blood samples and bone biopsy specimens (with double-tetracycline labels) were obtained, renal osteodystrophy in both groups received comparable treatment with aluminum hydroxide to maintain serum phosphorus levels between 3.5 and 5.5 mg/dl, and with calcium carbonate and calcitriol to maintain total serum calcium levels between 10 and 11 mg/dl. Blood and bone samples were obtained again after nine months. All patients were asymptomatic at the beginning and end of the study. Phosphorus values were well controlled, and total calcium increased similarly in both groups. Although ionized calcium levels increased in both groups, the final level was higher in hemodialysis-treated patients than in patients undergoing continuous ambulatory peritoneal dialysis (2.82 +/- 0.07 meq/liter and 2.5 +/- 0.05 meq/liter, respectively; p = 0.005). Amino-terminal parathyroid hormone levels normalized in both groups, and histologic improvement of osteitis fibrosa occurred in a similar proportion of patients in both groups; however, quantitative improvement was greater in the hemodialysis-treated patients. Osteomalacia, assessed qualitatively and by dynamic histomorphometric measurements, was ameliorated to a much greater degree in patients undergoing continuous ambulatory peritoneal dialysis compared with hemodialysis-treated patients. Bone aluminum staining was absent in all biopsy specimens. Overall, bone histologic findings improved to a greater degree in patients undergoing continuous ambulatory peritoneal dialysis. When patients undergoing continuous ambulatory peritoneal dialysis or hemodialysis and receiving similar treatment for renal osteodystrophy were compared, patients treated with continuous ambulatory peritoneal dialysis appeared to have a greater improvement in their metabolic bone disease.

Aluminum Hydroxide↗
PubMed1987

Risk factors and outcome of hospital-acquired acute renal failure. Clinical epidemiologic study.

In order to evaluate potential risk factors for the development of hospital-acquired acute renal failure, a case-control study was performed, comparing patients with hospital-acquired acute renal failure with control subjects matched on age, sex, hospital, service of admission, and baseline renal function. The same patients were then reanalyzed utilizing a cohort study design to investigate outcomes from this syndrome. The following elevated odds ratios (95 percent confidence interval) were found while simultaneously adjusting for possible confounding variables using logistic regression: volume depletion, 9.4 (2.1 to 42.8); aminoglycoside use, 5.6 (1.3 to 23.7); congestive heart failure 9.0 (2.1 to 38.9); radiocontrast exposure, 4.9 (1.2 to 19.7); and septic shock, approached infinity, p less than 0.0001. The effect of volume depletion was markedly accentuated in those with diabetes (odds ratio = 1.9) (p less than 0.05). The risk from aminoglycoside use markedly increased with increasing age (p less than 0.002). Finally, the development of hospital-acquired acute renal failure was associated with a marked increase in the risk of dying--the relative risk (95 percent confidence interval) was 6.2 (2.6 to 14.9)--and a marked increase in length of stay, from a median of 13 days in control subjects to a median of 23 days in case subjects (p = 0.005). In conclusion, hospital-acquired acute renal failure is a serious illness. Attempts to prevent it should focus on proved risk factors.

Acute Kidney Injury↗
PubMed1986

Augmentation of NK cell activity by a circulating peptide isolated from the plasma of trauma patients.

Natural killer cell (NK) activity was assessed in patients with nonthermal injury. NK activity was assessed employing a standard 4-hour 51Cr release. Peripheral mononuclear cells from healthy human donors and trauma ward patients served as effector cells at three effector/target ratios. Labeled K562 erythroleukemia cells were used as targets. Multiple dilutions of crude and purified proteolysis inducing factor (PIF), isolated from three septic patients, were evaluated in comparison with other adjuvants. Greater augmentation of anti-K562 activity was obtained in long-term pretreatment of effector cells with adjuvants present as opposed to immediate NK assay. Untreated effectors from trauma patients demonstrated the least amount of baseline NK activity; however, a combination of PIF and interferon showed the greatest cytotoxicity. Untreated healthy cells exhibited a significant (p less than 0.001), twofold greater amount of cytotoxicity than untreated trauma cells. PIF enhances NK activity and may be key to mobilization of host defense in trauma.

Blood Proteins↗
PubMed1986

The acute and chronic effects of indoramin on renal function, hemodynamics, and transport.

The acute and chronic renal effects of indoramin, an alpha 1-adrenoceptor antagonist, were investigated in six normotensive men (mean +/- SEM age, 36 +/- 3 years). Renal clearance studies were done during steady-state water diuresis before administration of indoramin (baseline), 3-4 h after a single 50-mg oral dose (acute study), and after 7 days of treatment with 25 mg twice daily (chronic study). After a single 50-mg oral dose, mean supine blood pressure decreased from 117/76 mm Hg at baseline to 109/74 mm Hg (NS), and glomerular filtration rate and renal blood flow were unchanged. There were small decreases (0.05 less than p less than 0.1) in the fractional excretion of sodium and potassium. After chronic administration (7 days) of indoramin, no significant changes in blood pressure, renal function, renal hemodynamics, or fluid and electrolyte excretion were observed. Mean body weight tended to decrease and fractional sodium excretion increased slightly (NS) after 7 days of indoramin. Plasma renin and aldosterone concentrations tended to increase (NS) after chronic indoramin administration. The results of this study indicate that acute and chronic administration of indoramin does not adversely affect renal function, renal hemodynamics, or fluid and electrolyte excretion in normotensive subjects.

Administration, Oral↗
PubMed1986

Three-dimensional CT reformation in children.

Three-dimensional computed tomographic (CT) reformation has proven useful in the evaluation of congenital malformations of the brain as well as in the surgical approach and postoperative assessment of craniofacial anomalies in children. This technique was performed on 41 patients, of whom eight are presented. The congenital anomalies of semilobar holoprosencephaly and colpocephaly are described. Six representative cases of craniofacial anomalies with pre- and postoperative examinations include Crouzon syndrome, orbital fibrous dysplasia, frontonasal encephalocele, cranial involvement from neurofibromatosis, Treacher-Collins syndrome, and a Tessier III facial cleft. Addition of the dimension of depth provides a view heretofore not obtainable by standard imaging techniques and allows more accurate diagnosis as well as a more specific approach to surgical planning and follow-up.

Brain↗
PubMed1985

The incidence of cleft lip and palate in the Western Cape.

The incidence of cleft lip and palate in the Western Cape was studied using data from two cleft palate centres and from all plastic surgeons in practice in the area. A high incidence was found among coloureds, while the incidences among whites and blacks were similar to figures reported from other countries.

Black People↗
PubMed1985

Factors influencing erythrocyte sedimentation in patients with chronic renal failure.

Erythrocyte sedimentation was studied in stable patients with chronic renal failure free of complicating illnesses. The mean (+/- SD) Westergren erythrocyte sedimentation rate was 49 +/- 26 mm/hr in patients not receiving dialysis and 60 +/- 33 mm/hr in patients receiving hemodialysis. Both values are significantly higher than normal. Because anemia accelerates the Westergren determination, we restudied the patients with the zeta sedimentation ratio (ZSR), a method unaffected by hematocrit. In nine patients not receiving dialysis and 49 patients receiving hemodialysis, the ZSR was significantly higher than normal. The ZSR correlated positively with plasma fibrinogen concentration. Recombination experiments showed that the abnormal factor accelerating erythrocyte sedimentation was a constituent of plasma. Thus, erythrocyte sedimentation is accelerated in stable patients with chronic renal failure and a plasma factor, probably fibrinogen, is responsible. An elevated erythrocyte sedimentation rate in this population lacks diagnostic usefulness.

Blood Sedimentation↗
PubMed1984

Effect of renal impairment and hemodialysis on lorazepam kinetics.

The effect of renal disease on lorazepam kinetics was assessed in three groups: six normal subjects, six patients with renal impairment, and four functionally anephric patients. Subjects received single 1.5- or 3-mg intravenous and oral doses; eight subjects (four normal and four with renal impairment) also received 0.5-mg oral doses three times a day. Lorazepam and lorazepam glucuronide were determined in plasma, urine, and feces by a highly sensitive gas chromatographic method. After single doses, t1/2 and V beta increased in patients, but Cls in the patients (about 85 ml/min) did not differ significantly from that in normals (71 ml/min). Absorption of oral dose was more than 90% and was not impaired by the disease state. Renal and fecal excretion of intact lorazepam accounted for only about 2% of the dose. The major route of drug elimination was hepatic biotransformation to lorazepam glucuronide, an inactive, nontoxic metabolite eliminated by the kidney. In both the normal and renally impaired groups, about 64% of the dose was recovered as glucuronide in urine and less than 0.4% in feces. Fecal excretion contributed very little to the overall elimination of lorazepam and its glucuronide in all groups. Only 8% of the intact drug was removed by 6-hr hemodialysis, but 40% was removed as glucuronide conjugate. Lorazepam kinetics after subchronic dosing were linear. The difference in Clo between the normal and renally impaired groups was not significant. Since the mean steady-state concentration depends on drug clearance only, and since clearance is not altered, no dosage adjustment appears necessary for patients with renal disease.

Administration, Oral↗
PubMed1984

Intraventricular mass lesions.

Determining the precise etiology of an intraventricular mass can be a difficult diagnostic problem. CT and angiographic findings were reviewed in a series of 73 patients who had intraventricular masses. The histologic diagnosis can be suggested preoperatively by an analysis of the frequency of lesions occurring at a given ventricular location, lesion density before and after administration of contrast material, age and sex of the patient, morphologic appearance of the mass, and presence or absence of hydrocephalus. Angiography is useful when meningioma, choroid plexus papilloma and carcinoma, or arteriovenous malformation are considered. The differential features of each diagnostic entity are discussed.

Brain Diseases↗
PubMed1983

Drug prescribing in renal failure: dosing guidelines for adults.

The data base for rational guidelines to safe, efficacious drug prescribing in adults with renal insufficiency are presented in tabular form. Current medical literature was extensively surveyed to provide as much specific information as possible. When information is lacking, however, recommendations are based on pharmacokinetic variables in normal subjects. Nephrotoxicity, important adverse effects, and special considerations in renal patients are noted. Adjustments are suggested for hemodialysis and peritoneal dialysis when appropriate.

Adult↗
PubMed1982

Oxaprozin disposition in renal disease.

Effects of renal disease on the disposition kinetics of oxaprozin, a nonsteroidal antiinflammatory analgesic, were assessed in 15 subjects who were normal, renally impaired, or who had been undergoing hemodialysis. Oral dose clearance (Cloral), volume of distribution at steady-state (V88d), and elimination half-life (t 1/2) did not substantially differ among the three groups. Mean fraction unbound oxaprozin in plasma (fup) increased from 0.08% in the normal group to 0.18% and 0.28% in the two azotemic groups. Consequently, unbound drug kinetic parameters, including intrinsic clearance (Clint) and V88du of unbound drug were reduced from 2.9 l/hr/kg and 193 l/kg in normal subjects to approximately 1.6 l/hr/kg and 91 l/kg in azotemic patients. The smaller volume of distribution is consistent with a decrease in oxaprozin tissue binding in azotemia. The decreased plasma and tissue binding and lower Clint suggest that, in the treatment of azotemic patients with rheumatoid arthritis, the dose of oxaprozin should begin at 600 mg once a day.

Adult↗