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Biomedical subjects

S Erill

Publications and source records attributed to S Erill.

At least 37 records · Page 2Linked to original sources
PubMed1983

Procaine hydrolysis defect in uraemia does not appear to be due to carbamylation of plasma esterases.

Procaine esterase activity in plasma from patients with renal failure is decreased by 40%. Since cyanate is formed from urea and readily carbamylates certain blood proteins, a possible role for cyanate in the depression of plasma esterase activity in uraemic patients was considered. However, in vitro carbamylation of normal plasma in a range similar to that detected in uraemic patients did not influence procaine esterase activity. Kinetic analysis of the reaction showed that the maximal hydrolyzing capacity but not the Km in uraemic plasma was diminished (5.0 +/- 0.3 X 10(-5) moles hydrolyzed per litre of plasma per minute and a Km of 3.9 +/- 0.2 X 10(-5) mol/l in plasma from normal volunteers as compared to 3.1 +/- 0.1 X 10(-5) mol/l/min and 3.5 +/- 0.2 X 10(-5) ml/l in plasma from patients with renal failure). Therefore, not carbamylation but rather a decrease in enzyme synthesis is the likely explanation for the lower rate of procaine hydrolysis in uraemic plasma.

Adult↗
PubMed1982

Effects of carbamylation of plasma proteins and competitive displacers on drug binding in uremia.

The effects of in vitro carbamylation of plasma with potassium cyanate on the binding of sulfisoxazole and diazepam have been investigated. Incubation of plasma with potassium cyanate produced varying degrees of carbamylation of plasma proteins which were associated with a decrease in the binding of sulfisoxazole (100 mg/l), a drug bound to site I on the human albumin. Scatchard plots showed that this decreased binding resulted from a decrease in affinity without changes in the number of binding sites. Similar changes were detected in uremia. Carbamylation of plasma proteins did not affect the binding of diazepam (3 mg/l), a drug bound to site II. The plasma protein binding of sulfisoxazole and diazepam was decreased in samples from uremic patients. Charcoal treatment did not modify the binding of sulfisoxazole to normal or carbamylated plasma while it reduced, but did not normalize, the binding defect in uremic plasma. On the other hand, charcoal treatment brought the binding of diazepam in uremic plasma to normal values. It seems that only drug binding site I is carbamylated in uremia, while competitive displacers bind to sites I and II.

Adult↗
PubMed1982

A study of package inserts of potentially toxic drugs.

Information contained in the package inserts of drugs chosen as potential causes of blood dyscrasia, renal toxicity, hepatotoxicity, and cardiac toxicity has been studied. Chloramphenicol and pyrazolones were chosen as representatives of drugs that could produce blood dyscrasia, aminoglycosides and cephaloridine as potential nephrotoxic agents, isoniazid and monoamine oxidase inhibitors as possible hepatotoxic drugs, and tricyclic antidepressants and digitalis as drugs of recognized cardiac toxicity. Adverse effects were clearly described in only 27.8% of the package inserts, whereas 40.3% did not mention them, and 15.7% specifically stated that the product was devoid of adverse effects. Information about the type of toxicity that led to the selection of drugs included in this study was uncommon in most cases.

Drug Labeling↗
PubMed1981

Plasma protein binding of etomidate in different age groups and in patients with chronic respiratory insufficiency.

Plasma protein binding of etomidate, an intravenous anesthetic agent of basic nature, has been studied in healthy subjects of different age groups and in patients with chronic respiratory insufficiency. No differences were detected in the plasma protein binding of etomidate between young children and young adults, but elderly subjects exhibited decreased binding. Low levels of serum albumin may account in part for this decreased binding, but differences in the amount of etomidate bound per mol of albumin and in affinity constants for the binding were also apparent between young adults and elderly individuals. Although plasma protein binding of etomidate may also be decreased in patients with chronic respiratory insufficiency, further studies are needed to clarify this point.

Adult↗
PubMed1980

Effects of disease and acetazolamide on procaine hydrolysis by red blood cell enzymes.

Procaine hydrolysis in vitro has been studied in whole blood, plasma, and washed erythrocytes. Esterase activity was higher in whole blood than in either diluted plasma or resuspended erythrocytes. Eserine and echothiophate specifically inhibited plasma procaine esterase activity, while acetazolamide blocked hydrolysis of procaine by washed erythrocytes. Kinetic studies in whole blood also identified 2 different enzymes. Procaine esterase activity associated with red blood cells was not impaired in patients with renal failure or hepatic cirrhosis, but procaine half-life (t 1/2) in whole blood of normal subjects was longer after 250 mg acetazolamide.

Acetazolamide↗
PubMed1980

Plasma protein carbamylation and decreased acidic drug protein binding in uremia.

The effects of in vitro carbamylation of plasma with potassium cyanate on drug-protein binding have been investigated. Potassium cyanate added to samples of normal plasma and incubated for 30 to 150 min induced time-related plasma protein carbamylation. Carbamylation of plasma did not influence quinidine protein binding, but resulted in decreased salicylate binding. The increased free fraction of salicylate in plasma correlated with the degree of carbamylation of plasma proteins (r = 0.99; p less than 0.001). Plasma from patients with chronic renal disease showed varying degrees of plasma protein carbamylation, correlating with the values of free plasma salicylate (r = 0.80; p less than 0.05). Scatchard plots for sulfadiazine binding in plasma from patients with uremia and in normal plasma carbamylated in vitro with potassium cyanate showed changes in the 2 groups when compared with those in normal individuals. If cyanate is produced in vivo from urea in patients with uremia, plasma protein carbamylation may play a role in the decreased plasma protein binding of some acidic drugs.

Adult↗
PubMed1979

Image of systemic antimicrobial agents as perceived by physicians in a 900 bed hospital.

A survey among hospital staff physicians was conducted in order to evaluate their attitudes towards systemic antimicrobial agents. Direct questions about the value of different agents and choice within pairs of antimicrobial drugs, stating the reasons for the preference, were included in the questionnaire used. Gentamicin, penicillin G and ampicillin were the most popular antibiotics among respondents. On the other hand, ampicillin, penicillin G, sulfonamides, tetracycline and aminoglycosides were the agents perceived as most often associated with side-effects. Low toxicity, bactericidal effect, diffusion in the body and familiarity with the drug were acknowledged as the most important attributes in choice of a systemic antimicrobial agent, but a broad spectrum of antibacterial activity appeared as a major determinant in the choice of these drugs when physicians were asked to select one substance from members of several pairs listed. The results suggest that certain important misconceptions may have played a substantial role in the prescribing habits of the physicians surveyed.

Anti-Bacterial Agents↗
PubMed1979

Etomidate and plasma esterase activity in man and experimental animals.

No hydrolysis of etomidate in plasma in vitro was detected in samples from man, horse, cow, sheep, guinea pig or white rabbit. Brown rabbits showed a moderate degree of hydrolysis and it was marked in plasma from Wistar rats. In this species, a single enzyme, an alliesterase, participated in the hydrolysis in plasma. Etomidate did not interfere with the hydrolysis of procaine by plasma pseudocholinesterase in man.

Animals↗
PubMed1979

Plasma protein binding of salicylate and quinidine in patients with multiple myeloma.

The plasma protein binding of salicylate, a representative acidic drug, and of quinidine, a representative basic drug, has been studied in patients with multiple myeloma, a disease characterized by a profound alteration of the plasma protein pattern. Abnormal binding of salicylate was detected only in patients with high values of circulating abnormal protein. Plasma protein binding of quinidine was not altered in any of the patients studied.

Adult↗
PubMed1978

Metabolism of procainamide in patients with chronic heart failure, chronic respiratory failure and chronic renal failure.

Fractional hydrolysis and acetylation of procainamide, acetylation of procainamide-derived p-aminobenzoic acid and plasma hydrolysis of procaine were studied in 20 patients with chronic heart failure (CHF), 20 patients with chronic respiratory insufficiency (CRI) and 20 patients with chronic renal failure (RF). The results were compared with those obtained in a group of 20 normal volunteers. Hydrolysis of procainamide and procaine were reduced in patients with CHF and CRI, but not in patients with RF. Moreover, more marked decreases in procainamide and procaine hydrolysis were seen in subgroups with secondary hepatic dysfunction. The diminution of hydrolysis of procainamide was not paralleled by changes in acetylation of procainamide or p-aminobenzoic acid. It is concluded that in patients with hepatic involvement secondary to advanced CHF or CRI, hepatic and plasmatic hydrolysis activity is decreased to a degree equivalent to primary liver failure.

Acetylation↗
PubMed1977

Protein binding of salicylate and quinidine in plasma from patients with renal failure, chronic liver disease and chronic respiratory insufficiency.

The plasma protein binding of a representative acidic drug, salicylate, and a representative basic drug, quinidine, has been studied in patients with several diseases that are sometimes associated with uraemia or a change in serum albumin level. Decreased plasma protein binding of salicylate was observed in plasma from patients with uraemia and liver disease. Low albumin levels in these patients could only account inpart for the decreased binding. On the other hand, salicylate binding to plasma proteins appeared to be increased in patients with hypoxia. Decreased plasma protein binding of quinidine was observed in some patients with uraemia and in the majority of patients with liver disease.

Adult↗
PubMed1977

Metabolism of procainamide and p-aminobenzoic acid in patients with chronic liver disease.

Procainamide acetylation and hydrolysis, procainamide-derived p-amino-benzoic acid acetylation, and plasma hydrolysis of procaine were studied in normal volunteers and in 20 patients with chronic liver disease, Impairment of procainamide acetylation was evident in the patients, but no correlations were demonstrable between the degree of impairment and the severity of the disease. On the other hand, procainamide hydroylsis was diminished in liver disease, and as indicated by depression of serum albumin levels and plasma prothrombin activity this alteration did correlate with the degree of impairment of liver function. Procaine hydrolysis in plasma was also affected, the mean in vitro plasma half-life being prolonged in the patients with liver disease and correlating with the degree of hepatic impairment. A correlation of procainamide hydrolysis with procaine hydrolysis was also observed. Finally, acetylation of procainamide-derived p-aminobenzoic acid appeared to increase in patients with liver disease, the degree of acetylation increasing with decreasing procainamide hydrolysis capacity.

4-Aminobenzoic Acid↗
PubMed1977

Blood and saliva salicylate measurement in the monitoring of salicylate therapy.

Total and free plasma salicylate as well as saliva salicylate was measured in 13 patients with rheumatoid arthritis treated with different doses of acetylsalicylic acid alone. Although the clinical response was judged moderately effective to effective in all cases, total and free plasma salicylate varied markedly. Saliva salicylate correlated well with both total plasma salicylate and fre plasma salicylate. Determination of saliva salicylate may be a simple and useful technique for the monitoring of salicylate therapy.

Adult↗