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Biomedical subjects

G Edwards

Publications and source records attributed to G Edwards.

At least 325 records · Page 18Linked to original sources
PubMed1982

The effect of renal disease on the pharmacokinetics of diethylcarbamazine in man.

1 The pharmacokinetics of diethylcarbamazine (DEC) were studied in twelve patients with chronic renal function impairment. 2 Selected pharmacokinetic parameters, plasma half-life (T1/2), area under the plasma concentration-time curve (AUC), elimination rate constant (Kel) and 24 h urinary excretion were regressed versus parameters indicative of renal function. 3 Significant negative correlations were observed between creatinine clearance and both plasma T1/2 and log10 T1/2. 4 Significant positive correlations were obtained between (a) creatinine clearance and elimination rate constant of DEC and (b) reciprocal serum creatinine and l/T1/2. Creatinine clearance was significantly and positively correlated with 24 h urinary excretion of DEC. 5 No significant correlations were observed between age, sex or weight and renal function but DEC excretion did appear to decrease with increasing urinary pH. 6 Plasma half-life, and area under the plasma concentration-time curve were increased and 24 h urinary excretion of DEC was significantly reduced in patients with chronic renal function impairment, compared with normal volunteer subjects receiving an identical dosage of DEC at acidic urinary pH.

Adult↗
PubMed1982

A computerized study of knee-ligament injuries: repair versus removal of the torn anterior cruciate ligament.

A retrospective review of 202 patients with acute injury to knee ligaments was carried out by chart review, scored questionnaire and scored physical examination. Of 62 patients with complete midsubstance injury to the anterior cruciate ligament, repair was attempted in 46, while 16 had complete excision of the ligament without replacement or augmentation. Computer analysis revealed that these groups were similar with respect to mean age of the patients, sex distribution, incidence of meniscectomy and distribution of associated injuries. At 4-year follow-up, there was no advantage of primary repair over excision for these injuries. In fact, repair seemed to be subjectively and objectively worse than excision, being associated with increased pain and decreased range of motion. The high rate of signs and symptoms of deterioration in both groups suggests a need for better alternatives in the acute phase of anterior cruciate ligament injury.

Adolescent↗
PubMed1981

Diethylcarbamazine disposition in patients with onchocerciasis.

Diethylcarbamazine (DEC), 0.5 mg/kg, was taken orally by six patients being treated for onchocerciasis. Blood samples were taken at timed intervals for 48 hr and urine and feces collected for 4 days. Plasma and urinary concentrations of DEC and DEC N-oxide were measured by gas-liquid chromatography. DEC appeared to be rapidly absorbed, with a peak plasma concentration of 150 to 250 ng/ml reached in 2 to 3 hr. There was a secondary rise in plasma DEC concentration at 5 to 6 hr in all patients. In contrast to the way the drug is eliminated in rats, in man it was by both renal and extrarenal routes, with small amounts (+/- 10%) being excreted as an N-oxide metabolite. DEC kinetics were also investigated in five normal subjects and the result were much the same. Clinical implications are discussed.

Adult↗
PubMed1981

The effect of variations in urinary pH on the pharmacokinetics of diethylcarbamazine.

1 The partitioning of diethylcarbamazine (DEC) between octan-1-ol and aqueous buffer was shown to be dependent upon the pH of the buffer. 2 Buccal absorption of DEC in five subjects was shown to increase with increasing pH. 3 In view of these findings, the disposition of DEC was investigated in the same five subjects following the oral administration of 50 mg DEC citrate on two occasions. 4 The elimination half-life (T1/2) of DEC and the area under the plasma concentration v time curve (AUC) were significantly increased when an alkaline urinary pH was maintained compared with the values of these parameters obtained on a second occasion when an acidic urinary pH was maintained. Renal clearance and total urinary excretion of DEC were significantly less at alkaline urinary pH than under acidic conditions. 5 The clinical significance of these observations is discussed both with respect to dose modification under conditions of changing urinary pH and the possibility of the manipulation of urinary pH in order to produce more effective dosage regimens.

Absorption↗
PubMed1981

Nomenclature and classification of drug- and alcohol-related problems: a WHO Memorandum.

Earlier work in this field is reviewed and present concepts and terminologies are examined in detail. A revised way of dealing with ideas implicit in the terms "drug abuse" or "drug misuse" is proposed; the term "neuroadaptive state" is suggested as an alternative to "physical dependence"; a profile is given of the elements that constitute a "drug dependence syndrome"; and the need to differentiate conceptually between "dependence" and "drug related disability" is stressed. A model of dependence is outlined in which dependence is considered as a psycho-physiological-social syndrome determined and kept going by a complex system of reinforcements. The association between substance use and mental illness is discussed with emphasis on possible two-way relationships. The need for population studies and in particular for longitudinal studies is emphasized. The bearing of all the fore-going considerations on work towards the revision of relevant classification systems is considered, and, in the final section, several recommendations on nomenclature are brought together and suggestions are made for research that might lead to refinement of classification and diagnostic systems.

Alcoholism↗
PubMed1980

Opium and after.

Explore the source record for details and available documents.

Drug and Narcotic Control↗
PubMed1980

The effect of proteolytic enzymes on the disposition of tetracycline.

The acute administration of a mixture of trypsin and chymotrypsin did not significantly affect the rate or extent of disappearance of tetracycline from the rat gut in situ, nor did chronic administration of enteric coated tablets containing trypsin and chymotrypsin to rats significantly influence the rate or extent of absorption of tetracycline compared with rats receiving enteric coated placebo tablets. Similarly, chronic enzyme administration did not effect either the systemic clearance, half life or apparent volume of distribution of intravenously administered tetracycline compared with rats receiving placebo tablets.

Administration, Oral↗
PubMed1979

Drinking problems: putting the Third World on the map.

The extent of alcohol-related problems in developing countries is reviewed, and it shows that alcoholism has a serious impact in these countries. Moreover, the impact has special features, which are discussed. Suggestions for controlling alcoholism in the Third World are made.

Africa↗
PubMed1979

The disposition of cyclophosphamide in a group of myeloma patients.

The disposition of cyclophosphamide and its alkylating metabolites was investigated in a group of myeloma patients with varying degrees of renal function impairment. No correlation between renal function and clearance of cyclophosphamide or its alkylating metabolites was found. No evidence of accumulation of cyclophosphamide or alkylating activity was found in four patients receiving radiolabelled cyclophosphamide. Renal function was found to be related to the reciprocal of the area under curve of alkylating activity, indicating that this area increased as renal function decreased. In view of the large nonrenal component of alkylating activity elimination and the large inter-subject variability, it is recommended that dose of cyclophosphamide is not altered in moderate impairment of renal function.

Alkylating Agents↗
PubMed1979

Intrahepatic mutagenesis assay: a sensitive method for detecting N-nitrosomorpholine and in vivo nitrosation of morpholine.

An intrahepatic host-mediated mutagenicity assay capable of detecting low levels of N-nitrosomorpholine (NMOR) is described. The indicator organism was Salmonella typhimurium TA1530 which had been injected intravenously 10 min prior to the administration of the test compound. The bacteria were subsequently recovered from the liver and scored for revertants by standard methods. The lower limit of detectibility of this system for intubated NMOR was 0.2 microgram/g body weight. This assay was then used to study the formation of NMOR in vivo from morpholine and nitrite which had been sequentially gavaged to mice. Under acidic conditions (pH 3.4) 12--19% of the administered morpholine was converted to NMOR in the presence of excess nitrite. This nitrosation, and the subsequent uptake and activation of the NMOR, took place so rapidly that most of the total mutagenic response was complete within 15 min. This response was inhibited by prior intubation of ascorbic acid, a known inhibitor of nitrosation, and enhanced by sodium thiocyanate, a nitrosation catalyst.

Animals↗