Search PubMed⌕ Search

Biomedical subjects

R D Strickland

Publications and source records attributed to R D Strickland.

7 recordsLinked to original sources
PubMed1979

Abnormal enzyme phenotype (E1a E1f): normal response to succinylcholine.

The enzyme serum cholinesterase responsible for the hydrolysis of the muscle relaxant succinylcholine exists in the form of several variants. These may be identified in serum by using substances which inhibit their activity to different degrees. The heterozygote for the atypical and fluoride resistant enzymes (E1a E1f) is one of the phenotypes which has been reported to be sinsitive to succinylcholine. A case is described where succinylcholine given on two separate occasions did not induce apnoea in an individual phenotyped as E1a E1f by at least five methods of inhibition. This is the first reported example of such insensitivity to the drug in this phenotype. Temperature activities for the patient's serum over the range of 20 degrees C to 45 degrees C differed from that of an established E1a E1f phenotype used as a control. There was a progressive inactivation of the control serum at temperatures higher than 35 degrees C, as previously reported for this phenotype. Activity in the serum of the subject of this study did not exhibit the peak activity at 35 degrees C but continued to rise and probably reached a peak between 40 degrees C and 45 degrees C. The significance of these results in the context of current methods of phenotyping is discussed.

Adolescent↗
PubMed1979

Lipoidal bladder concretion: an unusual autopsy finding in acute lymphoblastic leukemia.

The occurrence of a large (2.3 gm.), wax-like, creamy white concretion in the bladder of a 7-year-old girl who died of acute lymphoblastic leukemia is reported. Lipids constituted 40% of the total weight and triglycerides accounted for 95% of the total lipids. The fatty acid composition of the individual lipid classes showed a predominance of saturated fatty acids (75 to 80%). Factors influencing the pathogenesis of the material are discussed. A review of the literature on childhood leukemia showed no reference to such lipid abnormalities and the occurrence of this type of concretion has not been reported previously.

Child, Preschool↗
PubMed1977

Subsensitivity of beta responses during therapy with a long-acting beta-2 preparation.

The question whether some tolerance or subsensitivity of various beta receptors develops during therapy with long-acting oral beta-2 agents has practical and theoretical importance. We applied a strong beta-2 stimulus (terbutaline, 5.0 mg orally) at weekly intervals for up to three weeks in 19 stable asthmatics and bronchitics while commencing 5.0 mg terbutaline three times daily. The evening dose was omitted before each morning challenge. Challenges were continued at one and two weeks off terbutaline in some patients to test return of beta function. Patients received no ephedrine for two weeks before the study but were allowed aminophylline or isoproterenol inhalations up to 18 and 4 hr before challenges, respectively. Pulmonary function, pulse, and blood pressure were monitored at 0, 60, 120, and 180 min, and metabolic parameters measured at 0 and 180 min. There was significant drug tolerance in the drop and minimum diastolic pressure reached, rise in lactate, cyclic AMP, and blood glucose, and drop in eosinophils. Peak FEV1 and V50 dropped slightly, but vital capacity and minimal airway resistance did not change significantly. During continuous therapy this slight bronchial subsensitivity is probably obscured by elevated baseline function. It might assume importance during periods of excessive inhaler use or abrupt drug withdrawal.

Asthma↗
PubMed1977

Biological activity of dilute isoproterenol solution stored for long periods in plastic bags.

The effect of long-term storage in polyvinyl chloride bags on the biological activity and the chemical stability of isoproterenol was studied. A freshly prepared solution of isoproterenol, isoproterenol solution stored for six months and isoproterenol stored for 30 months were infused into the coronary circulation of 14 isolated rabbit hearts; heart rates were determined. Spectrophotometric studies to determine stability at various pH levels were also done. Aging of the solutions at pH 4 and at a concentration of 4 microgram/ml caused no significant impairment of their potency. Solutions above pH 6 were unstable.

Animals↗
PubMed1977

Apparent theophylline half-life fluctuations during treatment of acute left ventricular failure.

The administration of theophylline in a 63-year-old man with arteriosclerotic heart disease and chronic bronchitis is discussed to illustrate the pharmacokinetics of theophylline in an abnormal host state. The case demonstrates that clearly acute congestive heart failure and its treatment may dramatically affect the kinetics of theophylline elimination. Possible explanations for this phenomenon are presented, and the therapeutic implications are discussed.

Administration, Oral↗