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Biomedical subjects

H Pirkle

Publications and source records attributed to H Pirkle.

30 records · Page 2Linked to original sources

Prothrombin time after heparin removal. Application to monitoring simultaneous anticoagulation with heparin and coumarins.

Coumarin-anticoagulated plasmas from 31 subjects comprising two study groups were passed through epichlorohydrin triethanolamine cellulose (ECTEOLA) chromatography columns. Group I plasmas, which were run with nothing added, had mean prothrombin times of 21.6 +/- 5.4 sec prior to and 22.4 +/- 5.6 sec following exposure to these columns (r = 0.9449; t = 1.8307, P less than 0.100). The mean prothrombin time for Group II, 18.2 +/- 4.9 sec, lengthened with 5 u/ml heparin to 35.5 +/- 16.2 sec, and returned to 19.2 +/- 5.0 (r = 0.9763) after chromatography. Therefore, it appears that coumarin anticoagulation had no significant influence upon the capacity of ECTEOLA effectively to remove heparin in therapeutic doses. This means that virtually all prothrombin time reagent systems can be employed to monitor concurrent heparin and coumarin anticoagulation. In addition, quality control of the combined technic is simpler, and the technic more sensitive to low levels of fibrinogen and factor V.

Cellulose↗

Hepatocellular carcinoma in young, mentally retarded HBsAg carriers without cirrhosis.

In a Californian institution for the mentally retarded, surveillance by autopsy of all deaths (n = 138) identified three cases of hepatocellular carcinoma. Hepatocellular carcinoma cases occurred in young (mean age = 26 years) male carriers of HBsAg and were not associated with cirrhosis. They were of the nonfibrolamellar oncocytic type and were rapidly fatal. Hepatocellular carcinoma incidence in HBsAg carriers was estimated to be 246 times greater than United States males.

Adult↗

Serum propoxyphene concentrations in a cohort of opiate addicts on long-term propoxyphene maintenance therapy. Evidence for drug tolerance in humans.

Propoxyphene, norpropoxyphene, and cyclic dinorpropoxyphene concentrations in the sera of eight opiate addicts were measured by gas chromatography. The addicts were enrolled in a propoxyphene maintenance program and had received 800-1600 mg of propoxyphene napsylate daily for 13-50 months. Serum propoxyphene and norpropoxyphene ranged from 127 to 1070 ng/mL and 814 to 2638 ng/mL, respectively, and their ratio ranged from 0.1 to 0.4. A roughly linear dose-to-serum-concentration relationship was found for serum propoxyphene and norpropoxyphene in the cohort. Cyclic dinorpropoxyphene was detected in three of the subjects' sera. Because tolerance to propoxyphene occurs, knowledge of prior drug exposure is necessary to determine whether an elevated propoxyphene or norpropoxyphene concentration is toxic to patients or decedents with apparent propoxyphene overdose. Serum norpropoxyphene concentration exceeds that of propoxyphene following chronic propoxyphene use. Measurable cyclic dinorpropoxyphene implies chronic propoxyphene use but its absence does not exclude chronic use.

Adult↗

Quantitation of pentobarbital in serum by enzyme immunoassay.

Pentobarbital was quantitated in serum by a homogeneous enzyme immunoassay (EMIT), and the method evaluated for accuracy and precision. A comparison was performed against the authors' modified Goldbaum ultraviolet spectrophotometric procedure. The analytical sensitivity was 2 micrograms/mL with a linearity to 10 micrograms/mL and a coefficient of variation of 6.24%. Linear regression analysis revealed a correlation coefficient of 0.977, a slope of 1.05, and an intercept of -0.07. The t test demonstrated no difference between the two methods at a level of P less than 0.01. The enzyme immunoassay also had the advantages of speed and small sample requirement.

Barbiturates↗