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Biomedical subjects

P K Johnson

Publications and source records attributed to P K Johnson.

At least 19 recordsLinked to original sources
PubMed1994

CNS as unit-based case manager.

Patient satisfaction, patient-perceived quality of life, and nurse satisfaction were compared before and after implementation of nursing case management on a 36-bed medical unit in a southeastern acute care hospital. In this quasi-experimental pre- and postintervention study, 50 adult oncology patients were surveyed. CNSs as unit-based case managers planned, coordinated, and facilitated care that was delivered by registered nurses, licensed practical nurses, and nursing assistants. As measured by the LaMonica/Oberst Patient Satisfaction Tool, patient satisfaction showed a statistically significant increase six months after implementation of nursing case management. Neither job satisfaction of nurses nor patient-perceived quality of life showed significant improvement.

Hospital Units↗
PubMed1991

Nursing care management.

Patient satisfaction, patient-perceived quality of life, and nurse satisfaction were compared before and after the implementation of nursing case management in a southeastern acute care hospital. Immune-compromised oncology patients were sampled as proxy for patients with AIDS. Clinical nurse specialists as case managers planned, coordinated, and facilitated patient care on the 36-bed study unit. Patient satisfaction showed a statistically significant increase 6 months after implementation of nursing case management.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Detection of bacteria by hybridization of rRNA with DNA-latex and immunodetection of hybrids.

A novel nucleic acid hybridization assay with a DNA probe immobilized on 1.25-micron-diameter latex particles was developed. Hybridization of the immobilized probe DNA with sample rRNA was complete in 10 to 15 min. Alkaline phosphatase-labeled anti-DNA-RNA was allowed to bind to the DNA-RNA hybrids on the latex particles. Then the latex was collected on a small glass fiber filter pad, and bound alkaline phosphatase was quantitated by reflectance rate measurement. The method detected a broad range of bacterial species and had a detection limit of 500 cells per assay. The assay was used to screen urine samples for bacteriuria and had a sensitivity of 96.2% compared with conventional culture at a decision level of greater than or equal to 10(4) CFU/ml. The hybridization method could have broad application to the detection of bacteria and viruses.

Bacteria↗
PubMed1986

Homogeneous apoenzyme reactivation immunoassay for thyroxin-binding globulin in serum.

In this automated apoenzyme reactivation immunoassay system (Ames Optimate) for thyroxin-binding globulin (TBG), the sample and N6-aminohexylflavin adenine dinucleotide-labeled TBG react sequentially with antiserum. Then apoglucose oxidase is added to combine with the free fraction and generate glucose oxidase activity, which is measured colorimetrically. The assay requires 100 microL of sample and covers the clinically significant range for TBG (less than 2.5 to 55 mg/L). The first result is obtained in 16 min; assay of 29 samples and their blanks is completed in less than 1 h. The lower limit of detection is about 2.5 mg/L. Between-assay CVs (n = 9) were less than 9%, within-assay CVs (n = 5) were less than 6%, and analytical recovery of TBG was 103-112%. Reagents are stable at 4 degrees C for at least five months. Results by this method for serum TBG (y) compared well with those determined by radioimmunoassay (x): y = 1.029x--0.352 (r = 0.990, n = 49, Syx = 1.165 mg/L). In addition, with 39 other sera the ratio of total thyroxin (by RIA) to TBG compared well with free thyroxin measured by equilibrium dialysis (r = 0.930) and the free thyroxin index (r = 0.970).

Apoenzymes↗
PubMed1986

Homogeneous substrate-labeled fluorescent immunoassay for disopyramide in human serum: semi- and fully automated procedures.

In this immunoassay for disopyramide in serum, to form the label, disopyramide is covalently attached to a fluorogenic enzyme substrate, 7-beta-galactosylcoumarin-3-carboxylic acid, which is nonfluorescent under the conditions of the assay. Hydrolysis, catalyzed by beta-galactosidase, yields a fluorescent product. As a result of competitive protein binding reactions between drug and label for limited antibody binding sites, this fluorescence is proportional to disopyramide concentration. The assay is sensitive to less than 0.5 mg of disopyramide per liter. Results obtained with either the semi-automated procedure (Ames TDA) or the fully automated (Optimate) procedure correlated well with those obtained by liquid chromatography (r = 0.98 and 0.99). For commercial controls containing various concentrations of the drug, the respective coefficients of correlation were 1.00 and 0.99 for the TDA and Optimate procedures. Within-run CVs for the two procedures were less than or equal to 5.1%, overall CVs less than or equal to 6.5%.

Antibody Specificity↗
PubMed1985

Coupling aminohexyl-FAD to proteins with dimethyladipimidate.

We used an efficient method having general applicability to couple N6-aminohexyl-flavin adenine dinucleotide (AHFAD) to several proteins for use in an apoenzyme reactivation immunoassay system (ARIS). AHFAD is first activated with 40-fold molar excess of dimethyladipimidate, excess imidate is removed rapidly by gel filtration, the activated product is incubated with the protein, and the conjugate formed is purified. This labeling technique permits incorporation of a controlled amount of amino-label into a protein, and eliminates the possibility of self-crosslinking, which would reduce the immunoreactivity of the conjugate. Here we demonstrate the utility of such a conjugate in a totally automated ARIS assay for thyroxin-binding globulin (TBG). After a competitive protein-binding reaction, apoglucose oxidase is added to combine with free TBG-AHFAD conjugate and produce active glucose oxidase, which is measured colorimetrically in a peroxidase-linked reaction. The assay covers the clinically significant range for TBG from 0 to 60 mg/L and has a throughput of 60 reactions in 75 min. Comparison with an RIA method (x) by regression analysis yielded the equation y = 0.890x + 1.217 (r = 0.975, n = 47, Syx = 1.906 mg/L).

Apoenzymes↗
PubMed1976

A rapid, flow-through column radioimmunoassay for human chorionic somatomammotropin.

A rapid, flow-through, column, nonequilibrium radioimmunoassay for human chorionic somatomammotropin (HCS) is described. The total incubation time is about 1 hour, and no centrifugation is needed. Reproducibility, sensitivity, specificity, recovery, and parallelism are adequate for clinical utility. Hormone levels in a variety of pregnancy sera assayed by this column method are closely related to results from another more conventional radioimmunoassay method.

Dose-Response Relationship, Drug↗
PubMed1975

Cholagiocarcinoma in a patient previously given thorotrast.

The long-term effects of thorotrast administration include local granulomas, blood cell abnormalities, and cancer. To date, more than 100 cases of liver cancer have been reported in patients previously given this radioactive contrast material, with a latency period of approximately 22 years. We report such a case; the patient not only had a thorotrast-induced cholangiocarcinoma, but also showed striking morphologic changes in the red blood cells secondary to splenic dysfunction.

Adenoma, Bile Duct↗
PubMed1972

Therapy of acute myelocytic leukemia. Daunomycin contrasted with a combination of cytosine arabinoside and 6-thioguanine.

Twenty-three patients with acute myelocytic leukemia (aml) were treated with daunomycin and the results contrasted to those obtained in a subsequent group of 18 patients treated with cytosine arabinoside (ara-c) and 6-thioguanine (tg). The complete remission (cr) rate with daunomycin was 17 percent (mean duration 10.6 months) and the partial remission (pr) rate 26 percent (mean duration 44 days). Corresponding figures in the ara-c and tg group were: cr rate 44 percent (mean duration 5.8 months) and pr rate 17 percent (mean duration 48 days). There were 12 deaths resulting from daunomycin-induced pancytopenia and in ten of the patients who died persistent leukemia infiltrate was found in antemortem marrow specimens or at autopsy. This contrasts with death of six patients from ara-c and tg-induced pancytopenia, in four of whom residual leukemic infiltrate was not evident. Daunomycin alone is deemed not suitable for induction of remission in aml. The results obtained with ara-c and tg are encouraging and may be improved if the number of infectious deaths associated with drug-induced pancytopenia can be reduced.

Acute Disease↗