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Biomedical subjects

K Olson

Publications and source records attributed to K Olson.

At least 91 records · Page 5Linked to original sources

Methotrexate compared with placebo in lung cancer.

Two hundred thirty-nine patients with microscopically proven, inoperable bronchogenic carcinoma were allocated at random to receive twice weekly I.M. injections of either methotrexate at "high dose" of 0.06 mg/kg/dose or methotrexate at "low dose" of 0.2 mg/kg or visually indistinguishable placebo in the same volume of 0.1 ml/kg for four months. Twelve patients were invalidated for procedural reasons. Objective response (greater than or equal to 50% tumor regression) was dose-related with 21% of 48 patients with measurable disease on high -ose, 11% of 37 patients on low dose, and 6% of 32 patients on placebo. Corresponding response rates for epidermoid carcinoma were 35% of 23 patients, 9% of 11 patients, and 0 of 13 patients. Responders in the two treatment groups had a three to four fold increase of median survival (p less than .05). Non-responders on high and low dose methotrexate lived as long as patients on placebo. Leukopenic patients in all three treatment groups lived substantially longer than patients without leukopenia less than 4,500/mm3, irrespective of presence or absence of objective response. All three regimens were well tolerated. None of the patients had life-threatening toxicity. It is concluded that methotrexate at "high dose" is a potentially useful drug for temporary palliation of epidermoid carcinoma of the lung.

Adenocarcinoma↗

Intracavitary bleomycin in the management of malignant effusions.

Instilled bleomycin and thoracostomy were utilized in 38 patients with malignant pleural effusions; the therapy produced a complete or partial response rate of 63%. Toxicity was minimal. In patients with intraperitoneal effusions, bleomycin instillation after drainage produced a complete or partial response in 36%. One patient had severe hypotension and fever. Patients with ovarian and breast carcinoma responded best, among them, effusions were controlled in greater that 70%. Because of its low systemic toxicity, absence of marrow toxicity, and virtual absence of discomfort, we think that the local instillation of bleomycin is indicated in the management of malignant effusions.

Ascites↗

Enzymatic multiplication of a chemically synthesized DNA fragment.

A synthetic DNA fragment of 19 residues was enlarged by the enzymatic addition of deoxyadenylate residues to its 3'-end with calf thymus terminal deoxynucleotidyl transferase. The 3'-terminus of this elongated DNA strand was blocked with 2', 3'-dideoxyadenylate to prevent hydrolysis by the 3'-exonuclease function of E. coli DNA polymerase I. This elongated and 3'-blocked fragment was annealed to an oligomeric primer and used as a template for the synthesis of a complementary copy of the synthetic 19-mer. The product of such a repair synthesis was separated by gel filtration and analyzed by nearest neighbor techniques. All template strands were copied with complete repair in over 90% of the chains. Facile recovery of the elongated template by virtue of its size permitted repetition of the copy process, thus allowing accumulation of the desired strand.

Animals↗

Determination of the 3' terminal nucleotide of DNA fragments.

A new method for determining the 3'-terminal nucleotide of a DNA strand is presented. Use is made of the fact that one (and only one) 2',3'-dideoxyribonucleotide can be added to the 3'-end of a DNA fragment with calf thymus terminal transferase. Addition of more than one nucleotide analog per strand is impossible due to the absence of a 3'-terminal hydroxyl group. If the terminatind dideoxyribonucleotide contains an (alpha 32p) label, the resulting 3'-blocked strand can be digested by "nearest neighbor" techniques and the original 3'-endgroup determined. Picomole quantities of DNA strands can be labeled and the 3'-end determined.

Animals↗

Differential reinforcement and signal detection.

Reinforcement was introduced for responses normally treated as errors in signal-detection procedures. The first experiment used a standard two-response discrete-trial procedure with no reinforcement for errors. Results showed that rats altered their response biases but maintained constant sensitivity to visual signals when reinforcement probabilities varied, and that their sensitivity depended on the physical difference between signals, in accordance with the predictions of signal-detection theory. Experiment II, with rats, and Experiment III, with pigeons, demonstrated that sensitivity decreased in this procedure when reinforcement was scheduled for errors with the signals held constant, despite independence of overall number of reinforcers and sensitivity. Experiment IV, with rats, replicated the decrease in sensitivity in a continuous procedure employing only one response. The decrements in sensitivity were similar across Experiments II, III, and IV, and accorded well with earlier research. Thus, contrary to a fundamental assumption of signal-detection theory, estimates of sensitivity are not always invariant with respect to the outcomes of responding, but depend on relative reinforcement of correct responses.

Animals↗

Impact of computerized quality of life screening on physician behaviour and patient satisfaction in lung cancer outpatients.

The purpose of this paper was to determine if providing patient specific Quality of Life (QL) information to clinic staff before a clinic appointment improved patient care in a lung cancer outpatient clinic. Patients were sequentially assigned to either a usual care control group or the experimental group, which completed a computerized version of the European Organization for Research and Treatment of Cancer (EORTC) QLQ-C30 questionnaire in order to provide the clinic staff with QL information prior to the clinic appointment. The control group completed the EORTC QLQ-C30 paper version after the clinic appointment. Outcome measures were patient satisfaction, the degree to which issues identified on the QL questionnaire were addressed in the appointment, and a chart audit, which measured charting of QL issues and actions taken by the clincian relating to QL. In the experimental group, more QL issues identified by the patient on the EORTC QLQ-C30 were addressed during the clinic appointment than in the control group. As well, marginally more categories were charted and a trend towards more actions being taken was seen in the experimental group. Patients reported being equally and highly satisfied with the treatment in both groups. The clinical implication is that the computerized administration of the EORTC QLQ-C30 questionnaire and providing staff with a report highlighting patient-specific QL deficits is a simple, time-effective and acceptable means of improving patient-provider communication in a busy outpatient clinic. Large trials studying its effectiveness in different patient populations and regions would further elucidate the nature of this effect and potentially improve the overall quality of care that patients receive.

Aged↗

Factors influencing serum levels of carbamazepine and carbamazepine-10,11-epoxide in children.

Carbamazepine-10,11-epoxide (CBZ-E), the principal metabolite of carbamazepine (CBZ), is reported to have antiepileptic and toxic effects similar to CBZ. Steady-state CBZ and CBZ-E levels (high performance liquid chromatography, HPLC assay) were reviewed in 225 outpatient children and young adults taking CBZ with or without other antiepileptic drugs (AEDs). In patients on CBZ alone, mean serum concentration of CBZ was 7.9 +/- 1.9 micrograms/ml and of CBZ-E was 1.5 +/- 0.6 micrograms/ml. The CBZ-E/CBZ ratio was 19.6 +/- 2.4%. Serum CBZ increased with increasing age and with CBZ dose. CBZ-E increased with increasing CBZ dose but was unaffected by age. The CBZ-E/CBZ ratio progressively declined with age. Co-medication with barbiturates or valproic acid significantly increased CBZ-E. Phenytoin showed a similar trend while ethosuximide caused the least change. Patients on CBZ and two or more other AEDs had highest CBZ-E levels and CBZ-E/CBZ ratio. CBZ and CBZ-E levels are variably affected by age, CBZ dose, and co-medication with other AEDs. When other AEDs are administered, careful monitoring is especially indicated in order to avoid toxicity.

Adolescent↗

Focusing on research.

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Cost-Benefit Analysis↗