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Biomedical subjects

J K Butler

Publications and source records attributed to J K Butler.

6 recordsLinked to original sources
PubMed1979

Bioavailability and pharmacokinetics of norethisterone in women after oral doses of ethynodiol diacetate.

Measurement by radioimmunoassay of plasma norethisterone (NE) has been used to compare the bioavailability of tablets containing ethynodiol diacetate (EDA) with that of a standard oral solution of this progestogen in 12 normal women. The tablets investigated were from three batches which showed different in vitro dissolution rates. There were no significant differences in the bioavailability of the tablet formulations, which were essentially bioequivalent to the solution. Peak blood levels of NE were reached within 4h of EDA administration in solution or tablets. After the peak, NE plasma levels declined in two phases, with a mean terminal elimination half lives of 4 to 6.9h. The pharmacokinetics of NE after EDA administration showed some similarity to those observed by other workers after oral doses of NE itself.

Adult↗
PubMed1979

Methods for improved light microscope microtomy.

Experiments undertaken to improve the ease and quality of preparing tissue for light microscopy have resulted in methods for routine production of high quality serial paraffin and glycol methacrylate sections in the 1 to 4 micrometer range using a standard rotary microtome. These methods involve sectioning with mechanically-broken Ralph-type knives, inspected for quality before mounting with double-stick tape on a holder-fluid trough in which the ribbon floats over an immersed slide and sections are mounted by lowering the fluid level in the trough. Specimen return stroke retraction, necessary for quality sectioning of plastic or with a fluid trough, is inexpensively provided by an attachable specimen holder that fits into the rotary microtome's chuck and, actuated by the microtome mechanisms, retracts the specimen during each return stroke. Descriptions of four instruments: a mechanical breaker for Ralph knives, a knife edge inspection device, an attachable specimen retractor for rotary microtomes, and a section collecting-mounting device as well as details of their use are included. Differences in cutting speed and cutting cycle cadence critical to quality sectioning with different embedments are detailed. Factors important in choosing the best embedment and most appropriate section thickness as well as choosing between dry or wet sectioning methods are also considered.

Fixatives↗
PubMed1978

Is it ethical to conduct volunteer studies within the pharmaceutical industry?

There is a case for appropriately selected drug studies within the pharmaceutical industry in which employee volunteers are used. Provided the organisation and conduct of such studies are approached in an ethical manner, with attention to safe-guarding the volunteer and recognising the limitations, this work can be done expeditiously, cheaply, and safely. Some details are given of the arrangements made for volunteer studies within a company.

Adolescent↗
PubMed1977

Ethical review in the pharmaceutical industry.

1. There seems no reason why clinical pharmacology studies conducted within the pharmaceutical industry should be exempt from the requirement of ethical review, and independent review in this situation reduces the vulnerability of the company and its employees, in addition to serving its primary function of protecting the volunteer subjects. 2. Experience within one company has shown that independent ethical review need not seriously influence the pace of research. 3. It is important that such committees should be seen to be independent and competent.

Drug Evaluation↗
PubMed1976

An illuminator for ultramicrotome knife orientation and block approach.

The construction and operation of a simple, inexpensive illuminator that produces high quality illumination of the ultramicrotome knife edge and the edge to block face gap resembling dark field is described. Use of the illuminator greatly speeds knife adjustment and reduces the likelihood of specimen or knife edge damage. The illuminator uses a grain-of-wheat light bulb and an adjustable bulb holder fashioned from bent paper clips. The holder permits both lateral and axial adjustment of the bulb position, which is necessary to achieve satisfactory illumination with different specimens and knives. The illuminator, with slight modification, can be adapted for use on any ultramicrotome.

Lighting↗