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Biomedical subjects

D M Taylor

Publications and source records attributed to D M Taylor.

At least 217 records · Page 12Linked to original sources
PubMed1980

The mechanism of 67Ga uptake in animal and human tumours.

The subcellular distribution of 67Ga has been studied by differential centrifugation in 3 transplantable mouse tumours, 3 transplantable rat tumours, 1 dog tumour, 3 human tumour xenografts and 2 human tumours in situ at various times after injection of the citrate complex. From 24 h post injection of nuclide was located predominantly in lysosomal structures in all the tumours studied. Studies in two murine tumours showed marked differences in the rate of lysosomal accumulation of 67Ga. In the ADJ/PC6 plasmacytoma lysosomal uptake of 67Ga had reached a plateau within 15 min while in the S180 tumour lysosomal accumulation of the nuclide occurred over the first 24 h. Normal mouse liver showed a similar pattern to this latter tumour. It is postulated that these variations in the rate of lysosomal accumulation of 67Ga reflect differences in the permeability of the lysosomal membrane. While large amounts of 67Ga were found in the crude nuclear fraction of some tumours this was attributed to unbroken cells as studies with purified nuclei from 7 different tumours indicated that between 2 and 14% of the total tumour 67Ga was associated with the nuclei.

Animals↗
PubMed1980

Reconstructive keratoplasty in the management of conditions leading to corneal destruction.

Progressive corneal destruction of varying causes can result in pathologic changes that are incompatible with globe survival. Reconstructive keratoplasty and scleroplasty, in combination with other procedures, can be attempted as an alternative to enucleation, evisceration or spontaneous phthisis bulbi. The results of 50 reconstructive keratoplasties in 36 patients with severe corneal destruction are presented with one- to twenty-two year follow-up. Ninety-nine percent of the eyes were salvaged, 69% have clear grafts, 86% are visually improved and 51% achieved acuity of 20/100 or better.

Adolescent↗
PubMed1980

An infected eczematous condition in mice: methods of treatment.

Eczematous lesions in VM mice were invariably infected with Staphylococcus pyogenes aureus. A variety of preparations was used in treatment and although most were ineffective, one combining steroid and antibiotic therapy achieved remarkable results.

Animals↗
PubMed1980

The effect of the administration of iron on gallium 67 citrate uptake in tumours.

Consideration has been given to the use of iron as an aid in 67Ga scanning. The effects of various doses and the time of injection have been measured quantitatively in four transplantable rodent tumours. It was found most effective to administer the iron, as ferric ammonium citrate, before the 67Ga injection. The experimental tumours respond to different extents, and the tumour:non-tumour ratios at four hours after 67Ga injection have been found to be from two to four times better than those obtained at 24 hours with 67Ga alone. The effects of administered iron on the rate of blood clearance and the plasma binding of 67Ga have been measured. The use of carrier gallium or scandium was found to be less advantageous than the use of iron.

Animals↗
PubMed1979

The role of lysosomal enzyme activity in the localization of 67 gallium citrate.

The distribution of 67Ga citrate at 24 h post injection has been studied in the normal tissues of the mouse, rat and dog; 13 transplantable mouse tumours and 7 rat tumours have also been examined. The total activities of four lysosomal enzymes, aryl sulphatase, beta-glucuronidase, acid phosphatase and cathepsin-D were measured as well as the incorporation of thymidine-3H and leucine-14C ad indicators of DNA and protein synthesis. The results show a close correlation between 67Ga uptake and lysosomal enzyme activity in the tumours studied, which is an extension of the same relationship for normal tissues. It is suggested that the reported correlation between the uptake of 67Ga and the rate of cellular proliferation is secondary to the primary function of the lysosome in the localisation of the nuclide, lysosomal enzyme activity also being enhanced in situations of increased metabolic activity. A similar relationship appears to occur following administration of 111IN-Bleomycin and 99mTc-Citrate.

Acid Phosphatase↗
PubMed1979

The mechanism of the localization of 67gallium citrate in experimental abscesses.

67Ga accumulation in turpentine-induced abscesses, from 5 h to 20 days old, in the rat has been investigated, and the results indicate that this is dependent on polymorphonuclear leukocyte (PMN) infiltration of the inflamed site. 67Ga concentration 24 h after injection correlates well with the activities of the lysosomal enzymes, aryl sulphatase and beta-glucuronidase, P less than 0.001, and with the DNA content of the tissue. There is no direct relationship with the rate of DNA synthesis. The mechanism of lysosomal incorporation into PMNs is consistent with the factors involved in 67Ga uptake into tumours and normal tissues.

Abscess↗
PubMed1979

The urinary excretion of gallium-67 citrate in patients with neoplastic disease.

The urinary excretion of gallium-67 has been studied in twenty-nine patients with considerable variation, ranging from 2.71 to 35.21 per cent of the injected dose in the first twenty-four hours. The data was analyzed to determine whether differences in excretion could be related to sex, age, plasma level, site or extent of disease but no significant relation could be found. While chemotherapy or radiotherapy has been shown to affect both the plasma clearance and protein binding they have no influence upon the urinary excretion of the isotope in this study. This study shows that all patients with high urinary excretion had bone metastasis from various types of primary tumour. Not all patients with bone metastasis have high urinary excretion of gallium-67. It would appear, however, from our limited series that patients with bone metastasis and normal urinary excretion of gallium-67 show a good response to treatment.

Adult↗
PubMed1979

The stability and distribution of Tc-HIDA in vivo and in vitro.

Tc-HIDA is a promising new agent for imaging the biliary system. In this study radiochromatography on paper or Sephadex G25 gel has been used to measure the proportions of TcHIDA, 'hydrolysed Tc' and pertechnetate in solutions from a commercial kit (CIS TCK 15) and in body fluids from patients and rats receiving this radiopharmaceutical. The tissue distribution in male and female rats has shown the radiopharmaceutical to be rapidly removed from the blood by the liver and then excreted via the intestines. There appears to be a sex difference in the uptake in the kidneys and in the urinary excretion in both rats and patients.

Animals↗
PubMed1979

Isolation and characterization of recombinant DNA plasmids carrying Drosophila tRNA genes.

Recombinant plasmids carrying Drosophila melanogaster tRNA genes were constructed by ligation of HindIII-cleaved Drosophila DNA to HindIII cut pBR322 DNA. 90 clones were isolated that contained genes for one or more of eleven tRNAs. 43 of the plasmids were characterized by a number of methods: restriction nuclease digestion; agarose gel electrophoresis; hybridization with individual, purified, 125I-labelled Drosophila tRNA molecules and in situ hybridization to Drosophila chromosomes. The results show that several different tRNA genes have been isolated which code for single, specific isoacceptors. The DNAs from 8 plasmids each hybridize to single sites on Drosophila polytene chromosomes. In addition, the data show examples of two different plasmids hybridizing to different loci coding for the same tRNA; this means that we have isolated representatives of tRNA genes which map at widely separated points on the Drosophila genome.

Animals↗
PubMed1979

Keratoplasty and intraocular lenses: current status.

Present methods of treating combined corneal disease and cataracts in elderly patients are unsatisfactory, and multiple operative procedures may be required. From 1975 through 1978, 60 attempts were made to restore relatively normal optics and achieve rapid visual recovery with a single operative procedure consisting of keratoplasty, cataract extraction, and intraocular lens insertion in various combinations. As of this writing, there have been few complications, and 82% of the grafts are clear.

Aged↗