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Biomedical subjects

D M Taylor

Publications and source records attributed to D M Taylor.

At least 199 records · Page 11Linked to original sources
PubMed1984

Evaluation of the safety of metoclopramide in patients with gastroesophageal reflux disease.

The long-term safety of metoclopramide was evaluated for up to 30 months in 269 patients with chronic symptoms of gastroesophageal reflux disease. The usual dosage of metoclopramide was 10 mg four times a day, before meals and at bedtime. No serious side effects were encountered, and the results of laboratory tests performed at frequent intervals were favorable. Audiometric, ophthalmological, and electrocardiographic evaluations showed no drug-related changes.

Adult↗
PubMed1983

Role of transferrin in uptake of non-physiological metals into cells.

At physiological concentrations of citrate the uptake of 59Fe, 67Ga, and 239Pu into human type B lymphocytes of splenic origin is the same in viable and in non-viable cells. Addition of transferrin has no effect on the uptake into non-viable cells but in viable cells it increases the uptake of Fe and Ga but decreases that of Pu. Uptake decreases as transferrin concentration increases although this is less marked with Ga.

Biological Transport, Active↗
PubMed1983

Disinfection studies with two strains of mouse-passaged scrapie agent. Guidelines for Creutzfeldt-Jakob and related agents.

A variety of disinfection procedures were tested on two strains of scrapie agent, treated either as brain macerates (autoclaving) or as 10% homogenates (chemical treatments). It is suggested that a given treatment should produce a titre loss, of both strains of scrapie, of at least 10(4) units before it be regarded as useful for the disinfection of the agents of scrapie and Creutzfeldt-Jakob disease (CJD). By this criterion, treatment at room temperature with about 4% Hycolin (0.6% chlorinated phenols), 0.2% permanganate, 5% Tego (dodecyl-di(aminoethyl)-glycine) or 5% sodium dodecyl sulphate (SDS) are unsuitable. However, data indicate that SDS might be used to reduce the heat stability of scrapie agent. Hypochlorite (Sterilex) was the only satisfactory chemical reagent tested. At least 10(4)-10(5) units of infectivity were lost by treatment with hypochlorite containing 1,000 ppm available chlorine after a 4-16 h exposure, or containing 10,000 ppm available chlorine after a half-hour exposure. The latter result points to the use of concentrated hypochlorite (about 2% available chlorine; approximately 20% Sterilex) to decontaminate surfaces. We suggest that the cleaning action of SDS, or other strong detergents, might also help to decontaminate surfaces, but studies on this are needed. Autoclaving at 126 degrees C for 1-2 h reduced titres by 10(3)-10(7) units, depending on the strain of agent. However, total disinfection of brain containing high titres of infectivity was approached only at 136 degrees C when titre losses of about 10(6) units were obtained by autoclaving for 4-32 min. Further studies are needed before we can make simple, general recommendations for the disinfection of CJD agents in hospital practice.

Animals↗
PubMed1983

Pseudophakic bullous keratopathy.

Pseudophakic bullous keratopathy (PBK) is a relatively new disease that is rapidly becoming the prime indication for penetrating keratoplasty. From 1977 thru 1981 we performed 81 corneal transplants on 66 eyes for this condition. In our experience, the incidence of PBK, with iris-supported lenses, is five times greater than aphakic bullous keratopathy (ABK). A series of 800 intracapsular cataract extractions (ICCE) with implantation of iris-supported lenses (1975-1979) were reviewed. Thirty-four patients (4.3%) developed PBK (average two years after surgery). In a series of 3,000 simple ICCEs (1955-1980), 24 patients (0.8%) developed ABK. Etiologic factors, methods of prevention, and the results of penetrating keratoplasty are considered. PBK following ICCE is a serious disease entity, usually of multifactorial origin. Though 88% of the patients have clear grafts, a high incidence of associated posterior segment disease tends to nullify the visual result. Planned extracapsular cataract extraction and posterior chamber lens insertion (1979-1982) has reduced our incidence of PBK to 0.3% (1/300). These results are promising but premature.

Aged↗
PubMed1983

Identification of transferrin as the principal plutonium-binding protein in the blood serum and liver cytosol of rats: immunological and chromatographic studies.

An analysis of 239Pu-labelled protein complexes in serum and liver cytosol fractions prepared from rats injected intravenously with 239Pu-citrate indicated that among the possible metal-binding proteins, ferritin, transferrin and metallothionein, 239Pu was bound almost exclusively to transferrin. The method employed for the quantitative determination of 239Pu-transferrin was chromatography on immobilized rabbit anti-rat apo-transferrin. There was no evidence that transferrins from serum and liver cytosol are serologically different. The residual blood content of perfused and non-perfused liver was measured using 51Cr-labelled red blood cells and the amounts of blood-derived 239Pu and 239Pu-transferrin in the liver cytosol were calculated. The results are discussed with respect to the possible role of transferrin in the uptake of Pu into cells.

Animals↗
PubMed1983

The metabolism of radiohafnium in rats and hamsters: a possible analog of plutonium for metabolic studies.

The metabolism of radiohafnium (175Hf + 181Hf) was studied in male Sprague-Dawley rats and Chinese hamsters for periods of up to 168 days. The results were compared with similar data for 239Pu in the same rat strain. In rats and hamsters the radiohafnium organ distribution was skeleton greater than skin greater than muscle greater than liver at about 7 days postinjection. Retention of radiohafnium and plutonium was similar in plasma and liver, as were the retention times observed for other organs: Absorption of radiohafnium from the gastrointestinal tract of rats was less than 0.05%. Biochemical studies showed that the radiohafnium was bound mainly to the iron-transport protein, transferrin, in blood plasma and in the liver cytosol of both the rat and the hamster, as has been observed also for plutonium. The metabolic behavior of radiohafnium mimics, to a large extent, that of plutonium, and it is suggested that radiohafnium can serve as a non-alpha-particle-emitting analog of plutonium for metabolic, biochemical, and selected human investigations.

Animals↗
PubMed1982

The structures of genes hybridizing with tRNA4Val from Drosophila melanogaster.

Segments of cloned Drosophila DNA from four recombinant plasmids that hybridize with tRNA4Val have been sequenced. The segments from pDt92R and pDt120R that hybridize to 90C on the third polytene chromosome appear to be either repeats or alleles. They contain one structural gene each of identical sequence but differ at eight sites in 506 base pairs. The structural genes differ at four sites from the sequence expected from that of tRNA4Val. A third plasmid, pDt14, which hybridizes to 89BC on the third chromosome, also contains a structural gene with the same sequence as those in pDt92R and pDt120R. In addition, pDt14 has a gene for tRNA2Phe 214 base pairs upstream and with the same polarity as the tRNA4Val gene. The tRNA2Phe gene contains a 23-base pair segment identical with the corresponding segment in the tRNA4Val genes except for one base pair. The fourth plasmid investigated, pDt55, hybridizes to 70BC. It contains two tRNA4Val genes 525 base pairs apart with opposite polarity. These genes have identical sequences, which corresponds to that expected from the sequence of tRNA4Val. There is no evidence that the first three tRNA4Val genes are expressed at any stage during the development of Drosophila.

Animals↗
PubMed1982

The effects of dimercaptosuccinic acid and other chelating agents on the retention of platinum in the rat kidney after treatment with cisplatin.

The ability of three chelating agents, dimercaptopropanesulphonate (DMPS), dimercaptosuccinic acid (DMSA), and diethylenetriaminepentaacetic acid (DPTA), to reduce the retention of platinum in the kidneys was tested in male Sprague-Dawley rats treated 24 h previously with Cisplatin. DMPS and DMSA, when given as four daily doses of 1 mMol/kg, increased the urinary excretion from 10.1% +/- 1.2% to 13.6% +/- 1.3% and 13.5% +/- 2.6%, respectively, but only DMSA caused a small but significant reduction in the kidney platinum content. DTPA was totally ineffective. It is concluded that none of these agents is likely to be useful for the reduction of Cisplatin-induced renal toxicity in the clinical situation.

Animals↗
PubMed1982

False negative hyperglucosuria test-strip reactions in laboratory mice.

Inhibition of a variety of commercial test strips for hyperglucosuria was experienced in laboratory mice. All mouse strains tested were found to have sufficiently high levels of ascorbic acid to cause inhibition, and male levels were higher than those of females. A regime to obtain optimum detection of positive results is discussed.

2,6-Dichloroindophenol↗
PubMed1982

The localization of metallic radionuclides in abscesses in rats.

The accumulation of ten metals in turpentine-induced abscesses of different ages has been studied in rats. The maximum metal concentration ratio between the abscesses and the non-inflamed contralateral muscle was greater than 1 for all the metals studied, the lowest being 2.5 for Zn, and the highest 36 for Th. The ratio remains greater than 1 for more than 28 days for all metals except Ga. There is a marked increase of beta-glucuronidase activity in the inflamed tissue which correlates well with the metal concentration. In contrast the acid phosphatase activity was reduced for the first few days after turpentine injection and never rose above the normal muscle activity. The metals showing the highest uptake in the inflamed lesion appear to be those which are transported in the blood as a transferrin complex.

Abscess↗
PubMed1981

Structural analysis of fibronectin with monoclonal antibodies.

The reactivity of six monoclonal antibodies with fragments of fibronectin produced with trypsin, chymotrypsin, and Staphylococcus aureaus V8 protease is described. All these antibodies reacted with fragments derived from the C-terminal one-third of fibronectin. This region probably contains sites for the binding of fibronectin to cells, and to heparin and may also contain active sites for the reattachment, spreading, and alignment of transformed cells. Analysis of the reactivities of different sets of proteolytic fragments with the antibodies and with other ligands (eg. heparin) allows one to determine overlaps between the fragments and to locate the positions of the different binding sites for antibodies and ligands. One of the antibodies has allowed us to identify a site of structural difference between cellular and plasma fibronectins from hamsters. The site recognized by this antibody is located near to, but not at, the C-terminal end and does not involve carbohydrate groups. Because of its internal location in fibronectin, this difference suggests that there are probably different genes for cellular and plasma fibronectin. These monoclonal antibodies should be useful for further probing the functions present in the C-terminal regions of fibronectin and for determining their locations.

Animals↗
PubMed1981

Pseudophakic cystoid maculopathy: a study of 50 cases.

The incidence of clinical cystoid macular edema (CME) in routine cataract surgery is about 2%. Clinically significant pseudophakic maculopathy has a higher incidence and is more severe. Fifty cases of CME following intracapsular cataract extraction and intraocular lens implantation in a series of 821 consecutive cases were reviewed. The overall incidence of pseudophakic cystoid macular edema (PCME) was 6.1%. Several clinical observations were made: (1) Young patients, or those under 65, had a much higher incidence of PCME, approaching 20%; (2) chronic inflammation is responsible for pseudophakic cystoid maculopathy; (3) systemic steroid therapy of CME in the pseudophakic patient was beneficial in 80% of the cases, with a response within ten days; and (4) pseudophakic cystoid maculopathy is almost always recurrent and frequently requires maintenance suppression with daily steroid drops after recovery. Forty-four percent of these patients did not recover better than 20/40 visual acuity, suggesting that CME in the pseudophakic patient is not a benign, self-limited disease.

Acetates↗
PubMed1981

Particle-free environment for refractive keratoplasty.

The refractive keratoplasty techniques of keratomileusis and keratophakia require meticulous care to avoid intralamellar foreign particles. A portable High Efficiency Particular Air Filter Unit has been designed to meet the needs of those surgeons clinically performing this surgery. The unit, combined with amorphic techniques has minimized the clinical problem of particulate matter for the general hospital.

Air Conditioning↗
PubMed1981

The effects of propylthiouracil and other drugs on the uptake of 75Se-selenomethionine by the pancreas.

The influence of pre-treatment with a variety of agents on the uptake of 75Se-selenomethionine by the rat pancreas has been studied. The agents ranged from thyroid hormones to protein synthesis inhibitors but out of 16 tested, only propylthiouracyl (50 mg/kg i.p. administered for 3 days prior to 75Se-methionine injection) resulted in a significant increase in the pancreatic uptake (17%) and in the pancreas liver concentration ratio (25%). Seven of the agents resulted in significant reductions in the pancreas/liver concentration ratios. No significant effects were produced by the addition of carrier methionine or selenomethionine (in the range 10-250 micrograms/kg body weight) to the injected radiopharmaceutical. It was concluded that many factors may influence the uptake, but that the interrelationship of hypothalamus, pituitary and pancreas is of particular interest.

Animals↗
PubMed1981

Keratophakia. Clinical evaluation.

The keratophakia and keratomileusis procedures of Barraquer for the correction of aphakia have not gained acceptance in the United States because of thier inherent complexity and degree of difficulty. To determine the practicality, feasibility, and visual rehabilitation potential of these procedures, 13 secondary keratophakia operations were performed at a 500-bed community hospital between March 1980 and April 1981. The first ten cases are reported to allow 6- to 12-month follow-up. All patients in the series were resistant to contact lenses or were poor candidates for secondary intraocular lens implantation. The anatomic results were excellent. Complications were minimal consisting of surface drying problems in three patients related to the sudden steepening of the cornea or pseudo keratoconus effect. Seven patients achieved 20/30 to 20/40 vision with minimal spectacle correction. The keratophakia procedure of Barraquer shows promise and can be duplicated by experienced corneal surgeons, but is not yet a viable alternative to the use of primary intraocular lenses and continuous wear lenses for the general ophthalmologist.

Adult↗