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Biomedical subjects

H W Taylor

Publications and source records attributed to H W Taylor.

At least 73 records · Page 4Linked to original sources
PubMed1982

Measurement of magnesium by continuous-flow colorimetry.

We describe the application to the Technicon SMAC system of a micellar-improved calmagite method for the measurement of magnesium. In this continuous-flow method a dialyzer is not needed, because protein interference is negligible. Sample interaction was estimated to be 3%. The increased sensitivity of the method allows for a small sample volume (37 microL/min). Results obtained agreed well with those by an atomic absorption procedure (x): SMAC magnesium - 0.971 x + 0.030 mmol/L (n = 58). The estimated total error for the SMAC procedure was less than 50 mumol/L at two analyte concentrations: 0.50 and 1.50 mmol/L. The inclusion of magnesium estimation on SMAC should extend the screening function of this analyzer.

Colorimetry↗
PubMed1980

Myocarditis induced by parvoviral infection in weanling pups in the United States.

In a nationwide survey from January 1978 through September 1979, acute parvovirus-induced myocarditis was identified in 76 of 147 (52%) pups in 19 litters. The affected pups were from 12 states. Birth of all pups registered with the American Kennel Club during this period increased during the spring months, peaking in May, which was correlated in 4 to 8 weeks with the greatest number of cases in the study. Serologic data available for 4 dams, for 6 of their surviving pups, and for 3 contact pups indicated that all had been exposed to parvovirus. In 2 kennels, cases of acute myocarditis were preceded within 2 months by cases of severe gastroenteritis in older litters on the same premises.

Animals↗
PubMed1980

Spatial patterns of age-sex structures in Costa Rica: a study in demographic modernization.

The relationship between economic development and demographic factors in Costa Rica is examined. "Specifically, the paper illustrates the evolution of spatial patterns in age-sex structures over three points in time for a single case study area." The authors suggest that there is order in the evolving patterns and that this order may be explained by the economic modernization process. Data are from the 1950, 1963, and 1973 censuses. Although some spatial order is indicated, the patterns are confused primarily by an increase in fertility that apparently occurred between 1950 and 1963.

Age Distribution↗
PubMed1979

Carcinogenicity of chlorinated nitrosotrialkylureas in rats.

Four chlorinated derivatives of nitrosotrialkylureas were tested for carcinogenicity by oral administration by gavage to Sprague-Dawley rats. All of the compounds were very toxic, and all were carcinogenic, inducing tumors of the non-glandular stomach and of the lungs. The commonest tumors were carcinomas and papillomas of the non-glandular stomach and alveolar cell adenomas of the lungs. Nitrosochloroethyldimethylurea induced most tumors, but it was possible to administer higher doses of this compound than of the others, which were nitrosochloroethydiethylurea, nitrosomethylbis-(chloroethyl)-urea and nitrosotris-(chloroethyl)-urea. The last of these was a particularly toxic compound so that the maximum total dose given was only 0.07 millimole per rat.

Animals↗
PubMed1979

Carcinogenicity of methylated derivatives of N-nitrosodiethylamine and related compounds in Sprague-Dawley rats.

Five nitrosamines, which can be considered alkyl derivatives of N-nitrosodiethylamine, were tested for carcinogenicity by administration to Sprague-Dawley rats in drinking water at approximately equimolar concentrations. N-Nitrosodi-n-propylamine was a potent carcinogen but less so than N-nitrosodiethylamine and gave the same spectrum of tumors. N-Nitrosodiisopropylamine was very much weaker than N-nitrosodiethylamine and induced only tumors of the nasal turbinates in significant incidence. At the doses given, neither N-nitrosodiisobutylamine nor N-nitrosodi-sec-butylamine was significantly carcinogenic. In contrast, the cyclic nitrosamine N-nitrosohexamethyleneimine was equally potent with N-nitrosodiethylamine and gave the same spectrum of tumors in liver, esophagus, and nasal turbinates. The results support the concept that oxidation at the alpha carbon atom of nitrosamines is a significant step in carcinogenesis.

Animals↗
PubMed1978

The change in carcinogenic effectiveness of some cyclic nitrosamines at different doses.

The carcinogenic effectiveness in rats of three cyclic nitrosamines administered at two doses separated by a factor of five has been studied. All three compounds showed a response at the lower dose quite different from that at the higher dose. One, 2,6-dimethyl-dinitrosopiperazine, was only a little less effective at the lower dose than at the higher dose, giving 100% nasal turbinate tumors, but only 33% esophageal tumors, compared with 100% esophageal tumors at the higher dose. 3,4-Dichloronitrosopiperidine gave 100% incidence of esophageal tumors at the higher dose. At the lower dose, survival of the rats was very much better, some living 80 weeks, and, in addition to the esophagus, there were tumors of several organs including forestomach, tongue, and nasal turbinates. On the other hand, 2,6-dimethylnitrosomorpholine was a very much weaker carcinogen at the lower than at the higher dose, only six animals dying with tumors, compared with 100% incidence at the higher dose. However, the pattern of mortality of rats given the lower dose of dimethylnitrosomorpholine was similar to that of rats given the lower dose of dichloronitrosopiperidine.

Animals↗
PubMed1978

Carcinogenicity of 4-chloronitrosopiperidine in Sprague-Dawley rats.

4-Chloronitrosopiperidine was administered to a group of 15 male Sprague-Dawley rats as a 0.005% solution in drinking water for 27 weeks. Of the 15 animals, 12 died with tumors induced by the treatment, half of them by the 41 st week; all 15 were dead at 58 weeks. Seven rats had liver tumors, 5 had esophageal tumors, 2 had tumors of the nonglandular stomach and 2 had tumors of the nasal turbinates. Several rats had tumors of more than one organ.

Animals↗
PubMed1978

A computer model in the selection of multiple channel analysers.

1. A simple computer model is described which was used to study possible test combinations on automated multichannel analysers. Specific objectives were minimisation of manpower and maximisation of throughput of the specimen preparation process. 2. In our case, by appropriate test combination selection, a staff saving of 50% in the aliquotting process is predicted. For tests that are available on multichannel analysers, a reduction from 198 to 121 aliquots per 100 patient specimens is expected on an 18 channel machine. With the use of filter separation systems, manual aliquotting would be required for 21 specimens per 100.

Autoanalysis↗
PubMed1978

A study of factors affecting laboratory workload.

1. The use of a mathematical modelling technique is described. The factors influencing the day to day variation in laboratory workload were investigated to provide for accurate management forecasts. Analysis by linear stepwise regression showed that a potentially controllable factor the clinician ordering habits, accounted more significantly in this variation than less controllable factors such as admissions, routine and acute, total occupied beds and public holidays. 2. The significant factors remained valid after a review period of one year.

Laboratories↗
PubMed1978

Carcinogenesis of nitrosomethylundecylamine in Fischer rats.

Nitrosomethylundecylamine was synthesized and administered to Fischer rats by gavage in olive oil solution, at a dose of 46 mg/animal/week for 30 weeks. There were high incidences of hepatocellular carcinomas and cholangiocarcinomas in the liver and of squamous cell carcinomas and alveolar cell adenocarcinomas in the lung. In contrast with the activity of the next higher homolog, nitrosomethyldodecylamine, no bladder tumors were induced.

Adenocarcinoma, Bronchiolo-Alveolar↗
PubMed1978

Comparison of bladder carcinogenesis by nitrosomethyldodecylamine in Sprague--Dawley and Fischer rats carrying transplanted bladder tissue.

Nitrosomethyldodecylamine was given by gavage in oliver oil solution (25 mg twice/week) to male and female Sprague--Dawley and Fischer rats to the back of each of which had been transplanted a suspension of urinary bladder tissue from the same strain. While there was 100% incidence of transitional cell carcinomas in the host urinary bladders, and few other tumors in the animals, there was a tumor in only 1 transplant in a Sprague--Dawley rat, with a possible tumor in another, and none in the Fischer rat, although these were inbred. In a significant number of cases the transplant survived.

Animals↗
PubMed1978

Relative carcinogenic effectiveness of derivatives of nitrosodiethylamine in rats.

The carcinogenicity of five derivatives of nitrosodiethylamine was compared with that of the parent compound by p.o. administration to rats. All were less potent than was nitrosodiethylamine. When nitrosobis(2-methoxyethyl)amine and nitrosobis(2-ethoxyethyl)amine were administered at equimolar doses in drinking water, there was a high incidence of liver tumors, but the animals died later than they did after nitrosodiethylamine treatment, which also induced esophageal tumors. Nitrosoiminodipropionitrile and nitrosobis(2,2-diethoxyethyl)amine failed to induce tumors at the same dose level. Nitrosobis(2-chloroethyl)amine was administered in oil by gavage at a dose lower than that of nitrosodiethylamine and produced a much weaker tumor response; 5 of 15 treated rats had forestomach papillomas, and 1 had olfactory adenocarcinoma and no other induced tumors.

Administration, Oral↗
PubMed1977

A random blood sugar diabetes detection survey.

In a co-operative study undertaken between various groups in the community, 3212 persons were screened at the Agricultural and Pastoral Summer Show in Christchurch. The mean glucose value was 88.4 mg/dl (4.9mmol/l) which roughly equates to 91 mg/dl (5.1mmol/l) plasma value. There was a standard deviation of 19.5mg/dl (1.08mmol/l) the 22.5 percentile was 63mg (3.5mmol/l), the 97.5 percentile was 125 (6.5mmol/l). One hundred and twenty persons of the total of 3212 were advised to contact their family doctors as a result of higher than normal blood sugar levels on the day. Twenty-five probable diabetics were diagnosed.

Adult↗