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Biomedical subjects

D Jackson

Publications and source records attributed to D Jackson.

At least 271 records · Page 15Linked to original sources
PubMed1981

Limiting factors in the site distribution of dental caries.

From records of 32 067 dentate persons from low fluoride communities in South Yorkshire, England, clinical dental caries has been scored at the distal and mesial sites of permanent canines, first and second premolars, and first and second molars, in relation to age. For those teeth with distal or mesial caries or both, the average number of distal and mesial sites attacked per DF tooth is calculated. The ratio observed generally reaches a stable value as age increases and is lowest for mandibular canines (1.10 from 15 years of age and above) and highest for mandibular first molars (1.46 from 30 years and above). For second premolars--both maxillary and mandibular--the ratio reaches a maximum at 30-39 years, and then falls with increasing age. Because the ratio generally attains an effective ceiling with increasing age at a level well below 2, and because it is characteristic of the tooth-type, host factors would seem to be implicated. The data corroborate the authors' hypothesis that the site-specificity of dental caries is genetically-determined and that the timing of attacks in a given environment is governed largely by endogenous factors.

Adolescent↗
PubMed1981

BRL 17421, a novel beta-lactam antibiotic, highly resistant to beta-lactamases, giving high and prolonged serum levels in humans.

BRL 17421 is a new semisynthetic beta-lactam antibiotic with an unusual spectrum of antibacterial activity. The compound exhibits exceptional stability to a wide range of bacterial beta-lactamases and is active against the majority of Enterobacteriaceae, including strains highly resistant to many of the penicillins and cephalosporins currently available. Among the clinical isolates of Enterobacteriaceae tested, the frequency of strains resistant to BRL 17421 was found to be low, and there was a slow rate of emergence of resistance during in vitro studies. BRL 17421 was highly active against Haemophilus influenzae and Neisseria gonorrhoeae, including beta-lactamase-producing strains. The compound was markedly less active against Pseudomonas aeruginosa and Bacteroides fragilis than against the Enterobacteriaceae. Against the gram-positive bacteria, BRL 17421 showed a very low level of activity. BRL 17421 was found to be 85% bound to human serum, and the antibacterial activity was diminished two- to fourfold in the presence of human serum. Against experimental infections in mice, the activity of BRL 17421 reflected the properties observed in vitro. Studies in human volunteers showed unusually high and prolonged serum concentrations of the compound after parenteral dosage, with a serum half-life of about 5 h, and approximately 85% of the dose was recovered unchanged in the urine. BRL 17421 was poorly absorbed after oral administration. The compound was well tolerated after intramuscular and intravenous administration in volunteers, with no adverse side effects.

Animals↗
PubMed1980

Population screening for congenital hypothyroidism.

A pilot screening programme for congenital hypothyroidism covering most of North London, Essex, Bedfordshire, and Hertfordshire entailed carrying out an assay of thyroid-stimulating hormone on single Guthrie dried blood spots. During one year 87 444 babies were screened and 26 cases of primary congenital hypothyroidism detected, giving an incidence of 1:3363. Only two cases (7.7%) had already been diagnosed on clinical grounds before the results of screening became available. In two other babies the diagnosis was delayed. The programme thus resulted in the early treatment of 22 babies, eight of whom already had pronounced features of hypothyroidism that had not been detected on routine clinical examinations. Although definitive evidence will not be available for some years, the results suggest that the prognosis for most of these babies is likely to be improved by early diagnosis; thus the introduction of national screening should be delayed no longer.

Congenital Hypothyroidism↗
PubMed1980

Neural tumors of the oral cavity. A review of the spectrum of benign and malignant oral tumors of the oral cavity and jaws.

The clinical and histologic features of benign and malignant neural tumors of the oral cavity and jaws are reviewed. Some rarer histologic variants are mentioned. Particular attention is paid to the two syndromes involving neural tumors of the oral cavity, namely, neurofibromatosis and multiple endocrine neoplasia III. A previously unreported case of the latter is presented.

Amputation Stumps↗
PubMed1980

Programming and running radioimmunoassay in the h-TSH screening procedure using dried blood spots and the NE1600 gamma counter on line to the HP9815S calculator.

Screening for hypothyroidism has been achieved by seeking raised concentrations of thyroid stimulating hormone (h-TSH) in dried blood samples collected on absorbent paper from some 1700 newborn babies each week using double antibody radioimmunoassay and 125I-label counting on a NE1600 gamma counter linked to a HP9815S desk top calculator. Specificity, accuracy, and quality control of the assay have been investigated. The calculator programme stores all count, time, and calculated data and uses log-log function formation and third-power homoscedastic polynomial fit to the calibration data followed, if necessary, by elimination of outliers set at P = 0.5%. Branching in the calculation procedure provides the ability to process sample data in subgroups, completely to reprocess data (including presentation in a form suitable for making a histogram plot), and to reset without loss of data in case of instrument or main power failure. Variance analysis was used to select the minimum duration of count (50 s), and it was demonstrated that homoscedasticity pertains in the regression calculation.

Analysis of Variance↗