Biomedical subjects
Publications and source records attributed to K Howard.
452 male technical and vocational students aged 16-25 years old were surveyed for their dietary habits at Riyadh, Saudi Arabia. The data presented here cover the habit of meal skipping. Results showed that dinner was skipped by 28%, breakfast by 20% and lunch was skipped by 15%. Differences are discussed according to age cohorts and accommodation status subgroups.
Dietary habits of 452 young adult male students at 6 technical institutes and vocational training centres in Riyadh, Saudi Arabia were investigated as part of a nutritional assessment survey. The eating-between-meals habit was found to be common among the majority (72.3%) of those students. The association between this habit and age cohorts, marital status, accommodation status, self assessment of weight and exercising are discussed.
An artificial intelligence expert-based system for facilitating the clinical recognition of occupational and environmental factors in lung disease has been developed in a pilot fashion. It utilizes a knowledge representation scheme to capture relevant clinical knowledge into structures about specific objects (jobs, diseases, etc) and pairwise relations between objects. Quantifiers describe both the closeness of association and risk, as well as the degree of belief in the validity of a fact. An independent inference engine utilizes the knowledge, combining likelihoods and uncertainties to achieve estimates of likelihood factors for specific paths from work to illness. The system creates a series of "paths," linking work activities to disease outcomes. One path links a single period of work to a single possible disease outcome. In a preliminary trial, the number of "paths" from job to possible disease averaged 18 per subject in a general population and averaged 25 per subject in an asthmatic population. Artificial intelligence methods hold promise in the future to facilitate diagnosis in pulmonary and occupational medicine.
During the first 3h of development the Drosophila blastoderm is subdivided into segments along the anterio-posterior axis. This is achieved by three classes of genes: gap, pair-rule and segment polarity. The gap and pair-rule genes interpret cues provided by the localized maternal determinants. These transient intermediate patterns then establish the persistent segment polarity gene expression which defines segments throughout development. In so doing they transform maternal gradients which vary gradually over a distance of 40 or so cells into a precise pattern where individual cells are distinguished from their immediate neighbors.
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This competitive, solid-phase enzymoimmunoassay for testosterone in saliva is carried out on microtiter plates and involves no chromatographic or extraction steps. With an overnight incubation the detection limit of the assay is 230 fg per well (16.1 pmol/L). There was a good correlation (correlation coefficient 0.95) between testosterone concentrations measured with and without prior extraction of the saliva samples. Repeated assay of three control saliva samples containing a range of testosterone concentrations (200-1000 pmol/L) gave within- and between-assay coefficients of variation of 5.5-13.2%. The analytical procedure is simple and closely resembles already published procedures for the determination of progesterone and estrone (with extraction) in saliva. One person can assay 200 samples in 24 h and the assay is suitable for reproductive and sports medical applications, particularly for projects involving serial sampling and yielding large numbers of samples.
1. The stimulated levels of phenylanine hydroxylase activity in liver extracts from streptozotocin-induced diabetic rats (Donlon and Beirne, 1982) have been correlated with an increased rate of phenylalanine catabolism in vivo. 2. The levels of hepatic phenylalanine hydroxylase protein in diabetic rats become elevated. This effect is not seen in diabetic animals concurrently treated with insulin. 3. The rate of synthesis of liver phenylalanine hydroxylase in 5-day diabetics is 260% that of control animals. 4. These observations are discussed with reference to the regulation of hepatic phenylalanine hydroxylase and phenylanine metabolism in rats.
Platinum concentrations were determined in autopsy tumor samples obtained from 27 patients who had received cisplatin 40-1,029 mg/m2 from 0 to 240 days antemortem. Liver metastases had significantly higher platinum concentrations than did tumors in other sites (p less than 0.005). Platinum concentrations in liver metastases were similar to platinum concentrations in normal liver. Platinum concentrations in gliomas and brain metastases were similar to platinum concentrations in other extrahepatic tumors. Platinum concentration generally decreased with increasing distance into brain from tumor. By multiple stepwise linear regression analysis, the factors that were independently most closely associated with tumor platinum concentration were time from last cisplatin treatment, cumulative lifetime dose of cisplatin, route of cisplatin administration (intraarterial vs. other), and site of tumor deposit (liver vs. other) (r = 0.69, p less than 0.001). Patients whose tumors had responded to cisplatin-containing regimens had mean tumor platinum concentrations that were higher than the mean tumor platinum concentrations in patients whose tumors had not responded to cisplatin (p less than 0.05).
An essential step in the Drosophila segmentation mechanism is the expression of the pair-rule gene hairy in a periodic pattern in the blastoderm. In this paper we describe four regulatory hairy mutations. Using in situ hybridization, we show that these mutations cause alterations in the normal pattern of hairy expression. The new patterns are partial versions of the wild-type pattern and indicate that there are regulatory sequences associated with hairy that respond to distinct cues in different parts of the blastoderm. This suggests that a major function of hairy is to decode a prepattern consisting of complex cues (probably generated by the coordinate and gap classes of segmentation genes) into a simple periodic pattern. We have located the mutations on the DNA map of the hairy gene. They identify a 5' region of approximately less than 20 kb necessary for this decoding function.
Data validity is a fundamental problem in epidemiology. An objective of birth defect registers is the collection of high quality data, often from a number of sources, for use in epidemiological research. This paper examines the use of data from a national register in New Zealand in the study of congenital heart defects. The prevalence rates of congenital heart defects are shown to depend on the definition of the terms employed, the methods and completeness of the case ascertainment, the correctness of the diagnoses, the nature and size of the population under study, and the duration of followup. Recommendations are made for increasing the utility of this register in the study of this major group of malformations.
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The genetic loci fushi tarazu (ftz), hairy (h), and engrailed (en) must be expressed during embryogenesis for the correct segmental organization of the Drosophila embryo to be established. Transcripts from these genes accumulate in periodic patterns at the blastoderm stage of development. We demonstrate that generation of the normal pattern of ftz RNA requires the h+ function whereas formation of the h pattern does not require the ftz gene. In addition, we show that the en pattern is altered in both h and ftz mutant embryos. The nature of these changes and the cuticular phenotype of h mutant larvae suggest that both h and ftz phenotypes are a consequence of incorrect compartmentalization and that the effect of h is mediated via ftz and other genes.
The survival of Escherichia coli in an aerosol was studied at several temperatures and over a range of relative humidities using a Henderson apparatus. Death occurred in two phases, the first lasting approximately 1 min; in the second the number of viable microorganisms declined exponentially. E. coli was robust and remained viable for many hours. Death was most rapid at low humidities (less than 50% r.h.) at 15 and 30 degrees C, with half-lives of 14 and 3 min respectively. In humid conditions the half-lives were much longer, approximately 83 and 14 min respectively. Based on this work, preliminary recommendations for the climate of livestock buildings can now be given to control the airborne spread of E. coli.
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Autopsy tissues were obtained from 30 patients who had received cisplatin antemortem; the tissues were assayed for platinum by flameless atomic absorption spectrometry. Patients with antemortem evidence of renal toxicity had higher renal cortical platinum concentrations than did patients without evidence of kidney damage. In addition, patients with nephrotoxicity were more likely than patients without toxicity to have renal cortical platinum concentrations that were higher than renal medullary platinum concentrations. Overall, the two variables most closely associated with an increase in serum creatinine with treatment were renal cortical platinum concentration (P less than .02) and cumulative dose of cisplatin (P less than .05). These two variables were important independently of one another. Renal cortex platinum concentrations correlated inversely with time from last treatment until death, whereas hepatic platinum concentrations did not. In contrast, hepatic platinum concentrations correlated with dose of cisplatin while renal platinum concentrations did not. Our results suggest the following: (1) cisplatin-induced renal toxicity is tissue-platinum-concentration dependent and cisplatin-dose dependent; and (2) cisplatin may be handled differently at the molecular level in liver and kidney.
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