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Biomedical subjects

A Maddison

Publications and source records attributed to A Maddison.

7 recordsLinked to original sources

Exon skipping induced by cold stress in a potato invertase gene transcript.

We show that two invertase genes in potato, like most other plant invertase genes, include a very short second exon of 9 bp which encodes the central three amino acids of a motif highly conserved in invertases of diverse origin. This mini-exon is one of the smallest known in plants and pre-mRNA from these genes may be susceptible to alternative splicing, because of a potential requirement for specialized interaction with the splicing machinery to ensure correct processing for the production of a mature mRNA. No evidence of aberrant post-transcriptional processing was observed during normal invertase gene expression in potato. The fidelity of post-transcriptional processing of the pre-mRNA from one of the genes was perturbed by cold stress, resulting in the deletion of the mini-exon from some transcripts. This alternative splicing event occurred under cold stress in both leaf and stem, but was not induced by wounding. This adds an example of exon skipping and the induction of alternative processing by cold stress to the small number of transcripts which have been shown to exhibit alternative splicing in plants. The differential sensitivity of post-transcriptional processing to cold stress observed for the two transcripts examined will permit further dissection of the nucleotide sequence requirements for their accurate splicing.

Alternative Splicing↗

Variability of electrocardiographic and enzyme evolution of myocardial infarction in man.

We have studied the time course of development of ST segment elevation, R wave loss, and Q wave development in 41 patients using 35 lead praecordial mapping or 12 lead electrocardiograms in those with anterior and inferior infarcts, respectively. The first recording was at a mean time of six hours after the onset of pain; subsequent records were taken every eight hours for 24 hours, every 12 hours for the second day, and every day thereafter. Serial CK MB estimates were obtained at every four hours for the first 72 hours. There was good agreement in the time course between the electrocardiogram and enzyme evolution. Forty-one per cent of patients showed rapid infarction with R wave and Q wave evolution complete within 12 hours of pain and accompanied by a short duration of enzyme release (mean = 19.30 hours). Fifty-nine per cent of patients showed more prolonged infarction with longer R wave and Q wave evolution and enzyme release (mean = 30 hours). Four patients also showed delayed reinfarction. ST segment elevation was maximal at six hours in the whole group and was significantly lower thereafter. Patients with rapid infarction showed high initial ST segment elevation which decreased promptly compared with those with prolonged infarction, who showed moderate but more persistent ST segment elevation. This study shows the variability in the time course of the electrocardiogram and enzyme evolution after myocardial infarction in man.

Aged↗

The role of serum myoglobin in the detection and measurement of myocardial infarction.

The use of serum myoglobin determinations in the diagnosis and quantitation of acute myocardial infarction was studied in 53 patients. Serial blood samples collected for the first 72 h after pain were analysed for serum myoglobin using a radioimmunoassay procedure. Samples were also assayed for serum creatine kinase (CK) and its myocardial isoenzyme CK-MB, aspartate aminotransferase (AST) and alpha-hydroxybutyrate dehydrogenase (alpha HBDH). Analysis of first and second samples obtained at mean times of 7.6 and 10.7 h respectively after pain produced the following detection rate: serum myoglobin 85% and 98%; serum CK 71% and 85%; serum AST 58% and 81%; serum CK-MB 29% and 60%; serum alpha HBDH 23% and 33% respectively. Total CK-MB and myoglobin release from damaged myocardium were calculated using the method of Norris et al. [16]. A significant correlation was obtained between infarct size calculated from CK-MB and myoglobin in the whole group (n = 29, r = 0.71, p < 0.001). The correlation was even more significant for smaller infarcts with CK-MB release < 220 U/l (n = 13, r = 0.92, p < 0.001).

Adult↗

Serum high density lipoprotein cholesterol determination: a simple modification.

A simple modification to the method of Burnstein et al. (Burnstein, M., Scholnick, H.R. and Morfin, R. (1970) J. Lip. Res. 11, 583) [1] for the measurement of serum high-density lipoprotein (HDL) cholesterol concentrations is reported. The modification obviates the need for a refrigerated centrifuge and makes the method suitable for routine use in almost any laboratory. Good correlation was obtained for values in 80 healthy adults using the method as originally described by Burnstein et al. [1] and then with the modification. The presented method was linear and precise and the study showed that it was not necessary to fast before giving a blood sample for the assay. It was found that HDL cholesterols were higher in women than in men, but did not change significantly with age in either group.

Adult↗

Value of electrocardiogram in predicting and estimating infarct size in man.

The value of the electrocardiogram in assessing infarct size was studied using serial estimates of the MB isomer of creatine kinase (CK MB) in plasma, serial 35 lead praecordial maps in 28 patients with anterior myocardial infarction, and serial 12 lead electrocardiograms in 17 patients with inferior myocardial infarction. In patients with anterior infarcts, sigma ST, sigma R, sigma Q, sigma R/(Q+S), and the number of sites with ST elevation more than 2 mm or with QS waves, were obtained from each map. Correlation between both maximum sigma Q and maximum sigma ST with cumulative CK MB was highly significant. There was also a significant correlation between sigma R and sigma R/(Q+S) with cumulative CK MB. There was no significant correlation between maximum number of sites with ST elevation or with Q or QS waves and cumulative CK MB. Maximum sigma ST and number of sites with ST elevation predicted maximum sigma Q and number of sites with QS or Q waves at a time when infarction was not complete. In patients with inferior infarcts, there was a significant correlation between maximum sigma Q and maximum sigma ST in leads II, III, and a VF, and cumulative CK MB. This study shows that all the waves in the electrocardiogram are useful in assessing infarct size. The fact that maximum sigma ST predicts final sigma Q may be used to assess the efficacy of interventions designed to salvage ischaemic myocardium.

Aged↗

Ratio of urinary 6beta-hydroxycortisol to 17-hydroxycorticosteroids in patients with liver disease.

The ratio of 6beta-hydroxycortisol to 17-hydroxycorticosteroids in the urine of 73 patients with liver disease, and 53 controls has been measured. The mean ratio was significantly greater in the liver disease group (p less than 0.001), this elevation being most marked among patients with liver metastases and patients with acute hepatitis. We feel that the use of the ratio as a test of early liver cell dysfunction requires further evaluation, in particular in the early recognition of metastatic liver disease.

17-Hydroxycorticosteroids↗