The clinical significance of ischaemia-modified albumin in acute coronary syndrome and hypertension.

BACKGROUND: Early diagnosis of acute coronary syndrome is more and more important because of its mortality and morbidity. Hypertension is one of the pathogenesis of acute coronary syndrome, which often leads to stenosis and ischaemia. Ischaemia-modified albumin is sensitive for the occurrence of ischaemia, which attracted us in the significance of ischaemia-modified albumin in patients with chest pain, especially patients complicated with hypertension. METHODS: In total, 200 patients with acute chest pain were included in the study. According to the diagnostic criteria, patients were divided into acute coronary syndrome group and non-ischaemic chest pain group. Cardiac biomarkers were measured with 30 minutes in emergency department, including cardiac troponin T, creatine kinase MB, and ischaemia-modified albumin. Receiver operating characteristic curve (ROC) analysis was used for the sensitivity and specificity of ischaemia-modified albumin in the early diagnosis of acute coronary syndrome. Comparisons between ischaemia-modified albumin and cardiac Troponin T were done between groups. RESULTS: The demographics in two groups were not significantly different in most aspects. Compared with non-ischaemic chest pain group, serum levels of ischaemia-modified albumin and cardiac Troponin T were significantly higher in acute coronary syndrome group. ROC analysis showed that ischaemia-modified albumin had a good sensitivity and specificity in early diagnosis of acute coronary syndrome. The level of ischaemia-modified albumin in acute coronary syndrome patients with hypertension was higher than that in non-ischaemic chest pain patients. CONCLUSIONS: In patients complained with acute chest pain, the serum measurement of ischaemia-modified albumin is potential valuable for the early diagnosis of acute coronary syndrome, especially combined with ECG. The serum level of ischaemia-modified albumin in acute coronary syndrome patients is significantly associated with hypertension.

Systematic analysis of alternative first exons in plant genomes.

BACKGROUND: Alternative splicing (AS) contributes significantly to protein diversity, by selectively using different combinations of exons of the same gene under certain circumstances. One particular type of AS is the use of alternative first exons (AFEs), which can have consequences far beyond the fine-tuning of protein functions. For example, AFEs may change the N-termini of proteins and thereby direct them to different cellular compartments. When alternative first exons are distant, they are usually associated with alternative promoters, thereby conferring an extra level of gene expression regulation. However, only few studies have examined the patterns of AFEs, and these analyses were mainly focused on mammalian genomes. Recent studies have shown that AFEs exist in the rice genome, and are regulated in a tissue-specific manner. Our current understanding of AFEs in plants is still limited, including important issues such as their regulation, contribution to protein diversity, and evolutionary conservation. RESULTS: We systematically identified 1,378 and 645 AFE-containing clusters in rice and Arabidopsis, respectively. From our data sets, we identified two types of AFEs according to their genomic organisation. In genes with type I AFEs, the first exons are mutually exclusive, while most of the downstream exons are shared among alternative transcripts. Conversely, in genes with type II AFEs, the first exon of one gene structure is an internal exon of an alternative gene structure. The functionality analysis indicated about half and approximately 19% of the AFEs in Arabidopsis and rice could alter N-terminal protein sequences, and approximately 5% of the functional alteration in type II AFEs involved protein domain addition/deletion in both genomes. Expression analysis indicated that 20-66% of rice AFE clusters were tissue- and/or development- specifically transcribed, which is consistent with previous observations; however, a much smaller percentage of Arabidopsis AFEs was regulated in this manner, which suggests different regulation mechanisms of AFEs between rice and Arabidopsis. Statistical analysis of some features of AFE clusters, such as splice-site strength and secondary structure formation further revealed differences between these two species. Orthologous search of AFE-containing gene pairs detected only 19 gene pairs conserved between rice and Arabidopsis, accounting only for a few percent of AFE-containing clusters. CONCLUSION: Our analysis of AFE-containing genes in rice and Arabidopsis indicates that AFEs have multiple functions, from regulating gene expression to generating protein diversity. Comparisons of AFE clusters revealed different features in the two plant species, which indicates that AFEs may have evolved independently after the separation of rice (a model monocot) and Arabidopsis (a model dicot).