Biomedical subjects
Publications and source records attributed to H Ma.
We determined the content of substance P in the serum of 56 gravida with radioimmunoassay before and after acupuncture during the active period of the delivery. The result suggested that the acupuncture may be decline the content of substance P in the serum of the gravida, so that played role of analgesic effects.
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We have isolated cDNAs for a gene coding for a G protein alpha subunit from tomato (Lycopersicon esculentum, cv. VF36). This gene, named TGA1, was isolated using a cDNA of the Arabidopsis thaliana G protein alpha subunit-encoding gene, GPA1, as a DNA probe. The sequences of four cDNA clones indicate that the deduced amino acid (aa) sequence of the gene product (TG alpha 1) has 384 aa (44906 Da). The predicted TG alpha 1 protein exhibits similarity to all known G protein alpha subunits. The aa are 84.6% identical and 93% similar (identical and conservative changes) to A. thaliana GP alpha 1, and 34% identical and 59% similar to mammalian transducins. Furthermore, it has all of the consensus regions for a GTP-binding protein. Finally, hybridizations of tomato genomic DNA indicate that TGA1 is a single-copy gene.
The predicted products of floral homeotic genes, AGAMOUS (AG) from Arabidopsis thaliana and DEFICIENS A (DEF A) from Antirrhinum majus, have been shown previously to share strong sequence similarity with transcription factors from humans (SRF) and yeast (MCM1). The conserved sequence between these proteins is localized within a domain known to be necessary for the DNA binding and for the dimerization of SRF. We have isolated six new genes from A. thaliana, AGL1-AGL6, which also have this conserved sequence motif. On the basis of the sequence comparison between the AG and AGL genes, they can be assigned to two subfamilies of a large gene family. RNA dot blot analysis indicates that five of these genes (AGL1, AGL2, AGL4, AGL5, and AGL6) are preferentially expressed in flowers. In addition, in situ RNA hybridization experiments with AGL1 and AGL2 show that their mRNAs are detected in some floral organs but not in others. Our results suggest that these genes may act to control many steps of Arabidopsis floral morphogenesis. In contrast, the AGL3 gene is expressed in vegetative tissues as well as in flowers, suggesting that it functions in a broader range of tissues. We discuss possible roles of this gene family during the evolution of flowers.
ST segment change in procordial leads was analysed in 58 patients with acute inferior myocardial infarction (IMI). ST segment depression in V2 lead was negatively correlated with ST segment elevation in a VF lead in patients with IMI. ST segment depression in V2 lead was not observed when IMI was accompanied by right ventricular infarction. It indicates that ST segment depression in procordial leads was the reciprocal change of ST segment elevation in inferior leads. The direction and amplitude of ST segment shift in procordial leads may be affected by the presence of right ventricular infarction (RVI). The ratio of ST V2/ST aVF less than 0.5 may suggest a diagnosis of IMI with accompanying RVI.
Image and cytochemical analyses were undertaken to determine possible correlation between the number and size of acid phosphatase-positive granules (lysosomes), and variation in acid phosphatase (AcP) activity in the proximal tubule cells of mouse-kidney during growth and development. Eighteen ddY strain mice ages: 1 day, 1 and 2 weeks, and 1, 2 and 10 months were used. The lanthanide-based method for the ultrastructural localization of AcP-activity was employed. The number and size of AcP positive granules were quantitatively analyzed by image analysis, and AcP activity by X-ray microanalysis. Significance was evaluated by 2-tailed-Student's t-test for the difference between means. AcP activity was observed in the lysosomes and the reaction product appeared dense and heterogeneous. In some cells, it appeared apparently homogeneous. The results showed that the number and size of AcP Positive granules (lysosomes) increased significantly from the first day after birth, recorded a peak in one week time and thereafter, it gradually declined until the 10th month. The result of X-ray microanalysis demonstrated a variation in accordance with the degree of AcP activity at different ages of the animals studied. The AcP activity decreased significantly from day one and progressively until the 10th month. From the results of the present work, it could be inferred that the changes in size and number of AcP positive granules, at least, at the early stage, and/or the variation in AcP activity are related to the growth and development of the animal.
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Mutations in the homeotic gene agamous of the plant Arabidopsis cause the transformation of the floral sex organs. Cloning and sequence analysis of agamous suggest that it encodes a protein with a high degree of sequence similarity to the DNA-binding region of transcription factors from yeast and humans and to the product of a homeotic gene from Antirrhinum. The agamous gene therefore probably encodes a transcription factor that regulates genes determining stamen and carpel development in wild-type flowers.
The vectors and techniques described here enable one to manipulate the yeast genome to meet specific needs. Genes can be cloned, and the clone used to delete the wild-type gene from the chromosome, or replace it with mutant versions. Mutants derived by classical methods, such as mutagenesis of whole cells, or by reversion of a phenotype, can be cloned and analyzed in vitro. Yeast genes and foreign genes can either be inserted into autonomously replicating plasmid vectors that are reasonably stable or integrated into a yeast chromosome where they are maintained at one copy per genome. The combination of these techniques with the characterized promoter systems available in yeast make it possible to express almost any gene in yeast. Once this is achieved, the entire repertoire of yeast genetics is available to probe the function of the gene, or to engineer the expression in useful ways.
The circadian rhythm of body temperature (CTR) of male and female rats living at 23 degrees C, as well as their body temperature response to a yeast injection or to a 2-h exposure to 0 degree C, was investigated by telemetry. Young rats had a clear CTR with a mean nocturnal peak of 38.0 +/- 0.1 degree C and diurnal trough of 36.2 +/- 0.1 degree C. Older rats, starting at about 18 months of age, tended to have poor (that is, lower amplitude) rhythms. Mean daily body temperature was 37.1 +/- 0.2 degree C at all ages. After exposure to the cold, the body temperature of young rats, old rats with a strong CTR, and old rats with a poor CTR changed in the ranges of -0.3 to +1.5 degree C, -3.1 to +0.7 degree C, and -5.2 to +0.4 degree C, respectively. This indicates that old animals, especially but not exclusively those with poor CTRs, are less resistant to cold stress. On the other hand, the capacity to develop a fever in response to a yeast injection was equivalent in the three groups of animals, although females had a smaller response than males. It is concluded that the process of aging does not have a generalized debilitating effect on temperature regulation in rats. Rather, aging seems to affect individual components of the thermoregulatory system differentially.
We have isolated a gene coding for a G protein alpha subunit from the flowering plant Arabidopsis thaliana. This gene, named GPA1, was isolated by using a DNA probe generated by polymerase chain reaction based on protein sequences from mammalian and yeast G protein alpha subunits. The sequences of genomic and cDNA clones indicate that GPA1 has 14 exons, and the deduced amino acid sequence shows that the GPA1 gene product (GP alpha 1) has 383 amino acid residues (44,582 Da). The GP alpha 1 protein exhibits similarity to all known G protein alpha subunits--36% of its amino acids are identical and 73% are similar (identical and conservative changes) to mammalian inhibitory guanine nucleotide-binding regulatory factor alpha subunits and transducins. Furthermore, the GP alpha 1 protein has all of the consensus regions for a GTP-binding protein. The GPA1-encoded mRNA of 1.55 kilobases is most abundant in vegetative plant tissues, as determined by RNA blot analysis. Restriction fragment length polymorphism mapping experiments show that GPA1 is approximately 1.2 centimorgans from the visible marker er on chromosome 2.
The prevalence of ventricular late potentials (LP) in acute myocardial infarction (AMI) and the relationship between the presence of LP and the occurrence of spontaneous sustained ventricular tachycardia (VT) or fibrillation (VE) in the early phase (within 10 days) of AMI were studied. A total of 251 consecutive patients who had an uninterrupted natural history before special treatment formed this study. Sustained VT or VF occurred in 20 patients (8%). LP were recorded in 67 patients (27%). The incidence of LP was significantly higher among patients with VT/VF than among those without VT/VF (12 of 20, or 60%, vs 55 of 231, or 24%, P less than 0.01). The subgroup of patients whose VT/VF occurred within 1 hour of onset of AMI also showed a higher incidence of LP (5 of 9, or 56%, vs 55 of 231, or 24%, P less than 0.05). The results showed that the mechanism of VT/VF in early period including those happened within 1 hour of onset of AMI in man is due to reentry, and that LP can help to identify those high risk patients with a propensity to develop VT/VF in early period of AMI.
We studied the relationship between thrombolysis and late potentials (LP) in 137 patients with acute myocardial infarction (AMI). Among 37 patients treated with tissue-type plasminogen activator(t-PA treated group), LP were recorded in 2 patients (5%). In contrast, among 100 conventionally treated patients (control group), LP were seen in 26 (26%, P less than 0.01). When the two groups were matched with respect to age, sex, absence of prior infarction, LVEF, number of abnormal Q waves, ECG score and CAD score, the same incidence of LP was seen, i.e. 6% of the 34 t-PA treated patients had LP as compared with 24% of the 42 conventionally treated patients (P less than 0.05). Angiographic examination following t-PA infusion revealed that the incidence of LP was 0% and 40% in patients with patent and closed infarct-related coronary artery respectively. 1 year follow-up data showed that no deaths occurred in the t-PA treated group, while in the control group. 18 deaths were recorded and 8 of them were classified as sudden death. These observations suggest that patients with AMI treated early with thrombolysis have electrically more stable ventricles due to improvement of ischemia.
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Explore the source record for details and available documents.
The function of the N-terminal amino acids of Saccharomyces cerevisiae hexokinase II was studied in vivo using strains producing a form of hexokinase II lacking its first 15 amino acids (short form). This short form of hexokinase II was produced from a fusion between the promoter region of the PGK1 gene and the HXK2 coding sequence except the first 15 codons. As expected, the in vitro analysis of the short form protein by gel filtration chromatography indicates that the short protein does not form dimers under conditions where the wild-type protein dimerizes. Kinetic studies show that the enzymatic activities are very similar to wild-type behavior. The physiological experiments performed on the strains containing the fusion allele demonstrate that the short form of the enzyme is similar to the wild-type both in terms of phosphorylation of hexoses and glucose repression. We conclude that the N-terminal amino acids of hexokinase II are not required in vivo either for phosphorylation of hexoses or for glucose repression.
In order to confirm the efficacy of a new coronary prognostic index for the prediction of mortality of acute myocardial infarction in the Chinese in general, this index was applied to 886 patients from six general hospitals in Hong Kong (435 patients), Guangzhou (212 patients) and Shanghai (239 patients), respectively. They could be successfully stratified into seven clinical subsets with stepwise increasing mortality. The overall mortality tallied with that predicted by the original coronary prognostic index. The efficacy of this prognostic index for the prediction of mortality from acute myocardial infarction among the Chinese is verified and its application in the objective assessment of patients with acute myocardial infarction is recommended.