Search PubMed⌕ Search

Biomedical subjects

M Wu

Publications and source records attributed to M Wu.

At least 433 records · Page 24Linked to original sources
PubMed1993

Secreted noggin protein mimics the Spemann organizer in dorsalizing Xenopus mesoderm.

A dorsalizing signal acts during gastrulation to change the specification of lateral mesodermal tissues from ventral (blood, mesenchyme) to more dorsal fates (muscle, heart, pronephros). This signal, from Spemann's organizer, cannot be mimicked by the mesoderm inducers activin and fibroblast growth factor. The gene noggin is expressed in the organizer, and could be the dorsalizing signal. Here we show that soluble noggin protein added to ventral marginal zones during gastrulation induces muscle, but that activin does not. Dorsal pattern can be partially rescued in ventralized embryos by injection of a plasmid that expresses noggin during gastrulation. The results suggest that the noggin product may be the dorsalizing signal from the organizer.

Activins↗
PubMed1993

Association between plasma fibrinogen concentration and five socioeconomic indices in the Kuopio Ischemic Heart Disease Risk Factor Study.

The association between five socioeconomic indices (lifetime occupation, education, income, ownership of material possessions, and childhood socioeconomic status) and plasma fibrinogen levels was investigated in middle-aged Finnish men who were part of the Kuopio Ischemic Heart Disease Risk Factor Study. The Kuopio Ischemic Heart Disease Risk Factor Study is based on a representative age-stratified sample of 2,682 men aged 42, 48, 54, and 60 years. The data were collected between 1984 and 1989. The present analysis is restricted to the 2,011 men for whom information on fibrinogen and all covariates was available. The covariates were alcohol consumption, body mass index, physical fitness, smoking, coffee consumption, high density lipoprotein cholesterol, low density lipoprotein cholesterol, blood leukocyte count, and prevalent disease (at least one sign of ischemic heart disease, hypertension, diabetes, or previous stroke). An age-adjusted inverse association was found between levels of plasma fibrinogen and four of the five socioeconomic indices: current income, education, lifetime occupation status, and current material possessions. After adjustment for the covariates, the association persisted for education, current income, and lifetime occupation. Analysis of the joint effect of childhood and adult socioeconomic status indicated that those who were economically disadvantaged at both times had the highest fibrinogen levels, but the fibrinogen levels of those who were not poor as adults had no variation by childhood socioeconomic status.

Adult↗
PubMed1993

Posttranscriptional accumulation of chloroplast tufA (elongation factor gene) mRNA during chloroplast development in Chlamydomonas reinhardtii.

Light induces chloroplast (Cp) differentiation in dark-grown y-1 strains of Chlamydomonas reinhardtii. Slot blot analysis was used to quantitate tufA, psbA, psbK, rbcL, and 16S rRNA transcript accumulation and transcription during Cp differentiation. When etiolated cc-125 y-1 cells were illuminated for 5 h, a 1710 bp tufA mRNA accumulated up to 5-fold while the psbA, rbcL, and 16S rRNA transcripts accumulated less than 1.5-fold. The tufA gene encodes translational elongation factor EF-Tu. The light-induced accumulation of tufA mRNA did not occur in cc-1931, a strain that does not become etiolated in darkness. Pulse labelling was used to measure the transcription of Cp transcripts during tufA mRNA accumulation, and no detectable change in tufA transcription was observed. These results imply that the half life of the tufA transcript increases during the greening process.

Amino Acid Sequence↗
PubMed1993

Nucleotide sequence of a flower-specific MADS box cDNA clone from orchid.

An orchid (Aranda deborah) mature flower cDNA library was screened with an agamous cDNA probe from Arabidopsis. One positive clone for agamous gene was isolated, cloned and sequenced. This cDNA clone (om1) has a full length open reading frame of 750 bp corresponding to 250 amino acid residues. Comparison of om1 MADS box with that of its counterparts in tomato and Arabidopisis reveals significantly high homology (> 95%). Northern analysis indicated this gene is expressed in mature flowers and not in young developing inflorescences or young floral buds. In the mature flowers, it is only expressed in petals and weakly in sepals but not in the column (gynostemium).

Amino Acid Sequence↗
PubMed1993

Nucleotide sequence and in vitro translation of the coat protein gene of cymbidium mosaic virus.

The nucleotide sequence of the coat protein gene of cymbidium mosaic virus (CyMV) has been determined from a cDNA clone that encompassed the 3'-region of the virus genome. The 0.75 kb coat protein open reading frame (ORF) codes for a 24kD polypeptide. The coat protein coding region was separated from the 3'-poly(A) terminal of the viral genome by an 80 base noncoding region. The derived amino acid sequence of this ORF showed considerable homology with other potexvirus coat protein sequences, notably with narcissus mosaic virus (NMV), potato virus X (PVX), and white clover mosaic virus (WClMV). In vitro expression of the CyMV coat protein gene was carried out by T7 RNA polymerase on the linearized cDNA clone template, followed by in vitro translation of the purified transcript in wheat germ extract. One of the translated products was found to comigrate with the coat protein of the virus at about 24 kD, as determined by NaDodSO4-PAGE. This translated product was also found to crossreact with antibodies raised against CyMV.

Amino Acid Sequence↗
PubMed1993

Nucleotide sequence of a Singapore isolate of zucchini yellow mosaic virus coat protein gene revealed an altered DAG motif.

A cDNA clone of zucchini yellow mosaic virus (ZYMV) RNA was mapped to the 3' terminal region. The nucleotide sequence revealed a single open reading frame of 1035 nucleotides followed by a 3' noncoding region of 215 nucleotides. The putative protease cleavage site for the release of coat protein (CP) was deduced to be between Glu-Ser (at amino acid position 66-67), which would result in a protein of 279 amino acids. This non-aphid-transmissible Singapore isolate of ZYMV showed a change of DAG to GAG triplet near the N-terminal of the CP. The CP gene was expressed as a protein fused to the beta-galactosidase in Escherichia coli and as an unfused protein in Saccharomyces cerevisiae.

Amino Acid Sequence↗
PubMed1993

Design of the Lung Health Study: a randomized clinical trial of early intervention for chronic obstructive pulmonary disease.

The Lung Health Study is a multicenter randomized clinical trial. Participants are smokers aged 35-60 with spirometric evidence of moderate lung function impairment. The objective of the trial is to determine whether a program of smoking intervention and use of an inhaled bronchodilator can slow the rate of decline in pulmonary function over a 5-year follow-up period. This paper describes the background, design, sample size (approximately 6000 participants), and power estimates for the trial, as well as the treatment program and the rationale for the choice of inhaled bronchodilator. Plans for analysis of changes in pulmonary function parameters and for analysis of participants' survival and smoking-related morbidity are also discussed.

Administration, Inhalation↗
PubMed1993

Differential effects of quinpirole in the nucleus accumbens depending on the initial level of locomotor activity.

Effects of dopamine D1 and D2 receptor agonists (SKF 38393 and quinpirole, respectively) on locomotion were studied in two behavioural situations characterized by low and high level of exploratory locomotor activity. Administration of quinpirole bilaterally into the nucleus accumbens increased locomotor activity at the low initial level of activity and decreased locomotor activity at the high activity level, while the administration of SKF 38393 increased locomotor activity in both behavioural situations. It was concluded that quinpirole has differential effects on locomotion, depending on the initial level of activity.

2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben↗
PubMed1993

Studies of metaphase and interphase chromosomes using fluorescence in situ hybridization.

Our measurements have bearing on the resolution with which maps can be constructed and abnormalities can be detected by studying the proximity of DNA sequences in metaphase and interphase chromosomes. The results of our analyses are summarized in Figure 8. Metaphase chromosomes are compacted sufficiently that it is impractical to order sequences separated by less than approximately 1 Mbp. In contrast, 100-kbp resolution can be obtained in interphase chromosomes. Distance measurements reveal that interphase chromatin behaves as a random polymer over distances up to 1-2 Mbp. At greater distances, higher order constraints, perhaps the dimensions of the individual chromosome domains, come into play. A caveat remains: Because the effect of the FISH procedure on native chromosome organization is not well understood, these conclusions may not be applicable to native chromatin. We have illustrated that FISH, with appropriately chosen probes, can supplement conventional cytogenetics in the study of chromosome abnormalities. The technique is increasingly being applied in research laboratories to detect and characterize chromosome abnormalities and point the way to the location of genes involved in human disease.

Chromosome Aberrations↗
PubMed1993

Role of heredity in the genesis of myopia.

Previous studies suggest that myopia in parents may influence the genesis of myopia in their offspring. In this study, we surveyed 2888 children of Chinese descent in China and Hong Kong to determine the relationship between the refractive state of parents and their children. The age range of the children was 7-17 years. Refraction was measured using a Canon R-22 objective infrared autorefractor and a survey on family history of ametropia was conducted using a questionnaire. We found that children with myopic parents are more likely to be myopic.

Adolescent↗
PubMed1993

[The influence of prostate-specific antigen p30 on human fertility].

The influence of prostate-specific antigen p30 on human fertility was studied with purified p30, domestic anti-p30 monoclonal and polyclonal antibodies. The results showed that the anti-p30 antibody presented in human serum had no negative effect upon human fertility and the anti-p30 antibody produced by heteroimmunization did not interfere with the process of human fertility in vitro. All these imply that it is unsuitable to recommend p30 as a contraceptive vaccine antigen.

Contraception, Immunologic↗
PubMed1993

[Genetic polymorphism of inter-alpha-trypsin-inhibitor (ITI) in a Han population in China].

Phenotypes of inter-alpha-trypsin-inhibitor (ITI) have been determined by isoelectric focusing on the polyacrylamide gel followed by immunofixation. The phenotype frequencies of ITI in the Han population in Chengdu, China were investigated using this method. In addition, family studies have been conducted in 21 families. The results showed that the ITI was polymorphic in the Han population in Chengdu. The allele frequencies were as follows: ITI*1 = 0.5763, ITI*2 = 0.4107, ITI*3 = 0.0130. It was obvious that the ITI is a new and promising genetic marker which can be used in the field of forensic haematogenetics.

Alpha-Globulins↗
PubMed1993

A study of the genetic polymorphism of human inter-alpha-trypsin-inhibitor (ITI) in the Han population, Chengdu, China.

Phenotypes of inter-alpha-trypsin-inhibitor (ITI) have been determined by isoelectric focusing on polyacrylamide gels followed by immunofixation. The phenotype frequencies of ITI in the Han population in Chengdu, P.R. China have been investigated using this method. In addition, family studies have been conducted in 21 families. The results show that ITI is polymorphic in the Han population in Chengdu, China. The allele frequencies are as follows: ITI*1 = 0.5763. ITI*2 = 0.4107, ITI*3 = 0.0130. ITI is thus a new and promising genetic marker that can be used in the field of forensic haematogenetics.

Alpha-Globulins↗
PubMed1993

Directional sensitivity of inferior collicular neurons of the big brown bat, Eptesicus fuscus, to sounds delivered from selected horizontal and vertical angles.

Under free field stimulation conditions, directional sensitivity of 336 inferior collicular (IC) neurons of 6 Eptesicus fuscus was studied by recording the minimum threshold (MT) and number of impulses of each neuron to a best frequency (BF) sound delivered from selected horizontal and vertical angles. An auditory response center was determined for each neuron by delivering a BF sound from a specific point of the bat's frontal auditory space. At the response center, the neuron had maximal directional sensitivity and lowest MT. Auditory response centers of all 336 IC neurons studied were located in the contralateral frontal auditory space and they shifted from lateral angles toward the midline with increasing BF. Sound direction affected the sharpness of frequency tuning (i.e. Q10-dB value) but not the BF and overall shape of the frequency threshold curve of a neuron. Sound direction also affected the MTs, number of impulses and intensity-rate functions but not the discharge patterns of IC neurons. High BF neurons generally had sharper directional sensitivity than low BF neurons. Bending downward the pinna contralateral to the recording site increased a neuron's MT and shifted its response center downward and toward the midline of the bat's frontal auditory space. The effect of pinna bending on a neuron's MT and impulse directional curves can be explained on the basis of variation of its auditory response area and its MT.

Acoustic Stimulation↗
PubMed1993

[Subtyping of GC globulin in human semen stain].

The group-specific component (GC) is an alpha 2 globulin with high genetic polymorphism in serum. There is also a little amount of GC in human semen. Pflug and Potsch-Schneider independently carried out GC subtyping of human semen stain with immobilized pH gradient gel isoelectric focusing (IPGIF) followed by ELISA in 1988. We report a new method there to subtype GC in human semen stains. First, the GC globulin was separated by polyacrylamide gel isoelectric focusing with pH 4.2-4.9 Pharmalyte. Then, it was immunoblotted to cellulose acetate membranes. Finally, the protein bands were shown by ELISA using horseradish peroxidase-linked secondary antibody system. All the 17 semen stains of volunteers were subtyped successfully. This method is easy to learn and convenient for applying in case work.

Enzyme-Linked Immunosorbent Assay↗