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J Q Tang

Publications and source records attributed to J Q Tang.

12 recordsLinked to original sources
PubMed2001

[A multiple-channel system for synchronous acquisition and analysis of neural electrophysiological signals].

The technique for synchronous electrophysiological recording from multiple single cells has been widely applied, but there is still a shortage of suitable data acquisition and analysis systems to fit electrophysiological equipment made in China or Japan. Recently we have developed an acquisition and analysis system for multiple-channel electrophysiological recording. In this paper, we present the pivotal technique of the system and some examples of applications.

Animals↗
PubMed1996

Overall informativity, OI, in DNA polymorphisms revealed by inter-Alu PCR: detection of genomic rearrangements.

We studied two systems of multilocus markers revealed by PCR using primers directing amplification between Alu repeats in a tail-to-tail orientation. Genomic polymorphisms were detected as the presence or absence of the electrophoretic bands representing DNA fragments of a given length. A total of 104 such fragments segregating as Mendelian markers in a panel of eight CEPH families were analyzed by two-point linkage analysis. Fifty-one of these fragments were localized with respect to CEPH markers; they represented 33 loci, 7 of which were multiallelic. Locus-specific oligonucleotides were developed and used as hybridization probes to identify the mapped loci within a complex pattern of inter-Alu PCR products. A great proportion of inter-Alu PCR polymorphisms represented length variants within amplified DNA segments, while others were presumably due to mutations within the priming sites. To describe the expected number of informative loci per typing experiment we introduced a parameter called overall informativity (OI), which provides a single measure of the multiplex ratio and the informativity of markers contributing to a multilocus system (OI of a single locus is equivalent to its heterozygosity and cannot exceed 0.5 for a biallelic codominant marker). High OI values (5.8 and 11.5) of the two presented systems of inter-Alu PCR markers of random chromosomal distribution render them suitable for mapping genomic rearrangements such as genomic deletions in tumoral tissues. This was illustrated by the detection of loss of heterozygosity in the 9q22-qter region in sporadic colon cancer.

Animals↗
PubMed1995

Alu-PCR combined with non-Alu primers reveals multiple polymorphic loci.

A marker suitable for genetic mapping and genomic fingerprinting is characterized by high polymorphic information content (PIC) and high "multiplex ratio" (defined as the number of loci that can be simultaneously typed). Towards this goal, we combined an Alu-specific with a non-Alu primer in a single PCR amplification targeting genomic regions where length polymorphisms are abundant. Three loci were revealed with the variable number of (AAT), (TAAA), (AG), and/or (AAAGG) motifs, and PIC values between 0.7 and > 0.94. Their location on Chromosomes (Chrs) 19q12, 17q12-q24, and 5q31.2-33.3 was determined by multipoint analysis with markers from CEPH database. The most common genotype for this three-locus marker, estimated from the occurrence of the most frequent alleles, is of the order of 2 x 10(-4), while the combined PIC value of a single typing experiment is 2.37. The use of a similar primer pair, as well as examples from the literature, indicates the general nature of this approach when a non-Alu oligonucleotide, presumably with "random" priming sites downstream of Alu repeats, is combined with an Alu-specific one. Clustering of DNA length variants in the regions adjacent to interspersed repeats provides opportunity to develop other highly informative multiple-locus markers similar to that described here.

Alleles↗
PubMed1991

Alternative rearrangements of immunoglobulin light chain genes in human leukemia.

Immunoglobulin heavy and light chain genes undergo rearrangement before they can be expressed by B-cells. A sequence of successive rearrangements has been proposed, suggesting that these events are initiated on heavy chain genes and are followed by sequential attempts of light chain gene rearrangements involving kappa gene alleles before lambda genes. This hypothesis, mainly established on B-cell clones of medullary origin, is consistent with the predominance of kappa chains among human serum immunoglobulins. However, data from tumors or normal lymphoid tissue suggest that lambda chain expression could be favored outside the bone marrow, due to an alternative rearrangement hierarchy. We investigated this hypothesis further on 17 leukemia samples. In three instances, we observed that lambda genes had undergone rearrangement while kappa genes remained in germline configuration. These data support the hypothesis of occasional alternative rearrangements of light chain genes.

Antigens, CD↗
PubMed1990

CD4-like molecules in human sperm.

The expression of a molecule recognized by CD4 monoclonal antibodies was investigated on human sperm using immunolabelling, biochemical and immunochemical methods. Flow cytometry detected a significant fluorescence signal. SDS-PAGE analysis and Western blotting identified a molecule of 60 kDa, consistent with a CD4-like structure as confirmed after selective immunoseparation. Additional bands reacting with anti-CD4 were found in sperm extracts (73 kDa) and seminal fluid (90 kDa). These data indicate that sperm express a molecule similar to the receptor for HIV described on mononuclear cells.

Antigens, CD↗
PubMed1990

A CD4-like molecule can be expressed in vivo in human parathyroid.

The expression of several epitopes of CD4, a molecule usually restricted to a subset of T-lymphocytes, was observed after immunofluorescent labeling of frozen-cut sections of human parathyroid. Seven samples obtained from three subjects presenting adenomas and from seven renal insufficiency patients with secondary or tertiary hyperplasia were found to express this molecule. Dot enzyme-linked immunosorbent assay, polyacrylamide gel electrophoresis, and Western blotting were used to characterize this peptide in cytosol and membrane fractions of these glands. These studies confirmed, in the parathyroids found positive in immunofluorescence, the presence of a protein with a mol wt similar to that of lymphocyte-derived CD4.

Adult↗
PubMed1989

Experimental study of free periosteal autograft. Animals age and periosteal osteogenesis.

This is a study of the correlation between the age of animals and the osteogenic potential of free periosteal autograft. The tibial periosteum of 27 rabbits, ranging in age from 4-104 weeks, was stripped and implanted into the quadriceps. Radiographic and histologic examination demonstrated that new bone was formed in both the young and adult rabbits. The morphologic basis and mechanism of bone formation of periosteum are discussed. Maintenance of integrity of the cambium layer of the periosteal graft is emphasized. Free periosteal graft of adult rabbits in the "resting" state can retain its osteogenic potential and produce new bone.

Aging↗
PubMed1989

Experimental study of free periosteal autograft. II. Increasing osteogenesis of periosteum.

The difference in osteogenesis of the periosteal graft and the effects of changing the recipient environment were studied in 26 young and 16 adult rabbits. The periosteal grafts from bilateral tibiae were implanted to the right and left sides of the abdominal wall, on the right side a coagulum was added. For quantitative examination, radionuclide, CT, ion-selective electrode, atomic absorption spectrometry and biochemical autoassay methods were used. The results showed that osteogenesis of periosteal grafts may increase by changing the local environments. The amount of periosteal bone formed in the adult rabbits was obviously less than in the young. The bone formation of the periosteal grafts with a coagulum, especially in the adults was increased. The possible mechanism of increasing periosteal osteogenesis by the coagulum is discussed.

Animals↗
PubMed1986

Etiologic and serologic investigations of the 1980 epidemic of dengue fever on Hainan Island, China.

Virologic and seroepidemiologic studies were carried out during an epidemic of dengue fever on Hainan Island in 1980. Dengue 3 virus was isolated from 46 of 77 acute phase sera and from 1 of 10 pools of adult Aedes aegypti. Dengue 1 virus virus was isolated from a single acute phase serum. Seroepidemiologic investigations showed that 74% of healthy individuals in the epidemic area had antibody to dengue virus compared to 54% in an area where epidemic dengue had occurred in 1978, and less than or equal to 8% in nonepidemic areas. There were no significant differences in antibody prevalence for different sex and age groups.

Aedes↗