An alternative linker-mediated polymerase chain reaction method using a dideoxynucleotide to reduce amplification background.
Explore the source record for details and available documents.
Animals↗
Biomedical subjects
Z Gong
Publications and source records attributed to Z Gong.
Effect of chelation with meso-dimercaptosuccinic acid (DMSA) before and after the appearance of lead-induced neurotoxicity in the rat.
This paper examines whether a chelating agent (DMSA) can prevent and reverse the effects of lead (Pb) as evidenced by changes in brain glial fibrillary acidic protein (GFAP) concentration and in the habituation pattern of rearing behavior. Male F344 rats (42 days old) received Pb acetate at 150 or 2000 ppm as Pb in their drinking water for 21 days and returned to regular water for another 21 days to observe recovery. Blood Pb (BPb) concentration rose to 37 and 82 microg/dl for 150 and 2000 ppm, respectively. Rats exposed to 150 ppm Pb exhibited changes in GFAP concentration and behavioral hyperactivity, when placed in an unfamiliar cage. The 2000 ppm Pb exposure caused greater changes in GFAP, but behavioral hyperactivity appeared only postexposure, when BPb was declining. Chelation (DMSA, 50 mg/kg po, 3 times/week for 21 days) decreased the BPb concentration, and prevented and reversed the Pb-induced changes in GFAP and rearing, but not in body weight. Administration of DMSA by itself for 21 days caused no untoward effects in brain GFAP, behavior, or body weight. Concurrent administration of DMSA and Pb resulted in no evidence of additive toxicity. Results indicate that: (1) A brief behavioral test of habituation is a sensitive index of neurotoxicity and chelating therapy; (2) Pb-induced hyperactivity depends upon BPb concentration regardless of whether activity is measured during or after exposure; (3) repeated treatment with DMSA is effective in reducing Pb neurotoxicity; (4) there was no evidence that DMSA enhanced the absorption of Pb. The finding that DMSA administered late in exposure can hasten the recovery of toxic signs suggests that extracellular Pb continues to play a significant role even after toxic signs have appeared.
Animals↗
Cloning and molecular analysis of structural genes involved in anthocyanin biosynthesis and expressed in a forma-specific manner in Perilla frutescens.
Two cultivars of Perilla frutescens, red and green formas are known to differ in anthocyanin accumulation in leaves and stems. cDNA clones encoding the enzymes involved in anthocyanin biosynthesis, chalcone synthase (CHS), flavanone 3-hydroxylase (F3H), dihydroflavonol 4-reductase (DFR), and UDP glucose: flavonoid 3-O-glucosyltransferase (3GT), were isolated from cDNA libraries derived from the leaves of a red forma of P. frutescens by screening with partial fragments amplified by means of polymerase chain reaction (PCR) and heterologous cDNAs as probes. The deduced amino acid sequences of these four genes exhibited 40-90% identity with those reported for the corresponding gene from other unrelated species. Southern blot analysis for these genes and two other structural genes, the leucoanthocyanidin dioxygenase (LDOX, anthocyanidin synthase) and anthocyanin acyltransferase (AAT) genes, indicated that each gene comprises a small multi-gene family. More than three copies of the CHS gene are present, two copies of the other genes being present. The expression of five genes, the exception being the CHS gene, was detected only in red leaves of the red forma of P. frutescens, i.e. not in green leaves of the green forma plant. The CHS gene was expressed in both red and green leaves, but 10-fold more in red leaves than in green leaves. These results suggest that the expression of all structural genes examined is coordinately regulated in a forma-specific manner. Under weak-light conditions, the accumulation of both anthocyanin and mRNAs of biosynthetic enzymes was lower in leaves of the red forma. High-intensity white light coordinately induced the accumulation of transcripts of all six genes examined in the mature leaves of red P. frutescens.
Acyltransferases↗
Optosensor for cinchona alkaloids with C18 silica gel as a substrate.
A flow-through optosensor for cinchona alkaloids with C18 silica gel as a substrate is proposed. The sensor is developed in conjunction with a flow-injection analysis system and is based on the retention of the cinchona alkaloids on a C18 column and the enhancement of their fluorescence. The analytical performance characteristics of the proposed sensor for the detection and quantification of these alkaloids were as follows: the detection limits of quinine, cinchonine, quinidine and cinchonidine were 2.3, 31.6, 2.3 and 31.6 ng ml-1, respectively, with relative standard deviations of 0.9% for quinine and quinidine (20 ng ml-1, n = 7) and 1.1% for cinchonine and cinchonidine (4.0 micrograms ml-1, n =7), respectively. Most of the common species did not interfere. The recommended method has been successfully tested for determination of quinine in pharmaceutical preparations and soft drinks.
Beverages↗
Transgenic Arabidopsis lines expressing gene VI from cauliflower mosaic virus variants exhibit a range of symptom-like phenotypes and accumulate inclusion bodies.
Gene VI of cauliflower mosaic virus (CaMV) is an important determinant of symptom expression during infection. We have constructed a series of transgenic Arabidopsis lines that express gene VI protein (P6) from two CaMV isolates (Bari-1 and Cabb B-JI) that cause mild and severe symptoms, respectively, in Arabidopsis, and from a recombinant virus (Baji-31) with a hybrid gene VI that causes very severe symptoms. From 41 transgenic lines analyzed, 17 showed symptom-like phenotypes that ranged from mild vein chlorosis to severe chlorosis and stunting. P6 levels in transgenic lines varied from undetectable in the lowest expressors to levels greater than those in CaMV-infected plants. There was a strong correlation between phenotype severity and the level of P6, and with the gene VI origin in the order, Baji-31 > B-JI > Bari-1. This was similar to symptom severity in Arabidopsis infected with the respective CaMV variant. We also found that transgenic P6 accumulated in inclusion bodies that were similar to those found in infected plants but lacking virions. We conclude that expression of P6, in the absence of virus replication, elicits a subset of the host symptom responses normally observed during infection and that the level, sequence, and possibly the form of P6 are important in potentiating the process.
Arabidopsis↗
Sequencing of 3' cDNA clones using anchored oligo(dT) primers.
Explore the source record for details and available documents.
Animals↗
An abundant zebrafish cDNA clone encodes a ras-like protein which is expressed ubiquitously.
An abundant clone from a zebrafish embryonic cDNA library was identified and sequenced. It encodes a ras-like protein, being 94-95% identical to vertebrate Ran, ras-related nuclear protein. The zebrafish Ran mRNA is expressed in all tissues examined and throughout embryogenesis; therefore, it is likely that the Ran protein functions in all types of cells.
Amino Acid Sequence↗
[Determination of Ni, Al, Mn and Si in copper based alloy by high current and microsecond pulsed glow discharge optical emission spectrometry].
The determination of Ni, Al, Mn and Si in copper based alloy by high current and microsecond pulsed (HCMSP) glow discharge optical emission spectrometry (GD-OES) has been reported. With the laboratory built experiment set-up, the factors effecting analytical performance have been studied. The results of sample analysis are in good agreements with the recommendation values, and the stansard deviation for six determinations were 2.66% for Ni, 2.17% for Mn, 6.02% for Si, 1.00% for Al respectively.
English Abstract↗
[Enhanced emission spectra of Yb, Eu, Y and Sm HCLS with high current microsecond pulsed supply].
The emission spectra of Yb, Eu, Y, Sm hollow cathode lamps have been investigated with a high current microsecond pulsed (HCMP) supply developed in our laboratory. Both atomic and ionic emission lines of interest of these rare earth elements are enhanced by tens to tens of thousand times in HCMP mode compared to DC mode. Effects of parameters of the supply on emission intensities are surveyed. HCMP HCLs may be used as an economic and convenient excitation source for atomic/ionic fluorescence spectrometric analysis.
English Abstract↗
[Progress in determination of rare earths by atomic/ionic fluorescence spectrometry].
The progress of determination of rare earths by atomic/ionic fluorescence spectrometry is reviewed. The experimental systems and the analytical characteristics of the technique are briefly discussed, and its applications are illustrated in detail. The research trends are predicted as well. The systems with appropriate combinations of excitation sources and atomization/ionization cells are well proved to increase analytical sensitivity and minimize interferences. For the excitation soures, hollow cathode lamp has been proved to be economic and practical, although pulsed dye laser has been intensively investigated. The inductively oupled plasma is a preferable atomization/ionization cell. The atomic/ionic fluorescene spectrometry is one of effective techniques for the determination of rare earths mainly due to its low spectral interference and wide linear dynamic range.
English Abstract↗
Intraoperative transesophageal echocardiography using high-resolution biplane 7.5 MHz probes with continuous-wave Doppler capability in infants and children with tetralogy of Fallot.
This study reports the role of biplane transesophageal echocardiography in monitoring surgical repairs of tetralogy of Fallot. In our patients, 3 repairs were revised based on transesophageal echocardiography and continuous-wave Doppler results, and intraoperative management was altered in 2 others.
Adolescent↗
Skin antifreeze protein genes of the winter flounder, Pleuronectes americanus, encode distinct and active polypeptides without the secretory signal and prosequences.
Distinct antifreeze polypeptides (AFP) were isolated from the skin of the winter flounder, Pleuronectes americanus, by gel filtration and reverse phase high performance liquid chromatography. In parallel, several cDNA clones were isolated from a skin cDNA library using a liver AFP cDNA probe. Both protein and DNA sequence analyses indicate that flounder skin contains several distinct but homologous alanine-rich AFPs. Although the skin type AFPs contain 11 similar amino acid repeats found in the secretory liver type AFPs, the skin type AFPs are mature polypeptides lacking both the signal and prosequences, indicating that they may function intracellularly. The skin type AFP is significantly less active in thermal hysteretic activity than the liver type AFP. Genomic Southern analysis indicates that like the liver type AFP genes, there are multiple copies (30-40 copies) of skin type AFP. Although the liver type AFP genes are specifically expressed in the liver and to a lesser extent in intestine, the skin type AFP genes are expressed in all tissues examined including the liver and abundantly in exterior tissues, i.e. skin, scales, fin, and gills, suggesting an important protecting role in these exterior tissues.
Alanine↗
Lead-induced alterations of glial fibrillary acidic protein (GFAP) in the developing rat brain.
The developing nervous system is preferentially vulnerable to lead exposure with alterations in neuronal and glial cells of the brain. The present study examined early lead-induced alterations in the developing astrocyte population by examination of the developmentally regulated astrocyte specific protein, glial fibrillary acidic protein (GFAP). A developmental profile (Postnatal Day (PND) 6, 9, 12, 15, 20, and 25) for GFAP mRNA was generated for the cortex and hippocampus of developing Long-Evans hooded male rats under various lead exposure conditions: (1) prenatal (Gestational Day 13 to birth), (2) postnatal (Postnatal Day 1 to Postnatal Day 20), or (3) perinatal (Gestational Day 13 to Postnatal Day 20) exposure to lead acetate (0.2% in the drinking water of the dam). Control GFAP mRNA levels displayed a developmentally regulated profile of expression. In the cortex this was characterized by a transient elevation in peak level between PND 9 and PND 15 followed by a decline to within adult levels by PND 25. Under all lead acetate exposure conditions, the cortex showed an increase in the peak level of expression and extended the time of elevation of GFAP mRNA until PND 20. Levels of GFAP were elevated at PND 60 but not as early as PND 28. In the control hippocampus, levels of GFAP mRNA gradually increased until PND 20 followed by a sharp decline at PND 25. Postnatal and perinatal lead exposure followed a similar pattern; however, levels declined earlier at PND 20. Following prenatal lead exposure, levels of GFAP mRNA showed an earlier peak at PND 12 and a decrease as early as PND 15. By PND 60 protein level for GFAP was elevated in the postnatal lead exposure group only. As demonstrated by GFAP immunoreactivity, these lead-induced elevations were not associated with astrocyte hypertrophy. Following a physical injury in the cortex, astrocyte reactivity was similar between lead-exposed and control rats. These data suggest an alteration in the timing of astrocyte differentiation and maturation in the brain following developmental lead exposure.
Analysis of Variance↗
MRX 115, an echocardiographic contrast agent, produces myocardial opacification after intravenous injection in primates: studies before and after occlusion of left anterior descending coronary artery.
Explore the source record for details and available documents.
Animals↗
[A study on AIDS-related knowledge, attitude and behavior in servicemen in China].
AIDS-related knowledge, attitude and behavior were studied in 1,058 servicemen in China with self-administered and anonymous questionnaires. Results showed 76.7% to 89.5% of the servicemen surveyed knew correctly the risk of AIDS and its route of transmission, but only 8.5% of them answered all the questions listed in the questionnaire correctly. Source of their knowledge about AIDS was mainly from newspapers, magazines and extracurricular books. Most of them thought they could have very little, or no chance to contract the illness. There were 74.0% of the servicemen eager to get knowledge about AIDS and 83.2% would like to accept relevant testing. And, 80.2% of them answered that they could put their behavior under control, or change their unhealthy one to prevent from the illness. It indicated that comprehensive and correct publicity and education could play an active role in the prevention of HIV infection.
Acquired Immunodeficiency Syndrome↗
Exposure to methyl mercury results in serum autoantibodies to neurotypic and gliotypic proteins.
Environmental exposure to methyl mercury (MeHg) continues to pose a threat to humans, making early detection of neurotoxic effects a pressing concern. An enzyme-linked immunosorbent assay (ELISA) to measure serum autoantibodies (Ig) to neurotypic and gliotypic proteins [neurofilament triplet (NF68; NF160; NF200), myelin basic protein (MBP) and glial fibrillary acid protein (GFAP)] as markers of subclinical neurotoxicity was developed and tested in Fisher 344 rats exposed orally to 16 or 32 ppm MeHg. Both levels of MeHg resulted in serum Ig to all 5 proteins, not normally seen in controls. For anti-NFs and anti-GFAP, IgM isotype predominated significantly (p < 0.05) over IgG.Ig for MBP were of the IgG isotype, IgM were not detected. Significant differences (p < 0.05) between 16 and 32 ppm MeHg in levels of anti-NF 68 and GFAP, IgM, were evident at 7 days of exposure, but not at 14 days. Anti-NF 160, IgM, was significantly (p < 0.01) elevated in rats exposed to 32 ppm vs 16 ppm at 14 days. However, at both dose levels anti-NF 68 titers were the most elevated of the three NF proteins (p < 0.0001). For anti-NF 200 and anti-MBP it was the IgG isotype that was significantly (p < 0.01) elevated in the 32 ppm group at 7 days. GFAP levels as a marker of neurotoxicity were determined in the cortex, hippocampus and cerebellum. Exposure to 32ppm MeHg resulted in decreased (p < 0.05) levels in the cortex at 14 days. Both levels of MeHg resulted in increased GFAP in the cerebellum at 14 days. This study suggests that assay of autoantibodies against nervous system proteins may provide a means of assessing the early neurotoxic effects of environmental MeHg exposure.
Animals↗
Exposure to methylmercury results in serum autoantibodies to neurotypic and gliotypic proteins.
Environmental exposure to methylmercury (MeHg) continues to pose a threat to humans, making early detection of neurotoxic effects a pressing concern. An enzyme-linked immunosorbent assay (ELISA) to measure serum autoantibodies (lg) to neurotypic and gliotypic proteins [neurofilament triplet (NF68; NF160; NF200), myelin basic protein (MBP) and glial fibrillary acid protein (GFAP)] as markers of subclinical neurotoxicity was developed and tested in Fisher 344 rats exposed orally to 16 or 32 ppm MeHg. Both levels of MeHg resulted in serum lg to all 5 proteins, not normally seen in controls. For anti-NFs and anti-GFAP, lgM isotype predominated significantly (p < 0.05) over lgG. lg for MBP were of the lgG isotype, lgM were not detected. Significant differences (p < 0.05) between 16 and 32 ppm MeHg in levels of anti-NF 68 and GFAP, lgM, were evident at 7 days of exposure, but not at 14 days. Anti-NF 160, lgM, was significantly (p < 0.01) elevated in rats exposed to 32 ppm vs 16 ppm at 14 days. However, at both dose levels anti-NF 68 titers were the most elevated of the three NF proteins (p < 0.0001). For anti-NF 200 and anti-MBP it was the lgG isotype that was significantly (p < 0.01) elevated in the 32 ppm group at 7 days. GFAP levels as a marker of neurotoxicity were determined in the cortex, hippocampus and cerebellum. Exposure to 32ppm MeHg resulted in decreased (p < 0.05) levels in the cortex at 14 days. Both levels of MeHg resulted in increased GFAP in the cerebellum at 14 days. This study suggests that assay of autoantibodies against nervous system proteins may provide a means of assessing the early neurotoxic effects of environmental MeHg exposure.
Animals↗
[Clinical significance of c-erbB2 oncoprotein expression in stomach carcinoma].
This paper reports a study of the c-erbB2 oncoprotein (by immunohistochemical method) in 97 gastric carcinoma resected at Shanghai Cancer Hospital in 1991. In 30 out of the 97 cases (30.9%) c-erbB2 was positive and its expression was higher among patients with lymph node metastasis (P < 0.05). Univariate and multivariate analyses indicated that c-erbB2 expression betokened poor prognosis.
Adenocarcinoma↗