PubMed Health⌕ Search

Biomedical subjects

W Q Zhang

Publications and source records attributed to W Q Zhang.

16 recordsLinked to original sources
PubMed1992

A 35 kDa Fos-related antigen is co-localized with substance P and dynorphin in striatal neurons.

The rat striatum after dopamine denervation followed by repeated apomorphine treatment was examined for the co-expression of c-fos and Fos-related antigens with dynorphin, substance P and [Met5]enkephalin using Western blot and immunohistochemical techniques. Administration of apomorphine, a dopamine agonist, elevated the level of 35 kDa Fos-related antigen which co-localized with dynorphin and substance P, but not enkephalin, in striatal neurons.

Animals↗
PubMed1992

Apomorphine induction of AP-1 DNA binding in the rat striatum after dopamine depletion.

The expression of AP-1 transcription factors was assessed in the dopamine-depleted rat striatum over a 1 week period of repeated apomorphine injections. A single injection of apomorphine increased the expression of a 35 kDa Fos-related antigen and Jun proteins and their expression continued to increase until day 3 of repeated apomorphine treatment in dopamine-depleted striata. Apomorphine induces AP-1 transcription factors which may be involved in modulating gene expression in the striatum.

Animals↗
PubMed1991

Extracellular concentrations of amino acid transmitters in ventral hippocampus during and after the development of kindling.

This study examined the possible involvement of amino acid release from ventral hippocampus in the establishment and maintenance of kindling in rats. Release of amino acids from ventral hippocampus was measured by microdialysis coupled with high-performance liquid chromatography. Samples were obtained by microdialysis perfusion of freely moving animals receiving deep prepiriform cortex (DPC) electrical stimulation. Samples of perfusate were collected before, during and after kindling was established. DPC kindling stimulation significantly increased concentrations of glutamate (Glu) and glycine (Gly) in perfusate from ventral hippocampus during kindling. Increased basal release of Glu was evident up to 30 days after the last electrical stimulation. We conclude that release of Glu and Gly in the ventral hippocampus may play an important role during establishment, but not in maintenance of kindling.

Amino Acids↗
PubMed1991

Decreased glutamate release correlates with elevated dynorphin content in the hippocampus of aged rats with spatial learning deficits.

The effects of aging on extracellular glutamate and tissue dynorphin content in the hippocampus were examined in Fischer-344 rats. Young adult (4-month-old) and aged (24-month-old) rats were trained to find a hidden platform in the Morris water task. Aged rats were unable to acquire the spatial learning task as rapidly as young controls. Following behavioral testing, an in vivo microdialysis perfusion method was used to determine extracellular glutamate levels in the hippocampus. There was a 25-35% reduction in extracellular glutamate concentration in both dorsal and ventral hippocampus of aged rats compared to young rats, in the absence of any change in tissue glutamate levels. Radioimmunoassay showed an increase in dynorphin A(1-8)-like immunoreactivity [DYN-A(1-8)LI] in both dorsal and ventral hippocampus, but not striatum, of aged rats. Immunocytochemistry indicated that this increase was localized to the dentate granule cells and mossy fibers. Furthermore, among the aged rats the increase in DYN-A(1-8)LI was inversely correlated with the decrease in extracellular glutamate. These results suggest that the disregulation of dynorphin observed in cognitively impaired aged rats is related to reduced excitatory transmission within the hippocampal formation.

Aging↗
PubMed1991

Detection of blood stage antigens of Plasmodium vivax by sandwich ELISA using pan-species monoclonal antibodies and polyclonal antibodies.

This paper reports an improved PcAb-McAb-ELISA test to detect blood stage Plasmodium vivax antigen in which the plates were coated with rabbit anti-P. cynomolgi polyclonal antibody to capture the antigens in test samples and two monoclonal antibodies, M26-32 and 3F9, were added together to react with the captured antigens. The coincidence rate with this test was 93% with microscopically confirmed P. vivax cases, 97% with normal samples, 95% with microscopically negative fever cases from nonendemic areas and 86% from endemic areas, respectively. The sensitivity was greater than 1 parasite/10(5) RBC.

Antibodies↗
PubMed1990

Alterations in acetylcholine-induced stimulation of inositol phospholipid hydrolysis in the dorsal hippocampus of kindled rats.

Agonist-induced turnover or release of inositolphosphates (IP) was studied in the dorsal and the ventral hippocampus 24 h, 1 month, and 3 months after the last electrical stimulus of kindled rats. A significant increase in acetylcholine (ACh)-stimulated IP turnover was observed in dorsal, but not ventral, hippocampus 24 h and 1 month after the last electrical stimulus. However, this effect was not evident 3 months after kindling. The excitatory amino acids (quisqualic acid and ibotenic acid) at the concentrations used, however, failed to produce any change in receptor-stimulated release or turnover of IP. Thus the changes in ACh-induced IP release, although long-term, are not permanent and do not appear to be released to the neurobiological alterations associated with the long-term maintenance of the kindling phenomenon.

Acetylcholine↗
PubMed1990

Systemic administration of kainic acid increases GABA levels in perfusate from the hippocampus of rats in vivo.

The ventral hippocampi of male, Fischer-344 rats were implanted with microdialysis probes and the effects of systemically administered kainic acid (KA) (8 mg/kg, s.c.) on the in vivo release of amino acids were measured for four hours after administration. In order to measure GABA release in vivo, gamma-vinyl-GABA (GVG), an irreversible inhibitor of GABA transaminase, was injected intrahippocampally prior to perfusion. GVG pretreatment resulted in measurable levels of GABA in the perfusate without significant effects on the release of aspartate, glutamate, glutamine, glycine or taurine. Following GVG pretreatment systemic administration of KA produced a time-dependent increase in GABA, as well as all other amino acids except glutamine, which was initially decreased. These results show for the first time that systemically administered KA increases extracellular GABA levels, an effect previously reported only in vitro. These data suggest that prior to destruction of GABA-containing interneurons in the hippocampus, there is an increased activity of those GABA interneurons reflected as an increase in extracellular GABA levels.

Amino Acids↗
PubMed1990

Technology of the divalent engineered diarrhea vaccine (K88, K99) production by high cell density fermentation and the antigen overexpression.

This paper describes the production of divalent K88, K99 antigens by high cell density fermentation and gene overexpression. The cell density reached above 40 at A600nm and the antigens were at 2(12) level. The thousands dosage of the vaccine can be made by using 10 I broth of the fermentation. The stability of the plasmid showed that about 30 percent of the bacteria lost its plasmid after 20 h fermentation. It was found that the antigens were overexpressed and located in both the pili of E. coli and in the medium in equal quantities. It means that the expression and regulation of the genes of K88, K99 may be different from the wild type of enterotoxingenic E. coli. A large number of the vaccinated pregnant sow showed that the piglets were effectively protected from the infection of enterotoxingenic E. coli. The results indicated that the large quantities requirement of the vaccine could be provided by using a small fermenter. This vaccine consists of two forms of the antigen K88, K99 which, when present in the pili as well as the medium, is more favorable to stimulate the production of antibody in the colostrum of pregnant sow.

Animals↗
PubMed1988

Increased dopamine release from striata of rats after unilateral nigrostriatal bundle damage.

Dopaminergic control of striatal neurons is retained in rats sustaining lesions of the nigrostriatal bundle (NSB) as long as 10% of the projection remains, suggesting that enhanced efficiency of dopamine (DA) transmission may compensate for the denervation of the striatum. To examine this hypothesis we have studied the extracellular concentration of striatal DA using brain dialysis. In control rats, haloperidol (1 mg/kg, i.p.) or depolarization of striatal tissue with 25 mM KCl increased, and gamma-butyrolactone (500 mg/kg, i.p.) decreased DA and homovanillic acid (HVA) levels in striatal dialysates. Three weeks after unilateral injection of 6-hydroxydopamine (6-OHDA) to substantia nigra, DA content in the ipsilateral striatum was decreased by 60-98%. Nevertheless, extracellular DA concentration in the lesioned striata remained unchanged in rats with 60-90% DA depletions. More extensive lesions (96% DA depletion) were accompanied by 60% reduction in DA release. In contrast, extracellular HVA levels in the lesioned striata decreased proportionally to the depletion of tissue DA, indicating decreased inactivation of extracellular DA. We propose that the capacity of the residual DA terminals to maintain normal levels of extracellular DA after 60-90% NSB lesions may serve to compensate for the partial denervation of the striatal tissue. Disruption of striatal DA functions and postsynaptic supersensitivity after more extensive lesions may be associated with the failure of the NSB to fully compensate for loss of DA terminals. In striata contralateral to the 6-OHDA lesions, increased DA release was also observed. In addition, 60-90% ipsilateral DA depletions were accompanied by 32% and 42% increases in DA and HVA content in contralateral tissue, respectively. The possibility of the contralateral sprouting of DA terminals is discussed.

4-Butyrolactone↗