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Biomedical subjects

H Zhao

Publications and source records attributed to H Zhao.

At least 145 records · Page 8Linked to original sources
PubMed2001

[Mutagenic activity of organic pollutants extracted from waters in Guanting Reservoir and Yongding River].

Water samples collected from Guanting Reservoir and Yongding River in July 1999 were examined by Ames test to evaluate the mutagenic activity of organic pollutants. The samples have been concentrated by using XAD-2 resin filled columns. In the test with strain TA98, direct mutagenic effects (-S9) were observed in water extracted from Bridge No.8 and Yanchi at the dosage of 0.8 L/plate, indicating the existence of direct frame shift mutagens. The mutagenic effects disappeared after addition of S9, indicating no pro-mutagen in the samples. In the test with strain TA100, direct base pair substitute mutagenic effect was observed only in the sample from Bridge No. 8 at the dosage of 0.4 L/plate. When adding S9, suspicious positive reaction could exist at the dosage of 0.8 L/plate. The results demonstrated that the water in Yongding River has been heavily polluted by mutagens, for which further studies should be carried out to identify the sources and types of these mutagens.

Animals↗
PubMed2001

[Experimental study on effect of xinkang oral liquid on coxsackie B3 viral myocarditis in mice].

OBJECTIVE: To study the therapeutic effect of Xinkang Oral Liquid (XKOL) in treating acute Coxsackie B3 viral myocarditis in mice. METHODS: Viral myocarditis model was established by intraperitoneal inoculation with Coxsackie B3 virus. Mice were randomly divided into 4 groups randomly, the model group, the positive control group (treated with Ribavilin), the XKOL group and the normal control group. Body weight of mice was weighed at the 5th, 10th and 20th day. Weight, macro- and histopathologic changes of heart were observed by microscope and measured by morphometric quantification, and the data were treated statistically. RESULTS: In the XKOL group, the body weight of mice increased, the degree of myocardial necrosis mild and small in size, which has been repaired more completely, the antiviral effect was found in XKOL group. CONCLUSION: XKOL has definite therapeutic effect on viral myocarditis, its effect is better than Ribavilin in protecting myocardium and anti-virus.

Animals↗
PubMed2001

[Modulatory effect of orphanin FQ on the IL-1beta transcripts in hippocampus].

Using in situ hybridization and immuno-fluorescent double labeling method, we investigated the function of orphanin FQ on interlenkin-lbeta (IL-lbeta) transcripts in hippocampus. Intracerebroventricularly (icv) administrated IL-lbeta antibody reduced IL-l and TNF-alpha secreted from peritoneal macrophage. The high level of IL-lbeta transcript in hippocampus elicited by traumatic stress was blocked by icv injection of orphanin FQ (0.55 nmol), which was reversed by orphanin FQ receptor antagonist ([phe(1)Psi(CH(2)-NH)Gly(2)] nociceptin-(1-l3)-NH(2)). Opioid receptor-like receptor transcripts were found in neuron, astrocyte and microglia. Based on the results, we conclude that orphanin FQ functions as a neuroimmune modulator, and provokes immune response via mediation of IL-lbeta derived from neuron, astrocyte and microglia in hippocampus.

Adjuvants, Immunologic↗
PubMed2001

[The effects of leptin on proliferation and function of human osteoblast].

OBJECTIVE: To observe the effect of leptin on osteoblast. METHODS: Human osteoblast primary culture was carried out, and the morphology and function of osteoblast were observed. The effects of different levels of leptin on osteoblast in different days were assessed by MTT colorimetry. Osteocalcin production was measured also. RESULTS: Human osteoblasts were fusiform in shape and were positive for alkaline phosphatase by histochemical staining, positive for osteocalcin by immunofluorescence staining, and positive by Alizarin Reds staining after mineralized upon supplementation with ascorbate and beta-glycerophosphate. On the first, second and third days, the proliferation of osteoblast, cultured with different concentrations of leptin, had no changes. The leptin-stimulated synthesis of osteocalcin of cells was found to be dose-dependent (P < 0.05), but not time-dependent (P > 0.05). CONCLUSION: The above data indicated that there were no evidences for the effects of leptin on the proliferation of human osteoblast, but leptin could enhance the function of human osteoblast.

Ascorbic Acid↗
PubMed2001

[Expression of bcl-2 in facial motoneurons and its ultrastructural localization following facial nerve injury].

OBJECTIVE: To explore the expression of bcl-2 in facial motoneurons and its subcellular distribution. METHODS: Wistar rats were used in this study. Facial nerve transection was performed at stylomastoid foramen or internal acoustic meatus. Facial nerve crush was made at stylomastiod foramen. The animal survived for 1, 3, 7, 15, 30 and 60 days respectively. Facial nucleus was treated with bcl-2 monoclonal antibody or bcl-2 DIG-labelling probe and studied with immunohistochemistry and in situ hybridization. The bcl-2 positive motoneuron was investigated with immuno-electron microscope. RESULTS: It was demonstrated that bcl-2 protein level was corresponded with bcl-2 mRNA expression. The level of bcl-2 expression in facial motoneurons was high in normal facial nerve. It increased on the first day and declined on the third day post-transection in facial motoneuron. It reached the lowest level on the 15th days following facial nerve injury (P < 0.05). The expression recovered to normal level in two months (P > 0.05). After facial nerve transected, the reduction of bcl-2 expression was more significant when facial nerve transected close to facial nucleus than that far from facial nucleus (P < 0.05). Comparing to facial nerve transection in stylomastoid foramen, there was more intensive bcl-2 expression following facial nerve crush (P < 0.05). Further study showed that bcl-2 primarily resided in the nuclear envelop, endoplasmic reticulum and mitochondrial membrane. CONCLUSIONS: These data indicated that high level bcl-2 protein may prevent facial motoneuron death following facial nerve injury. It is suggested that overexpression bcl-2 by transgene may prevent facial motoneurons death.

Animals↗
PubMed2001

[Rat hearing loss and hearing organs mitochondrial DNA4834 deletions associated with hypercholesteremia].

OBJECTIVE: To determine whether or not the rat hypercholesteremia contributes to hearing organs mtDNA4834 deletion and involves in the development of hearing loss. METHODS: The rat hypercholesteremia model (n = 38) was established by feeding with high cholesterol diet and the control group (n = 22) with common diet for 6 months. The rats were tested for auditory sensitivity using auditory brainstem response (ABR). Twenty-one left cochleae and 27 left cochlear nuclei from experimental group and 10 left cochleae and 13 left cochlear nuclei from control group were harvested. The total DNA of them was extracted. mtDNA was amplified by nest PCR to examine the presence of mtDNA4834 deletion. RESULTS: Our result showed: (1) There is a significant increase in serum cholesterol level and ABR threshold in the experimental group. (2) The mitochondrially-encoded tRNA and ND1 segments were amplified from all samples, as well as mtDNA4834 deletions. (3) The incidence of mtDNA4834 deletions in hearing organs of hypercholesteremia rats was significantly higher than that of the control group (P < 0.05). CONCLUSION: Extended hypercholesteremia can induce hearing loss, and mtDNA4834 deletion in hearing organs may be one of the pathogenic mechanisms.

Animals↗
PubMed2001

[Application of diapason instrumentation for treatment of unstable lumbosacral spinal stenosis].

OBJECTIVE: To observe the preliminary clinical outcome of using a new instrumentation Diapason system and to introduce the characterization and surgical technique of this new system for treatment of unstable lumbar spinal stenosis. METHODS: 16 patients with unstable spinal stenosis who were treated by decompression, posterolateral intertransverse arthrodesis and transpedicle instrumentation of Diapason system, were analyzed retrospectively. RESULTS: Lower back pain (LBP) of 16 patients were significantly alleviated after surgery (scores of LBP before operation: 47.5 +/- 0.8; scores of LBP after operation: 31.9 +/- 2.3, P < 0.001). There was no implant failure, no early or later infection and no neurological complications in 16 patients at an average of 6.2-month follow-ups. No pseudoarthrosis was observed on roentgenography. CONCLUSION: Our short-term follow-up and limited cases study showed satisfactory preliminary result of treating unstable lumbar spinal stenosis with Diapason internal fixation.

Adult↗
PubMed2001

Three-dimensional correction of scoliosis using TSRH instrumentation.

OBJECTIVE: To evaluate the results of TSRH instrumentation in the correction of coronal, sagittal and rotational deformity of scoliosis. METHODS: From January 1998 to December 1999, thirty-two consecutive patients (6 males, 26 females)with scoliosis underwent anterior or posterior spinal instrumentation and fusion using TSRH instrumentation. Of these cases, 21 were idiopathic scoliosis and 11 were congenital scoliosis. The average age at surgery was 16.4 years (range, 11 approximately 45 years). The mean Cobb angle at surgery was 71.2 degrees range, 44 degrees approximately 125 degrees) in the coronal plane, and 49. degrees range, 16 degrees aprroximately 67degrees in the sagittal plane. Rotational deformity (Nash-Moe) ranged from I to III degree. Preoperative apical translation averaged 4.8 cm (range, 3 approximately 9 cm). RESULTS: The average follow-up duration was 13.3 months (range, 10 approximately 24 months). At the final follow-up, the mean Cobb angle in the coronal plane was 26.6 (range, 10 degrees approximately 73 degrees), with a 63.8% of improvement. Sagittal alignment was well maintained with a mean Cobb angle of 28 degrees (range, 10 degrees approximatelky 45 degrees). The average correction of rotation of the apical vertebra was I degree. The average apical translation was 1.6 cm (range, 0.5 approximately 5.0 cm) representing a correction rate of 66, 7%. Complication was noted in two cases with an incidence of 3.1%, one case had superficial infection and the other one had lower hook dislocation. There was no neurologic deficit and pseudoarthrodesis in this series. CONCLUSION: TSRH instrumentation is an effective and convenient three-dimensional correction system with a lower rate of complication, which can not only correct the coronal and rotational deformity, but maintain the sagittal alignment as well.

Adolescent↗
PubMed2001

[IR characteristics of oxide].

In this paper the chief IR characteristics of oxide was summarized. The relationship between the IR characteristics of oxide and the structures of oxide was discussed. The results show that the organic compound and inorganic compound have great infrared activity, and have intense and wide absorption peaks. This provides the strong basis on which we can distinguish the oxide from the compound.

Inorganic Chemicals↗
PubMed2000

Activation of the transcription factor Oct-1 in response to DNA damage.

Mammalian cells exhibit complex cellular responses to genotoxic stress, including cell cycle checkpoint, DNA repair, and apoptosis. Inactivation of these important biological events will result in genomic instability and cell transformation. It has been demonstrated that gene activation is a critical initial step during the cellular response to DNA damage. A number of investigations have shown that transcription factors are involved in the regulation of stress-inducible genes. These transcription factors include p53, c-Myc, and AP-1 (c-fos and c-jun). However, the role for the octamer-binding transcription factor Oct-1 in the DNA damage-activated response is unknown. In this report, we have presented the novel observation that the transcription factor Oct-1 is induced after cells are exposed to multiple DNA-damaging agents and therapeutic agents, including UV radiation, methylmethane sulfonate, ionizing radiation, etoposide, cisplatin, and camptothecin. The induction of the Oct-1 protein is mediated through a posttranscriptional mechanism and does not require the normal cellular function of the tumor suppressor p53, indicating that the Oct-1 protein, as a transcription factor, may play a role in p53-independent gene activation. In addition to increased protein level, the activity of Oct-1 DNA binding to its specific consensus sequence is also enhanced by DNA damage. Therefore, these results have implicated that the transcription factor Oct-1 might participate in cellular response to DNA damage, particularly in p53-independent gene activation.

DNA Damage↗
PubMed2000

Immunochemical demonstration of a novel beta-subunit isoform of X, K-ATPase in human skeletal muscle.

Recently we have identified mRNA encoding a hitherto unknown mammalian X,K-ATPase beta-subunit expressed predominantly in muscle tissue (Pestov, N. B. et al. (1999) FEBS Lett. 456, 243-248). Here we demonstrate the existence of the predicted protein, designated as beta(m) (beta(muscle)), in human adult skeletal muscle membranes using immunoblotting with beta(m)-specific antibodies generated against recombinant polypeptide formed by extramembrane beta(m) domains. The electrophoretic mobility of beta(m) was shown to be abnormally low due to the presence of Glu-rich sequences. In contrast to mature forms of other known X,K-ATPase beta-subunits, carbohydrate moiety of beta(m) is sensitive to endoglycosidase H and appears to be composed of short high-mannose or hybrid N-glycans. This finding argues in favor of an intracellular location of beta(m) in human skeletal muscle.

Amino Acid Sequence↗
PubMed2000

trans-1-[(2-Phenylcyclopropyl)methyl]-4-arylpiperazines: mixed dopamine D(2)/D(4) receptor antagonists as potential antipsychotic agents.

The dopaminergic receptor profile of a series of trans-1-[(2-phenylcyclopropyl)methyl]-4-arylpiperazines was examined. Aromatic substitution patterns were varied with the goal of identifying a compound having affinities for the D(2) and D(4) receptors in a ratio similar to that observed for the atypical neuroleptic clozapine. The compounds (1S, 2S)-trans-1-[(2-phenylcyclopropyl)methyl]-4-(2, 4-dichlorophenyl)piperazine (5m) and (1S, 2S)-trans-1-[(2-phenylcyclopropyl)methyl]-4-(2, 4-dimethylphenyl)piperazine (5t) were selected for functional antagonists at D(2) and D(4) receptors and had a D(2)/D(4) ratio approximating that of clozapine; they proved inactive in behavioral tests of antipsychotic activity.

Animals↗
PubMed2000

Acute regulation of Na+/H+ exchanger NHE3 by parathyroid hormone via NHE3 phosphorylation and dynamin-dependent endocytosis.

Parathyroid hormone (PTH) is a potent inhibitor of mammalian renal proximal tubule Na(+) transport via its action on the apical membrane Na(+)/H(+) exchanger NHE3. In the opossum kidney cell line, inhibition of NHE3 activity was detected from 5 to 45 min after PTH addition. Increase in NHE3 phosphorylation on multiple serines was evident after 5 min of PTH, but decrease in surface NHE3 antigen was not detectable until after 30 min of PTH. The decrease in surface NHE3 antigen was due to increased NHE3 endocytosis. When endocytic trafficking was arrested with a dominant negative dynamin mutant (K44A), the early inhibition (5 min) of NHE3 activity by PTH was not affected, whereas the late inhibition (30 min) and decreased surface NHE3 antigen induced by PTH were abrogated. We conclude that PTH acutely inhibits NHE3 activity in a biphasic fashion by NHE3 phosphorylation followed by dynamin-dependent endocytosis.

Animals↗
PubMed2000

Implications of EPHB6, EFNB2, and EFNB3 expressions in human neuroblastoma.

Neuroblastoma (NB) is a common pediatric tumor that exhibits a wide range of biological and clinical heterogeneity. EPH (erythropoietin-producing hepatoma amplified sequence) family receptor tyrosine kinases and ligand ephrins play pivotal roles in neural and cardiovascular development. High-level expression of transcripts encoding EPHB6 receptors (EPHB6) and its ligands ephrin-B2 and ephrin-B3 (EFNB2, EFNB3) is associated with low-stage NB (stages 1, 2, and 4S) and high TrkA expression. In this study, we showed that EFNB2 and TrkA expressions were associated with both tumor stage and age, whereas EPHB6 and EFNB3 expressions were solely associated with tumor stage, suggesting that these genes were expressed in distinct subsets of NB. Kaplan-Meier and Cox regression analyses revealed that high-level expression of EPHB6, EFNB2, and EFNB3 predicted favorable NB outcome (P<0.005), and their expression combined with TrkA expression predicted the disease outcome more accurately than each variable alone (P<0.00005). Interestingly, if any one of the four genes (EPHB6, EFNB2, EFNB3, or TrkA) was expressed at high levels in NB, the patient survival was excellent (>90%). To address whether a good disease outcome of NB was a consequence of high-level expression of a "favorable NB gene," we examined the effect of EPHB6 on NB cell lines. Transfection of EPHB6 cDNA into IMR5 and SY5Y expressing little endogenous EPHB6 resulted in inhibition of their clonogenicity in culture. Furthermore, transfection of EPHB6 suppressed the tumorigenicity of SY5Y in a mouse xenograft model, demonstrating that high-level expressions of favorable NB genes, such as EPHB6, can in fact suppress malignant phenotype of unfavorable NB.

Animals↗
PubMed2000

Design, synthesis, and discovery of 3-piperazinyl-3,4-dihydro-2(1H)-quinolinone derivatives: a novel series of mixed dopamine D2/D4 receptor antagonists.

3-Piperazinyl-3,4-dihydro-2(1H)-quinolinone derivatives (delta-lactams) were designed, synthesized, and identified as a new series of mixed dopamine D2/D4 receptor antagonists. To further the structure-activity relationship (SAR) study, 3-piperazinylindolin-2-ones (gamma-lactams) and 3-piperazinyl-3H,4H,5H-benzo[f]azepin-2-ones (epsilon-lactams) were also prepared and examined.

Antipsychotic Agents↗
PubMed2000

Two distinct components of initial glutamate release synchronized with anoxic depolarization in rat global brain ischemia.

Numerous reports have suggested that anoxic depolarization is a critical event in the pathogenesis of cerebral ischemia. Extracellular glutamate concentration ([Glu]e) is closely related to the pathogenesis of ischemia. Therefore, these pathogenic mechanisms merit study, especially the relationship between [Glu]e elevation and the ionic basis of early changes in membrane potential after ischemic insult in vivo. It is often presumed from electrophysiological studies that a causal relationship exists between impaired glutamate uptake and/or progressive glutamate increase and anoxic depolarization, but few in vivo reports have found any sign of a progressive increase of [Glu]e elevation preceding anoxic depolarization. Recently, we reported the application of an oxygen-independent real-time technique for monitoring glutamate levels in the extracellular space during in vivo ischemia, and demonstrated that the massive glutamate release during ischemia is biphasic. In the present study, using this real-time monitoring system, we carried out a more detailed analysis of the initial events in the first phase of glutamate release during ischemia-induced anoxic depolarization. The shape of the rising slope that forms the peak of the first phase suggested two components. The second component was approximately 10 times steeper than the first, with two different components of the rise on the way to the peak of the biphasic [Glu]e elevation. This is the first report to demonstrate these components of the initial glutamate peak, and suggests a progressive second component of the [Glu]e increase preceding Ca2+-dependent release from synaptic vesicles with anoxic depolarization, in vivo.

Animals↗