Biomedical subjects

H Qiao

Publications and source records attributed to H Qiao.

At least 19 recordsLinked to original sources

PubMed2006

Taurine protects against ischemia-reperfusion injury in rabbit livers.

Ischemia-reperfusion injury is of major clinical relevance during liver transplantation. In the present study, the therapeutic efficacy of taurine to protect against ischemia-reperfusion injury was investigated in rabbit livers. We demonstrated that intravenous injection of taurine attenuated liver dysfunction as evidenced by reductions in serum alanine aminotransferase, aspartate transaminase, and alkaline phosphatase. The recovery of morphological and ultrastructural changes in the liver was also promoted by taurine. The mechanism of the protective effect of taurine seems at least to rely on antioxidation, since the lipoperoxides contents in liver tissues were significantly reduced among taurine-treated rabbits. These results suggest that taurine is a potent useful reagent to protect the rabbit liver from ischemia-reperfusion injury.

Animals↗

PubMed2006

Analysis of corneal inflammation induced by cauterisation in CCR2 and MCP-1 knockout mice.

AIM: To elucidate the role of CCR2/MCP-1 in corneal inflammation. METHODS: A cauterisation induced corneal inflammation model was used. The corneas were cauterised with silver nitrate in CCR2 knockout (KO) mice, MCP-1 KO mice, and control mice. Clinical signs such as corneal oedema and opacity were examined 96 hours after cauterisation and the phenotypes of the cells infiltrating the cornea were analysed by flow cytometry. Corneal inflammation in neutrophil depleted mice was also analysed. RESULTS: After cauterisation both CCR2 KO and MCP-1 KO mice showed the same levels of corneal oedema and opacity as control mice. Flow cytometry revealed that in control mice most of the infiltrating cells were neutrophils and macrophages, whereas in both CCR2 KO mice and MCP-1 KO mice, the number of macrophages infiltrating the cornea were markedly reduced. However, prominent infiltrates of neutrophils were still observed in the cornea in CCR2 KO mice and MCP-1 KO mice. The depletion of neutrophils significantly reduced the oedema and opacity induced in the cornea by cauterisation. CONCLUSION: The CCR2 and MCP-1 molecules are not essential for cauterisation induced corneal inflammation. Neutrophils, rather than migrated macrophages, are the final effector cells involved in inducing inflammation in this model.

Animals↗

PubMed2005

TSPY is a cancer testis antigen expressed in human hepatocellular carcinoma.

In search for genes associated with hepatocellular carcinoma (HCC) by cDNA microarray, we found that the transcription of TSPY, 'testis-specific protein Y-encoded', was upregulated in HCC. Investigation of a broad spectrum of normal and malignant tissues by RT-PCR revealed the TSPY transcript selectively expressed in normal testis, different histological types of human neoplastic tissues, and tumour cell lines. The expression of TSPY in cancer cells was further confirmed by in situ hybridisation. Indirect immunofluorescence microscopy analysis showed that TSPY was localised mainly in the cytoplasm of transiently transfected cells. Testis-specific protein Y-encoded was detected in 50% (16 of 32) of well- and moderately differentiated HCC patients, in 16% (four of 25) of poorly differentiated HCC patients, and in 5% (one of 19) of renal cell cancer patients. A serological survey revealed that 6.6% (seven of 106) HCC patients had anti-TSPY antibody response, demonstrating the immunogenicity of TSPY in humans. In conclusion, these data suggest that TSPY is a novel cancer/testis (CT) antigen and may be a potential candidate in vaccine strategy for immunotherapy in HCC patients.

Antigens, Neoplasm↗

PubMed2005

Effects of fluvoxamine on levels of dopamine, serotonin, and their metabolites in the hippocampus elicited by isolation housing and novelty stress in adult rats.

The authors investigated the effects of fluvoxamine on neurochemical changes in the hippocampus elicited by isolation housing and novelty stress. Male F344 rats (11 w) were housed one per cage for four weeks. On each day of the last week (7 days) they were s.c. injected with fluvoxamine (20 mg/kg), and then subjected to novelty stress. Isolation housing significantly increased dihydroxyphenylacetic acid (DOPAC) and 5-hydroxyindoleacetic acid (5-HIAA) levels, whereas fluvoxamine significantly decreased them. Isolation housing significantly increased the DOPAC/DA ratio. Fluvoxamine significantly decreased the DA level, and partially restored the DOPAC and 5-HIAA levels increased by isolation housing.

3,4-Dihydroxyphenylacetic Acid↗

PubMed2005

The characterisation of hyalocytes: the origin, phenotype, and turnover.

AIM: To determine the characterisation of hyalocytes: the origin, phenotype, and turnover in the rodent. METHODS: To characterise the ultrastructure and distribution of hyalocytes, transmission and scanning electron microscopy was performed in rat eyes. Immunophenotypical analysis was performed by either anti-ED1 or ED2 antibodies. To examine the origin of the hyalocytes, the chimeric mice were created and were used to transplant the bone marrow (BM) cells from enhanced green fluorescent protein (EGFP) transgenic mice. The turnover of hyalocytes was examined at 0, 4, 6, 7, and 12 months after BM transplantation. RESULTS: Hyalocytes were distributed especially in the vitreous cortex and had an irregular shape with a spherical granule. Immunophenotypical studies demonstrated that most of the hyalocytes in rat eyes expressed ED2 but not ED1. In the chimeric mice, the hyalocytes were GFP negative right after BM transplantation. Interestingly, more than 60% of hyalocytes were replaced within 4 months and approximately 90% within 7 months after BM transplantation. CONCLUSIONS: The rodent hyalocytes were shown to express tissue macrophage marker, were derived from BM, and totally replaced within 7 months. These data provide the characterisation of hyalocytes in physiological conditions, especially their origin, distribution, and turnover, and may contribute to the better understanding of the pathogenesis of vitreoretinal disease.

Animals↗

PubMed2004

Volumetric estimation of functional brain regions in small children using spatially filtered magnetoencephalography: differentiating thumb from middle finger.

It is difficult to localize the somatosensory cortex in children under 6 years using magnetoencephalography (MEG) with conventional median nerve stimulation. One main reason is that MEG data recorded from small children have poor signal-to-noise ratio due to their small heads and short hands. To find a better approach, this study investigated neuromagnetic activities following finger stimulation using spatially filtered MEG. Four healthy children have been studied with a whole cortex MEG system. Electric stimulation was applied to the thumb and the middle fingers with two Digital Rings. Two trials were recorded for each hand. Focal increases of spectral power were localized using spectrogram and synthetic aperture magnetometry (SAM). A clear response at a latency of 21 ms was identified in 3 children (3/4). Dipole modeling localized the somatosensory cortex in 2 children (2/4). SAM successfully localized the somatosensory cortex in 4 children (4/4). Interestingly, the functional region estimated for the thumb was significantly larger than that of the middle finger (p < 0.01). However, it is possible that this effect is due to a larger source amplitude rather than larger source volume. Our results demonstrated that the developed approach could map the somatosensory cortex in children ranging in age from 3 to 6. To our knowledge, this is the first report using non-invasive methods to provide quantitative data indicating that the functional area of the thumb is larger than that of the middle finger in small children.

Child↗

PubMed2004

Automatic localization of epileptic zones using magnetoencephalography.

Conventional visual identification of epileptic spike is a challenging problem in the clinical application of magnetoencephalography (MEG). More importantly, the conventional method has problems of detecting other abnormalities such as high frequency oscillation in the human epileptic brain. The objective of this study was to develop a new approach using magnetic spectral analysis and spatial filtering. Twelve patients with seizure have been studied with a whole cortex MEG system. Fifteen epochs were recorded for each patient; each epoch was 120 seconds. Neuromagnetic spectrum was analyzed using a new method called accumulated spectrogram. Focal increases of spectral power were localized using synthetic aperture magnetometry (SAM). The MEG results were then compared with clinical findings. Focal increases of spectral power have been identified in all patients (12/12, 100%). The locations of the focal increases of spectral power were in agreement with dipole locations of spikes in 9 patients (9/12, 75%). A comparison between MEG results and clinical findings indicated that SAM revealed focal epileptic activities in two patients when dipole fitting failed. The results suggest that epileptic regions could be quantitatively identified and accurately localized using accumulated spectrogram and SAM. In comparison to visual identification of spike, the new approach is objective and sensitive, and provides the possibility of analyzing much wider frequency bands.

Adolescent↗

PubMed2004

Fluvoxamine, a selective serotonin reuptake inhibitor, suppresses tetrahydrobiopterin levels and dopamine as well as serotonin turnover in the mesoprefrontal system of mice.

RATIONALE: Tetrahydrobiopterin (BH4) is a coenzyme of tyrosine hydroxylase (TH) and tryptophan hydroxylase (TPH), rate-limiting enzymes of monoamine biosynthesis. According to the monoamine hypothesis of depression, antidepressants will restore the function of the brain monoaminergic system, and BH4 concentration. OBJECTIVE: To investigate the effects of fluvoxamine on BH4 levels and dopamine (DA) and serotonin (5-HT) turnover in the mesoprefrontal system, incorporating two risk factors of depression, social isolation and acute environmental change. METHODS: Male ddY mice (6W) were divided into two housing groups, i.e. group-housing (eight animals per cage; 35 days), and isolation-housing (one per cage; 35 days), SC injected with fluvoxamine (20 or 40 mg/kg; days 29-35), and exposed to 20-min novelty stress (day 35). The levels of BH4, DA, homovanilic acid (HVA), 5-HT, and 5-hydroxyindoleacetic acid (5-HIAA) were measured in the prefrontal cortex and midbrain. RESULTS: Under the group-housing condition, novelty stress significantly increased BH4 levels in both regions, and the HVA/DA ratio in the midbrain, whereas it did not change any parameters in either region under the isolation-housing condition. In the prefrontal cortex, fluvoxamine significantly decreased the 5-HIAA/5-HT ratio under the group-housing condition, and BH4 levels and the HVA/DA ratio under the isolation-housing condition. In the midbrain, fluvoxamine significantly decreased all parameters, except for an increasing in the 5-HIAA/5-HT ratio under the isolation-housing condition. CONCLUSION: Isolation-housing suppressed the increase of BH4 levels and DA turnover elicited by novelty stress. Fluvoxamine suppressed BH4 levels, and DA and 5-HT turnover. Fluvoxamine may have altered DA turnover by suppressing BH4 levels.

Animals↗

PubMed2004

Fluvoxamine, a selective serotonin reuptake inhibitor, suppresses tetrahydrobiopterin in the mouse hippocampus.

In the present study, we investigated the effects of fluvoxamine, a selective serotonin reuptake inhibitor, on brain tetrahydrobiopterin (BH4) levels. We directly measured levels of BH4 by Tani and Ohno's direct method as well as the serotonin (5-HT) turnover ratio, i.e. 5-hydroxyindoleacetic acid (5-HIAA)/5-HT, after sub-acute s.c. injection of fluvoxamine in the hippocampus of mice. Our animal model incorporated two risk factors of depression, social isolation and acute environmental change. Male ddY mice (6W) were housed in isolation (1 per cage; 35 days), injected with fluvoxamine (20 or 40 mg/kg; days 29-35), and exposed to novelty stress (20 min; day 35). In the stress session, behavioral parameters, i.e. total distance and rearing behavior, were measured. Isolation housing increased both behaviors. Fluvoxamine attenuated rearing behavior, but did not influence total distance. Isolation housing increased BH4 levels. Novelty stress increased BH4 levels in group housing, although it did not change them in isolation housing. Fluvoxamine suppressed BH4 levels. In isolation housing, fluvoxamine increased 5-HT turnover ratios, while it decreased them in group housing. In conclusion, fluvoxamine, housing condition, and novelty stress regulated BH4 levels. Fluvoxamine may have changed behavior and 5-HT turnover by suppressing BH4 levels as well as by inhibiting 5-HT reuptake.

Animals↗

PubMed2004

Gene transfer of interleukin-4 delays acute rejection of splenic allografts in rats.

Spleen transplantation is the treatment of choice for some diseases, such as hemophilia A. However, the risk and intensity of rejection after spleen transplantation is greater and more difficult to control than other types of transplant. In the present study, we demonstrated that perfusion of IL-4 expression plasmids into donor spleens pretransplantation led to overexpression of IL-4 and downregulation of IFN-gamma in situ, associated with delayed acute rejection of the allograft. Gene transfer of IL-4 may represent a potential therapeutic approach to induce tolerance to splenic allografts.

Animals↗

PubMed2004

Administration of tolerogenic dendritic cells induced by interleukin-10 prolongs rat splenic allograft survival.

The risk and intensity in splenic graft rejection are greater than in other types of transplants, because the spleen is the largest peripheral lymphoid organ and the immunosuppressive drugs administered can cause splenic dysfunction. In this study, we demonstrate that intravenous injection of interleukin-10-treated donor-type dendritic cells into recipient rats prolongs the survival of splenic allografts. Although the mechanisms are not clear, the induction of tolerance to grafted spleens seems to rely mainly on blockage of expression of the costimulatory molecule CD86, by interleukin-10, leading to enhanced apoptosis of allospecific T cells by immature and tolerogenic dendritic cells. Administration of tolerogenic cells induced by interleukin-10 may thus represent a useful approach for protection of splenic allografts. Further study is required to investigate the operative pathways and to optimize the strategy targeting dendritic cells to induce tolerance in splenic allografts.

Animals↗

PubMed2004

The relative contributions of each subset of ocular infiltrated cells in experimental choroidal neovascularisation.

AIM: Choroidal neovascularisation (CNV) is a major cause of blindness in adults. The aim of this study was to investigate the role of infiltrating cells in the development of experimental CNV. METHODS: CNV was induced in C57BL/6 (B6) mice by laser photocoagulation (PC). After PC, the numbers of each subset of infiltrated cells were analysed by flow cytometry at multiple time points. Each subset (except for macrophages) was depleted by the specific antibodies in vivo. Thereafter, the area of CNV was compared between the control B6 mice and the specific antibody treated mice 7 days after PC. The CNV formation in neutrophil depleted CC chemokine receptor-2 (CCR2) knockout mice was also examined to minimise the effects of macrophages. RESULTS: In the early phase of CNV formation, a large number of neutrophils and macrophages infiltrated to the eyes. Natural killer (NK) cells and T lymphocytes were barely detected while no B lymphocytes were detected. The CNV areas did not significantly change compared between the control B6 mice and the specific antibody treated mice. However, the neutrophil depleted CCR2KO mice resulted in a reduction of CNV. CONCLUSION: Although lymphocytes and NK cells had little effect on CNV formation, neutrophils partially contributed to CNV in the absence of macrophages.

Animals↗

PubMed2001

Clozapine, but not haloperidol, reverses social behavior deficit in mice during withdrawal from chronic phencyclidine treatment.

Phencyclidine (PCP) reduced social behavior (SB) in a dose- and time-dependent fashion. However, no such SB deficit was observed on repeated treatment with methamphetamine for 14 days. The SB deficit produced by treatment with PCP (10 mg/kg/day) for 14 days, which persisted for 28 days after withdrawal, was attenuated by clozapine (10 mg/kg/day) given for 7 days, whereas haloperidol for 7 days had no effect. Clozapine, but not haloperidol, alone at the same treatment dose increased SB in saline-treated mice. These results suggest that the proposed PCP model in mice will provide a tool to test beneficial effects of atypical antipsychotics on social dysfunction in schizophrenia, and contribute to our understanding of the mechanisms by which clozapine improves SB deficit.

Animals↗

PubMed2001

Modified cold storage of rat livers with self-made HYD solution.

OBJECTIVE: To investigate the cold preservation effect on rat livers of a modified storage method with self-made HYD solution. METHODS: The vascular bed of rat livers was expanded with an additional 20 to 40 ml self-made HYD solution/100 g liver. After resection of the liver, the extra HYD solution (expressed as % liver weight) was entrapped via portal infusion by tying off the supra- and infra-hepatic inferior vena cava. Forty rats were randomly divided into four groups including control group with conventional storage method, and 20%, 30% and 40% groups according to the amount of extra HYD solution. We compared the preservation effect of the modified storage method with that of the conventional storage method using an isolated perfused rat liver model. RESULTS: Bile production and all the indices of hepatic microcirculation including portal perfusion pressure, endothelin-1 in the effluent, trypan blue distribution time and histology were significantly superior in the modified method groups compared to those in the control group (P < 0.05). The contents of dihydroxybenzoic acid (DHBA) in the modified method groups were significantly lower than those in the control group (P < 0.05). Liver enzymes activities in the 30% group were markedly lower than those in the control group (P < 0.05). The preservation effect on rat liver in the 30% group was the best among the modified method groups. CONCLUSION: The modified cold storage method is effective and may have potential for clinical application in liver preservation.

Alanine Transaminase↗

PubMed2000

Cooperative effect of hepatocyte growth factor and fibronectin in anchorage-independent survival of mammary carcinoma cells: requirement for phosphatidylinositol 3-kinase activity.

Anchorage-independent survival and growth are critical characteristics of malignant cells. We showed previously that the addition of exogenous hepatocyte growth factor (HGF) and the presence of fibronectin fibrils stimulate anchorage-independent colony growth of a murine mammary carcinoma, SP1, which expresses both HGF and HGF receptor (Met; R. Saulnier et al., Exp. Cell Res., 222: 360-369, 1996). We now show that tyrosine phosphorylation of Met in carcinoma cells is augmented by cell adhesion and spreading on fibronectin substratum. In contrast, detached serum-starved cells exhibit reduced tyrosine phosphorylation of Met and undergo apoptotic cell death within 18-24 h. Under these conditions, the addition of HGF stimulates tyrosine phosphorylation of Met and restores survival of carcinoma cells. Soluble fibronectin also stimulates cell survival and shows a cooperative survival response with HGF but does not affect tyrosine phosphorylation of Met; these results indicate that fibronectin acts via a pathway independent of Met in detached cells. We demonstrated previously that inhibition of phosphatidylinositol (PI) 3-kinase activity blocks HGF-induced DNA synthesis of carcinoma cells (N. Rahimi et al., J. Biol. Chem., 271: 24850-24855, 1996). We now show in detached cells a cooperative effect of HGF and FN in the activation of PI 3-kinase and on the phosphorylation of PKB/Akt at serine 473. PI 3-kinase activity is also required for the HGF- and fibronectin-induced survival responses, as well as anchorage-independent colony growth. However, c-Src kinase or MEK1/2 activities are not required for the cell survival effect. Together, these results demonstrate that the PI 3-kinase/Akt pathway is a key effector of the HGF- and fibronectin-induced survival response of breast carcinoma cells under detached conditions and corroborate an interaction between integrin and HGF/ Met signalling pathways in the development of invasive breast cancer.

Animals↗

PubMed2000

[Inhibition of monocytes adhesion to the intima of arterial wall by local expression of antisense monocyte chemotactic protein-1].

OBJECTIVE: To study the mechanism of monocyte recruitment in atherogenesis and to clarify the effect of monocyte chemotactic protein-1 (MCP-1) in this process. METHODS: Femoral arteries isolated from the rabbits which had been fed with a high cholesterol diet and locally perfused with MM-LDL within the artery beforehand, were used as the models. Antisense MCP-1cDNA was transferred into the arterial wall by injecting recombinant LNCX-anti-MCP-1/liposomal complex in the femoral sheath and the periarterial tissue. RESULTS: Expression of antisense MCP-1 mediated by recombinant LNCX plasmid/lipsomal complex gene transfer enabled to inhibit MCP-1 gene expression and adhesion of monocyte to the intima. CONCLUSION: MCP-1 plays an important role on the recruitment of monocytes in the arterial wall, which provides a potential clue in developing a gene therapy project for the prevention and treatment of atherogenesis.

Animals↗

PubMed2000

Study on modified cold storage method of rat livers with self-made hyd solution.

OBJECTIVE: To investigate the cold preservation effect of rat livers by modified storage method with self-made HYD solution. METHODS: The modified method was that the vascular bed of rat livers was expanded with an additional 20 to 40ml self-made HYD solution/100g liver. After removing the liver, the extra HYD solution expressed as % liver weight was entrapped via portal infusion by tying off the supra-and infra hepatic inferior vena cava. According to the amount of extra HYD solution, 40 rats were randomly divided into four groups including: control group with conventional storage method, 20% group, 30% group and 40% group. The preservation effect of modified storage method with that of conventional storage method by using isolated perfused rat liver model was compared. RESULTS: Bile production and all the indices of hepatic microcirculation including portal perfusion pressure, endothelin-1 in the effluent, trypan blue distribution time and histology in modified method groups were significantly superior to those in control group (P < 0.05). The liver enzymes in 30% group were markedly lower than those in control group (P < 0.05). The preservation effect of rat liver in 30% group was the best among the modified method groups. CONCLUSION: The modified cold stage method is effective and may have potential for clinical application for liver preservation.

Alanine Transaminase↗

PubMed2000

Difference of rejection in single versus combined pancreas and kidney transplantation in rats.

OBJECTIVE: To investigate the difference of rejection in single versus combined pancreas and kidney transplantation in rats. METHODS: Allograft models including simultaneous pancreas and kidney (SPK) transplant and pancreas or kidney transplant alone were established in SD-Wistar rats, rejections of pancreas and kidney in different models were compared morphologically and functionally. RESULTS: Mean survival time (MST) of pancreas was significantly prolonged in SPK than in pancreas transplant alone (PTA) (11.5 days vs. 9.2 days, P < 0.05). Incidence of interstitial pancreatic rejection at gade II and grade III was much obvious in PTA than in SPK (42.9% vs. 12.5% at grade II and 28.6% vs 6.3% at grade II , P < 0.05). No significant difference was found in MST between SPK and kidney transplant alone( KTA). Administration of cyclosporine A prolonged the MST of pancreas and kidney, without altering the tendency stated above. CONCLUSIONS: In SPK, the function of pancreas is protected by kidney hence the severity of rejection is reduced, whereas the function of kidney is not protected by pancreas. It suggests that different organs differ in immunoallergization and immunoregulation, and immune response tend to attack organs with greater immunoactivity, those organs with minor one could be protected. Cyclosporine A is effective on prolonging the MST of pancreas and kidney.

Animals↗