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Biomedical subjects

H G Zhu

Publications and source records attributed to H G Zhu.

At least 19 recordsLinked to original sources
PubMed2006

Gene expression profile of transgenic mouse kidney reveals pathogenesis of hepatitis B virus associated nephropathy.

Hepatitis B virus (HBV)-associated nephritis has been reported worldwide. Immune complex deposition has been accepted as its pathogenesis, although the association between the presence of local HBV DNA and viral antigen and the development of nephritis remains controversial. To understand better the roles played by HBV protein expression in the kidney, the global gene expression profile was studied in the kidney tissue of a lineage of HBV transgenic mouse (#59). The mice expressed HBsAg in serum, and HBsAg and HBcAg in liver and kidney, but without virus replication. Full-length HBV genome (adr subtype, C genotype) isolated from a chronic HBV carrier was used to establish the transgenic mice #59. Similarly manipulated mice that did not express HBV viral antigens served as controls. Southern blotting, hybridization with HBV probe, and immuno-histochemical staining were used to study HBV gene expression. mRNA extracted from the kidney tissue was analyzed using Affymetrix microarrays. HBsAg and HBcAg were located mainly in the cytoplasm of tubular epithelium. Altogether 520 genes were "up-regulated" more than twofold and 76 genes "down-regulated" more than twofold in the kidney. The complement activation, blood coagulation, and acute-phase response genes were markedly "up-regulated". Compared to the controls, the level of serum C3 protein was decreased in #59 mice, while the level of C3 protein from kidney extract was increased. Results indicate that expression of HBsAg and HBcAg in tubular epithelial cells of the kidney per se can up-regulate complement-mediated inflammatory gene pathways, in addition to immune complex formation.

Animals↗
PubMed2001

[Reconstruction of the common carotid artery with freeze dried arterial allografts in goats].

OBJECTIVE: To observe the patency rate and histopathologic changes at different times after implantation of freeze dried arterial allografts. METHODS: 4 healthy adult goats were used as the experimental models. A segment of the common carotid artery 2 cm in length was surgically removed and bridged with freeze-dried graft of common carotid artery from another goat. The eight necks of 4 animals were divided into A and B group randomly, each containing 4 arteries. In group A, both cut ends of the carotid artery were anastomosed end to end with the arterial allograft. In group B, the proximal end of the carotid artery was anastomosed end to side with the allograft. The patency of the graft was monitored with Laser Doppler Flowmeter within one week and carotid angiography was performed in selected animal. The allografts with anastomoses were harvested at 1 week, 2 weeks, 3 months and 6 months after implantation, respectively. The surgical fresh specimens were prepared and subject to histopathologic evaluation under light microscope, scanning electron microscope and transmission electron microscope. RESULTS: In Group A, 2 grafts were patent at 1 week and 2 weeks, respectively. One graft was not patent at 3 months, one was largely occluded at 6 months, only 1/4 part of the graft was patent. In Group B, 3 grafts were patent at 1 week, 2 weeks, 3 months, respectively. One graft was occluded at 6 months. There was no significant difference in patency rate between the two groups. Histopathologic examinations showed that in freezed dried arterial homograft, the endothelial cells were lost but the matrix was complete. One week after implantation, mononuclear macrophages were infiltrated into the wall in large amount and adventitia of loose connective tissues was formed. After 2 weeks of implantation, intimia was noted, intimal hyperplasia was also noted at the anastomotic sites and migrated toward the central portions of the graft. At 3 months, the homograft displayed a complete endothelial cell coverage with only small areas of fresh fibrin and endothelial disruption. The rejection reaction was diminished prominently. The medial matrix was largely substituted by proliferation of smooth muscle cells, the homograft was near normal in structure. CONCLUSION: Reconstruction of carotid artery defect with freeze dried arterial homografts was feasible. The rejection reaction was not significant. If the endothelial lining does not regenerate within 3 months, long term graft patency is hardly achieved.

English Abstract↗
PubMed2001

[Reconstruction of the common carotid artery with autogenous external jugular vein graft in goats].

OBJECTIVE: To establish a method for reconstruction of carotid artery defect with autogenous graft of external jugular vein, to investigate the patency rate and histopathologic changes at different times after implantation. METHODS: 3 healthy adult goats were used as the experimental models. A segment of 2 cm autogenous external jugular vein was used to bridge a surgical defect of the common carotid artery (2 cm long). The six necks of the three animals were divided into A and B group randomly. In Group A, both cut ends of the artery were anastomosed end to end with the venous graft. In Group B, the proximal end of the artery was anastomosed end to side with the venous graft. The patency rate was recorded at different times. The venous grafts with anastomotic sites were harvested at 2 weeks, 3 months and 6 months after implantation, respectively, for histopathologic examinations. RESULTS: The grafts in Group A were patent at 2 weeks and 3 months, but occluded at 6 months. The grafts in Group B were patent at 2 weeks and 6 months, but not patent at 3 months. Chi-square test demonstrated insignificant difference in patency rate between Group A and Group B. Histopathologic examinations showed intimal hyperplasia and venous arterialization in venous autografts. The venous wall was loose and edematous, intimal and subintimal hyperplasia was prominent at 2 weeks. Proliferation and migration of smooth muscle cell was found at 3 months after implantation. At 6 months, the venous media was predominantly composed of smooth muscle. Intimal hyperplasia was most prominent adjacent to the anastomosis. CONCLUSION: Reconstruction of the common carotid artery with autogenous graft of external jugular vein had a higher patency rate. The main histopathologic changes after implantation is intimal hyperplasia and venous arterialization. Intimal hyperplasia is the result of proliferation and migration of host arterial smooth muscle cell, which passes through the anastomosis to the intima of the vein graft.

English Abstract↗
PubMed2000

Fibronectin and malignant disease-associated DNA-binding protein 2 in hepatocarcinogenesis in rats.

Changes in the plasma concentration of malignant disease-associated DNA-binding protein 2 (MAD2) and in the distribution of fibronectin and MAD2 in liver tissue were studied in Fisher-344 rats with diethylnitrosamine-induced hepatocarcinogenesis. The concentration of plasma MAD2 significantly increased as pre-cancerous lesions developed into hepatocellular carcinoma. We believe that the increased plasma concentration of MAD2 is caused by an increase in the degradation of fibronectin within hepatocellular carcinoma tumors. Therefore MAD2 may be a useful marker for the early detection of hepatocellular carcinoma.

Alkylating Agents↗
PubMed2000

[Concentration of arsenic trioxide in animal tongue tissue by transartery catheterization].

OBJECTIVE: To compare the differences of As(2)O(3) concentration in rabbit tongue tissue between arterial infusion and intravenous injection. METHODS: 4 clean rabbits were divided into the artery group and the vein group at random. The rabbits in both groups received arsenic trioxide of the same concentration and same volume. The tongue tissue from tip to the base of the rabbit were resected at 30,60,120,240 minutes after medication. The concentration in tissue of As(2)O(3) was determined with Gas Chromatography. RESULTS: The concentration of As(2)O(3) in artery group is significantly higher than that in vein group (P<0.01). The average concentration was 7.9 micromol/L in artery group and 1.4 micromol/L in vein group. CONCLUSION: The concentration of As(2)O(3) infused by transartery catheterization was greatly enhanced in local tissue, it reached the concentration that can effectively inhibit the cell proliferation of oral tongue squamous cell carcinoma.

English Abstract↗
PubMed2000

[Application of Continuous Wave Nd:YAG Laser Irradiation in the Management of Cavernous Hemangioma of Deep Oral-Maxillofacial Regions]

OBJECTIVE:Based on our previous clinical report of Nd:YAG laser irradiation as the means for deeling with cavernous hemangioma in deep oral-maxillofacial regions, this article detailed futher clinical application of this laser, trying to set up a non-surgical method for treatment of ang ioma. The relationship of laser dosage and therapeutic effect and possible surrounding tissue thermal damages were investigated.METHODS:Clinical study was carried out on 31 cases of deep hemangiomas involving different areas. Nd:YAG laser irradiation was delivered after surgical elevation of the flaps. All cases surveyed a follow up of 1.5 to 3 years.RESULTS:Posttherapeutic clinical and imaging examinations were taken to compare the findings before and after treatment. There are 29 cases with complete regression (93.55%), 2 cases with partial regression (6.45%). No complication occurred.CONCLUSION:Nd:YAG laser irradiation after flap elevation has been confirmed to be a valuable means to treat deep hemangiomas. It has the advantages of target tissue selection and normal tissue preservation, simplified manipulation and less bleeding, fewer complications and hihger successful rate.

Journal Article↗
PubMed2000

[Anatomical and histologic study of the cervical vessels in goats]

OBJECTIVE:To investigate the normal anatomic relations and histologic features of the cervical arteries and veins of goat, with the aim of providing a basis for resection and reconstruction of the common carotid artery.MATERIALS AND METHODS: Surgical dissection was performed on 15 healthy adult goats under general anaesthesia. The external diameters of the common carotid artery (CCA) and external jugular vein(EJV) were measured at their midpoints. 1 cm of the CCA and EJV was subject to light microscopic examination. Direct carotid angiography was performed on 2 selected goats to observe the course and branches of the carotid artery and normal blood flow mapping of the CCA was recorded using Laser Doppler Flowmeter. RESULTS:The average external diameter of the EJV was 5.4 mm for the left side and 5.3 mm for the right side. The average external diameter of the CCA was 3.8 mm for the left side and 3.6 mm for the right side. Histologic examinations found that the media of the carotid artery had 10-15 layers of smooth muscles. The EJV had valvulae, its wall was thin, only 1-2 layers of smooth muscle were contained in its medium. CONCLUSION:The CCA and EJV of the goat had a longer course in the neck, and a larger diameter (3-5 mm). Their histologic structures were similar to that of the human being, which makes it advantageous to be more often used as an animal model in experimental surgery.

Journal Article↗
PubMed1999

Genotoxicity of microcystic cyanobacteria extract of a water source in China.

The water pollution of toxic cyanobacteria (blue-green algae) is a worldwide problem and worsens with industrialization. Microcystins are potent cyclic heptapeptidic hepatotoxins produced mainly by Microcystis aeruginosa, and their hepatotoxicity has been well-documented. In contrast, information on the genotoxic effects of microcystins is relatively scarce. In our present study, the genotoxicity of microcystic cyanobacteria extract (MCE) of a water source in China was studied using Salmonella typhimurium assay (Ames test), comet assay (Single cell gel electrophoresis) and mouse micronucleus test. Results from Ames test indicated that MCE had strong mutagenicity regardless of the presence of S9. Moreover, MCE was able to induce DNA damage in primary cultured rat hepatocytes examined by comet assay. In addition, MCE also enhanced bone marrow micronucleated polychromatic erythrocytes in mice. The analysis of HPLC showed that the main component of MCE was microcystin-LR. The understanding of the potent genotoxicity of MCE will help to establish the possible link between water cyanobacteria contamination and high risk of primary liver cancer found in some endemic areas.

Animals↗
PubMed1999

[Rabbit facial nerve damager after Nd: YAG laser irradiation: an experimental study]

OBJECTIVE:To investigate the change effects of rabbit facial nerve after Nd:YAG laser irradiation.METHODS: According to therapeutic laser energy density,the facial nerves of 28 rabbits were irradiated by Nd:YAG laser with 5 different laser dosages.RESULTS: The facial nerves were functionally intact with mild degeneration histologically at three weeks postoperatively,when the energy density of Nd: YAG laserlaser lower than 70J/cm(2).In the group with energy density of 140J/cm(2),facial nerve density functionally impaired with moderate degeneration which rehabilitated within six weeks. While the laser power increaseed to more than 240J/cm(2),irreversible nerve damages happened.CONCLUSION: laser thermal effect is the main cause of nerve damage,there is a positive correlation between laser dosage and nerve impairment.

Journal Article↗
PubMed1999

[lnhibition of arsenic trioxide on human tongue cancer cell line Tca8113 cells in Scid mice in vivo]

OBJECTIVE:To explore the antitumor effect of As(2)O(3) in Scid mice.METHODS:Human tongue cancer cell line Tca8113 cells were transp lanted to the subcutaneous tissues of Scid mice to produce tumors.The tumor inhibition rate (TIR) of As(2)O(3) was observed in Scid mice. RESULTS:The TIR of As(2)O(3) was 49.16%,Cytomorphologic study showed that arsenic trioxide induced apoptosis of Tca8113 cells.CONCLUSION: As(2)O(3) may have a good treating effect on oral squamous cell carcinoma.

Journal Article↗
PubMed1998

Studies on oxidative damage induced by cyanobacteria extract in primary cultured rat hepatocytes.

Contamination of water by cyanobacteria (blue-green algae) is a serious health problem around the world, largely due to the toxic effects of microcystins, a group of potent hepatotoxins. However, the mechanisms responsible for the cytotoxicity of microcystins have not been fully elucidated. In the present study, oxidative damage caused by lyophilized freshwater cyanobacteria extract was evaluated on primary cultured rat hepatocytes. A time- and dose-dependent increase of lactate dehydrogenase (LDH) leakage was observed in hepatocytes treated with cyanobacteria extract. Lipid peroxidation, a main manifestation of oxidative damage, was also studied and a time- and dose-dependent increase in malondiadehyde was observed. In addition, by using a fluorescent probe, 2',7'-dichlorofluorescein diacetate, it was found that cyanobacteria extract was able to enhance intracellular production of reactive oxygen species (ROS) in a dose- and time-dependent manner. Moreover, desferrioxamine, a specific iron chelator, could significantly decrease LDH leakage and ROS production caused by cyanobacteria extract treatment. These findings thus provide experimental evidence that oxidative damage is involved in cyanobacteria extract-induced hepatotoxicity. The understanding of this mechanism is believed to be beneficial to the prevention and control of the toxicity of microcystin and cyanobacteria contamination.

Animals↗
PubMed1998

Microcystic cyanobacteria causes mitochondrial membrane potential alteration and reactive oxygen species formation in primary cultured rat hepatocytes.

Cyanobacteria contamination of water has become a growing public health problem worldwide. Microcystis aeruginosa is one of the most common toxic cyanobacteria. It is capable of producing microcystins, a group of cyclic heptapeptide compounds with potent hepatotoxicity and tumor promotion activity. The present study investigated the effect of microcystic cyanobacteria on primary cultured rat hepatocytes by examining mitochondrial membrane potential (MMP) changes and intracellular reactive oxygen species (ROS) formation in cells treated with lyophilized freshwater microcystic cyanobacteria extract (MCE). Rhodamine 123 (Rh-123) was used as a fluorescent probe for changes in mitochondrial fluorescence intensity. The mitochondrial Rh-123 fluorescence intensity in MCE-treated hepatocytes, examined using a laser confocal microscope, responded in a dose- and time-dependent manner. The results thus indicate that the alteration of MMP might be an important event in the hepatotoxicity caused by cyanobacteria. Moreover, the parallel increase of ROS formation detected using another fluorescent probe, 2',7'-dichlorofluorescin diacetate also suggests the involvement of oxidative stress in the hepatotoxicity caused by cyanobacteria. The fact that MMP changes precede other cytotoxic parameters such as nuclear staining by propidium iodide and cell morphological changes suggests that mitochondrial damage is closely associated with MCE-induced cell injury in cultured rat hepatocytes.

Animals↗
PubMed1996

[Surgical approach plus Nd:YAG laser irradiation for the management of hemangioma in deep maxillofacial region]

This article introduces a new method for the management of cavernous hemangioma in deep maxillofacial region.Common surgical approach was carried out to expose the mass of hemangioma,then Nd:YAG laser was irradiated it without tumor removal.Immediatelly shrinking of hemangioma can be seen in all these seven cases.The therapeutic effect was satisfied in 3-12 months follow up.With the basic research of the rabbit facial nerve's Nd:YAG laser injured detecting experiment.We discussed its indication,advantage and interaction between laser and peripheral tissue.Our result shown that this new way is a good method for hemangioma in deep maxillofacial region as its advantages of skin preventing and peripheral normal tissue preserving

Journal Article↗
PubMed1996

[Experiment study on biological and immunological characteristics of modified DNL of oral squamous cell carcinoma with TNF-alpha gene]

Growing characteristic of gene-transduced and nontransduced DNL in medium of containing rIL-2 was compared,and growing characteristic of gene-transduced DNL in medium of non containing rIL-2 was analyzed.DNA index (DI),cell cycle and immunologic phenotypes of gene-transduced and nontransduced DNL were analyzed with FACS.The results revealed interfered with growth,DL,cell cycle and immunologic phenotypes of DNL,and gene-transduced DNL couldn't growing infinitely.

Journal Article↗