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Biomedical subjects

Hua Gao

Publications and source records attributed to Hua Gao.

At least 37 records · Page 2Linked to original sources
PubMed2005

Inhibitory effect of picroside II on hepatocyte apoptosis.

AIM: To investigate the influence of picroside II on hepatocyte apoptosis and its mechanism. METHODS: Morphological changes and quantification of apoptotic cells were determined under transmission electron microscopy and flow cytometry respectively. DNA fragmentation was visualized by agarose gel electrophoresis. Semi-quantitative reverse transcription-PCR (RT-PCR) was used to analyze the expression of bcl-2 and bax genes. The content of manganese-superoxide dismutase (SOD) in liver mitochondria was detected by the Marland method. The content of malonic aldehyde (MDA) and the protein level in liver tissue were determined by thiobarbituric acid colorimetry and Lowry method. RESULTS: Picroside II decreased the levels of alanine aminotransferase and aspartate aminotransferase in the serum resulting from acute-liver injured mice induced with D-GalN and LPS; it also reduced the content of MDA, and thus, enhanced the activity of SOD. Picroside II 10 mg/kg was found to protect hepatocytes against apoptosis in a dose-dependent manner; it up-regulated the expression of bcl-2 genes, thus increased the bcl-2/bax ratio. CONCLUSION: Picroside II can protect hepatocytes against injury and prevent hepatocytes from apoptosis. It might by upregulating the bcl-2 gene expression and antioxidation.

Animals↗
PubMed2005

[Combined penetrating keratoplasty with keratolimbal allograft transplantation in the treatment of severe corneal burns].

OBJECTIVE: To study the clinical results of combined penetrating keratoplasty with keratolimbal allograft transplantation in the treatment of severe corneal burns. METHODS: The present study consisted of 35 eyes (34 patients) with full thickness corneal opacities and extensive corneal conjunctivalization after severe corneal burns. The duration between the injury and the time of presentation ranged from four months to 23 years. Group A: Combined penetrating keratoplasty (PK) with annular keratolimbal allograft transplantation (KLAT) was performed in 19 eyes (18 patients). Group B: Total PK with a scleral rim was performed in 16 eyes (16 patients). Post-operative visual acuity, intraocular pressure, graft rejection and complications were monitored. The average follow up time was 24 (range from 15 to 28) months. RESULTS: (1) Vision: The number of eyes that obtained best corrected visual acuity > 0.05 was 18 eyes (95%) in group A and 14 eyes (84%) in group B at 6 months postoperatively (P = 0.582); 16 eyes (88%) in group A and 6 eyes (38%) in group B at 12 months (P = 0.006); 12 eyes (63%) in group A and 3 (7%) in group B at 24 months (P = 0.016). (2) Graft rejection: Nine allografts (47%) in group A and 8 grafts (50%) in group B developed limbal stem cell rejection (P = 1.000); 6 allografts (32%) in group A and 11 allografts (69%) in group B developed endothelium rejection (P = 0.044). The difference of endothelium rejection rate between group A and B was not significant at different times postoperatively. (3)COMPLICATIONS: Corneal epithelium defect occurred in 2 eyes (11%) in group A and 7 (44%) eyes in group B (P = 0.049); hyphema occurred in 2 eyes (11%) in group A and 8 eyes (50%) in group B (P = 0.022); hypotony occurred in 1 eye (5%) in group A and 6 eyes (38%) in group B (P = 0.032). CONCLUSIONS: PK combined with KLAT is an effective treatment for severe corneal burns at a late stage irrespective of the etiology. This procedure can restore visual function in severely damaged eyes. Patients treated with PK combined with KLAT show less complication and better prognosis as compared with patients treated with total PK with a scleral rim.

Adolescent↗
PubMed2005

[Evaluation of antifungal chemotherapeutic effects on fungal keratitis by confocal microscopy].

OBJECTIVE: To evaluate the validity of confocal microscopy in estimating curative effect and in directing the treatment for fungal keratitis in the process of antifungal chemotherapy. METHODS: Fifty-eight patients, who were confirmed fungal infection by confocal microscopy, were selected from 328 patients with fungal keratitis. All patients received routine topical and/or oral antifungal medication, and were examined by confocal microscopy once a week and one week after discontinuation of the treatment. The density of hyphae in the corneal lesion, the configuration of inflammatory cells and keratocyte were recorded. Antifungal chemotherapy was adjusted according to examination results and medicines were changed accordingly. If no hyphae were detected by confocal microscopy, antifungal medication was maintained for one week and then discontinued. All patients were followed up for two months to ensure no relapse of fungal infection. RESULTS: Fifty three patients were cured. The area of corneal lesions began to reduce 7 days after the beginning of antifungal chemotherapy. Confocal microscopy examination revealed that the hypha positive sites and the density of hypha were reduced gradually; inflammatory cells also decreased, the configuration of corneal lesion was transformed from asymmetry to symmetry; and normal keratocytes could be detected gradually. After 14 days of treatment, ulcers healed up in 37 cases and no hyphae and inflammatory cells were found in 23 cases. After 28 days of treatment, all corneal ulcers healed up; hyphae and inflammatory cells were completely disappeared in 31 patients, but a few hyphae still could be found in 22 patients. Antifungal chemotherapy was tapered gradually if no hyphae and inflammatory cells were detected by confocal microscopy. There was no relapse of fungus infection during 2-month follow-up. Infection deteriorated in the other five patients within 7 days, which showed increased density of hypha and inflammatory cells under confocal microscopy examination. All of them were treated with a penetrating keratoplasty to save the eyeball. CONCLUSIONS: Confocal microscopy is an ideal method for the evaluation of curative effects of fungal keratitis in the process of antifungal chemotherapy. This is also a valuable objective tool in directing antifungal medication.

Adolescent↗
PubMed2005

[Ocular surface reconstruction for severe symblepharon resulting from eye burns].

OBJECTIVE: To evaluate the efficacy of lamellar keratoplasty (LKP) using fresh graft with limbus, combined with conjunctival limbal autograft transplantation (CLAT) and amniotic membrane transplantation (AMT), in treating severe symblepharon resulting from eye burns. METHODS: Patients with severe symblepharon visited our hospital between February 1998 and February 2003 were divided into 4 degrees based on impairment of visual function. Pseudopterygium was partially dissected after separation of conjunctival adhesion, the corneal lesion was covered with partial (17 eyes) or total (9 eyes) lamellar corneal graft. Autologous limbal graft was placed onto the most seriously damaged limbus. Then the preserved pseudopterygium was receded with AMT to reconstruct fornix. All cases were followed up for 8 months to 3 years. Eye movement, diplopia, development of corneal grafts, preserved pseudopterygium and transplanted amniotic membrane were observed. RESULTS: 25 eyes, except that 1 eye because of irreformable lagophthalmos, got considerable improvement. Conjunctival adhesion was completely relieved and diplopia disappeared in 17 eyes. Adhesion recurred in the area covered only with amniotic membrane in 8 eyes, and 5 of them were completely relieved after one or two adhesion excisions combined with autologous conjunctival transplantation. Mild adhesion still remained in 3 eyes. Amniotic membrane began autolyzing at 1 week and completely disappeared 3 months after operation. Pseudopterygium began thinning at 1 to 3 months. Immune rejection occurred in 6 eyes, and 2 of them had second LKP. CONCLUSIONS: LKP using fresh graft with limbus, combined with CLAT and AMT, is an ideal treatment for severe symblepharon resulting from eye burns. Pseudopterygium can partly substitute conjunctiva to reconstruct fornix. Amniotic membrane facilitates ocular surface reconstruction by temporary protection of lesions.

Adolescent↗
PubMed2004

Early B cell factor cooperates with Runx1 and mediates epigenetic changes associated with mb-1 transcription.

Cd79a (called mb-1 here) encodes the Ig-alpha signaling component of the B cell receptor. The early B cell-specific mb-1 promoter was hypermethylated at CpG dinucleotides in hematopoietic stem cells but became progressively unmethylated as B cell development proceeded. The transcription factor Pax5 activated endogenous mb-1 transcription in a plasmacytoma cell line, but could not when the promoter was methylated. In this context, early B cell factor (EBF), a transcription factor required for B lymphopoiesis, potentiated activation of mb-1 by Pax5. EBF and the basic helix-loop-helix transcription factor E47 each contributed to epigenetic modifications of the mb-1 promoter, including CpG demethylation and nucleosomal remodeling. EBF function was enhanced by interaction with the transcription factor Runx1. These data suggest a molecular basis for the hierarchical dependence of Pax5 function on EBF and E2A in B lymphocyte development.

Animals↗
PubMed2004

Identification of beta-arrestin2 as a G protein-coupled receptor-stimulated regulator of NF-kappaB pathways.

Norepinephrine released by the sympathetic nerve terminals regulates the immune system primarily via its stimulation of beta(2)-adrenergic receptor (beta(2)AR), but the underlying molecular mechanisms remain to be elicited. Beta(2)AR, a well-studied G protein-coupled receptor (GPCR), is functionally regulated by beta-arrestin2, which not only causes receptor desensitization and internalization but also serves as a signaling molecule in GPCR signal transduction. Here we show that beta-arrestin2 directly interacts with IkappaBalpha (inhibitor of NF-kappaB, the key molecule in innate and adaptive immunity) and thus prevents the phosphorylation and degradation of IkappaBalpha. Consequently, beta-arrestin2 effectively modulates activation of NF-kappaB and expression of NF-kappaB target genes. Moreover, stimulation of beta(2)AR significantly enhances beta-arrestin2-IkappaBalpha interaction and greatly promotes beta-arrestin2 stabilization of IkappaBalpha, indicating that beta-arrestin2 mediates a crosstalk between beta(2)AR and NF-kappaB signaling pathways. Taken together, the current study may present a novel mechanism for regulation of the immune system by the sympathetic nervous system.

Arrestins↗
PubMed2004

Hephaestin is a ferroxidase that maintains partial activity in sex-linked anemia mice.

Hephaestin (Hp) plays an important role in intestinal iron absorption and is predicted to be a ferroxidase based on significant sequence identity to the serum multicopper ferroxidase ceruloplasmin. Here, we demonstrate that Hp has both amine oxidase and ferroxidase activity in cultured cells and primary intestinal enterocytes with the use of both gel and solution assays. The specificity of the activity is shown by immunoblotting, immunoprecipitation, and immunodepletion experiments. Surprisingly, the truncated hephaestin expressed in sex-linked anemia (sla) mice still has measurable, but decreased, oxidase activity. Molecular modeling of the truncated hephaestin suggests retention of a minimum catalytic core required for enzymatic activity. We suggest that hephaestin, by way of its ferroxidase activity, facilitates iron export from intestinal enterocytes, most likely in cooperation with the basolateral iron transporter, Ireg1.

Amine Oxidase (Copper-Containing)↗
PubMed2004

Determination of vitreous, aqueous, and plasma concentration of orally administered voriconazole in humans.

OBJECTIVE: To investigate the penetration of voriconazole, a new-generation triazole antifungal agent, into the vitreous and aqueous humor after oral administration. METHODS: A prospective, nonrandomized clinical study included 14 patients scheduled for elective pars plana vitrectomy surgery between December 1, 2002, and February 28, 2003, at the Cullen Eye Institute, Houston, Tex. Aqueous, vitreous, and plasma samples were obtained and analyzed from 14 patients after oral administration of two 400-mg doses of voriconazole taken 12 hours apart before surgery. Assays were performed by means of high-performance liquid chromatography. RESULTS: Mean +/- SD voriconazole concentrations in plasma (n = 14), vitreous (n = 14), and aqueous (n = 11) were 2.13 +/- 0.93 microg/mL, 0.81 +/- 0.31 microg/mL, and 1.13 +/- 0.57 microg/mL, respectively. Mean +/- SD sampling times after oral administration of the second voriconazole dose for plasma, vitreous, and aqueous were 2.4 +/- 0.6 hours, 3.0 +/- 0.5 hours, and 2.9 +/- 0.5 hours, respectively. The percentages of plasma voriconazole concentration achieved in the vitreous and aqueous were 38.1% and 53.0%, respectively. Mean vitreous and aqueous minimum inhibitory concentrations for 90% of isolates (MIC(90)) were achieved against a wide spectrum of yeasts and molds, including Aspergillus species and Candida species, along with many other organisms. CONCLUSIONS: Orally administered voriconazole achieves therapeutic aqueous and vitreous levels in the noninflamed human eye, and the activity spectrum appears to appropriately encompass the most frequently encountered mycotic species involved in the various causes of fungal endophthalmitis. Because of its broad spectrum of coverage, low MIC(90) levels for the organisms of concern, good tolerability, and excellent bioavailability with oral administration, it may represent a major advance in the prophylaxis or management of exogenous or endogenous fungal endophthalmitis.

Administration, Oral↗
PubMed2004

Intravitreal voriconazole: an electroretinographic and histopathologic study.

BACKGROUND: Voriconazole, a novel triazole antifungal agent, presents potent activity against a broad spectrum of yeast and molds. OBJECTIVE: To determine whether voriconazole could be safely used as an intravitreal agent in the treatment of fungal endophthalmitis. METHODS: Retinal toxicity of voriconazole was examined in a rodent animal model. Voriconazole solutions were serially diluted and injected intravitreally into the eyes of normal adult Sprague-Dawley rats so that the final intravitreal concentrations were 5 microg/mL, 10 microg/mL, 25 microg/mL, 50 microg/mL, and 500 microg/mL (n = 3 for each concentration group). Saline was injected into the fellow eyes of all animals as controls. Three weeks after injections, electroretinograms were measured, and eyes were subsequently enucleated for histologic examination. RESULTS: In electroretinographic studies, maximum scotopic b-wave, intensity needed for half saturation, and saturated a-wave amplitude were measured. There was no statistically significant difference in these parameters recorded between control eyes and voriconazole-injected eyes in any concentration groups. Histologic examination with light microscopy did not reveal any retinal abnormality in the eyes with 5 to 25 microg/mL of intravitreal voriconazole. In the eyes with 50 microg/mL and 500 microg/mL of voriconazole, small foci of retinal necrosis were occasionally observed in the outer retina, especially in the eyes with 500 microg/mL of voriconazole. CONCLUSIONS: Our results demonstrate that intravitreal voriconazole of up to 25 microg/mL [corrected] causes no electroretinographic change or histologic abnormality in rat retinas. This indicates that voriconazole is a safe antifungal agent for intravitreal injection in rodents and may be used in the treatment of human fungal endophthalmitis following further study.

Animals↗
PubMed2004

Intravitreal triamcinolone does not alter basal vascular endothelial growth factor mRNA expression in rat retina.

Intravitreal triamcinolone inhibits choroidal neovascularization. To investigate if vascular endothelial growth factor (VEGF) is affected, we examined VEGF expression after intravitreal triamcinolone administration in rat retina. Using in situ hybridization, we have found dense clustered VEGF mRNA signals in the retinal pigment epithelium, moderate patchy signals in the inner nuclear layer, and positive labeling in a sub-population of ganglion cells. Densitometry and northern blot analysis revealed no significant alteration of VEGF mRNA expression pattern and level 3-21 days after triamcinolone injection. Our data indicate that intravitreal triamcinolone does not affect basal VEGF mRNA expression in normal adult rat retina.

Angiogenesis Inhibitors↗
PubMed2004

[Clinical study of the treatment of acanthamoeba keratitis by penetrating keratoplasty].

OBJECTIVE: To evaluate the influence of accurate diagnosis and peri-operative management on the recurrence of acanthamoeba keratitis after penetrating keratoplasty. METHODS: A retrospective study of 18 cases of medically unresponsive keratitis in Shandong Eye Institute and Hospital that were confirmed as acanthamoeba keratitis based on laboratory examination or histopathological studies. The diagnosis of acanthamoeba keratitis was made prior to the surgery in 12 cases and delayed until histopathological results in six cases. All cases ran a course of one to four months prior to penetrating keratoplasty with lesions measuring larger than 7 mm at the time of surgery. Corresponding anti-microbial agents were given pre-operatively based on the suspected etiological agents. Corticosteroids were given to two eyes diagnosed as acanthamoeba keratitis, three eyes misdiagnosed as herpes simplex keratitis and two eyes misdiagnosed as bacterial keratitis. RESULTS: In 13 cases without recurrence (72%), 11 cases were correctly diagnosed as acanthamoeba keratitis prior to the surgery. In five cases with relapse (28%), four cases were misdiagnosed prior to the surgery. Seven cases received corticosteroid therapy more than one week in early post-operative period and four cases developed recurrence. In the four cases with relapse, two were misdiagnosed as herpes keratitis and two were misdiagnosed as bacterial keratitis. The odds ratis of the effect of two factors (misdiagnosis and using of corticosteroid in early post-operative period) on the rate of recurrence were 22 (P = 0.021) and 13 (P = 0.047), respectively. CONCLUSIONS: Penetrating keratoplasty is an effective treatment for medically unresponsive acanthamoeba keratitis. Accurate pre-operative diagnosis, appropriate peri-operative amoebicidal therapy and avoidance from the use of corticosteroid in the early post-operative period can decrease the incidence of recurrence of acanthamoeba keratitis after penetrating keratoplasty.

Acanthamoeba Keratitis↗
PubMed2003

Photoreceptor degeneration and rd1 mutation in the grizzled/mocha mouse strain.

The mocha mouse is a spontaneous mutant carrying a defective adaptor-like protein complex AP-3delta subunit. We examined retinal function and histology of the mocha mutant. We found that not only mocha homozygotes but also other littermates in the inbred strain are blind due to severe defects in both rod and cone photoreceptors on electroretinogram recordings. The functional deficit was caused by rapid, early postnatal photoreceptor degeneration. Genotyping confirmed the presence of a viral insertion of rd1 gene in the mocha strain. We conclude that rd1 allele contamination is primarily responsible for photoreceptor degeneration, and caution against behavioral tests with visual cues in the present stocks.

Alleles↗
PubMed2003

[Molecular characterization of a new mutation E122G of human ornithine transcarbamylase gene].

OBJECTIVE: To determine the molecular basis of late onset ornithine transcarbamylase (OTC) deficiency in a Chinese family of Han nationality and the exon sequences of OTC gene of this patient. METHODS: Polymerase chain reaction-single strand conformation polymorphism and direct sequencing were used to identify the mutation type. RESULTS: A missense mutation E122G in the conserved residue of exon 4 was identified which is unreported before. CONCLUSION: The E122G mutation in human OTC gene may cause late onset OTC deficiency.

Age of Onset↗
PubMed2003

[Establishment and preliminary application of screening methods for Y chromosome microdeletions in male infertility patients].

OBJECTIVE: To develop a multiplex PCR protocol, which could be suitable for routine screening of microdeletions on the Y chromosome in azoospermic and oligozoospermic male infertility patients. METHODS: Five multiplex sets were established. Eighty-seven azoospermic and oligozoospermic patients undergoing intracytoplasmic sperm injection (ICSI) in the in vitro fertilization (IVF) center and 30 azoospermic men undergoing testicular biopsy in the clinic of Urology Surgery were screened for microdeletions of Y chromosome. RESULTS: A total of 19 (16.2%) cases of microdeletions were found in 117 azoospermic and oligozoospermic patients by screening of Y chromosome microdeletions. Of these, 11 cases (18.0%) were found in 61 oligozoospermic patients, and 8 cases (14.3%) were found in 56 azoospermic patients. CONCLUSION: The multiplex PCR protocol presented in this study is an easy-to-do and reliable method for detecting microdeletions on the Y chromosome. Routine screening of microdeletions on the Y chromosome for azoospermic and oligozoospermic patients is essential.

Chromosome Deletion↗
PubMed2003

[Real-time fluorescent PCR for screening AZFc/DAZ microdeletions on the Y chromosome in male infertility patients].

OBJECTIVE: To develop a real-time fluorescent PCR protocol suitable for the routine screening of AZFc/DAZ microdeletions on the Y chromosome in azoospermic and oligozoospermic male infertility patients. METHODS: A set of real-time fluorescent PCR was established. Eighty-seven azoospermic and ligozoospermic patients undergoing ICSI in the IVF center and 30 azoospermic men undergoing testicular biopsy in the clinic of urology surgery were screened for AZFc/DAZ microdeletions of Y chromosome. RESULTS: Eleven cases (9.4%) of AZFc/DAZ microdeletions were found in 117 cases of azoospermic and oligozoospermic patients by screening of realtime fluorescent PCR. Four cases (6.6%) were found in 61 oligozoospermic patients, and 7 cases (12.5%) were found in 56 azoospermic patients. CONCLUSION: The real-time fluorescent PCR protocol presented in this study is an easy and reliable method for detection of AZFc/DAZ microdeletions on the Y chromosome, which yields identical results to those of the multiplex PCR.

Chromosome Deletion↗
PubMed2003

Safety of intravitreal voriconazole: electroretinographic and histopathologic studies.

PURPOSE: Voriconazole, a novel triazole antifungal agent, presents potent activity against a broad spectrum of yeast and molds. To determine whether it could be safely used as an intravitreal agent in the treatment of fungal endophthalmitis, retinal toxicity of voriconazole was examined in a rodent animal model. METHODS: Voriconazole solutions were serially diluted and injected intravitreally into eyes of normal adult Sprague-Dawley rats so that the final intravitreal concentrations were 5 microg, 10 microg, 25 microg, 50 microg, and 500 microg/mL (N = 3 for each concentration group). Saline was injected into the fellow eyes of each animal as controls. Three weeks after injections, electroretinograms (ERGs) were measured, and eyes were subsequently enucleated for histologic examination. RESULTS: In ERG studies, maximum scotopic b-wave, bmax intensity needed for half saturation, I0.5, and saturated a-wave amplitude were measured. There was no statistically significant difference in these parameters recorded between control eyes and voriconazole-injected eyes in any concentration groups. Histologic examination with light microscopy did not reveal any retinal abnormality in the eyes with 5 to 25 microg/mL intravitreal voriconazole. In the eyes with 50 microg/mL and 500 microg/mL voriconazole, small foci of retinal necrosis were occasionally observed in the outer retina, especially in the eyes with 500 mg/mL voriconazole. CONCLUSION: Our results demonstrate that intravitreal voriconazole of up to 25 mg/mL causes no ERG change or histologic abnormality in rat retina. This indicates that voriconazole is a safe antifungal agent that may be employed by intravitreal injection in the treatment of fungal endophthalmitis.

Animals↗
PubMed2003

[Pioglitazone hydrochloride monotherapy or in combination with sulfonylurea therapy improves glycemia control in patients with type 2 diabetes].

OBJECTIVE: To evaluate the clinical efficacy and tolerability of pioglitazone monotherapy or in combination with sulfonylurea therapy in the treatment of chinese patients with type 2 diabetes. METHODS: This 12-week study involved 117 patients with type 2 diabetes whose blood glucose was uncontrolled on a stable regimen of diet or oral sulfonylureas for at least 3 months (fasting blood glucose (FBG) 7.8-15.0 mmol/L; postprandial blood glucose (PBG) >11.1 mmol/L)). The patients received once daily pioglitazone 30 mg plus diet (Group PIO-mono) or sulfonylurea (Group PIO-SU). The fasting and postprandial plasma glucose, serum insulin, C-peptid, lipid profile, free fatty acids (FFAs) levels were measured at baseline and every 4 weeks after treatment. Results All patients showed significant improvement in glycemic control over baseline. There were 1.64%, 2.1 mmol/L, 5.2 mmol/L decrease from baseline HbA1c, FBG and PBG levels in the Group PIO-mono and 1.06%, 2.3 mmol/L, 5.4 mmol/L decrease in the Group PIO-SU after 12 weeks treatment, respectivley. Both groups experienced slight decreases in C-peptide and insulin concentrations during 12 weeks period. Both groups showed mean percent decreases in triglyceride and FFA levels(21.8% and 20.7% for PIO-mono, 22.2% and 14.5 for PIO-SU) and increases in HDL-C (21.4% for PIO-mono and 30.8% for PIO-SU), compared with baseline. pioglitazone was well tolerated. CONCLUSION: In patients with type 2 diabetes, pioglitazone monotherapy or in combination with sulfonylurea therapy significantly improves HbA1c, FBG and PBG levels and reserves the beta-cell function with beneficial effects on serum triglyceride and HDL-C levels.

Adult↗