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Biomedical subjects

Zu-guo Liu

Publications and source records attributed to Zu-guo Liu.

13 recordsLinked to original sources
PubMed2006

[Clinical observation of wound dehiscence after penetrating keratoplasty].

OBJECTIVE: To investigate the treatment of wound dehiscence after penetrating keratoplasty and to evaluate the influence of this complication on visual outcome. METHODS: A retrospective analysis of 32 patients with wound dehiscence that undergone penetrating keratoplasty in Zhongshan Ophthalmic Center from July 1997 to June 2003 was performed. All involved eyes were undergone wound repair with or without iris excision, lensectomy, intraocular lens removal, anterior vitrectomy and stage I or stage II pars plana vitrectomy with gas or silicone oil tamponade according to variable extents of host-graft wound dehiscence in individual patient. Visual outcome, transparency of graft, intraocular pressure and structure integrity of ocular posterior segment were followed-up for 6-18 months in details. These data were used to summarize the specific characteristics of this type of ocular trauma. RESULTS: Surgical outcomes were recorded as the following: 24 eyeballs were rescued, but eight of them developed phthisis bulbi. Broken or loose sutures of eyes were found in eight cases. Six cases achieved better visual acuity, all of which maintained clear grafts with normal intraocular pressure, and no vitreous hemorrhage or choroidal/retinal detachment occurred. In 14 eyes with wound dehiscence of 1/4-1/2 circle, eight cases ended with decreased visual acuity, 11 with grafts opacities, five with abnormal intraocular pressure (above or below the normal range). In eight eyes with wound dehiscence of 1/2-3/4 circle, seven cases got decreased visual acuity, five with graft opacities, seven with abnormal intraocular pressure, four with vitreous hemorrhage, and four developing choroidal/retinal detachment. In the two eyes with wound dehiscence over 3/4 circle, both resulted in graft opacities with no light perception. Vitreous hemorrhage, choroidal/retinal detachment as well as phthisis bulbi occurred due to low intraocular pressure. CONCLUSIONS: After penetrating keratoplasty, the wounds of corneal graft show tectonic instability and poor resistance to tension. Traumatic wound dehiscence after penetrating keratoplasty often complicate with intraocular content herniation, vitreous hemorrhage, and choroidal/retinal detachment. Usually, this kind of trauma is from severe injuries and prognosis is worse than the common ocular trauma.

Adolescent↗
PubMed2006

[Changes of tear film after recovery from acute conjunctivitis].

OBJECTIVE: To investigate tear film changes after recovery from acute conjunctivitis. METHODS: This study involved 73 eyes of 56 consecutive patients who had recovered from acute conjunctivitis after routine treatment in Zhongshan Ophthalmic Center between July 2002 and August 2003. Excluded other factors which could affect the stability of the tear film, tear film break up time (BUT), Schirmer I test (ST), fluorescein staining (FL) and the height of tear meniscus were measured on both recovered and healthy eyes of the patients at 3, 7, 14, 21 and 30 days after recovery. RESULTS: BUT was 14.72 s in healthy eyes, 5.23, 5.11, 7.84, 10.26 and 12.74 s in recovered eyes at 3, 7, 14, 21 and 30 days (P = 0.012, 0.018, 0.032, 0.028 and 0.122), respectively. FL scored at 2.26 in healthy eyes, 3.02, 6.23, 7.92, 6.37 and 3.53 at 3, 7, 14, 21 and 30 days in recovered eyes (P = 0.063, 0.017, 0.008, 0.024 and 0.074), respectively. ST scored at 16.30 mm in healthy eyes, 9.39, 11.48, 13.85, 21.24 and 17.40 mm, at 3, 7, 14, 21 and 30 days in recovered eyes (P = 0.025, 0.040, 0.082, 0.012 and 0.104), respectively. The height of tear meniscus was 0.62 mm in healthy eyes; it scored at 0.39, 0.32, 0.44, 0.53 and 0.58 mm at 3, 7, 14, 21 and 30 days in recovered eyes (P = 0.008, 0.015, 0.037, 0.120 and 0.182), respectively. CONCLUSIONS: Instability of tear film and transient dry eye can occur after recovery from acute conjunctivitis. However, dry eye can be avoided during the treatment of acute conjunctivitis by consideration of drug side effects to the tear film and minimizing the unnecessary use of drugs.

Acute Disease↗
PubMed2006

[Emphasis on basic research for corneal diseases].

Corneal disease is the second leading cause of blindness in China. Improvement of the diagnosis and treatment of corneal disease depends on the deepening and widening of the basic research in this area. In some fields, the research conducted in our country has reached the top level in the world. However, in general, obvious disparities exist between China and the developed countries in terms of lack of systematic research, limited financial support, the insufficiency of the quality and quantity of researchers and so on. Based upon the current situations of China, the future basic research on corneal diseases should focus on the mechanism of infectious corneal diseases, gene mutation of corneal dystrophy, corneal tissue engineering, the pathogenesis of dry eye, the reconstruction after severe chemical burns of ocular surface, the pathogenesis of ocular surface neovascularization, the prophylaxis and therapy of corneal graft rejection, etc. Other important measures to improve the basic research of corneal diseases in our country would include applying for more research funds, training high quality researchers, and strengthening the cooperation with different disciplines and with other countries.

China↗
PubMed2006

[The transfection and expression of IL-1ra gene to the rabbit cornea in situ via cation polymer mediation].

OBJECTIVE: To investigate the efficiency and safety of transfection of PEGFP-IL-1ra plasmid via cation polymer mediation (poly-ethylenimine, PEI) by injection into the corneal stroma. METHODS: Human IL-1ra cDNA fragments were cloned by RT-PCR. Plasmid PEGFP-hIL-1ra recombinants were constructed and transferred into corneal endothelial cells (CEC) via cation polymer mediation. Expression of IL-1ra mRNA and IL-1ra was detected by green fluorescent protein (GFP) and Western-blotting. In the experiment group, 20 microl preparation containing 10 microg plasmid PEGFP-hIL-1ra recombinants and PEI-in-vivo was injected into the corneal stroma of Wistar rats (n = 30). Equivalent PEI-in-vivo solution was injected into another 15 corneas as the controls. Corneas were harvested at different time points (day 1, 3, 6, 14 and 21) after injection. The changes of tissue structure and function after IL-1ra in situ transfection were studied by HE staining, transmission electron microscopy, trypan blue-alizarin red staining and immunohistochemistry. The location and intensity of IL-1ra-GFP fusion protein expression were monitored by fluorescence microscopy. RESULTS: The size of the RT-PCR product of hIL-1ra fragments was approximately 500 bp in agarose gel electrophoresis. Restrictive enzyme digestion analysis of PstI, BamHI and DNA sequence analysis showed that expression of plasmid PEGFP-hIL-1ra recombinants had been constructed successfully. Twelve hours after the transfection of PEGFP-hIL-1ra, GFP fluorescence was detected in 10% - 15% endothelial cells. IL-1ra protein (RMW: 44,000) was detected by Western-blotting. In PEGFP-hIL-1ra treated group, fluorescence was appeared at day 1 in cornea basal epithelial cells, peaked at day 6 in whole cornea, began to weaken at day 14, and only weak fluorescence remained in cornea epithelial cells at day 21. No fluorescence appeared in the control group. No significant pathologic changes could be found in HE stained cornea tissues in both transfected group and the controls. p63 immunocytochemical staining in cornea epithelium was positive in both groups. Trypan blue-alizarin red staining confirmed that there was no damage in cornea endothelial cells. IL-1ra-GFP granules could be found by transmission electron microscope in every layer of cornea in the transfected group, but none in the controls. There was no impairment in the ultrastructure of cells in both groups. CONCLUSIONS: By direct injection of PEGFP-hIL-1ra into corneal stroma and mediated by cation polymer, IL-1ra genes could be transferred and expressed in corneal tissue efficiently and safely, and might provide a novel technique of gene transfection to cornea in situ.

Animals↗
PubMed2005

Functional recovery after rhesus monkey spinal cord injury by transplantation of bone marrow mesenchymal-stem cell-derived neurons.

BACKGROUND: The treatment of spinal cord injury is still a challenge. This study aimed at evaluating the therapeutical effectiveness of neurons derived form mesenchymal stem cells (MSCs) for spinal cord injury. METHODS: In this study, rhesus MSCs were isolated and induced by cryptotanshinone in vitro and then a process of RT-PCR was used to detect the expression of glutamic acid decarboxylase (GAD) gene. The induced MSCs were tagged with Hoechst 33342 and injected into the injury site of rhesus spinal cord made by the modified Allen method. Following that, behavior analysis was made after 1 week, 1 month, 2 months and 3 months. After 3 months, true blue chloride retrograde tracing study was also used to evaluate the re-establishment of axons pathway and the hematoxylin-eosin (HE) staining and immunohistochemistry were performed after the animals had been killed. RESULTS: In this study, the expression of mRNA of GAD gene could be found in the induced MSCs but not in primitive MSCs and immunohistochemistry could also confirm that rhesus MSCs could be induced and differentiated into neurons. Behavior analysis showed that the experimental animals restored the function of spinal cord up to grade 2-3 of Tarlov classification. Retrograde tracing study showed that true blue chollide could be found in the rostral thoracic spinal cords, red nucleus and sensory-motor cortex. CONCLUSIONS: These results suggest that the transplantation is safe and effective.

Animals↗
PubMed2005

[Analysis of gene mutation in Chinese patients with Reis-Bücklers corneal dystrophy].

OBJECTIVE: To identify the mutation of the TGFBI gene in Chinese patients with Reis-Bücklers corneal dystrophy, and to study the relationship between the gene mutation and the clinical appearance. METHODS: Ten patients and 2 unaffected family members from 2 unrelated families with corneal dystrophy were studied. Molecular genetic analysis was performed on DNA extracted from peripheral leucocytes, and exons 4 and 12 of the TGFBI gene were amplified by polymerase chain reaction for direct sequencing. RESULTS: Both pedigrees showed an autosomal dominant inheritance. The clinical appearance of the cornea consisted of fine granular, subepithelial opacities which spread and become confluent with time, and resembled geographic type of Reis-Bücklers corneal dystrophy. Direct sequencing of all affected members revealed a G-to-T transition at codon 124 (CGC to CTC), producing R124L mutation of TGFBI gene. CONCLUSIONS: R124L mutation of the TGFBI gene is found in two Chinese families with Reis-Bücklers corneal dystrophy. The phenotype of Reis-Bücklers corneal dystrophy in both families belongs to the geographic type. Molecular genetic approach may be useful for the proper diagnosis of this type of corneal dystrophy.

Adolescent↗
PubMed2005

[Transplantation of 3H-thymidine-labeled human bone marrow-derived mesenchymal stem cells in mdx mice].

OBJECTIVE: To investigate the feasibility of using human bone marrow-derived mesenchymal stem cells (hBM- MSCs) for repairing the skeletal muscle sarcolemma lesions in mdx mice and characterize the distribution of the transplanted hBM-MSCs. METHODS: Eighteen 8- to 10-week-old immunosuppressed mdx mice received transplantation with 1x10(7) of hBM-MSCs (the fifth passage) with 3H-thymidine (3H-TdR) labeling by injection of the cells into the tail vein. The mice were killed at 24 h, 48 h, 2 weeks, and 1, 2 and 4 months after the transplantation, respectively, to measure the radioactivity in the tissues and organs. Dystrophin expression on the sarcolemma was detected by immunofluorescence analysis. RESULTS: One month after transplantation, the mice with cell transplantation showed greater radioactivity in most of the tissues and organs than the control mice, especially in the bone marrow, liver and spleen. The radioactivity was then gradually lowered but in the skeletal muscle, the radioactivity increased progressively since 2 weeks after transplantation, reaching the peak of 27.65+/-3.53 Bq/mg at 1 month. Compared with that in the control mice, the radioactivity in the bone marrow and skeletal muscle was persistently higher in mice with cell transplantation 1 month after transplantation. No dystrophin-positive cells were found in the mdx mice at 2 weeks but detected at 1 month. The percentage of dystrophin-positive fibers in each section ranged from a 6.6% (1 month) to 8.9% (4 months). CONCLUSIONS: hBM-MSCs engrafted in immunosuppressed mdx mice may differentiate into skeletal muscle cells to repair the pathological lesion of the skeletal muscle sarcolemma. The hBM-MSCs reside mainly in the bone marrow, liver and spleen in the early stage following transplantation, homing into the bone marrow and skeletal muscle later.

Animals↗
PubMed2005

[Gene reversion of induced differentiation of adult human bone marrow-derived mesenchymal stem cells into neuron-like cells].

OBJECTIVE: To observe gene reversion during differentiation of human adult bone marrow-derived mesenchymal stem cells (MSCs) into neuron-like cells induced by Shenqiye. METHODS: The MSCs were separated, cultured and expanded in the culture medium and induced to differentiate into neuron-like cells with Shenqiye. The expressions of neuron-specific enolase (NSE), neurofilament (NF), and glial fibrillary acidic protein (GFAP) were detected by immunocytochemical method, and the changes of 10 genes of the cells after differentiation were detected by reverse transcriptional PCR. RESULTS: The MSCs exhibited neuronal phenotype when treated with Shenqiye and the neuron-like cells were positive for expressions of NSE and NF but not for glial astrocyte marker GFAP. After withdrawal of Shenqiye from the medium, the neuron-like cells were reversed to MSC, flat or spindal in morphology. The gene expression profiles of the redifferentiated cells were similar to those of undifferentiated MSCs. CONCLUSION: Shenqiye can induce MSC differentiation into neuron-like cells during and after which gene reversion may occur.

Animals↗
PubMed2005

[Effect of doxycycline on inflammation-related cytokines and apoptosis in human conjunctival epithelial cells].

OBJECTIVE: To evaluate the effects of doxycycline on the regulation of intercellular adhesion molecule-1 (ICAM-1, CD54), interleukin-1beta (IL-1beta), human leukocyte antigen DR (HLA-DR) and apoptosis in human conjunctival epithelial cells. METHODS: Human primary conjunctival epithelial cells were isolated and cultured from donors and identified by immunohistochemistry. Cultured epithelial cells were treated with either 0 U/ml IFN-gamma, 300 U/ml IFN-gamma, 300 U/ml IFN-gamma with 10 microg/ml doxycycline, 300 U/ml IFN-gamma with 20 microg/ml doxycycline, 300 U/ml IFN-gamma with 40 microg/ml doxycycline or 300 U/ml IFN-gamma with 100 microg/ml dexamethasone for 24 hours. The amount of CD54, HLA-DR and IL-1beta was measured by flow cytometry and western blot analysis. Apoptosis was evaluated by flow cytometry after the cultured epithelial cells were treated for 72 hours. RESULTS: Cultured conjunctival epithelial cells can express CD54 and IL-1beta. IFN-gamma increased the amount of CD54 and IL-1beta (P < 0.01). Doxycycline and dexamethasone inhibited the IFN-gamma induced increase of express of CD54 and IL-1beta of cultured conjunctival epithelial cells, and the inhibiting effect was dependent on the concentration of doxycycline (P < 0.01). Very little HLA-DR and apoptosis were detected before and after treatment with IFN-gamma. CONCLUSION: Doxycycline can suppress the expression of inflammatory cytokine such as CD54 and IL-1beta, which suggests that doxycycline may be a potent drug for the treatment of ocular surface inflammatory disease.

Anti-Bacterial Agents↗
PubMed2004

[A clinical study of amniotic membrane transplantation for severe eye burns at the acute stage].

OBJECTIVE: To investigate the possibility of ocular surface reconstruction with amniotic membrane in the acute stage of burn injury, to compare the results using fresh and preserved amniotic membranes and to evaluate the surgical methods and their effects. METHODS: Consecutive patients of whole corneal burn above degree III with complete destruction of the limbus were divided into two groups to receive amniotic membrane transplantation (8 eyes of 8 patients with fresh amnion, 12 eyes of 11 patients with preserved one) or lamellar keratoplasty (24 eyes of 22 patients). The follow-up period was 12 to 26 months with an average of (15 +/- 2) months. RESULTS: The ocular surface became stabilized after the transplantation of amniotic membrane. In eyes treated with fresh amniotic membrane, the corneal surface was epithelized immediately. In eyes treated with preserved amniotic membrane, the corneal surface was epithelized only after 2 - 3 weeks. Lamellar keratoplasty was performed in 3 of 12 eyes with preserved amnion transplantation because the amnion was dissolved due to persistent epithelial defects. Amnions were absorbed with time and superficial neovascularization followed in the corneal surfaces. Seven of eight transplanted fresh amnions were absorbed within 2 to 8 months [mean time (4.3 +/- 0.8) months], and 10 of 12 preserved amnions were absorbed within 1 to 3 months [mean time (2.0 +/- 0.3) months]. The difference was statistically significant (t = 4.22, P < 0.01). The conjunctival surface was successfully reconstructed with amniotic membrane at the acute stage of burn injury. Moderate symblepharon occurred in one case only. Corneal dissolution never occurred in all patients who received lamellar keratoplasty, but recurrent erosion of corneal epithelium occurred in the grafts and corneal neovasularization developed eventually. Corneal graft had to be performed again on four eyes and symblapharonplasty had to be performed on seven eyes. Mild to medium symblepharon was observed in 5 of 24 eyes received lamellar keratoplasty. Visual acuity could be maintained at hand movement in eyes treated with amniotic membrane transplantation without secondary glaucoma and cataract. Visual acuity was figure counting in most cases with lamellar keratoplasty. CONCLUSIONS: Amniotic membrane transplantation (especially using a fresh membrane) can effectively reduce the inflammation of the cornea at the acute stage of burn injury, can prevent corneal ulcer and perforation and can make the stabilization process faster. It can also decrease corneal neovascularization as well as establish better conditions for successful keratoplasty.

Acute Disease↗
PubMed2003

[Clinical characteristics of patients with dry eye syndrome].

OBJECTIVE: To learn the clinical characteristics of patients with dry eye syndrome. METHODS: The following items were recorded in 115 patients (229 eyes) with dry eye, including symptoms, causation, systematic diseases, slit-lamp examination, tear break-up time, basal and reflex Schirmer's test, vital staining (fluorescent and rose bangle) and meibomian gland dysfunction examination. Rheumatoid factor and auto-antibody detection were performed in Sjögren's syndrome suspected patients. RESULTS: Aqueous tear deficiency (ATD, 48.7%) ranked the most common type, followed by over-evaporation dry eye (34.8%), mixed type (13.9%) and conjunctivochalasis (3.5%). In all the causes of the dry eye, about 11.3% had Sjögren syndrome (SS). Females suffering from dry eye were more than males, especially SS. Dryness was the most common symptom (84.0%), especially in ATD patients, then followed by ocular fatigue (72.0%), foreign body sensation (64.0%) and impairment of vision (56.0%). The ocular irritation was more severe in meibomain gland dysfunction (MGD) patients than in ATD patients. Among the results of tear break-up time (BUT), rose bangle (Rb) staining and fluorescent (Fl) staining in all types of dry eye, significant relationship was found among them, especially between Rb and Fl score (r = 0.612, P = 0.000). SS patients had much more severe abnormality in all the four signs than non-SS aqueous tear deficiency (NSTD) and MGD patients. However, in the comparisons of BUT, Rb and Fl between NSTD and MGD patients, there were no significant differences. CONCLUSION: Symptoms combined with examinations of BUT, Schirmer's test, Fl and Rb staining and meibomian gland function are the necessary means to diagnose most of the dry eye patients.

Adolescent↗