Biomedical subjects
Publications and source records attributed to G Feng.
Dendrobium drug, a rare medicinal herb, reproduces differcut for growth environment to lead rare resources. By studying of cultivation for many many years in Fuliu mountain area, authors had found out the cultivated method simulating the habitat of wild Dendrobium flexicaule. The results could supply a basis for its development and utilization.
PURPOSE: To study the healing of the corneal endothelial cells in rabbit corneal alkali wounds. METHODS: 26 New Zealand white rabbits were used. A alkali wound was created with a round filter paper, 8 mm in diameter, which was soaked in 0.5 N NaOH for 5 seconds and was placed centrally on the cornea for 60 seconds. The rabbits were killed in 20 minutes; 1, 2, 6, 12 h; 1, 2, 3, 5, 7, 10, 14, 30 days after injury. The corneal endothelium was examined in the light microscope using a lizarin red S-trypan blue staining method. RESULTS: Twenty minutes after the wound, the corneal endothelial cells were destroyed. 72 hours following the wound, the endothelial cells surrounding the burns became larger, irregular and started to migrate onto the denuded descemet's membrane. The endothelial cells covered the burn with the spindle-shaped cells 7 days after wound. CONCLUSION: The endothelial damage is healed by the division and migration of remaining endothelial cells at the margin of the wound, which has some characters of fibroblast.
PURPOSE: To investigate the intraocular growth and biological characteristics of mice embryonic stem cells in nude mice. METHODS: Murine embryonic stem cells (D3 cell line) were cultured and maintained in an undifferentiated state in vitro, then transplanted into the anterior chamber of nude mice. Mophological and immunohistochemical examinations were implemented. RESULTS: Two to three days after transplantation, yellow-white floating granules, sheets and masses were seen inside the anterior chamber and vitreous cavity, and enlarged gradually. 14-20 days later, the mice were executed. Morphological examination showed that there were undifferentiated cells and some round or polygonal differentiated cells in anterior chamber and vitreous cavity. The morphology of these differentiated cells were similar to that of the retina. The cells were highly positive in NSE staining. CONCLUSION: The transplanted embryonic stem cells could grow in the eyes of nude mice with tendency to differentiate into neurons and retina-like structure.
PURPOSE: To modify the isolation of human retinal pigment epithelial (RPE) cells and to increase the purification and production of cultured RPE cells. METHODS: The human eyecups were fixed on a rubber holder. After digestion by trypsin, RPE cells were collected, then cultured and identified by morphology, immunohistochemistry and electron microscopy. RESULTS: The cultured RPE cells grew actively in the early stage with transparent nucleus and abundant melanin particles in cytoplasm. These cells were positive in DOPA oxidase reaction and in anti-pancytokeratin antibody staining. Cellular microvilli and tight junctions could be seen through transmission electron microscopy. CONCLUSION: We developed a rubber holder to fix the eyecup. Using this holder, more and purer cultured RPE cells can be obtained. These cultured RPE cells are similar to those in vivo in morphology and immunohistochemical staining.
PURPOSE: To evaluate the techniques of rapid and accurate diagnosis of chlamydial conjunctivitis. METHODS: Total 100 conjunctivitis patients (200 eyes) were studied. Twenty-two of 100 cases were diagnosed as chlamydial conjunctivitis. The infected epithelia were scraped from tarsal conjunctiva of both eyes and stained separately with Giemsa (100 cases) and immunofluorescence (anti-chlamydial antigen monoclonal antibody, 100 cases). RESULT: In immunofluorescent staining, 38 cases were seen positive staining and 62 were negative. In Giemsa staining, 29 were positive, and 71 were negative. In 22 cases with clinical diagnosis of chlamydial conjunctivitis, 13 cases were confirmed, and 9 were excluded by immunofluorescent staining. Technically, immunofluorescent and Giemsa stain takes 45 and 40 minutes, respectively. CONCLUSION: Comparing to Giemsa stain, 38 of 100 scraping specimens were positive (38%) by immunofluorescent staining, 29 of 100 per cent were positive by Giemsa staining. Giemsa staining takes 5 minutes less than immunofluorescent staining (40 versus 45 minutes), however, the positive staining in immunofluorescent staining is much easier to be recognized than Giemsa staining.
PURPOSE: To observe the morphologic changes of epithelium in the alkali wounds at the central corneal of rabbits. METHODS: 38 rabbits weighing 2.5 kg were used. A alkali wound of the corneas was performed in the right eye of 38 New Zealand white rabbits with round filter paper, 8 mm in diameter, which were soaked in 0.5 mol/L NaOH for 5 seconds and then were placed centrally on the cornea for 60 seconds. The corneal burns were examined and photographed after the staining of 2% fluoresent staining with a slit lamp every day. The excised corneas were examined in the light microscope, electron microscope. RESULTS: The epithelial cells had rapidly disappeared in the burned area. The epithelial cells regrowth started at 8 hours following the burn, and 1-2 layers epithelial cells covered the burned area by 24 hours. The epithelial defects occured again on the 4th day. The desmosome and microvilli of the regenerating epithelium had a reduced number. There was no basement membrane between the regenerating epithelium and the strom. There were increased intercellular spaces between the regenerating epithalial cells. CONCLUSION: The epithelial healing were achieved through the division and migration of epithelial cells at the margin of the wound in rabbit central corneal alkali wound. The decrease of the junctions and the increase of intercellular spaces between the regenerating epithalial cells may be responsible for the second epithelial defects.
OBJECTIVE: The serotonin transporter gene (SERT) plays an important role in the serotonin uptake into neurons. This paper reports a population and association study among the Han Chinese. METHODS: DNA were extracted from peripheral blood samples of 50 patients with bipolar disorder (DSM-IIIR), 170 unrelated healthy Han Chinese individuals and 10 healthy trios for polymerase chain reaction. The VNTR locus was amplified and PCR products were separated on the 2% agrose gel. RESULTS: All the three alleles(9,10 and 12 copies of repeat unit) reported in other studies were observed in this study with frequency 0.0029, 0.0676 and 0.9294, respectively. Four genotypes distributed in Caucasian: 12/12, 12/10, 12/9 and 10/10 were also found in the Han Chinese population. A significant difference in the allele frequency between the Han Chinese and Caucasian populations was found(P 0.000000001). No disequilibrium was observed after checking the Hardy-Weinberg equilibrium (P=0. 9995). The hereditary stability of this locus in accordance with the rules of Mendelian inheritance was demonstrated in the analysis of ten trios. In addition, a significant increase of frequency of the allele 10 in female patients with bipolar disorder was found (P=0. 043). CONCLUSION: The data of association study might indicate a different mechanism of aetiology of bipolar disorder in male and female.
Glycine receptors are anchored at inhibitory chemical synapses by a cytoplasmic protein, gephyrin. Molecular cloning revealed the similarity of gephyrin to prokaryotic and invertebrate proteins essential for synthesizing a cofactor required for activity of molybdoenzymes. Gene targeting in mice showed that gephyrin is required both for synaptic clustering of glycine receptors in spinal cord and for molybdoenzyme activity in nonneural tissues. The mutant phenotype resembled that of humans with hereditary molybdenum cofactor deficiency and hyperekplexia (a failure of inhibitory neurotransmission), suggesting that gephyrin function may be impaired in both diseases.
Nicotinic acetylcholine receptors (AChRs) are clustered at high density in the postsynaptic membranes of skeletal neuromuscular junctions and cholinergic interneuronal synapses. A cytoplasmic protein, rapsyn, is essential for AChR clustering in muscle. Here, we asked whether rapsyn mediates neuronal AChR clustering at cholinergic synapses in a mammalian sympathetic ganglion, the superior cervical ganglion (SCG). Several observations supported this possibility: (1) AChR clusters containing the alpha3-5 and beta2 subunits, homologs of the muscle AChR subunits, are present at SCG synapses; (2) rapsyn RNA is readily detectable in the SCG; and (3) expression of recombinant rapsyn in heterologous cells induces aggregation of coexpressed neuronal AChR subunits. However, rapsyn protein was undetectable at ganglionic synaptic sites. Moreover, aggregates of neuronal AChRs induced in heterologous cells by full-length rapsyn remained intracellular, whereas rapsyn-induced clusters of muscle AChRs reached the cell surface. Additional studies revealed a second rapsyn RNA species in SCG generated by alternative splicing and competent to encode a novel short rapsyn isoform. However, this isoform clustered neither neuronal nor muscle AChRs in heterologous cells. Most telling, the number, size, and density of AChR clusters in SCG did not differ significantly between neonatal mice bearing a targeted mutation of the rapsyn gene and littermate controls. Thus, rapsyn is dispensable for clustering of ganglionic neuronal nicotinic AChRs.
To explore a new way of utilizing intervential treatment to effectively decrease the portal hypertension, the animal models of liver cirrhosis accompanying portal hypertension were set up by intraportal vein injection of suspensions of Bletilla striata to 10 rabbits by means of prospective investigational method. The catheter filled with heparin solution was remained in theportal vein for infusion of drugs. Three weeks later, DDPH solution was injected into the portal vein via the catheter to determine its effect of decreasing portal vein pressure and its influence of peripheral blood pressure and heart rate. At the same time, other 10 rabbits with liver cirrhosis associated with portal hypertension were subjected to the injection of DDPH solution via the ear vein served as control group. The results showed that administration of DDPH by portal vein could rapidly, safely and effectively decrease the portal hypertenive pressure without side effects and partially reverse liver cirrhosis, as compared with injection of DDPH via peripheral veins. It was concluded that DDPH exerted its alpha 1-adrenoceptor blocking and calcium antagonistic effects, thereby significantly reduce the portal hypertension. Injection of DDPH via portal vein is a completely new and relaible method for the treatment of liver cirrhosis with portal hypertension.
To begin unraveling the functional significance of calcium channel diversity, we identified mutations in Dmca1D, a Drosophila calcium channel alpha1 subunit cDNA that we recently cloned. These mutations constitute the l(2)35Fa lethal locus, which we rename Dmca1D. A severe allele, Dmca1D(X10), truncates the channel after the IV-S4 transmembrane domain. These mutants die as late embryos because they lack vigorous hatching movements. In the weaker allele, Dmca1D(AR66), a cysteine in transmembrane domain I-S1 is changed to tyrosine. Dmca1D(AR66) embryos hatch but pharate adults have difficulty eclosing. Those that do eclose have difficulty in fluid-filling of the wings. These studies show that this member of the calcium channel alpha1 subunit gene family plays a nonredundant, vital role in larvae and adults.
OBJECTIVE: Experimental fetal surgery has been a popular way to study growth and development and wound healing. The rabbit continues to be a reasonable animal model. The key to success of the experiment lies in keeping the survival rate of the operated animal above 80 percent. In this paper a simple experimental method for fetus surgery in rabbits is described. METHODS: Intravenous thiopental sodium is used for general anesthesia. Surgery is performed inside the uterus through hysterotomy or with the caudal part of the fetus out of the uterus. Amniotic fluid is restituted by instillation of warm saline at 37 degrees C. Special care is taken to suture the amnion. RESULTS: Using these techniques carefully, we have had 90 percent of success in fetal surgery experiment. CONCLUSION: A technically simple procedure has been developed for fetal rabbit surgery.
To assess the effect of different embolic agents in curing craniofacial tumors and vascular diseases, 21 patients who were treated by intra-arterial embolization were divided into three groups: gelfoams, bletilla striatas and coils. The results showed that 8 cases of preoperative patients in gelfoams group had a good effect and bleeding were reduced during operation. One patient had vascular recanalization at 1 month after embolization with gelfoam. All patients in bletilla striatas had ideal effect. In coils group, collateral supplying arteries were found in 3 patients at once after embolization and the others had a good effect. In conclusion, craniofacial tumors and vascular diseases were fit to embolotherapy. The selection of embolic agents should be gelfoam in preoperative embolization and bletilla striata in palliative treatment There were not severe complications.
OBJECTIVE: To investigate the changes of thromboxane A2 receptors and the influence of their antagonist phenol red, and to study in molecular level the mechanism of action of thromboxane A2 in acute lung injury. METHODS: Acute lung injury model of rats was produced by oleic acid, and phenol red (5 mg/kg, 50 mg/kg) was injected via vein 5 minutes before oleic acid injection. Changes of thromboxane A2 receptors and their mRNA expression in the lung were determined at 6 hours after oleic acid injection. RESULTS: Down-regulation of thromboxane A2 receptors were observed, but their mRNA transcription increased significantly in the lung after oleic acid injection. The injection of phenol red before oleic acid could induce down-regulation of thromboxane A2 receptors and abolish the increase of their mRNA transcription after oleic acid injection. Phenol red could reduce LBI, RLW and improve PaO2. Histological examination of lung tissues demonstrated that the degree of lung injury had been reduced significantly. CONCLUSION: Thromboxane A2 plays an important role plays in pathological processes of acute lung injury. Phenol red in vivo could effectively reduce severity of acute lung injury by blocking thromboxane A2 receptors and regulating the expression of thromboxane A2 receptors.
OBJECTIVE: To evaluate Bletilla striata as a vascular embolizing agent in interventional treatment of primary hepatic carcinoma. METHODS: We made a vascular embolizing agent from a Chinese medicinal herb, Bletilla striata (bai ji). From October 1991 to January 1995, 56 patients with primary hepatic carcinoma were treated by hepatic arterial chemoembolization with Bletilla striata angioembolus, and 50 patients with primary hepatic carcinoma who were treated by conventional gelfoam embolization served as controls. All patients were followed up for 10-48 months. RESULTS: Embolization with the Bletilla striata powder produced extensive and permanent vascular obstruction, resulting in marked shrinkage of the tumor and significant decrease of serum alpha fetoprotein (AFP) level. After embolization, less collateral circulation formed later. The treatment interval was prolonged to an average of 7 months. The 1-, 2- and 3-year survival rates were 81.9%, 44.9%, and 33.6%, respectively, with a mean survival period of 19.8 months. All the clinical parameters were better than those in the control group treated by conventional gelfoam embolization. CONCLUSION: Bletilla striata angioembolus is a good vascular embolizing agent for treating PHC.
OBJECTIVE: With retinoblastoma (Rb) cell lines cultured in vitro to screen chemotherapeutic drugs that are effective on Rb. METHOD: Sensitivity experiments were performed with the 3, -4, 5 Dimethyliazol-2, 5 diphenyl tetrazolium bromide (MTT) assay for the drugs: dactinomycin (DACT), vincristine (VCR), VM-26, daunorubicin (DNR), DDP, bleomycin (BLMA5) against the tumor cell lines of SO-Rb50 and SO-Rb70. RESULTS: The IC(50) values (microg/ml) in order at 48 hours of the above pharmaceuticals against SO-Rb50 were respectively 0.0004, 0.0016, 0.0389, 0.047, 0.29, 0.44, and those at 72 hours were 0.00025, 0.00081, 0.0151, 0.0192, 0.097, 0.11. And the IC(50) values (microg/ml) in order at 48 hours of the above pharmaceuticals against SO-Rb70 were respectively 0.00065, 0.00149, 0.0282, 0.043, 0.37, 0.215, and those at 72 hours were 0.00042, 0.00082, 0.0146, 0.0176, 0.035, 0.084. CONCLUSION: The tumor cell lines of SO-Rb50 and SO-Rb70 were sensitive to the above six pharmaceuticals. By their IC(50) values, the sensitivity order to the drugs, from higher to lower, was DACT, VCR, VM-26, DNR, DDP, BLMA5.
PURPOSE: To compare the differences of chromosome aberration among 3 cloning cells (MC2, MC3 and MC4) of SO-Rb50 cell line. METHOD: G-banding and karyotype analysis were performed on the 11th passage cells of MC2, MC3 and MC4 cell strains. RESULTS: Both numerical abnormal and structural aberrations of chromosomes could be observed in these 3 cloned cell strains. Diploid cells had the preponderance over the aneuploid cells. However, some cells showed pseudiploid karyotypes. Several kinds of structural chromosome aberrations were observed. The chromosome aberrations in the same passage of different cell strains were different. Aberration of chromosome 13 was rare and the aberration feature were different in 3 cloned cell strains. Five marker chromosomes were identified. M1, t(1;1) qterp35::q24-ter could be found in all cell strains. Other markers were seen in different cell strains respectively. In our experiment, two marker chromosome in chromosome 2, M4 and M5, were found in SO-Rb50 cell line for the first time. CONCLUSION: Chromosome aberrations were different with different cloned cell strains. Combined with formerly study in SO-Rb50 cell line, we found the chromosome aberration had dynamic changes during the long-term culture in vitro. We suggest that aberration of chromosome 13 is not the only cause of Rb; aberration of chromosome 1, a common event in some neoplasias as well as in SO-Rb50, plays a meaningful role in the immortalization of this cell line; other aberrations observed in our experiment could be considered as evidences of genomic instability of the cell strains and presumably enhance the growth potential of the cells in which they develop.
PURPOSE: To observe the pathologic change of the endogenous endophthalmitis of cryptococcus neoformans. METHODS: Light and electron microscope were used. RESULT: The choroid was focally tumor-like by an inflammatory cells infiltrate, which consisted of multinucleated gicant, epithelioid cells and lymphocytes. Special stains (Grocott's methnamine silver, PAS, alcian blue) and electron microscope disclosed the budding form of cryptococcus neoformans. CONCLUSION: The morphologic examinations are only an effectivel method of diagrosing the endogenous endophthalmitis of cryptococcus neoformans.