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Biomedical subjects

C C Chan

Publications and source records attributed to C C Chan.

At least 145 records · Page 8Linked to original sources
PubMed1999

Inhibition of experimental melanin protein-induced uveitis (EMIU) by targeting nitric oxide via phosphatidylcholine-specific phospholipase C.

Experimental melanin protein-induced uveitis (EMIU) is an autoimmune uveitis induced by immunization with uveal melanin protein. Fas and FasL enhancement is reported in rats with EMIU. Tricyclodecan-9-yl-xanthogenate (D609), a specific inhibitor of phosphatidylcholine-specific phospholipase C, inhibits inducible nitric oxide synthase (iNOS) induction. In two independent experiments, 35 Lewis rats with EMIU received either D609 or PBS daily. The eyes and draining lymph nodes were collected for histology, analyses of nitrite, peroxide, and superoxide dismutase, Fas and FasL immunochemistry, in situ hybridization for iNOS mRNA and in situ apoptosis detection at the peak of the disease. Both experiments showed significant inhibition of EMIU by D609. Decreases in nitrite and peroxide, increase of superoxide dismutase and lower expressions of iNOS mRNA were found in D609-treated, as compared to PBS-treated eyes. There was mild enhancement of Fas and FasL in the eyes and lymph nodes of D609-injected animals. DNA fragmentation was increased in the lymph nodes of D609-treated rats. We conclude that iNOS activation is responsible for NO production in eyes with EMIU. The suppressive effect of D609 on EMIU may result from scavenging NO and activating apoptosis previously inhibited by NO along with other anti-inflammatory effects.

Animals↗
PubMed1999

Morphologic and genetic analysis of retinal angioma associated with massive gliosis in a patient with von Hippel-Lindau disease.

We report morphologic and genetic analysis of bilateral retinal angiomas in a 35-year-old patient with von Hippel-Lindau (VHL) disease. Enucleation of both eyes revealed extensive intraocular tumor. Whereas the right eye demonstrated large amounts of retinal angioma tissue, the left eye showed small areas of retinal angioma associated with massive diffuse retinal gliosis. Genetic analysis of the angioma showed allelic deletion of the VHL gene locus, suggesting that the origin of the angiomas was directly related to the patient's underlying VHL disease. Genetic analysis of the pleomorphic glial proliferation showed no allelic VHL gene deletion, which is consistent with the assessment that the glial component represents a reactive process. Apoptosis detected by TUNEL revealed lack of DNA fragmentation in the angioma; in contrast, many positive signals were found in the massive gliosis. We confirmed that the abnormal VHL genes were located in the "stromal" cells of the retinal angioma. Massive gliosis in VHL disease is a true reactive retinal gliosis.

Adult↗
PubMed1999

Subretinal fibrosis and choroidal neovascularization in Vogt-Koyanagi-Harada syndrome.

BACKGROUND: To describe clinical findings of subretinal fibrosis and choroidal neovascularization in patients with Vogt-Koyanagi-Harada (VKH) syndrome. METHODS: We retrospectively reviewed 75 medical records of patients with VKH seen at the National Eye Institute, Bethesda, Maryland between 1978 and 1996. Recorded data included age, gender, race, duration of disease, extraocular manifestations, best-corrected visual acuity, slit-lamp biomicroscopy, retinal examination, retinal photographs and fluorescein angiograms. We sought features that correlated with the visual outcome. RESULTS: Thirty of 75 (40%) patients developed subretinal fibrosis. Eleven patients (14.7%) had choroidal neovascularization. Presence of subretinal fibrosis was associated with a longer duration of the disease (42.6 vs 19.1 months, P = 0.07). Patients with subretinal fibrosis had worse visual acuity than those without subretinal fibrosis (26.2 vs 57.3 ETDRS letters read, P < 0.001) after adjusting for duration of disease (P = 0.021), degree of vitreous haze (P = 0.074), and use of immunosuppressive therapy (P = 0.008). CONCLUSIONS: Presence of subretinal fibrosis in patients with VKH is associated with a poor visual prognosis. The diagnosis of choroidal neovascularization and subretinal fibrosis presents a challenge in the management of this disease.

Adult↗
PubMed1999

Translocation of chromosomes 11 and 22 in choroidal metastatic Ewing sarcoma detected by fluorescent in situ hybridization.

PURPOSE: To describe a patient with metastasis of Ewing sarcoma to the choroid and the molecular genetics of the tumor. METHODS: A 26-year-old woman with metastatic Ewing sarcoma developed large choroidal masses in the left eye and died 2 months later. Autopsy of the eyes was performed. Dual-color fluorescent in situ hybridization was used to detect genetic alteration in the ocular tumor with EWS and FLI-1 probes. RESULTS: Histopathology confirmed choroidal metastatic Ewing sarcoma. Molecular analysis showed chromosomal translocation t(11;22)(q24;q12) or EWS/FLI-1 rearrangement in the malignant cells of the eye. CONCLUSIONS: Ewing sarcoma can rarely metastasize to the uvea. Molecular detection of the t(11;22)(q24;q12) translocation in Ewing sarcoma is valuable in the differential diagnosis of small round cell tumors.

Adult↗
PubMed1999

Cyclooxygenase-2 inhibition by rofecoxib reverses naturally occurring fever in humans.

Cyclooxygenase (COX) exists as constitutive (COX-1) and inducible (COX-2) isoforms. Nonsteroidal antiinflammatory drugs (NSAIDs) such as ibuprofen and diclofenac inhibit both COX-1 and COX-2. The role of COX-2 in the genesis of fever in monkeys and humans was examined with use of the specific COX-2 inhibitor rofecoxib. Rofecoxib was administered to monkeys made febrile by 6 microg/kg intravenous lipopolysaccharide. Induced pyrexia was followed by oral rofecoxib (1 or 3 mg/kg), diclofenac (3 mg/kg), or vehicle. Rofecoxib and diclofenac rapidly reversed the elevated temperature (P < .05 versus vehicle for 3 mg/kg rofecoxib and diclofenac at 70 to 90 minutes after dosing). A single-dose, parallel-group, double-blind randomized trial was conducted in 94 patients with fever caused by a viral-type illness. Mean baseline temperature was similar for all groups (-38.5 degrees C). Patients received oral doses of 12.5 mg rofecoxib, 25 mg rofecoxib, 400 mg ibuprofen, or placebo and the mean +/- SE change in oral temperature at 4 hours after dosing was -0.97 degrees C +/- 0.11 degrees C, -1.19 degrees C +/- 0.09 degrees C, -1.20 degrees C +/- 0.11 degrees C, and 0.01 C +/- 0.17 C, respectively (P < .001 for active treatments versus placebo). Specific inhibition of COX-2 by rofecoxib results in antipyretic activity in monkeys and humans comparable to dual COX-1/COX-2 inhibitors such as diclofenac or ibuprofen. The data support the hypothesis that it is the COX-2 isoform that is primarily involved in the genesis of fever in humans.

Administration, Oral↗
PubMed1999

Comparison of invasive and noninvasive tests for detecting Helicobacter pylori infection in bleeding peptic ulcers.

BACKGROUND: Eradication of Helicobacter pylori infection has been shown to prevent recurrent bleeding from peptic ulcers. However, the detection rate for H pylori infection seems to be underestimated in this group of patients and has been scarcely investigated. METHODS: Eighty patients with bleeding peptic ulcer were studied for evidence of H pylori infection. Seventy-seven of these patients were enrolled as having H pylori infection after any one of the following 3 tests were positive: culture, histologic study, or any 2 of rapid urease test (CLO test), carbon 13-labeled urea breath test (UBT), and serologic examination. Fresh blood or blood-containing material in the gastric antrum was noted by panendoscopy in 22 patients (group A). In the remaining 55 cases there was no blood in the antrum (group B). RESULTS: The sensitivities of the CLO test, bacterial culture, histologic study, 13C-labeled UBT, and immunoglobulin G serologic test were 45.5%, 36.4%, 77.2%, 95.4%, and 100% in group A, respectively, and 70.9%, 40.0%, 70.9%, 92.7%, and 96.4%, respectively, in group B. There was a statistically significant difference between the sensitivities found for CLO test and 13C-labeled UBT (p < 0.05). Of these 5 tests, only the sensitivity of the CLO test showed a statistically significant difference between groups A and B (p < 0.05). A delayed positive CLO test result was recorded in 13 patients (3 in group A, 10 in group B). CONCLUSION: Noninvasive tests seemed to be more sensitive than invasive tests in detecting H pylori infection in patients with bleeding peptic ulcers. Blood in the antrum might reduce the sensitivity of the CLO test but have no effect on the other tests. The CLO test should be observed for more than 24 hours because of the possibility of a delayed positive result in some patients with bleeding peptic ulcers.

Adult↗
PubMed1999

Evidence against a role for endotoxin in the hyperdynamic circulation of rats with prehepatic portal hypertension.

BACKGROUND/AIMS: Excessive formation of nitric oxide may mediate the generalized vasorelaxation and hyporesponsiveness to vasoconstrictors observed in portal hypertensive states. Endotoxin, released from the bowel and detoxified by the liver, could stimulate inducible nitric oxide synthase directly or indirectly via the cytokine cascade. This study investigated the effect of chronic intraperitoneal injection of polymyxin B, a neutralizing antagonist of endotoxin, on the hemodynamics of partially portal vein-ligated (PVL) rats. METHODS: Concomitantly with endotoxin (600 EU) and dactinomycin (80 microg), polymyxin B (0.1 mg) or normal saline (N/S) was administered via an intraperitoneal route to male Sprague-Dawley rats. Twenty-four hours later, mean arterial pressure was determined. In PVL rats polymyxin B (0.1 mg in 5 cc N/S) or N/S was given intraperitoneally twice daily from 2 days prior to operation until 5 days (short-term) or 14 days (long-term) after the operation. Long-term polymyxin B- or N/S-treated sham-operated rats were included as controls. Hemodynamic studies with a thermodilution technique were performed at the end of treatment. Blood samples were collected from another series of PVL rats with long-term treatment to determine plasma levels of endotoxin and tumor necrosis factor-alpha. Plasma levels of endotoxin and tumor necrosis factor-alpha were measured by Limulus assay and the ELISA method, respectively. RESULTS: With the dosage of 0.1 mg polymyxin B, hypotension in rats subjected to endotoxin and dactinomycin administration could be corrected (polymyxin B vs. placebo: 130.0+/-7.7 vs. 108.8+/-6.7 mm Hg, p<0.05). However, long-term or short-term treatment with the same dosage of polymyxin B failed to ameliorate the hyperdynamic circulation of PVL rats. In addition, long-term treatment with polymyxin B did not change systemic and portal hemodynamics in sham-operated rats. Plasma levels of endotoxin and tumor necrosis factor-alpha were comparable in PVL rats treated with long-term polymyxin B or N/S (p>0.05). CONCLUSIONS: Our findings do not support the role of endotoxin in the hyperdynamic circulation of PVL rats.

Animals↗
PubMed1999

Methacholine-induced fall in forced vital capacity as a marker of asthma severity.

The dose of methacholine causing a 20% fall in forced expiratory volume in 1 sec (FEV1) from baseline (PD20) has been used as an index of asthma severity. The aim of this study was to determine if the percentage fall in forced vital capacity (FVC) from baseline at the PD20 (dFVC%) is an independent marker of asthma severity. We first retrospectively studied the dFVC% and PD20 obtained from 149 consecutive newly diagnosed asthmatics with a positive methacholine-challenge test (MCT). We then performed MCT on 20 normal subjects and 35 stable asthmatics. The 'milder' asthmatics (n = 20) and 'more severe' asthmatics (n = 15) were on regular inhaled corticosteroids: 200 micrograms or less and 800 micrograms or more daily, respectively. A dosimeter technique was used, and normal subjects were given a cumulative dose of 2400 micrograms. The PD20 and dFVC% were calculated using log-linear interpolation of the last two points. Student's unpaired t-tests and linear regression analyses were used for comparison and correlation of results. There was no significant correlation between dFVC% and PD20 among the 149 newly diagnosed asthmatics (r = 0.1), or among the 35 known stable asthmatics (r = 0.008). The more severe asthmatics had a larger dFVC% compared with the milder asthmatics (15.8% vs. 9.6%; P = 0.0005). In addition, inhaled corticosteroid usage correlated better with dFVC% (r = 0.56) than with PD20 (r = 0.36). The normal subjects had a mean fall in FVC of only 4.8%. The percentage fall in FVC at PD20 (dFVC%) may be a useful index of asthma severity which is independent of PD20. This index is potentially complementary to the PD20 in the assessment of asthma severity.

Adrenal Cortex Hormones↗
PubMed1999

The effects of phosphodiesterase type 4 inhibitors on tumour necrosis factor-alpha and leukotriene B4 in a novel human whole blood assay.

1. The aim of this study was to assess the inhibitory activities of phosphodiesterase type 4 (PDE4) inhibitors on tumour necrosis factor-alpha (TNF-alpha) and leukotriene B4 (LTB4) production in a novel human whole blood assay. 2. Lipopolysaccharide (LPS) stimulation of human whole blood caused a time dependent increase in TNF-alpha and prostaglandin E2 (PGE2) plasma levels. Inhibition of LPS-induced TNF-alpha by the selective PDE4 inhibitor RP73401 was proportionally enhanced with endogenous PGE2 (maximal after 24 h). In contrast, blocking endogenous PGE2 production with indomethacin in blood stimulated with LPS for 24 h decreased the potency of RP73401 to that observed with a 4 h LPS incubation. 3. Non-selective and selective PDE4 inhibitors showed greater inhibition of LPS-induced TNF-alpha after 24 h compared to 4 h. Stereoselectivity was only achieved in the 24 h method. 4. LPS-stimulation of whole blood for either 30 min or 24 h followed by N-formyl-Met-Leu-Phe (fMLP) activation resulted in low plasma LTB4 levels. Combination of both treatments resulted in a greater than 7 fold increase in plasma LTB4 levels. Inhibition of the double LPS and fMLP-activated LTB4 production was observed with non-selective and PDE4-selective inhibitors. Their LTB4 inhibitory potencies were similar to that observed in the 24 h LPS-induced TNF-alpha assay. Thus, stimulation of human whole blood with two LPS stimulations followed by fMLP gives rise to both TNF-alpha and LTB4 and their inhibition by various compounds can be assessed in the same blood sample. 5. Calcium ionophore (A23187) stimulation of whole blood resulted in plasma LTB4 levels similar to the double LPS and fMLP method. Inhibition of A23187-induced LTB4 biosynthesis was also achieved by PDE4-selective inhibitors as well as the direct 5-lipoxygenase (5-LO) inhibitor L-739,010. 6. These results confirm the anti-inflammatory properties of PDE4 inhibitors. Thus, this novel human whole blood can be used to assess the biochemical efficacy of PDE4 inhibitors in human subjects.

Calcimycin↗
PubMed1999

Distribution and regulation of cyclooxygenase-2 in carrageenan-induced inflammation.

1 We characterized the regulation of cyclooxygenase-2 (COX-2) at the mRNA, protein and mediator level in two rat models of acute inflammation, carrageenan-induced paw oedema and mechanical hyperalgesia. 2 Carrageenan was injected in the hind paw of rat at low (paw oedema) and high doses (hyperalgesia). COX-2 and prostaglandin E2 (PGE2) levels were measured by RT-PCR and immunological assays. We also determined the distribution of COX-2 by immunohistochemistry. 3 The injection of carrageenan produced a significant and parallel induction of both COX-2 and PGE2. This induction was significantly higher in hyperalgesia than in paw oedema. This was probably due to the 9 fold higher concentration of carrageenan used to provoke hyperalgesia. 4 Immunohistochemical examination showed COX-2 immunoreactivity in the epidermis, skeletal muscle and inflammatory cells of rats experiencing hyperalgesia. In paw oedema however, only the epidermis showed positive COX-2 immunoreactivity. 5 Pretreatment with indomethacin completely abolished the induction of COX-2 in paw oedema but not in hyperalgesia. 6 These results suggest that multiple mechanisms regulate COX-2 induction especially in the more severe model. In carrageenan-induced paw oedema, prostanoid production have been linked through the expression of the COX-2 gene which suggest the presence of a positive feedback loop mechanism.

Animals↗
PubMed1999

Case report: portal vein thrombosis associated with hereditary protein C deficiency: a report of two cases.

Protein C deficiency is one of the causes of curable or preventable portal vein thrombosis. We report two patients of portal vein thrombosis associated with hereditary protein C deficiency. The first patient presented with continuous right upper quadrant pain and high fever. The abdominal sonography revealed normal liver parenchyma but portal vein and superior mesenteric vein thrombosis. Based on a 55% (normal 70-140%) plasma protein C level, he was diagnosed as having protein C deficiency. A trace of his family history showed that his elder brother also had protein C deficiency with a 50% plasma C level. Both patients received anticoagulant therapy. The younger brother showed good response. Unfortunately, the elder one suffered from recurrent episodes of variceal bleeding and received a life-saving splenectomy and devascularization. We herein remind clinicians that early screening and therapy are helpful in preventing late complications of protein C deficiency with portal vein thrombosis.

Abdomen, Acute↗
PubMed1999

The aging effect on corneal curvature and the validity of Javal's rule in Hong Kong Chinese.

PURPOSE: The current study compared the central corneal curvature and the refractive error of Hong Kong Chinese to study the validity of Javal's rule. METHODS: Subjects without corneal pathology were recruited at different age ranges. Their refractive error and the corneal curvature were measured and compared for the right eye only. Two instruments were used for the measurement of corneal curvature including a conventional Bausch & Lomb (B&L) keratometer and a computer-assisted videokeratoscope (TMS-1). RESULTS: Subjects age ranged from 21 years to 77 years were recruited and were categorized into five groups according to age. The Bausch & Lomb keratometer was found to provide corneal information similar to that from the TMS-1. The corneal astigmatism was found to change from with-the-rule to against-the-rule with advancing age. The spectacle astigmatism followed a similar trend. There was a hyperopic shift in the spherical component of the refractive error with aging as well. A regression equation: Spectacle astigmatism = 0.93 (Corneal astigmatism) + (-0.58D x 90) was found, which is similar to the simplified Javal's rule. There was a shift of 1.03D in hyperopia (spherical equivalent) for each decade. CONCLUSIONS: Both the corneal and spectacle astigmatism demonstrated a shift from with-the-rule to against-the-rule with age. The simplified Javal's rule is more suitable for predicting the spectacle astigmatism from corneal astigmatism in Hong Kong Chinese.

Adult↗
PubMed1999

Spider angiomas in patients with liver cirrhosis: role of alcoholism and impaired liver function.

BACKGROUND: Spider angioma is a common sign in patients with liver cirrhosis, but the pathogenesis is still unclear. Alcohol and hyperestrogenemia are both possible etiologies. This study was designed to investigate the relationship of spider angiomas in patients with liver cirrhosis to alcohol, liver function test results, and plasma levels of sex hormones. METHODS: Eighty-two patients with liver cirrhosis and 18 healthy subjects were enrolled in this study. The number, size, and location of the spider angiomas were recorded for all subjects. Plasma levels of estradiol and testosterone were measured. RESULTS: Cirrhotic patients had significantly higher estradiol/testosterone ratios (26.8 +/- 5.1 x 10(-3) versus 8.8 +/- 2.0 x 10(-3); P = 0.002) than healthy controls. Twenty-seven (33%) of the 82 cirrhotic patients had spider angiomas. Cirrhotic patients with spider angiomas were younger (56 +/- 3 versus 66 +/- 1 years; P = 0.002) and had higher serum bilirubin levels (3.3 +/- 0.6 versus 1.7 +/- 0.2 mg/dl; P = 0.002), longer prothrombin time (16.8 +/- 0.8 versus 14.8 +/- 0.4 sec; P = 0.01), and higher prevalence of alcoholism (41% versus 20%; P = 0.04) than those without. Stepwise logistic regression showed that alcoholism and serum bilirubin level were the only significant and independent predictors associated with the presence of spider angiomas in cirrhotic patients (odds ratio = 3.5; 95% confidence interval = 1.2-10.8; P = 0.03, and odds ratio = 2.8; 95% confidence interval = 1.3-5.7; P = 0.006, respectively). CONCLUSIONS: Alcoholism and impaired liver function are important predictors of the presence of spider angiomas in patients with liver cirrhosis.

Aged↗
PubMed1999

Identification of genomic regions controlling experimental autoimmune uveoretinitis in rats.

The present study attempts to identify specific genetic loci contributing to experimental autoimmune uveoretinitis (EAU) susceptibility in F2 progeny of resistant Fischer (F344/N) and susceptible Lewis (LEW/N) inbred rats. F2 progeny of F344/N x LEW/N inbred rats were immunized with the R16 peptide of interphotoreceptor retinoid-binding protein (IRBP). A genome-wide scan was conducted using 125 simple sequence length polymorphism markers in selected F2 animals that developed severe eye disease or remained unaffected to identify phenotype:genotype co-segregation. The F2 population (n = 1287) demonstrated a wide range of histologically assessed EAU scores (assessed on a scale of 0-4). The disease incidence and severity were not consistent with a simple Mendelian inheritance model. Of the F2 hybrid rats, 60% developed EAU, implying the existence of a potent susceptibility locus with incomplete penetrance associated with the LEW genome or a more complex polygenic model of inheritance. Two genomic regions, on chromosomes 4 and 12, showed strong genetic linkage to the EAU phenotype (P < 0.0016), suggesting the presence of susceptibility loci in these chromosomal regions. In conclusion, we have identified two genomic candidate intervals from D4Arb8 to D4Mit17 on chromosome 4 and from the chromosome end to D12Arb8 on chromosome 12, that appear to influence EAU susceptibility in LEW/F344 rats. Further analysis of these genomic regions may lead to identification of the susceptibility genes and to characterization of their function.

Animals↗
PubMed1999

Autoimmunity to a pathogenic retinal antigen begins as a balanced cytokine response that polarizes towards type 1 in a disease-susceptible and towards type 2 in a disease-resistant genotype.

Susceptible, but not resistant, strains of rodents immunized for induction of experimental autoimmune uveitis (EAU) with the uveitogenic protein interphotoreceptor retinoid-binding protein (IRBP) exhibit a type 1 response at the time of disease expression. Here we investigate the evolution of this response using the prototypic EAU-susceptible and EAU-resistant mouse strains, B10.A and BALB/c. Disease severity and IRBP-specific responses (proliferation, cytokines and antibody isotypes) were evaluated 7, 14 and 21 days after uveitogenic immunization. B10.A mice initially exhibited an IgG1-dominated antibody response, and their lymph node cells produced IL-4 and IL-5 in addition to IFN-gamma. On day 14 and 21, however, the IgG2a isotype became predominant, and the primed lymph node cells produced mainly IFN-gamma and IL-12. B10.A mice developed EAU before day 14. BALB/c mice initially produced IL-12 and IFN-gamma in addition to IL-5, IL-4 and IL-10. At later time points IL-12 and IFN-gamma production diminished, and IL-4, IL-5 and IL-10 increased. An IgG1-dominated antibody response was maintained throughout. BALB/c mice failed to develop EAU even at day 21. Thus, both susceptible and resistant genotypes initially mount a balanced, type 0-like cytokine response to a uveitogenic challenge, that subsequently polarizes towards type 1 in the susceptible strain and towards type 2 in the resistant strain.

Animals↗
PubMed1999

Conjunctival epithelial cells cultured on human amniotic membrane fail to transdifferentiate into corneal epithelial-type cells.

PURPOSE: Previous studies on the use of human amniotic membrane (HAM) in rabbit stem cell deficiency models have found the new epithelium growing over the HAM to express cornea-specific keratins (K3 and K12) in 40% of the cases, suggesting that HAM may have induced conjunctival epithelial cells to transdifferentiate into cornea-type epithelial cells. The current study was performed to determine whether HAM could induce transdifferentiation of conjunctival epithelia] cells when cultured in vitro. METHODS: Conjunctival grafts taken from the fornices of New Zealand white rabbits (6-12 weeks old) were placed over HAMs and lifted to an air-media interface using polypropylene double rings. These cultures were maintained in supplemented hormonal epithelial medium with and without 3T3 feeder cells. Rabbit corneal epithelial cells were cultured similarly using strips of keratolimbal grafts placed over HAM. The cultures were terminated at various times between the 8th and 15th day. The cultured epithelial cells were examined histologically and immunohistochemically using monoclonal antibodies AK-2 (to K12 keratin), AM-3 (to goblet cell mucin), and AE-5 (to K3 keratin). RESULTS: Both conjunctival and corneal epithelial cells cultured on HAMs showed multilayered, differentiated epithelial structures. On immunohistochemical examination, both epithelial cells stained positive for AE-5. None of the cultured conjunctival epithelial cells stained positively for AK-2, while the corneal epithelial cells showed positive staining with AK-2. There were no AM-3-positive goblet cells in either epithelial cell culture. There was no difference in the immunohistochemical patterns between cultures with or without 3T3 feeder cells. However, culture without feeder cells seemed to manifest a more degenerative appearance than those with feeders. CONCLUSION: HAM does not induce transdifferentiation of conjunctival epithelial cells into corneal-type epithelial cells under the in vitro culture conditions used in this study.

3T3 Cells↗