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Biomedical subjects

Y Hui

Publications and source records attributed to Y Hui.

At least 55 records · Page 3Linked to original sources
PubMed2000

Effect of the external nasal dilator on nasal minimal cross-sectional area in orientals as assessed by acoustic rhinometry.

OBJECTIVE: This study aimed to evaluate the effect of the external nasal dilator on the dimension of the nasal valve in Orientals. DESIGN: A cohort study of normal subjects. SETTING: Academic institution. METHODS: The nasal fossae of normal subjects were assessed by acoustic rhinometry before and after application of the external nasal dilator. MAIN OUTCOME MEASURES: The minimal cross-sectional area of the nasal fossae and the total cross-sectional area of the nose. RESULTS: Nasal fossae of 25 normal subjects were evaluated. There was a significant increase of 0.10 cm2 (SD = 0.16) or a 17% increase in the minimal cross-sectional area of the 50 nasal cavities after application of the external nasal dilator (Wilcoxon's matched-pairs signed rank test, p = .0001). A significant increase in the total minimal cross-sectional area for the whole nose after application was also present (0.19 cm2, SD = .27, or 16%; Wilcoxon's matched-pairs signed rank test, p = .0032). CONCLUSIONS: The external nasal dilator results in an increase in the minimal cross-sectional area of the nasal airway in Orientals.

Cohort Studies↗
PubMed2000

[Melanoma antigen-3 expression in human hepatocellular carcinoma].

OBJECTIVE: To investigate the expression of melanoma antigen-3 (MAGE-3) mRNA in human hepatocellular carcinoma (HCC) and probe into the theoretical feasibility that MAGE-3 antigens can be developed as a new peptide vaccine for immunotherapy in HCC patients. METHODS: The expression of MAGE-3 mRNA in HCC tissues and the adjacent non-HCC liver tissues was studied using RT-PCR in 45 HCC patients. The results were compared with those of 16 cirrhotic patients and 12 patients whose liver tissues were pathologically normal. MAGE-3 mRNA positive PCR products were DNA sequenced in 3 HCC patients. The sequenced fragments of MAGE-3 cDNA were used as template by which a [alpha(32)P] labeled probe was synthesized and employed for Southern blot analysis. HLA class I-A and -B typing of 43 HCC patients were assayed by ELISA. RESULTS: Of the 45 HCC samples, 35 (78%) expressed MAGE-3 mRNA and six HCC adjacent tissues were also positive in MAGE-3 expression. Pathological examination showed cellular heteromorphism in these adjacent tissues. The non-HCC liver tissues from cirrhosis and normal liver samples were not MAGE-3 mRNA detectable. The DNA sequence confirmed that the target gene fragment in all of the 3 samples of PCR products was MAGE-3 cDNA. Southern blotting result confirmed that of RT-PCR assay. In HCC patients, the predominant types of HLA were A(2) (53.5%), A(11) (25.6%), A(24) (20.9%), A(33) (20.9%), B(13) (28.3%), and B(35) (23.2%). MAGE-3 mRNA expression in HCC showed no correlation with the level of serum AFP and the size of the tumor. CONCLUSIONS: MAGE-3 mRNA is expressed at a high percentage of HCC samples. This tumor rejection antigen may be used as peptide vaccine for immunotherapy of HCC patients. The phenomena that some non-HCC adjacent tissues with heteromorphism can express MAGE-3 like their paired HCC tissues indicate that the expression of MAGE-3 may be an indicator in the early stage of carcinogenesis of liver tissues.

Aged↗
PubMed2000

[The nuclear hardness and associated factors of age-related cataract].

OBJECTIVE: To determine the nuclear hardness and associated factors of age-related cataract. METHODS: Forty-seven eyes of 47 patients with age-related cataract aged > 50 years were studied. The opacity of lenses was assessed and classified by the LOCS II pre-operatively. The lens nucleus obtained during extracapsular cataract extraction (ECCE) was measured. By means of a fine conical probe and dynamometer, the resistance to penetration of different lens layers was transferred to an electric signal and recorded by a function recorder. The hardness to the penetration of different lens layers was calculated. Multivariate regression analysis was applied to the parameters including age, color of the nucleus, duration of symptoms and other factors. RESULTS: The mean force required to penetrate the lens was (0.51 +/- 0.29) Newtons (N) for grade I, (1.41 +/- 0.35) N for grade II and (1.95 +/- 0.42) N for grade III; it increased to (2.96 +/- 0.62) N for grade IV. The hardest part of the lens was located at the nucleus center. Multivariate analysis of the data showed that 85% of the variation in hardness could be explained in terms of color and opacity. The patients with myopia and diabetics had an increased incidence of grading IV nuclear sclerosis. Regression analysis revealed a positive correlation between nucleus color and weight (r = 0.4565), diameter (r = 0.5263), thickness (r = 0.5552) and hardness (r = 0.8969), P < 0.001. There was a weak positive correlation between age and the weight of nucleus (r = 0.3239, P < 0.05). CONCLUSIONS: The results indicate that the color can be used more reliably to predict physical characteristics of lens nucleus, the preoperative knowledge of which would help the surgeon in planning small-incision surgery including phacoemulsification.

Age Factors↗
PubMed2000

Retrograde labeling of adult rat retinal ganglion cells with the flurogold.

PURPOSE: To study the densities and distribution of retinal ganglion cells(RGC) in adult rat retinae with flurogold(FG) labeling retogradely. METHODS: FG was injected to the superior colliculi(SC) and dorsal lateral geniculate nuclei (dLGN) in adult rats and the retinae were examined by fluorescence microscopy at various periods of time. RESULTS: FG-labelled RGC were observed in the retina as early as 3 days after application of FG. The labelled cells gradually increased in density, reached 95% of the maximal number on days 7 and the maximal number on days 30. The density of labelled cells was higher in the posterior pole than in the peripheral area. The fluorescence intensity in labelled cells maintained up to 60 days. CONCLUSION: The FG retrograde labeling method is reliable and effective for quantity of RGC.

Animals↗
PubMed2000

[Protective effects of brain-derived neurotrophic factor on injured retinal ganglion cells of rats].

PURPOSE: To investigate in vivo the survival of retinal ganglion cells(RGC) after optic nerve crush with intraocular injection of Brain-derived neurotrophic factor (BDNF). METHODS: Sprague-Dawly(SD) rats were divided into normal control, crush control, medium treatment and BDNF treatment group, and every group had 20 eyes. RGC of adult rats were labeled with fluorogold. Seven days later, the optic nerve was intraorbitally crushed and BDNF was injected into the vitreous. Five, 7, 14, 21 and 28 days after crush, the numbers of RGC were counted. RESULTS: The densities of RGC began to decrease 7 days after injury, the number of RGC was 70.2% and 40.5% of normal controls on days 14 and 28, respectively. In the group with BDNF injection, RGC densities decreased on days 7, but RGC densities were much higher than that of controls on 7, 14, 21, and 28 days after injury (P < 0.01). CONCLUSION: BDNF administered intraocularly at the time of crush can protect RGC from injury and cell death.

Animals↗
PubMed2000

[Ocular axial length and refractive changes in pediatric pseudophakia].

PURPOSE: To evaluate the ocular axial length and refractive changes that occured in children who had cataract extraction with intraocular lens implantation and to investigate the factors that influenced the pseudophakic refraction. METHODS: A review of 12 eyes in 10 children (mean age 7.16 years, range 3.83 to 10.16 years) who had cataract extraction with intraocular lens implantation was undertaken. Patients were followed for an average of 35.8 months. The preoperative and the last postoperative axial length and corneal curvature (K readings) in both operated and unoperated eyes were measured. The distance from the vertex of the cornea to the anterior vertex of intraocular lens (AVpc) was measured in the final follw-up. The initial (in two weeks) and the last refractive status of pseudophakia were examined. Overall age at surgery averaged 7.16 years (range 3.83 to 10.16 years), with followed up of 35.8 months. RESULTS: In the 12 operated eyes, the mean axial growth was 0.39 mm, whereas in the other eight unoperated eyes it was 0.66 mm. Though the axial length of both eyes increased significantly after surgery (P < 0.05), there was no significant difference in the postoperative increase of axial length between the two groups(P > 0.05). In K readings, there was no significant difference between the operated and unoperated eyes before surgery and in the last follow-up respectively. There was no significant difference between the preoperation and the last follow-up in the operated and the unoperated eyes respectively. The average calculated AVpc (AVpc2) was 4.66 30 mm, but the average objective AVpc (AVpc1) measured with ultrasonic biometry was 3.83 mm. The average difference between them was 0.8320 mm and was significant (P < 0.01). According to SRK formula, using preoperative and the last postoperative axial length and corneal curvature to predict refractive changes, the myopic shift was -1.53 D, but the average objective refractive difference between the last and initial examination after surgery was -3.86 D. The average difference between the predicted and actual postoperative refractive changes was significant (P < 0.05). CONCLUSION: Our study suggests that there may be no effect on ocular growth in children (3 to 10 years) followed cataract extraction and intraocular lens implantation. Increasing of axial length and moving forward of intraocular lens induced by complication may result in myopic shift in pseudophakia of children. Slightly undercorrected eyes with intraocular lens in children after cataract extraction will gradually move to emmetropia or moderate myopia in adulthood.

Adolescent↗
PubMed2000

[The recent progress on the role of alpha-crystallin as a molecular chaperone in cataractogenesis].

The alpha-crystallin is a major structural protein within the lens and consists of two types of subunit, alpha A and alpha B. These subunits propose a model for the quaternary structure of alpha-crystallin. It has been known for many years that its main function is to serve as a structural and refractive elements in lens. Until 1992, Horwitz suggested that alpha-crystallin could act in a chaperone-like manner. Many studies have showed that alpha-crystallin can protect enzymes and other crystallins against both chemically- and thermally-induced inactivation or aggregation, which may play an important role in maintaining transparency of lens. A polypeptide sequence of alpha A-crystallin or extension of alpha B-crystallin in C-terminal-region and hydrophobic N-terminal-region are all essential for chaperone function. A decrease in chaperone activity from nuclear crystallin has been showed in age-dependent fashion. Post-translational modifications occurring to alpha-crystallin with increasing age and during cataract formation may decrease the chaperone activity of alpha-crystallin to different extent, resulting in an increase in other crystallins aggregation and enzymes inactivation. Therefore, these aggregates will increase scattering of light and lead to lens opacification. Development of protective agents for molecular chaperone activity of alpha-crystallin, in conjunction with knowledge of decreasing post-translational modifications, could potentially lead to a new field for the research on pathogenesis and clinical treatment of cataract.

Animals↗
PubMed2000

[Vitrectomy combined with intraocular lens implantation for 103 selected cases of complicated ocular trauma].

PURPOSE: To observe the visual outcome of vitrectomy combined with intraocular lens (IOL) implantation in one operation for patients with complicated ocular trauma. METHODS: Clinical records were retrospectively reviewed in 103 patients with complicated ocular trauma (104 eyes) who underwent vitrectomy combined with IOL implantation in one operation. RESULTS: The series of cases included 35 patients with intraocular foreign body (IOFB), 37 with penetrating injury, 9 (10 eyes) with explosive injury but without IOFB, and 22 with blunt trauma. Preoperatively, visual acuity was no-light-perception to counting fingers in 88 eyes (87.1%) of 100 patients (101 eyes). Visual acuity improved in 94 eyes (93.1%) including 74 eyes (73.3%) with 0.1-1.5 postoperatively. Retinal detachment occurred in one eye during follow-up and cured with pars plana vitrectomy. CONCLUSION: Vitrectomy combined with IOL implantation in one operation can be a safe, fast and effective approach for visual recovery in selected patients with complicated ocular trauma.

Adolescent↗
PubMed2000

[Morphological changes of cultured rabbit retinal cells after injury].

PURPOSE: To investigate the morphological changes of cultured rabbit retinal cells after injury. METHODS: Mechanical scratch was done in nenatol rabbit retinal cell culture and in Schwann Cell(SC)/retinal cell colculture. The morphological changes of different sorts of cells after the injury were observed under the phase contrast microscope for 24 h. RESULTS: About 30 min after injury, many glial cells moved to the blank region and proliferated to form gliosis. Axons of retinal neurons began to regenerate 6 h post injury. The direction of regrowth was influenced by the environment. In the coculture, regeneration of axons was discerned only 3 h after injury. CONCLUSION: Axons of retinal neurons had strong capability of regeneration; Gliosis was not the absolute obstacle of regeneration; SC played a role in promoting the axon regeneration.

Animals↗
PubMed1999

The reform of the rural cooperative medical system in the People's Republic of China: interim experience in 14 pilot counties.

During the 1960's and 1970's the Chinese government encouraged the 'rural cooperative medical systems' (RCMS), in order to ensure access to basic health care among the rural population. There was a break in the development of the RCMS in the early 1980's, as a consequence of market economic reforms. These reforms involved a shift from a communal to a household production system. As a result the collective way of financing rural health care was more or less abandoned. However, the government of the People's Republic of China was aware of the need to provide social protection against health care expenses. In March 1994 the government initiated a project to reestablish the RCMS. This project was implemented on a pilot basis in 14 counties of seven provinces. The reestablishment of the RCMS would be guided by the basic principles of health insurance. In October 1995, a first mid-term evaluation of the RCMS Project was held. One of the major research questions concerned the extent to which the RCMS had reduced the risk of paying health care bills that would otherwise be a burden on families. This article addresses this question and assesses the results obtained after two years of RCMS experimental work. A general finding is that the population structure by occupation and income varies, and that the RCMS has adapted itself to this variety. It is also confirmed that the burden of health care costs on families was reduced, more so in some counties than in others, but this reduction has been modest. The research results indicate that there is ample room for improvement. The outlook is hopeful, however. At the national level, there is now systematic thinking about RCMS. The current RCMS work is also having a considerable influence on other counties that are keen to reestablish the RCMS.

China↗
PubMed1999

Measurement of nasal geometry by acoustic rhinometry in normal-breathing Asian children.

OBJECTIVE: The purpose of this study was to obtain normal values of nasal geometry in Asian children with no nasal problems using the acoustic rhinometry method. METHOD: Acoustic rhinometric measurement of the nasal fossae was performed in pediatric patients coming for general surgical operations with no nasal problem. RESULTS: A cohort study of 183 children in an acute care hospital with full elective and emergency surgical services was undertaken. The mean minimal cross-sectional area (MCA), which was functionally important for nasal breathing, was found to be 0.32 cm2 (SD = 0.13) and situated at 1.40 cm (SD = 0.26) from the anterior nare. Normal values for area, length, and volume of the nose in these children as a group and at different ages from 1 to 11 years old were obtained. CONCLUSIONS: Acoustic rhinometry was found to be well tolerated by the children. The MCA was confirmed to be situated at the anterior part of the nose and had a positive correlation with an increase in age.

Acoustics↗
PubMed1999

[TNF-alpha, IL-8 and IL-6 in the early inflammatory stage of experimental PVR model induced by macrophages].

OBJECTIVE: To observe the levels of cytokines, tumor necrosis factor-alpha (TNF-alpha), interleukin-8 (IL-8) and IL-6 in the early inflammatory stages of a rabbit proliferative vitreoretinopathy (PVR) model induced by macrophages. METHODS: The vitreous and venous blood of rabbit eyes of the PVR model were obtained and tested with ELISA kits of TNF-alpha, IL-8 and IL-6 and analyzed statistically. RESULTS: The TNF-alpha level increased at the 7th day after macrophage injection and reached its peak (309 pg/ml) on day 21. IL-8 and IL-6 maintained their higher levels during 7 to 21 days after macrophage injection and the peak levels were 1 325 pg/ml and 998 pg/ml on day 14 respectively. Those showed significant differences compared to control (P <or= 0.05). CONCLUSION: The 3 cytokines, TNF-alpha, IL-8 and IL-6, present high levels in the early stage and proliferative phase of the PVR model and decrease to normal level in the regeneration (scarring) phase, indicating that these cytokines may play an important role in initiating and modulating the cellular proliferation.

Animals↗
PubMed1999

Immunocytochemical study of cells in the vitreous of proliferative vitreoretretinopathy.

PURPOSE: To identify the cellular components of vitreous samples obtained during vitrectomy for proliferative vitreoretinopathy (PVR). METHODS: With the use of three intermediate filament (IF) proteins, vimentin, glial fibrillary acidic protein (GFAP), and cytokeratin (CK), cytocentrifuge slides of 14 fresh vitreous aspirates were detected with immunohistochemical technique. RESULTS: All the specimens contained epithelial-like proliferative cells with or without pigment and some membrane-like pieces. Immunocytochemical staining showed that 76.0-90.0% cells stained for CK, 17.4-29.6% cells expressed GFAP, and 80.1-91.0% cells were positive for vimentin. CONCLUSIONS: Majority of cells in the vitreous samples originated from retinal pigment epithelial cells (RPE) and glial cells in PVR. Expression of IF proteins may be determined by tissue of origin and local microenvironment.

Adolescent↗
PubMed1999

[Expression of vimentin in the lenses of vimentin transgenic mice].

PURPOSE: To observe the expression of vimentin in the lenses of vimentin transgenic mice and investigate the role of vimentin in the formation of cataract. METHODS: The 12.7 kb chicken vimentin genes were microinjected into the male pronuclei of ICR mice. The injected embryos were transferred to the pseudopregnant recipient females and then generated several transgenic mice. Twenty mice developed cataract by cross-breeding. Expression of vimentin in 4 cataractous lenses and 4 normal lenses were detected by ABC immunohistochemical method. Usig SDS-PAGE and Western blot technique, we seperated and measured vimentin in the normal and two cataract lenses, in which one was part opacity and the other was complete opacity. RESULTS: Besides in the epithelial cells, vimentin was overexpressed in the cells in anterior cortex and equatorial region in the lenses of transgenic mice. By SDS-PAGE and Western blot, 57 KD urea-soluble protein bands were seperated in normal and cataract lenses and were reacted with vimentin antiserum specifically. In normal lens, partly and completely opaque lenses respectively, the values of average grey density of these bands were 15.56, 34.59 and 33.06 and the percentages of vimentin in urea-soluble fraction were 7.26%, 9.05% and 9.17%, according to the sum of the grey level values of each band. CONCLUSION: Over and ectopic expression of vimentin in the Lenses of transgenic mice inhibits the lens cell differentiation and is linked to cataract formation.

Animals↗
PubMed1999

[A quantitative study of the effect of daunoblastina on argyrophilic nucleolar organiser region-associated proteins in cultured human retinal pigment epithelial cells].

PURPOSE: To investigate the effect of daunoblastina on argyrophilic nucleolar organiser region-associated proteins (AgNORs) in cultured human retinal pigment epithelium (RPE) cells. METHODS: The culture medium of secondary cultured human RPE cells were replaced with a daunoblastina-containing one at a dose of 180 micrograms/L, and the cells were incubated for 12 hr at 37 degrees C. After that, the medium was withdrawn, fresh medium was added and incubation was carried out for an additional 24 hr. AgNORs were studied by using a silver staining technique and image analysis system. RESULTS: The area of intranuclear AgNORs (micron 2/nucleus) in the control and the daunoblastina-treated group were 41.61 +/- 4.52 and 13.66 +/- 0.65(P < 0.01), and the area density of intranuclear AgNORs(AgNORs/nucleus area ratio)(%) in the two groups were 20.37 +/- 1.97 and 13.06 +/- 2.44(P < 0.01) respectively. CONCLUSION: Inhibiting nucleolar organiser region transcriptional activity may be partly responsible for the cytotoxicity of daunoblastina on the cultured human RPE cells.

Adult↗