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Biomedical subjects

J B Lee

Publications and source records attributed to J B Lee.

At least 91 records · Page 5Linked to original sources
PubMed1998

A simple method for the removal of epithelium grown beneath the hinge after LASIK.

The purpose of this study is to demonstrate a method of how to remove epithelium grown beneath the hinge area after laser in situ keratomileusis (LASIK) without affecting the refractive part of the lenticule. In three cases, an incision was made at the base of the hinge by RK diamond knife to free the lenticule from the stroma. The lenticule was lifted from the nasal edge. The epithelium grown along the interface beneath the hinge area was removed with a Bard-Parker No. 15 knife. The lenticular flap was repositioned with interrupted sutures using 10-0 nylon. No further epithelial ingrowth was observed. The central cornea remained clear leaving a peripheral ring-shaped opacity without affecting the preoperative naked visual acuity. In conclusion, epithelial ingrowth along the interface after LASIK can be removed safely without affecting the refractive part by the incision of the hinge area with a RK diamond knife, removal of the epithelium, and suturing of the lenticule to the stromal bed.

Adult↗
PubMed1998

Comparison of corneal centering in photorefractive keratectomy.

The present study compares three centering methods for excimer laser photorefractive keratectomy (PRK. VISX 20/20) by analyzing the corneal topography. The subjects were grouped according to three different centering methods used in the procedure: an ablation using a light reflex from the patient's cornea pursued by both eyes of the surgeon (Group 1, n = 49); an ablation using a red light reflex from the patient's cornea pursued by the surgeon's left eye only while the right eye remained closed (Group 2, n = 27); an ablation using the patient's center of the pupil pursued by the surgeon's left eye only while the right eye remained closed (Group 3, n = 21). The mean distance from the center of ablation zone to the center of the pupil were; 0.69 +/- 0.45 mm for Group 1, 1.05 +/- 0.48 mm for Group 2 and 0.63 +/- 0.28 mm for Group 3. The degree of deviation in Group 2 was significantly greater than in Group 1 or Group 3. The deviation was greater in the right eyes than the left eyes in Group 2 only. The decentration of the right eye in Group 2 was due to angle Kappa with misalignment of the fixation light and viewing tube containing reticule.

Adult↗
PubMed1998

The effects of diffusion blur on Snellen and grating acuity and foveal function in amblyopia.

In order to verify that the effects of diffusion blur on Snellen and grating acuity in amblyopic eyes resemble those obtained from the peripheral or central retina in normal controls, we conducted the following experiment using a liquid crystal window (Edmund Scientific Co.) to produce diffusion blur on Snellen and grating acuity. Spatial frequencies used for a Snellen chart and Teller acuity card were 3.2, 6.5, 13.0, 26.0 cyc/cm at a working distance of 55 cm. The values of diffusive blur on central and peripheral visual acuity obtained from 20 normal healthy control eyes were compared with those values of central visual acuity in 26 amblyopic eyes. The diffusion blur had a strong negative effect on both Snellen and grating acuity in amblyopic eyes, but it had more potent effects on grating acuity (p < 0.05). The diffusion blur values obtained from the central amblyopic retina were more compatible with those of the central retina than with those of the peripheral retina in the control group (p > 0.05). Snellen acuity obtained from diffusion blur overestimated grating acuity in the normal central acuity group and amblyopic central acuity group. The result of this investigation demonstrated that the liquid crystal diffusion blur had a strong negative effect on both Snellen and grating acuity and suggested that the visual function of an amblyopic retina resembled that of a normal central retina.

Adult↗
PubMed1997

Cloning of a cysteine proteinase cDNA of adult Paragonimus westermani by polymerase chain reaction.

Cysteine proteinase cDNA fragment from adult mammalian trematode, Paragonimus westermani was amplified by reverse transcription-polymerase chain reaction (RT-PCR) using degenerate oligonucleotide primers derived from conserved cysteine proteinase sequences. The 5' and the 3' regions of the cysteine proteinase gene were amplified using the PCR protocol for the rapid amplification of cDNA ends (RACE). It has an open reading frame of 804 bp. The deduced amino acid sequence consists of 268 amino acids. Sequence analysis and alignment showed significant sequence similarity to other eukaryotic cysteine proteinases and conservation of the cysteine, histidine, and asparagine residues that form the catalytic triad. The cysteine proteinase cDNA fragment was also subcloned in the expression vector pET and expressed as a C-terminal His-tag fusion protein in Escherichia coli.

Amino Acid Sequence↗
PubMed1997

Sequence variation of mitochondrial DNA control region in Koreans.

The sequencing data for two mtDNA segments in control region I and II, 385 and 341 nucleotides long, respectively, for 306 unrelated Koreans are presented. In regions I and II, 139 and 58 polymorphic sites, respectively, were noted. These were distributed evenly along the control region, though the frequency of each site was variable. Nucleotide substitution rather than insertion/deletion was the prevalent pattern of variation. A total of 265 different mtDNA lineages in region I and 154 in region II were revealed. This result represents a substantial level of polymorphism in a defined population, and presents the possibility that mtDNA polymorphism could be used as an individual identification marker, especially when nuclear DNA is not available. In view of the complex pattern of variation, meticulous test-sequencing is thought to be more appropriate than RFLP analysis using restriction endonuclease or hybridization using an SSO probe. Racial differences with genealogical usage are also described.

Base Sequence↗
PubMed1997

Analysis of the STR myelin basic protein locus in Koreans.

Allele und genotype frequencies and the mutation rate of a short tandem repeat locus, the myelin basic protein (MBP) gene, were studied in 973 unrelated Koreans. The alleles were distributed in two discrete regions, one in a high molecular weight region (A) above 190 bp and the other in a low molecular weight region (B) below 150 bp. In a heterozygote, two alleles were found in each region. In region A 13 alleles were found and in region B 7 alleles. Most alleles showed a difference of 4 bp, but three interalleles were found in region A. Allele frequencies in Koreans differed from those reported for Germans and Portuguese. Sets of alleles, one from each region, were linked and transmitted to the offspring. A total of 36 haplotypes and 148 genotypes was identified. In 763 gametes of 550 families, whose parent-child relationship was confirmed using other serological and DNA systems, all alleles were transmitted in a Mendelian fashion, and no mutations were observed. The polymorphism information content (PIC) in Koreans was calculated as 0.833 for region A and 0.718 for region B. The power of discrimination (PD) was 0.959 for region A and 0.901 for region B. No significant deviation from Hardy-Weinberg equilibrium could be observed for this system.

Alleles↗
PubMed1997

Loss of heterozygosity at chromosome segment Xq25-26.1 in advanced human ovarian carcinomas.

To determine whether a tumor suppressor gene of importance to epithelial ovarian cancer resides on the X chromosome, we examined loss of heterozygosity (LOH) in 123 epithelial ovarian cancer cases. In 54 such cases, we examined LOH at 26 loci on the human X chromosome. In eight cases, we examined LOH in 14 loci and in 61 cases we examined LOH in 13 loci. Matched DNA samples from tumors and corresponding normal tissues were analyzed by polymerase chain reaction (PCR) amplification of microsatellite markers. Frequent losses were found in epithelial carcinomas at the Xq25-26.l region, including DXS1206 (34.5% loss in informative cases), DXS1047 (27.7%), HPRT (24.1%), and DXS1062 (33.3%). The minimum overlapping region of LOH was approximately 5 megabases (Mb), flanked by DXS1206 (Xq25) and HPRT (Xq26.1). The methylation status of the remaining allele of the androgen receptor gene in the tumors exhibiting LOH at the Xq25-26.1 region suggested that the loss was exclusively in the inactive X chromosome. We next determined whether a significant relationship exists between Xq LOH and other parameters, including histologic grade and/or clinical stage of the tumors and LOH at TP53. The Xq LOH had a significant association with grade 2 to 3 tumors at stages II to IV. Sixteen of 18 cases that showed Xq LOH revealed LOH at the TP53 locus, and 45% of tumors exhibiting LOH at TP53 showed Xq LOH. These results suggest that there may be a tumor suppressor gene or genes which escape inactivation of the X chromosome at Xq25-26.1, and that the loss of the gene(s) at Xq25-26.1 is frequently accompanied by loss of the TP53 or loss of another gene on chromosome 17. These losses may contribute to the progression from a well-differentiated to a more poorly differentiated state or to metastatic aggressiveness.

Carcinoma↗
PubMed1996

Allele frequency and its forensic application of STR Y27 in Korean males.

The allele frequency and mutation rate in a Short Tandem Repeat locus, Y27 were studied in 247 unrelated Korean males using polymerase chain reaction followed by high-resolution polyacrylamide gel electrophoresis, a procedure called the amplification fragment length polymorphism technique. Six alleles were noted ranging from 190 bp to 210 bp. They existed as discrete bands with 4 bp discrepancy. Among which DY3(198 bp), DY4(202 bp) were common with the frequencies of 0.408, 0.356 respectively. Other alleles, DY1(190 bp, frequency 0.020), DY2(194 bp, frequency 0.121), DY5(206 bp, frequency 0.089), DY6(210 bp, frequency 0.004) were relatively uncommon. In a 78 subject father-son study with parenthood confirmed through other genetic studies, no case of mutation was noted. As the allele number was not as large as 6 and two alleles were dominant, the discrimination power in routine individual identification was thought to be low. But in selective cases such as father-son determination or sex determination, this locus could be a valuable genetic marker and we thought these results to be common for the Korean population. These results were also compared with that of other race.

Alleles↗
PubMed1995

Influence of examiner experience and gender on interrater reliability of KT-1000 arthrometer measurements.

BACKGROUND AND PURPOSE: Measurements of the integrity of knee ligaments are used to diagnose injuries as well as to document the state of recovery. Many factors, such as gender and experience of the examiner, are capable of influencing the reliability of such measurements. The purpose of this study was to determine the effects on interrater reliability of measurements obtained using the KT-1000 arthrometer of experience, gender, and leg tested. SUBJECTS: Two experienced examiners (1 male, 1 female) and two inexperienced examiners (1 male, 1 female) tested 22 subjects with unilateral anterior cruciate ligament (ACL) pathology. METHODS: The leg with an ACL injury and the uninjured leg of each subject were evaluated by all four examiners within one test session using 67-N, 89-N, maximum manual, and active anterior drawer tests. RESULTS: Greater anterior displacement values were found in the legs with ACL injury than in the uninjured legs. Reliability estimates, as assessed by intraclass correlation coefficients (2,k) and measurement error (SEM), suggest that therapist experience may be a more important factor influencing reliability than gender. CONCLUSION AND DISCUSSION: Given the magnitude of the errors obtained for tests routinely conducted in the clinic using the KT-1000 arthrometer, we recommend that repeated measurements should be taken by the same examiners whenever possible. [Ballantyne BT, French AK, Heimsoth SL, et al. Influence of examiner experience and gender on interrater reliability of KT-1000 arthrometer measurements.

Adolescent↗
PubMed1995

Seroreversion of the serological tests for syphilis in the newborns born to treated syphilitic mothers.

BACKGROUND: IgG antibodies from mothers adequately treated for syphilis can cross the placenta and appear in the sera of healthy newborns without infection. In such infants, a false diagnosis of congenital syphilis is often made. We have designed a retrospective survey to determine the time of seroreversion of the serological tests for syphilis (STS) in uninfected newborns born to mothers who were adequately treated for syphilis. MATERIALS AND METHODS: Fifty two seropositive, untreated newborns born to 51 mothers treated for syphilis were studied. The newborns were followed at 1, 3, 6, 9, and 12 months of age until seroreversion was detected. The VDRL test was followed until 12 months in 12 of the 22 newborns who were positive at birth, the TPHA in 21 of the 46 newborns, and the FTA-ABS test in 22 of the 48 newborns. RESULTS: In the first serological tests done within 1 month after birth, the VDRL was positive in 22 newborns (42%), the TPHA in 46 (88%), and FTA-ABS in 48 (92%). The VDRL seroreverted within 6 months after birth in 84%, and within 1 year in 100%. The TPHA test seroreverted in 95% within 1 year after birth. The FTA-ABS test seroreverted in 100% within 1 year after birth. CONCLUSIONS: In most seropositive, untreated newborns born to treated mothers the VDRL became negative within 6 months after birth and the TPHA and FTA-ABS within 1 year. This result is consistent with current Centers for Disease Control (CDC) guidelines. However, although the CDC guidelines are adequate in general, we think that some revision is desirable concerning the IgM test and combination of the test results in order to rule out congenital syphilis in seropositive, nonsymptomatic newborns born to the treated mothers.

Female↗
PubMed1995

ELISA inhibition test using monoclonal antibody specific for Treponema pallidum as the serologic test for syphilis.

Monoclonal antibodies (Mabs) specific for Treponema pallidum were produced using hybridoma technology. In this study an ELISA inhibition test based on competitive inhibition by antibodies from human test sera of the binding of the enzyme-labelled Mabs to T. pallidum was performed. Inhibition of the seroreactivity of Mabs was decreased according to the dilution of rabbit antiserum to T. pallidum. Seropositivity was found in 100% of secondary and early latent syphilis patients, 75% of primary syphilis patients, and 80% of late latent syphilis patients. The mean percentage inhibition was significantly higher in each syphilis group than in the controls, and statistically significant differences were shown between all the syphilis groups. VDRL and TPHA titers were correlated with the percentage inhibitions. Therefore the ELISA inhibition test using Mab specific for T. pallidum might well be a suitable tool as a new serologic test for syphilis.

Analysis of Variance↗
PubMed1995

Detection of 17p loss in gastric carcinoma using polymerase chain reaction.

BACKGROUND: The loss of heterozygosity (LOH) of 17p has been previously studied with conventional Southern blot-restriction fragment length polymorphism analysis, but the relatively low informativity was an obstacle to extensive analysis. To overcome this problem and to investigate the significance of 17p LOH in gastric carcinoma, we employed polymerase chain reaction and subsequent silver staining of DNA. EXPERIMENTAL DESIGN: LOH of p53 gene and D17S5 locus on 17p was analyzed using polymerase reaction; the relationships between 17p LOH and conventional clinicopathologic parameters were evaluated. RESULTS: The LOH of p53 gene and D17S5 was found in 36.5% (23 out of 63) and 63.3% (38 out of 60) informative cases, respectively. There was no significant correlation between LOH of these two loci, whereas the frequency of the D17S5 locus was significantly higher (p < 0.01), which suggested that there may be another putative tumor suppressor gene between the two loci or distal to D17S5. The LOH of p53 gene and D17S5 locus was not significantly associated with abnormal p53 expression, depth of invasion, histologic type of the tumor (Lauren's classification), or the status of lymph node metastasis. CONCLUSIONS: The polymerase chain reaction and silver staining of DNA seemed to be a simple and excellent method for the evaluation of chromosomal allelic loss. The 17p LOH was frequently found in gastric carcinoma, but specific association with conventional clinicopathologic parameters was not found.

Adult↗
PubMed1994

Detection of Treponema pallidum by polymerase chain reaction in the cerebrospinal fluid of syphilis patients.

To find out if polymerase chain reaction could be used as a diagnostic tool for detecting neurosyphilis, we have applied the PCR for the detection of Treponema pallidum DNA in the cerebrospinal fluid (CSF) of syphilis patients. The results of the PCR of the CSF in 26 patients with at various stages of illness were compared with the results of other conventional tests used in the WHO criteria. T. pallidum was detected in the CSF of patients at all stages of syphilis, which indicates that they invade the central nervous system from the early stages of infection. However, the presence of T. pallidum in the CSF was not correlated with the results of other tests used in the WHO criteria, and its significance in the diagnosis of neurosyphilis should further be evaluated.

Cerebrospinal Fluid↗
PubMed1993

Relapsing syphilis.

Although penicillin still remains highly effective for syphilis, concerns have been raised that current regimens may be inadequate for the treatment of early syphilis. We report the failure of benzathine penicillin in the treatment of secondary syphilis. Extensive tracing of sexual contact history failed to identify sources of possible reinfection; therefore, we believe that this case represents a treatment failure and an ensuing relapse of secondary syphilis.

Adult↗
PubMed1993

A strong association between thyrotropin receptor-blocking antibody-positive atrophic autoimmune thyroiditis and HLA-DR8 and HLA-DQB1*0302 in Koreans.

We investigated whether the associations between HLA alleles of patients with autoimmune hypothyroidism varied according to the presence or absence of TSH receptor-blocking antibody (TRBab). We analyzed the HLA-A, -B, -C, and -DR antigens by serotyping and the DQA1 and DQB1 genes using both enzymatic DNA amplification and sequence-specific oligonucleotide hybridizations. The patient population consisted of 47 Korean patients with atrophic autoimmune thyroiditis and 62 patients with goitrous autoimmune thyroiditis. The antigen frequency of HLA-DR8 was significantly increased in 23 atrophic autoimmune thyroiditis patients that were positive for TSH binding inhibitor immunoglobulin (TBII) compared to 136 controls [52% vs. 16%; chi 2 = 13.1; Pc (corrected P value) = 0.003]. This relative risk was 5.7; the etiological fraction was 0.43. HLA-DQB1*0302 was also increased in patients with TBII-positive atrophic autoimmune thyroiditis (24% vs. 7%; chi 2 = 11.2; Pc = 0.012; relative risk = 4.4; etiological fraction = 0.19). No specific DR antigens or DQB1 alleles were increased in either TBII-negative atrophic autoimmune thyroiditis or goitrous autoimmune thyroiditis. A significant decrease in the frequency of HLA-DR6 antigen was observed in both TBII-positive atrophic autoimmune thyroiditis (0% vs. 32%; chi 2 = 8.4; Pc = 0.03) and goitrous autoimmune thyroiditis (0% vs. 32%; chi 2 = 23.2; Pc < 0.001) patients. The frequency of the HLA-Cw1 antigen was significantly increased in all patient groups. We conclude that TRBab-positive atrophic autoimmune thyroiditis is immunogenetically different from both goitrous autoimmune thyroiditis and TRBab-negative atrophic autoimmune thyroiditis. It is possible that HLA-DR8 and/or DQB1*0302 may be related to the susceptibility genes involved in the production of TRBab in Koreans.

Adult↗