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H Y Lee

Publications and source records attributed to H Y Lee.

At least 19 recordsLinked to original sources
PubMed1992

Identification of bent DNA and ARS fragments in the genome of Choristoneura fumiferana nuclear polyhedrosis virus.

We identified four CfMNPV DNA fragments with autonomously replicating sequences (ARS) functional in Saccharomyces cerevisiae. A 0.9-kb fragment which, mapped to 54.5 to 55.3 map units within EcoRI HI of the CfMNPV genome, showed the strongest ARS activity of the four. Sequence analysis of this 0.9-kb DNA segment revealed an A+T-rich region separated from a G+C-rich region by 320 bp. Although no sequence matched exactly the ARS core-consensus sequence, 13 near-matches differing by only one or two nucleotides from the core-consensus sequence, were identified. Ten near-matches were clustered within a 105-bp A+T-rich region, and were arranged as inverted repeats. A section of bent DNA structure was predicted within this region. The bent DNA, which showed temperature-dependent retardation during polyacrylamide gel electrophoresis, was unique as its sequence was arranged as a symmetrical 'tilde' (approximately) structure. The second (1.0 kb) and third (1.6 kb) ARS-bearing fragments mapped within EcoRI-E and -B fragments which contain homologous repeat sequences. The fourth (1.5 kb) fragment had the weakest ARS activity and mapped to the EcoRI-D or -B regions of the genome.

Baculoviridae↗
PubMed1992

Expression and amplification of cellular oncogenes in human developing placenta and neoplastic trophoblastic tissue.

To confirm the expression of cellular oncogenes during normal development, their differential RNA levels in developing human placenta have been studied using radioactive probes such as v-abl, v-erbA, v-fms, v-mos, v-myc, N-ras and v-src. The c-mos and N-ras genes are expressed and amplified at high levels especially in term placenta, while c-abl, and c-erbA are expressed constantly during development. These findings indicate that c-mos and N-ras genes may be closely linked to normal differentiation, although c-abl and c-erbA may participate in overall developmental processes. In contrast, transcripts of c-myc and c-src are enhanced at first trimester and decreased sequentially thereafter, showing that these genes may play a role in early proliferation. Expression patterns of c-fms gene are same as that of c-myc and c-src except reelevation at term. In addition, to characterize the effect of cellular oncogene expression has been also examined in hydatidiform mole and tumor cells such as BeWo and choriocarcinoma. All cellular oncogenes examined in this study were significantly overexpressed. Thus, our results suggest that cellular oncogene activation may be strongly associated with neoplastic change of trophoblast.

DNA Probes↗
PubMed1992

Generation and analysis of defective genomes of Autographa californica nuclear polyhedrosis virus.

We have generated defective genomes of Autographa californica nuclear polyhedrosis virus (AcNPV) by serial, undiluted passage in IPLB-SF-21 cell culture in an attempt to identify potential cis-acting sequences important for AcNPV DNA replication. Viral DNA isolated from some of the 81 serial passages was analyzed by pulsed-field gel electrophoresis, restriction endonuclease analysis, and Southern blot hybridization. AcNPV-defective genomes appeared to be generated through a series of successively smaller and transiently stable intermediates. Although the defective genomes at passages later than passage 65 (P65) were somewhat heterogeneous in size, those of the majority of the population had a mean size estimated to be 50 kb, or 40% of that of standard virus. Defective genomic DNA at P81 hybridized strongly only to a 2.8-kb region mapping within 85.0 to 87.2 map units of AcNPV DNA (most of HindIII-K and a small part of HindIII-B), suggesting that the majority of P81-defective genomes were missing most of the 128-kb wild-type DNA sequence, except for this small 2.8-kb fragment. Furthermore, our results indicated that the defective genomes of P81 were composed largely of reiterations of this sequence. We suggest that the 2.8-kb DNA segment retained by the defective AcNPV genomes of P81 contains an important cis-acting element(s) sufficient for viral DNA replication in AcNPV-infected cells.

Animals↗
PubMed1992

CNS complications of cocaine abuse: prevalence, pathophysiology, and neuroradiology.

The United States is facing an epidemic of cocaine use by adolescents and young adults from all socioeconomic backgrounds. Epidemiologic data suggest that the use of the drug continues to increase on a year-by-year basis. This is a serious public health problem because cocaine is highly addictive and is associated with a variety of serious complications. In the CNS, these include stroke, intracerebral hemorrhage, vascular spasm, and possibly vasculitis. Seizures and sudden death have been reported. Cocaine use during pregnancy may be associated with fetal hypoxia, intracerebral hemorrhage, and possibly congenital malformations in the neonate. Many of these complications have been recognized only in the last 5-10 years. For example, ischemic changes in the brains of chronic cocaine abusers have been reported only recently. Because even further increases in cocaine use are predicted by drug enforcement officials, it is expected that radiologists will encounter its complications more frequently in the future. Therefore, radiologists should become familiar with the radiologic manifestations of the drug's effects. This article describes the drug's pathophysiology and complications and discusses the evolving role of imaging procedures.

Brain↗
PubMed1992

Variations of the ventral rami of the brachial plexus.

We studied the variations in the ventral rami of 152 brachial plexuses in 77 Korean adults. Brachial plexus were composed mostly of the fifth, sixth, seventh and eighth cervical nerves and the first thoracic nerve (77.0%). In 21.7% of the cases examined, the fourth, fifth, sixth, seventh and eighth cervical and the first thoracic nerves contributed to the plexus. A plexus composed of the fourth, fifth, sixth, seventh and eighth cervical and the first and second thoracic nerves, and a plexus composed of the fifth, sixth, seventh eighth cervical nerves were also observed. The plexuses were classified into three groups according to cephalic limitation, and the plexus of group 2 in which the whole fifth cervical nerve enters the plexus, were observed the most frequent. The average diameter of the sixth and the seventh cervical ventral rami of the plexus was greatest and that of the fifth cervical was smallest. The largest nerve entering the plexus was the sixth or the seventh cervical nerve in about 79% of cases. The dorsal scapular nerve originated from the fifth cervical ventral ramus in 110 cases (75.8%). The long thoracic nerve was formed by joining of roots from the fifth, sixth, and seventh cervical nerves in 76.0% of cases. Also, a branch to the phrenic nerve, the suprascapular nerve, a nerve to the pectoralis major muscle and a nerve to the subscapular muscle arising from the ventral rami of the plexus were observed.

Brachial Plexus↗
PubMed1992

Effect of captopril on heavy proteinuria in patients with various glomerular diseases.

The effect of captopril on proteinuria was evaluated in twenty patients with various glomerular diseases excreting heavy proteinuria (> 3.0 g/day). Captopril in a daily dose of 37.5 mg was administered orally three times a day to all patients and they were followed for eight weeks. Twenty-four hour urinary excretion of protein, creatinine, sodium, selective protein index (SPI), and blood chemistry including serum electrolytes were measured every two weeks. Twenty-four hour urinary protein excretion per gram creatinine started to fall within two weeks of captopril administration and became nearly stable after four weeks of therapy (p < 0.05). Mean 24-hour urinary protein excretion decreased significantly from a pretreatment value of 9.0 +/- 6.0 gm/gm of cr. to 4.4 +/- 3.5 gm/gm of cr. after eight weeks of captopril treatment. The serum albumin level increased progressively at six and eight weeks after the captopril treatment period and was significantly higher than the pretreatment value (p < 0.05). The decrease in proteinuria did not coincide with a fall in blood pressure or any changes in creatinine clearance. We conclude that captopril does have a significant antiproteinuric effect in patients excreting heavy proteinuria with various glomerular diseases. However, the long term therapeutic efficacy and any renal protective effect of this drug remain to be proven.

Adult↗
PubMed1992

Single-center experience of unrelated living-donor renal transplantation in the cyclosporine era.

Renal transplantation from the unrelated living-donor might be an alternative when the cadaveric or related donor is not available, because graft and patient survival rates are superior to those of kidneys from cadaveric donors and even comparable to those from related donors. Among the many factors that might contribute to these excellent results, we believe that the good quality of kidneys (lacking preservation or ischemic injury) is the most important one. In addition, our criteria for patient selection requiring well-matched HLA typing might partially contribute to our success. For the successful renal transplantation program using unrelated-living donors, high ethical standards, accumulated experience from living-related donor transplantation, and dedicated professionalism are strongly recommended.

ABO Blood-Group System↗
PubMed1992

Effects of thyroidectomy on the hematocrit and blood viscosity in ovariectomized rats.

The hematocrit and blood viscosity were measured in ovariectomized (Ovx) rats following thyroidectomy or sham operation. Rats were thyroidectomized (Tx) or sham Tx immediately after ovariectomy. Three months later, Ovx, Ovx+Tx, and intact rats at proestrus stage were bled. Blood was collected by heart puncture in rats under ether anesthesia and heparinized. One month after the first bleeding, Ovx and Ovx+Tx rats were bled once again. the viscosity of whole blood and plasma was measured at various shear rates at 37 degrees C by means of a Mooney-Ewart viscometer. The hematocrit was determined by a microhematocrit centrifuge. The plasma osmolality was measured by a computerized micro-osmometer. Concentrations of plasma sodium and potassium were measured by a flame photometer. The concentration of plasma thyroid stimulating hormone (TSH) was measured by a radioimmunoassay. In Ovx+Tx rats, the plasma TSH concentration was higher, but the hematocrit and blood viscosity were lower than those in Ovx and proestrus rats. The levels of plasma sodium, osmolality and viscosity were not altered by ovariectomy and thyroidectomy. These results suggest that the lower blood viscosity in thyroidectomized rats is due to a reduction of hematocrit.

Animals↗
PubMed1991

Diazepam enhances intrasynaptosomal free calcium concentrations.

Synaptosomes prepared from brains of rats were incubated in different concentrations of diazepam under conditions designed to reduce the action of a reversed Na+/Ca2+ exchanger. In synaptosomes depolarized in the presence of added Ca2+, doses of diazepam ranging from 0.1 to 100 microM were found to significantly enhance Ca2+ levels measured with the fluorescent dye fura-2, compared to control incubations without drug. Furthermore, doses of diazepam as low as 1 microM significantly increased the concentration of Ca2+ in non-depolarized synaptosomes without added Ca2+ in the medium. The effects of depolarization and diazepam treatment were synergistic in increasing the levels of intrasynaptosomal Ca2+.

Analysis of Variance↗
PubMed1991

A morphometric and computer-assisted three-dimensional reconstruction study of neural tube formation in chick embryos.

The origin of the driving forces for neural tube formation remains uncertain but is currently thought to involve the participation of microfilament bundles situated in the apical ends of neuroepithelial cells. In the work presented here, we show how morphometric measurements that map local variations in the apical geometry of neuroepithelial cells (especially apical constriction) can provide information on the distribution of motive forces within the neuroepithelium during neural tube formation. When used in combination with computer-assisted, three-dimensional reconstruction, it becomes possible to analyze the morphometric data from a dynamic, three-dimensional perspective. As an example application of this method, we have used morphometry to evaluate the effects of ionomycin on the developing neuroepithelium. Treatment of early (stages 6-8) chick embryos with 5 microM ionomycin was found to cause rapid bending of the neuroepithelium within 1 min of exposure and a dramatic acceleration of the normal sequence of neural tube formation. Electron microscopy and morphometry revealed that this acceleration was coincident with a marked increase in the local degree of apical constriction of neuroepithelial cells, presumably a consequence of enhanced contractile activity of apical microfilament bundles. This work shows that transient elevation of free calcium levels can accelerate the usual sequential phases of NT formation. The rapidity of the response (hours of normal development reduced to minutes), increased prominence of apical microfilament bundles, and the enhanced degree of apical constriction strongly support a direct causal role for apical microfilament bundles and apical constriction of neuroepithelial cells in bending of the neuroepithelium.

Actin Cytoskeleton↗
PubMed1991

Detection of human papillomavirus genotypes in cervical neoplasia from Korean women using polymerase chain reaction.

The histopathologic features of cervical dysplasia (20 cases) and cervical carcinoma (15 cases) in Korean women were correlated with the presence of human papillomaviruses (HPVs) as determined by polymerase chain reaction technology on paraffin-processed specimens. A segment of the E6 open reading frame of several HPV types (HPV 6, 11, 16, 18, 31, 33, and 35) was amplified using primers which were synthesized to contain 50% G + C, in order to give optimum annealing for the amplification of HPVs. All specimens were also tested for amplification of the cellular beta-globin gene. HPV was found in 19 (54%) cases. The HPV types were HPV 6 in 1 case (3%), HPV 16 in 15 cases (43%), HPV 18 in 2 cases (6%), and HPV 33 in 3 cases (9%). HPV was identified in 16 of 25 (64%) beta-globin-positive and 3 of 10 (30%) beta-globin-negative tissues. HPV types 11, 31, and 35 were not detected in any of the specimens. HPV 6, 18, and 33 were detected only in preneoplastic lesions, and co-infection with these three viruses was observed in one case of severe dysplasia. HPV type 16 was found in 8 (40%) premalignant lesions and in 7 (47%) invasive carcinomas. These data indicate that HPVs are found along the entire spectrum of cervical neoplasia. HPV 16 was the predominant virus in invasive cancer of the cervix.

Adult↗
PubMed1991

Treatment of a large odontogenic keratocyst using the Brosch procedure.

The modified Brosch procedure has been described. It represents a reasonable alternative to resection or marsupialization when treating large OKC that occupy the molar, angle, and ramus regions of the mandible. Extraction of teeth affected by the lesion as well as generous removal of partially eroded bone and overlying soft tissues may contribute to lower recurrence rates. Cryosurgical or mechanical treatment of the bony cavity, which is well visualized using this technique, may also lead to improved long-term results. Treatment must be followed by continued, careful observation of the patient.

Adolescent↗
PubMed1991

Comparative study of affective disorders in three Asian countries. II. Differences in prevalence rates and symptom presentation.

This study used standardized diagnostic criteria and method to investigate both prevalence rates and nature of symptoms of depressive disorders in three Asian centres--Nagasaki, Shanghai and Seoul. Of the patients who visited a psychiatric clinic in each of the 3 centres for the first time, over 20% suffered from depression. Unlike previous reported prevalence rates for Asian countries, these results suggest that rates in Asia may not be much lower than those reported in Western countries. Although prevalence rates of depression were similar in all 3 centres, differences in symptoms were noted.

Adolescent↗
PubMed1991

Transport kinetics of glucose and alanine in renal brush-border membrane vesicles of cadmium-intoxicated rabbits.

Changes in transport kinetics of D-glucose and L-alanine were studied in renal luminal membrane vesicles isolated from cadmium-intoxicated rabbits. Cadmium intoxication was induced by subcutaneous injections of CdCl2 at a dose of 2 mg Cd/kg/day for 2-3 weeks. Brush-border membrane vesicles were prepared from renal outer cortex and outer medulla by Percoll gradient centrifugation. Cadmium intoxication resulted in a marked attenuation of Na(+)-dependent transports of D-glucose and L-alanine in both outer cortical and outer medullary brush-border membrane vesicles, and this was due to reduction in Vmax and not Km. Similar results were obtained in normal vesicles directly exposed to free cadmium. These results suggest that in long-term cadmium-exposed animals free cadmium ions liberated in the proximal tubular cytoplasm may directly impair brush-border membranes thereby reducing capacity of Na(+)-dependent transport systems for glucose and amino acids.

Alanine↗
PubMed1991

[Prevalence of Enterobius vermicularis infection and preventive effects of mass treatment among children in rural and urban areas, and children in orphanages].

An epidemiological study and mass treatments of Enterobius vermicularis infection among children near Wonju area of Kangwon province were carried out. The children were divided into 4 groups according to their residing localities; children in the mountainous area, rural area, urban area and in orphanage. They were examined by adhesive cellotape anal swab technique, and egg positive rates were obtained. The rates of egg reduction and re-infection rates after repeated mass treatments were also observed. The results obtained were as follows: 1. The overall egg positive rate of E. vermicularis in the first screening was 19.9% (251 out of 1,262 examinees; 19.7% in males and 20.1% in females). The positive rates were 13.0% in the mountainous area, 11.9% in the rural area, 15.1% in the urban (medium-sized) area and 61.9% in orphanages. 2. The highest positive rates were observed in the kindergarten children, and 1st and 2nd grade children of primary schools (26.2-32.2%), and the lowest rate (13.6%) in 6-year grade children of primary schools. 3. Cumulative detection rates from 3 repeated anal swabs at 4-5 days interval were higher (70.8%) than those from single anal swabs (50.0-59.2%). 4. Out of the examinees who showed the highest cumulative positive rate (70.8%), about 39.2% were consecutively positive in 3 anal swabs. Among different groups of children, the higher the total egg detection rates (87.5%), the higher the consecutive positive rates (71.9%). 5. A total of 2,609 (male: female = 1:12.4) worms were collected from 17 egg-positive cases treated with anthelmintics. The mean number of worms per child was 153 (range: 4-824).(ABSTRACT TRUNCATED AT 250 WORDS)

Child↗
PubMed1991

An analysis of 2361 cases of renal biopsy in Korea.

To evaluate the distribution pattern of renal diseases based on needle biopsy, we analyzed 2361 cases of renal biopsy and necropsy material examined at the Department of Pathology from 1973 to 1988. The average age was 21.1 years for males and 23.7 years for females. The adult cases comprised 60.2% and the child cases 39.8%. The male to female ratio was 1.6: 1 in adults and 2.3:1 in children. Glomerular diseases were 97.8% of the total; primary glomerulonephritis (GN) 59.8% and secondary GN 27.6% The major glomerular diseases, in descending order of frequency, were; minimal change nephrotic syndrome (MCNS; 24.2%), IgA nephropathy (IgAN; 17.8%), benign recurrent hematuria (BRH; 8.8%), membranous GN (MGN; 7.9%), acute poststreptococcal GN (APSGN; 7.3%), mesangioproliferative GN (MspGN; 5.5%), minimal mesangiopathy (5.5%), membranoproliferative GN(4.1%), and focal segmental glomerulosclerosis (FSGS; 2.7%). GN of systemic disease included 77 cases of lupus nephritis, 157 cases of Henoch-Schönlein purpura nephritis (HSPN) and 7 cases of systemic infection excluding Hepatitis B viral hepatitis. The most common glomerular diseases were MCNS, IgAN, MGN and MspGN in adults, and MCNS, BRH, HSP-N and APSGN in children. HBs antigenemia was found in 71 cases, of which MGN and IgAN were the most frequent. HBs antigenemia-associated MGN was prevalent in male children, whereas IgAN was prevalent in adults.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗