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Biomedical subjects

S K Kim

Publications and source records attributed to S K Kim.

At least 163 records · Page 9Linked to original sources
PubMed2001

Effect of ions and nucleotides on the interactions of yeast Rad51 protein with single-stranded oligonucleotides.

Rad51 protein is a eukaryotic homologue of RecA protein that is essential for homologous recombination. We developed a simple procedure for purifying yeast Rad51 protein, characterized its interaction with DNA, and compared it with those of RecA from Escherichia coli and Rad51 from higher eukaryotes. Fractionation of crude extract with 0.2% polyethylenimine eliminated contaminant proteins and nucleic acids, which can perturb the subsequent purification steps. Binding of Rad51 to single-stranded DNA was detected in solution by measuring the fluorescence anisotropy of a fluorescein probe attached to the 5' end of the oligonucleotides. The interaction was stabilized by ATP, as is that of RecA, but was neither stabilized by a non-hydrolysable analog of ATP, nor destabilized by ADP, unlike the interaction of RecA. This character was very similar to that of Xenopus XRad51.1, although the binding of yeast Rad51 to DNA was more sensitive to Mg(2+) ion in both the presence and absence of ATP, and was optimal at 5--10 mM Mg(2+). The dissociation of Rad51 protein from DNA is not, therefore, favored by the hydrolysis of ATP to ADP, in contrast to that of RecA. On the other hand, the high DNA-binding state of the Rad51-DNA complex promoted by ATP appeared to be short-lived. These features may be linked to the lower activity of Rad51 and the fact that Rad51 activity does not require the hydrolysis of ATP.

Adenosine Diphosphate↗
PubMed2001

The thin latissimus dorsi perforator-based free flap for resurfacing.

The authors present their experience with "thin" latissimus dorsi perforator-based free flaps for resurfacing defects. Perforator-based free flaps have been used for various kinds of reconstruction by presenting important donor structures. The thin latissimus dorsi perforatorbased free flap included only the skin and superficial adipose layer to reduce its bulkiness by dissection through the superficial fascial plane. This flap was used in 12 clinical cases, without flap necrosis or other serious postoperative complications. All of the patients were examined by preoperative power Doppler ultrasound in the spectral Doppler mode to search for the most reliable perforator. This noninvasive ultrasound technique determines the exact location and course of and ensures the reliable flow of the perforators; therefore, it greatly assists microsurgeons in saving operation time and in selecting the most suitable design for perforator flap reconstruction. We used perforators that were identified several centimeters from the lateral border of the latissimus dorsi muscle. The thin flap dimensions could be safely designed for flaps measuring up to 20 cm in length and 8 cm in width for primary closure of the donor site. Generally, a long pedicle is not required for resurfacing reconstructions, where small recipient arteries in the bed are acceptable for anastomosis with pedicles. However, pedicle dissection to the proximal vessels through the latissimus dorsi muscle was required when it was necessary to match the recipient vein for anastomosis. The authors conclude that this thin latissimus dorsi perforator-based free flap has great potential for resurfacing because of its constant thickness, easy elevation with the help of power Doppler ultrasound information, and proper flap size for moderate defects caused by scar contracture release, superficial tumor ablation, and so on.

Adolescent↗
PubMed2001

Endoscopically assisted, intraorally approached corrective rhinoplasty.

In the field of facial surgery, operations that require guesswork can result in unexpected complications. One example of such "blind" facial surgery is the lateral osteotomy procedure in corrective rhinoplasty. In most conventional corrective rhinoplasties, the postoperative results of a lateral osteotomy can be controlled by the surgeon's visual perception or manual dexterity; therefore, an experienced surgeon is indispensable in such elaborate operations. Until now, reports have focused on the endoscopic approach through the nasal dorsum or septum through the nostril. However, because of the difficulty in handling the endoscope with osteotomy instruments, it is considered difficult to perform a precise lateral osteotomy procedure using that approach. The authors think the intraoral endoscopic approach should be considered a viable alternative in corrective rhinoplasty. Through small, bilateral gingivobuccal incisions, both the piriform apertures and nasal bones can be easily exposed, and the exact level of the lateral osteotomy can be confirmed directly under the endoscope. The lateral osteotomy is made simply with a reciprocating saw, and symmetrical cutting can be ascertained during the operation. Sometimes, a particular osteotomy level or the proper repositioning of osteotomed segments can be readily evaluated with assistance from the endoscope during the operation. Eleven cases using this procedure were performed over the past 3 years. These endoscopic repairs for a deviated nose were quite helpful for visual confirmation and accurate correction. No complications occurred when using the endoscope with this procedure.

Adult↗
PubMed2001

Mapping the sequences that mediate interaction of the equine herpesvirus 1 immediate-early protein and human TFIIB.

The sole immediate-early (IE) gene of equine herpesvirus 1 encodes a 1,487-amino-acid (aa) regulatory phosphoprotein that independently activates expression of early viral genes. Coimmunoprecipitation assays demonstrated that the IE protein physically interacts with the general transcription factor TFIIB. Using a variety of protein-binding assays that employed a panel of IE truncation and deletion mutants expressed as in vitro-synthesized or glutathione S-transferase fusion proteins, we mapped a TFIIB-binding domain to aa 407 to 757 of the IE protein. IE mutants carrying internal deletions of aa 426 to 578 and 621 to 757 were partially defective for TFIIB binding, indicating that aa 407 to 757 may harbor more than one TFIIB-binding domain. The interaction between the IE protein and TFIIB is of physiological importance, as evidenced by transient-cotransfection assays. Partial deletion of the TFIIB-binding domain within the IE protein inhibited its ability to activate expression of the viral thymidine kinase gene, a representative early promoter, and of the IR5 gene, a representative late promoter, by greater than 20 and 50%, respectively. These results indicate that the interaction of the IE protein with TFIIB is necessary for its full transactivation function and that the IE-TFIIB interaction may be part of the mechanism by which the IE protein activates transcription.

Animals↗
PubMed2001

Births of freemartins derived from embryos reconstructed with ear fibroblasts.

Although the combination of artificial insemination (AI) and embryo transfer (ET) is effective for preventing large offspring syndrome in clone cattle production, it may cause freemartinism. In this study, 51 reconstructed embryos were transferred to artificially inseminated recipients. Of those 9 twin pregnancies, three delivered male and female offsprings. The females had tufts of long coarse hair and short blind pouch at the vaginal end. At necropsy, hypoplastic testicles and epididymis, which connected to the uterus through the spermatic cord, were found and seminal vesicles were also noted. All females had mixed sex chromosome configuration (60, XX and 60, XY). These results suggest that the combined ET program can cause freemartinism, which reduces the efficiency of clone cattle production.

Animals↗
PubMed2001

Differentiation between bone infarction and acute osteomyelitis in children with sickle-cell disease with use of sequential radionuclide bone-marrow and bone scans.

BACKGROUND: The differentiation of bone infarction from acute osteomyelitis in patients with sickle-cell disease is challenging, as the clinical presentations of the two conditions are similar and imaging and laboratory studies are of limited value. METHODS: A combination of radionuclide bone-marrow and bone scans was performed sequentially within a twenty-four-hour period (with one exception) to aid in the differentiation between bone infarction and osteomyelitis in seventy-nine consecutive episodes of acute bone pain in children with sickle-cell disease. RESULTS: Seventy cases of bone infarction were diagnosed on the basis of decreased uptake on the bone-marrow scan and abnormal uptake on the bone scan at the site of pain. Antibiotic administration was discontinued in sixty-six of the seventy cases after the imaging results were obtained, and the bone pain resolved. In four of the seventy-nine cases, there was normal uptake on the bone-marrow scan and abnormal uptake on the bone scan at the site of pain, findings that were suggestive of acute osteomyelitis. In three of these cases, osteomyelitis was proven by culture, and the symptoms in all four resolved with antibiotic treatment. In five of the seventy-nine cases, the bone-marrow and bone scans were normal and thought to indicate neither osteomyelitis nor bone infarction; in all of these cases, the symptoms resolved without the use of antibiotics. CONCLUSIONS: These findings suggest that osteomyelitis can be differentiated from bone infarction in children with sickle-cell anemia and acute bone pain by a combination of sequential bone-marrow and bone scintigraphy.

Acute Disease↗
PubMed2001

Effects of insulin and antioxidant on plasma 8-hydroxyguanine and tissue 8-hydroxydeoxyguanosine in streptozotocin-induced diabetic rats.

Cumulating evidence suggests that enhanced oxidative stress may contribute to diabetic angiopathy. The levels of 8-hydroxydeoxyguanosine (8-OHdG) and 8-hydroxyguanine (8-OHG), indicators of oxidative DNA damage, in tissue or body fluid are increased in diabetic patients. However, it is unclear whether plasma 8-OHG correlates with tissue 8-OHdG and whether insulin or antioxidant treatment reduces plasma 8-OHG in diabetic state. In this study, we measured the 8-OHG levels in plasma as well as the 8-OHdG levels in liver and kidney in streptozotocin-induced diabetic rats (DR) treated with insulin (DR+I), insulin and probucol (DR+I/P), or insulin and vitamin E (DR+I/E). There was a correlation between plasma 8-OHG levels and tissue 8-OHdG levels (plasma 8-OHG vs. liver 8-OHdG: r = 0.64, P < 0.001; plasma 8-OHG vs. kidney 8-OHdG: r = 0.38, P = 0.06). DR had levels of plasma 8-OHG that were three times higher than control rats (CR), whereas they had levels of tissue 8-OHdG that were approximately 1.5-2 times higher. Plasma 8-OHG levels in DR were almost normalized by insulin treatment, although insulin partially corrected hyperglycemia (plasma 8-OHG: CR 3.3 +/- 2.7 pmol/ml; DR 10.4 +/- 2.3 pmol/ml, P < 0.05 vs. CR; DR with insulin 3.6 +/- 1.0 pmol/ml, P < 0.05 vs. DR). However, tissue 8-OHdG levels in DR were significantly decreased by combined treatment with insulin and antioxidant (probucol or vitamin E), but not by insulin treatment alone. This data suggests that plasma 8-OHG could be a useful biomarker of oxidative DNA damage in diabetic subjects. The mechanism of differential response of plasma 8-OHG and tissue 8-OHdG to insulin and antioxidant treatment remains to be elucidated.

8-Hydroxy-2'-Deoxyguanosine↗
PubMed2001

The effect of oxygen on retinal degeneration in wild-type and hsp70.1 knockout neonatal retinal degeneration mice.

The present study examined the effect of oxygen on photoreceptor degeneration in the retina of heat shock protein 70.1 (hsp70.1) knockout type and wild-type retinal degeneration (rd) mice. All the neonatal rd mice were exposed to hyperoixa for 5 days after birth, and then were returned to room air before being sacrificed. At the postnatal 10, 14, 18, and 21 days, the ratio of outer nuclear layer (ONL) thickness to total retinal thickness was compared between hsp70.1 knockout type and wild type. The retina was also examined for DNA fragmentation by TdT-mediated biotin-dUTP nick-end labeling (TUNEL). In hsp70.1 knockout type, the ratio of ONL to total retinal thickness was higher than that in the wild type at each time. There was the remarkable difference in the number and distribution of TUNEL-positive cells between hsp70.1 knockout type and wild type rd mice. In conclusion, an oxygen-induced modulation of the rate of photoreceptor degeneration was more marked in the hsp70.1 knockout type than wild type rd mice.

Animals↗
PubMed2001

Mid-term effects of trabeculectomy with mitomycin C in neovascular glaucoma patients.

Twenty four eyes from 23 neovascular glaucoma (NVG) patients, who underwent trabeculectomy with 0.2 or 0.4 mg/ml MMC in least the previous 6 months, were examined in order to evaluate the mid-term effects of a trabeculectomy with mitomycin C (MMC) in NVG. Success defined when an intraocular pressure (IOP) < 22 mmHg and > 5 mmHg with or without medication was observed. The mean IOP was reduced from 46.8+/-12.9 mmHg preoperatively to 18.2+/-12.0 mmHg at the last follow-up (mean = 25.8 months). The overall success rates at 1-, 3-, 6-, 9-, and 12-months after surgery were 71%, 58%, 50%, 29%, 29% respectively. The number of anti-glaucoma medications administered was significantly reduced from 2.6+/-0.7 preoperatively to 0.9+/-1.0 postoperatively (Wilcoxon signed rank test, p = 0.005). In addition both the intraoperative MMC concentration and application time had no influence on lowering the IOP (logistic regression analysis, p = 0.228, 0.910, respectively). There was a similar incidence of postoperative complications in both the success and failure group. These results suggest that a trabeculectomy with MMC is an effective surgical procedure in NVG patients and the MMC concentration is not crucial for reducing the IOP postoperatively.

Adult↗
PubMed2001

Gastric lymphangioma.

Gastric lymphangioma is a rare benign gastric tumor composed of unilocular or multilocular lymphatic spaces. On gastrofiberscopy a submucosal tumor covered with smooth transparent normal mucosa is revealed in the stomach with or without a stalk. Endoscopic ultrasonography has become an indispensable tool for differentiating these gastric tumors. Treatment of lymphangioma depends on its size, location, and presence of complications. Endoscopic resection is safe and easy and plays an important role in confirming the diagnosis and treatment of the tumors especially of small-sized ones. We report a case of gastric lymphangioma in a 68-yr-old woman who presented with nausea and vague epigastric discomfort for two months. She was diagnosed by gastrofiberscopy with endoscopic ultrasonography and treated successfully with endoscopic resection by strip biopsy method.

Aged↗
PubMed2001

Triple marker screening for fetal chromosomal abnormalities in Korean women of advanced maternal age.

The purpose of this article is to assess the value of maternal serum triple marker screening of alpha-fetoprotein (AFP), human chorionic gonadotropin (hCG), and unconjugated estriol (uE3) for the prenatal diagnosis of fetal chromosomal abnormalities in Korean women of advanced maternal age. Maternal sera were collected from 458 pregnant Korean women aged 35 between 15 and 20 weeks gestation before amniocentesis. A patient- specific second trimester risk for fetal Down's syndrome was calculated using the median values for AFP, hCG, uE3 and maternal age. Twelve fetal chromosomal abnormalities were identified. These included six cases of trisomy 21, one case of 46,XY/47,XY,+21, two cases of trisomy 18, one case of trisomy 13, and two cases of 45, X. A cutoff level of 1:200 detected 85.7% (6/7) of the cases of Down's syndrome and 20% (1/5) of the other aneuploidies, with a 27.3% false positive rate. However, a cutoff level of 1:270 did not result in any gains in detecting Down's syndrome or other aneuploidies at the expense of a false positive rate of 34.3%. Second trimester triple marker testing is an effective screening tool for detecting fetal Down's syndrome in Korean women > or = 35 years old. However, it is not an effective screening tool for non-Down's chromosomal abnormalities.

Adult↗
PubMed2001

Torsion of the pregnant uterus.

A 31-year-old woman, with a history of previous cesarean section and right oophorectomy, was admitted for a repeat cesarean section. After the commencement of surgery uterine torsion was diagnosed because of the anterior position of the remaining left ovary and tube, the absence of normal uterovesical peritoneum, and extremely engorged vessels in the lower uterine surface. Posterior classical hysterotomy was performed and a healthy female baby was delivered. Following delivery of the baby and suturing the incision site of the uterus, the contracted uterus was detorted and put back in the pelvic cavity. Extreme uterine torsion of 180 degrees at term is a rare obstetric event. This paper presents a case of uterine torsion at full term pregnancy in which the delivery and repositioning of the uterus was successful.

Adult↗
PubMed2001

A case with balanced chromosome rearrangement involving chromosomes 9, 14, and 13 in a woman with recurrent abortion.

A phenotypically normal couple was referred for cytogenetic evaluation due to three consecutive first-trimester spontaneous abortions. Chromosomal analysis from peripheral blood was performed according to standard cytogenetic methods using G-banding technique. The husband's karyotype was normal. The wife's karyotype showed a balanced complex chromosome rearrangement (CCR) involving chromosomes 9, 14, and 13. There were three breakpoints: 9p21.2, 14q21, and 13q12.2. The karyotype was designated as 46, XX, t (9;14;13)(p21.2;q21;q12.2). Fluorescence in situ hybridization (FISH) analysis with chromosome-specific libraries of chromosomes 9, 14, and 13 was performed to confirm this rare chromosome rearrangement. The result of FISH coincided with that obtained by standard cytogenetic techniques.

Abortion, Habitual↗
PubMed2001

The detection of p53 gene mutation using a microdissection technique in primary intracranial germ cell tumors.

Using a microdissection technique, the contribution of the p53 mutation to tumorigenesis and prognosis in each histological subtype of the intracranial germ cell tumors (GCTs) was evaluated. Nineteen patients had primary intracranial GCTs, including 4 germinomas (GEs), 4 teratomas (TEs), 1 mixed tumor of GE and TE, and 10 mixed GCTs containing non-germinomatous malignant germ cell tumors (NG-MGCTs). After microdissection of specific subtypes, genomic DNA was screened for mutations in exons 5-8 of the p53 gene, using the dideoxyfingerprinting (ddF) followed by direct DNA sequencing. The direct sequencing revealed a total of six mutations in PCR products derived from the five cases (26%) which showed mobility shifts in ddF. Among the six mutations detected, four were missense mutations and two were silent. Missense mutations of the p53 gene tended to occur more frequently in the NG-MGCT component than in the GE or TE components (3/15 vs. 1/12 vs. 0/13). The incidence of missense mutations was not different between the survivors (3/13) and the deceased (1/6). This study suggests the possible role of the p53 gene in the tumori-genesis of NG-MGCT. However, p53 gene mutation did not correlate with the prognosis of NG-MGCT.

Adult↗
PubMed2001

Quantification of regional myocardial blood flow using dynamic H2(15)O PET and factor analysis.

UNLABELLED: Because the use of factor analysis has been proposed for extracting pure physiologic temporal or spatial information from dynamic nuclear medicine images, factor analysis should be capable of robustly estimating regional myocardial blood flow (rMBF) using H2(15)O PET without additional C15O PET, which is a cumbersome procedure for patients. Therefore, we measured rMBF using time-activity curves (TACs) obtained from factor analysis of dynamic myocardial H2(15)O PET images without the aid of C15O PET. METHODS: H2(15)O PET of six healthy dogs at rest and during stress was performed simultaneously with microsphere studies using 85Sr, 46Sc, and 113SN: We performed factor analysis in two steps after reorienting and masking the images to include only the cardiac region. The first step discriminated each factor in the spatial distribution and acquired the input functions, and the second step extracted regional-tissue TACS: Image-derived input functions obtained by factor analysis were compared with those obtained by the sampling method. rMBF calculated using a compartmental model with tissue TACs from the second step of the factor analysis was compared with rMBF measured by microsphere studies. RESULTS: Factor analysis was successful for all the dynamic H2(15)O PET images. The input functions obtained by factor analysis were nearly equal to those obtained by arterial blood sampling, except for the expected delay. The correlation between rMBF obtained by factor analysis and rMBF obtained by microsphere studies was good (r = 0.95). The correlation between rMBF obtained by the region-of-interest method and rMBF obtained by microsphere studies was also good (r = 0.93). CONCLUSION: rMBF can be measured robustly by factor analysis using dynamic myocardial H2(15)O PET images without additional C15O blood-pool PET.

Animals↗
PubMed2001

Changes in serum lipid concentrations during iron depletion and after iron supplementation.

To investigate the effects of body iron depletion and iron supplementation on serum lipid concentrations, hematologic indices, iron markers, and serum lipid profiles were measured in 427 girls, age 14-19 yr. There were no significant differences in serum lipid concentrations between subjects with moderate iron deficiency anemia (blood Hb < 12.0 g/dL) and healthy controls. However, serum total cholesterol concentration (mean +/- SD, 148 +/- 16 mg/dL) in severely anemic subjects with blood Hb < 8.0 g/dL was significantly lower than in subjects with blood Hb > or = 14.0 g/dL (170 +/- 17 mg/dL) (p < 0.01). Moreover, serum triglyceride concentration in subjects with blood Hb > 14.0 g/dL was 2-fold higher than in the severely anemic subjects. Mean values of serum total cholesterol and triglyceride (149 +/- 17 mg/dL and 58 +/- 22 mg/dL) in girls with severe anemia were significantly elevated after iron supplementation (164 +/- 17 mg/dL and 98 +/- 26 mg/dL) (p < 0.01, respectively). In the severely anemic subjects, blood Hb concentration was correlated with serum total cholesterol (r = 0.49, p < 0.01) and triglyceride concentrations (r = 0.51, p < 0.01). These findings indicate that severe iron deficiency anemia in girls is attended by decreased concentrations of serum total cholesterol and triglyceride, and that these reduced serum lipid levels return to normal following iron supplementation.

Adolescent↗