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Biomedical subjects

R Kim

Publications and source records attributed to R Kim.

At least 73 records · Page 4Linked to original sources
PubMed2000

Validation of K x-ray fluorescence bone lead measurements by inductively coupled plasma mass spectrometry in cadaver legs.

K x-ray fluorescence (KXRF) systems are being used in a growing number of epidemiologic studies to measure bone lead levels as a biological marker of accumulated lead exposure. Although validation of the KXRF technique in lead-doped phantoms and bare bone specimens has been repeatedly demonstrated, few studies have compared KXRF to chemical measurements of actual intact cadaver limbs (with skin and soft tissues). In this study, lead levels in eight amputated human legs were measured by KXRF; after dissection, levels in the bare bones were again measured by KXRF and then by inductively coupled plasma mass spectrometry (ICP-MS). We observed close agreement between the KXRF and ICP-MS measurements with correlation coefficients for both the tibia and patella greater than 0.9. In this study we provide further support for the validity of KXRF measurements, particularly with respect to the patella.

Aged↗
PubMed2000

Septic arthritis of the hip associated with atopic dermatitis. A case report.

We report a case of septic arthritis of the hip associated with atopic dermatitis. A 15-year female felt a pain in the right hip with unknown cause on May 11, 1998. The pain subsequently became aggravated, and she was admitted to our hospital on May 18. She has had atopic dermatitis since 4 years of age. She showed generalized dermatitis with desquamation and numerous scratch marks. A culture of both skin and joint fluid revealed Staphylococcus aureus. Physical examination revealed tenderness in Scarpa triangle and restricted range of motion. Immunological serology showed an increase in eosinophils and immunoglobulin E, and a decreased reaction of lymphocyte blastoid transformation. Computed tomography (CT) and MRI showed a joint effusion in the right hip. She was diagnosed as having septic arthritis of the hip. Intravenous drip of Cefazolin of 2g was started on the first day of hospitalization and joint irrigation was done on the second day. CRP became negative at 4 weeks, but joint effusion was shown on CT. Additional joint irrigation with Amicamycin (200 mg) was done. As the joint fluid culture became negative, range of motion exercises were started at 6 weeks. She was discharged with a long-leg brace applied at 8 weeks. At 13 months after onset, she had complete relief of the pain and normal activities of daily living. No destructive changes in the hip were found on X-ray examination or MRI. In the present case, an abnormal immune system associated with atopic dermatitis as well as the habit of scratching eruptions may have led to hematogenous spread of skin infection, and caused septic arthritis of the hip.

Adolescent↗
PubMed2000

Validity and cost-effectiveness of diagnostic procedures in CS2 poisoning.

To determine relatively useful diagnostic procedures of carbon disulfide (CS2) poisoning in terms of validity and cost-effectiveness, several diagnostic tests are evaluated on 1,552 people by prevalence ratio (exposed/nonexposed), dose-response relationship, sensitivity and specificity, and the cost of the tests. Several symptoms with high kappa indices are found to be useful in various combinations, showing a consistent dose-response relationship and high exposed-nonexposed ratio. In clinicopathologic tests on functions of the kidney, liver and hematopoietic systems, eight items out of 22 have been shown to have significant dose-response relationship, mostly in liver function tests. A thorough dental examination failed to identify any useful indicator peculiar to the CS2 poisoning. Unlike Western people, the prevalence of coronary heart disease among Koreans was too low to be useful in the diagnosis of CS2 poisoning. Among four elective tests, i.e., Minnesota Multiphasic Personality Inventory (MMPI), Brain magnetic resonance imaging (MRI), nerve conduction velocity (NCV), and fluorescent angiography (FAG), the NCV appeared to be a more sensitive and specific test than the others are. Combinations of the tests improved the probability of diagnosing CS2 poisoning cases when any one test out of four was positive. Addition of other valid tests increased the probability of excluding non-cases. It was concluded that diagnosis of CS2 poisoning could be made validly and inexpensively if the diagnostic tests were carefully chosen step by step.

Adolescent↗
PubMed2000

Overcoming of multidrug resistance by introducing the apoptosis gene, bcl-Xs, into MRP-overexpressing drug resistant cells.

Multidrug resistance associated protein (MRP) is one of drug transport membranes that confer multidrug resistance in cancer cells. Multidrug resistance has been known to be associated with resistance to apoptosis. In this study, using MRP overexpressing multidrug resistant nasopharyngeal cancer cells, we examined the expression of apoptosis related genes including p53, p21WAF1, bax and bcl-Xs between drug sensitive KB and its resistant KB/7D cells. We also examined whether the introduction of apoptosis related gene could increase the sensitivity to anticancer drugs in association with apoptotic cell death. The relative resistances to anticancer drugs in KB/7D cells evaluated by IC50 values were 3.6, 61.3, 10.4 and 10.5 to adriamycin (ADM), etoposide (VP-16), vincristine (VCR) and vindesine (VDS), respectively. The resistance to anticancer drugs in KB/7D cells was associated with the attenuation of internucleosomal DNA ladder formation in apoptosis. Of important, the mRNA expression of bcl-Xs gene in KB/7D cells was decreased in one-fourth as compared to that of KB cells among the apoptosis genes. The mRNA expression of bcl-Xs gene in a bcl-Xs transfected clone (KB/7Dbcl-Xs) was increased about 2-fold compared to that of KB/7Dneo cells, while the mRNA expression of MRP gene was not significantly different in KB/7bcl-Xs and KB/7Dneo cells. The sensitivities to anticancer drugs including ADM, VCR and VDS except VP-16 were increased in KB/7Dbcl-Xs cells, in turn, the relative resistance in KB/7Dbcl-Xs cells was decreased to 1.4, 4.0, and 3.0 in ADM, VCR and VDS, respectively, as compared to those of KB/7Dneo cells. Of interest, the studies on the accumulation of [3H]VCR showed that the decrease of [3H]VCR accumulation in KB/7Dbcl-Xs was not significantly different from that of KB/7Dneo cells. Collectively, these results indicated that the mechanism(s) of drug resistance in KB/7D cells could be explained at least by two factors: a) reduced drug accumulation mediated by MRP; b) resistance to apoptosis due to the decreased expression of the bcl-Xs gene. These results also indicated that the multidrug resistance mediated by MRP might be partially overcome by introducing apoptosis gene into drug resistant cells without modulation of MRP function in drug accumulation.

ATP-Binding Cassette Transporters↗
PubMed2000

Venous outflow and inflow resistance in health and venous disease.

PURPOSE: The purpose of this study was to develop a physiologic method to measure outflow and inflow from the lower extremities and thus to quantify the degree of venous valvular insufficiency and venous obstructive disease. METHODS: Calibrated photoplethysmography was used in combination with passive changes in hydrostatic pressure, by leg elevation followed by repositioning of the leg to the original sitting position. With the principle of venous occlusion plethysmography, timed volume changes were then used to calculate the outflow and inflow. The inflow and outflow units were the percentage of optical reflectance (%OR) per minute. The respective resistances were calculated by identifying the hydrostatic pressure distance from the third intercostal space to the probe site that is inducing these site changes. The resistance units were millimeters of Mercury x minutes per %OR. RESULTS: Four groups of subjects were examined: normal individuals, patients with venous valvular insufficiency, deep venous thrombosis, and a combination of both. The most significant differences in outflow values were found between the control group (81.77% OR/min) and the deep venous thrombosis group (28.47% OR/min). In contrast, the most significant differences in inflow values were found between the control group (9. 67% OR/min) and the venous valvular insufficiency group (108.61% OR/min). The resistances changed correspondingly. CONCLUSION: The application of calibrated photoplethysmography in conjunction with induced changes in leg hydrostatic pressure proved to be an effective physiologic method to noninvasively quantify venous hemodynamics in normal control subjects, patients with venous valvular insufficiency, venous obstructive disease, or both.

Blood Volume↗
PubMed2000

Effect of low level lead exposure on hyperuricemia and gout among middle aged and elderly men: the normative aging study.

OBJECTIVE: To determine whether longterm lead accumulation is associated with hyperuricemia and gouty arthritis among middle aged and elderly men. METHODS: In a retrospective cohort study, 777 male participants were evaluated between August 1991 and October 1996 in the Department of Veterans Affairs Normative Aging Study, a 35 year longitudinal study of aging. We examined the development of gout and an increased uric acid level in relation to lead, adjusting for other known risk factors. Lead levels were measured in blood and by K x-ray fluorescence (K-XRF) technique in tibial (cortical) and patellar (trabecular) bone. RESULTS: Blood lead levels in this mostly Caucasian (97%) population were low (mean 5.9 microg/dl, SD 3.5). Bone lead levels were comparable to those described in other general populations. In a multivariate analysis adjusting for the risk factors, age, body mass index, diastolic blood pressure, alcohol intake, and serum creatinine level, there was a positive association between patellar bone lead and uric acid levels (p = 0.02). Of 777 participants, 52 (6.7%) had developed gouty arthritis. In logistic regression of similar covariates, body mass index (p < 0.0001) and serum creatinine level (p = 0.005) were the strongest determinants of gout; neither bone nor blood lead levels predicted gout in this cohort. CONCLUSION: The longterm accumulation of lead is associated with an increased uric acid level in middle aged and elderly men. However, this study shows no association between lead and gouty arthritis at the levels arising from community exposure.

Age Factors↗
PubMed2000

Non-invasively determined ambulatory venous pressure.

In view of the resemblance of exercise-induced plethysmographic changes with those obtained by direct venous pressure measurement, we decided to use a combination of photoplethysmography (PPG) and hydrostatic pressure calibration to determine the PPG/pressure relationship. A standard foot dorsiflexion exercise involving stepwise position changing was performed which induced hydrostatic pressure changes that were recorded as the heart-probe distance. A logarithmic PPG/pressure relationship was identified and the resulting ambulatory venous pressure (AVP) was obtained from the PPG/pressure curve. Simultaneous direct AVP was recorded in 14 patients scheduled for venous surgery. 'Non-invasive AVP only' was determined in 24 normal control subjects with a mean value of 19.24 mmHg (+/-8.79 SD). In the patient group, the direct AVP values were 40.00 mmHg (+/-10.83 SD) compared with the PPG values of 33.07 mmHg (+/-12.94 SD). The resulting correlation was r = 0.8850. By utilizing stepwise leg elevation, a reliable PPG/pressure curve can be established which, in turn, permits AVP determination. It is suggested that this non-invasive AVP determination may serve as a screening test to evaluate non-invasively venous hemodynamics.

Blood Pressure Monitoring, Ambulatory↗
PubMed1999

Expression, purification and preliminary X-ray analysis of a fibrillarin homolog from Methanococcus jannaschii, a hyperthermophile.

Fibrillarin plays a central role in ribosome biogenesis as a ribosomal RNA-processing protein. A Methanococcus jannaschii homolog of fibrillarin has been overexpressed, purified and crystallized. Crystals belong to the C2 space group with unit-cell parameters a = 121.4, b = 43.2, c = 55.3 A, beta = 96.9 degrees. Under flash-frozen conditions and using synchrotron radiation, the crystals diffract to 1.8 A resolution. For structural determination, a selenomethionine derivative of the protein has also been crystallized.

Archaeal Proteins↗
PubMed1999

Clinical and pathological evidence for a frontal variant of Alzheimer disease.

OBJECTIVE: To evaluate the clinical and pathological features of a subgroup of patients with Alzheimer disease (AD) who exhibited early and disproportionately severe impairments on tests of frontal lobe functioning. We hypothesized that these patients would exhibit a greater degree of either neurofibrillary tangle (NFT) or senile plaque pathology in the frontal lobes than would patients with typical AD. DESIGN AND OUTCOME MEASURES: We examined the neuropsychological profiles and senile plaque and NFT accumulation in the frontal, entorhinal, temporal, and parietal cortices in 3 patients with AD who exhibited disproportionate frontal impairments during early stages of dementia (frontal AD) and 3 matched patients with typical AD (typical AD). RESULTS: Compared with the typical AD group, the frontal AD group performed significantly worse on 2 tests of frontal lobe functioning and on the Wechsler Adult Intelligence Scale-Revised Block Design test. No significant group differences were found on other tests. Analysis of brain tissue samples demonstrated that, despite comparable entorhinal, temporal, and parietal NFT loads, the frontal AD group showed a significantly higher NFT load in the frontal cortex than the typical AD group. Senile plaque pathology in the frontal and entorhinal cortices did not differentiate the 2 groups. CONCLUSIONS: We identified a subgroup of patients with pathologically confirmed AD who presented in the early stages of dementia with disproportionate impairments on tests of frontal lobe functioning and had a greater-than-expected degree of NFT pathology in the frontal lobes, suggesting the existence of a frontal variant of AD that has distinctive clinical and pathological features.

Aged↗
PubMed1999

Characterization of vascular gene transfer using a novel cationic lipid.

INTRODUCTION: Cationic liposomes are an alternative non-viral vector for gene therapy, but several factors affect transfection efficiency. A novel cationic lipid, o-ethyldioleoylphosphatidylcholinium (EDOPC), was studied for characterization of the time course and effects of lipid composition, concentration, charge ratio, mixing techniques, passage number, and stimulated state on transfection of human vascular cells, represented by human umbilical vein endothelial cells (HUVEC). METHODS: HUVEC cultures were seeded at a density of 45,000 cells/well in 24-well plates and incubated overnight. Triplicate wells were transfected with samples of EDOPC/reporter plasmid for 2 h, followed by a 24-h expression time, which was the peak expression time point in an initial time-course experiment. Measuring luciferase in cell lysates quantitated gene expression. RESULTS: Transfection of HUVEC with EDOPC was optimal with a concentration of 100 microgram lipid/well, ratio of 3:1 EDOPC:plasmid, fractional mixing of lipid and plasmid, centrifugation, and incubation in serum-free media. Transfections in sequential passages showed striking decreases in gene expression and regression analysis revealed the relationship: RLU = 120,000 - (10, 400 x passage number), r(2) = 0.947. HUVEC activated by cytokine stimulation remain susceptible to gene transfer specifically with EDOPC. SUMMARY: During transfection of HUVEC with cationic lipid species, an increase in passage number is associated with linear reduction in luciferase expression, and hence passage number must be controlled in comparative experiments. Characteristics of EDOPC may permit site-specific efficient transfection of activated human vascular cells that can be isolated from serum by mechanical methods.

Blood Proteins↗
PubMed1999

Fatty marrow conversion of the proximal femoral metaphysis in osteonecrotic hips.

To determine whether fatty marrow conversion of the proximal femoral metaphysis is related to osteonecrosis of the femoral head using a marrow conversion index ([signal intensity of the proximal femoral metaphysis/signal intensity of the greater trochanter] x 100 in T1 weighted magnetic resonance images), a case control study was conducted on 42 osteonecrotic hips in 28 patients. The 28 patients (42 osteonecrotic hips) were matched with 84 control patients (84 normal hips) for gender, age (5-year range), and time of presentation (1-year range). The marrow conversion index was measured in each hip studied. The index was 90.2% (standard deviation, 8.2%) in osteonecrotic hips and 75.1% (standard deviation, 9.1%) in matched controls. By conditional logistic regression, a 5% increase in the index was associated with 3.6 times increase of the odds ratio of osteonecrosis and a 10% increase with a 12.9 times increase of the odds ratio. The marrow conversion index, which reflects the ratio of fatty marrow conversion of the proximal femoral metaphysis to that of the greater trochanter measured on T1 weighted magnetic resonance images, is increased in osteonecrotic hips.

Adipose Tissue↗
PubMed1999

Bone marrow edema and associated pain in early stage osteonecrosis of the femoral head: prospective study with serial MR images.

PURPOSE: To determine whether the marrow edema around focal osteonecrosis on magnetic resonance (MR) images is associated with clinical symptoms. MATERIALS AND METHODS: Thirty-three patients with 37 hips showing early stage osteonecrosis of the femoral head were followed up at 3-month intervals with clinical evaluation, conventional radiography, and serial MR imaging. RESULTS: Seven (50%) of 14 symptomatic hips showed marrow edema around focal osteonecrosis on initial MR images, whereas only one (4%) of 23 asymptomatic hips showed edema (P < .01). Six (86%) of seven hips that were moderately to severely painful were associated with surrounding marrow edema. All eight hips showing osteonecrosis with marrow edema at the initial MR examination had joint effusion and exhibited intense radionuclide uptake in the proximal femur, which corresponded to the extent of edema on MR images. In all eight hips, the marrow edema resolved on follow-up MR images, and the pain subsided with the resolution of edema. CONCLUSION: The results of this study suggest that the combination of marrow edema of the proximal femur and focal osteonecrosis of the femoral head are strongly associated with hip pain in early stage osteonecrosis, even prior to collapse. Pain improvement usually parallels the resolution of edema.

Adolescent↗
PubMed1999

Factors relating to readmission of term and near-term neonates in the first two weeks of life. Early Discharge Survey Group of the Health Professional Advisory Board of the Greater New York Chapter of the March of Dimes.

AIMS: A multisite study of term and near term infants readmitted in the first two weeks of life to 9 New York City area hospitals in 1995 was conducted to evaluate factors related to readmission, including length of newborn stay. RESULTS: Of the 30,884 infants born at the 9 study hospitals 391 newborns were readmitted. The major admission diagnoses were infection, 40.7%, hyperbilirubinemia, 39.1%, and feeding and/or gastrointestinal problems, 10.5%. In the first week, 65.1% of readmissions were for hyperbilirubinemia and 19.1% were for infection or suspected sepsis. In the second week, 67.8% of readmissions were for infection and 7.6% were for hyperbilirubinemia. Hyperbilirubinemia was the most frequent diagnosis for White and Asian infants, while infection was most frequent for African-American and Hispanic infants. Age at readmission was younger and the interval from discharge was shorter for infants with hyperbilirubinemia. Abnormalities which should have precluded early discharge included feeding difficulties, cyanotic congenital heart defects, hemolytic disease of the newborn, early jaundice or early high bilirubin levels. CONCLUSION: Attention to identification of infants at risk and programs such as lactation counseling and universal screening for bilirubin (with appropriate interpretation) prior to discharge could have reduced the necessity for readmission regardless of the newborn length of stay.

Adolescent↗
PubMed1999

Activation and the interaction of proapoptotic genes in modulating sensitivity to anticancer drugs in gastric cancer cells.

Taxotere (Docetaxel) is a novel microtubulin inhibitor which is currently in phase II/III clinical trial. We found that the sensitivity to taxotere was correlated with apoptotic cell death determined by the internucleosomal DNA ladders in gastric cancer cell lines. The treatment of taxotere activated proapoptotic genes such as bcl-Xs and bax genes. The relationship between the mRNA induction of bcl-Xs and bax genes and the internucleosomal DNA ladders by taxotere was significant, respectively (p<0.05). The introduction of bcl-Xs gene into MKN45 gastric cancer cells increased the sensitivity to VP-16 and taxotere 2-3-fold in the IC50 values, whereas the introduction of bax gene increased the sensitivity to CDDP, VP-16 and taxotere 2-5-fold in the IC50 values, as compared to that of the Neo-transfected MKN45 cells. The mRNA overexpression of bax gene was found in the bcl-Xs-transfected cells. Likewise, the mRNA overexpression of bcl-Xs gene was also found in the bax-transfected cells. These results indicate that the activation of bcl-2 family genes such as bcl-Xs and bax plays a crucial role in modulating apoptotic cell death in the sensitivity to anticancer drugs, and suggest that these proapoptotic genes might interact in the up-regulation for activating downstream signals leading to apoptosis in gastric cancer cells.

Antineoplastic Agents↗
PubMed1999

A phase II trial of low dose administration of 5-fluorouracil and cisplatin in patients with advanced and recurrent gastric cancer.

The clinical efficacy of chemotherapy for patients with advanced gastric cancer has not been established. We investigated in a phase II study the combination chemotherapy of low dose 5-fluorouracil (5-FU) and cisplatin (low dose FP) to evaluate its clinical efficacy in terms of response, quality of life and survival in 43 gastric cancer patients including 29 advanced and 14 recurrent cases. The administration of 5-FU was done by continuous intravenous infusion for 28 consecutive days with a dose of 250 mg/m2, while the administration of cisplatin was done by 1-h intravenous drip-infusion for 5 consecutive days and 2-day intervals per week with a dose of 3.5 mg/m2, that was repeated for 4 weeks in one cycle. The response rate in advanced cases was 48.3%, evaluated in 14 cases of partial response (PR), whereas its response rate in recurrent cases was 35.7%, evaluated in 5 cases of PR. The most effective lesions for low dose FP chemotherapy were primary lesion and lymph node metastasis. The quality of life assessed by performance status and oral intake was improved in 13.8% and 37.9% of advanced cases, and 21.4% and 28.6% of recurrent cases, respectively, as compared to those of pretreatment. The median survival time and 1-year survival rate were 6 months, 21.6% in advanced cases and 10 months, 28.8% in recurrent cases, respectively. The major adverse effect was observed in gastrointestinal toxicity and leukopenia, and the all toxicities were less than grade 2, that were controllable during the treatment. These results indicated that the combination chemotherapy of low dose administration of 5-FU and cisplatin might have therapeutic efficacy in tumor response and offer improvement in quality of life in patients with advanced and recurrent gastric cancer.

Adult↗