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Biomedical subjects

C K Kim

Publications and source records attributed to C K Kim.

At least 163 records · Page 9Linked to original sources
PubMed1997

Object-recognition and spatial learning and memory in rats prenatally exposed to ethanol.

Prenatal ethanol exposure can produce cognitive and behavioral impairments. In the present study, rats from prenatal ethanol (E), pair-fed (PF), and ad libitum-fed control (C) treatment conditions were tested on the object-recognition delayed-nonmatching-to-sample (DNMS) task with nonrecurring items and on the spatial-navigation Morris water maze task. In Experiment 1, there were no significant differences among groups in object-recognition learning and memory, distractibility, or response perseveration on the DNMS task. In Experiment 2, the same rats were tested in the water maze; E rats took significantly longer to learn the task than did the PF or C rats. These data suggest that the mechanisms underlying spatial cognitive abilities are more vulnerable to the teratogenic effects of prenatal ethanol exposure than those underlying object-recognition abilities.

Animals↗
PubMed1997

Influence of carrying book bags on gait cycle and posture of youths.

The purpose of this investigation was to determine the impact of different methods of carrying book bags on static posture and gait kinematics of youths aged 11-13 years. Surveys identified group descriptive characteristics of subjects and book bags. Ten subjects representing the best composite of the mean characteristics of this population were filmed for both static posture and dynamic conditions of one stride length. Subjects participated in four conditions: without bag (WO), one-strap backpack (1BP), two-strap backpack (2BP), and one-strap athletic bag (ATH). Lateral spinal deviation was not significantly different between 2BP and WO. However, differences (+/-SE) were observed between 1BP (8.5 +/- 0.7 degrees) and ATH (8.3 +/- 2.4 degrees) as compared with WO (1.9 +/- 0.5 degrees). Shoulder elevation from a horizontal position showed no difference between WO and 2BP. Without bag (2.0 +/- 0.9 degrees) was different from 1BP (17.6 +/- 1.8 degrees) and ATH (15.6 +/- 2.1 degrees). 1BP was also different from 2BP (3.4 +/- 1.1 degrees). Bag carrying significantly decreased stride length (1.59 +/- 0.04 m) and increased stride frequency (57.36 +/- 1.6 cycles/min) compared to WO (1.72 +/- 0.06 m; 54.64 +/- 1.2 cycles/min, respectively), thereby reducing the support phase of the gait. One-strap bags (1BP, ATH) promoted lateral spinal bending and shoulder elevation, while the two-strap backpack significantly reduced these book bag carrying stresses. ATH promoted greater angular motion of the head and trunk as compared to backpack book bags. Carrying a backpack (1BP, 2BP) promoted significant forward lean of head and trunk compared to ATH or WO. In conclusion, the daily physical stresses associated with carrying book bags on one shoulder (1BP, ATH) significantly alters the posture and gait of youth.

Adolescent↗
PubMed1997

Conversion of non-iodine-concentrating differentiated thyroid carcinoma metastases into iodine-concentrating foci after anticancer chemotherapy.

We present the unusual case of a 29-year-old man diagnosed in 1975 with papillary carcinoma of the thyroid metastatic to regional lymph nodes. The patient underwent surgical resection, postoperative iodine-131 (131I) radioablation and levothyroxine suppression. He was subsequently lost to follow-up. In 1991, he presented with extensive metastatic disease that was not demonstrable on whole-body 131I imaging, but was seen on computerized tomography and whole-body thallium chloride scanning. The patient was treated with cisplatin (Platinol) and doxorubicin (Adriamycin). Repeat 131I imaging after three cycles of chemotherapy showed significant 131I uptake in previously non-iodine-concentrating lesions. The patient was subsequently treated with 200 mCi 131I. We postulate this patient's non-iodine-concentrating thyroid cancer may have become functional by either a differentiating effect of chemotherapy on the tumor cells, or perhaps a selective cytotoxicity against nonfunctional, less differentiated papillary thyroid cancer cells, or both. This would allow more functional differentiated cells to overgrow and become the predominant cell type in the lesions. Chemotherapy may be beneficial in patients with advanced non-iodine-concentrating differentiated thyroid carcinoma by inducing radioiodine uptake and allowing subsequent radioiodine therapy. The possible mechanisms of induction of iodine uptake by chemotherapy are discussed.

Adult↗
PubMed1997

The 'mouse face' appearance of the vertebrae in Paget's disease.

Paget's disease is occasionally found as an incidental finding on bone scans performed for the evaluation of metastatic disease, which causes a diagnostic and a subsequent therapeutic dilemma. We have previously described the "Mouse Face" appearance of vertebrae on bone scans (increased uptake in the vertebral body, posterior elements, and the spinous process), which was fairly specific for Paget's disease in a small series. This retrospective study was undertaken to determine if this observation holds true in a larger series. Bone scans performed in 2,881 patients were randomly selected, and were reviewed by 2 physicians. Thirty-nine cases with a "Mouse Face" appearance were identified. Diagnosis was established in 30 of the 39 patients by correlative radiographic studies and/or clinical follow-up. Twenty patients were referred for the evaluation of possible metastases, and 7 were found to have metastases at the sites of "Mouse Face". The other 13 had Paget's disease. However, 6 of the 7 patients with metastases had extravertebral findings compatible with multiple metastases, and the remaining patient had a "Mouse Face" lesion only, with a question of metastases. Ten patients were evaluated for Paget's disease or others, and none of them had metastases at the site of the "Mouse Face". The "Mouse Face" appearance is more suggestive of Paget's disease than metastases even in patients with cancer. These patients should be assumed unlikely to have vertebral metastases, unless proven by another correlative radiologic study.

Adult↗
PubMed1997

Sarcomatous transformation of neurofibromas. Comparative imaging with Ga-67, Tl-201, Tc-99m pentavalent DMSA and Tc-99m MIBI.

A 29-year-old man, with a history of von Recklinghausen's disease, presented with progressive dyspnea associated with a rapidly growing mass on the right chest wall. Plain radiograph and CT of the chest revealed a huge soft-tissue mass with central low-density area involving the right upper lung and chest wall. SPECT imaging with Ga-67 citrate, Tl-201 chloride, Tc-99m pentavalent DMSA (V-DMSA), and Tc-99m MIBI were performed to characterize the mass. The tumor concentrated Ga-67, Tl-201, and Tc-99m (V) DMSA, but not Tc-99m MIBI. Punch biopsy of the lesion revealed malignant transformation of a thoracic neuroma (neurofibrosarcoma). Subsequently, findings compatible with the presence of a multidrug resistance-1 (MDR1) gene in the tumor was documented, which may explain the poor uptake of Tc-99m MIBI. The patient did not respond to intensive chemotherapeutic regimens, and died 3 months later. This case demonstrates the potential use of combined radionuclide imaging for the detection of malignant transformation of neurofibroma, as well as for predicting tumor response to chemotherapy.

Adult↗
PubMed1997

Retrospective analysis of factors related to clinical outcome of guided tissue regeneration procedures in intrabony defects.

The purpose of this retrospective study was to determine factors affecting clinical outcome of guided tissue regeneration (GTR) in the treatment of intrabony periodontal defects. 38 patients each contributing 1 isolated intrabony defect treated with GTR were included in this analysis. Patient and defect characteristics, and defect-specific recordings relative to clinical outcome 6 months postsurgery were assessed. GTR treatment resulted in clinically and statistically significant improved probing depths (PD), clinical attachment levels (CAL), and probing bone levels (PBL). Presurgery PD and PBL were of predictive value for CAL gain and PBL gain, respectively. CAL and PBL gain did not correlate to defect depth or configuration. Cigarette smoking exhibited a highly significant negative correlation to parameters of clinical outcome.

Adult↗
PubMed1997

Pharmacologic intervention for the diagnosis of acute cholecystitis: cholecystokinin pretreatment or morphine, or both?

Recent data and reanalysis of the literature suggest that nonvisualization of the gallbladder on the delayed images of cholescintigraphy is a nonspecific finding. Morphine augmentation has a reasonably good, though imperfect, specificity and positive predictive value, that are significantly better than for delayed imaging, in addition to its logistical advantage (shortening the imaging time). The technique is recommended, therefore, for routine clinical use in patients with nonvisualization of the gallbladder at 1 hr. Further study seems to be necessary to assess the effect of variable or no visible effect of low-dose morphine among patients on the efficacy of morphine-augmented cholescintigraphy. Sincalide pretreatment, when administered at the physiologic rate, is helpful in conditions in which functional resistance to tracer flow into the gallbladder are present. The results from the series by Chen et al. and by Kim et al. suggest that morphine augmentation can further improve the efficacy of the test even after CCK pretreatment. A comparison between the efficacy of delayed imaging and that of imaging for 60-90 min after CCK pretreatment is not available. Therefore, the latter does not obviate the need for delayed imaging when the morphine augmentation technique is not used. Finally, the nuclear medicine physician should use the most optimal technique for the pharmacologic intervention, in other words, the dose and the rate of administration. Certain conditions and medications may affect gallbladder contraction. It is also important to be aware of the various physiologic and pharmacologic effects on imaging findings, not only those findings that are normal but also the undesirable variants. Failure to recognize such effects can lead to incorrect interpretations.

Acute Disease↗
PubMed1997

Scintigraphic monitoring of reticuloendothelial system in patients with type 1 Gaucher disease on enzyme replacement therapy.

UNLABELLED: The purpose of this study was to define the scintigraphic pattern of marrow replacement and changes in reticuloendothelial activity after enzyme replacement therapy in patients with Gaucher disease. METHODS: Forty patients underwent baseline whole-body imaging with 99mTc-sulfur colloid and evaluation of liver and spleen volume with CT or magnetic resonance imaging. Thirty-seven of the 40 patients were treated with enzyme replacement. Therapeutic responses of central and peripheral bone marrow and the changes in pulmonary uptake of 99mTc-sulfur colloid were assessed visually at 1-4 yr after the start of therapy. Changes in liver and spleen volumes were analyzed quantitatively. The initial pattern of marrow involvement was correlated with disease severity (based on baseline blood counts and liver and spleen volumes). RESULTS: Baseline studies revealed that 38 of 40 (95%) and 28 of 40 (70%) of the patients in this study had abnormal peripheral and central marrow activity, respectively. Twenty of 24 evaluable patients (83.3%) on therapy showed regression of peripheral bone marrow activity to a more proximal location in the lower extremities, increased ratio of pelvic/proximal femoral activity to distal activity or both. Fourteen of 19 treated patients (73.7%) with abnormal initial central marrow activity showed detectable improvement in central bone marrow activity as a result of therapy. In patients with initial lung uptake of 99mTc-sulfur colloid, 91% showed complete resolution of the uptake after therapy. These changes in colloid uptake and distribution were associated with significant reductions in liver and spleen volumes and improvements in blood counts. CONCLUSION: Most patients with Gaucher disease demonstrate increased central bone marrow activity and regression of activity in peripheral bone marrow with enzyme replacement therapy. Additionally, the abnormal phagocytic pulmonary activity observed before therapy in many of the patients resolves.

Adult↗
PubMed1997

The effect of cold stress on lymphocyte proliferation in fetal ethanol-exposed rats.

Prenatal ethanol exposure and stress have each been shown to have significant effects on the immune system. This study examined the possible interactive effects of prenatal ethanol exposure and exposure to stress later in life on the immune system. Differential vulnerability to these challenges in female and male offspring was assessed. At 5 to 6 months of age, female and male offspring from prenatal ethanol-exposed (E), pair-red (PF), and ad libitum-fed control (C) conditions were exposed to 0, 1 or 3 days of cold (4 degrees C). At the end of the cold period, the proliferative response of splenic lymphocytes to the mitogens concanavalin A (Con A) and pokeweed mitogen (PWM) was assessed. The data demonstrate a significant interactive effect between prenatal ethanol exposure and cold stress in female offspring. After 1 day of cold stress, E females had significantly increased PWM-induced lymphocyte proliferation compared with PF and C females, and significantly increased Con A-induced lymphocyte proliferation compared with PF females. There were no differences in PWM or Con A-induced lymphocyte proliferation among E, PF, and C females after 0 or 3 days of cold stress, nor among E, PF, and C males on any test day. Regardless of prenatal treatment, females exposed to 1 or 3 days of cold had significantly greater basal plasma corticosterone levels than females not exposed to cold. In contrast, only E males exposed to 1 or 3 days of cold had significantly increased basal plasma corticosterone levels, compared with E males not exposed to cold; PF and C males showed no significant change in basal corticosterone after cold stress. These data demonstrate that, in response to the challenge of cold stress, changes in lymphocyte proliferation to PWM and Con A may occur selectively in E females. Moreover, the interactive effects of prenatal ethanol and cold stress may result in enhanced rather than suppressed immune responsiveness.

Acclimatization↗
PubMed1996

Structure of the pcbC gene encoding 2,3-dihydroxybiphenyl dioxygenase of Pseudomonas sp. P20.

Pseudomonas sp. P20 is a soil bacterium growing in biphenyl or 4-chlorobiphenyl as the sole carbon and energy source, where the initial catabolism of biphenyl to form benzoate is catalyzed by four enzymes encoded in the pcbABCD gene cluster. The nucleotide sequence of the 2,3-dihydroxybiphenyl dioxygenase gene corresponding to the pcbC gene was determined. The pcbC gene was composed of 921 base pairs with an ATG initiation codon and a TGA termination codon, which can encode a polypeptide of molecular mass 34 kDa containing 306 amino acids. A promoter-like sequence and ribosome-binding sequence were identified upstream of the initiation codon. The deduced amino acid sequence of 2,3-dihydroxybiphenyl dioxygenase exhibited 47% identity with that of corresponding enzyme of Pseudomonas sp. DJ-12, and less than 35% identity with those of other extradiol-type dioxygenases.

Amino Acid Sequence↗
PubMed1996

Characterization of the gene encoding catechol 2,3-dioxygenase of Alcaligenes sp. KF711: overexpression, enzyme purification, and nucleotide sequencing.

Catechol 2,3-dioxygenase (C23O) is an extradiol-type dioxygenase that catalyzes the aromatic ring fission of catechol to form 2-hydroxymuconic semialdehyde. The C23O gene of Alcaligenes sp. KF711 was overexpressed in Escherichia coli HB101 by using the lac promoter of pUC18, and its gene product was purified by using immunoaffinity chromatography. The purified C23O exhibited a 35-kDa single band on an SDS-polyacrylamide gel, and its ring-fission activity on dihydroxylated aromatics was 4-methylcatechol > 4-chlorocatechol > catechol > 3-methylcatechol >> 2,3-dihydroxybiphenyl. Nucleotide sequence analysis of the C23O gene revealed an open reading frame of 927 bp, which can encode a polypeptide of 308 amino acid residues. The predicted molecular mass of 35 kDa is in agreement with that of purified C23O on an SDS-polyacrylamide gel. The amino acid sequence of the C23O was compared with those of nine other extradiol-type dioxygenases, including 2,3-dihydroxybiphenyl dioxygenase (2,3-DHBD) and 1,2-dihydroxynaphthalene dioxygenase (1,2-DHND). The C23O of Alcaligenes sp. KF711 exhibited 80 to 94% identity in amino acid sequence with other C23Os, and 20 to 25% identity with 1,2-DHND and 2,3-DHBDs. Furthermore, sequence comparison of 10 extradiol-type dioxygenases has led to identifying 19 evolutionarily conserved amino acid residues whose possible catalytic roles are proposed.

Alcaligenes↗
PubMed1996

Structure of catechol 2,3-dioxygenase gene encoded in chromosomal DNA of Pseudomonas putida KF715.

A catechol 2,3-dioxygenase gene in chromosomal DNA of P. putida KF715 was cloned and its nucleotide sequence analyzed. The enzyme gene was composed of 924 base pairs with ATG initiation codon and TGA termination codon, which can encode a polypeptide of molecular weight 35 kDa containing 307 amino acids. A promoter-like sequence and a ribosome-binding sequence were identified upstream the enzyme gene. A deduced amino acid sequence of the catechol 2,3-dioxygenase exhibited 94% identity with that of corresponding enzyme in TOL plasmid and 25% identity with that of 2,3-dihydroxybiphenyl 1,2-dioxygenase from the same strain. Furthermore, sequence comparison of the catechol 2,3-dioxygenase with other extradiol-type dioxygenases has led to identify evolutionally conserved amino acid residues whose possible catalytic roles are proposed.

Amino Acid Sequence↗
PubMed1996

Variable bile retention on cholescintigraphy after morphine administration.

Intravenous morphine sulfate has been used in conjunction with cholescintigraphy. We studied the variations in the degree and duration of the effects of 2 mg morphine on biliary kinetics in patients with gallbladder nonvisualization and undertook a comparison with biliary kinetics in patients not given morphine. Of 24 morphine-augmented cholescintigrams that were obtained without additional injection of technetium-99m diisopropyl-iminodiacetic acid (DISIDA), 19 showed continued gallbladder nonvisualization. Time-activity curves (TACs) of the liver parenchyma and common bile/hepatic duct (CD) of the entire study (before and after morphine) were obtained. In two patients, the CD was not sufficiently visualized to define a region of interest. In 17 patients, the peak CD activity was observed between 14 and 47 min after injection of 99mTc-DISIDA. In these 17, the TAC of the CD was declining essentially in parallel with the TAC of the liver parenchyma at the end of the first hour before morphine. After morphine injection, CD activity slowly increased for a variable duration in nine patients, while it continued to decrease in eight. CD activity between 1 h and 2 h showed a continuously decreasing pattern in another group of 20 patients who did not receive morphine despite gallbladder nonvisualization at 1 h. In summary, no significant effect of 2 mg of intravenous morphine on biliary kinetics was detected scintigraphically in a considerable proportion of patients. Also, there was considerable variation in the duration of the effect of morphine, when such an effect was present. This observation may have significant clinical implications for morphine-augmented cholescintigraphy.

Bile↗
PubMed1996

Fetal ethanol exposure alters pituitary-adrenal sensitivity to dexamethasone suppression.

The present study investigated the hypothesis that a deficit in feedback inhibition of the hypothalamic-pituitary-adrenal (HPA) axis may underlie the hormonal hyperresponsiveness seen in fetal ethanol-exposed rats. Male and female Sprague-Dawley rats from prenatal ethanol (E), pair-fed (PF) and ad lib-fed control (C) treatment groups were tested in adulthood. The effects of dexamethasone (DEX) blockade on basal and stress corticosterone (CORT) levels and stress adrenocorticotropin (ACTH) levels were examined over a 36-h period. Stress CORT and ACTH levels after DEX administration at the trough (AM) and peak (PM) of the CORT circadian rhythm were compared. DEX administration significantly suppressed both resting and stress levels of CORT and ACTH in all animals, regardless of prenatal treatment. Importantly, E animals did not differ from PF and C animals in basal CORT. However, E males and females had significantly higher stress levels of CORT and/or ACTH than PF and C animals, and further, showed differential responsiveness following DEX administration depending on the time of day when testing occurred. At the trough of the CORT circadian rhythm. E males did not differ from PF and C males, whereas E females had increased stress levels of CORT compared to PF and C females. In contrast, at the peak of the circadian rhythm, E males showed increased stress levels of CORT but not ACTH, whereas E females showed increased stress levels of both CORT and ACTH compared to males and females in respective control groups. These data support the hypothesis that E animals may exhibit deficits in HPA feedback inhibition compared to controls and suggest a sex-specific difference in sensitivity of the mechanism underlying HPA hyperresponsiveness.

Adrenocorticotropic Hormone↗
PubMed1996

Dependency of standardized uptake values of fluorine-18 fluorodeoxyglucose on body size: comparison of body surface area correction and lean body mass correction.

In an attempt to minimize dependency of conventional standardized uptake values (SUVs) of F-18-fluorodeoxyglucose (FDG) normalized for the total body weight (TBW) on patient's body weight, the uses of SUV corrected for the lean body mass (LBM) and that corrected for the body surface area (BSA) have been proposed as alternatives. We compared the dependency of SUVLBM and SUVBSA on the overall body size. FDG-PET images were acquired on 44 patients. SUVLBM and SUVBSA for the liver were determined as previously described. Following normalization of the scales of the values obtained from these two approaches, the mean +/- S.D. was 2.86 +/- 0.52 (SUVLBM) and 2.86 +/- 0.50 (SUVBSA). A linear regression analysis was performed for correlating the liver SUVLBM and SUVBSA, with each of TBW, LBM, BSA and height. The dependency of the two values on TBW was similar. SUVLBM showed a moderate dependency on height (r = 0.56, P = 0.00007), LBM (r = 0.55, P = 0.0001) and BSA (r = 0.51, P = 0.0004), whereas SUVBSA showed no dependency on LBM (r = 0.18, P = 0.24) or height (r = 0.20, P = 0.19), and a minimal dependency on BSA (r = 0.38, P = 0.01). In conclusion, SUVBSA appears to be less dependent on overall body size, particularly height and lean body mass, than SUVLBM.

Abdominal Neoplasms↗