Biomedical subjects

C W Kim

Publications and source records attributed to C W Kim.

At least 181 records · Page 10Linked to original sources

PubMed1991

The significance of changing trends in trichinellosis.

Findings during the past two decades have indicated that there are changing trends in trichinellosis in terms of (1) new isolates of Trichinella, (2) new sources of meat, including meat of herbivorous animals and of a greater variety of wild animals, (3) increasing number of cases among new ethnic groups in the USA, and (4) the emergence of new foci in Asia. These changes offer new challenges that warrant our attention. The characterization of each of the new isolates of Trichinella, particularly with respect to its infectivity, has become critical. Since herbivorous animals have been implicated as the source for human infections, thorough cooking of all animal meat is compulsory. Ethnic groups who continue to prepare their food in traditional manner must be informed of the potential danger of trichinellosis and the need for modification in preparation. The emergence of new foci for human trichinellosis emphasizes the importance of direct communication and interaction on a worldwide basis regarding the parasite and the infection.

Animals↗

PubMed1990

Clinical utility of partial flip angle T2-weighted spin-echo imaging of the brain.

To assess the clinical usefulness of partial flip angle (PFA) spin-echo (SE) brain imaging, a total of eighty patients were examined with both conventional double echo T2-weighted SE (2500/30, 80/90 degrees/one excitation) and PFA double echo SE (1200/30, 70/45 degrees/two excitations) on 2.0T system. Two comparative studies were performed: (1) in 65 patients PFA SE technique was compared with conventional SE without flow compensating gradients, and (2) in 15 patients the former was compared with the latter with flow compensating gradients. Imaging time was nearly identical in each sequence. In both studies we found that PFA T2-weighted SE images were almost identical to those obtained with the conventional SE technique in the contrast characteristics and the detection rate of the abnormalities (100%, 85/85 lesions), and more importantly, PFA SE revealed few flow artifacts in the brain stem, temporal lobes and basal ganglia which were frequently seen on conventional SE without flow compensating gradients. Additionally, PFA SE images demonstrated no suppression of CSF flow void in the aqueduct which was commonly seen on conventional SE with flow compensating gradients. In overall image quality, the PFA SE images, particularly the second echo images, were almost comparable with those of conventional SE with flow compensating gradients. A flip angle of 45 degrees seems to be close to Ernst angle, the angle at which maximum signal occurs, for a given TR of 1200 msec for CSF and most of the abnormalities containing higher water content.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1990

Gd-DTPA enhanced MR imaging in intracranial tuberculosis.

Twenty-six patients with intracranial tuberculosis (Tb) (10 with acute meningitis, 5 with chronic meningitis, 5 with meningitic sequelae and 6 with localized tuberculoma(s)) were examined with MR before and after Gd-DTPA enhancement (0.1 mmol/kg), using 2.0T superconducting unit, and the images were retrospectively analyzed and compared with CT scans. Without Gd-DTPA enhancement, the MR images were generally insensitive to detection of active meningeal inflammation and granulomas. The signal intensity of granulomas was usually isointense to gray matter on both T1- and T2-weighted images, whether they were associated with diffuse meningitis or presented as localized tuberculoma(s). A few granulomas showed focal hypointensity on T2-weighted images. Calcifications seen on CT of the meningitic sequelae group usually appeared markedly hypointense on all spin-echo sequences. On Gd-DTPA enhanced T1-weighted images, abnormal meningeal enhancement indicating active inflammation was conspicuous, and the granulomas often appeared as conglomerated ring-enhancing nodules, which seems to be characteristic of granulomas. Thin rim enhancement around the suprasellar calcifications were observed in two out of 5 patients with meningitic sequelae. Compared with CT, MR detected a few more ischemic infarcts, hemorrhagic infarcts, meningeal enhancement and granulomas in the acute meningitis group, but missed small calcifications in the basal cisterns well shown on CT in the sequelae group. Otherwise, MR generally matched CT scans. MR imaging appears to be superior to CT in evaluation of active intracranial Tb only if Gd-DTPA is used, while CT is better than MR in evaluating meningitic sequelae with calcification.

Adolescent↗

PubMed1990

Escherichia coli thymidylate synthase: amino acid substitutions by suppression of amber nonsense mutations.

By using site-directed oligonucleotide mutagenesis, amber nonsense stop codons (5'-TAG-3') have been introduced at 20 sites in the Escherichia coli thymidylate synthase gene. By transforming the thyA mutant plasmids into 13 strains, each of which harbor different amber suppressor tRNAs, we were able to generate over 245 amino acid substitutions in E. coli thymidylate synthase (EC 2.1.1.45). Growth characteristics of these mutants have been studied, yielding a body of information that includes some surprising results in light of the recently published crystal structure of the enzyme.

Amino Acid Sequence↗

PubMed1990

Jejunal leiomyosarcoma detected by Tc-99m sulfur colloid gastrointestinal bleeding scan.

Jejunal leiomyosarcoma was initially detected in a patient by a gastrointestinal bleeding scan with Tc-99m sulfur colloid (SC). The scan showed increased blood flow and delayed persistent accumulation of radiotracer in the tumor. The Tc-99m SC gastrointestinal bleeding scan provided useful information to help determine the differential diagnosis of gastrointestinal tumor with bleeding.

Female↗

PubMed1990

Experimental tissue damage after subcutaneous injection of water soluble contrast media.

Various water soluble contrast media (WSCM) were injected subcutaneously into 970 hind feet of 485 rats. Gross morphologic changes were seen after the injection and analyzed as a function of various physicochemical characteristics of WSCM. The WSCM of larger volume, higher osmolality, higher iodine content, and meglumine salts rather than sodium salts caused more severe tissue damage; younger rats showed more severe tissue damage by WSCM of high osmolality.

Animals↗

PubMed1990

Uterine cervical carcinoma: comparison of CT and MR findings.

Thirty patients with uterine cervical carcinoma underwent computed tomography (CT), magnetic resonance (MR) imaging, and surgical exploration. MR imaging was superior to CT in visualization of the tumor. MR imaging had an accuracy of 77% in the assessment of thickness of cervical stromal invasion. The accuracy rates of these modalities for parametrial evaluation were 78% for clinical evaluation, 70% for CT, and 92% for MR imaging. The overall accuracy rates for tumor staging were 70% for clinical evaluation, 63% for CT, and 83% for MR imaging. MR imaging is superior to clinical evaluation and CT in parametrial evaluation and the staging of uterine cervical carcinoma.

Adult↗

PubMed1990

Hemorrhagic fever with renal syndrome: MR imaging of the kidney.

Magnetic resonance (MR) imaging of the kidneys was performed in 14 patients with a severe form of hemorrhagic fever with renal syndrome (HFRS), a major public health problem in Far Eastern Asia. To the authors' knowledge, this is the first report of renal assessment with MR imaging in HFRS. Three MR imaging studies were done while patients were in the oliguric phase, 19 were done during the diuretic phase, and three were done during the convalescent phase. The authors differentiated the cortex and the medulla in all 21 T1-weighted examinations and all 25 T2-weighted examinations. Seven T1-weighted examinations (33%) and 20 T2-weighted examinations (80%) showed low signal intensity along the outer portion of the medulla, which thus enabled differentiation from the inner medulla. Low signal intensity along the medulla (especially the outer medulla) on T2-weighted images, possibly representing medullary hemorrhage, is fairly constant and characteristic on MR images of the kidneys in patients with HFRS.

Adult↗

PubMed1990

Small hepatocellular carcinoma versus small cavernous hemangioma: differentiation with MR imaging at 2.0 T.

Eighteen small hepatocellular carcinomas (HCCs) and 38 hemangiomas less than 5 cm in diameter were studied with magnetic resonance (MR) imaging at 2.0 T. Relatively T1-weighted spin-echo (SE) 500/30 (repetition time msec/echo time msec) images and proton-density 2,000/30 images showed nonspecific contrast-to-noise ratios (C/Ns) and intensity ratios in HCCs and hemangiomas. On T2-weighted 2,000/60, 90, 120, 150, and 180 images, hemangiomas had significantly greater C/N and intensity ratios than HCCs (P less than .05). The SE 2,000/180 sequence showed the greatest difference in tumor-liver intensity ratios between small HCCs and hemangiomas, followed by the SE 2,000/150 sequence, but there was no statistically significant difference between the two pulse sequences. However, the SE 2,000/180 sequence is limited in the number of sections obtainable for routine clinical liver imaging. The findings indicate that the SE 2,000/60 sequence is optimal for the detection of small HCCs and hemangiomas and that the SE 2,000/150 sequence is optimal for distinguishing small HCCs from hemangiomas at 2.0 T.

Adult↗

PubMed1990

Lobar bronchioloalveolar carcinoma: "angiogram sign" on CT scans.

The authors reviewed computed tomographic (CT) scans of 12 patients with lobar bronchioloalveolar carcinoma. Seven patients had consolidation of the entire lobe, and five patients had segmental consolidation. After contrast material was administered intravenously, the consolidated lung typically appeared on the scan as an area of homogeneous low attenuation, within which were enhanced branching pulmonary vessels (the CT angiogram sign). To evaluate the specificity of this sign in the discrimination of bronchioloalveolar carcinoma, CT scans of 26 patients who had lobar consolidation from other diseases were randomly mixed with the CT scans of 11 patients with bronchioloalveolar carcinoma. Two independent observers who were unfamiliar with the cases classified 10 and nine of the 11 patients with bronchioloalveolar carcinoma, respectively, as positive for bronchioloalveolar carcinoma by applying the CT angiogram sign, and classified as negative 25 and 23 of the 26 patients without bronchioloalveolar carcinoma, respectively, for an overall specificity of 92.3%. The angiogram sign appeared on the CT scan because of the low-attenuating consolidation, which was caused by the production of mucin or other fluid and the intact bronchovascular framework within the tumor.

Adenocarcinoma, Bronchiolo-Alveolar↗

PubMed1990

Gd-DTPA-enhanced MR imaging of the brain in patients with meningitis: comparison with CT.

Plain and Gd-DTPA-enhanced MR images of the brain were obtained in 18 consecutive patients with meningitis (eight with tuberculous, five with bacterial, three with viral, and two with fungal infections); the MR images were compared with CT scans. MR images were obtained on a 2.0-T superconducting unit with both T1- and T2-weighted pulse sequences before injection and with a T1-weighted sequence after injection of Gd-DTPA (0.1 mmol/kg) in all patients. In tuberculous meningitis, MR imaging depicted ischemia/infarct, hemorrhagic infarct of basal ganglia, meningeal enhancement at either basal cistern or convexity surface of brain, and associated small granulomas in a few more patients than CT did. In bacterial meningitis, primary foci of extracranial inflammation (i.e., mastoid, paranasal sinuses) and adjacent intracranial lesions including localized dural inflammation, subdural fluid collection, and/or brain parenchymal lesions were demonstrated much better on MR than on CT. Otherwise, MR images generally matched the CT scan. Although the plain MR images, both T1- and T2-weighted, were the most sensitive in delineating ischemia/infarct, hemorrhage, and edema, they were not as specific as Gd-DTPA-enhanced T1-weighted images and postcontrast CT scans in defining the active inflammatory process of the meninges and focal lesions precisely. We conclude that if Gd-DTPA is used, MR imaging appears to be superior to CT in the evaluation of patients with suspected meningitis. Precontrast MR is needed to delineate ischemia/infarct, edema, and subacute hemorrhage.

Adolescent↗

PubMed1990

Inflammatory pseudotumor of the lung in a child with mycoplasma pneumonia.

A case of inflammatory pseudotumor of the lung occurring in a six-year-old boy is reported with clinicopathologic findings, including its ultrastructure. The patient had had frequent upper respiratory tract infections, and one and half year before the discovery of the lung mass, he suffered from pneumonia of the right lung, which was serologically proven to be a mycoplasma pneumoniae infection. Exploratory thoracotomy revealed a large mediastinal mass that was removed together with the right middle and lower lobes of the lung. The mass arose from the lung with an endobronchial element. Microscopically, the mass was composed of a variety of inflammatory and mesenchymal cells, including plasma cells, histiocytes, lymphocytes, and fibroblast-like spindle cells. Ultrastructurally, the spindle-shaped mesenchymal cells were either fibroblasts or myofibroblasts. At the time of diagnosis of the inflammatory pseudotumor of the lung, the serum titer of antimycoplasma antibody rose again, and the lung parenchyma adjacent to the mass showed interstitial pneumonia with features of bronchiolitis obliterans. The present case suggests that the inflammatory pseudotumor of the lung could be a postinflammatory lesion associated with mycoplasma pneumoniae infection.

Antibodies, Bacterial↗

PubMed1990

[A study of occlusion phase during mastication in complete denture patients].

Author examined the chewing patterns of 10 complete denture wearers with LED mandibular tracking device, and analyzed the average cycle time, average occlusion time and the ratio of average time/average cycle time during chewing occlusion various test foods-standardized carrot and ham, the results were as follow: 1. The average cycle time of chewing carrot was longer than that of chewing ham. 2. The average occlusion time of chewing carrot was longer than that of chewing ham. 3. The ratio of average occlusion time/average cycle time of chewing ham was greater than that of chewing carrot. 4. During chewing carrot or ham, there was an increasing tendency in occlusion time and ratio of occlusion time/cycle time.

Dental Occlusion↗

PubMed1989

Identification of pre-T cells in human peripheral blood. Extrathymic differentiation of CD7+CD3- cells into CD3+ gamma/delta+ or alpha/beta+ T cells.

CD7+CD3- cells purified (greater than 99.99%) by FACS from the peripheral blood of healthy adults include precursors for mature T cells that have the capacity to differentiate into TCR-1+ or TCR-2+ CD3+ cells. Extrathymic differentiation was demonstrable from all eight healthy donors in the presence of a high concentration of IL-2, mitogenic levels of PHA, and irradiated blood mononuclear feeder cells, after a lag of approximately 40 d in vitro. The extrathymic T (ET) cells were predominantly TCR-1+, although TCR-2+ cells were also derived. ET TCR-1+ cells were CD4-CD8-, CD4-CD8DIM+, and CD4+CD8-, and were distinguished from natural T TCR-2+ cells by a variety of cell surface markers. The ET cells had phenotypes generally displayed by normal mature T cells, although the CD5DIM+ on ET cells was more typical of thymocytes. Acquisition of CD3 on purified CD7+CD3- cells was not due to antigenic modulation or growth of contaminants, and ET cells could be demonstrated at the clonal level. Studies in athymic mice and bone marrow recipients support the view that extrathymic maturation does occur in vivo. Whether the CD7+CD3- cell population was unexposed to the thymus, or exposed but not processed, is unknown. In any case, unusual or "forbidden" autoreactive specificities are predicted since ET cells differentiate without thymic selection of the TCR.

Antigens, CD7↗

PubMed1989

Unusual MR manifestations of neurocysticercosis.

MR and CT features of neurocysticercosis are variable and depend fundametally on the stage in evolution of the infection, location, number and size of the worm. The authors retrospectively evaluated MR images obtained on a 2.0T superconducting unit in 22 neurocysticercosis patients and observed various MR features including some new findings. A variety of MR findings are presented with special reference to six case reports. The features include: (1) a large simple cyst containing both internal septations and a scolex; (2) suprasellar racemose cysts mimicking other cysts, (3) a fourth ventricular cyst readily depicted by aid of CSF flow-void in the sagittal plane; (4) degenerating cysts showing "white target" appearance; (5) granulomatous lesions having a "black target" appearance; and (6) a meningitic form showing Gd-DTPA enhancement of basal cisterns and of a subacute infarct.

Adolescent↗

PubMed1989

Sonographic characteristics of small hepatocellular carcinoma.

Fifty-four lesions of small hepatocellular carcinoma under 5 cm in diameter detected by real-time sonography were reviewed to characterize the sonographic feature. Twenty-nine lesions were smaller than 3 cm in diameter and 25 were between 3 and 5 cm in diameter. Sonographic characteristics of hepatocellular carcinoma were peripheral hypoechoic halo (52%), lateral shadow (26%), posterior acoustic enhancement (44%), and mosaic pattern (24%) of the mass. Small tumors less than 3 cm in diameter showed a hypoechoic pattern in half of the cases, whereas most of the tumors between 3 and 5 cm in diameter showed a hyperechoic or mixed pattern. Posterior acoustic enhancement was commonly seen in small tumors less than 3 cm in diameter, while a mosaic pattern was commonly seen in large tumors between 3 and 5 cm in diameter. These results suggest that sonography might be useful for the characterization of small hepatocellular carcinoma.

Adult↗

PubMed1989

Etiology of childhood diarrhea in Korea.

To assess the role of recently recognized enteropathogens in childhood diarrhea in Korea, 231 children with diarrhea admitted to and 104 children without diarrhea seen at the well-baby clinic or the outpatient department of Hanyang University Hospital in Seoul, Korea, were evaluated during a 14-month period. Stools were cultured for bacterial pathogens, including enterotoxigenic (heat-labile and heat-stable enterotoxin-producing) and enteroadherent organisms. Only those stools obtained from patients with diarrhea were examined for rotavirus. All Escherichia coli isolates were screened for Shiga-like toxin (SLT) I, SLT-II, enterohemorrhagic E. coli fimbriae, and enteroinvasiveness by colony hybridization. One or more pathogens were identified in 75.8% of the children with diarrhea. Rotavirus was the most frequently identified pathogen, accounting for 47% of the cases. Other major enteropathogens were enterotoxigenic E. coli (22%), Clostridium difficile (16%), enteroadherent E. coli (15%), and enteropathogenic E. coli (6%). Shigella spp., Campylobacter jejuni, Salmonella spp., SLT-I-and enterohemorrhagic-E. coli-fimbria-probe-positive E. coli serotype O26:H11 and enteroinvasive E. coli were isolated from only a few patients. Aeromonas hydrophila and E. coli O157 were not isolated. Compared with those of the controls, the isolation rates of heat-stable-enterotoxin-producing E. coli (P less than 0.05), C. difficile (P less than 0.025), and enteroadherent E. coli (P less than 0.05) were significantly higher in the patients with diarrhea. The greatest number of rotavirus, enterotoxigenic E. coli, and C. difficile cases were identified during the cool, dry months of October and November.

Adolescent↗

PubMed1989

Biliary cystadenoma and cystadenocarcinoma: CT and sonographic findings.

Eight women (ages 18-65 years; mean, 47 years) with biliary cystadenoma (n = 3) or cystadenocarcinoma (n = 5) were examined with computed tomography and sonography. The appearance of the tumors varied from unilocular cystic masses to multilocular cystic masses with multiple satellite tumors, although the majority (n = 6) of tumors were single, multilocular, and cystic. Cystic areas showed attenuation numbers under +30 HU. Papillary excrescences, nodular thickening of internal septa, and mural nodules, which showed contrast enhancement, were seen in one case of cystadenoma and all five cases of cystadenocarcinoma. One cystadenoma and one cystadenocarcinoma contained calcifications. Three cases showed connection to the intrahepatic bile ducts. Biliary cystadenoma and cystadenocarcinoma should be the primary diagnostic consideration when one detects in a middle-aged woman a well-encapsulated, multilocular cystic mass connected to the biliary system or prolapsing into the bile duct.

Adult↗