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Biomedical subjects

T Kim

Publications and source records attributed to T Kim.

At least 109 records · Page 6Linked to original sources
PubMed1999

Evaluation of regional liver function by gadolinium-EOB-DTPA-enhanced MR imaging.

We evaluated the role of magnetic resonance (MR) imaging with gadolinium-ethoxybenzyl-diethylenetriamine-pentaacetic acid (Gd-EOB-DTPA), in estimating regional liver function in a rat ischemia-reperfusion model. Ischemic liver damage was induced in the right lobe by vascular clamping for 0 (sham), 30 (I-30), 60 (I-60), and 90 min (I-90 group). The ischemic lobes in the I-60 and I-90 groups was clearly visualized as a high intensity area in the T1 images at late phase of Gd-EOB-DTPA enhancement, Moreover, the T1/2 of signal intensity in ischemic lobes significantly correlated with the duration of vascular clamping. We also observed significant correlation between T1/2 and ATP concentration in the liver tissue (r = -0.719, P = 0.04). Our results indicate that MR imaging with Gd-EOB-DTPA is useful for evaluation of regional liver function in rats.

Animals↗
PubMed1999

Pancreatic CT imaging: effects of different injection rates and doses of contrast material.

PURPOSE: To assess the effects of the intravenous injection rate and dose of contrast material on pancreatic computed tomography (CT). MATERIALS AND METHODS: A total of 126 patients were divided at random into four groups with different injection rates and doses. Groups 1 and 2 underwent injection of 2 mL per kilogram of body weight of 300 mg of iodine per milliliter of contrast material, and groups 3 and 4 underwent injection of 1.5 mL/kg. The injection rate was 5 mL/sec for groups 1 and 3 and 3 mL/sec for groups 2 and 4. Single-level serial CT scanning was performed at the level of the pancreatic head, and the pancreatic enhancement value was calculated. RESULTS: The maximum pancreatic enhancement value was 99 HU +/- 18 (mean +/- SD) for group 1, 90 HU +/- 18 for group 2, 86 HU +/- 15 for group 3, and 74 HU +/- 13 for group 4. There were significant differences in the maximum pancreatic enhancement value between groups 1 and 2 (P = .045), between groups 3 and 4 (P = .001), between groups 1 and 3 (P = .016), and between groups 2 and 4 (P = .001). CONCLUSION: Both a higher dose and a faster injection rate increased the maximum pancreatic enhancement value.

Adult↗
PubMed1999

Laryngopharyngeal sensory discrimination testing and the laryngeal adductor reflex.

Laryngopharyngeal sensory capacity has been determined by endoscopically administering air pulse stimuli to the mucosa innervated by the superior laryngeal nerve and asking the patient if he or she feels the stimulus. A potential shortcoming of this psychophysical testing (PT) procedure is that it is a subjective test, and patients with impaired cognition may not be able to perform the required task. In the search for an objective measure of laryngeal sensory function, we have observed that the laryngeal adductor reflex (LAR) is evoked at stimulus intensities similar to those capable of eliciting the psychophysical, or perceptual, response. The purpose of this study is to determine if the threshold for eliciting the LAR is the same as that of the sensory threshold. A specially designed endoscope was used to present air pulse stimuli (range 0.0 to 10 mm Hg) to the laryngopharynx in 20 healthy subjects and in 80 patients with dysphagia, using both PT and the LAR. The patients had a variety of underlying diagnoses, with stroke and chronic neurologic disease predominating (n = 65). In the control group and in the group of patients with dysphagia, there was no statistically significant difference between the median laryngopharyngeal sensory thresholds whether we used PT or the LAR (p>.05, Wilcoxon signed-rank test). The intraclass correlation for the total sample was .999 (U = .999, L = .998). Since psychophysical and sensorimotor reflex thresholds were not statistically significantly different and the intraclass correlation was close to a perfect correlation, we conclude that the LAR can be used as an objective and accurate clinical method of endoscopically assessing laryngopharyngeal sensory capacity.

Deglutition Disorders↗
PubMed1999

Diffusion-weighted single-shot echoplanar MR imaging for liver disease.

OBJECTIVE: The aims of this study were to determine apparent diffusion coefficients (ADCs) of the abdominal organs and liver lesions, to determine the effect of the magnitude of b values on the ADCs, and to determine whether measured ADCs of liver tumors help differentiate benign from malignant lesions. SUBJECTS AND METHODS: Six healthy volunteers and 126 patients were examined with diffusion-weighted single-shot echo-planar imaging using multiple b values (maximum, 846 sec/mm2). The ADCs of the liver, spleen, kidney, 49 malignant liver lesions (33 hepatocellular carcinomas, 15 metastatic liver tumors, and one cholangiocellular carcinoma), and 30 benign lesions (17 cysts, 12 hemangiomas, and one angiomyolipoma) were calculated. RESULTS: The ADCs of the abdominal organs and liver lesions showed smaller values when calculated with the greater maximum b values. The ADCs of the benign lesions calculated with all the b values of less than 850 sec/mm2 (2.49+/-1.39 x 10(-3) mm2/sec) were significantly (p = .0024) greater than those of the malignant lesions (1.01+/-0.38 x 10(-3) mm2/sec). When the maximum b value is 846 sec/mm2, use of a threshold ADC of 1.6 x 10(-3) mm2/sec would result in a sensitivity of 98% and a specificity of 80% for differentiation of malignant liver lesions from benign lesions. CONCLUSION: Measurement of ADC has good potential for characterizing liver lesions, but the calculated ADCs could be affected by the magnitude of the maximum b value.

Adult↗
PubMed1998

Molecular cloning, characterization, and expression of the chicken heme oxygenase-1 gene in transfected primary cultures of chick embryo liver cells.

Using chick heme oxygenase-1 (cHO-1) cDNA as a probe, three independent clones were identified from screening a lambda FixII chick genomic library. Genomic Southern blots using this cDNA probe or a cHO-1 5' specific probe showed that cHO-1 is a single-copy gene. Based on restriction enzyme analysis, Southern blots, polymerase chain reaction analysis and DNA sequencing, it was confirmed that the three overlapping clones isolated cover the entire cHO-1 gene, as well as approximately 10 kb of the flanking regions on both ends. As with mammalian HO-1x, cHO-1 has five exons and four introns. Computer analysis of the DNA sequence obtained identified consensus sequences corresponding to numerous transcription factor recognition elements. These include AP-1, AP-2, NF-kB, C/EBP, c-Myc and a metal-responding element identified in the promoter region, and two Sp-1 elements in intron 1. Transient expression studies in transfected primary cultures of chick embryo liver cells showed that a CAT reporter gene construct containing 2.8 kb of the cHO-1 promoter region responded to sodium arsenite, H2O2, transition metals and 12-0-tetradecanoylphorbol 13-acetate, but not to heme. Studies with deletion mutants, consisting of various lengths of the cHO-1 promoter region, indicated that there are two regions important for sodium arsenite induction, one located between residues -1642 and -1293, and the second located in the first 263 base pairs of the cHO-1 promoter. DNA binding studies by electrophoretic mobility shift assay showed that nuclear protein isolated from primary cultures of chick embryo liver cells bound to the oligonucleotide probe containing an AP-1 element identified at -1573 to -1580. In addition, such binding was increased by cobalt or sodium arsenite treatment.

Animals↗
PubMed1998

Effects of L-arginine on the systemic, mesenteric, and hepatic circulation in patients with cirrhosis.

Nitric oxide (NO) is known to play an important role in modulating both the hepatic and mesenteric circulation under physiological and pathological conditions. We investigated how L-arginine, a precursor of NO, modifies the hepatic and mesenteric circulation in patients with cirrhosis. The study design was a single-blind controlled study. We measured the systemic and portal hemodynamics before and following intravenous L-arginine and saline infusion using pulsed Doppler ultrasonography in 20 patients with cirrhosis, and then the effects were compared with those found in 20 healthy subjects. In these patients, the effects of L-arginine on hepatic circulation were investigated using hepatic catheterization. L-Arginine infusion induced systemic vasodilation in both the healthy controls and the cirrhotic patients in a similar hemodynamic manner. In these patients, the L-arginine-induced increase in the portal flow was significantly higher than that of cardiac output (CO); however, the relation was the inverse in healthy subjects. Moreover, the L-arginine-induced increase in the portal flow was greater in the cirrhotic patients than that seen in healthy subjects. As a result, L-arginine infusion was thus found to selectively augment the hepatopetal portal blood flow in the cirrhotic liver. In patients, L-arginine infusion induced marked hepatic vasodilation as demonstrated by the reduced hepatic sinusoidal resistance (HSR) and increased estimated hepatic blood flow (EHBF) associated with the ameliorated intrinsic clearance of indocyanine green. Despite the fall in HSR, the hepatic venous pressure gradient (HVPG) increased following L-arginine infusion. The mesenteric and hepatic vascular areas of cirrhosis exhibited an increased susceptibility to the dilator action of L-arginine. These findings suggest that the enhanced NO production in the splanchnic vascular area has an important role in the hepatic circulation in patients with cirrhosis.

Aged↗
PubMed1998

Parasites influence social rank and morphology, but not mate choice, in female red junglefowl, Gallus gallus.

Parasites can profoundly affect host morphology and behaviour, but previous work has focused on the effects of parasites on males. In the present study, we assessed the effects of infection with the nematode Ascaridia galli on the morphology and behaviour, including mate choice, of female red junglefowl. Hens infected with A. galli had lower mass and smaller combs than unparasitized birds when sexually mature. Parasite status had a significant effect on social rank in all-female flocks, with high-ranking birds being less likely to be parasitized. Larger females had higher social rank, but comb size was unrelated to social status. Neither parasite status nor social rank had any effect on mate choice. These results differ from those found for male red junglefowl, and suggest that males and females may allocate resources differently to comb versus growth. The low cost of choice in the red junglefowl mating system may also contribute to the lack of an effect of parasites and social status on mate choice Copyright 1998 The Association for the Study of Animal Behaviour

Journal Article↗
PubMed1998

Fiberoptic endoscopic evaluation of swallowing with sensory testing (FEESST) in healthy controls.

The purpose of this study was to introduce a new method of bedside assessment of both the motor and sensory components of swallowing called fiberoptic endoscopic evaluation of swallowing with sensory testing (FEESST). This approach combines the established bedside endoscopic swallowing evaluation with a more recently described technique that allows objective determination of laryngopharyngeal (LP) sensory discrimination thresholds by delivering air pulse stimuli to the mucosa innervated by the superior laryngeal nerve via a flexible endoscope. A prospective study was conducted of FEESST in 20 healthy control subjects, mean age of 34 +/- 11 years. LP sensory thresholds were defined as either normal (< 4.0 mmHg air pulse pressure [APP]), moderate deficit (4.0-6.0 mmHg APP), or severe deficits (> 6.0 mmHg APP). Subsequent to LP sensory testing, food of varying consistencies, mixed with green food coloring, was given and attention was paid to spillage, laryngeal penetration, pharyngeal residue, aspiration, and reflux. Therapeutic maneuvers such as postural changes and airway protection techniques were performed on each subject to determine if the assessed swallowing parameters were affected by maneuvers. All patients completed the study; all had normal LP sensory discrimination thresholds (2.9 +/- 0.7 mmHg APP). There were no instances of spillage, laryngeal penetration, or aspiration. Two of 20 subjects had pharyngeal residue and 2 of 20 had reflux. Institution of therapeutic maneuvers resulted in a predictable change in the endoscopic view of the laryngopharyngeal anatomy. FEESST provides comprehensive, objective sensory and motor information about deglutition in the bedside setting and might have implications for the bedside diagnosis and management of patients with dysphagia.

Adult↗
PubMed1998

Immunohistochemical demonstration of lymphatic vessels in human dental pulp.

The existence of lymphatic vessels in dental pulp has been a matter of continuing controversy because of the difficulty of discriminating them in ordinary stained tissue sections. Recently, we have succeeded in establishing a new identification method for lymphatic vessels in human frozen sections by using a commercial monoclonal antibody specific for the human thoracic duct and anti-human laminin antiserum. The present study aimed to examine the lymphatic vessels in human dental pulp using the new immunostaining method, and compared the results with those in human small intestine. The study clearly demonstrated the distribution of lymphatic vessels in human dental pulp. Large lymphatic vessels are located in the central part of the pulp and there are small lymphatic vessels in the periphery of the pulp. This suggests that lymphatic drainage of the human dental pulp starts from the periphery of the pulp and collects in the central part of the pulp. A notable difference between the small intestine and dental pulp was found in the immunoreactivity of lymphatic vessels to anti-human laminin anti-serum. In small intestine, immunoreactivity was significantly weaker than that of the blood vessels, whereas in dental pulp, that of lymphatic vessels was almost the same as blood vessels, except for some lymphatic vessels showing very weak reactivity. These findings suggest that the development of the basement membrane in both the lymphatic and blood vessels of human dental pulp is not as marked as in other tissue.

Adolescent↗
PubMed1998

Lymphatic endothelium expresses PECAM-1.

The expression of adhesion molecules on the lymphatic endothelium of human small intestine and submandibular lymph node was studied immunohistochemically with the antibodies for selectin family and Ig superfamily members. In both small intestine and submandibular lymph node, lymphatic endothelium did not express intercellular adhesion molecule-1 and endothelial cell-selectin but expressed platelet-endothelial cell adhesion molecule-1 (PECAM-1). Though lymphatic vessels may not have a positive function in leukocyte rolling and adhesion, lymphatic endothelium may interact with leukocytes, with PECAM-1 playing a role.

Aged↗
PubMed1998

The effects of intraocular lidocaine on the corneal endothelium.

OBJECTIVE: The study aimed to evaluate the direct effect of intraocular lidocaine hydrochloride (HCl) 1% on corneal endothelial cell function, ultrastructure, and viability using an in vitro perfusion specular microscope system. DESIGN: Paired rabbit and human corneas were isolated and mounted in an in vitro specular microscope for endothelial perfusion evaluation. Corneas were perfused with a control solution (BSS Plus for humans, glutathione bicarbonate Ringer's [GBR] for rabbits) for a 1-hour stabilization period. After the stabilization period, one cornea of each matched pair was perfused with preservative-free lidocaine HCl 1% for 15 minutes followed by control solution for an additional 2 to 3 hours. The control cornea continued to receive either GBR or BSS Plus. Corneal thickness measurements were taken every 15 minutes throughout the perfusion period. Corneal swelling and deswelling rates were calculated by linear regression analysis. At the end of the experiment, corneas were fixed for scanning and transmission electron microscopy. In another group of corneas, the endothelial viability was assayed after direct perfusion with lidocaine HCl 1%. RESULTS: Lidocaine HCl 1% caused endothelial cell edema, which reversed on removal of lidocaine from perfusion media. Corneal swelling and deswelling rates did not differ significantly between the lidocaine and control groups. Electron microscopy showed the effects of transient endothelial cell edema with an otherwise normal mosaic pattern and ultrastructure for both treatment groups. Endothelial cell viability was maintained after the direct lidocaine exposure and a 2-hour washout. CONCLUSIONS: Lidocaine HCl 1% causes a transient endothelial cell edema to the in vitro perfused endothelium of human and rabbit corneas. Proper attention should be given to the type of lidocaine injected intraocularly (i.e., concentration, vehicle, preservatives, pH, osmolarity). Although lidocaine HCl 1% appears to be safe to both human and rabbit endothelium during short-term in vitro exposure, further in vivo and in vitro studies are needed to determine long-term effects of intraocular lidocaine on the corneal endothelium.

Aged↗
PubMed1998

Post-transplant diabetes with anti-glutamic acid decarboxylase antibody during tacrolimus therapy.

A 54-year-old man undergoing hemodialysis because of end-stage renal failure was transplanted with a cadaver kidney in November 1997. He had no history of diabetes. Tacrolimus was used as the primary immunosuppressant. Three weeks after transplantation, he developed insulin-requiring diabetes mellitus. Anti-glutamic acid decarboxylase antibody was not detected on the third post-operative day, but appeared 4 weeks after transplantation. The recipient had DNA haplotypes that indicated susceptibility to Type 1 diabetes in Japanese subjects. Immunosuppressive therapy was changed from tacrolimus to cyclosporin. Thereafter, titer of anti-glutamic acid decarboxylase antibody disappeared and the patient's insulin requirement was notably reduced. The mechanism underlying the development of diabetes in this case appears to be, in part, direct beta-cell toxicity due to tacrolimus therapy, resulting in secondary beta-cell autoimmunity. This case suggests that tacrolimus therapy after transplantation should be used with caution in patients with genetic susceptibility to Type 1 diabetes.

Antibodies↗
PubMed1998

Sensitivity in detection of hypervascular hepatocellular carcinoma by helical CT with intra-arterial injection of contrast medium, and by helical CT and MR imaging with intravenous injection of contrast medium.

PURPOSE: To determine the effectiveness of i.a. contrast-enhanced helical CT and of i.v. contrast-enhanced helical CT and MR imaging, in detecting hypervascular hepatocellular carcinoma (HCC). MATERIAL AND METHODS: Fifty patients with 125 hypervascular HCC nodules underwent helical CT both during arterial portography (CTAP) and during hepatic arteriography (CTHA). Helical CT and MR imaging of the entire liver with i.v. administration of contrast medium were also performed. Helical CT images were obtained at 30-33 s (arterial-phase CT) and at 5 min (equilibrium-phase CT) after the initiation of an i.v. bolus injection of contrast medium. After T1- and T2-weighted spin-echo MR imaging, gradient-echo images during breath-holding were obtained prior to and 20 s, 1 min, and 2 min after the bolus administration of 0.1 mmol/kg of gadopentetate dimeglumine (dynamic MR). The sensitivity and positive predictive value of the various techniques were evaluated and compared. RESULTS: In terms of sensitivity for hypervascular HCC nodules of less than 1 cm in diameter, CTAP (90%) and CTHA (88%) were significantly superior to dynamic MR imaging (44%), arterial-phase CT (39%), spin-echo MR imaging (20%), and equilibrium-phase CT (7%) (p < 0.001). However, there was no significant difference in the techniques with regard to the detection of lesions equal to or more than 2 cm in diameter. CONCLUSION: For detecting small hypervascular HCCs, helical CT with i.a. contrast enhancement is superior to helical CT and MR imaging with i.v. enhancement.

Adult↗
PubMed1998

Ultrasound biomicroscopy and histopathology of sclerocornea.

PURPOSE: We present a clinicopathologic case report of sclerocornea with the intent of showing the usefulness of ultrasound biomicroscopy (UBM) and the correlation of histopathologic findings. METHODS: An infant with congenital bilateral sclerocornea was seen for an evaluation under anesthesia. Dense opacification of both corneas prevented adequate examination of both anterior and posterior segments of the eye. UBM was performed preoperatively with subsequent corneal transplantation of the left eye. The corneal button was submitted for histopathologic examination. RESULTS: Preoperative UBM proved helpful in assessing the status of the cornea as well as the anterior chamber and its structures. Findings on histopathologic examination correlated well with the results on UBM and confirmed the diagnosis of sclerocornea. CONCLUSION: We recommend the use of UBM in assessing opacified corneas to assist in obtaining a diagnosis, to highlight potential associated structural anomalies, and to help guide decisions regarding surgical management.

Cornea↗
PubMed1998

Effects of endoscopic variceal ligation on oxygen transport and the arterial lactate levels in patients with cirrhosis.

OBJECTIVE: Despite the increased cardiac output and oxygen delivery, an impaired oxygen uptake has been noted in patients with cirrhosis. We recently observed that endoscopic variceal ligation decreased the cardiac output due to a reduction in the cardiac preload. It is thus possible that a variceal ligation decreases the oxygen delivery and thereby negatively influences tissue oxygenation in patients receiving such treatment. We thus investigated the effects of variceal ligation on oxygen delivery, oxygen uptake, and the arterial lactate levels. METHODS: There were 22 patients with compensated cirrhosis and risky esophageal varices (Child's class A:B=13:9). Twelve patients underwent an endoscopic variceal ligation and 10 patients received gastroscopy as a control. The cardiac function, blood gas status, oxygen delivery, and arterial lactate concentration were also assessed before and after variceal ligation. The oxygen uptake was calculated by the Fick equation. RESULTS: Following variceal ligation, there was an immediate decrease in the cardiac output and oxygen delivery. The reduction in oxygen delivery was associated with a slight but significant increase in the arterial lactate concentration. The decreased oxygen delivery was also associated with a concomitant decrease in the oxygen uptake. In the control subjects, gastroscopy did not alter the systemic hemodynamics, arterial oxygen status, or arterial lactate levels. CONCLUSION: We found a significant decrease in the oxygen delivery in patients undergoing an endoscopic variceal ligation. Such deteriorated tissue oxygenation may be serious especially in patients with a low oxygen transport ability such as in patients with variceal hemorrhage with anemia. However, the clinical significance of these changes remains unclear and further studies are therefore warranted.

Aged↗
PubMed1998

Preoperative staging of endometrial carcinoma: diagnostic effect of T2-weighted fast spin-echo MR imaging.

PURPOSE: To evaluate the usefulness of T2-weighted fast spin-echo magnetic resonance (MR) imaging with a 512 x 256 matrix for assessment of the preoperative stage of endometrial carcinoma. MATERIALS AND METHODS: Twenty-eight women with histopathologically proved endometrial carcinoma underwent preoperative T2-weighted fast spin-echo, dynamic T1-weighted fast spin-echo, and postcontrast T1-weighted spin-echo MR imaging with a phased-array surface coil. The uterine long-axis planes in each sequence were reviewed at separate sessions by three radiologists blinded to the histopathologic data. RESULTS: For the diagnosis of myometrial invasion, no statistically significant differences were found among T2-weighted imaging, dynamic imaging, and postcontrast T1-weighted imaging. For the diagnosis of deep myometrial invasion, T2-weighted and dynamic images showed higher specificity than postcontrast T1-weighted images (T2-weighted, 89%; dynamic, 88%; and postcontrast T1-weighted, 80%). For cervical invasion, T2-weighted and dynamic images showed larger areas under receiver operating characteristic curves than did postcontrast T1-weighted images (T2-weighted, 0.78; dynamic, 0.71; and postcontrast T1-weighted, 0.67). CONCLUSION: T2-weighted imaging is useful for identifying the stage of endometrial carcinoma.

Carcinoma↗
PubMed1998

FEESST: a new bedside endoscopic test of the motor and sensory components of swallowing.

We here introduce an office or bedside method of evaluating both the motor and sensory components of swallowing, called fiberoptic endoscopic evaluation of swallowing with sensory testing (FEESST). FEESST combines the established endoscopic evaluation of swallowing with a technique that determines laryngopharyngeal (LP) sensory discrimination thresholds by endoscopically delivering air pulse stimuli to the mucosa innervated by the superior laryngeal nerve. Endoscopic assessment of LP sensory capacity followed by endoscopic visualization of deglutition was prospectively performed 148 times on 133 patients with dysphagia over an 8-month period. The patients had a variety of underlying diagnoses, with stroke and chronic neurologic disease predominating (n = 94). Subsequent to LP sensory testing, a complete dysphagia evaluation was conducted. Various food and liquid consistencies were dyed green, and attention was paid to their management throughout the pharyngeal stage of swallowing. Evidence of latent swallow initiation, pharyngeal pooling and/or residue, laryngeal penetration, laryngeal aspiration, and/or reflux was noted. Recommendations for therapeutic intervention were based on information obtained during the FEESST and often involved the employment of compensatory swallowing strategies, modification of the diet or its presentation, placement on non-oral feeding status, and/or referral to other related specialists. All patients successfully completed the examination. In 111 of the evaluations (75%), severe (>6.0 mm Hg air pulse pressure [APP]) unilateral or bilateral LP sensory deficits were found. With puree consistencies, 31% of evaluations with severe deficits, compared to 5% of evaluations with either normal sensitivity or moderate (4.0 to 6.0 mm Hg APP) LP sensory deficits, displayed aspiration (p < .001, chi2 test). With puree consistencies, 69% of evaluations with severe deficits, compared to 24% with normal or moderate deficits, displayed laryngeal penetration (p < .001, chi2 test). FEESST allows the clinician to obtain a comprehensive bedside assessment of swallowing that is performed as the initial swallowing evaluation for the patient with dysphagia.

Adult↗