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Publications and source records attributed to Y M Kim.
A stable sulfone derivative of 2,4,6-trimethylcyclohexa-2,4-diene-1-one (7) undergoes facile ring cleavage under visible light to produce a ketene intermediate, which could be efficiently captured by amines to give amides even in the presence of competing nucleophiles such as water and ethanol.
We describe a rapid and efficient diagnostic method for sex determination and the dystrophin gene by the polymerase chain reaction (PCR) using archived cytogenetic slides. Archived cytogenetic slides stored for about 4 years at room temperature were used. To confirm whether DNA analysis is possible using the archived cytogenetic slides, we extracted the DNA from the slides and amplified the Y centromeric region (DYZ3), the X centromeric region (DXZ1) and the exon 46 of the dystrophin gene. Of the 50 cases, 24 were peripheral bloods, 13 were amniotic fluid cells, 5 were chorionic villus samplings and 8 were cord bloods. The PCR related sex determination in 22 females and 28 males, showed 100% concordance with the results of chromosome analysis, and all cases showed positive band for the exon 46 of the dystrophin gene. Of the 50 cases of the archived cytogenetic slides, we were fortunate enough to obtain the fresh blood sample from one fetus whose karyotype showed 45,X[34]/46,X,+mar[145] to compare the results of the gDNA with that from archived cytogenetic slide. To confirm whether the marker chromosome was derived from Y chromosome, we studied the six loci (PABY, SRY, RPS4Y (SY16, 17), ZFY, DYS14) on the short arm, one locus (DYZ3) on the centromere and one locus (DYZ1) on the long arm. Of the 8 loci studies, all PCR related Y chromosome showed positive band from both gDNA obtained from cord blood and archived cytogenetic slides. We could conclude from the above results that the marker chromosome was derived from the Y chromosome. We believe our experiment is rapid and efficient for studies of over 10 independent loci from a single slide which has been kept in storage for up to 4 years and that archival Giemsa-stained cytogenetic slide repositories represent valuable DNA resources for clinical and forensic studies.
The promoter of the mouse inducible nitric oxide synthase (iNOS) has a putative octamer motif (ATGCAAAA) which exists 24 bp upstream from the TATA box and is mismatched at a single residue from the consensus octamer motif. To examine whether this site is involved in iNOS expression, we constructed various deletions and site-directed mutants of the iNOS promoter linked to the chloramphenicol acetyltransferase (CAT) reporter gene, transfected the constructs into RAW 264.7 macrophages, and stimulated the cells with interferon-gamma (IFN-gamma) and/or lipopolysaccharide (LPS). CAT activity was not induced by LPS in constructs containing only the octamer motif (-71 to +82), but was induced with constructs containing the octamer motif and the upstream sequences of the NF-kappaB site (-91 to +82). However, a site-directed mutation of the octamer motif in the context of the -91 to +82 promoter construct or an extended promoter construct (-1542 to +82) abolished IFN-gamma and/or LPS-induced CAT activity. Similar results were obtained from site-directed mutants at either the NF-kappaB site or both the NF-kappaB site and octamer motif in these two constructs. In addition, we demonstrated that the conversion of the iNOS octamer motif into a consensus sequence increased CAT activity. Electrophoretic mobility shift assay (EMSA) performed with the NF-kappaB site or the octamer motif-containing oligonucleotide probe revealed that NF-kappaB binding was induced by LPS treatment, while the Oct-1 binding was constitutive. Competition assays performed with octamer-related oligonucleotide competitors derived from the immunoglobulin-kappaB or SV40 promoter confirmed the identity of the iNOS promoter sequence as being a Oct-1 binding site. EMSA carried out using a probe containing both the NF-kappaB site and the octamer motif identified two LPS-induced complexes. Competition assays with each NF-kappaB site or octamer motif competitor revealed that NF-kappaB and Oct-1 were present in these two complexes. These data suggest that, besides the NF-kappaB site, the octamer motif is essential for the maximal expression of the iNOS gene in murine macrophages, and the direct interaction of Oct-1 and NF-kappaB is important for the regulation of this gene.
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Exposure to cadmium (Cd) impairs renal transport systems for glucose, amino acids, phosphate, and dicarboxylates. To investigate if these changes are directly related to a Cd binding to the renal brush-border membrane, Cd binding and the Na+-dependent uptakes of d-glucose, l-alanine, phosphate, and succinate were determined in rat renal brush-border membrane vesicles (BBMV) exposed to CdCl2. Cd uptake by BBMV showed time and concentration dependence. Changes in medium osmolality had no effect on Cd uptake, indicating that the process primarily involves binding of Cd to the membrane. Scatchard analysis indicated the presence of two types of Cd binding sites, differing in affinity and number. Increasing the medium Cd concentration from 50 to 200 microM resulted in a progressive increase in Cd binding to the membrane and decrease in Na+-dependent transport of d-glucose, l-alanine, inorganic phosphate, and succinate. In all cases, the inhibition of transport was directly proportional to the total amount of Cd binding to the membrane. These results suggest that, during chronic exposure to Cd, free Cd ions liberated in renal tubular cells may directly interact with brush-border membranes and impair Na+-dependent solute transports.
Congenital brain tumors are very rare, and 2-9% of them are accounted for by glioblastomas. We encountered a case of congenital glioblastoma detected at the 39th week of gestation by fetal sonography, which revealed a large echogenic mass in the left temporo-parietal area of the fetal brain with significant midline shift and dilatation of the contralateral lateral ventricle. A detailed sonogram obtained 7 h later showed that the mass had increased in size, and this suggested an expanding hematoma. An emergency cesarean section was performed. Postnatal MRI demonstrated an enhancing mass with a large hematoma. Biopsy revealed a malignant brain tumor. Further management was refused and the boy died 6 days after birth. The postmortem pathological diagnosis was glioblastoma. When fetal sonography demonstrates an echogenic mass, a congenital brain tumor should be considered. The mode of delivery should be determined by the nature of the mass and the condition of the fetus.
To investigate clinical features, treatment outcome and prognostic factors of pediatric supratentorial primitive neuroectodermal tumors(ST-PNETs), 28 ST-PNET cases were retrospectively analyzed. The prognostic importance of age, sex, size of tumor, M stage, extent of surgical resection, histological features, immunohistochemical labelling indices (Ki-67, p53), and apoptotic index were assessed. The mean age at diagnosis was 6.8 years, and the male-to-female ratio was 18:10. The presenting symptoms in 22 cases were increased intracranial pressure and focal neurological deficits. Gross total resection was achieved in 17 cases, near-total (>90%) resection in 3, and subtotal in 7; biopsy was performed in 1 case. The mean duration of follow-up was 37 months. For 25 patients who completed planned adjuvant therapy, the 3-year survival rate was 73%. Univariate analysis showed that the presence of tumor necrosis (P=0.002) and extent of resection (P=0.04) correlated with survival. Patients with a high Ki-67 labelling index (>10%) tended to have shorter survival (P=0.095). In multivariate analysis, tumor necrosis showed statistical significance(P=0.03).
The inflammatory response of the liver to hemorrhagic shock includes the production of acute phase proteins and a variety of mediators, such as the cytokine interleukin (IL)-6. The transcription of acute phase protein genes in hepatocytes has been shown to be activated by Stat3, one of six distinct signal transducers and activators of transcription (STAT) proteins. IL-6 signals through activation of Stat3. In this study, we examined whether or not Stat3 was activated and IL-6 mRNA produced in the liver of rats subjected to hemorrhagic shock and whether or not both phases of shock, the ischemic and the resuscitation phases, were required. We report here that Stat3 activation and increased IL-6 expression required resuscitation and displayed identical kinetics following resuscitation, suggesting that liver production of IL-6 was responsible for liver Stat3 activation in hemorrhagic shock.
BACKGROUND: Although several reports have claimed that the appendix can be involved as a skip lesion in ulcerative colitis, they do not exclude the possibility that this skip lesion occurs as a result of medical therapy. Also, little is known about the relation between the presence of appendiceal orifice inflammation and the extent of the disease. METHODS: The presence of appendiceal orifice inflammation was prospectively assessed both endoscopically and histologically in 94 patients with active ulcerative colitis, the extent of whose disease had not been beyond the hepatic flexure. To evaluate the effect of prior medical therapy on the prevalence of appendiceal orifice inflammation, all cases were divided into two groups. Group A consisted of 66 patients who had been treated before inclusion; group B was composed of 28 patients newly diagnosed at inclusion. RESULTS: Appendiceal orifice inflammation was diagnosed in 24 (26%) of 94 patients with active subtotal ulcerative colitis, with no statistical difference observed between group A (23%) and group B (32%). In all 94 patients, the frequency of appendiceal orifice inflammation decreased significantly as the extent of disease increased, i.e., 37% in proctitis (n = 49), 17% in left-sided colitis (n = 36), and 0% in extensive colitis (n = 9) (p < 0.05). CONCLUSIONS: Appendiceal orifice inflammation as a skip lesion of ulcerative colitis is not rare, is more frequently observed in patients with less extensive disease, and is not the result of patchy improvement due to medical therapy.
PURPOSE: To investigate the role of nitric oxide (NO) in early endotoxemia on the systemic and regional blood flow by measuring the plasma nitrite/nitrate (NOx) and blood nitrosyl-hemoglobin (NO-Hb) levels. MATERIALS AND METHODS: This was a prospective, controlled, experimental study conducted in an animal research laboratory on 15 male mongrel dogs. Escherichia coli endotoxin (1 mg/kg) was injected intravenously. RESULTS: Hepatic, renal, and iliac blood flow and cardiac output (CO) were measured before and 15, 30, 45, 90 and 180 minutes after injection of Escherichia coli endotoxin (1 mg/kg) (n = 6). NOx efflux from the organs was calculated by measuring plasma NOx levels. The arterial blood levels of NO-Hb were also measured (n = 4). As control studies, blood samples from dogs (n = 5) without exposure to endotoxin were assayed at 180 minutes for NOx and NO-Hb. Following endotoxin injection, mean arterial pressure decreased and reached its lowest value at 90 minutes (baseline vs. 90 minutes: 119.1+/-5.8 vs. 82.5+/-16.7 mm Hg, P<.0001). Hepatic artery blood flow increased significantly (baseline vs. 180 minutes: 23.6+/-12.0 vs. 170.0+/-68.4 mL/ min, P<.0001). There were no significant changes in plasma levels of NOx, uptake or release of NOx across the measured vascular beds, NO-Hb levels at any time point. In the portal system, the portal vein flow correlated with NOx release (R = 0.69, P<.0001). CONCLUSION: In the early phase of endotoxemia in the dog, the significant reduction in systemic vascular resistance and hepatic arterial resistance are not associated with any measurable NOx release in the systemic circulation or the liver.
We investigated the catheterization and angiographic findings of 26 patients with Williams' syndrome to evaluate the natural course of supravalvar aortic stenosis and peripheral pulmonary arterial stenosis. The severity of the stenosis was correlated with age and body surface area in terms of the pulmonary arterial index, right ventricular systolic pressure, sinutubular ratio (ratio of measured to mean normal diameter of sinutubular junction), and systolic pressure gradient across the sinutubular junction. In patients with pulmonary arterial stenosis (n=20), right ventricular systolic pressure tended to decrease, and pulmonary arterial index increased, with increase in age and body surface area. Between the groups with and without pulmonary arterial stenosis, there was significant difference in age (mean 4.70 vs. 9.87, p=0.019), body surface area (0.62 vs. 1.16, p=0.002), pulmonary arterial index (152 vs. 317, p=0.002) and right ventricular systolic pressure (73.9 vs. 33.0, p=0.006). As all patients showed similar diameters at the sinutubular junction regardless of age and body size, sinutubular ratio decreased with increases in age and body surface area. The group with abnormal coronary arteries (n=7) had smaller sinutubular ratio (0.46 vs. 0.61, p=0.021) and higher pressure gradients between the left ventricle and the aorta (67.6 vs. 42.2, p=0.023) than did the group with normal coronary arteries. Stenosis of a coronary artery, or a branch of the aortic arch, was observed only in three patients with diffuse aortic stenosis. Our results suggest that, with time, peripheral pulmonary arterial stenosis tends to improve, and supravalvar aortic stenosis to progress. Failure of growth of the sinutubular junction might be responsible for the progression of the aortic lesion. Progression of the aortic lesion may be associated with involvement of the coronary arteries.
Current MR techniques enable both anatomical and functional evaluations of the heart. Although it is rarely used as a primary diagnostic tool in pediatric cardiology, it can be used as a valuable adjunct to echocardiography and angiography. MRI is particularly useful in clarification of morphology of complex congenital heart diseases. It is the most accurate method of determination of visceral and atrial situs. It is easy to evaluate the systemic and pulmonary venous connections that are very important for the Fontan type of operation, especially in patients with visceral heterotaxy. It facilitates demonstration of diminutive pulmonary arteries in patients with pulmonary atresia. It clearly demonstrates juxtaposition of the atrial appendages that is often missed by echocardiography. The anatomy of the twisted atrioventricular connections is much more clear in MRI than in echocardiography. It enables en face imaging of ventricular septal defect that provides a surgical view. We find en face imaging particularly helpful in patients with double inlet left ventricle and transposition of the great arteries where the size of the ventricular septal defect governs the blood flow into the aorta. It is often advantageous to echocardiography in defining the type of univentricular atrioventricular connections by demonstrating the position and topology of the rudimentary chamber in difficult cases. In double outlet right ventricle, the spatial relationship of the ventricular septal defect to the great arterial valves can be clearly defined by visualizing the ventricular septal defect and the outlet septum in the same imaging plane.
Granulocyte colony-stimulating factor (G-CSF) is an important regulator of granulopoiesis and an inducer of T helper 2 (Th2)-related cytokines. In this study we investigated the mechanism of cytokine-modulated G-CSF production in lipopolysaccharide (LPS)-stimulated peripheral blood mononuclear cells (PBMC) and bone marrow stromal cells (BMSC). In PBMC, LPS significantly induced G-CSF and interleukin (IL)-1, an inducer of G-CSF. Both were partly inhibited by IL-4, IL-6 and IL-10. None of these effects were the result of altered monocyte activation or proliferation. The effects of IL-4 and IL-10 appeared to be independent of IL-1 suppression or IL-1 receptor antagonist (IL-1ra) induction, but rather seemed to involve a blockade of IL-1 function, in addition to a blockade of IL-1-independent stimulatory effects on G-CSF production. The effect of the IL-6-induced suppression of G-CSF production differed from that of IL-4 and IL-10 in that it was much less pronounced and could be partially overridden by addition of functional IL-1, yet it also appeared to involve the interference with IL-1 function and the suppression of IL-1-independent mechanisms. In BMSC, G-CSF synthesis was regulated differently. Here, IL-1 was the main stimulator of G-CSF release, and the effect of IL-1 was neither affected by IL-10 nor IL-6, while IL-4 had a stimulatory effect. Thus, G-CSF production was found to be differently regulated in distinct cellular compartments, and a cross-regulation between these might be facilitated by IL-4-, IL-6- and IL-10-induced inhibition of IL-1. These results could be important for the understanding of G-CSF production in neutropenic patients during severe infection.
One of the most remarkable means by which tumour cells manage to evade recognition and elimination by the immune system is the release of immunosuppressive mediators, such as interleukin (IL)-10 or transforming growth factor-beta (TGF-beta). For antitumour immunotherapies to reach their full potential, cytokine cocktails will have to be custom-tailored to the tumour's individual cytokine microenvironment. One of the components of such a cytokine cocktail may be interleukin (IL)-15, which has demonstrated an excellent stimulatory potential of antitumour immunity. In an in vitro model, we have previously been able to show that the negative effects of IL-10 on IL-15-mediated cytotoxic T-cell activation can be outweighed by the addition of interleukin (IL)-12. The mechanism by which TGF-beta may influence the effect of IL-15 remains poorly understood, however. We have therefore taken our T-cell model further and have studied the effect of TGF-beta on IL-15-mediated interferon-gamma (IFN-gamma) production. In activated, IL-15-stimulated peripheral blood T lymphocytes, TGF-beta suppressed IFN-gamma mRNA and protein levels by approximately 75%. This effect was likewise observed on both CD4+ and CD8+ T cells and, in contrast to the effect of IL-10 in this system, could not be neutralized by the addition of IL-12. Thus, immunotherapy for TGF-beta-producing tumours may benefit from the addition of TGF-neutralizing activity rather than IL-12.
Disodium tetraethyleneglycol-bis-(alpha-carboxybenzylpenicillin) (TEG-carbenicillin), a tetraethyleneglycol (TEG) diester of carbenicillin, was synthesized to develop a carbenicillin prodrug with enhanced acid stability for oral administration. Antimicrobial activities of TEG-carbenicillin tested against gram-negative Escherichia coli (TG-1) and gram-positive Staphylococcus aureus (ATCC-12228) and Bacillus subtilis (NA-1) were comparable to that of carbenicillin. Stability of the beta-lactam ring of TEG-carbenicillin was determined by iodometry at pH 6.8, pH 4.5, and pH 2.0 at varied time intervals and was compared to that of carbenicillin. In 26 hr, both of the compounds were stable at pH 6.8. At pH 4.5, about 41% of the carbenicillin was decomposed, while TEG-carbenicillin was not appreciably decomposed. At pH 2.0, carbenicillin was decomposed about 61% after 6 hr, while TEG-carbenicillin was decomposed about 21% during the same period.
BACKGROUND: Mild hypothermia, a promising therapy being evaluated for various clinical situations, may suppress the formation of reactive oxygen species during reperfusion and may ameliorate microcirculatory perfusion failure (the "no-reflow phenomenon"). METHODS: Isolated rat livers underwent 30 min of perfusion, 2.5 h of ischemia, and 3 h of reperfusion. The temperature was maintained at 34 degrees C (mild hypothermia, n = 5) or 38 degrees C (normothermia, n = 6) for all three periods by perfusion of a modified Krebs Henseleit solution, air surface cooling, or both. A third group of livers was normothermic before and during ischemia and mildly hypothermic during reperfusion (reperfusion hypothermia, n = 6). Control livers had 3 h of perfusion at normothermia. Chemiluminescence (a measure of the generation of reactive oxygen species) and hepatic vascular resistance were monitored simultaneously to evaluate the effect of temperature on the formation of reactive oxygen species and the development of no reflow. Also measured were thiobarbituric acid reactive species and lactate dehydrogenase, as indicators of oxidative stress and cell injury. RESULTS: Mild hypothermia decreased formation of reactive oxygen species and postischemic increases in vascular resistance. Reperfusion hypothermia also decreased postischemic increases in vascular resistance, but not as effectively as did mild hypothermia. Levels of thiobarbituric acid reactive species were lower for reperfusion hypothermia than for mild hypothermia at only 0 and 30 min of reperfusion. Lactate dehydrogenase was significant only at 0 min of reperfusion for the normothermic group. Oxygen consumption did not change. CONCLUSION: The prevention of hepatic vascular injury by suppression of oxidative stress may be an important protective mechanism of mild hypothermia.
OBJECTIVE: To test the hypothesis that fasting would aggravate postischemic lipid peroxidation in a perfused rat liver model. DESIGN: Prospective, randomized study in a rat perfused liver model. SUBJECTS: Male Sprague-Dawley rats. INTERVENTIONS: Livers isolated from fed and fasted male Sprague-Dawley rats (n = 16) were exposed to 2.5 hrs of normothermic (38 degrees C) ischemia followed by 2 hrs of reperfusion. MEASUREMENTS AND MAIN RESULTS: Lipid peroxidation was measured by chemiluminescence and thiobarbituric acid reactive substances (TBARS). Injury parameters, potassium, lactate dehydrogenase efflux, and oxygen extraction were measured every 30 mins. Chemiluminescence and TBARS were greater in the fasted ischemic group during reperfusion. (fasted vs. fed: chemiluminescence, 946.8+/-205.5 [SEM] vs. 98.1+/-8.2 counts per second, p = .0004; thiobarbituric acid reactive substances, 1.11+/-0.25 vs. 0.21+/-0.032 nM/g of liver wt/min, p = .0019). Potassium efflux in the fasted group was greater than in the fed group. (1.568+/-0.082 vs. 1.28+/-0.079 microEq/g liver weight/min, p = .0184). Fasted livers extracted less oxygen after ischemia (1.94+/-0.22 vs. 1.14+/-0.46 microM/g liver wt/min, p = .0048). Lactate dehydrogenase levels showed no significant differences. CONCLUSION: Fasting augmented lipid peroxidation markedly. Nutrition may be an important mechanism that protects organs from oxidative injury.
RATIONALE AND OBJECTIVES: High signal intensity in the basal ganglia on T1-weighted MR imaging has been reported in chronic manganese (Mn) poisoning. However, the exact meaning of the high signal intensity remains unclear: does it result from Mn itself, secondary pathologic changes of the brain tissue, or both? The goal of this study was to evaluate the sequential change of MR signal intensity and to correlate the MR intensity of the globus pallidus and the hypothalamus with the Mn concentration in the blood and the brain tissue, and with the histopathologic findings. METHODS: Ten milligrams per kilogram of Mn was administered once a week for 4 weeks to 14 rabbits. The rabbits in the control group (n = 2) were killed without Mn administration; those in group I (n = 4) were killed 1 day after the completion of Mn administration, those in group II (n = 4) were killed at 4 weeks, and those in group III (n = 6) were killed at 8 weeks. Sequential MR imaging, blood and tissue concentration measurement, and pathologic examination were performed. Sequential changes of the percent contrasts, contrast-to-noise ratios, and T1 relaxation times were analyzed with blood and tissue concentrations and histopathologic findings. RESULTS: The signal intensity of the basal ganglia on T1-weighted imaging was highest 1 day after cessation of Mn administration and sequentially washed out. The contrast, contrast-to-noise ratio, and T1 relaxation time showed significant correlations with blood concentration. Only the T1 relaxation time of the globus pallidus showed a significant correlation with tissue concentration. Histopathologic examination disclosed mild abnormalities in the globus pallidus, thalamus, and hypothalamus. CONCLUSIONS: The high signal intensity on T1-weighted MR imaging presumably indicates mainly the exposure marker of Mn, although mild pathologic findings were observed.