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Biomedical subjects

H C Kim

Publications and source records attributed to H C Kim.

At least 181 records · Page 10Linked to original sources
PubMed1997

The presurgical management with erythrocytapheresis of a patient with a high-oxygen-affinity, unstable Hb variant (Hb Bryn Mawr).

BACKGROUND: Hemoglobin (Hb) Bryn Mawr is an unstable Hb variant resulting in congenital hemolytic anemia. This variant Hb also has an increased affinity for oxygen. The perioperative transfusion management of this disorder is described, and the first genomic analysis of this Hb variant is given. CASE REPORT: An 11-year-old boy, heterozygous for Hb Bryn Mawr, was referred for cholecystectomy. Sequence analysis of genomic DNA confirmed that the patients was heterozygous for a T-->C transition in the codon for amino acid 85, causing a substitution of serine for phenylalanine in the beta-globin chain. On the basis of whole-blood O2 dissociation studies, projected tissue O2 delivery would have been suboptimal during general anesthesia; therefore, a partial red cell exchange transfusion was performed to lower variant Hb and prevent tissue hypoxia during surgery. The red cell mass to be exchanged (50%) was determined from the calculated increase in O2 delivery capacity required to maintain an O2 extraction of 4 to 5 mL of O2 per dL of whole blood. The p50 of whole blood from the patients immediately after the exchange transfusion was 16.0 torr. At the time of surgery, the p50 was normal (25.9 torr). The patient's whole blood 2,3 DPG levels were 4.70 mmol per mL of red cells (before transfusion) (normal range = 4.8 +/- 0.3 mmol/mL red cells), 4.07 mmol per mL of red cells (immediately after transfusion), and 4.55 mmol per mL of red cells (48 hours after transfusion). CONCLUSION: This patient with Hb Bryn Mawr was prepared for surgery with a partial exchange transfusion to prevent tissue hypoxia during anesthesia. Decreased 2,3 DPG levels immediately after transfusion resulted in increased O2 affinity of whole blood; however, 48 hours after exchange transfusion, a normal p50 (due to both removal of variant Hb and regeneration of 2,3, DPG) was observed. Partial exchange transfusion is useful in the preoperative management of patients with Hb variants characterized by increased O2 affinity.

2,3-Diphosphoglycerate↗
PubMed1997

A case of fatal hemolytic disease of the newborn associated with-D-/-D-phenotype.

-D- is a rare haplotype that determines D without C, c, E or e, and exalted D activity. The extremely rare homozygote propositi (-D-/-D-) are usually ascertained through their immune antibodies, anti-Rh17 (Hro), which react with red cells of all common Rh phenotypes. The authors experienced the first case in Korea of a woman with -D- phenotype. She had a history of spontaneous abortion, therapeutic termination and red cell transfusion, and at her third pregnancy she delivered a baby with severe hemolytic disease of the newborn. In spite of intensive medical intervention, the baby died of hydrops fetalis. An immune antibody to high incidence Rh antigen, namely anti-Rh17(Hro), was demonstrated in the woman's serum. A family study revealed that the -D- gene complex was present in all its members and one of the woman's sisters was also -D- homozygote. In the serum of this sister, anti-Rh17(Hro) was also present.

Erythroblastosis, Fetal↗
PubMed1997

Hepatic uptake of Tc-99m MDP on bone scintigraphy from intravenous iron therapy (Blutal).

Two patients with hypochromic microcystic anemia received intravenous iron therapy (Blutal, Yuham Co., An Yang, Korea). These patients demonstrated diffuse hepatic uptake of Tc-99m MDP on bone scintigraphy, which was performed for evaluation of lower back pain in one patient and to rule out skeletal metastases from gastric cancer in the other patient. Blutal is an iron colloid chondroitin sulfate complex and is used to treat iron deficiency anemia in Korea. Phagocytized iron colloid within the hepatic reticuloendothelial system is responsible for the hepatic uptake of Tc-99m phosphate in the two presented cases.

Adult↗
PubMed1997

Development of a microcontroller-based automatic control system for the electrohydraulic total artificial heart.

An automatic physiological control system for the actively filled, alternately pumped ventricles of the volumetrically coupled, electrohydraulic total artificial heart (EHTAH) was developed for long-term use. The automatic control system must ensure that the device: 1) maintains a physiological response of cardiac output, 2) compensates for an nonphysiological condition, and 3) is stable, reliable, and operates at a high power efficiency. The developed automatic control system met these requirements both in vitro, in week-long continuous mock circulation tests, and in vivo, in acute open-chested animals (calves). Satisfactory results were also obtained in a series of chronic animal experiments, including 21 days of continuous operation of the fully automatic control mode, and 138 days of operation in a manual mode, in a 159-day calf implant.

Algorithms↗
PubMed1997

Mechanistic insights into chemopreventive effects of phenethyl isothiocyanate in N-nitrosobis(2-oxopropyl)amine-treated hamsters.

The influence of phenethyl isothiocyanate (PEITC) on cell kinetics in the target organs of N-nitrosobis(2-oxopropyl)amine (BOP) tumorigenicity and on xenobiotic-metabolizing enzymes was investigated in hamsters. Female 5-week-old Syrian hamsters were given a single s.c. dose of 0, 20 or 50 mg/kg of BOP 2 h after receiving PEITC by gavage at a dose of 0, 100 or 250 mumol/animal (0, 16.3 or 40.8 mg/animal). Six and 22 h after the BOP administration, hamsters were killed and tissues were sampled. Proliferating cell nuclear antigen immunohistochemistry demonstrated significant reduction (P < 0.05-0.001) by PEITC of the labeling indices in the pancreatic acini and ducts, bronchioles, and renal tubules of the BOP-treated animals in a dose-dependent manner. In the lungs, the PEITC pretreatment significantly (P < 0.001) reduced the O6-methyldeoxyguanosine levels as compared to the BOP-alone value. Immunoblot analysis of liver cytochrome P450 isoenzymes showed CYP 2B1 to be mainly involved in the metabolic activation of BOP. PEITC significantly (P < 0.05) inhibited the induction of several isoenzymes, including CYP 2B1, while lowering the hepatic glutathione S-transferase activity as well as glutathione levels, regardless of BOP administration. Our results thus suggest that PEITC exerts its chemopreventive activity against BOP initiation of carcinogenesis in hamsters by decreasing cell turnover and DNA methylation in the target organs, and by influencing hepatic xenobiotic-metabolizing phase I enzymes, although the relationship, if any, of the latter with the former events remains to be investigated.

Animals↗
PubMed1997

A low dose of streptozotocin prevents kainic acid-induced seizures and lethal effects in the rat.

1. The effect of streptozotocin (STZ), a nitric oxide (NO) donor, on kainic acid (KA)-induced neurotoxicity was examined in Sprague-Dawley rats. 2. The administration of KA (8 mg/kg, i.p.) produced significant neurotoxicity accompanied with increased immunoreactivity for Fos-related antigen in the rat hippocampus. 3. Pretreatment with STZ (15 mg/kg, i.m.) significantly blocked the neurotoxicity induced by KA. 4. Thus, the neuroprotective effect of STZ may, at least in part, reflect the role of NO in inhibiting seizures.

Animals↗
PubMed1997

Moving actuator type total artificial heart with reverse position of the aortic and pulmonary conduits.

Adequate intrathoracic anatomical compatibility is one of the most important considerations in designing a fully implantable total artificial heart (TAH). We have recently developed an innovative concept of reverse positioning of the aortic and pulmonary conduits to facilitate anatomical compatibility of the moving actuator type TAH. The pulmonary conduit of this TAH is designed to be located posterior to the aortic conduit, which results in a substantial reduction in the anteroposterior diameter of this heart, as well as the virtual elimination of the compression of the low pressure pulmonary conduit. In ovine orthotopic implantation experiments with this model of the TAH, we consecutively achieved 3 day survival in 1 sheep and 2 day survival in another. To the best of our knowledge, these were the first significant short-term survival cases in the orthotopic implantation of electric TAHs in sheep.

Animals↗
PubMed1997

Do sheep really have problems with cardiopulmonary bypass for total artificial heart implantation?

Although the use of sheep in total artificial heart (TAH) implantation has many advantages, they are known to show a significant morbidity rate on cardiopulmonary bypass (CPB); this has been considered to be a major limiting factor in using them for TAH experiments. We conducted a series of ovine CPB experiments to evaluate the sheep's pathophysiological response to CPB. CPB-related hemolysis, bleeding, and lung dysfunction were analyzed in 5 sheep, which had undergone CPB, used at our hospital for TAH implantation. Four of the 5 sheep survived the experimental procedures, and 3 of them survived on a long-term basis. Unacceptable degrees of hemolysis related to CPB were not observed. Postoperative bleeding was not remarkable, and coagulation test results did not show significant abnormal findings. Acute lung injuries of a mild to moderate degree were found mainly at the microscopic level, but rarely had clinical significance. In conclusion, this experiment suggests that sheep can be used for the animal model for TAH implantation with acceptable risk on CPB circuits and techniques are used.

3,4-Methylenedioxyamphetamine↗
PubMed1997

Brain abscess and brain tumor: discrimination with in vivo H-1 MR spectroscopy.

PURPOSE: To determine the ability to differentiate brain abscess from cystic or necrotic brain tumor with hydrogen-1 magnetic resonance (MR) spectroscopy. MATERIALS AND METHODS: H-1 MR spectroscopy was prospectively performed in seven consecutive patients with pyogenic brain abscess and in seven consecutive patients with necrotic or cystic brain tumor (five patients with glioblastoma and one each with pilocytic astrocytoma and metastasis from lung cancer) in whom radiologic images depicted ring-shaped areas of contrast material enhancement (indicative of a cystic or necrotic mass). Assignment of resonance peaks to metabolites was based on reports in the literature. RESULTS: In six of seven patients with abscess, there were various resonances attributed to lactate, valine, alanine, leucine, acetate, succinate, and unidentified metabolites (2.2, 2.9, 3.2, 3.4, and 3.8 ppm). In six of seven patients with tumor, there was only a resonance attributed to lactate. One patient with a tumor had an unidentified peak at 0.9 ppm (presumably attributed to lipid) in addition to the peak attributed to lactate. CONCLUSION: Spectral patterns from in vivo H-1 MR spectroscopy may permit differentiation of brain abscess from necrotic or cystic tumor.

Adult↗
PubMed1997

Sleep-disordered breathing and neuropsychological deficits. A population-based study.

The relationship of sleep-disordered breathing (SOB) to neuropsychological deficits was investigated with cross-sectional data from the Wisconsin Sleep Cohort Study, a population-based study of the natural history of SDB. A sample of 841 employed men and women ages 30 to 60 yr was studied by overnight polysomnography to assess the frequency of apneas and hypopneas per hour of sleep (apnea-hypopnea index, AHI). Prior to overnight polysomnography, the participants were given a battery of neuropsychological tests for functionally important capacities including motor skills, attention, concentration, information processing, and memory. Principal factor analysis of all the neuro-psychological test data revealed a psychomotor efficiency and a memory factor. Multiple regression analysis showed a significant negative association between logarithmically transformed AHI (LogAHI) and psychomotor efficiency score independent of age, gender, and educational status (p = 0.017). The relationship was not explained by self-reported sleepiness. No significant relationship was seen between LogAHI and memory score. In assessing the clinical significance of mild SDB, we estimate that an AHI of 15 is equivalent to the decrement in psychomotor efficiency associated with 5 additional yr of age, or to 50% of the decrement associated with hypnosedative use.

Adult↗
PubMed1997

Acute Myelitis after hepatitis B vaccination.

We report a case of myelitis after plasma-derived hepatitis B vaccination. The patient was a 31-year-old man who presented with progressive sensory symptoms in extremities that developed 2 weeks after a third vaccination. MRI of the cervicothoracic region revealed swelling and T2 high signal at the level of C4 to C5 cord, and isolated enhancement in the posterior columns between C4 and C5 cord. The significance of MRI findings and HLA haplotype of the patient will be briefly discussed.

Acute Disease↗
PubMed1997

Effects of Cryptosporidium baileyi infection on the bursa of Fabricius in chickens.

In order to clarify the effect of cryptosporidiosis on immune response, histopathological changes associated with experimentally occurring bursal cryptosporidiosis in chickens were chronologically observed as the first step. A total of 150 2-day-old chickens was each inoculated orally with a single dose of 5 x 10(5) Cryptosporidium baileyi oocysts. The chickens showed a normal profile of oocyst shedding in droppings. The bursa indices throughout the experimental period indicated negligible reactions. Numerous cryptosporidia occurred in the microvillous border of bursal epithelium between days 4 and 16 postinoculation (PI). Appearance of the most mast cells was followed by a dramatic loss of the protozoa in the bursa of Fabricius (BF). The distribution of the coccidium coincided with heterophil infiltration in the epithelium and adjacent lamina propria. The histopathological lesion was marked diffuse chronic superficial purulent bursitis with heterophil infiltration in the epithelium and adjacent lamina propria and mucosal epithelial hyperplasia. These results suggest that the bursitis may induce immunosuppressive effect.

Animals↗
PubMed1997

Effects of Cryptosporidium muris (strain MCR) infection on gastric mucosal mast cells in mice.

The responses of gastric mucosal mast cells (GMMCs) to infection with coccidian protozoa, Cryptosporidium muris, in mice were examined during primary and challenge infections. Each of three-week old ICR SPF mice was orally inoculated with a single dose of 2 x 10(6) oocysts of C. muris (strain MCR). After oocyst shedding ceased, the mice were orally challenged with a single dose of 2 x 10(6) oocysts of the same species. GMMCs reached a peak on days 20-30 postinoculation (PI) in number, and decreased thereafter. An increase on days 20-30 post-challenge-infection (PCI) was also observed. The mice showed, on the whole, normal profiles of oocyst shedding in droppings. The number of the cells of uninfected control mice remained constant. Judging from the above results, it is suggested that mastocytosis correlate with expulsion of C. muris in primary infection and the defense mechanism of challenge infection.

Animals↗
PubMed1997

Macroaspartasemia as a cause of isolated elevation of aspartate aminotransferase--its biochemical and physiological characteristics.

OBJECTIVES: The increase of serum aspartate aminotransferase (AST) is generally found in hepatic, cardiac, muscular disease and hemolytic disorders of the red blood cell (RBC). The elevation of its activity is suspected in pathological conditions of these organs. However, instances without any of those conditions rarely exist. METHODS: The experimental samples were obtained from a normal person's hemolysed RBC, a hepatitis patient and a macroaspartatemic female's serum. They were studied with exclusion chromatography, electrophoresis of AST and changes of AST activity due to Polyethylene Glycol (PEG) and various conditions on storage. RESULTS: 1) The patterns of AST activity by exclusion chromatography are similar to the hemolysed RBC and the hepatitis's serum but differs by the isolated AST elevation. 2) The AST activity with addition of PEG and different anti-immunoglobulin subtypes to different serums are slightly decreased in hepatitis but markedly decreased with PEG and anti-IgG in macroaspartatemia. 3) The patterns of AST activity in electrophoresis are single band-cytosomal AST (cAST)-from hemolysed RBC and two bands-mitochondrial AST (mAST) and cAST-from hepatitis, the major being cAST and the minor mAST. Even though there are two bands, the major one is atypical and the minor corresponds to mAST in macroaspartatemia. 4) The changes of AST activity on storage according to time and temperature show to be stable over 4 weeks at room temperature and cooled condition, and 9 weeks under frozen state in macroaspartatase. CONCLUSION: Concluding from the above findings, macroaspartatemia is an enzyme-immunoglobulin complex composed of cAST with IgG. MacroAST might be stabler than usual AST at physical conditions.

Adult↗
PubMed1997

Activation of protein tyrosine phosphorylation after retinal branch vein occlusion in cats.

PURPOSE: The authors examine the effect of retinal branch vein occlusion (BVO), a common retinal vascular disorder, on protein tyrosine phosphorylation, production of angiogenic growth factors, and activation of signal proteins in the tyrosine kinase pathways in the retina. METHODS: Retinal branch vein occlusion was induced in cat retina by coagulation of retinal veins with diathermy. At 2 days, 1, 3, and 6 weeks after induction of BVO, the retina was divided into three parts: a part within the distribution of the occluded vein (BVO[IN]) or a part outside the distribution of the occluded vein (BVO[OUT]). Each part of the retina was prepared for Western blot analysis of tyrosine-phosphorylated proteins, vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and four signal proteins in the tyrosine kinase pathways, which were phospholipase C gamma (PLC gamma), C-Src, SH2-containing protein (SHC), and mitogen-activated protein kinase (MAPK). RESULTS: Overall, tyrosine-phosphorylated proteins were increased after BVO, especially in BVO(IN) at 2 days and 1 week. The VEGF and bFGF also were increased in BVO(IN) at 1 week and 2 days, respectively. The PLC gamma and MAPK were activated at these time points. The C-Src and SHC were not activated in the retina after BVO. CONCLUSIONS: The BVO increased overall protein tyrosine phosphorylation in the cat retina in association with increase of angiogenic growth factors (VEGF and bFGF) and activation of two signal proteins (PLC gamma and MAPK) in the tyrosine kinase pathways. These results suggest that the protein tyrosine phosphorylation may in part play an important role in mitogenesis of vascular endothelial cells and other retinal responses after BVO.

Animals↗
PubMed1997

Genistein, a protein tyrosine kinase inhibitor, ameliorates retinal degeneration after ischemia-reperfusion injury in rat.

PURPOSE: The authors sought to determine the effect of genistein, a naturally occurring protein tyrosine kinase inhibitor, in a model of ischemia-reperfusion injury in the rat retina. METHODS: Ischemia-reperfusion injury was induced by temporary optic nerve ligation. A dose of 0.034 mg, 0.34 mg, and 3.4 mg of genistein or dimethyl sulfoxide (DMSO) alone was injected intraperitoneally 1 hour before the ligation of the optic nerve and just after the start of reperfusion. After 48 hours of reperfusion, the effect of genistein on overall protein tyrosine phosphorylation in the retina was studied using Western blot analysis. After 168 hours, the effect of increasing doses of genistein on retinal degeneration was examined by quantitative morphometric analysis of histologic sections of the retina. RESULTS: The authors found that tyrosine phosphorylation was increased after 48 hours of reperfusion in the ischemia-reperfusion-injured eyes treated with DMSO alone. A severe inner retinal degeneration was observed in the animals treated with DMSO alone after 168 hours of reperfusion. The treatment with 3.4 mg genistein inhibited the increase in tyrosine phosphorylation and protected the eyes significantly from the induced ischemic retinal degeneration by morphometric analysis of the mean thickness of the inner limiting membrane to the outer limiting membrane, the inner plexiform layer, and the inner nuclear layer (P < 0.02). Treatments with lower amounts of genistein (0.034 mg and 0.34 mg) did not show a significant protection of retinal degeneration after the injury. CONCLUSIONS: Systemic administration of high dose of genistein, a dietary-derived isoflavone, can ameliorate an ischemia-reperfusion-induced retinal degeneration. Genistein may be useful to prevent neuronal degeneration in the inner retina as a result of ischemic injury.

Animals↗
PubMed1997

Dextromethorphan alters the reinforcing effect of cocaine in the rat.

Dextromethorphan (DM) at supra-antitussive doses produces psychotomimetic effects in humans. In order to achieve a better understanding of the pharmacological mechanisms responsible for the behaviors induced by DM, we examined the effects of DM on the intravenous self-administration of cocaine in the rat. The effects of DM (40 mg/kg, p.o.) on responding for 0.5, 0.25, 0.125, 0.06 and 0.03 mg/kg/infusion of cocaine was assessed. DM decreased the rate of responding for higher doses of cocaine (0.5, 0.25 and 0.125 mg/kg/infusion), and increased the rate of responding for lower doses of cocaine (0.06 and 0.03 mg/kg/infusion), suggesting that DM shifted the dose-response curve for cocaine self-administration to the left. Therefore, our results indicate that the sensitivity to cocaine's behavioral effects appears to be enhanced by DM.

Animals↗