Biomedical subjects

H K Kim

Publications and source records attributed to H K Kim.

At least 19 recordsLinked to original sources

PubMed1992

Mechanism of free fatty acid transfer from rat heart fatty acid-binding protein to phospholipid membranes. Evidence for a collisional process.

Fatty acid binding proteins (FABP) are a family of low molecular weight proteins found in many tissues that actively utilize free fatty acids (ffa). FABP would be expected to have a particularly important role in the heart, where over 80% of energy requirements are derived from oxidation of long chain fatty acids. The precise physiological function of heart FABP (H-FABP) has not been definitively identified, although it is thought to play a role in intracellular ffa transport. To examine the possible role of H-FABP in cardiac myocyte transfer of ffa, we examined the transfer of fluorescent anthroyloxy ffa (AOffa) from H-FABP to model phospholipid membranes, using a resonance energy transfer assay. In contrast to previous observations of ffa transfer from liver FABP and from membranes, transfer from H-FABP to membranes appears to occur by a different mechanism. AO-palmitate (16:0) transfer was 1.5-fold slower than AO-stearate (18:0) transfer, and mono-unsaturation did not affect the transfer rate. The AOffa transfer rate from H-FABP increased with increasing ionic strength and decreased slightly between pH 7 and 9. These results suggest that the rate of ffa transfer from H-FABP to membranes is independent of the ffa aqueous solubility. Thermodynamic analysis showed that the free energy of activation for the ffa transfer process arises primarily from an enthalpic component, with only a small entropic contribution, again suggesting the lack of an aqueous phase route of ffa delivery. Finally, the ffa transfer rate was found to be directly dependent on the concentration of acceptor membranes. These data therefore suggest that transfer of AOffa from H-FABP to membranes may occur via collisional interactions between the protein and membranes.

Animals↗

PubMed1992

Free fatty acid transfer from rat liver fatty acid-binding protein to phospholipid vesicles. Effect of ligand and solution properties.

Fatty acid binding proteins (FABP) are a family of 14-15-kDa proteins found in many mammalian cell types in high abundance. Although their precise physiological role remains hypothetical, the transfer of free fatty acids (ffa) to intracellular membrane sites is believed to be an important function of FABP. To better understand the role of FABP in this process, we have examined how the rate of ffa transfer from liver FABP (L-FABP) to model membranes is influenced by variations in ffa structure and properties of the aqueous phase. The rate of transfer of fluorescent anthroyloxy ffa to model acceptor membranes was monitored using a resonance energy transfer assay. The results show that a monounsaturated ffa transfers 2-fold more rapidly than a saturated ffa of equivalent chain length, and a two-carbon increase in acyl chain length results in a 3-fold decrease in transfer rate. The transfer rate decreases logarithmically with increasing ionic strength, suggesting that the aqueous solubility of the ffa is an important determinant of its dissociation rate from L-FABP. Fatty acid binding and the relative partition of n-(9-anthroloxy) ffa to L-FABP as compared with phospholipid membranes both decrease as pH decreases, indicating that ionized but not protonated ffa bind to L-FABP. The rate of ffa transfer from L-FABP to membranes increases approximately 4-fold with increasing pH, suggesting that ionization of the ffa carboxyl group is also an important determinant of the transfer process. Analysis of the dependence of the transfer rate on temperature demonstrates that the delta G++ of the activated state for ffa transfer arises from both enthalpic and entropic processes. These studies demonstrate that the rate of transfer of long chain ffa from L-FABP to membranes is substantially affected by aqueous phase variables as well as properties of the ffa ligand itself.

Animals↗

PubMed1992

Sparganosis in the spinal canal with partial block: an uncommon infection.

A case of rare intraspinal sparganosis treated by surgical excision is described. In this 59-year-old male with paraparesis and voiding problem, an intradural mass was noted on myelogram. Magnetic resonance (MR) and computed tomographic appearance of spinal and associated cerebral lesion are illustrated and possible route of migration discussed. This represents, to our knowledge, the first MRI demonstration of intraspinal sparganosis reported in the literature.

Humans↗

PubMed1992

Dietary glucose and fat attenuate effects of adrenalectomy on energy balance in ob/ob mice.

The body energy balance response of ob/ob mice to adrenalectomy is diet dependent. Diets varying in source of carbohydrate (starch, glucose or fructose), fat to starch ratio, or fat to glucose ratio were fed to determine influences on energy balance in female adrenalectomized ob/ob mice. Adrenalectomy lowered food intake in all ob/ob mice to values comparable to those of lean mice independent of diet, but the percentage of dietary energy retained as body energy in adrenalectomized ob/ob mice was lowered to values comparable to those of lean mice only in mice fed starch or fructose, not in mice fed glucose or fat. Consumption of either high glucose or high fat diets blocked about one-half the overall effect of adrenalectomy on energy balance in ob/ob mice. Hyperinsulinemia was associated with the high efficiency of energy retention observed in adrenalectomized ob/ob mice fed glucose, but high efficiency of energy retention occurred in adrenalectomized ob/ob mice fed high fat diets without concomitant hyperinsulinemia. Adrenalectomy-induced changes in brain weight and protein content, body protein content and plasma thyroid hormone concentrations in ob/ob mice were independent of diet consumption. Combined adrenalectomy-ovariectomy diminished, but did not eliminate, the diet-dependent influences on energy balance in ob/ob mice. In conclusion, dietary glucose and dietary fat both attenuate effects of adrenalectomy on energy balance in ob/ob mice by promoting high efficiencies of energy retention.

Administration, Oral↗

PubMed1992

Biological resurfacing of full-thickness defects in patellar articular cartilage of the rabbit. Investigation of autogenous periosteal grafts subjected to continuous passive motion.

We compared the effects of continuous passive motion with those of intermittent active motion on the results of the resurfacing with autogenous periosteal grafts of full-thickness defects on the articular surface of rabbit patellae. Of 45 rabbits with defects, 30 received grafts. Fifteen of these had continuous passive motion for two weeks and intermittent active motion for four weeks; the other 15 had intermittent active motion for six weeks. In 15 the defects were not grafted (control group) and they had intermittent active motion for six weeks. Ten more rabbits had a sham operation. Six weeks after surgery, the results were assessed by the gross appearance, histology, histochemistry, immunohistochemistry and electron microscopy. By all assessments the quality of neochondrogenesis produced by periosteal grafts was superior to that in ungrafted defects (p less than 0.05) and the results in continuous passive motion treated animals were superior to those in intermittent active motion treated animals (p less than 0.05). The periosteal grafts produced hyaline cartilage containing type II collagen but the organisation of its fibres was irregular.

Animals↗

PubMed1992

Effects of buthionine sulfoximine treatment on cellular glutathione levels and cytotoxicities of cisplatin, carboplatin and radiation in human stomach and ovarian cancer cell lines.

Chemotherapy failure remains a significant medical problem in the treatment of neoplastic disease and is thought to be due to many different factors including membrane transport, p-glycoprotein in multidrug resistance, glutathione and its related enzymes, topoisomerase II and DNA repair. Glutathione is a major constituent of non-protein thiol and participates in detoxification of chemotherapy and radiation. Thus, glutathione concentration is correlated with sensitivity to alkylating agents and radiation, and increased in resistant cell lines. Buthionine sulfoximine (BSO) is an inhibitor of glutathione biosynthesis and may increase cytotoxicities of alkylating agents, including melphalan and cisplatin, and radiation in sensitive and resistant cell lines. We studied effects on cellular glutathione levels and cytotoxicities of cisplatin, carboplatin and radiation by BSO treatment in human stomach cancer cell line (SNU-1) and ovarian cancer cell line (OVCAR-3). The results were as follow: 1) After BSO treatment of 1 mM and 2 mM for 2 days, the intracellular thiol concentration was depleted to 75.7% and 76.2% in SNU-1, and 74.1% and 63.0% in OVCAR-3, respectively. 2) The intracellular thiol concentration in SNU-1 was depleted to 33.4% after BSO 2 mM for only 2 hours incubation and 71.5% after small amount of BSO (0.02 mM) for 2 days. 3) The recovery of intracellular thiol concentration required more than 3 days after BSO removal. 4) BSO inhibited partially the growth of SNU-1 and OVCAR-3. 5) The cytotoxicities of cisplatin and carboplatin were markedly enhanced both in SNU-1 and OVCAR-3 by BSO treatment. 6) The cytotoxicities of radiation was increased in OVCAR-3 and SNU-1 by BSO treatment. Therefore, it is concluded that BSO can deplete effectively the intracellular thiol concentration and enhance the cytotoxicities of cisplatin, carboplatin and radiation.

Antimetabolites, Antineoplastic↗

PubMed1992

Overexpression of erbB-2 protein in gastric adenocarcinoma--a potential role in therapeutic response to adjuvant 5-FU-doxorubicin regimen.

In order to study the influence of erbB-2 protein overexpression on outcome of patients with gastric cancer after attempted curative resection with or without adjuvant chemotherapy, paraffin embedded sections from 109 cases of primary gastric cancer with defined treatments have been immunostained for erbB-2 protein in a retrospective study. Thirty four cases (31%) showed strong membrane staining of tumor cells. erbB-2 overexpression did not show significant effect on outcome when all patients were considered. However, erbB-2 overexpression was an indicator for poor disease free survival (p = 0.0474), local relapse free survival (p = 0.0293), and overall survival (p = 0.0310) of the patients treated with surgery only (N = 51), while it did not show any effect on outcome of patients treated with 5-FU plus Doxorubicin (FA) as adjuvant chemotherapy (N = 58). Furthermore, the apparent therapeutic benefit from FA regimen was restricted to patients with erbB-2 positive tumors. Combined predictive value of erbB-2 and FA regimen was found to be significant in predicting local relapse in multivariate analysis (p = 0.0439). The data suggests that erbB-2 may be associated with an improved response to FA regimen and that erbB-2 should be included as a potential confounding variable in the analysis of the data from the clinical trials for gastric cancer.

Adenocarcinoma↗

PubMed1992

Allogeneic bone marrow transplantation for the patients with hemopoietic stem cell disorders: CUMC experience.

Bone marrow transplantation from an HLA-identical sibling is increasingly used as a curative therapy for patients with hemopoietic stem cell disorders including acute leukemia, chronic myelogenous leukemia and severe aplastic anemia. Between March 1983 and March 1991, we performed 86 cases of allogeneic bone marrow transplantation (BMT) for the patients with hemopoietic stem cell disorders: 25 acute myelogenous leukemia (AML); 15 acute lymphoblastic leukemia (ALL); 20 chronic myelogenous leukemia (CML); and 26 severe aplastic anemia (SAA). Ten out of 25 AML are in disease free survival (DFS). The causes of death were recurrence of leukemia (12), acute GVHD (3), sepsis (1) and veno-occlusive disease (1). Nine of 15 ALL are in unmaintained remission. Thirteen out of 20 CML are in DFS. Among 26 SAA, 21 are enjoying DFS, but 1 died of engraftment failure, 3 of graft rejection followed by cytomegalovirus (1) and aspergillus pneumonia (1). Comparing the survival between standard [less than or equal to CR1: 9/14 (64%)] and high risk [greater than or equal to CR1: 1/11 (9%)] AML, our data suggest that preparative regimen for high risk AML was not potent enough to eradicate the minimal residual disease in advanced AML. Although our cases are limited and the follow-up period is short, our result of ALL [overall: CCR (60%), standard risk (adult less than or equal to CR1, children less than or equal to CR2; 8/11 (73%) and high risk; 1/4 (25%)] and CML [overall: 65%, CP; 9/10 (90%), AP; 4/6 (67%), BP; 0/4 (0%)] are optimistic. It is of our interest that the incidence of death related with IP (1/33: 3%) and with AGVHD 94/33: 12%) were much less than that of other's observation but the explanation for this still remains to be clear.

Acute Disease↗

PubMed1991

PDGF stimulation of inositol phospholipid hydrolysis requires PLC-gamma 1 phosphorylation on tyrosine residues 783 and 1254.

PDGF binding to its receptor promotes the association with and stimulates the phosphorylation of PLC-gamma 1 at tyrosine and serine residues. Also, PDGF induces an increase in the hydrolysis of inositol phospholipids by PLC. How PDGF activates PLC was investigated by substituting phenylalanine for tyrosine at PLC-gamma 1 phosphorylation sites 771, 783, and 1254 and expressing the mutant enzymes in NIH 3T3 cells. Phenylalanine substitution at Tyr-783 completely blocked the activation of PLC by PDGF, whereas mutation at Try-1254 inhibited and mutation at Tyr-771 enhanced the response. Like the wild type, PLC-gamma 1 substituted with phenylalanine at Tyr-783 became associated with the PDGF receptor and underwent phosphorylation at serine residues in response to PDGF. These results suggest that PLC-gamma 1 is the PLC isozyme that mediates PDGF-induced inositol phospholipid hydrolysis, that phosphorylation on Tyr-783 is essential for PLC-gamma 1 activation. These results provide direct evidence that growth factor receptors activate the function of intracellular protein by tyrosine phosphorylation.

Animals↗

PubMed1991

Free groin flaps in microsurgical reconstruction of the extremity.

The authors performed free groin flap transplantation in 36 patients with extensive soft-tissue injury of the extremities. In each case, the vascular anatomy of the groin flap was analyzed during the operation. The anatomic classification of the superficial circumflex iliac artery according to its origin was as follows: a common origin with the superficial inferior epigastric artery in 15 cases (39.5 percent); an isolated origin and absent superficial inferior epigastric artery in 14 cases (36.8 percent), a separate origin in three cases (7.9 percent), and an origin from the profunda femoral artery in six cases (15.8 percent). These results are similar to those reported previously. The overall success rate was 72.2 percent. The success rate was better in the upper extremity (100.0 percent) than in the lower extremity (65.5 percent). Free vascularized groin flap transplantation is a suitable procedure for the one-stage reconstruction of severe soft-tissue injury, especially in the upper extremity.

Arm Injuries↗

PubMed1991

Metabolic deviation of mouse liver by RhIL1-alpha or RhTNF/cachectin.

In this work deviation of liver metabolism by cytokines, especially recombinant human interleukin 1-alpha (rhIL1-alpha), was investigated. Administration of rhIL1-alpha or recombinant human tumor necrosis factor (rhTNF/cachectin) to normal mice resulted in rapid, dose-dependent induction of high liver ornithine decarboxylase (ODC) activity. The effects of these cytokines on liver ODC were not indirect effects mediated by eicosanoids. The induction of liver ODC by rhIL1-alpha was at least partly a direct effect on hepatocytes, and was due to increase in de novo synthesis of the enzyme protein after increase in ODC mRNA. No specific protein was required for increase in the level of ODC-mRNA. On IL1 treatment, actinomycin D caused superinduction of liver ODC, which was at least partly due to increased stability of the ODC enzyme, because actinomycin D doubled the apparent half-life (from 50 to 95 min). Daily administration of 2 x 10(3) U of rhIL1-alpha to mice for 3 days also caused decrease in the level of the differentiated type of pyruvate kinase isozyme (PK-L) and marked increase in that of the prototype isozyme (PK-M2) in the liver, but did not cause significant change in the isozyme patterns of the kidney, thymus, and spleen. RhIL1-alpha also induced hypertrophy of the spleen. These results indicate that rhIL1-alpha causes metabolic deviation of the liver similar to that in tumor-bearing hosts.

Animals↗

PubMed1991

Mechanism of metabolic abnormality of thyroid hormones in Walker 256 carcinosarcoma-bearing rats.

We examined the mechanism of abnormality of thyroid hormone metabolism in Walker 256 carcinosarcoma-bearing rats. The serum levels of thyroxine (T4), 3,5,3'-triiodothyronine (T3) and thyroid-stimulating hormone (TSH), and the responses of serum T4 and T3 to exogenous TSH in tumor-bearing rats on day 14 after inoculation of tumor cells were significantly less than those in pair-fed control (PFC) rats, suggesting that the metabolic abnormality of thyroid hormones may be caused by disorder of both peripheral and central functions, and that a certain tumor-derived factor may be involved in this abnormality. An active factor responsible for the metabolic abnormality was found in soluble cytosol fraction (SF) of the tumor cells. Administration of the SF to normal rats significantly reduced their serum T4 and T3 concentrations, liver 5'-deiodinase (5'-DI) activity, responsiveness of the thyroid gland to TSH and food intake compared with those of PFC rats, but, unlike the tumor, did not reduce the serum TSH level. This biologically active factor in the SF was found to be a heat-labile protein and specific to the tumor. It was tentatively named serum thyroid hormone reducing factor (STRF). STRF was partially purified from the SF by ammonium sulfate fractionation and DEAE-cellulose chromatography. Partially purified STRF preparation significantly diminished the serum T4 and T3 concentrations and liver 5'-DI activity and food intake of normal rats compared with those of PFC rats, mimicking the changes associated with the tumor in tumor-bearing animals. These results suggested that abnormality of thyroid hormone metabolism in tumor-bearing animals may partly be caused by STRF-mediated modulation at peripheral and thyroid gland levels. Whether STRF actually induces anorexia remains to be clarified.

Animals↗

PubMed1991

Purification of ornithine decarboxylase-inducing factor from cell-free ascites fluid of Ehrlich ascites tumor and its characteristics.

The ornithine decarboxylase-inducing factor (ODC factor) was purified about 1,000-fold in 42% yield from the ascites fluids of an Ehrlich ascites tumor by a combination of centrifugation and concanavalin A (ConA) treatment. A single ip injection of 0.5 micrograms of the purified factor per mouse resulted in half-maximum induction of liver ODC. The factor was found to be a trypsin- and chymotrypsin-resistant, acidic glycoprotein (pI about 4.43) with a minimum molecular weight of about 70 kilodaltons, containing a disulfide bond(s) in its functional domain. It did not react with ConA. This factor induced retrodifferentiation of liver function, causing a marked increase of prototype M2 isozyme of pyruvate kinase. It reduced liver catalase activity, and also modified thyroid hormone metabolism, reducing the serum levels of T4 and T3. These results suggest that the ODC factor is multifunctional and induces many of the changes observed in a tumor-bearing host.

Animals↗

PubMed1991

A case of intrapericardial extralobar pulmonary sequestration--first case in Korea.

Extralobar pulmonary sequestration, known as accessory lung, is a rare congenital anomaly and intrapericardial lung sequestration is extremely rare. To the best of our knowledge, only four reported cases were intrapericardial. We report a case with intrapericardial extralobar pulmonary sequestration confirmed by operation and morphologic basis.

Adult↗

PubMed1991

Characterization and structure of the cellulase gene of Bacillus subtilis BSE616.

The Bacillus subtilis carboxymethyl cellulase (CMCase) gene originally cloned on a 3.2-kb PstI DNA fragment has been localized in a 1.5-kb Sau3AI fragment by a series of subclonings into plasmid pUC19. During the process the promoter region and Shine-Dalgarno (SD) sequence were deleted, but the 1.5-kb insert was shown to direct the synthesis of CMCase in scherichia coli to a high level, probably with the aid of lac promoter. We analyzed the complete nucleotide sequence of the CMCase gene. The CMCase gene is 1500-bp long, encoding a polypeptide of 499 amino acids and a stop codon. The putative "-35" region (TAGACA), "-10" region (TACAAT), and ribosome binding site (RBS) (AAGGAGG) have also been identified in the 5' flanking region. Comparison of the nucleotide sequence to three other published endo-beta-1,4-glucanase genes of B. subtilis strains shows that these sequences share very strong homology. It seems that the cellulase genes have been derived from a common ancestor by spontaneous mutation. The probability of carboxy-terminal processing of the CMCase protein is also discussed.

Amino Acid Sequence↗

PubMed1991

The potential for regeneration of articular cartilage in defects created by chondral shaving and subchondral abrasion. An experimental investigation in rabbits.

Animal models for chondral shaving and subchondral abrasion were created to resolve the controversy about the nature of the repair tissue after these procedures and to determine the effect of continuous passive motion on the quality of the repair tissue. Chondral shaving was performed on the patella in forty adolescent rabbits, and subchondral abrasion was performed on the patella in another forty rabbits. In both procedures, a three-millimeter-diameter defect was created. After the operation, twenty animals from each group were allowed intermittent active motion; the remainder were treated by continuous passive motion for two weeks, followed by intermittent active motion. Half of the animals from each group were killed at four weeks and the other half, at twelve weeks. There was no evidence of repair tissue in the defects at either four or twelve weeks after chondral shaving, regardless of the postoperative treatment. The remaining underlying cartilage, however, had degenerated. After abrasion of subchondral bone, the defects in animals that were treated with only intermittent active motion healed at twelve weeks, although the quality of the repair tissue varied. All ten of the animals that were treated with continuous passive motion, however, had mature, hyaline-like cartilage as the predominant repair tissue at twelve weeks, compared with six of the ten animals that were treated with intermittent active motion (p less than 0.05). We concluded that, in this model, partial-thickness defects created by chondral shaving do not heal; rather, the remaining underlying cartilage degenerates. Full-thickness defects created by subchondral abrasion can heal by regeneration of hyaline-like cartilage. Such healing is enhanced by continuous passive motion for two weeks postoperatively.

Animals↗

PubMed1990

The effect of phytochrome action on the activity of cytosolic cholinesterase in oat cells.

Cholinesterases in the oat cell were found to be distributed in the cell wall (50%) and cytoplasm (42%). Activity of the cytosolic enzyme was inhibited about 80% by 1 mM Ca2+. The enzyme activity was also inhibited by Mn2+, but no inhibition by Mg2+ was observed. Effects of red light and calcium ion on the enzyme activity were investigated in vivo to confirm the involvement of phytochrome action in the regulation process of this enzyme via Ca2+. It was observed that inhibition by red light only occurs when external Ca2+ existed in the cell medium. Based on a previous report (8) that red light stimulates the influx of Ca2+ into the cytosol of oat cell, inhibition of the enzyme activity by irradiation of red light can be suggested to occur via the influx of Ca2+.

Calcium↗

PubMed1990

Molecular cloning and expression of a complementary DNA for inositol 1,4,5-trisphosphate 3-kinase.

A complementary DNA (cDNA) clone that encodes inositol 1,4,5-trisphosphate 3-kinase was isolated from a rat brain cDNA expression library with the use of monoclonal antibodies. This clone had an open reading frame that would direct the synthesis of a protein consisting of 449 amino acids and with a molecular mass of 49,853 daltons. The putative protein revealed a potential calmodulin-binding site and six regions with amino acid compositions (PEST regions) common to proteins that are susceptible to calpain. Expression of the cDNA in COS cells resulted in an approximately 150-fold increase in inositol 1,4,5-trisphosphate 3-kinase activity of these cells.

Amino Acid Sequence↗