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Biomedical subjects

H G Kim

Publications and source records attributed to H G Kim.

At least 19 recordsLinked to original sources

PLC gamma contributes to metastasis of in situ-occurring mammary and prostate tumors.

Phospholipase C-gamma (PLCgamma) has been implicated in tumor cell motility required for invasiveness and metastasis. Diminished tumor dissemination has been demonstrated in xenograft models, but studies in naturally-occurring tumors are lacking, having been limited by the timing of the interventions. Therefore, we generated mice that express a doxycycline (DOX)-inducible dominant-negative fragment of PLCgamma, PLCz; this approach avoids the in utero lethality caused by the absence of PLCgamma. As we targeted two de novo-occurring carcinomas of the mammary (MMTV-driven polyoma middle T antigen model, PyVmT) and prostate (TRAMP model) glands, we limited expression to these epithelial cells by driving DOX transactivator from the prostatein C3 promoter. This avoids the confounding variable of potentially abrogating motility in stromal and endothelial cells. These mice developed normally in the presence of DOX, except for limited mammary development if treated before 6 weeks and immaturity of the prostate gland if treated before 2 weeks of age. DOX-mediated induction of PLCz from age 8 to 16 weeks in PyVmT mice decreased the number of lung metastases by >10-fold (P<0.06) without a detectable effect on in situ tumor cell proliferation or tumor size. Lung metastases were also significantly decreased in the TRAMP model in which the mice expressed the PLCz fragment (P<0.05). DOX treatment itself had no effect on tumor size or metastasis in control mice, nor did it affect tumor dissemination in nontransgenic littermates. In conclusion, abrogation of the PLCgamma signaling pathway can limit the metastatic potential of carcinomas.

Animals↗

Growth-inhibiting activity of active component isolated from Terminalia chebula fruits against intestinal bacteria.

The growth-inhibitory activity of materials derived from the fruit of Terminalia chebula was evaluated against six intestinal bacteria by means of an impregnated paper disk agar diffusion method. The butanol fraction of T. chebula extract had profound growth-inhibitory activity at a concentration of 5 mg per disk. The biologically active component isolated from the T. chebula fruits was identified with a variety of spectroscopic analyses as ethanedioic acid. The growth responses varied in accordance with the bacterial strain, chemical, and dosage tested. In a test with concentrations of 2 and 1 mg per disk, ethanedioic acid had strong and moderate inhibitory activity against Clostridium perfringens and Escherichia coli, respectively, with no associated adverse effects on the growth of the four tested lactic acid-producing bacteria. Ellagic acid derived from T. chebula fruits exerted a potent inhibitory effect against C. perfringens and E. coli, but little or no inhibition was observed with treatments of behenic acid, P-caryophyllene, eugenol, isoquercitrin, oleic acid, ca-phellandrene, 3-sitosterol, stearic acid, a-terpinene, terpinen-4-ol, terpinolene, or triacontanoic acid. These results may be an indication of at least one of the pharmacological properties of T. chebula fruits.

Clostridium perfringens↗

Antenatal psychiatric illness and adequacy of prenatal care in an ethnically diverse inner-city obstetric population.

OBJECTIVE: This study assessed the prevalence of antenatal psychiatric illness in low-income, ethnically diverse patients in an urban obstetric clinic and examined associations between positive psychiatric screens and inadequate utilization of prenatal care. METHODS: Bilingual research assistants administered the Primary Care Evaluation of Mental Disorders Patient Health Questionnaire and the Mood Disorder Questionnaire to 154 English- and Spanish-speaking pregnant patients attending routine prenatal visits. We assessed associations between patient characteristics, current and past psychiatric diagnoses, and utilization of prenatal care. RESULTS: Forty-five (29%) women screened positive for criteria for current psychiatric disorders with the highest rates for major or minor depression (26%) and anxiety disorders (10%). Inadequate prenatal care utilization was significantly associated with past psychiatric history and domestic abuse in the last year, but not with current psychiatric diagnosis, alcohol abuse, age, primiparity, marital status, receipt of government assistance, or unplanned pregnancy. Even after adjustment for possible confounding risk factors (e.g. past substance abuse, single marital status, unstable housing, education less than high school, and having other children), past psychiatric history was still significantly associated with inadequate prenatal care utilization and delayed initiation of care. CONCLUSIONS: A high percentage of disadvantaged pregnant women meet screening criteria for psychiatric disorders when screened during routine prenatal visits. Screening for past psychiatric history in routine prenatal visits could identify patients at risk for inadequate utilization of prenatal care.

Adult↗

Factors affecting the long-term patency of crossover femorofemoral bypass graft.

OBJECTIVES: To determine the factors affecting long-term patency of crossover femorofemoral bypass (FFB) graft. DESIGN: A retrospective clinical study of a prospectively registered database. MATERIALS: Two hundred and sixteen FFBs performed for 192 patients with atherosclerotic iliac occlusive disease. METHODS: The clinical and surgical variables influencing graft patency were assessed with log-rank test and Cox's proportional hazard analysis. RESULTS: The primary patency rates of all FFB grafts at 3 and 5 years were 73+/-4 and 65+/-5%, respectively. By multivariate analysis, hypertension (Odds ratio 2.8, P=0.002) and critical ischemia (Odds ratio 0.42, P=0.01) significantly (P<.05) influenced long-term patency of FFB grafts. CONCLUSION: The long-term patency of FFB grafts was not affected by procedural modifications. Graft patency was inferior in patients with severe lower limb ischemia but superior in patients with hypertension. Further study is required to clarify the mechanism of an unexpected beneficial effect of hypertension on FFB graft patency.

Aged↗

Comparison of the immunogenicity of recombinant VP2 and VP3 of infectious pancreatic necrosis virus and marine birnavirus.

Recombinant proteins of truncated viral protein-2 (VP2) (aa 79-359) and VP3 of infectious pancreatic necrosis virus (IPNV) and marine birnavirus (MABV) were expressed in E. coli and their immunogenicities in fish were investigated. The recombinant proteins from IPNV were used to immunize rainbow trout and those from MABV to immunize flounder. The sera from the immunized fishes were assayed for antibody by ELISA and a neutralization test. Both the recombinant VP2 and VP3 produced antibodies in fish but the VP3 antibody titers were higher than that of the VP2 of IPNV and MABV. These results indicate that the recombinant VP3 is more immunogenic than the recombinant VP2.

Animals↗

Surgical treatment of post-traumatic stiffness of the elbow.

Surgical release of the elbow was performed in 27 patients with post-traumatic stiffness at a mean of 14.5 months after the initial injury. The outcome was related to whether there had been heterotopic ossification, which had occurred in 18 elbows and to whether, if there had been a fracture, it had involved the articular surface, which had occurred in 13 elbows. The final range of movement and the ratio of desired gain in each group were compared at a mean follow-up period of 22.5 months (12 to 43). The arc of movement of the elbow improved in all patients after the operation. The mean final arc was 110 degrees in those with heterotopic ossification and 86 degrees in those without (p = 0.001). The ratios of desired gain were significantly higher in patients with heterotopic ossification (88.2% vs 54.9%; p < 0.001). There was no significant difference in relation to involvement of the articular surface. Careful assessment of the cause of stiffness is important in order to achieve a satisfactory result from surgery for post-traumatic stiffness of the elbow.

Adolescent↗

The microbial community analysis of a 5-stage BNR process with step feed system.

The microbial communities of 5-stage BNR activated sludge samples were analyzed using fluorescence in-situ hybridization (FISH) and 16S rDNA characterization. The total cell numbers of each reactor were from 2.36 x 10(9) cells/ml to 2.83 x 10(9) cells/ml. From 56.5% to 62.0% of total DAPI cell counts were hybridized to the most bacterial specific probe EUB 338. Among them, beta-proteobacteria were most dominant in each tank. The number of phosphate accumulating organisms (PAOs) was almost 50% of the total cell number in anoxic-1 tank, and these results indicate that this process has a high content of denitrifying phosphorus accumulating organisms (dPAOs). In contrast with FISH, 16S rDNA analysis showed that dominant groups were the Cytophaga-Flavobacterium group and high G+C% gram-positive bacteria, which were determined as PAOs in anoxic-1 tank. The beta subclass Proteobacteria did not accumulate a large amount of polyphosphate. The overall results indicate that high G+C% gram-positive bacteria and the Cytophaga-Flavobacterium group might play a key role as dPAOs in this process.

Bioreactors↗

Knowledge and attitudes of Korean parents towards their son's circumcision: a nationwide questionnaire study.

OBJECTIVE: To evaluate knowledge about the foreskin and circumcision, and to understand the attitudes of parents to circumcision in Korea, where circumcision in childhood is widely practised with no particular religious or medical background. SUBJECTS AND METHODS: A nationwide study involving questionnaires was conducted on 5500 parents with at least one son attending elementary school. Responses were obtained from one of the parents. RESULTS: The response rate was 76.1% (4183); circumcision was most common in boys when aged 11 years, followed by neonatal circumcision. Of the parents, 91.3% believed that circumcision is necessary, while 2.1% believed it to be unnecessary. The principal reasons given for circumcision were 'to improve penile hygiene' (82.4%), followed by 'to improve future sexual potency' (7.5%). Among those who did not believe circumcision to be necessary, the most common reason was the expectation of spontaneous retraction of the prepuce with age (55.1%). Most (88.4%) of the parents believed that smegma is not a clean material, and is infected by microorganisms. Most parents (80.6%) thought that circumcision would prevent genital tract infection of the future spouse. Peer pressure was one of the most influential factors in deciding upon circumcision; 41.9% of the parents were anxious that their child might be ridiculed by his peer group unless he was circumcised, while 27.4% of the parents believed that their child might be ridiculed if he was circumcised. Mothers were more positive about circumcision than fathers (P < 0.05). Parents with a higher education and higher socio-economic status were also more positive about circumcision (P < 0.05). Mothers were prone to emphasize improved sexual potency (P < 0.05). There was no significant difference in response between urban and rural areas. CONCLUSION: This study indicates that common beliefs held by parents about the prepuce or circumcision differ significantly from current medical knowledge, and these beliefs have a major influence on the practice of circumcision in Korea. More clinical research on the natural history of the foreskin is needed, and it is critical that both children and parents are informed about the potential benefits and disadvantages of circumcision.

Adolescent↗

Intraoral mandibular distraction osteogenesis in facial asymmetry patients with unilateral temporomandibular joint bony ankylosis.

Gap arthroplasty and costochondral rib bone graft are commonly performed by oral and maxillofacial surgeons to reconstruct the temporomandibular joint with ankylosis. However, unpredictable and unsatisfactory results such as re-ankylosis, growth disturbance, and facial asymmetry often occur. Even if the costochondral graft is successful, donor-site morbidity is inevitable. More recently, surgeons have become interested in distraction osteogenesis as a means of temporomandibular joint reconstruction. This case series presents the results of intraoral mandibular distraction osteogenesis and gap arthroplasty in two patients with facial asymmetry and unilateral temporomandibular joint bony ankylosis. Both patients had experienced failed gap arthroplasty and costochondral graft for the reconstruction of the temporomandibular joint. Distraction osteogenesis with gap arthroplasty proved successful in these two patients with follow-up of longer than 2 years.

Adolescent↗

Characterization and regulation of glutathione S-transferase gene from Schizosaccharomyces pombe.

A glutathione S-transferase (GST) gene has been cloned from Schizosaccharomyces pombe for the first time. The nucleotide sequence determined was found to contain 2030 base pairs including an open reading frame of 229 amino acids that would encode a protein of a molecular mass of 27017 Da. The cloned GST gene was expressed and was found to function in S. pombe, Saccharomyces cerevisiae, and Escherichia coli. The plasmid pGT207 encoding the S. pombe GST gene appeared to be able to accelerate the growth of a wild type S. pombe culture. In a culture of S. pombe containing plasmid pGT207, the growth was inhibited less by mercuric chloride than in a culture with vector alone. The 1088 bp region upstream from the GST gene as well as the region encoding the N-terminal 14 amino acids was transferred into the promoterless beta-galactosidase gene of plasmid YEp357R to yield the fusion plasmid pYSH2000. beta-Galactosidase synthesis was induced by cadmium chloride, mercuric chloride, hydrogen peroxide, and menadione. It was also induced by high temperature. These results suggest that the cloned S. pombe GST gene is involved in the oxidative stress response.

Amino Acid Sequence↗

Functional hemizygosity of PAFAH1B3 due to a PAFAH1B3-CLK2 fusion gene in a female with mental retardation, ataxia and atrophy of the brain.

We report on the molecular characterization of a translocation t(1;19)(q21.3;q13.2) in a female with mental retardation, ataxia and atrophy of the brain. Sequence analysis of the breakpoints revealed an ALU:-repeat-mediated mechanism of recombination that led to truncation of two genes: the kinase CLK2 and PAFAH1B3, the gene product of which interacts with LIS1 as part of a heterotrimeric G protein complex PAF-AH1B. In addition, two reciprocal fusion genes are present. One expressed fusion gene encodes the first 136 amino acids of PAFAH1B3 followed by the complete CLK2 protein. Truncated PAFAH1B3 protein lost its potential to interact with LIS1 whereas CLK2 activity was conserved within the fusion protein. These data emphasize the importance of PAF-AH1B in brain development and functioning and demonstrate the first fusion gene apparently not associated with cancer.

Abnormalities, Multiple↗

Inhibition of cytosolic phospholipase A2 by annexin I. Specific interaction model and mapping of the interaction site.

Annexins (ANXs) display regulatory functions in diverse cellular processes, including inflammation, immune suppression, and membrane fusion. However, the exact biological functions of ANXs still remain obscure. Inhibition of phospholipase A(2) (PLA(2)) by ANX-I, a 346-amino acid protein, has been observed in studies with various forms of PLA(2). "Substrate depletion" and "specific interaction" have been proposed for the mechanism of PLA(2) inhibition by ANX-I. Previously, we proposed a specific interaction model for inhibition of a 100-kDa porcine spleen cytosolic form of PLA(2) (cPLA(2)) by ANX-I (Kim, K. M., Kim, D. K., Park, Y. M., and Na, D. S. (1994) FEBS Lett. 343, 251-255). Herein, we present an analysis of the inhibition mechanism of cPLA(2) by ANX-I in detail using ANX-I and its deletion mutants. Deletion mutants were produced in Escherichia coli, and inhibition of cPLA(2) activity was determined. The deletion mutant ANX-I-(1-274), containing the N terminus to amino acid 274, exhibited no cPLA(2) inhibitory activity, whereas the deletion mutant ANX-I-(275-346), containing amino acid 275 to the C terminus, retained full activity. The protein-protein interaction between cPLA(2) and ANX-I was examined using the deletion mutants by immunoprecipitation and mammalian two-hybrid methods. Full-length ANX-I and ANX-I-(275-346) interacted with the calcium-dependent lipid-binding domain of cPLA(2). ANX-I-(1-274) did not interact with cPLA(2). Immunoprecipitation of A549 cell lysate with anti-ANX-I antibody resulted in coprecipitation of cPLA(2). These results are consistent with the specific interaction mechanism rather than the substrate depletion model. ANX-I may function as a negative regulator of cPLA(2) in cellular signal transduction.

Animals↗

The short head of the biceps femoris as a monitor for the free lateral thigh flap in pharyngoesophageal reconstruction.

Free flaps are frequently used to reconstruct the defect following radical resection of pharyngoesophageal malignancy but postoperative monitoring of buried flaps is difficult. We have designed a monitoring-muscle flap using the short head of the biceps femoris muscle when using a free lateral thigh flap. The third and fourth perforators of the profunda femoris artery, the main vascular pedicle of the lateral thigh flap, pass through the short head of the biceps femoris. Partial excision of the short head of the biceps femoris muscle does not result in any functional disturbance of the leg, and the viability of the buried lateral thigh flap can be monitored by observing the exposed muscle through a small window in the neck. Between April and October 1998 five patients underwent pharyngoesophageal reconstruction by this method. The short head of the biceps femoris was used to monitor the main flap in three patients and to obliterate the dead space after neck dissection in two patients. There were no recipient-site complications such as fistula or infection and no disturbance of thigh function.

Aged↗

Hypocholesterolemic effect of bile acid sulfonate analogs in hamsters.

We studied the effects of bile acid sulfonate analogs, namely, 3alpha,7alpha,12alpha-trihydroxy-5beta-cholane-24-sulfonate (C-sul), 3alpha,7alpha-dihydroxy-5beta-cholane-24-sulfonate (CDC-sul), and 3alpha,7beta-dihydroxy-5beta-cholane-24-sulfonate (UDC-sul), on serum and liver cholesterol levels, cholesterol 7alpha-hydroxylase activity, and biliary bile acid composition in hamsters fed cholesterol. Of the three analogs studied, UDC-sul slightly but significantly decreased free, esterified, and total cholesterol concentrations in the serum. UDC-sul and CDC-sul reduced liver total cholesterol levels by 25% and 18%, respectively, particularly in the esterified cholesterol fraction. Analysis of biliary bile acids showed the presence of the administered analogs, indicating that sulfonate analogs efficiently participate in enterohepatic cycling. The proportion of cholic acid was increased in all groups fed sulfonate analogs, but the ratio of glycine to taurine conjugated bile acids (G/T) was elevated only in UDC-sul feeding hamsters. There was no significant change in cholesterol 7alpha-hydroxylase activity in hamsters fed C-sul or CDC-sul, while UDC-sul slightly stimulated the enzyme activity compared to the control. The UDC-sul induced decrease in serum and liver cholesterol concentrations may be secondary to enhanced bile acid synthesis. This is supported by the increased cholesterol 7alpha-hydroxylase activity and elevated G/T ratio in biliary bile acids observed following UDC-sul administration.

Animals↗

A case of torsade de pointes associated with hypopituitarism due to hemorrhagic fever with renal syndrome.

We describe a 51-yr-old man presenting with syncope due to torsade de pointes. The torsade de pointes was refractory to conventional medical therapy, including infusion of isoproterenol, MgSO4, potassium, lidocaine, and amiodarone. His past history, physical findings, and hormone study confirmed that QT prolongation was caused by anterior hypopituitarism that developed as a sequela of hemorrhagic fever with renal syndrome. The long QT interval with deep inverted T wave was completely normalized 4 weeks after starting steroid and thyroid hormone replacement. Hormonal disorders should be considered as a cause of torsade de pointes, because this life-threatening arrhythmia can be treated by replacing the missing hormone.

Hemorrhagic Fever with Renal Syndrome↗

Cloning, expression and regulation of Schizosaccharomyces pombe gene encoding thioltransferase.

The genomic DNA encoding thioltransferase was isolated from Schizosaccharomyces pombe using the polymerase chain reaction. The amplified DNA fragment was confirmed by Southern hybridization, completely digested with HindIII and BamHI, and then ligated into the yeast-Escherichia coli shuttle vector pRS316, which resulted in plasmid pEH1. The insert of plasmid pEH1 was transferred into the multi-copy vector YEp357 to generate plasmid pYEH1. The determined nucleotide sequence harbors an open reading frame consisting of four exons and three introns, which encodes a polypeptide of 101 amino acids with a molecular mass of 11261 Da. Thioltransferase activity was increased 1.6-fold in Saccharomyces cerevisiae containing plasmid pYEH1, and 1.8- and 2.7-fold in S. pombe containing plasmid pEH1 and pYEH1, respectively. The upstream sequence and the region encoding the N-terminal six amino acids were fused into promoterless beta-galactosidase gene of the shuttle vector YEp357R to generate the fusion plasmid pYEHR1. Synthesis of beta-galactosidase from the fusion plasmid was found to be enhanced by zinc and NO-generating S-nitroso-N-acetylpenicillamine.

Amino Acid Sequence↗

Angiopoietin-1 induces endothelial cell sprouting through the activation of focal adhesion kinase and plasmin secretion.

Angiopoietin-1 (Ang1) is a strong inducer of endothelial cell sprouting, which is a first step in both angiogenesis and neovascularization. We examined the mechanisms underlying Ang1-induced cell sprouting using porcine pulmonary artery endothelial cells. Ang1 induced the nondirectional and directional migration of endothelial cells mediated through the Tie2 but not the Tie1 receptor. Ang1 induced tyrosine phosphorylation of p125(FAK), and this phosphorylation was dependent on phosphatidylinositol (PI) 3'-kinase activity. Ang1 induced the secretion of plasmin and matrix metalloproteinase-2 (MMP-2), which is inhibited by PI 3'-kinase inhibitors. Ang1 also induced the secretion of small amounts of proMMP-3 and proMMP-9 but not proMMP-1. Ang1 suppressed the secretion of tissue inhibitor of metalloproteinase-2 (TIMP-2), but not of TIMP-1. Addition of alpha(2)-antiplasmin, a combination of TIMP-1 and TIMP-2, or PI 3'-kinase inhibitors inhibited Ang1-induced sprouting activity. Therefore, Ang1-induced sprouting activity in endothelial cells may be accomplished by cytoskeletal changes and secretion of proteinases and may be largely mediated through intracellular PI 3'-kinase activation.

Angiopoietin-1↗