Enhanced Expression of p53 and Suppression of PI3K/Akt/mTOR by Three Red Sea Algal Extracts: Insights on Their Composition by LC-MS-Based Metabolic Profiling and Molecular Networking

Brown algae comprise up to 2000 species with wide dissemination in temperate zones. A comprehensive untargeted metabolic profiling guided by molecular networking of three uninvestigated Red-Sea-derived brown algae, namely Sirophysalis trinodis, Polycladia myrica, and Turbinaria triquetra, led to the identification of over 115 metabolites categorized as glycerolipids, fatty acids, sterol lipids, sphingolipids, and phospholipids. The three algae exhibited low-to-moderate antioxidant capacity using DPPH and ABTS assays. Preliminary in vitro antiproliferative studies showed that the algal extracts displayed high cytotoxic activity against a panel of cancer cell lines. The most potent activity was recorded against MCF-7 with IC₅₀ values of 51.37 ± 1.19, 63.44 ± 1.13, and 59.70 ± 1.22 µg/mL for S. trinodis, P. myrica, and T. triquetra, respectively. The cytotoxicity of the algae was selective to MCF-7 without showing notable effects on the proliferation of normal human WISH cells. Morphological studies revealed that the algae caused cell shrinkage, increased cellular debris, triggered detachment, cell rounding, and cytoplasmic condensation in MCF-7 cancer cells. Mechanistic investigations using flow cytometry, qPCR, and Western blot showed that the algae induced apoptosis, initiated cell cycle arrest in the sub-G₀/G₁ phase, and inhibited the proliferation of cancer cells via increasing mRNA and protein expression of p53, while reducing the expression of PI3K, Akt, and mTOR.

N,N-Dimethyl-anthranilic Acid from Calvatia nipponica Mushroom Fruiting Bodies Induces Apoptotic Effects on MDA-MB-231 Human Breast Cancer Cells

Breast cancer ranks among the most prevalent malignancies affecting women worldwide, and apoptosis-targeting drugs are attractive candidates for the treatment of cancer. In the current study, we investigated the in vitro cytotoxicity of the mushroom Calvatia nipponica in human breast cancer cells (MDA-MB-231), identified potential antitumor compounds through bioactivity-guided isolation, and elucidated the antitumor, pro-apoptotic molecular mechanisms of the identified bioactive compounds. C. nipponica is edible when young, and it has been used as a food source as well as a traditional medicine in wound dressings. However, only a limited number of studies have reported its chemical composition and biological activities. In the screening test, the methanol extract of C. nipponica fruiting bodies exhibited cytotoxicity against MDA-MB-231 cells. Bioactivity-guided fractionation of the methanol (MeOH) extract and chemical investigation of the active fractions resulted in the isolation of fourteen compounds (1-14), including six alkaloids (1-3, 5, 7, and 8), two phenolic compounds (4 and 6), one fatty acid (9), and five steroids (10-14). The structures of the isolated compounds were determined using NMR spectroscopic methods, liquid chromatography-mass spectrometry, and comparison of data with previously reported values. The isolated compounds (1-14) were tested for cytotoxicity against MDA-MB-231 cells, where compound 1, i.e., N,N-dimethyl-anthranilic acid, exhibited the most significant cytotoxicity against MDA-MB-231 cells, with an IC₅₀ value of 90.28 ± 4.23 μM and apoptotic cell death of 56.01% ± 2.64% at 100 μM. Treatment with compound 1 resulted in an upregulation of protein levels, including cleaved caspase-8, cleaved poly (ADP-ribose) polymerase, Bcl-2-associated X protein (Bax), cleaved caspase-3, cleaved caspase-9, Bad, and Cytochrome c, but decreased the levels of B-cell lymphoma 2 (Bcl-2). Overall, these results indicate that N,N-dimethyl-anthranilic acid (1) may have anti-breast cancer activity and is probably involved in the induction of apoptosis mediated by extrinsic and intrinsic signaling pathways.

Methoxyflavones from Black Ginger (Kaempferia parviflora Wall. ex Baker) and their Inhibitory Effect on Melanogenesis in B16F10 Mouse Melanoma Cells

Kaempferia parviflora Wall. ex Baker (Zingiberaceae), commonly known as Thai ginseng or black ginger, is a tropical medicinal plant in many regions. It has been traditionally used to treat various ailments, including ulcers, dysentery, gout, allergies, abscesses, and osteoarthritis. As part of our ongoing phytochemical study aimed at discovering bioactive natural products, we investigated potential bioactive methoxyflavones from K. parviflora rhizomes. Phytochemical analysis aided by liquid chromatography-mass spectrometry (LC-MS) led to the isolation of six methoxyflavones (1-6) from the n-hexane fraction of the methanolic extract of K. parviflora rhizomes. The isolated compounds were structurally determined to be 3,7-dimethoxy-5-hydroxyflavone (1), 5-hydroxy-7-methoxyflavone (2), 7,4'-dimethylapigenin (3), 3,5,7-trimethoxyflavone (4), 3,7,4'-trimethylkaempferol (5), and 5-hydroxy-3,7,3',4'-tetramethoxyflavone (6), based on NMR data and LC-MS analysis. All of the isolated compounds were evaluated for their anti-melanogenic activities. In the activity assay, 7,4'-dimethylapigenin (3) and 3,5,7-trimethoxyflavone (4) significantly inhibited tyrosinase activity and melanin content in IBMX-stimulated B16F10 cells. In addition, structure-activity relationship analysis revealed that the methoxy group at C-5 in methoxyflavones is key to their anti-melanogenic activity. This study experimentally demonstrated that K. parviflora rhizomes are rich in methoxyflavones and can be a valuable natural resource for anti-melanogenic compounds.

Phytochemical Investigation of Marker Compounds from Indigenous Korean Salix Species and Their Antimicrobial Effects

Salix species, including willow trees, are distributed in the temperate regions of Asian countries, including South Korea. Willow trees are used to treat pain and inflammatory diseases. Due to the medicinal properties of willow trees, pharmacological studies of other Salix spp. have gained attention; however, only a few studies have investigated the phytochemicals of these species. As part of our ongoing natural product research to identify bioactive phytochemicals and elucidate their chemical structures from natural resources, we investigated the marker compounds from indigenous Korean Salix species, namely, Salix triandra, S. chaenomeloides, S. gracilistyla, S. koriyanagi, S. koreensis, S. pseudolasiogyne, S. caprea, and S. rorida. The ethanolic extract of each Salix sp. was investigated using high-performance liquid chromatography combined with thin-layer chromatography and liquid chromatography−mass spectrometry-based analysis, and marker compounds of each Salix sp. were isolated. The chemical structures of the marker compounds (1−8), 3-(4-hydroxyphenyl)propyl β-D-glucopyranoside (1), 2-O-acetylsalicin (2), 1-O-p-coumaroyl glucoside (3), picein (4), isograndidentatin B (5), 2′-O-acetylsalicortin (6), dihydromyricetin (7), and salicin (8) were elucidated via nuclear magnetic resonance spectroscopy and high-resolution liquid chromatography−mass spectrometry using ultrahigh-performance liquid chromatography coupled with a G6545B Q-TOF MS system with a dual electrospray ionization source. The identified marker compounds 1−8 were examined for their antimicrobial effects against plant pathogenic fungi and bacteria. Dihydromyricetin (7) exhibited antibacterial activity against Staphylococcus aureus, inducing 32.4% inhibition at a final concentration of 125 μg/mL with an MIC50 value of 250 μg/mL. Overall, this study isolated the marker compounds of S. triandra, S. chaenomeloides, S. gracilistyla, S. koriyanagi, S. koreensis, S. pseudolasiogyne, S. caprea, and S. rorida and identified the anti-Staphylococcus aureus bacterial compound dihydromyricetin.

Estrogenic Activity of 4-Hydroxy-Benzoic Acid from Acer tegmentosum via Estrogen Receptor α-Dependent Signaling Pathways

Acer tegmentosum, a deciduous tree belonging to Aceraceae, has been used in traditional oriental medicine for treating hepatic disorders, such as hepatitis, cirrhosis, and liver cancer. We evaluated the estrogen-like effects of A. tegmentosum using an estrogen receptor (ER)-positive breast cancer cell line, namely MCF-7, to identify potential phytoestrogens and found that an aqueous extract of A. tegmentosum promoted cell proliferation in MCF-7 cells. Five phenolic compounds (1-5) were separated and identified from the active fraction using bioassay-guided fractionation of crude A. tegmentosum extract and phytochemical analysis. The chemical structures of the compounds were characterized as vanillic acid (1), 4-hydroxy-benzoic acid (2), syringic acid (3), isoscopoletin (4), and (E)-ferulic acid (5) based on the analysis of their nuclear magnetic resonance spectra and liquid chromatography-mass spectrometry data. All five compounds were evaluated using an E-screen assay for their estrogen-like effects on MCF-7 cells. Among the tested compounds, only 4-hydroxy-benzoic acid (2) promoted the proliferation of MCF-7 cells, which was mitigated by the ER antagonist, ICI 182,780. The mechanism underlying the estrogen-like effect of 4-hydroxy-benzoic acid (2) was evaluated via western blotting analysis to determine the expression levels of extracellular signal-regulated kinase (ERK), phosphoinositide 3-kinase (PI3K), serine/threonine kinase (AKT), and ERα. Our results demonstrated that 4-hydroxy-benzoic acid (2) induced the increase in the protein expression levels of p-ERK, p-AKT, p-PI3K, and p-Erα, concentration dependently. Collectively, these experimental results suggest that 4-hydroxy-benzoic acid (2) is responsible for the estrogen-like effects of A. tegmentosum and may potentially aid in the control of estrogenic effects during menopause.

Stent expansion evaluated by optical coherence tomography and subsequent outcomes

Background

Regarding stent expansion indexes, previous optical coherence tomography (OCT) studies have shown minimal stent area (MSA) to be most predictive of adverse events.

Purpose

We sought to evaluate the impact of various stent expansion indexes by post-stent OCT on long-term clinical outcomes, and hence to find OCT-defined optimal stent expansion criteria.

Methods

Of the patients registered in the Yonsei OCT registry, a total of 1071 patients with 1123 native coronary artery lesions treated with new-generation drug-eluting stents under the OCT guidance and analyzable final post-stent OCT were included. Stent expansion indexes and different suboptimal stent expansion criteria were evaluated for their association with device-oriented clinical endpoints (DoCE) including cardiac death, target vessel-related myocardial infarction (TVMI) or stent thrombosis, and target lesion revascularization. Major safety events (MSE) included cardiac death, TVMI or stent thrombosis.

Results

The median follow-up period was 40.6 (interquartile range 22.0–50.0) months. As a continuous variable, MSA, adaptive volumetric stent expansion (stent volume/adaptive reference lumen volume) and overall volumetric stent expansion (stent volume/post-stent lumen volume) were significantly predictive of DoCE. As a categorical criteria, MSA <5.0 mm2 (hazard ratio [HR] 3.80; 95% confidence interval [CI] 1.53–9.45), MSA/distal reference lumen area <90% (HR 2.13; 95% CI 1.10–4.14), and overall volumetric stent expansion ≥96.6% (HR 2.38; 95% CI 1.09–5.22) were independently associated with DoCE after adjusting for confounders, and a total malapposition volume ≥7.0 mm3 (HR 3.38; 95% CI 1.05–10.93) was linked to MSE.

Conclusions

This OCT study highlights that sufficient stent expansion to achieve adequate absolute MSA and relative MSA by distal reference lumen area and alleviate significant malapposition is important to improve clinical outcome, but overall stent overexpansion may have deleterious effect.

Funding Acknowledgement

Type of funding sources: None.

Combinations of eight key mutations in the X/preC region and genomic activity of hepatitis B virus are associated with hepatocellular carcinoma

Accumulation of eight key mutations located in the X/preC regions of the hepatitis B virus (HBV) genome (G1613A, C1653T, T1753V, A1762T, G1764A, A1846T, G1896A and G1899A) is a risk marker for the development of hepatocellular carcinoma (HCC). In this study, we analysed the 8 key mutations in 442 serum samples collected from 310 non-HCC and 132 HCC patients to identify the combinations linked to HCC. After the patients were stratified according to the age groups and mutation combinations, clinical parameters were compared between the HCC and the non-HCC groups. Analyses were focused on patient ≥40 years of age infected by HBV genotype C with A1762T and G1764A mutations in the basal core promoter region (BCP double mutation). In patients with ≥6 mutations, the combination of [G1613A + C1653T + A1846T + G1896A] mutations was closely linked to HCC, whereas no specific single or double mutation combination was associated with HCC. In patients with ≤5 mutations, HBeAg and HBV DNA serum titres were lower in the HCC group than those in the non-HCC group. Unlike the number of mutations, no specific combination correlated with advanced clinical stage in HCC. Of the BCP double mutation-based HBV mutant types, combinations of ≥6 mutations that include G1613A + C1653T + A1846T + G1896A, and combinations of ≤5 mutations with reduced HBeAg production, may be more specific indicators of HCC risk than only the number of mutations or any specific combination(s).

Development of decay energy spectroscopy using low temperature detectors

We have developed a high-resolution detection technique for measuring the energy and activity of alpha decay events using low-temperature detectors. A small amount of source material containing alpha-emitting radionuclides was enclosed in a 4π metal absorber. The energy of the alpha particles as well as that of the recoiled nuclides, low-energy electrons, and low-energy x-rays and γ-rays was converted into thermal energy of the gold absorber. A metallic magnetic calorimeter serving as a fast and sensitive thermometer was thermally attached to the metal absorber. In the present report, experimental demonstrations of Q spectroscopy were made with a new meander-type magnetic calorimeter. The thermal connection between the temperature sensor and the absorber was established with annealed gold wires. Each alpha decay event in the absorber resulted in a temperature increase of the absorber and the temperature sensor. Using the spectrum measured for a drop of (226)Ra solution in a 4π gold absorber, all of the alpha emitters in the sample were identified with a demonstration of good detector linearity. The resolution of the (226)Ra spectrum showed a 3.3 keV FWHM at its Q value together with an expected gamma escape peak at the energy shifted by its γ-ray energy.

Reactive oxygen species-dependent necroptosis in Jurkat T cells induced by pathogenic free-living Naegleria fowleri

Naegleria fowleri, a free-living amoeba, is the causative pathogen of primary amoebic meningoencephalitis in humans and experimental mice. N. fowleri is capable of destroying tissues and host cells through lytic necrosis. However, the mechanism by which N. fowleri induces host cell death is unknown. Electron microscopy indicated that incubation of Jurkat T cells with N. fowleri trophozoites induced necrotic morphology of the Jurkat T cells. N. fowleri also induced cytoskeletal protein cleavage, extensive poly (ADP-ribose) polymerase hydrolysis and lactate dehydrogenase (LDH) release. Although no activation of caspase-3 was observed in Jurkat T cells co-incubated with amoebae, intracellular reactive oxygen species (ROS) were strongly generated by NADPH oxidase (NOX). Pretreating cells with necroptosis inhibitor necrostatin-1 or NOX inhibitor diphenyleneiodonium chloride (DPI) strongly inhibited amoeba-induced ROS generation and Jurkat cell death, whereas pan-caspase inhibitor z-VAD-fmk did not. N. fowleri-derived secretory products (NfSP) strongly induced intracellular ROS generation and cell death. Necroptotic effects of NfSP were effectively inhibited by pretreating NfSP with proteinase K. Moreover, NfSP-induced LDH release and intracellular ROS accumulation were inhibited by pretreating Jurkat T cells with DPI or necrostatin-1. These results suggest that N. fowleri induces ROS-dependent necroptosis in Jurkat T cells.

Combination drug therapy using edaravone and Daio-Orengedoku-to after transient focal ischemia in rats

In this study, we investigated the effect of Daio-Orengedoku-to (DOT) on ischemic brain damage in a rat model of focal ischemia-reperfusion and attempted to identify synergistic effects for the combination of edaravone and DOT against ischemic insult. Ischemia was induced by intraluminal occlusion of the right middle cerebral artery for 2 h and reperfusion followed for 22 h. To determine the neuroprotective effect of DOT, it was administered orally just before reperfusion and then 2 h after reperfusion. To examine the effects of combination therapy on survival, rats were divided into groups treated with edaravone, DOT, and edaravone and DOT. Microglial activation, neutrophil infiltration and brain-derived neurotrophic factor (BDNF) expression were examined in surviving animals. Infarct volume was significantly reduced by DOT (100, 200 and 400 mg/kg; P < 0.05), and edaravone plus DOT markedly improved the survival rate after transient ischemia (P = 0.0133). Microglial activation was reduced by edaravone and DOT and their combination (P < 0.05), and neutrophil infiltration was lowered in these groups (P < 0.05). BDNF-positive cells were increased in the combination edaravone and DOT group (P < 0.05). It appears that the neuroprotective mechanisms of combined therapy involve inhibition of microglial activation, reduction of invading neutrophils and enhancement of BDNF expression.

Self-optimization and auto-stabilization of receiver in DPSK transmission system

We propose a self-optimization and auto-stabilization method for a 1-bit DMZI in DPSK transmission. Using the characteristics of eye patterns, the optical frequency transmittance of a 1-bit DMZI is thermally controlled to maximize the power difference between the constructive and destructive output ports. Unlike other techniques, this control method can be realized without additional components, making it simple and cost effective. Experimental results show that error-free performance is maintained when the carrier optical frequency variation is approximately 10% of the data rate.

Cell cycle arrest and lytic induction of EBV-transformed B lymphoblastoid cells by a histone deacetylase inhibitor, Trichostatin A

Latent infection of the Epstein-Barr virus (EBV) is strongly associated with the pathogenesis of several human tumor types. The restricted expression of the latent EBV antigens is critical for EBV-associated tumors to escape from immune surveillance. EBV lytic replication can be triggered by various treatments and the induced lytic genes cause strong cytotoxic T lymphocyte (CTL) responses. Histone acetylation or deacetylation is associated with chromatin remodeling and regulates gene expression. Histone deacetylase (HDAC) inhibitors affect cell cycle progression as well as gene expression in a wide variety of transformed cells. We examined whether an HDAC inhibitor, TSA, can affect cell cycle progression and induce EBV lytic replication in EBV-transformed lymphoblastoid cell lines (LCLs). TSA caused cell cycle arrest at low concentrations and induced apoptosis at higher (>300 nM) concentrations in the LCLs and EBV negative BJAB cells. To clarify the underlying mechanism of TSA-induced cell cycle arrest, expression of cell cycle regulatory factors was examined by RNase protection assay and Western blot analysis. Following TSA treatment, a reduced expression of cyclin D2 and an induction of p21 may have played an essential role for G1 arrest in LCLs, while p21 induction might have arrested BJAB cells in G1 phase. A Cdk inhibitor, p57, was increased by 300 nM TSA in both LCLs and BJAB cells, indicating its role in apoptosis. Moreover, immunofluorescene assay and Western blotting showed that TSA induced EBV lytic replication in LCL cells. These results suggest that TSA may exert an enhanced anti-tumor effect for EBV-associated tumors not only by inducing a cell cycle arrest and apoptosis, but also by triggering an EBV lytic cycle.

Allergen-specific immunosuppression by ovalbumin fused with diphtheria toxin in mice sensitized with albumins of different origin

BACKGROUND

We previously reported that ovalbumin-diphtheria toxin (OVA-DT) fusion protein eliminates mast cells bearing OVA-specific IgE and protects OVA-sensitized mice from fatal anaphylaxis induced by OVA challenge.

OBJECTIVE

To prove the specificity of therapeutic effect of OVA-DT to allergy induced by OVA only and not by other allergens such as human serum albumin (HSA), and to examine the cytotoxic effect of OVA-DT on B cells bearing OVA-specific IgE.

METHODS

Mice were sensitized with two different antigens, OVA and HSA, and then treated with OVA-DT. The therapeutic effect of OVA-DT on the allergy response to each of allergen was evaluated by anaphylactic test. The effect of OVA-DT on the production of allergen-specific Ig isotypes of the sensitized mice and the cytotoxic effect of OVA-DT on B cells expressing OVA-specific IgE were examined.

RESULTS

OVA-DT suppressed only OVA-induced allergy but not HSA-induced allergy in mice sensitized with a mixture of OVA and HSA. The suppression was prolonged even to the mice boosted with the same allergen 14 days after last treatment of OVA-DT. In addition, when the sensitized mice were boosted with the same allergens 14 days after last treatment of OVA-DT, the mice showed to increase the production of OVA-specific IgG2a/IgG3 and decreased that of OVA-specific IgE. OVA-DT targeted B cells bearing OVA-specific IgE, and killed them by DT-mediated cytotoxicity.

CONCLUSION

The therapeutic effect of OVA-DT was specific to OVA-induced allergy and the suppression of OVA-induced allergy was continuously shown in the mice boosted with the same allergens. This is considered to be caused by the increase of OVA-specific IgG2a and IgG3, and because of the decrease of OVA-specific IgE by killing of B cells bearing OVA-specific IgE.

Mutational analysis of forkhead transcriptional factor 2 (FOXL2) in Korean patients with blepharophimosis-ptosis-epicanthus inversus syndrome

We screened for mutations in the forkhead transcription factor gene, FOXL2, in Korean patients with sporadic or familial blepharophimosis-ptosis-epicanthus inversus syndrome (BPES) by polymerase chain reaction-single-stranded conformation polymorphism (PCR-SSCP) and direct sequencing. Five of nine BPES families and three of seven sporadic cases were detected to have FOXL2 mutations. We identified four types of FOXL2 mutations, two of which are novel. A new 14 bp deletion (939-952del14) causing a frameshift from G235W and the extension of the predicted protein to 527 amino acids was detected in a BPES family patient. In addition, a novel 845C > A transversion, resulting in a nonsense mutation (S203X), was found in a sporadic case of BPES. The previously reported in-frame 30 bp duplication (909-938dup30) was the most common mutation and was found in eight patients of four BPES families and one sporadic case. A known 17 bp duplication (1080-1096dup17) was observed in a sporadic BPES case. We were unable to find a causal mutation in four BPES families and four sporadic cases. These results suggest that in a fraction of BPES patients, the genetic defect might be associated with a mutation in the non-coding region of the FOXL2 gene or in other genes.

Expression and secretion of the heterodimeric protein interleukin-12 in plant cell suspension culture

It has been suggested that plant cell culture is the most suitable system for producing small-to-medium quantities of specialized, expensive, and high-purity proteins. Here, we report that a heterodimeric protein, human interleukin-12 (hIL-12), was expressed and secreted into culture medium in a biologically active form. A transgenic plant expressing hIL-12 was constructed by sexual crossing of plants that expressed each subunit of the protein. From a piece of transgenic plant, callus was induced and cell suspension culture was established. The biological activity and amount of hIL-12 secreted into culture medium were analyzed using bioassays and ELISA. Analysis of cellular localization demonstrated that the protein was secreted into the culture medium together with its intrinsic signal peptide.

Hydraulic properties and leachate level analysis of Kimpo metropolitan landfill, Korea

Hydraulic properties of waste and cover soil from Kimpo Metropolitan Landfill were experimentally measured by laboratory tests. The degree of compaction was changed to identify the effect on hydraulic conductivity, field capacity, and permanent wilting point. Properties were utilized in developing a reliable numerical tool for leachate analysis. HELP, a simulation model for hydrologic evaluation of landfill performance, was adopted for that purpose. For calibration, results from simulation using the parameter values measured by laboratory tests were compared against the field data. The model was applied to predict the leachate level change according to the degree of compaction and cover soil thickness variation. It was found that the increase in the degree of compaction for intermediate cover soil and waste results in the decrease of field capacity and hydraulic conductivity, hence, the increase of leachate level. The effect of cover layer thickness on the leachate level was minor. Based on the findings from laboratory and numerical experiments, a guideline for reclamation practice was recommended.

A case of spontaneous pneumomediastinum and pneumopericardium in a young adult

Spontaneous medialstinal emphysema (pneumomediastinum) and pneumopericardium may be defined as the presence of free air or gas in the mediastinal structures and in the pericardial sac without an apparent precipitating cause. It most frequently occurs in young healthy adults without serious underlying pulmonary disease. Although pneumomediastinum and pneumopericardium is often asymptomatic, it may cause pain in the neck and chest, dysphonia and shortness of breath. Treatment is supportive unless the patient has a history of trauma from foreign body aspiration. The course of spontaneous pneumomediastinum and pneumopericardium is usually benign and self-limited. A case of spontaneous pneumomediastinum, pneumopericardium and subcutaneous emphysema in a 20-year-old male is reported in this paper.

DNA-mediated immunization of glycoprotein 350 of Epstein-Barr virus induces the effective humoral and cellular immune responses against the antigen

Epstein-Barr virus (EBV) is a human pathogen that is involved in numerous diseases and tumors. Since the EBV infection occurs in the early ages of life, and most of the population is subsequently exposed to EBV, the conventional method of vaccination to induce the prophylactic immunity cannot be considered effective in coping with the virus infection. In this study, we tested whether the injection of a plasmid vector that contained the gene for glycoprotein 350 (gp350), which had been identified as a ligand for virus' adsorption and a target for virus neutralizing antibodies, could induce effective immune responses against the antigen. As a result, the injection of the constructed plasmid vector into mice induced the production of gp350-specific antibodies. A major isotype of the gp350-specific antibodies was IgG1. The antibodies efficiently mediated the antibody-dependent cellular cytotoxicity against the cells expressing the gp350 antigen. In addition, the injection of the constructed plasmid vector stimulated the precursor T cell population that was specific to the gp350 antigen. In addition, gp350-specific cytotoxic T lymphocytes were efficiently stimulated by the injection of the constructed plasmid vector. These results suggested that the injection of the plasmid vector, containing the gp350 gene of Epstein-Barr virus, could be one of the most effective ways to induce both prophylactic and therapeutic vaccinations against the virus infection.

Cross-linking of MHC class II molecules with anti-MHC class II antibody or epitope peptide prevents resting B lymphocyte differentiation by inhibiting NF-kappaB-dependent gene expression

To understand the mechanism(s) involved in anti-MHC class II antibody-mediated inhibition of B lymphocyte differentiation, we investigated the influence of anti-MHC class II antibody treatment on the gene expression of IL-6 in resting B lymphocytes, which had been known to be one of the most important cytokines involved in B cell physiology. The level of the IL-6 mRNA expression in the LPS-stimulated resting B cells was remarkably reduced by treatment of the corresponding anti-MHC class II antibodies. The inhibition was exerted in haplotype-specific and dose-dependent manners. Similarly, MHC class II-restricted epitope peptides, when applied as a dimer form, revealed haplotype-specific and dose-dependent inhibitory effects on the IL-6 gene expression by the LPS-stimulated B cells. In addition, treatment of the anti-MHC class II antibody and MHC class II-restricted epitope peptide inhibited, in haplotype-specific and dose-dependent manners, the activation of NF-kappaB, which had been known to be one of the critical transcription factors involved in the IL-6 gene expression. Interestingly, however, exogenous addition of the recombinant IL-6 did not reverse this inhibitory effect by the anti-MHC class II antibody. These results suggest that conjugation of the MHC class II molecules by the anti-MHC class II antibody inhibited B cell differentiation, possibly through the interruption of signaling pathways leading to the IL-6 gene expression via NF-kappaB activation in B lymphocytes.

Immune induction and modulation in mice following immunization with DNA encoding F protein of respiratory syncytial virus

Respiratory syncytial virus (RSV) is one of the principal agents of bronchiolitis and pneumonia in young children. Thus, there is a strong need to make a safe and effective vaccine against the RSV infection. DNA immunization is very effective at inducing both cellular and humoral immune responses. In this study, we inserted the RSV-F gene into expression vectors, pcDNA3.1 and pQE. These constructs were transformed into C2C12 and E. coli M15 cells, respectively. The expression of the RSV-F protein was confirmed by SDS-PAGE, followed by Western blot analyses. The immunization of pcDNA3.1-RSV-F elicited both anti-RSV-F titer in mouse sera and CTL activities with mouse splenocytes. Especially, the co-administration of IL-4, or the GM-CSF gene with the RSV-F gene construct, enhanced the production of anti-RSV-F Ab. However, this enhancement disappeared by the simultaneous injection of the Th1 and Th2 type cytokine genes. The CTL activities were affected by the co-delivery of the IFN-gamma gene, but not by Th2-type cytokines.

Two-dimensional electrophoretic analysis of rice proteins by polyethylene glycol fractionation for protein arrays

Two-dimensional electrophoresis (2-DE) is known as the most effective as well as one of the simplest methods for separating proteins. However, a few hundred plant leaf proteins out of thousands visualized on a 2-DE gel can be identified by chemical analysis due to the presence of ribulose bisphosphate carboxylase/oxygenase (Rubisco) that limits protein loading. We describe the extraction and fractionation technique with polyethylene glycol (PEG) to analyze rice leaf proteins. Rice proteins were extracted with Mg/NP-40 extraction buffer. The Mg/Nonidet P-40 (NP-40) buffer extract was further fractionated with PEG into three fractions: 10% PEG and 10-20% PEG precipitants and the final supernatant fraction that was precipitated with acetone. Rubisco, the most abundant rice leaf protein, was enriched in the 20% PEG precipitant. This fractionation technique analyzed at least 2,600 well-separated protein spots and exhibited less than 1.2% of noticeable overlapping spots. An immunological approach was used to verify the efficiency whether PEG fractionation technique can detect or enrich signal transduction components such as Galpha, ADP ribosylation factor, small GTP binding protein and 14-3-3. The ADP ribosylation factor (ARF) and Galpha were only detected in the PEG supernatant fraction not in the total protein fraction. The small GTP binding protein (Rab 7) was identified in the 10% PEG fraction and only faintly in the total protein fraction. The 14-3-3 protein was detected in all fractions but was especially prevalent in the 20% PEG fraction.

Two-dimensional electrophoretic analysis of rice proteins by polyethylene glycol fractionation for protein arrays

Two-dimensional electrophoresis (2-DE) is known as the most effective as well as one of the simplest methods for separating proteins. However, a few hundred plant leaf proteins out of thousands visualized on a 2-DE gel can be identified by chemical analysis due to the presence of ribulose bisphosphate carboxylase/oxygenase (Rubisco) that limits protein loading. We describe the extraction and fractionation technique with polyethylene glycol (PEG) to analyze rice leaf proteins. Rice proteins were extracted with Mg/NP-40 extraction buffer. The Mg/Nonidet P-40 (NP-40) buffer extract was further fractionated with PEG into three fractions: 10% PEG and 10-20% PEG precipitants and the final supernatant fraction that was precipitated with acetone. Rubisco, the most abundant rice leaf protein, was enriched in the 20% PEG precipitant. This fractionation technique analyzed at least 2,600 well-separated protein spots and exhibited less than 1.2% of noticeable overlapping spots. An immunological approach was used to verify the efficiency whether PEG fractionation technique can detect or enrich signal transduction components such as Galpha, ADP ribosylation factor, small GTP binding protein and 14-3-3. The ADP ribosylation factor (ARF) and Galpha were only detected in the PEG supernatant fraction not in the total protein fraction. The small GTP binding protein (Rab 7) was identified in the 10% PEG fraction and only faintly in the total protein fraction. The 14-3-3 protein was detected in all fractions but was especially prevalent in the 20% PEG fraction.

Serologic and histopathologic study of Chlamydia pneumoniae infection in atherosclerosis: a possible pathogenetic mechanism of atherosclerosis induced by Chlamydia pneumoniae

Chronic infection and inflammation have recently been implicated as important etiologic agents for atherosclerosis in general and, in particular, ischemic heart disease. Several agents have been suggested as possible candidates for the chronic inflammation including cytomegalovirus, Helicobacter pylori and Chlamydia pneumoniae. We hypothesized that a vascular infection with C. pneumoniae may induce a chronic inflammatory reaction in the host vascular tissue and activated inflammatory cells may express inflammatory mediators such as cyclooxygenase-2 (COX-2) and matrix metalloproteinases (MMPs). At first, we evaluated the relationship between C. pneumoniae infection and atherosclerosis indirectly by serologic study, and then, to confirm our hypothesis, we performed an immunohistochemical study of atherosclerotic plaques. The seropositive rate of anti-Chlamydia pneumoniae IgG was higher in the disease group (Group I, 59.8%, n = 254) than in the negative control group (Group III, 47.4%, n = 97) (p = 0.041), but the anti-Chlamydia pneumoniae IgA was not different in seropositivity between the two groups (Group I, 64.6%; Group III, 57.7%). The simultaneous seropositive rates of both IgG and IgA were 56.7% in Group I and 43.3% in Group III (p = 0.033). In subgroups without the conventional risk factors of atherosclerosis, these findings were more prominent. Furthermore, we performed immunohistochemical staining on the atherosclerotic aortic tissues obtained from patients that were seropositive to C. pneumoniae (n = 5), by using antibodies to C. pneumoniae, COX-2, and MMP-9. The immunoreactivity for COX-2 and MMP-9 increased in the atherosclerotic plaques itself, predominantly in the surrounding area of immunoreactive C. pneumoniae. These findings support our hypothesis and C. pneumoniae may participate in a pathogenetic mechanism for atherogenesis or progression of atherosclerosis. The present study may open a promising perspective concerning future therapeutic trials of chronic inflammation related atherogenesis under pathophysiological conditions.

Fracture source location in thin plates using the wavelet transform of dispersive waves

A new signal processing approach was presented for acoustic emission source location using the dispersive waves in a thin plate. For wave propagation in dispersive media, the accuracy of source location can be improved by using the arrival times of a single frequency component in the output signals at an array of sensors. The wavelet transform (WT) was used to resolve this problem. By utilizing the time-frequency data of the WT, the frequency-dependent arrival time traveling with the group velocity was shown to be easily determined. Experiments were performed using a lead break as the simulated fracture source on the surface of an aluminum plate. Two plate modes corresponding to the S(0) and A(0) Lamb waves were identified, and their group velocities were accurately measured. The source location results based on the WT method agreed well with the true locations. The WT method was also compared with the cross correlation technique, and both methods provide similar results.

Effective immunotherapy of cancer by DNA vaccination

Direct injection of naked plasmid DNA either intramuscularly or intradermally induces strong, long-lived cell-mediated and humoral immune responses to the antigen encoded by the gene vaccine. In the present study, we used gene vaccination with naked plasmid DNA to induce prophylactic immune responses to tumor associated antigens. MAGE-1 (melanoma antigen 1) is an ideal candidate for cancer vaccines because it belongs to a family of genes that are expressed in a number of human tumors of various histological types but not in normal adult tissues except for the testis, and because both humoral and cell-mediated immune responses against MAGE-1 antigen were detected in tumor patients. Intradermal administration of plasmid DNA encoding MAGE-1 (pcMAGE1) induced anti-MAGE-1-specific antibody in BALB/c mice. In contrast, no detectable level of anti-MAGE-1 antibody was induced by intramuscular injection of pcMAGE1. Also, intradermal injection of pcMAGE1 was capable of generating CTLs reactive with MAGE-1-transfected murine tumor cells, M-MSV-MAGE1. Most of the mice (8 out of 10) immunized with pcMAGE1 rejected the challenge of M-MSV-MAGE1 tumor cells, compared with control animals most of which developed tumors. This suggests that intradermal DNA vaccination could provide a novel immunotherapy of cancer.

Administration of multiple cytokine genes with anti-tumor activity inhibits both tumor incidence and tumor growth

The finding of reporter gene expression in muscle cells after intramuscular injection of a reporter gene containing DNA has suggested that injection of a certain gene in its naked form could induce an expression of the injected gene. The result proposed the concept, namely DNA or genetic vaccine technology, that injection of an antigen gene could induce a specific immune response against the antigen. Although the concept was initially applied to vaccination technology, the result also means that administration of cytokine genes with anti-tumor activity could exert their functions when they are applied as a naked form of DNA. To test the possibility, plasmid vector containing granulocyte macrophage-colony stimulation factor (GM-CSF) and interleukin-12 (IL-12) genes, which are known as one of the most potent anti-tumor cytokines, were constructed and injected into mice together with syngeneic tumor cells. When the cytokine gene containing plasmid was injected on the same day of tumor cell injection, a tumor mass developed in 4 out of 5 mice tested. Even among the 4 mice, the tumor mass of a mouse disappeared 2 weeks after tumor development. In addition, tumor generation was significantly delayed in cytokine gene injected mice and the average tumor size was about 51.5% that of vector control injected mice. These results suggested that tumor treatment through the injection of multiple cytokine genes with potent anti-tumor activity significantly inhibits tumor development and growth, and that the method could be considered as one of the tools for efficient tumor treatment.

Cloning and analysis of the Epstein-Barr virus glycoprotein 350 genes

Membrane glycoprotein 350 (gp350) of the Epstein-Barr virus (EBV) is considered as a major target for vaccine development, since the gp350 has been identified as the virus' mediator for receptor interaction and as an inducer of specific in vitro virus-neutralizing antibodies. In an initial attempt to develop an effective DNA vaccine against an EBV infection, gp350 genes were isolated from SNU-20 and SNU-1103 which are the EBV-infected lymphoblastoid cell lines established in Korea. In addition, the nucleotide sequences of the gp350 genes were determined and compared with those of other EBV strains such as B95-8, P3HR-1/AG876 and M81. Sequence analysis showed that similar high degrees of homology between 2 EBV strains derived from African Burkitt's lymphoma, P3HR-1 and AG876, was shown between the gp350 genes isolated from 2 EBV-infected lymphoblastoid cell lines established in Korea. Furthermore, these 2 Korean and 2 African strains displayed nearly identical patterns of sequence variations from B95-8. In addition, the sequence of the isolated gp350 genes, which have been reported to be associated with the biology of EBV infection, is analyzed.

Up-regulation of the expression of major histocompatibility complex class I antigens by plasmid DNA transfection in non-hematopoietic cells

The effect of DNA on the surface expression of major histocompatibility (MHC) class I antigens was examined in non-hematopoietic tumor cell lines. Transfection with plasmid DNA via liposome or electroporation significantly increased the surface expression of MHC class I molecules in a transient manner. Northern blot analysis showed that levels of MHC class I mRNA were increased by DNA transfection, probably via transcriptional activation. In contrast, the expression of the MHC class II and beta-actin genes was not affected, suggesting that the up-regulation of MHC class I expression by plasmid DNA works in a gene-specific manner.

Alteration of signal-transducing molecules in tumor-infiltrating lymphocytes and peripheral blood T lymphocytes from human colorectal carcinoma patients

Tumor development or growth is accompanied by impaired immune responses, such as a poor proliferative response or down-regulated cytolytic T lymphocyte activity. Although recent reports have suggested that modification of the signal-transducing molecule is responsible for impaired immune responses in tumor-bearing hosts, the causes of defective immune function are not yet completely understood. Furthermore, the clinical significance of the findings is not yet clear. In this study, we investigated the alteration of several signal-transducing molecules in peripheral blood T lymphocytes (T-PBL) as well as in tumor-infiltrating lymphocytes (TIL) from human colorectal carcinoma patients and their relationship with the impaired host immune responses. A greater reduction in CD3zeta chain level was observed in TIL than in T-PBL from tumor-bearing hosts. CD3zeta chain reduction in T-PBL correlated with the clinicopathological stage of a tumor, especially with the status of lymph node metastasis. The levels of p56lck and p59fyn protein tyrosine kinase in T-PBL were also compared between tumor-bearing hosts and normal healthy volunteers. In T-PBL from tumor-bearing hosts, expression of protein tyrosine kinase p59fyn was significantly lower than that of p56lck. However, the level of CD3zeta chain expression did not correlate with T lymphocyte functions such as T lymphocyte proliferative response or allogeneic target cell lysis.

Establishment of a transgenic tobacco cell suspension culture system for producing murine granulocyte-macrophage colony stimulating factor

We tested if murine granulocyte-macrophage colony stimulating factor (mGM-CSF) is produced as a biologically active form through plant cell culture. The mGM-CSF gene was cloned into the plant expression vector, pBI121, and Ti-plasmid mediated transformation of tobacco leaves was conducted using Agrobacterium tumefaciens harboring the recombinant mGM-CSF (rmGM-CSF) gene. Cell suspension culture was established from the leaf-derived calli of transgenic tobacco plants. Northern blot analysis indicated the expression of the introduced mGM-CSF gene in both transgenic plant and cell suspension cultures. In addition, the biological activity of rmGM-CSF from plant cell culture was confirmed by measuring the proliferation of GM-CSF dependent FDC-P1 cells.

Isolation of ALU1-P gene encoding a protein with aluminum tolerance activity from Arthrobacter viscosus

We isolated a DNA fragment (ALU1-P) encoding a protein with an activity of aluminum tolerance from an Al tolerant soil microorganism, Arthrobacter viscosus. This microorganism was isolated from acidic tea field soils. The cloned DNA is composed of 1090 nucleotides, which has one open-reading frame without any stop codon. However, when the DNA fragment was transferred into Escherichia coli, a microorganism susceptible to Al toxicity, it endowed E. coli with Al tolerance. The deduced amino acid sequence of the DNA showed 65% identity with the protein of YbaX gene in Escherichia coli, and 51.1% identity with YB91 Haein hypothetical protein of HI1191 gene in Haemophilus influenzae. The ALU1-P gene in the expression vector produced a protein of 192 amino acids deriving a molecular weight of 21.3 kDa by using the stop codon in vector. The ALU1-P gene is a new one that has the characteristic of Al tolerance.

Coronary stenting (Cordis) without anticoagulation

We evaluated the effect of antithrombotic regimens on subacute thrombosis and short-term clinical courses after successful implantation of the Cordis coronary stent, which is a flexible, balloon expandable, radiopaque tantalum stent. Two hundred seventy-five consecutive patients with 290 lesions were treated with 356 Cordis stent implantations. According to poststent antithrombotic regimen, patients were divided into 3 groups; 165 patients with 175 lesions received aspirin 200 mg/day, ticlopidine 500 mg/day, and warfarin for 1 month (group 1), 66 patients with 69 lesions received aspirin and ticlopidine (group 2), and 44 patients with 46 lesions received aspirin alone (group 3) after successful Cordis stenting. The overall procedural success rates were 97.7% in group 1, 98.6% in group 2, and 100% in group 3. More than 65% of the patients were eligible for elective stenting. The overall rate of stent thrombosis was 1.8%: 1.2% in patients assigned to the treatment with aspirin, ticlopidine, and warfarin; 0% in patients with aspirin and ticlopidine; and 6.8% in patients assigned to the treatment with aspirin alone. In conclusion, the Cordis coronary stent is an effective endovascular stent in various clinical indications including unstable angina and acute myocardial infarction. Antiplatelet therapy using aspirin and ticlopidine after successful Cordis coronary stenting is a promising alternative to anticoagulation therapy to overcome the drawbacks of stenting. However, poststent antithrombotic therapy with aspirin alone is associated with a significant rate of stent thrombosis.

Colorectal cancer in familial adenomatous polyposis

PURPOSE

This study was performed to determine the relationship among surgical treatment, colorectal cancer, and outcome in patients with familial adenomatous polyposis (FAP).

METHODS

Records of 115 patients with FAP who underwent surgery at The Mount Sinai Medical Center between 1947 and 1994 were retrospectively reviewed. Patients without cancer were compared with those with colorectal cancer at initial surgery and with patients who developed rectal cancer following colectomy.

RESULTS

Thirty-one patients (27 percent) had colorectal cancer at the time of initial surgery (colon = 24; rectal = 7). Another 11 patients (26 percent) developed rectal cancer after colectomy with ileorectal anastomosis (IRA). Mean age of patients with colorectal cancer at initial surgery was significantly higher than those without cancer (P < 0.01). Patients who developed rectal cancer after IRA were significantly older than patients with colorectal cancer at initial surgery (P < 0.01). All patients with rectal cancer after IRA had advanced disease with either nodal or distant metastases at the time of diagnosis.

CONCLUSIONS

Colorectal cancer remains a major problem in the treatment of patients with FAP. Nearly one-fourth of these patients have colorectal cancer at initial operation, and one-fourth of patients with IRA develop rectal cancer after a mean follow-up of 13 years. Patients with rectal cancer following IRA are more likely to have advanced tumors than patients with colorectal cancer at initial operation. The high incidence and late stage of rectal cancer detected while under surveillance after IRA supports excision of the entire colorectal mucosa as the treatment of choice for most patients with FAP.

Role of a C-terminal residue of an immunodominant epitope in T cell activation and repertoire diversity

In the present study, the extent of heterogeneity in the high responder T cell response to the predominant epitope region of hen egg white lysozyme (HEL46-61) was examined. Through analyses of T cell proliferation and precursor frequency, the C3H T cell response is shown not to be limited to peptides containing the previously defined minimal epitope of residues 52-61, but rather is quite heterogeneous, encompassing much of the 46-61 sequence. Further characterization using a panel of T cell hybridoma clones revealed T cell recognition of diverse minimal epitopes within this region. Interestingly, these T hybridomas could be grouped into three distinct categories based on the ability to respond to peptides with or without the native arginine residue at position 61 (61-required, 61-inhibitory, dual responders). Using analogue peptides containing single amino acid substitutions at position 61, further heterogeneity within these hybridoma groups was identified, suggesting the presence of an extremely diverse T cell repertoire for the epitope region. The charge and/or size of the C-terminal residue appears to be a critical factor for certain clones; replacement of the native arginine residue with aspartic acid or glutamic acid enabled a nonstimulatory ligand to specifically antagonize a T cell hybridoma response. Collectively, these results strongly suggest that the C-terminal residue of the predominant epitope in high responder mice plays a critical role in T cell diversity and activation.

Role of a C-terminal residue of an immunodominant epitope in T cell activation and repertoire diversity

In the present study, the extent of heterogeneity in the high responder T cell response to the predominant epitope region of hen egg white lysozyme (HEL46-61) was examined. Through analyses of T cell proliferation and precursor frequency, the C3H T cell response is shown not to be limited to peptides containing the previously defined minimal epitope of residues 52-61, but rather is quite heterogeneous, encompassing much of the 46-61 sequence. Further characterization using a panel of T cell hybridoma clones revealed T cell recognition of diverse minimal epitopes within this region. Interestingly, these T hybridomas could be grouped into three distinct categories based on the ability to respond to peptides with or without the native arginine residue at position 61 (61-required, 61-inhibitory, dual responders). Using analogue peptides containing single amino acid substitutions at position 61, further heterogeneity within these hybridoma groups was identified, suggesting the presence of an extremely diverse T cell repertoire for the epitope region. The charge and/or size of the C-terminal residue appears to be a critical factor for certain clones; replacement of the native arginine residue with aspartic acid or glutamic acid enabled a nonstimulatory ligand to specifically antagonize a T cell hybridoma response. Collectively, these results strongly suggest that the C-terminal residue of the predominant epitope in high responder mice plays a critical role in T cell diversity and activation.

Initial clinical experience of intracoronary coil (Gianturco-Roubin) stents for management of acute dissection after balloon angioplasty

Dissections after percutaneous transluminal coronary angioplasty (PTCA) are risk factors for acute or subacute vessel closures. Intracoronary stenting was developed to avoid these complications by pressing the intimal and medial flaps against the vessel wall, thus reducing the risk of acute closure from thrombus formation. Thirty three coil (Gianturco-Roubin) stents were implanted into the coronary arteries of 32 patients with dissections after PTCA during the period of March 1993 to December 1993. The indications for stent implantation were acute closure in 6 (18.8%), threatened closure in 6 (18.8%) and suboptimal result in 20 (62.4%) patients. Stent insertion were successful in 30 (94%) patients. The diameter stenosis in an immediate angiographic findings after stenting was decreased from 87% to 18% by caliper estimation. Emergency coronary artery bypass graft surgery was required in 1 (3%) patient. A non-Q wave myocardial infarction occurred in 1 (3%) patient. Complications included hematoma of the arterial access site requiring blood transfusion in 4 (12.5%) patients and hemopericardium in 1 (3%) patient. Our initial clinical experience of flexible coil coronary stent imply that stenting is efficacious treatment for acute dissections that are causing acute or threatened closure following angioplasty. The long term follow-up result in all groups of patient who received coronary stents is needed for better evaluation of new devices and prognosis.

T cell epitope recognition involved in the low-responsiveness to a region of hen egg lysozyme (46-61) in C57BL/6 mice

The predominant T cell epitope of hen egg lysozyme (HEL) in high-responder C3H mice has been previously identified as the HEL 46-61 region. In contrast, this region is poorly recognized by T cells from low-responder C57BL/6 mice upon immunization with HEL. In previous studies, we have demonstrated that several C57BL/6 derived T cell hybridomas reactive to this epitope and other HEL epitopes preferentially recognize phosphorylcholine (PC)-conjugated HEL over unconjugated HEL. To understand the mechanisms involved in this difference of T cell recognition, we have further analysed the reactivity of T cells and T cell hybridomas from low-responder C57BL/6 mice. T cells from HEL-immunized mice were preferentially reactive to HEL 47-60. These results suggest a potential deficiency in generating an appropriate T cell epitope from the 46-61 region of native HEL in low-responder C57BL/6 mice. The minimal T cell epitope of this region was defined as HEL 51-60 using the PCH4.1 T hybridoma clone. This minimal epitope represents a single amino acid shift from the minimal epitope of HEL high-responder C3H mice (HEL 52-61). Various peptides representing this region were synthesized with single alanine substitutions at each position. The residues at positions 51, 52, 53 and 57 of HEL appear to be involved in Ia binding and the residues at 55 and 56 in contracting the TCR. T cell reactivity to HEL 51-61 peptides with various substitutions at position 61 strongly suggest that primarily the size of the C-terminal residue interferes with binding to the Ia molecules of low-responder mice. In addition, substitutions of the TCR contacting residues at positions 55 and 56 with similar residues (isoleucine-->leucine or leucine-->isoleucine) significantly increased the T cell reactivity, suggesting a low reactivity with the native residues. Therefore, the requirement of many residues in the T cell epitope for interaction with Ia, the necessity for additional Ag processing to facilitate Ia binding, and the low affinity of the TCR contacting residues may together render C57BL/6 mice unresponsive to the HE 46-61 region.

Acute myocardial infarction in the young adults

A review was done on 631 patients with acute myocardial infarction who underwent coronary angiography within 30 days after onset of myocardial infarction at Yonsei University Severance Hospital from January, 1985, to August, 1993. The incidence of acute myocardial infarction in patients under 40 years of age was 10.3% (65/631). Acute myocardial infarction below the fourth decades was the predominant disease of men. Risk factor analysis revealed a history of cigarette smoking and hypercholesterolemia were more frequently found in the young patients, but a history of hypertension and diabetes were more frequently found in the elderly patients. Angiographically, the incidence of one vessel disease and normal or minimal lesion coronary anatomy were more frequent in the young patients and incidence of multi-vessel disease were more frequent in the elderly patients. Of the 65 patients under 40 with acute myocardial infarction, the patients with multi-vessel disease tended to have a history of diabetes mellitus in comparison with those with normal coronary anatomy or one vessel disease.

Collateral circulation in total occlusion of the left anterior descending or right coronary artery

The functional significance of the collateral circulation was evaluated in 125 patients with total coronary occlusion. Patients were classified into two groups. Group 1:patients with angina pectoris (AP), Group 2:patients with a first transmural myocardial infarction (MI) within 3 months of the symptom onset. Clinical variables, resting and exercise electrocardiogram (EKG) were analyzed with angiographic findings. Collateral fillings were graded from 0 to 3: 0 = none; 1 = filling of side branches only; 2 = partial filling of the epicardial segment; 3 = complete filling of epicardial segment. The wall motion of each segment was scored from 1 to 5: 1 = normal; 2 = mild to moderate hypokinesia; 3 = severe hypokinesia; 4 = akinesia; 5 = dyskinesia. The scores of the 5 segments were added to yield a total LV score. There was a higher prevalence of good collaterals and multi-vessel disease in patients with AP than in those with MI (83% vs 53%, 54% vs 30%, respectively, p < 0.005). The left ventricular ejection fraction (LVEF), left ventricular end-diastolic pressure (LVEDP) and segmental wall motion score were significantly better in patients with AP than in those with MI (68.9 +/- 13.4%, vs 50.5 +/- 12.6%, 15.0 +/- 7.3 mmHg vs 20.3 +/- 8.8 mmHg, 6.5 +/- 2.2 vs 9.6 +/- 2.3, respectively, p < 0.05). In spite of total coronary occlusion, 61% of AP patients had normal resting EKG but (96% of AP patients who underwent treadmill test proved positive. The proportions of well-developed collaterals in 3 groups divided according to the interval between onset of MI and angiography (within 1 day, 2 to 14 days, 15 days to 3 months) were 13%, 54% and 60%. There were no significant differences in LVEF, segmental wall motion score and LVEDP in MI patients with poorly-developed collaterals and well-developed collaterals (49.1 +/- 15.7% vs 46.4 +/- 10.1%, 11.1 +/- 2.2 vs 10.9 +/- 1.4 and 24.3 +/- 9.7 mmHg vs 20.3 +/- 7.0 mmHg, p = NS). The degree of collateral development was higher in MI with right coronary artery occlusion compared with that of left anterior descending artery occlusion (1.1 +/- 1.0 vs 2.0 +/- 1.0, p < 0.05). In conclusion, collateral circulation can prevent myocardial ischemia and preserve myocardial function in a significant number of patients with AP but do not provide protection against exercise-induced myocardial ischemia in the majority of patients with AP.(ABSTRACT TRUNCATED AT 400 WORDS)

Percutaneous mitral balloon valvuloplasty in patients with restenosis after surgical commissurotomy: a comparative study

We performed percutaneous mitral balloon valvuloplasty (PMV) in 367 patients to compare the effectiveness of PMV between patients with mitral restenosis after surgical commissurotomy (group 1) and patients with unoperated mitral stenosis (group 2). Twenty-two had undergone closed or open mitral commissurotomy 11.2 years before. There were no significant differences in clinical profiles between the two groups. The mitral valve area was increased from 1.0 +/- 0.8 to 1.8 +/- 0.6 cm2 in group 1 and 0.9 +/- 0.3 to 2.0 +/- 0.7 cm2 in group 2 (p > 0.05). The mitral gradient was decreased from 14 +/- 5.9 to 6 +/- 2.6 mmHg in group 1 and 18 +/- 7.0 to 7 +/- 5.3 mmHg in group 2 (p > 0.05). The increment of mitral regurgitation and significant left to right shunt after PMV were not significantly different (10% versus 14.7%, 5% versus 10.4% respectively). Optimal results were attained in 75% of the patients in group 1 and in 84.3% of the patients in group 2 (p > 0.05). These results suggest PMV in mitral restenosis after surgical commissurotomy may be safe in selected patients and may be equally effective as in unoperated mitral stenosis.

Comparison of outcome among double, bifoil and Inoue balloon techniques for percutaneous mitral valvuloplasty in mitral stenosis

The efficacy and complications of three different methods of percutaneous mitral valvuloplasty (PMV) were evaluated in 245 patients with mitral stenosis (MS). Eight six patients (35%) had severe MS defined in the mitral valve area (MVA) less than 1.0 cm2 (0.8 +/- 0.2) and Echoscore greater than or equal to 8(8.9 +/- 1.1). The results including post MCA greater than or equal to 1.5cm2 and complications, i.e, increment of mitral regurgitation (MR) greater than or equal to +1 and atrial septal defect (ASD) with Qp/Qs greater than or equal to 1.5 were compared in overall and in severe MS groups. There was no statistically significant difference in size of MVA before and after PMV between overall patients group and severe mitral stenosis group (0.8 +/- 0.1 vs 1.7 +/- 0.4cm2 in the double technique, 0.8 +/- 0.2 vs 1.5 +/- 0.3cm2 in the Bifoil technique and 0.7 +/- 0.2 vs 1.8 +/- 0.3cm2 in the Inoue technique. p: NS). However, a significantly larger number of patients in the severe MS group had better MVA with the double than the Bifoil technique [MVA greater than or equal to 1.5cm2; 42 (72%) vs 6 (46%), p less than 0.005] whereas higher complications were observed with the Bifoil than the Inoue technique (MR greater than or equal to +1; 9 (69%) vs 4 (27%), ASD (Qp/Qs greater than or equal to 1.5' 6 (46%) vs 2 (13%) p less than 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)

Constraints in antigen processing result in unresponsiveness to a T cell epitope of hen egg lysozyme in C57BL/6 mice

T cell hybridoma clones were derived after fusion of BW-5147 parent cells with lymphocytes from C57BL/6 mice injected with phosphorylcholine (PC)-hen egg lysozyme (HEL) conjugates. Several T cell hybridomas were preferentially reactive with PC-HEL over unconjugated HEL, and a particular clone (PC-H4.1) was further analyzed. This T cell hybridoma clone could respond to its maximal level toward unconjugated HEL only when the dose of HEL was increased to 5-10-fold of the PC-HEL concentration. Interestingly, this clone was not stimulated by unfolded HEL (by S-carboxymethylation) to the level of PC-HEL. A synthetic peptide representing the amino acid position 47-61 of HEL, which is known to be non-immunogenic upon HEL injection in C57BL/6 mice, was able to stimulate the hybridoma only to a level comparable to that induced by unconjugated HEL. The T cell response to this synthetic peptide required an additional antigen-processing step, based on its inability to stimulate T cells after treatment of antigen-presenting cells with leupeptin, chloroquine or paraformaldehyde. Deletion of a single C-terminal amino acid residue of HEL 47-61 (arginine) significantly enhanced (10-100-fold of HEL 47-61) the T cell reactivity and abrogated the necessity of further antigen processing. These results suggest that the lack of a T cell response to a certain epitope may not be due to the lack of a T cell repertoire reactive to the epitope. In some cases, the unresponsiveness may be due to the difficulty in generating the particular epitopes. Taken together, modification of the lysozyme molecule with PC conjugation may facilitate further antigen processing of HEL to generate an optimal epitope for the nonresponder mice.

Analysis of T cell reactivities to phosphorylcholine-conjugated hen egg lysozyme in C57BL/6 mice: hapten-conjugate specificity reflects an altered expression of a major carrier epitope

We have selected several different T cell hybridoma clones reactive to hen egg lysozyme (HEL) conjugated to phosphorylcholine (PC) after fusion of PC-HEL-primed C57BL/6 lymphocytes with BW5147 parent cells. These hybridoma clones preferentially recognize PC-HEL over unconjugated HEL, but not other carrier molecules conjugated with the same hapten. All the PC-HEL-reactive clones are similarly responsive to not only p-azobenzenearsonate (ABA)-conjugated HEL (ABA-HEL) but also to a variety of other diazotized hapten-HEL conjugates. However, these clones are not stimulated by fluoresceinated or dinitrophenylated HEL beyond the level of HEL carrier alone. Therefore, the type of hapten linkage (diazonium) to the carrier molecule appears to affect T cell recognition. The hybridoma clones apparently recognize the carrier molecule alone, although the level of stimulation is relatively low compared to that induced by either PC-HEL or ABA-HEL. Interestingly, HEL unfolded by S-carboxymethylation is capable of stimulating the hybridomas to a level comparable to that obtained with PC-HEL. T cell recognition of the unfolded HEL is independent of antigen processing, which is different from that of PC-HEL. The peptide sequence corresponding to the amino acids 81-93 of HEL appears to contain the epitope region for the hybridoma clones based on testing stimulation activity with synthetic peptides. Previously, the peptides including this region (81-96) have been reported as the determinant recognized by T cells derived from C57BL/6 mice after immunization with an HEL peptide (HEL 13-105) but not with native HEL. These results suggest that a hapten conjugation via diazonium linkage modifies antigen presentation and consequently the presentation of the major T cell epitopes similar to that of the HEL fragment.

Clinical and coronary angiographic findings of 400 Korean adults with coronary artery disease

The clinical and angiographic findings of Korean adults with coronary artery disease (obstructions exceeding 50% of the internal diameter of the lumen of one or more major coronary arteries) were studied in 400 of 670 patients on whom selective cinecoronary arteriograms were performed at the Department of Internal Medicine, Yonsei University, College of Medicine between January 1981 and August 1986. Among the 400 cases with significant coronary atherosclerosis, a clinical diagnosis of unstable angina (including new-onset angina in which angina developed within 3 months) was made in 45.8%, stable angina in 16.0%, variant angina, 3.7%, acute myocardial infarction, 17.3%, and old myocardial infarction, 17.3%. Single vessel disease was more prevalent in the group with unstable angina (53%) than with stable angina (47%). The incidence of multi-vessel involvement was low in patients with acute myocardial infarction (46%), in contrast to a much higher incidence in the group with old myocardial infarction with angina (76%). An average of 2.2 lesions resulting in at least 50% luminal narrowing of the major arteries was found per patient. The anterior descending coronary artery was involved more frequently than other vessels.