Stenting with intravenous abciximab infusion for the treatment of left main coronary artery thrombosis during coronary angioplasty

A 67-year-old female patient complained of exertional precordial chest pain with radiation to the left shoulder occurring over a two-month period. An acute non-Q wave anterior myocardial infarction was diagnosed. On the third day of admission, coronary angiography revealed two-vessel disease with 73% luminal narrowing of the proximal left anterior descending coronary artery and 50% luminal narrowing of the mid-right coronary artery. The initial attempt to implant a NIR stent (Boston Scientific/Scimed, Inc., Maple Grove, Minnesota) was unsuccessful. We report on the successful rescue implantation of two MAC (Maximum Arterial re-Creation) stents (Advanced Medical Technologies, Germany), in conjunction with the infusion of abciximab for the treatment of an abrupt closure due to thrombus of the left main coronary artery.

Guidewire-induced coronary artery perforation treated with transcatheter injection of polyvinyl alcohol form

We describe a first case of successful transcatheter management of guidewire-induced distal coronary artery perforation and impending cardiac tamponade, which developed during percutaneous coronary angioplasty, with transcatheter injection of polyvinyl alcohol form. This method may be an effective alternative in the management of distal coronary artery perforation requiring surgical repair.

Probing the binding domain of the Saccharomyces cerevisiae alpha-mating factor receptor with rluorescent ligands

Three analogues of the alpha-mating factor pheromone of Saccharomyces cerevisiae containing the 7-nitrobenz-2-oxa-1,3-diazol-4-yl (NBD) group were synthesized that had high binding affinity to the receptor and retained biological activity. The fluorescence emission maximum of the NBD group in [K7(NBD),Nle(12)]-alpha-factor was blue shifted by 35 nm compared to buffer when the pheromone bound to its receptor. Fluorescence quenching experiments revealed that the NBD group in [K7(NBD),Nle(12)]-alpha-factor bound to the receptor was shielded from collision with iodide anion when in aqueous buffer. In contrast, the emission maximum of NBD in [K7(ahNBD),Nle(12)]-alpha-factor or [Orn7(NBD),Nle(12)]-alpha-factor was not significantly shifted and iodide anion efficiently quenched the fluorescence of these derivatives when they were bound to receptor. The fluorescence investigation suggests that when the alpha-factor is bound to its receptor, K7 resides in an environment that has both hydrophobic and hydrophilic groups within a few angstroms of each other.

Immunohistochemical study on the distribution of the voltage-gated potassium channels in the gerbil hippocampus

The differential expression of specialized voltage-gated potassium (Kv) channel subtypes probably reflects the wide range of functions in the nervous system. In the present study, we investigated the distribution of six Kv1 channel subtypes in the gerbil hippocampus by immunohistochemistry. Immunoreactivities for Kv1.1, Kv1.2, Kv1.4 and Kv1.6 were observed in the pyramidal cells of the CA1-CA3 areas. In addition, many medium- to large-sized interneurons located within stratum pyramidals, stratum oriens, and stratum radiatum of CA1-CA3 were strongly immunoreactive for Kv1.4. Although there was some overlap, our results were quite different from the previous studies described in the rat and mouse hippocampus, in that we observed intense staining mainly in the cell bodies of the pyramidal cells and granule cells. As a whole, the present study has clearly shown Kv1 channel distributions in the gerbil hippocampus, which were variant between species and therefore more or less functionally significant. This study may provide useful data for the future investigations on the pathological conditions such as ischemia and epilepsy.

Cost-effectiveness of radiofrequency ablation for supraventricular tachycardia

BACKGROUND

Radiofrequency ablation is an established but expensive treatment option for many forms of supraventricular tachycardia. Most cases of supraventricular tachycardia are not life-threatening; the goal of therapy is therefore to improve the patient's quality of life.

OBJECTIVE

To compare the cost-effectiveness of radiofrequency ablation with that of medical management of supraventricular tachycardia.

DESIGN

Markov model.

DATA SOURCES

Costs were estimated from a major academic hospital and the literature, and treatment efficacy was estimated from reports from clinical studies at major medical centers. Probabilities of clinical outcomes were estimated from the literature. To account for the effect of radiofrequency ablation on quality of life, assessments by patients who had undergone the procedure were used.

TARGET POPULATION

Cohort of symptomatic patients who experienced 4.6 unscheduled visits per year to an emergency department or a physician's office while receiving long-term drug therapy for supraventricular tachycardia.

TIME HORIZON

Patient lifetime.

PERSPECTIVE

Societal.

INTERVENTIONS

Initial radiofrequency ablation, long-term antiarrhythmic drug therapy, and treatment of acute episodes of arrhythmia with antiarrhythmic drugs.

OUTCOME MEASURES

Costs, quality-adjusted life-years, life-years, and marginal cost-effectiveness ratios.

RESULTS OF BASE-CASE ANALYSIS

Among patients who have monthly episodes of supraventricular tachycardia, radiofrequency ablation was the most effective and least expensive therapy and therefore dominated the drug therapy options. Radiofrequency ablation improved quality-adjusted life expectancy by 3.10 quality-adjusted life-years and reduced lifetime medical expenditures by $27 900 compared with long-term drug therapy. Long-term drug therapy was more effective and had lower costs than episodic drug therapy.

RESULTS OF SENSITIVITY ANALYSIS

The findings were highly robust over substantial variations in assumptions about the efficacy and complication rate of radiofrequency ablation, including analyses in which the complication rate was tripled and efficacy was decreased substantially.

CONCLUSIONS

Radiofrequency ablation substantially improves quality of life and reduces costs when it is used to treat highly symptomatic patients. Although the benefit of radiofrequency ablation has not been studied in less symptomatic patients, a small improvement in quality of life is sufficient to give preference to radiofrequency ablation over drug therapy.

Associations of blood lead, dimercaptosuccinic acid-chelatable lead, and tibia lead with polymorphisms in the vitamin D receptor and [delta]-aminolevulinic acid dehydratase genes

A cross-sectional study was performed to evaluate the influence of polymorphisms in the [delta]-aminolevulinic acid dehydratase (ALAD) and vitamin D receptor (VDR) genes on blood lead, tibia lead, and dimercaptosuccinic acid (DMSA)-chelatable lead levels in 798 lead workers and 135 controls without occupational lead exposure in the Republic of Korea. Tibia lead was assessed with a 30-min measurement by (109)Cd-induced K-shell X-ray fluorescence, and DMSA-chelatable lead was estimated as 4-hr urinary lead excretion after oral administration of 10 mg/kg DMSA. The primary goals of the analysis were to examine blood lead, tibia lead, and DMSA-chelatable lead levels by ALAD and VDR genotypes, controlling for covariates; and to evaluate whether ALAD and VDR genotype modified relations among the different lead biomarkers. There was a wide range of blood lead (4-86 microg/dL), tibia lead (-7-338 microg Pb/g bone mineral), and DMSA-chelatable lead (4.8-2,103 microg) levels among lead workers. Among lead workers, 9.9% (n = 79) were heterozygous for the ALAD(2) allele and there were no homozygotes. For VDR, 10.7% (n = 85) had the Bb genotype, and 0.5% (n = 4) had the BB genotype. Although the ALAD and VDR genes are located on different chromosomes, lead workers homozygous for the ALAD(1) allele were much less likely to have the VDR bb genotype (crude odds ratio = 0.29, 95% exact confidence interval = 0.06-0.91). In adjusted analyses, subjects with the ALAD(2) allele had higher blood lead levels (on average, 2.9 microg/dL, p = 0.07) but no difference in tibia lead levels compared with subjects without the allele. In adjusted analyses, lead workers with the VDR B allele had significantly (p < 0.05) higher blood lead levels (on average, 4.2 microg/dL), chelatable lead levels (on average, 37.3 microg), and tibia lead levels (on average, 6.4 microg/g) than did workers with the VDR bb genotype. The current data confirm past observations that the ALAD gene modifies the toxicokinetics of lead and also provides new evidence that the VDR gene does so as well.

Measurement of radiation absorbed dose in endovascular Ho-166 brachytherapy using a balloon angio-catheter

The purpose of this study was to estimate the absorbed dose distribution of Ho-166 endovascular beta irradiation using an angio-catheter. The liquid form of Ho-166 was produced at the Korea Atomic Energy Research Institute (KAERI) by an (n,gamma) reaction. Ho-166 has a half-life of 26.8 h and emits a high-energy beta particle with a maximum energy of 1.85 MeV. GafChromic film was used for the estimation of the absorbed dose of beta particles. A Co-60 teletherapy source and a 6 MV photon beam from a linear accelerator were used to generate dose-optical density calibration curves. The exposed films were read using a videodensitometer. With a modified micrometer, the film was positioned accurately on the surface of the balloon in water. The balloon was filled with Ho-166 solution to a pressure of 4 atm. Several film exposures were made with varying irradiation times and activities. The radiation absorbed dose rates were 1.02, 0.51 and 0.35 Gy x min(-1) x GBq(-1) x ml(-1) at the balloon surface, 0.5 and 1 mm from the balloon surface, respectively. The absorbed dose distribution revealed that Ho-166 is a good source for endovascular irradiation as the beta range is very short, avoiding unnecessary irradiation of normal tissue. A clinically applicable irradiation and duration of exposure were achievable utilizing our system.

Characteristics of Vibrio parahaemolyticus O3:K6 from Asia

A variety of serovars of the food-borne pathogen Vibrio parahaemolyticus normally cause infection. Since 1996, the O3:K6 strains of this pathogen have caused pandemics in many Asian countries, including Taiwan. For a better understanding of these pandemic strains, the recently isolated clinical O3:K6 strains from India, Japan, Korea, and Taiwan were examined in terms of pulsed-field gel electrophoresis (PFGE) typing and other biological characteristics. After PFGE and cluster analysis, all the O3:K6 strains were grouped into two unrelated groups. The recently isolated O3:K6 strains were all in one group, consisting of eight closely related patterns, with I1(81%) and I5(13%) being the most frequent patterns. Pattern I1 was the major one for strains from Japan, Korea, and Taiwan. All recently isolated O3:K6 strains carried the thermostable direct hemolysin (tdh) gene. No significant difference was observed between recently isolated O3:K6 strains and either non-O3:K6 reference strains or old O3:K6 strains isolated before 1996 with respect to antibiotic susceptibility, the level of thermostable direct hemolysin, and the susceptibility to environmental stresses. Results in this study confirmed that the recently isolated O3:K6 strains of V. parahaemolyticus are genetically close to each other, while the other biological traits examined were usually strain dependent, and no unique trait was found in the recently isolated O3:K6 strains.

Coordinate expression of novel genes during osteoblast differentiation

To achieve new insights into the coordinate regulation of gene expression during osteoblast differentiation we utilized an approach involving global analysis of gene expression to obtain the identities of messenger RNAs (mRNAs) expressed using an established in vitro model of bone development. MC3T3-E1 osteoblast-like cells were induced to differentiate by the addition of beta-glycerophosphate (beta-GP) and ascorbic acid. RNA samples derived from induced and uninduced control MC3T3-E1 cells were used to prepare complementary DNA (cDNA) for serial analysis of gene expression (SAGE). A preliminary SAGE database was produced and used to prepare a hybridization array to further facilitate the characterization of changes in the expression levels of 92 of the SAGE-mRNA assignments after induction of osteoblast differentiation, specifically after 6 days and 14 days of ascorbate treatment. SAGE-array hybridization analysis revealed coordinate induction of a number of mRNAs including Rab24, calponin, and calcyclin. Levels of MSY-1, SH3P2, fibronectin, alpha-collagen, procollagen, and LAMPI mRNAs, present at day 6 postinduction, were markedly reduced by day 14 postinduction. A number of unanticipated and potentially important developmental genes were identified including the transforming growth factor beta (TGF-beta) superfamily member Lefty-1. Lefty-1 transcript and translation product were found to be induced during the course of MC3T3-E1 cell differentiation. We present evidence, using transient transfection and antibody neutralization approaches, that Lefty-1 modulates the induction of alkaline phosphatase (ALP) after treatment of MC3T3-E1 cells with ascorbate and beta-GP. These data should provide useful new information for future analysis of transcriptional events in osteoblast differentiation and mineralization.

Position 13 analogs of the tridecapeptide mating pheromone from Saccharomyces cerevisiae: design of an iodinatable ligand for receptor binding

Analogs of the alpha-factor tridecapeptide mating pheromone (WHWLQLKPGQPMY) from Saccharomyces cerevisiae in which Tyr13 was replaced with Phe, p-F-Phe, m-F-Phe, p-NO2-Phe, p-NH2-Phe or Ser were synthesized and purified to >99% homogeneity. These analogs were bioassayed using a growth arrest assay and a gene induction assay and evaluated for their ability to compete with binding of tritiated alpha-factor to its receptor Ste2p. The results showed that the phenolic OH of Tyr13 is not required for either biological activity or receptor recognition. Analogs containing fluorine, amino, nitro or a hydrogen in place of OH had 80-120% of the biological activity of the parent pheromone in the gene induction assay and had receptor affinities from nearly equal to 6-fold lower than that of alpha-factor. In contrast, substitution of Ser or Ala at position 13 resulted in a >100-fold decrease in receptor affinity suggesting that the aromatic ring is involved in binding to the receptor. The lack of a strict requirement for Tyr13 allowed the design of several multiple replacement analogs in which Phe or p-F-Phe were substituted at position 13 and Tyr was placed in other positions of the peptide. These analogs could then be iodinated and used in the development of a highly sensitive receptor-binding assay. One potential receptor ligand [Tyr(125I)1,Nle12, Phe13] alpha-factor exhibited saturable binding with a KD of 81 nM and was competed by alpha-factor for binding in a whole-cell assay. Thus a new family of radioactive ligands for the alpha-factor receptor has been revealed. These ligands should be extremely useful in defining active site residues during mutagenesis and cross-linking studies.

A comparison of different lead biomarkers in their associations with lead-related symptoms

OBJECTIVES

To evaluate whether dimercaptosuccinic acid (DMSA) -chelatable lead, an estimate of current bioavailable lead stores, is a better predictor of lead-related symptoms than are other commonly used lead biomarkers.

METHODS

A total of 95 male lead workers from three lead industries (one secondary lead smelting facility, one polyvinyl chloridestabilizer manufacturing plant, and one lead-acid storage battery factory), and 13 workers without occupational lead exposure recruited from an occupational health institute, were studied. Blood lead, blood zinc protoporphyrin (ZPP), 4 h DMSA-chelatable lead (after oral administration of 10 mg/kg DMSA), urine lead, and urinary delta-aminolevulinic acid levels were evaluated as predictors of 15 lead-related symptoms, assessed by self-administered questionnaire, with linear and logistic regression controlling for covariates. Total symptoms and symptoms in three categories (gastrointestinal, neuromuscular, and general) were evaluated.

RESULTS

The mean (SD) 4 h DMSA-chelatable lead level was 288.7 (167.7) microg, with a range from 32.4 to 789 microg in the 95 lead workers. The mean (SD) in the non-exposed subjects was 23.7 (11.5) microg with a range from 10.5 to 43.5 microg. Blood lead, blood ZPP, and spot urine lead levels ranged from 21.4 to 78.4 microg/dl, 40 to 331 microg/l, and 7.5 to 153.0 micro/l, respectively, in the lead workers, and from 4.0 to 7.2 micro/dl, 27 to 52 microg/l, and 2.9 to 15.5 microg/l in the non-exposed controls, respectively. The overall mean symptom score (SD), derived as the sum of 0 or 1 point for absence or presence of 15 symptoms, of the lead workers was 3.7 (2.0), compared to 1.2 (1.5) for the non-exposed workers. DMSA-chelatable lead was the best predictor of symptom scores in both crude and adjusted analyses, compared with the other biomarkers. Lead workers with DMSA-chelatable lead values greater than the median (260.5 microg) were 6.2 times more likely to have frequent tingling or numbness of the arms or legs and 3.3 times more likely to have muscle pain than subjects with lower chelatable lead values. Three symptoms (tingling or numbness of arm or leg, muscle pain, and feeling irritation at the slightest disturbance) evidenced a dose-dependent relationship with DMSA-chelatable lead levels.

CONCLUSIONS

DMSA-chelatable lead was found to be the best predictor of lead-related symptoms, particularly of both total symptom scores and neuromuscular symptoms, than were the other other lead biomarkers.

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.

Coexpression of cyclooxygenase-2 and matrix metalloproteinases in human aortic atherosclerotic lesions

Inflammation appears to have a major role in the development of atherosclerosis. Cyclooxygenase-2 (COX-2) is involved in the inflammatory response via the generation of prostanoids that, in turn, are involved in the production of matrix metalloproteinases (MMPs). This study aimed to investigate atherosclerosis in human aortas for in situ tissue distribution of COX-2, MMPs including MMP-9 and membrane type 1 MMP (MT1-MMP), and tissue inhibitor of metalloproteinase-2 (TIMP-2). Immunohistochemical studies were performed on atherosclerotic lesions of aortas from patients with aortic aneurysms (n = 4) and dissections (n = 3) by using antibodies to COX-2, MMP-9, MT1-MMP, and TIMP-2. Control tissues were obtained from traumatically dissected aortas (n = 2). All specimens from diseased aortas had atherosclerotic lesions ranging from fatty streak to atheromatous plaques. In control, there was no expression of COX-2, MMP-9, and MT1-MMP in all aortic layers. Immunoreactivity for COX-2 was predominantly noted in macrophages and smooth muscle cells (SMCs) of the intima including atherosclerotic plaque itself and the medial layer of the plaque base, as well as in SMCs and endothelial lining of the vasa vasorum in the adventitia. Immunoreactivity for MMP-9 and MT1-MMP was found in the same distribution as that of COX-2. Additionally, the expression of TIMP-2 increased in relation to MMP-9 expression. This study demonstrates that COX-2 is coexpressed with MMP-9 and MT1-MMP, not only by macrophages and SMCs in atherosclerotic lesions, but also in endothelial lining of the vasa vasorum of human aortas. Thus, vascular inflammatory reactions may influence extracellular matrix remodeling by coactivation of MMPs in the development of atherosclerosis and, in turn, the progression of disease.

The role of biological monitoring in the health management of lead-exposed workers

In 1967, the problem of occupational lead exposure came to public attention in Korea. Since then, regular progress has been made in lowering workplace lead exposures, instituting new workplace controls, and implementing health examinations of exposed workers. Serious lead poisoning episodes led to the introduction of biological monitoring programs on a voluntary basis in high lead exposure facilities in Korea. Occupational health services for lead workers in Korea during the last 10 years could be categorized into three phases. During the first phase (1988-1993), effort was directed at increasing awareness among workers concerning the hazards of lead exposure, biological monitoring was commenced with zinc protoporphyrin (ZPP), and a respiratory protection program was introduced. During the second phase (1994-1996), a computerized health management system of lead workers was developed, blood lead measurement was added for biological monitoring, and engineering controls were introduced in the workplace to lower air lead levels to comply with air lead regulations. Finally, during the third phase (1997-present), bone lead measurement by X-ray fluorescence was introduced to evaluate total body lead burden. During the period 1988-1998, air lead levels have remained generally steady and above the permissible exposure level (PEL), but ZPP and blood lead levels have shown a steady decline. It was discovered that in a developing country like Korea, which cannot introduce engineering controls quickly to protect lead workers, biological monitoring was very useful in identifying and lowering excess lead absorption. In the future, as average exposure duration continues to rise, bone lead measurement may be recommended to adequately protect the long-term health of lead workers.

Evaluation of urinary cadmium and lead as markers of background exposure of middle-aged women in Korea: dietary intake as an influential factor

The study was conducted to examine the validity of urinary cadmium (Cd) and lead (Pb) in comparison with the metals in blood as a biological marker of non-occupational exposure of general populations. Participants in four survey sites in Korea (107 non-smoking Korean women aged 30-49 years) offered peripheral blood, morning spot urine, and 24-h total food duplicate samples. Analysis of Cd and Pb was accomplished by graphite furnace atomic absorption spectrophotometry. The analyse levels were evaluated on an individual basis (n = 107) and also on a survey site basis, i.e. in terms of geometric means for the groups in the survey sites (n = 4). Cd in urine (as observed, or after correction for creatinine concentration or a specific gravity) correlated with Cd in blood on an individual as well as survey site basis, and tended to correlate with Cd in food duplicates on the survey site basis. Correlation of Pb in urine with Pb in blood was weaker than that of Cd in urine with Cd in blood both on the individual and survey site basis. Pb in urine correlated with Pb in food duplicates either weakly or even negatively when examined on a survey site basis. It was concluded that Cd in urine can be most probably employed as a biological marker of environmental Cd exposure of general population, whereas less support was obtained for Pb in urine as an exposure marker.

Three new allelic mouse mutations that cause skeletal overgrowth involve the natriuretic peptide receptor C gene (Npr3)

In 1979, a BALB/cJ mouse was identified with an exceptionally long body. This phenotype was found to be caused by a recessive mutation, designated longjohn (lgj), that mapped to the proximal region of chromosome 15. Several years later, a mouse with a similarly elongated body was identified in an outbred stock after chemical mutagenesis with ethylnitrosourea. This phenotype also was caused by a recessive mutation, designated strigosus (stri). The two mutations were found to be allelic. A third allele was identified in a DBA/2J mouse and was designated longjohn-2J (lgj(2J)). Analysis of skeletal preparations of stri/stri mice indicated that the endochondral ossification process was slightly delayed, resulting in an extended proliferation zone. A recent study reported that mice overexpressing brain natriuretic peptide, one of the members of the natriuretic peptide family, exhibit a skeletal-overgrowth syndrome with endochondral ossification defects. The Npr3 gene coding for type C receptor for natriuretic peptides (NPR-C), which is mainly involved in the clearance of the natriuretic peptides, mapped in the vicinity of our mouse mutations and thus was a candidate gene. The present study reports that all three mutations involve the Npr3 gene and provides evidence in vivo that there is a natriuretic-related bone pathway, underscoring the importance of natriuretic peptide clearance by natriuretic peptide type C receptor.

Apolipoprotein E polymorphism in non-diabetic patients with acute coronary syndrome

Since a decade ago, apolipoprotein (apo) E polymorphism has been focussed as a risk factor for cardiovascular disease. ApoE plays a central role as a receptor ligand for the uptake of lipoproteins from the circulation. There was an agreement on apoE polymorphism being one of the major risk factors for coronary artery disease (CAD) by its effects on lipid profiles. However, the effects of apoE have not been noted in all populations and conflicting results in the risk of CAD have been noted. Recently, in situ expression of apoE on the atherosclerotic plaque has been studied. We, therefore, investigated the effects of apoE genotype on patients with acute coronary syndrome, including unstable angina and acute myocardial infarction, in non-diabetic patients. While we could not find significant risk effects of apoE on coronary artery disease and lipid profiles on simple comparison with the normal control group, we could find significantly decreased frequencies of apo epsilon 3 allele in patients with acute coronary syndrome compared with stable angina patients (77.8% vs 88.8%). We suggest that the apoE genotype could be associated with acute coronary events in CAD and further study with in situ biochemical methods will be needed on the effects of apoE polymorphism on plaque stability.

Meta-analysis of trials comparing beta-blockers, calcium antagonists, and nitrates for stable angina

CONTEXT

Which drug is most effective as a first-line treatment for stable angina is not known.

OBJECTIVE

To compare the relative efficacy and tolerability of treatment with beta-blockers, calcium antagonists, and long-acting nitrates for patients who have stable angina.

DATA SOURCES

We identified English-language studies published between 1966 and 1997 by searching the MEDLINE and EMBASE databases and reviewing the bibliographies of identified articles to locate additional relevant studies.

STUDY SELECTION

Randomized or crossover studies comparing antianginal drugs from 2 or 3 different classes (beta-blockers, calcium antagonists, and long-acting nitrates) lasting at least 1 week were reviewed. Studies were selected if they reported at least 1 of the following outcomes: cardiac death, myocardial infarction, study withdrawal due to adverse events, angina frequency, nitroglycerin use, or exercise duration. Ninety (63%) of 143 identified studies met the inclusion criteria.

DATA EXTRACTION

Two independent reviewers extracted data from selected articles, settling any differences by consensus. Outcome data were extracted a third time by 1 of the investigators. We combined results using odds ratios (ORs) for discrete data and mean differences for continuous data. Studies of calcium antagonists were grouped by duration and type of drug (nifedipine vs nonnifedipine).

DATA SYNTHESIS

Rates of cardiac death and myocardial infarction were not significantly different for treatment with beta-blockers vs calcium antagonists (OR, 0.97; 95% confidence interval [CI], 0.67-1.38; P = .79). There were 0.31 (95% CI, 0.00-0.62; P = .05) fewer episodes of angina per week with beta-blockers than with calcium antagonists. beta-Blockers were discontinued because of adverse events less often than were calcium antagonists (OR, 0.72; 95% CI, 0.60-0.86; P<.001). The differences between beta-blockers and calcium antagonists were most striking for nifedipine (OR for adverse events with beta-blockers vs nifedipine, 0.60; 95% CI, 0.47-0.77). Too few trials compared nitrates with calcium antagonists or beta-blockers to draw firm conclusions about relative efficacy.

CONCLUSIONS

beta-Blockers provide similar clinical outcomes and are associated with fewer adverse events than calcium antagonists in randomized trials of patients who have stable angina.

Monophosphoryl lipid A (MPL) upregulates major histocompatibility complex (MHC) class I expression by increasing interferon-gamma (IFN-gamma)

Tumor immunity is primarily mediated by cells as CD8+ cytotoxic T lymphocytes (CTL) recognize tumor antigen by MHC class I molecules. But most tumors are associated with a decreased expression of MHC class I to escape the antitumor immunity of the host. Our previous data have demonstrated that MPL has an antitumor effect on metastatic lung cancer of B16 melanoma with enhancing cytotoxicity due to increase of IFN-gamma and IL-2, and decrease of IL-4, which indicates the stimulation of type 1 helper T cells (Th1). To determine the effects of MPL, IFN-gamma, TNF-alpha, and IL-1 alpha on MHC class I expression of B16 melanoma cells, we evaluated the expression of MHC class I molecules with treatments of MPL, IFN-gamma, TNF-alpha, and IL-1 alpha by flow cytometry. The supernatant of MPL-treated spleen cells in vitro upregulated the expression of MHC class I molecules of B16 melanoma cells compared to the control supernatant of spleen cells. The MHC class I expression of B16 melanoma cells treated with IFN-gamma, but not TNF-alpha or IL-1 alpha, increased in a time-dependent manner. In conclusion, MPL upregulated MHC class I expression of B16 melanoma cells by activating spleen cells via IFN-gamma. These data suggest that increased IFN-gamma by MPL is responsible for the upregulation of MHC class I expression to augment cytotoxicity. Therefore, we suggest that MPL could play an important role in immunotherapy.

Epidemiology of eating disordered symptoms in the Korean general population using a Korean version of the Eating Attitudes Test

OBJECTIVE

The purposes of the present study were to estimate the proportion of subjects with a high score on the Korean version of Eating Attitudes Test--26 (KEAT-26), which may provide preliminary data regarding the prevalence rate of eating disorders in the Korean general population, and to further examine the sociocultural hypothesis of eating disorders.

METHOD

Using a multi-stage questionnaire sampling method, we surveyed 3062 subjects (1249 males, 1813 females) from 3896 Korean adults in a nationwide area.

RESULTS

8.5% (260/3062) of subjects scored above the cut-off on the KEAT-26. Their demographic correlates, eating traits, and other characteristics relating to general psychopathology were similar to those of patients with eating disorders and female Caucasian controls in Western countries.

DISCUSSION

These results suggest that changes in various sociocultural aspects have increased the risk of developing eating disorders in Korea, and support the sociocultural hypothesis of eating disorders.

Mutations affecting ligand specificity of the G-protein-coupled receptor for the Saccharomyces cerevisiae tridecapeptide pheromone

Random mutations were generated in the G-protein-coupled receptor (Ste2p) for the tridecapeptide pheromone (alpha-factor) of Saccharomyces cerevisiae. These mutants were screened for variants that responded to antagonists. Because multiple mutations were detected in each mutant receptor recovered from the screen, site-directed mutagenesis was used to create single-site mutant receptors. Three receptors containing mutations F55V, S219P, and S259P were analyzed for their biological responses to various alpha-factor analogs and for their ligand binding profiles. Cells expressing each of the mutant receptors responded to alpha-factor as well as or better than wild-type cells in a growth arrest assay. In contrast, the binding of alpha-factor to the F55V and S219P mutant receptors was at least 10-fold reduced in comparison to wild-type receptor indicating a complex non-linear correlation between binding affinity and biological activity. Cells expressing mutant receptors responded to some normally inactive analogs in biological assays, despite the fact that these analogs had a low affinity for Ste2p. The analysis of these mutant receptors confirms previous findings that the first and sixth transmembrane regions of Ste2p are important for ligand interaction, ligand specificity, and/or receptor activation to initiate the signal transduction pathway. Changes in binding affinity of pheromone analogs to wild-type and mutant receptors indicate that residue 55 of Ste2p is involved with both ligand binding and signal transduction.

Urinary 5-aminolevulinic acid (ALA) adjusted by creatinine: a surrogate for plasma ALA?

5-Aminolevulinic acid (ALA) is the first intermediate substrate in the heme synthetic pathway and is the substrate of aminolevulinic acid dehydratase (ALAD, porphobilinogen synthase). Because lead effectively inhibits ALAD activity, resulting in accumulation of ALA in urine and blood, urinary ALA (ALAU) has been used as a biomarker for lead exposure or early biologic effect of lead. Intraindividual variation in urinary excretion of ALA requires the use of 24-hour urine samples or adjustment of single urine samples by other normalizing variables, such as urinary creatinine concentration. Previous studies of ALAU concentration have used various adjustment methods; however, few have compared creatinine-adjusted ALAU concentration with ALA concentration in plasma (ALAP) from subjects with low (< 30 micrograms/dL) to moderate (< 60 micrograms/dL) levels of blood lead. To determine if creatinine-adjusted ALAU is associated with ALAP, we measured ALAU, ALAP, and urinary creatinine in 65 Korean lead workers with blood lead concentrations in the range of 14-60 micrograms/dL. ALAU, ALAU/creatinine, or ALAU/log creatinine all correlated with ALAP. However, ALAU/creatinine correlated more closely with ALAP based on Spearman's r (rs = 0.40, P, = 0.0009), supporting the use of ALA/creatinine in single urine samples as a surrogate for ALAP.

Experimental hypercholesterolemia induces ultrastructural changes in the elastic laminae of rabbit aortic valve

Atherosclerosis is the most severe problem in the high-pressure systemic circulation and similar changes also occur in the high-pressure loading valve. This study was designed to test the hypothesis that early atherosclerosis, induced by a high cholesterol diet in rabbits, is characterized by significant ultrastructural change in the elastic laminae of the aortic valve. However, it is not known whether this process is also taking place in the cardiac valve at the early stage of atherosclerosis. Animals were fed either a high cholesterol diet (n = 5) or a control diet (n = 5) for 10-12 weeks. Histologic analysis demonstrated that subendothelial thickening and foam-cell infiltration were evident in the arterialis of aortic valves. Confocal microscopy revealed an altered pattern characterized by fragmentation and disorganization of the arterialis elastic laminae of hypercholesterolemic valves. Computerized digital analysis of the images obtained by confocal scanning microscopy demonstrated that compared to normal valves, the arterialis elastic laminae of hypercholesterolemic valves decreased in percentage of their elastin content (29.03 +/- 1.10% vs. 42.94 +/- 1.35%, p = 0.023). Immunohistochemical staining for matrix metalloproteinase-3 (MMP-3) revealed MMP-3 immunoreactivity was increased in hypercholesterolemic valves, predominantly in the arterialis. This study demonstrated that early atherosclerosis, induced by a high cholesterol diet in rabbits, is characterized by significant ultrastructural change in the elastic laminae of the aortic valve. The arterialis endothelium of the aortic valve may be a more atherosclerosis-prone area compared with the ventricularis. The presence of ultrastructural defect in the elastic laminae may play a role in chronic degenerative change and a resultant valvular dysfunction.