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Purpose: To evaluate radiation dose (RD) reduction potential of heart rate-independent dual-focused scan of prospectively electrocardiography (ECG)-triggered computed tomography (CT) for cardiac functional assessment in children with congenital heart disease (CHD), RD and image quality of the scan mode were compared to those of heart rate-dependent single-extended scan., Methods: This study encompassed 1,252 prospectively ECG-triggered pediatric cardiothoracic CT examinations, including single-focused (a reference in matched comparisons), single-extended (younger patients), and dual-focused (older patients) scans. Propensity score matching was used to reduce the confounding effect of age and sex in two matched groups (MPs) (younger MP: single-focused vs. single-extended; older MP: single-focused vs. dual-focused). CT RD, image noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) of the MPs were compared., Results: The effective dose of single-extended (1.4 ± 0.5 mSv) and dual-focused (1.1 ± 0.4 mSv) scans were approximately 2.0-3.2 times higher than (depending on heart rate) and approximately 1.8 times (irrespective of heart rate) that of the age- and sex-matched single-focused scans (0.6 ± 0.2 mSv), respectively. Image noise and SNR of single-extended and dual-focused scans were similar to those of the age- and sex-matched single-focused scans (p values > 0.05). The CNR was also comparable between single-focused and single-extended scans (younger MP) (p > 0.05), but a slightly lower CNR of the dual-focused scans compared to single-focused scans was observed in the older MP (p < 0.02)., Conclusion: For cardiac functional assessment in children with CHD, heart rate-independent dual-focused prospectively ECG-triggered scan can reduce CT RD, especially at lower heart rates, with comparable image quality, compared to heart rate-dependent single-extended scan., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background and Objectives: Although cardiac rehabilitation (CR) is highly recommended in patients with cardiovascular disease (CVD), participation in CR is low mainly due to access barriers. Home-based CR (HBCR) has been recommended to overcome access barriers. Exercise is a core component of CR and should be developed and implemented based on individual characteristics. We aimed to assess physical activity behaviors, exercise preferences, and exercise barriers to understand physical activity characteristics of CVD patients., Methods: Participants were patients between the ages 19 to 75 years with a history of heart failure with reduced ejection fraction (HFrEF) or myocardial infarction (MI). They completed a cross-sectional survey at a tertiary hospital's outpatient clinic from April to June 2021. Survey data included physical activity levels, patterns, preference, and barriers of exercise., Results: Participants (n=189; 143 males, 46 females, 62.1±12.0 years) were diagnosed as either HFrEF (n=160, 84.7%) or a history of MI (n=97, 51.3%). Only 26.5% of patients engaged in moderate to vigorous exercise for more than 150 minutes per week. Participants preferred exercising alone or with families. Walking (65.6%) and resistance exercises (35.4%) were favored, with outdoor (37%) and home-based (30.2%) settings preferred over fitness centers (10.6%) and hospitals (0.5%). Barriers to exercise included fatigue (34.4%), poor health perception (31.7%), and low fitness levels (30.7%)., Conclusions: The results of this study can be used to develop tailored HBCR programs that consider individual preferences and address specific barriers, facilitating adequate physical activity engagement., Competing Interests: The authors have no financial conflicts of interest., (Copyright © 2024. The Korean Society of Cardiology.)

The role of preoperative cardiac computed tomography (CT) in neonates with pulmonary atresia and intact ventricular septum (PA-IVS) remains unclear. This study was aimed to elaborate the role of preoperative CT-derived anatomical and functional findings in planning treatment strategies in neonates with PA-IVS. The presence of ventriculocoronary arterial connections was evaluated by CT. CT-derived ventricular volumetric parameters were compared and correlated with echocardiographic tricuspid valve (TV) z-score in 12 neonates with PA-IVS. Cardiac CT and echocardiographic findings were compared between definite surgical types (median follow-up, 4 years). Ventriculocoronary arterial connections were identified with CT in 58.3% of cases (7/12) and associated with higher incidence of Fontan procedure (42.9%, 3/7) and high mortality (28.6%, 2/7). The CT-derived and echocardiographic TV z-scores exhibited a high correlation (R = 0.924, p < 0.001). The CT-derived right ventricle (RV) volume and RV-left ventricle volume ratio also displayed high correlations (R = 0.875 and 0.867, respectively; p < 0.001) with echocardiographic TV z-score. More positive echocardiographic TV z-score, high CT-derived RV end-diastolic volume and RV-left ventricle volume ratio, and low CT-derived left ventricular end-diastolic volume were observed in biventricular surgery group (N = 2), compared to Fontan operation (N = 3) and 1.5 ventricular surgery (N = 3) groups, and mortality cases (N = 3). Preoperative CT-derived coronary artery anatomy and ventricular volumetric parameters may supplement treatment planning in neonates with PA-IVS especially when multifactorial decision including echocardiographic TV z-score is in a gray zone.W., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: Cardiac rehabilitation (CR) is recommended for patients with cardiovascular disease. However, the participation and completion rates for hospital-based CR are low, and home-based CR has been suggested as an alternative. This study aimed to develop a home-based CR program and assess the feasibility of the program over a 6-week period in patients with left ventricular dysfunction or a history of myocardial infarction., Methods: This feasibility study consisted of two phases. The initial phase (Study 1) focused on developing the home-based exercise protocol. Systematic approaches to developing evidence-based home-based exercise intervention were implemented including systematic review, patient surveys, and expert consensus. Study 2 aimed to evaluate the feasibility of a 6-week home-based CR program that was based on the results of Study 1. Study 2 included two exercise education sessions and four telephone counseling sessions. During this stage of the exercise program, the participants exercised on two separate days and their experiences while performing the aerobic and resistance exercises were surveyed. Eight participants participated in Study 1 and 16 participated in Study 2., Results: Participants expressed overall satisfaction with the exercise program in Study 1. Heart rate increased in response to exercise, but this did not correspond with perceived exertion. The aim of the home-based CR exercise program was for participants to achieve exercise goals (≥150 min/week of aerobic type exercises as well as at least twice weekly resistance exercise using own body weights). We aimed to increase compliance and adherence to the home-based CR program. In Study 2, 13 out of 16 participants (81.3%) completed the 6-week home-based CR program, with a participation rate of 100% in both exercise education and phone counseling sessions. Adherence to the home-based exercise protocol was 83.1% and no serious adverse events were observed. At the beginning of the study, only three out of 13 participants (23.1%) met the requirements for both aerobic and resistance exercises, but at the end of the 6-week program, 10 out of 13 participants (76.9%) fulfilled the requirements., Conclusion: The exercise program developed in this study was safe and feasible, and the 6-week home-based CR program was feasible for patients with cardiovascular disease without any reported adverse effects., (© 2024. The Author(s).)

Although increase in physical activity is important to improve prognosis of cardiac patients in addition to hospital-based exercise cardiac rehabilitation, their physical activity levels are not properly understood. This study aimed to examine domain- and intensity-specific physical activity in individuals with coronary heart disease (CHD) and compare them with non-CHD individuals. Data from the Korean National Health and Nutrition Examination Survey (KNHANES) from 2014 to 2019 were analyzed, including 1083 CHD patients and 38,532 non-CHD individuals. The inclusion criteria were age 19 years or older and data not missing for CHD information. Before and after propensity score matching (PSM) for age, sex, body mass index, education, household income, alcohol intake, and smoking status, domain (leisure, work, transportation)-and intensity (moderate, vigorous) -specific physical activity participation levels were compared between individuals with and without CHD. Before PSM, CHD individuals were older, less educated, more sedentary, and participated less in PAs compared to non-CHD individuals. After PSM, CHD individuals had similar levels of domain-specific PAs. However, they had higher work-related PA levels (29.7 ± 209.6 vs. 42.1 ± 291.3 min/week p = 0.022) and more sedentary time (487.2 ± 224.2 vs. 514.1 ± 228.7. p = 0.003) than those without CHD. Subgroup analysis revealed lower leisure-related PA in men with CHD (63.5 ± 165.5 vs. 47.3 ± 140.2, p < 0.05) and higher work-related PA in women with CHD (18.9 ± 159.7 vs. 57.1 ± 397.5, p < 0.01). Among those < 65 years of age, individuals with CHD spent more time sedentary than individuals without CHD. CHD individuals are not physically inactive compared with non-CHD individuals who are similar in sociodemographic status and lifestyle. CHD patients' PA levels may have been underestimated., (© 2024. The Author(s).)

Introduction: Carfilzomib plus dexamethasone (Kd) is widely used in patients with relapsed and/or refractory multiple myeloma (RRMM). However, the treatment outcomes of Kd, especially in trial-unfit patients, have not been extensively studied in the real-world setting., Methods: We analyzed the outcomes of 152 RRMM patients who received Kd at our hospitals from April 2018 to March 2022., Results: At the commencement of Kd, patients received a median of two (range 1-7) lines of prior anti-myeloma therapy. According to the ENDEAVOR study criteria, 93 (61.2%) and 59 (38.8%) patients were classified as the trial-fit and the trial-unfit group, respectively. The overall response (OR) rate for the entire cohort was 71.1% (95% CI 63.2-78.1%). Progression-free survival (PFS) and overall survival (OS) were 5.6 months (95% CI 3.9-6.9 months) and 24.0 months (95% CI 13.4-38.0 months), respectively. There was no significant difference in the OR rate between the trial-fit and the trial-unfit groups (76.3% vs. 62.7%; P = 0.105). However, the median PFS (3.6 months vs. 7.3 months; P < 0.001) and OS (15.0 vs. 36.8 months; P = 0.009) were significantly shorter in the trial-unfit group. On multivariate analysis, trial-fitness (unfit vs. fit) remained a significant covariate influencing the TRM (HR: 4.84, 95% CI 1.66-14.06; P = 0.004) and PFS (HR: 1.82, 95% CI 1.27-2.62; P = 0.001)., Conclusion: Our data suggest that the treatment outcomes of Kd are acceptable in the real-world setting with significant differences between the trial-fit and the trial-unfit groups, although they are relatively inferior to those of a pivotal trial., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background and Aim: Although resting heart rate (RHR) is associated with prevalence and incidence of diabetes, whether it is associated with undiagnosed diabetes is still unclear. We aimed to investigate whether the RHR is associated with the prevalence of undiagnosed diabetes in a large Korean national dataset., Methods and Results: The Korean National Health and Nutrition Examination Survey data from 2008 to 2018 were used. After screening, 51,637 participants were included in this study. The odds ratios and 95% confidence intervals (CIs) for undiagnosed diabetes were calculated using multivariable-adjusted logistic regression analyses. Analyses showed that participants with a RHR of ≥90 bpm showed a 4.00- (95% CI: 2.77-5.77) and 3.21-times (95% CI: 2.01-5.14) higher prevalence of undiagnosed diabetes for men and women, respectively, than those with a RHR of <60 bpm. The linear dose-response analyses showed that each 10-bpm increment in RHR was associated with a 1.39- (95% CI: 1.32-1.48) and 1.28-times (95% CI: 1.19-1.37) higher prevalence of undiagnosed diabetes for men and women, respectively. In the stratified analyses, the positive association between RHR and the prevalence of undiagnosed diabetes was tended to be stronger among those who were younger (age: <40 years) and lean (BMI: <23 kg/m 2 )., Conclusions: Elevated RHR was significantly associated with a higher prevalence of undiagnosed diabetes in Korean men and women, independent of demographic, lifestyle, and medical factors. Accordingly, the value of RHR as a clinical indicator and health marker, especially in reducing the prevalence of undiagnosed diabetes, is suggestible., Competing Interests: Declaration of competing interest The authors declare that they have no conflicts of interest., (Copyright © 2022 The Italian Diabetes Society, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition and the Department of Clinical Medicine and Surgery, Federico II University. Published by Elsevier B.V. All rights reserved.)

South Korea has developed its first Para Report Card on physical activity (PA) for children and adolescents with disabilities. Five national surveillance databases were used to evaluate PA indicators based on the benchmarks and grading rubric provided by Active Healthy Kids Global Alliance. Report card evaluation committees were invited to grade and assess the results using strengths, weaknesses, opportunities, and threats analysis. Five indicators (overall PA, D+; organized sports and PA, D-; active transportation, D-; physical fitness, D+; and government, A+) and one additional indicator (sleep, C-) were assigned a letter grade. The other five indicators were graded as incomplete. The Para Report Card revealed a significant gap between the behavioral-indicator grades (D- to D+) and the policy-indicator grade (A+), suggesting that government strategies and investment have not yet been translated into behavioral PA among children and adolescents with disabilities.

Background Current understanding of metabolic heart disease consists of a myriad of different pathophysiological mechanisms. Epicardial adipose tissue (EAT) is increasingly recognized as metabolically active and associated with adverse cardiovascular outcomes. The present study aimed to investigate the effect of increased EAT volume index on left ventricular (LV) myocardial fat content and burden of interstitial myocardial fibrosis and their subsequent effects on LV myocardial contractile function. Methods and Results A total of 40 volunteers (mean age, 35±10 years; 26 males) of varying body mass index (25.0±4.1 kg/m 2 ; range, 19.3-36.3 kg/m 2 ) and without diabetes mellitus or hypertension were prospectively recruited. EAT volume index, LV myocardial fat content, and extracellular volume were quantified by magnetic resonance imaging. LV myocardial contractile function was quantified by speckle tracking echocardiography global longitudinal strain on the same day as magnetic resonance imaging examination. Mean total EAT volume index, LV myocardial fat content, and extracellular volume were 30.0±19.6 cm 3 /m 2 , 5.06%±1.18%, and 27.5%±0.5%, respectively. On multivariable analyses, increased EAT volume index and insulin resistance were independently associated with both increased LV myocardial fat content content and higher burden of interstitial myocardial fibrosis. Furthermore, increased EAT volume index was independently associated with LV global longitudinal strain. Conclusions Increased EAT volume index and insulin resistance were independently associated with increased myocardial fat accumulation and interstitial myocardial fibrosis. Increased EAT volume index was associated with detrimental effects on myocardial contractile function as evidenced by a reduction in LV global longitudinal strain.

Background: Although epicardial adipose tissue (EAT) volume is associated with increased incidence of coronary artery disease (CAD), its role in myocardial systolic dysfunction is unclear. The present study aimed to identify independent determinants of EAT volume in patients without obstructive CAD, and to evaluate the association between EAT volume (vs other measures of obesity) and myocardial systolic strain analysis., Methods: We prospectively recruited 130 patients without obstructive CAD on contrast-enhanced cardiac computed tomography imaging and normal left ventricular ejection fraction on 3-dimensional (3D) echocardiography. EAT volume was quantified from cardiac computed tomography imaging, and 3D multidirectional (longitudinal, circumferential, radial, and area) strain were measured., Results: The mean EAT volume was 97.5 ± 43.7 cm 3 . In multivariable analysis, measures of obesity (body mass index [P = 0.007] and waist/hip ratio [P = 0.001]) were independently associated with larger EAT volume. EAT volume was correlated with 3D global longitudinal (r = 0.601; P < 0.001), circumferential (r = 0.375; P < 0.001), radial (r = -0.546; P < 0.001), and area (r = 0.558; P < 0.001) strain. In multivariable analyses, epicardial fat volume was the strongest predictor of 3D global longitudinal (standardized β = 0.512; P < 0.001), circumferential (standardized β = 0.242; P = 0.006), radial (standardized β = -0.422; P < 0.001), and area (standardized β = 0.428; P < 0.001) strain. In contrast, other measures of obesity including body mass index and waist/hip ratio were not independent determinants of 3D multidirectional global strain (all P > 0.05)., Conclusions: EAT volume is independently associated with impaired myocardial systolic function despite preserved 3D left ventricular ejection fraction and absence of obstructive CAD, and might play a significant role in the pathophysiology of diabetic, obesity, and metabolic heart disease., (Copyright © 2016 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.)

Purpose: To define intramyocardial triglyceride (TG), creatine (Cr), and choline (Cho) in healthy volunteers, and determine the feasibilities, scan durations and agreements between cardiac proton magnetic resonance spectroscopy ([(1)H]-MRS) performed with fewer signal averages versus a reference standard with 128 signal averages., Materials and Methods: Thirty-one participants underwent [(1)H]-MRS using 16, 32, 64, and 128 signal averages. Intramyocardial TG, Cr, or Cho contents relative to water were calculated and expressed as a percentage., Results: Mean intramyocardial TG, Cr, and Cho were 1.30 ± 1.13, 0.19 ± 0.18, and 0.24 ± 0.28%, respectively. The feasibilities for quantifying intramyocardial TG, Cr, and Cho using fewer signal averages ranged from 93.5 to 100, 90.3 to 93.5, and 90.3 to 96.8%, respectively. Scan durations for 16, 32, 64, and 128 signal averages were 1.1 ± 0.5, 2.6 ± 0.9, 5.9 ± 2.0, and 13.2 ± 4.5 min, respectively (p < 0.001). Agreements with the reference standard 128 signal average was higher for quantification of intramyocardial TG compared to Cr and Cho., Conclusion: Quantification of intramyocardial TG with [(1)H]-MRS with only 64 signal averages was highly feasible, showed excellent agreement with 128 signal averages, and had significantly shorter scan duration. By contrast, quantifying Cr and Cho using fewer signal averages had lower feasibilities and agreements compared to 128 signal averages.

Trichomonas vaginalis commonly causes vaginitis and perhaps cervicitis in women and urethritis in men and women. Macrophages are important immune cells in response to T. vaginalis infection. In this study, we investigated whether human macrophages could be involved in inflammation induced by T. vaginalis. Human monocyte-derived macrophages (HMDM) were co-cultured with T. vaginalis. Live, opsonized-live trichomonads, and T. vaginalis lysates increased proinflammatory cytokines, such as TNF-alpha, IL-1beta, and IL-6 by HMDM. The involvement of nuclear factor (NF)-kappaB signaling pathway in cytokine production induced by T. vaginalis was confirmed by phosphorylation and nuclear translocation of p65 NF-kappaB. In addition, stimulation with live T. vaginalis induced marked augmentation of nitric oxide (NO) production and expression of inducible NO synthase (iNOS) levels in HMDM. However, trichomonad-induced NF-kappaB activation and TNF-alpha production in macrophages were significantly inhibited by inhibition of iNOS levels with L-NMMA (NO synthase inhibitor). Moreover, pretreatment with NF-kappaB inhibitors (PDTC or Bay11-7082) caused human macrophages to produce less TNF-alpha. These results suggest that T. vaginalis stimulates human macrophages to produce proinflammatory cytokines, such as IL-1, IL-6, and TNF-alpha, and NO. In particular, we showed that T. vaginalis induced TNF-alpha production in macrophages through NO-dependent activation of NF-kappaB, which might be closely involved in inflammation caused by T. vaginalis.

Vibrio vulnificus is a Gram-negative bacterium that multiplies rapidly in host tissue and causes extensive tissue damage. Human peripheral blood mononuclear cells (PBMC) were shown to be readily killed by exposure to live V. vulnificus. V. vulnificus induced production of intracellular reactive oxygen species (ROS) and nitric oxide (NO) in PBMC. Pretreatment of PBMC with diphenyleneiodonium chloride (DPI) abolished ROS generation upon exposure to V. vulnificus and decreased the bacterial ability to cause cell death. In contrast, pretreatment of these cells with inhibitors of inducible nitric oxide synthase (iNOS) blocked V. vunificus-induced NO production, but did not significantly alter cell death by V. vulnificus. V. vulnificus also triggered phosphorylation of mitogen-activated protein kinases (MAPKs), including p38 and ERK1/2 in PBMC. Inactivation of these MAPKs by selective inhibitors caused a reduction both in ROS generation and cell death induced by V. vulnificus. It was further shown that an inhibitor of ROS generation (DPI) blocked V. vulnificus-induced phosphorylation of p38 and ERK1/2 MAPK. This study demonstrates that V. vulnificus induces death of PBMC via ROS-dependent activation of p38 MAPK and ERK1/2 MAPK.

Vibrio vulnificus, a pathogenic bacterium causing primary septicemia, exhibited cytotoxicity towards Jurkat cells of T-lymphocytes through intracellular reactive oxygen species (ROS) production. Pretreatment of Jurkat T-cells with diphenyleneiodonium chloride (DPI) abolished V. vulnificus-induced ROS generation and bacterial ability to cause cell death. Jurkat T-cells expressing dominant-negative protein of Rac subunit of NADPH oxidase (NOX) did not show increased ROS production and cell death by V. vulnificus. Vibrio vulnificus also triggered phosphorylation of mitogen-activated protein kinases (MAPKs) including p38 and ERK1/2 in Jurkat T-cells. Experiments using inhibitors or small interfering RNAs for each MAPK showed that both MAPKs are involved in V. vulnificus-induced cell death. DPI only blocked the phosphorylation of p38 MAPK in Jurkat T-cells exposed by V. vulnificus. This study demonstrates that V. vulnificus induces death of Jurkat T-cells via ROS-dependent activation of p38 MAPK, and that NOX plays a major role in ROS generation in V. vulnificus-exposed cells.

Vibrio vulnificus is a pathogenic bacterium causing primary septicemia, which follows a classical septic shock pathway, including an overwhelming inflammatory cytokine response. In this study, we identified a putative lipoprotein of V. vulnificus, encoded by the ilpA gene, as one of the surface proteins that specifically reacted with the antibodies raised against outer membrane proteins of V. vulnificus. Using a mutant V. vulnificus in which its ilpA gene was knocked out, we found that IlpA is important in the production of interferon-gamma in human peripheral blood mononuclear cells. Production of tumor necrosis factor-alpha and interleukin-6 is also induced by the recombinant IlpA (rIlpA) in human monocytes. Lipidation of the rIlpA was observed by in vivo labeling in Escherichia coli. Experiments using the mutant IlpA, which is unable to be modified by lipidation, indicate that the lipid moiety of this protein has an essential property for cytokine production in human cells. Pretreatment of monocytes with antibodies against Toll-like receptor 2 (TLR2) inhibited production of both tumor necrosis factor-alpha and interleukin-6. The role of TLR2 in IlpA-induced cytokine production was confirmed by an in vitro assay, in which only the TLR2-expressing cells showed a dramatic induction of nuclear factor-kappaB activity by rIlpA. In addition, rIlpA treatment resulted in induction of TLR2 transcription in human cells. In comparison with the wild type V. vulnificus, the ilpA mutant showed a reduced mortality in mice. These results demonstrate that IlpA of V. vulnificus functions as an immunostimulant to human cells via TLR2.

Vibrio vulnificus is a pathogenic bacterium that causes gastroenteritis and primary septicemia. To identify factors involved in microbial adherence to the host cells, we investigated bacterial proteins capable of binding to fibronectin, one of the main components comprised of the extracellular matrix of mammalian cells. A protein of approximately 35 kDa was purified from the extracts of V. vulnificus by its property to bind to immobilized fibronectin. This protein was identified as OmpU, one of the major outer membrane proteins of V. vulnificus. In binding assays using immobilized fibronectin, the number of ompU mutant cells bound to fibronectin was only 4% of that of wild-type cells bound to fibronectin. In addition, the exogenous addition of antibodies against OmpU resulted in a decreased ability of wild-type V. vulnificus to adhere to fibronectin. The ompU mutant was also defective in its adherence to RGD tripeptide (5% of the adherence of the wild type to RGD), cytoadherence to HEp-2 cells (7% of the adherence of the wild type to HEp-2), cytotoxicity to cell cultures (39% of the cytotoxicity of the wild type), and mortality in mice (10-fold increase in the 50% lethal dose). The ompU mutant complemented with the intact ompU gene restored its abilities for adherence to fibronectin, RGD tripeptide, and HEp-2 cells; cytotoxicity to HEp-2 cells; and mouse lethality. This study indicates that OmpU is an important virulence factor involved in the adherence of V. vulnificus to the host cells.

A cDNA clone encoding a putative Bop1 homologous protein was identified in Giardia lamblia. Since Bop1 is a nucleolar protein involved in rRNA processing, thereby controlling the cell cycle, we investigated components of cell cycle control in G. lamblia by identifying the protein(s) that interact with Bop 1. Through an immunoaffinity column made with polyclonal antibodies specific to the recombinant Bop1 of G. lamblia, a pool of proteins was obtained from the crude extracts of Giardia and then used as antigens to immunize rats. By employing the resultant sera for cDNA library immunoscreening, we isolated cDNA clones encoding an immunopurified protein, which turned out to contain the gene for beta-giardin, a Giardia-specific cytoskeletal protein. The interaction between Bop1 and beta-giardin was confirmed via two different methods, yeast two-hybrid assay and coimmunoprecipitation.