Glucose/Fructose Delivery to the Distal Nephron Activates the Sodium-Chloride Cotransporter via the Calcium-Sensing Receptor.

BACKGROUND: The calcium-sensing receptor (CaSR) in the distal convoluted tubule (DCT) activates the NaCl cotransporter (NCC). Glucose acts as a positive allosteric modulator of the CaSR. Under physiologic conditions, no glucose is delivered to the DCT, and fructose delivery depends on consumption. We hypothesized that glucose/fructose delivery to the DCT modulates the CaSR in a positive allosteric way, activating the WNK4-SPAK-NCC pathway and thus increasing salt retention. METHODS: We evaluated the effect of glucose/fructose arrival to the distal nephron on the CaSR-WNK4-SPAK-NCC pathway using HEK-293 cells, C57BL/6 and WNK4-knockout mice, ex vivo perfused kidneys, and healthy humans. RESULTS: HEK-293 cells exposed to glucose/fructose increased SPAK phosphorylation in a WNK4- and CaSR-dependent manner. C57BL/6 mice exposed to fructose or a single dose of dapagliflozin to induce transient glycosuria showed increased activity of the WNK4-SPAK-NCC pathway. The calcilytic NPS2143 ameliorated this effect, which was not observed in WNK4-KO mice. C57BL/6 mice treated with fructose or dapagliflozin showed markedly increased natriuresis after thiazide challenge. Ex vivo rat kidney perfused with glucose above the physiologic threshold levels for proximal reabsorption showed increased NCC and SPAK phosphorylation. NPS2143 prevented this effect. In healthy volunteers, cinacalcet administration, fructose intake, or a single dose of dapagliflozin increased SPAK and NCC phosphorylation in urinary extracellular vesicles. CONCLUSIONS: Glycosuria or fructosuria was associated with increased NCC, SPAK, and WNK4 phosphorylation in a CaSR-dependent manner.

Deep mutational scanning of hemagglutinin helps predict evolutionary fates of human H3N2 influenza variants.

Human influenza virus rapidly accumulates mutations in its major surface protein hemagglutinin (HA). The evolutionary success of influenza virus lineages depends on how these mutations affect HA's functionality and antigenicity. Here we experimentally measure the effects on viral growth in cell culture of all single amino acid mutations to the HA from a recent human H3N2 influenza virus strain. We show that mutations that are measured to be more favorable for viral growth are enriched in evolutionarily successful H3N2 viral lineages relative to mutations that are measured to be less favorable for viral growth. Therefore, despite the well-known caveats about cell-culture measurements of viral fitness, such measurements can still be informative for understanding evolution in nature. We also compare our measurements for H3 HA to similar data previously generated for a distantly related H1 HA and find substantial differences in which amino acids are preferred at many sites. For instance, the H3 HA has less disparity in mutational tolerance between the head and stalk domains than the H1 HA. Overall, our work suggests that experimental measurements of mutational effects can be leveraged to help understand the evolutionary fates of viral lineages in nature-but only when the measurements are made on a viral strain similar to the ones being studied in nature.

Anti-adipogenic and anti-diabetic effects of cis-3',4'-diisovalerylkhellactone isolated from Peucedanum japonicum Thunb leaves in vitro.

Peucedanum japonicum Thunb is a medicinal plant belonging to the family Umbelliferae. This study evaluated the anti-diabetic and anti-obesity effects of cis-3',4'-diisovalerylkhellactone (cDIVK) isolated from Peucedanum japonicum Thunb leaves. cDIVK (30 and 50µM) effectively inhibited adipocyte differentiation and fat accumulation, whereas it stimulated glucose uptake compared with the control in 3T3-L1 cells. cDIVK significantly increased AMPK activation and suppressed protein and mRNA expression of major adipogenic transcriptional factors such as C/EBPα, PPARγ and SREBP-1c in 3T3-L1 cells. In addition, cDIVK had potential α-glucosidase inhibitory activity. These results indicated that cDIVK may act as a natural dual therapeutic agent for diabetes and obesity.

Production of novel vinegar having antioxidant and anti-fatigue activities from Salicornia herbacea L.

BACKGROUND: Salicornia herbacea L. is a halophyte that grows in salt marshes and contains significant amounts of salts and minerals. Because it is known as a folk medication to treat diseases, various processed products such as powder, globular type of powder, laver and extract have been developed. However, it is difficult to process as a drink because of its high salinity. In the present study, glasswort vinegar (GV) containing high amounts of organic acids and minerals was developed via two-step fermentation with unpolished rice substrates and investigated its antioxidant and anti-fatigue activities. RESULTS: GV showed various free radical scavenging effects, reducing power, oxidized-LDL inhibition and superoxide dismutase-like activities. Compared with the control group (orally administered 7 g kg(-1) distilled water), the GV supplementation group showed increased running endurance and had higher glycogen accumulation in liver and muscles of rats exhausted by exercise. Furthermore, the GV-administered group demonstrated significantly elevated lactate and ATP metabolism, promoting enzyme activities such as muscle creatine kinase and lactate dehydrogenase, whereas serum fatigue biomarkers such as ammonia, lactate and inorganic acid were markedly decreased. CONCLUSION: These results indicate that GV can be used as a functional food for the development of a dietary beverage to alleviate fatigue.

Sensitization of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-resistant primary prostate cancer cells by isoegomaketone from Perilla frutescens.

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is currently in clinical trials as a cancer treatment due to its ability to induce apoptosis selectively in cancer cells. Nevertheless, the risk of developing resistance warrants the development of sensitizers that can overcome resistance to TRAIL. In this study, isoegomaketone (1) acted as a synergistic TRAIL sensitizer by mediating up-regulation of DR5 expression in primary prostate cancer RC-58T/h/SA#4 cells. Combined with 1, TRAIL exhibited enhanced apoptotic activity in a human prostate cancer cell line designated RC-58T/h/SA#4, as indicated by increases in annexin V-positive and sub-G1 cell populations as well as condensation of chromatin or apoptotic bodies. Combined treatment also activated caspases-8, -9, and -3; increased the protein levels of Bax, AIF, and cytosolic cytochrome c; and induced PARP cleavage while reducing Bcl-2 protein expression. Human recombinant DR5 Fc chimera efficiently attenuated 1-induced apoptosis, thereby demonstrating the critical role of DR5 in 1-mediated apoptotic cell death. Furthermore, DR5 expression induced by 1 was mediated via a ROS-independent pathway that required CHOP and p53. Overall, these findings provide evidence that 1 potentiates TRAIL-mediated apoptosis through up-regulation of DR5 via a ROS-independent pathway. This suggests that 1 has potential for increasing the effectiveness of prostate cancer therapy with TRAIL.

Genomic Analysis and Tracking of SARS-CoV-2 Variants in Gwangju, South Korea, From 2020 to 2022.

BACKGROUND: Since severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was first reported in Wuhan, China, in December 2019, it has spread rapidly, and many coronavirus disease (COVID-19) cases have occurred in Gwangju, South Korea. Viral mutations following the COVID-19 epidemic have increased interest in the characteristics of epidemics in this region, and pathogen genetic analysis is required for infection control and prevention. METHODS: In this study, SARS-CoV-2 whole-genome analysis was performed on samples from patients with COVID-19 in Gwangju from 2020 to 2022 to identify the trends in COVID-19 prevalence and to analyze the phylogenetic relationships of dominant variants. B.41 and B.1.497 prevailed in 2020, the early stage of the COVID-19 outbreak; then, B.1.619.1 mainly occurred until June 2021. B.1.617.2, classified as sublineages AY.69 and AY.122, occurred continuously from July to December 2021. Since strict measures to strengthen national quarantine management had been implemented in South Korea until this time, the analysis of mutations was also able to infer the epidemiological relationship between infection transmission routes. Since the first identification of the Omicron variant in late December 2021, the spread of infection has been very rapid, and weekly whole-genome analysis of specimens has enabled us to monitor new Omicron sublineages occurring in Gwangju. CONCLUSIONS: Our study suggests that conducting regional surveillance in addition to nation-level genomic surveillance will enable more rapid and detailed variant surveillance, which will be helpful in the overall prevention and management of infectious diseases.

Age-dependent heterogeneity in the antigenic effects of mutations to influenza hemagglutinin.

Human influenza virus evolves to escape neutralization by polyclonal antibodies. However, we have a limited understanding of how the antigenic effects of viral mutations vary across the human population and how this heterogeneity affects virus evolution. Here, we use deep mutational scanning to map how mutations to the hemagglutinin (HA) proteins of two H3N2 strains, A/Hong Kong/45/2019 and A/Perth/16/2009, affect neutralization by serum from individuals of a variety of ages. The effects of HA mutations on serum neutralization differ across age groups in ways that can be partially rationalized in terms of exposure histories. Mutations that were fixed in influenza variants after 2020 cause greater escape from sera from younger individuals compared with adults. Overall, these results demonstrate that influenza faces distinct antigenic selection regimes from different age groups and suggest approaches to understand how this heterogeneous selection shapes viral evolution.

Age-dependent heterogeneity in the antigenic effects of mutations to influenza hemagglutinin.

Human influenza virus evolves to escape neutralization by polyclonal antibodies. However, we have a limited understanding of how the antigenic effects of viral mutations vary across the human population, and how this heterogeneity affects virus evolution. Here we use deep mutational scanning to map how mutations to the hemagglutinin (HA) proteins of the A/Hong Kong/45/2019 (H3N2) and A/Perth/16/2009 (H3N2) strains affect neutralization by serum from individuals of a variety of ages. The effects of HA mutations on serum neutralization differ across age groups in ways that can be partially rationalized in terms of exposure histories. Mutations that fixed in influenza variants after 2020 cause the greatest escape from sera from younger individuals. Overall, these results demonstrate that influenza faces distinct antigenic selection regimes from different age groups, and suggest approaches to understand how this heterogeneous selection shapes viral evolution.

Celastrol inhibits growth and induces apoptotic cell death in melanoma cells via the activation ROS-dependent mitochondrial pathway and the suppression of PI3K/AKT signaling.

Celastrol has been reported to possess anticancer effects in various cancers; however, the precise mechanism underlying ROS-mediated mitochondria-dependent apoptotic cell death triggered by celastrol treatment in melanoma cells remains unknown. We showed that celastrol effectively induced apoptotic cell death and inhibited tumor growth using tissue culture and in vivo models of B16 melanoma. In addition to apoptotic cell death in B16 cells, several apoptotic events such as PARP cleavage and activation of caspase were confirmed. Pretreatment with caspase inhibitor modestly attenuated the celastrol-induced increase in PARP cleavage and sub-G1 cell population, implying that caspases play a partial role in celastrol-induced apoptosis. Moreover, ROS generation was detected following celastrol treatment. Blocking of ROS accumulation with ROS scavengers resulted in inhibition of celastrol-induced Bcl-2 family-mediated apoptosis, indicating that celastrol-induced apoptosis involves ROS generation as well as an increase in the Bax/Bcl-2 ratio leading to release of cytochrome c and AIF. Importantly, silencing of AIF by transfection of siAIF into cells remarkably attenuated celastrol-induced apoptotic cell death. Moreover, celastrol inhibited the activation of PI3K/AKT/mTOR signaling cascade in B16 cells. Our data reveal that celastrol inhibits growth and induces apoptosis in melanoma cells via the activation of ROS-mediated caspase-dependent and -independent pathways and the suppression of PI3K/AKT signaling.

Efficiency of a dexamethasone nanosuspension as an intratympanic injection for acute hearing loss.

Dexamethasone sodium phosphate (Dex-SP) is the most commonly used drug administered via intratympanic injection for the treatment of acute hearing loss, but its penetration efficiency into the inner ear is very low. To address this problem, we evaluated the possibility of administering dexamethasone nanosuspensions via intratympanic injection because hydrophobic drugs might be more effective in penetrating the inner ear. Three types of dexamethasone nanosuspensions were prepared; the dexamethasone nanoparticles in the three nanosuspensions were between approximately 250 and 350 nm in size. To compare the efficiency of Dex-SP and dexamethasone nanosuspension in delivering dexamethasone to the inner ear, the concentrations of dexamethasone in perilymph and cochlear tissues were compared by liquid chromatography-mass spectrometry. The dexamethasone nanosuspensions resulted in significantly higher drug concentrations in perilymph and cochlear tissues than Dex-SP at 6 h; interestingly, animals treated with nanosuspensions showed a 26-fold higher dexamethasone concentrations in their cochlear tissues than animals treated with Dex-SP. In addition, dexamethasone nanosuspension caused better glucocorticoid receptor phosphorylation than Dex-SP both in vitro and in vivo, and in the ototoxic animal model, the nanosuspension showed a significantly better hearing-protective effect against ototoxic drugs than Dex-SP. In the in vivo safety evaluation, the nanosuspension showed no toxicity at concentrations up to 20 mg/mL. In conclusion, a nanosuspension of dexamethasone was able to deliver dexamethasone to the cochlea very safely and efficiently and showed potential as a formula for intratympanic injection.

Association of Physician Orders for Life-Sustaining Treatment With Inpatient Antimicrobial Use at End of Life in Patients With Cancer.

BACKGROUND: Antimicrobial utilization at end of life is common, but whether advance directives correlate with usage is unknown. We sought to determine whether Washington State Physician Orders for Life Sustaining Treatment (POLST) form completion or antimicrobial preferences documented therein correlate with subsequent inpatient antimicrobial prescribing at end of life. METHODS: This was a single-center, retrospective cohort study of adult patients at a cancer center who died between January 1, 2016, and June 30, 2019. We used negative binomial models adjusted for age, sex, and malignancy type to test the relationship between POLST form completion ≥30 days before death, antimicrobial preferences, and antimicrobial days of therapy (DOT) per 1000 inpatient-days in the last 30 days of life. RESULTS: Among 1295 eligible decedents with ≥1 inpatient-day during the last 30 days of life, 318 (24.6%) completed a POLST form. Of 318, 120 (37.7%) were completed ≥30 days before death, 35/120 (29.2%) specified limited antimicrobials, 55/120 (45.8%) specified full antimicrobial use, and 30/120 (25%) omitted antimicrobial preference. Eighty-three percent (1070/1295) received ≥1 inpatient antimicrobial. The median total and intravenous (IV) antimicrobial DOT/1000 inpatient-days were 1077 and 667. Patients specifying limited antimicrobials had significantly lower total antimicrobial DOT (adjusted incidence rate ratio [IRR], 0.68; 95% CI, 0.49-0.95; P = .02) and IV antimicrobial DOT (IRR, 0.57; 95% CI, 0.38-0.86; P = .008) compared with those without a POLST. CONCLUSIONS: Indicating a preference for limited antimicrobials on a POLST form ≥30 days before death may lead to less inpatient antimicrobial use in the last 30 days of life.

Cell-Culture Adaptation of H3N2 Influenza Virus Impacts Acid Stability and Reduces Airborne Transmission in Ferret Model.

Airborne transmission of seasonal and pandemic influenza viruses is the reason for their epidemiological success and public health burden in humans. Efficient airborne transmission of the H1N1 influenza virus relies on the receptor specificity and pH of fusion of the surface glycoprotein hemagglutinin (HA). In this study, we examined the role of HA pH of fusion on transmissibility of a cell-culture-adapted H3N2 virus. Mutations in the HA head at positions 78 and 212 of A/Perth/16/2009 (H3N2), which were selected after cell culture adaptation, decreased the acid stability of the virus from pH 5.5 (WT) to pH 5.8 (mutant). In addition, the mutant H3N2 virus replicated to higher titers in cell culture but had reduced airborne transmission in the ferret model. These data demonstrate that, like H1N1 HA, the pH of fusion for H3N2 HA is a determinant of efficient airborne transmission. Surprisingly, noncoding regions of the NA segment can impact the pH of fusion of mutant viruses. Taken together, our data confirm that HA acid stability is an important characteristic of epidemiologically successful human influenza viruses and is influenced by HA/NA balance.

Clinical and Virologic Characteristics and Outcomes of Coronavirus Disease 2019 at a Cancer Center.

BACKGROUND: High morbidity and mortality have been observed in patients with cancer and coronavirus disease 2019 (COVID-19); however, there are limited data on antimicrobial use, coinfections, and viral shedding. METHODS: We conducted a retrospective cohort study of adult patients at the Seattle Cancer Care Alliance diagnosed with COVID-19 between February 28, 2020 and June 15, 2020 to characterize antimicrobial use, coinfections, viral shedding, and outcomes within 30 days after diagnosis. Cycle threshold values were used as a proxy for viral load. We determined viral clearance, defined as 2 consecutive negative results using severe acute respiratory syndrome coronavirus 2 reverse-transcription polymerase chain reaction results through July 30, 2020. RESULTS: Seventy-one patients were included with a median age of 61 years; 59% had a solid tumor. Only 3 patients had documented respiratory bacterial coinfection. Empiric antibiotics for pneumonia were prescribed more frequently early in the study period (February 29-March 28, 2020; 12/34) compared to the later period (March 29-June 15, 2020; 2/36) (P = .002). The median number of days from symptom onset to viral clearance was 37 days with viral load rapidly declining in the first 7-10 days after symptom onset. Within 30 days of diagnosis, 29 (41%) patients were hospitalized and 12 (17%) died. Each additional comorbidity was associated with 45% lower odds of days alive and out of hospital in the month following diagnosis in adjusted models. CONCLUSIONS: Patients at a cancer center, particularly those with multiple comorbidities, are at increased risk of poor outcomes from COVID-19. Prolonged viral shedding is frequently observed among cancer patients, and its implications on transmission and treatment strategies warrant further study.

Human Norovirus Replication in Temperature-Optimized MDCK Cells by Forkhead Box O1 Inhibition.

Human noroviruses (HuNoVs) are a leading cause of gastroenteritis outbreaks worldwide. However, the paucity of appropriate cell culture model for HuNoV replication has prevented developing effective anti-HuNoV therapy. In this study, first, the replication of the virus at various temperatures in different cells was compared, which showed that lowering the culture temperature from 37°C significantly increased virus replication in Madin-Darby canine kidney (MDCK) cells. Second, the expression levels of autophagy-, immune-, and apoptosis-related genes at 30°C and 37°C were compared to explore factors affecting HuNoV replication. HuNoV cultured at 37°C showed significantly increased autophagy- (ATG5 and ATG7) and immune- (IFNA, IFNB, ISG15, and NFKB) related genes compared to mock. However, the virus cultured at 30°C showed significantly decreased expression of autophagy- (ATG5 and ATG7) and not significantly different in major immune- (IFNA, ISG15, and NFKB) related genes compared to mock. Importantly, expression of the transcription factor FOXO1, which controls autophagy- and immune-related gene expression, was significantly lower at 30°C. Moreover, FOXO1 inhibition in temperature-optimized MDCK cells enhanced HuNoV replication, highlighting FOXO1 inhibition as an approach for successful virus replication. In the temperature-optimized cells, various HuNoV genotypes were successfully replicated, with GI.8 showing the highest replication levels followed by GII.1, GII.3, and GII.4. Furthermore, ultrastructural analysis of the infected cells revealed functional HuNoV replication at low temperature, with increased cellular apoptosis and decreased autophagic vacuoles. In conclusion, temperature-optimized MDCK cells can be used as a convenient culture model for HuNoV replication by inhibiting FOXO1, providing adaptability to different genotypes.

Different genetic barriers for resistance to HA stem antibodies in influenza H3 and H1 viruses.

The discovery and characterization of broadly neutralizing human antibodies (bnAbs) to the highly conserved stem region of influenza hemagglutinin (HA) have contributed to considerations of a universal influenza vaccine. However, the potential for resistance to stem bnAbs also needs to be more thoroughly evaluated. Using deep mutational scanning, with a focus on epitope residues, we found that the genetic barrier to resistance to stem bnAbs is low for the H3 subtype but substantially higher for the H1 subtype owing to structural differences in the HA stem. Several strong resistance mutations in H3 can be observed in naturally circulating strains and do not reduce in vitro viral fitness and in vivo pathogenicity. This study highlights a potential challenge for development of a truly universal influenza vaccine.

Identification of Antibodies Targeting the H3N2 Hemagglutinin Receptor Binding Site following Vaccination of Humans.

Antibodies targeting the receptor binding site (RBS) of the influenza virus hemagglutinin (HA) protein are usually not broadly reactive because their footprints are typically large and extend to nearby variable HA residues. Here, we identify several human H3N2 HA RBS-targeting monoclonal antibodies (mAbs) that are sensitive to substitutions in conventional antigenic sites and are therefore not broadly reactive. However, we also identify an H3N2 HA RBS-targeting mAb that is exceptionally broadly reactive despite being sensitive to substitutions in residues outside of the RBS. We show that similar antibodies are present at measurable levels in the sera of some individuals but that they are inefficiently elicited by conventional vaccines. Our data indicate that HA RBS-targeting antibodies can be effective against variable viral strains even when they are somewhat sensitive to substitutions in HA residues adjacent to the RBS.

Mapping person-to-person variation in viral mutations that escape polyclonal serum targeting influenza hemagglutinin.

A longstanding question is how influenza virus evolves to escape human immunity, which is polyclonal and can target many distinct epitopes. Here, we map how all amino-acid mutations to influenza's major surface protein affect viral neutralization by polyclonal human sera. The serum of some individuals is so focused that it selects single mutations that reduce viral neutralization by over an order of magnitude. However, different viral mutations escape the sera of different individuals. This individual-to-individual variation in viral escape mutations is not present among ferrets that have been infected just once with a defined viral strain. Our results show how different single mutations help influenza virus escape the immunity of different members of the human population, a phenomenon that could shape viral evolution and disease susceptibility.

How single mutations affect viral escape from broad and narrow antibodies to H1 influenza hemagglutinin.

Influenza virus can escape most antibodies with single mutations. However, rare antibodies broadly neutralize many viral strains. It is unclear how easily influenza virus might escape such antibodies if there was strong pressure to do so. Here, we map all single amino-acid mutations that increase resistance to broad antibodies to H1 hemagglutinin. Our approach not only identifies antigenic mutations but also quantifies their effect sizes. All antibodies select mutations, but the effect sizes vary widely. The virus can escape a broad antibody to hemagglutinin's receptor-binding site the same way it escapes narrow strain-specific antibodies: via single mutations with huge effects. In contrast, broad antibodies to hemagglutinin's stalk only select mutations with small effects. Therefore, among the antibodies we examine, breadth is an imperfect indicator of the potential for viral escape via single mutations. Antibodies targeting the H1 hemagglutinin stalk are quantifiably harder to escape than the other antibodies tested here.

Auriculasin-induced ROS causes prostate cancer cell death via induction of apoptosis.

Recent studies have demonstrated that natural agents targeting the accumulation of reactive oxygen species (ROS) that selectively kill, leaving normal cells undamaged, can suppress prostate cancer. Here, we show that auriculasin, derived from Flemingia philippinensis, induces significant cell death and apoptosis via ROS generation in prostate cancer cells. Auriculasin treatment resulted in selective apoptotic cell death in LNCaP prostate cancer cells, characterized by DNA fragmentation, accumulation of sub-G1 cell population, cleavage of poly (ADP-ribose) polymerase (PARP), regulation of Bax/Bcl-2 ratio, increase of cytosolic apoptosis-inducing factor (AIF) and endonuclease G (EndoG), in addition to inhibiting tumor growth in a xenograft mouse model. Interestingly, auriculasin-induced apoptosis did not result in caspase-3, -8, and -9 activations. We found that auriculasin treatment decreased phosphorylation of AKT/mTOR/p70s6k in a dose- and time-dependent manner. Further, cellular ROS levels increased in LNCaP cells treated with auriculasin and blocking ROS accumulation with ROS scavengers resulted in inhibition of auriculasin-induced PARP cleavage, AIF increase, upregulation of Bax/Bcl-2 ratio, and decrease in AKT/mTOR phosphorylation. Taken together, these data suggest that auriculasin targets ROS-mediated caspase-independent pathways and suppresses PI3K/AKT/mTOR signaling, which leads to apoptosis and decreased tumor growth.

Generation of polychromatic projection for dedicated breast computed tomography simulation using anthropomorphic numerical phantom.

Numerical simulations are fundamental to the development of medical imaging systems because they can save time and effort in research and development. In this study, we developed a method of creating the virtual projection images that are necessary to study dedicated breast computed tomography (BCT) systems. Anthropomorphic software breast phantoms of the conventional compression type were synthesized and redesigned to meet the requirements of dedicated BCT systems. The internal structure of the breast was randomly constructed to develop the proposed phantom, enabling the internal structure of a naturally distributed real breast to be simulated. When using the existing monochromatic photon incidence assumption for projection-image generation, it is not possible to simulate various artifacts caused by the X-ray spectrum, such as the beam hardening effect. Consequently, the system performance could be overestimated. Therefore, we considered the polychromatic spectrum in the projection image generation process and verified the results. The proposed method is expected to be useful for the development and optimization of BCT systems.