Data-Driven Design of Triple-Targeted Protein Nanoprobes for Multiplexed Imaging of Cancer Lymphatic Metastasis.

Targeted imaging of cancer lymphatic metastasis remains challenging due to its highly heterogeneous molecular and phenotypic diversity. Herein, triple-targeted protein nanoprobes capable of specifically binding to three targets for imaging cancer lymphatic metastasis, through a data-driven design approach combined with a synthetic biology-based assembly strategy, are introduced. Specifically, to address the diversity of metastatic lymph nodes (LNs), a combination of three targets, including C-X-C motif chemokine receptor 4 (CXCR4), transferrin receptor protein 1 (TfR1), and vascular endothelial growth factor receptor 3 (VEGFR3) is identified, leveraging machine leaning-based bioinformatics analysis and examination of LN tissues from patients with gastric cancer. Using this identified target combination, ferritin nanocage-based nanoprobes capable of specifically binding to all three targets are designed through the self-assembly of genetically engineered ferritin subunits using a synthetic biology approach. Using these nanoprobes, multiplexed imaging of heterogeneous metastatic LNs is successfully achieved in a polyclonal lymphatic metastasis animal model. In 19 freshly resected human gastric specimens, the signal from the triple-targeted nanoprobes significantly differentiates metastatic LNs from benign LNs. This study not only provides an effective nanoprobe for imaging highly heterogeneous lymphatic metastasis but also proposes a potential strategy for guiding the design of targeted nanomedicines for cancer lymphatic metastasis.

Downregulation of HHATL promotes cardiac hypertrophy via activation of SHH/DRP1.

HHATL, previously implicated in cardiac hypertrophy in the zebrafish model, has emerged as a prioritized HCM risk gene. We identified six rare mutations in HHATL, present in 6.94 % of nonsarcomeric HCM patients (5/72). Moreover, a decrease of HHATL in the heart tissue from HCM patients and cardiac hypertrophy mouse model using transverse aortic constriction was observed. Despite this, the precise pathogenic mechanisms underlying HHATL-associated cardiac hypertrophy remain elusive. In this study, we observed that HHATL downregulation in H9C2 cells resulted in elevated expression of hypertrophic markers and reactive oxygen species (ROS), culminating in cardiac hypertrophy and mitochondrial dysfunction. Notably, the bioactive form of SHH, SHHN, exhibited a significant increase, while the mitochondrial fission protein dynamin-like GTPase (DRP1) decreased upon HHATL depletion. Intervention with the SHH inhibitor RU-SKI 43 or DRP1 overexpression effectively prevented Hhatl-depletion-induced cardiac hypertrophy, mitigating disruptions in mitochondrial morphology and membrane potential through the SHH/DRP1 axis. In summary, our findings suggest that HHATL depletion activates SHH signaling, reducing DRP1 levels and thereby promoting the expression of hypertrophic markers, ROS generation, and mitochondrial dysfunction, ultimately leading to cardiac hypertrophy. This study provides additional compelling evidence supporting the association of HHATL with cardiac hypertrophy.

A review of pulmonary toxicity of different types of quantum dots in environmental and biological systems.

Quantum dots (QDs) are nanoparticles with a particle size of 1-10 nm. Typical QDs are made of compounds such as cadmium sulfide, cadmium selenide, silver sulfide, and indium phosphide, among others. QDs exhibit promising potential for a wide range of applications owing to their excellent optical properties. With the rise in the application of and demand for QDs, QDs accumulation in the environment has increased markedly. QDs enter the pulmonary system via inhalation and trigger pulmonary toxicity. This paper first reviews the pulmonary toxicity of different types of QDs in vivo and in vitro. Regarding acute toxicity, QDs cause changes in cell morphology, cell membrane disruption, cell viability, and pulmonary inflammation. Regarding chronic toxicity, cadmium-based QDs cause pulmonary granulomas and have a potential carcinogenic risk. Second, this paper presents an overview of the pulmonary toxicity mechanism of QDs, involving oxidative stress, inflammation, autophagy, apoptosis, and ferroptosis. It summarizes mitogen-activated protein kinases, nuclear factor κB, nuclear factor-erythroid 2-related factor 2, P53, and Phosphoinositide 3-kinase/AKT signaling pathways in apoptosis and autophagy. Third, it enumerates the physicochemical properties of QDs influencing pulmonary toxicity, ranging from components, surface functional groups, size, and surface charge. Lastly, it outlines the shortcomings of current studies on QDs pulmonary toxicity. The paper concludes with a recommendation discussing research-based improvements in the physicochemical properties of QDs to reduce their release in the environment.

To Investigate Whether Hematocrit Affects Thromboelastography Parameters.

Background: Thromboelastogram (TEG) is an experiment to detect coagulation function with whole blood. Red blood cell (RBC) is the most abundant component of blood. Whether RBC has an impact on the results of thromboelastogram? Study Design and Methods. The correlation between hematocrit (HCT) and TEG was analyzed. 17 samples were reconstituted with different HCT. They were tested separately. Correction tests were performed on 17 samples from patients with anemia. HCT was corrected to 0.40 in female and 0.45 in males. The correction formula was determined according to the experimental correction. Results: HCT was negatively correlated with TEG parameters. As HCT increased, CI and angle decreased (P < 0.05, P < 0.001) and K increased (P < 0.001) in reconstituted samples. In the correction test, the angle measured value was 69.48 ± 4.98 and corrected value was 62.48 ± 6.25, MA measured value was 61.44 ± 7.10 and corrected value was 55.94 ± 7.12, K measured value was 1.45 ± 0.48 and corrected value was 2.11 ± 0.79, and CI measured value was 1.07 ± 1.67 and corrected value was -0.45 ± 1.64. There was a significant difference. The correction formulas of anemia were derived from the experimental correction results. K Correction value = (0.7903∗ A 2 - 2.1803A + 2.8268)∗ K Measured value; Tan angleCorrection value = Tan angleMeasured value/(0.6596∗ A 2 - 1.7478A + 2.4608); MACorrection value = MAMeasured value/(0.1853ln (A) + 1.0197); CICorrection value = -0.6516RMeasured value - 0.3772K Correction value + 0.1224MACorrection value + 0.0759angleCorrection value - 7.7922. Conclusion: HCT has a negative impact on TEG parameters. Coagulation state of anemia patients is overestimated by TEG. The test results of anemia patients need to be corrected whether through the experimental correction or the formula correction.

[Three Novel Blood Group Systems Registered by ISBT in 2019 --Review].

There were three new blood group systems including the KANNO blood group system, the Sid blood group system and the CTL2 blood group system (provisional status), have been registered by the International Society of Blood Transfusion (ISBT) registered Science August 2019. The main reason for this update is that the significant SNPs of the KANNO blood group system (rs1800014) and the Sid blood group system (rs7224888) have been found through genome-wide association studies and whole exome sequencing. The new genetic evidences are consistent with the current immunological findings. In addition, although CTL2 antigen has been found on erythrocyte ghost (erythrocyte membrane) since 2017, CTL2 blood group system is still in provisional status due to lack of serological and genetic evidence. In this review, the experimental research advances of these three ISBT blood group systems and discuss the clinical value of the relevant researches was summarized briefly.

The NLRP3-Mediated Neuroinflammatory Responses to CdTe Quantum Dots and the Protection of ZnS Shell.

INTRODUCTION: Since CdTe quantum dots (QDs) are still widely considered as advanced fluorescent probes because of their far superior optical performance and fluorescence efficiency over non-cadmium QDs, it is important to find ways to control their toxicity. METHODS: In this study, the adverse effects of two cadmium-containing QDs, ie, CdTe QDs and CdTe@ZnS QDs, on the nervous system of nematode C. elegans, the hippocampus of mice, and cultured microglia were measured in order to evaluate the neuroinflammation caused by cadmium-containing QDs and the potential mechanisms. RESULTS: Firstly, we observed that cadmium-containing QD exposure-induced immune responses and neurobehavioral deficit in nematode C. elegans. In the mice treated with QDs, neuroinflammatory responses to QDs in the hippocampus, including microglial activation and IL-1ß release, occurred as well. When investigating the mechanisms of cadmium-containing QDs causing IL-1ß-mediated inflammation, the findings suggested that cadmium-containing QDs activated the NLRP3 inflammasome by causing excessive ROS generation, and resulted in IL-1ß release. DISCUSSION: Even though the milder immune responses and neurotoxicity of CdTe@ZnS QDs compared with CdTe QDs indicated the protective role of ZnS coating, the inhibitions of NLRP3 expression and ROS production completely reduced the IL-1ß-mediated inflammation. This provided valuable information that inhibiting target molecules is an effective and efficient way to alleviate  the toxicity of cadmium-containing QDs, so it is important to evaluate QDs through a mechanism-based risk assessment.

A metabolomics study: CdTe/ZnS quantum dots induce polarization in mice microglia.

In this study, a metabolomic analysis was used to reveal the neurotoxicity of the CdTe/ZnS QDs via microglia polarization. A gas chromatography-mass spectrometer (GC-MS) was applied to uncover the metabonomic changes in microglia (BV-2 cell line) after exposure to 1.25 µM CdTe/ZnS QDs. 11 annotated metabolic pathways (KEGG database) were significantly changed in all exposed groups (3 h, 6 h, 12 h), 3 of them were related to glucose metabolism. The results of the Seahorse XFe96 Analyzer indicated that the CdTe/ZnS QDs increased the glycolysis level of microglia by 86% and inhibited the aerobic respiration level by 54% in a non-hypoxic environment. In vivo study, 3 h after the injection of CdTe/ZnS QDs (2.5 mM) through the tail vein in mice, the concentration of the CdTe/ZnS QDs in hippocampus reached the peak (1.25 µM). The polarization level of microglia (Iba-1 immunofluorescence) increased 2.7 times. In vitro study, the levels of the extracellular TNF-α, IL-1ß and NO of BV-2 cells were all increased significantly after a 6 h or 12 h exposure. According to the results of the Cell Counting Kit-8, after a 6 h or 12 h exposure to the CdTe/ZnS QDs, the exposed microglia could significantly decrease the number of neurons (HT-22 cell line). This study proved that CdTe/ZnS QDs could polarize microglia in the brain and cause secondary inflammatory damage to neurons. There are potential risks in the application of the CdTe/ZnS QDs in brain tissue imaging.

The glycolytic shift was involved in CdTe/ZnS quantum dots inducing microglial activation mediated through the mTOR signaling pathway.

The excellent optical property and relatively low toxicity of CdTe/ZnS core/shell quantum dots (QDs) make them an advanced fluorescent probe in the application of biomedicines, particularly in neuroscience. Thus, it is important to evaluate the biosafety of CdTe/ZnS QDs on the central nervous system (CNS). Our previous studies have suggested that the high possibility of CdTe/ZnS QDs being transported into the brain across the blood-brain barrier resulted in microglial activation and a shift of glycometabolism, but their underlying mechanism remains unclear. In this study, when mice were injected intravenously with CdTe/ZnS QDs through tail veins, the microglial activation, polarized into both M1 phenotype and M2 phenotype, and the neuronal impairment were observed in the hippocampus. Meanwhile, the increased pro- and anti-inflammatory cytokines released from BV2 microglial cells treated with CdTe/ZnS QDs also indicated that QD exposure was capable of inducing microglial activation in vitro. We further demonstrated that the glycolytic shift from oxidative phosphorylation switching into aerobic glycolysis was required in the microglial activation into M1 phenotype induced by CdTe/ZnS QD treatment, which was mediated through the mTOR signaling pathway. The findings, taken together, provide a mechanistic insight regarding the CdTe/ZnS QDs inducing microglial activation and the role of the glycolytic shift in it.

The role of NLRP3 inflammasome activation in the neuroinflammatory responses to Ag2Se quantum dots in microglia.

Silver selenide quantum dots (Ag2Se QDs) provide bright prospects for the application of QDs in the field of biomedicine because they contain low-toxic compounds and show great advantages in the imaging of deep tissues and tiny vascular structures. However, the biosafety of these novel QDs has not been thoroughly evaluated, especially in one main target for toxicity-the central nervous system (CNS). Our previous studies have suggested severe inflammatory responses to cadmium-containing QDs in the hippocampus, which gives us a hint regarding the risk assessment of Ag2Se QDs. In this study, microglial activation followed by enhanced levels of pro-inflammatory cytokines was observed in the hippocampus of mice intravenously injected with Ag2Se QDs. When using the microglial BV2 cells to investigate the underlying mechanisms, we found that the NLRP3 inflammasome activation was involved in the IL-1ß-mediated inflammation induced by Ag2Se QDs. On the one hand, Ag2Se QD-activated NF-κB participated in the NLRP3 inflammasome priming and assembly as well as the pro-IL-1ß upregulation. On the other hand, Ag2Se QD-induced ROS generation, particularly mtROS, triggered the NLRP3 inflammasome activation and resulted in active caspase-1 to process pro-IL-1ß into mature IL-1ß release. These findings not only indicated that it is important to evaluate the biosafety of novel QDs, even those containing low-toxic compounds, but also provided an unbiased and mechanism-based risk assessment of similar nanoparticles.

The apoptosis induced by silica nanoparticle through endoplasmic reticulum stress response in human pulmonary alveolar epithelial cells.

Recently, the use of silica nanoparticles (SiO2-NPs) and mesoporous silica nanoparticles (mSiO2-NPs) in the biomedical field, such as biosensors, drug deliveries and bioactivator carriers, is increasing due to their special physiochemical properties. However, the biosafety assessment of them is far lagging behind their rapid application. In this study, we observed that both SiO2-NPs and mSiO2-NPs with certain exposed doses decreased the cell viability while increased the apoptosis rates in the human pulmonary alveolar epithelial cells (HPAEpiC). Generally, mSiO2-NPs presented less toxic effects than SiO2-NPs with same treated dose, which assures the positive application prospect of mSiO2-NPs in the area of biomedicine. Since both SiO2-NPs could be taken into cells and accumulated in the endoplasmic reticulum (ER), which resulted in pathologically morphological changes and subcellular organelle damages, we hypothesized that the ER stress response could be involved in the NPs-induced apoptosis. The findings suggested that SiO2-NPs and mSiO2-NPs exposure increased the expression levels of two ER stress markers, e.g. BiP and CHOP, which could be inhibited by the ER stress inhibitor 4-PBA, following with decreased apoptosis rates in HPAEpiC. Even though it is still unclear of the direct target of NPs causing ER stress response following with cell apoptosis, our findings provide a novel insight for researchers to explore the toxic mechanisms of SiO2-NPs and mSiO2-NPs in order to reduce the adverse effects of them.

DNA damage in BV-2 cells: An important supplement to the neurotoxicity of CdTe quantum dots.

Microglial cells are resident immune cells in the central nervous system. Activation of microglia as induced by CdTe quantum dots (QDs) can trigger damage to neurons. To quantify the intracellular QDs, we monitored the intracellular Cd concentration in the QD-exposed mouse microglial cells (BV-2 cell line). The extent of cell injury at different times correlated with the Cd concentration in cells at that time. In addition to Cd ion detection, we also monitored the intracellular fluorescence of the QDs. More QDs accumulated in the nucleus than in the cytoplasm. Comet assays confirmed that QDs induce DNA damage. However, DNA cannot interact with QDs, so the DNA damage was not caused by CdTe QDs adducts to DNA but by the increase of the Cd ion concentration and the secondary oxidative damage. In addition to DNA damage, biofilm injury and endogenous reduced glutathione depletion were also apparent in QD-exposed BV-2 cells. These changes can be prevented or even reversed by exogenous reduced glutathione administration.

MPA-modified CdTe quantum dots increased interleukin-1beta secretion through MyD88-dependent Toll-like receptor pathway and NLRP3 inflammasome activation in microglia.

The excellent optical properties of CdTe quantum dots (QDs) make researchers realize their value on the application of biomedicine, especially neuroscience, as an advanced fluorescent probe. Thus, it is important to evaluate the biosafety of CdTe QDs on the central nervous system (CNS). Our previous studies have conducted a systematic biosafety evaluation of CdTe QDs on the CNS and found several toxic endpoints, one of which is the inflammation on the rat hippocampus, but their underlying mechanism remains unclear. In this study, when BV2 microglial cells were exposed to CdTe QDs with doses <20 nM, there was no obviously adverse effect. However, 40 nM CdTe QDs exposure could significantly activate the BV2 cells and increase the pro-inflammatory cytokine IL-1ß secretion. Molecular biology analyses suggested that both TLR2/MyD88/NF-κB pathway and NLRP3 inflammasome participated in the CdTe QD-induced IL-1ß secretion. The former served as the first signal for pro-IL-1ß expression, while the later played a role on the maturation of pro-IL-1ß into IL-1ß. The results, taken together, demonstrated that MPA-modified CdTe QDs exposure with a high concentration was capable of activating microglial cells and promoting IL-1ß secretion, which was highly correlated with the activations of both TLR2/MyD88/NF-κB pathway and ROS-induced NLRP3 inflammasome. These findings provide some mechanistic insights regarding the neuroinflammatory responses to cadmium-based QDs.

Transcriptome analysis of different sizes of 3-mercaptopropionic acid-modified cadmium telluride quantum dot-induced toxic effects reveals immune response in rat hippocampus.

Recently, the increasing number of bio-safety assessments on cadmium-containing quantum dots (QDs) suggested that they could lead to detrimental effects on the central nervous system (CNS) of living organisms, but the underlying action mechanisms are still rarely reported. In this study, whole-transcriptome sequencing was performed to analyze the changes in genome-wide gene expression pattern of rat hippocampus after treatments of cadmium telluride (CdTe) QDs with two sizes to understand better the mechanisms of CdTe QDs causing toxic effects in the CNS. We identified 2095 differentially expressed genes (DEGs). Fifty-five DEGs were between the control and 2.2 nm CdTe QDs, 1180 were between the control and 3.5 nm CdTe QDs and 860 were between the two kinds of CdTe QDs. It seemed that the 3.5 nm CdTe QD exposure might elicit severe effects in the rat hippocampus than 2.2 nm CdTe QDs at the transcriptome level. After bioinformatics analysis, we found that most DEG-enriched Gene Ontology subcategories and Kyoto Encyclopedia of Genes and Genomes pathways were related with the immune system process. For example, the Gene Ontology subcategories included immune response, inflammatory response and T-cell proliferation; Kyoto Encyclopedia of Genes and Genomes pathways included NOD/Toll-like receptor signaling pathway, nuclear factor-κB signaling pathway, tumor necrosis factor signaling pathway, natural killer cell-mediated cytotoxicity and T/B-cell receptor signaling pathway. The traditional toxicological examinations confirmed the systemic immune response and CNS inflammation in rats exposed to CdTe QDs. This transcriptome analysis not only revealed the probably molecular mechanisms of CdTe QDs causing neurotoxicity, but also provided references for the further related studies.

Safety of novel liposomal drugs for cancer treatment: Advances and prospects.

Liposome is a kind of prospective abiotic drug delivery system for cancer treatment. Novel liposomes modified with PEG, cationic lipids and highly selective molecules achieve better stability, half-life and selectivity as well as less severe side effects. However, novel liposomes are still not nontoxic. PEG on the surface of liposomes interfere the combination of cancer cells and drugs. Cationic liposomes can induce oxidative damage and cytotoxicity to normal tissues. To further improve the safety of liposomal drugs, liposomal drugs must be highly selective to cancer tissues and cancer cells, at the same time, induce minimum damage to normal cells. It is necessary to gather several advantages of novel liposomes. The ideal targeted drug delivery system is like a multistage rocket. Firstly, the liposomal drugs should be sensitive to the specific environment of cancer tissues and accumulate in there. Secondly, the liposomes could selectively combine with cancer cells by surface modification. Lastly, in cancer cells, drugs release from the carriers rapidly. What's more, form the records of clinical researches, the side effects induced by liposomal drugs, such as acute infusion reaction and hand-foot syndrome(HFS), are also unignorable. More attention should be paid to these safety problems in new liposomal drugs research and development.

The protective effects of resveratrol, H2S and thermotherapy on the cell apoptosis induced by CdTe quantum dots.

Quantum dots (QDs) could be used in the field of biology and medicine as excellent nano-scale fluorescent probes due to their unique optical properties, but the adverse effects of QDs are always the obstruction for its usage in living organisms. In this study, we observed that CdTe QDs exposure decreased the cell viability while increased the apoptosis rates in the L929 cells. Apart from QD-induced oxidative stress indicated by excessive ROS generation, three signal transductions, including Akt, p38 and JNK, played important roles on the regulation of cell apoptosis by CdTe QDs exposure as well. In order to reduce the toxicity of CdTe QDs, we explored the protective effects of three treatments, i.e. resveratrol, H2S and thermotherapy at 43°C, against the cell apoptosis elicited by CdTe QDs. The results showed that resveratrol, H2S and thermotherapy at 43°C were capable of attenuating cell apoptosis and intercellular ROS production through inhibiting signal pathways of Akt, p38 and JNK, respectively. As there is only limited number of exogenous treatments reported to diminish the toxicity of QDs, our findings will provide a novel insight for researchers who try to reduce or even eliminate the adverse health effects of QDs.

Impairments of spatial learning and memory following intrahippocampal injection in rats of 3-mercaptopropionic acid-modified CdTe quantum dots and molecular mechanisms.

With the rapid development of nanotechnology, quantum dots (QDs) as advanced nanotechnology products have been widely used in neuroscience, including basic neurological studies and diagnosis or therapy for neurological disorders, due to their superior optical properties. In recent years, there has been intense concern regarding the toxicity of QDs, with a growing number of studies. However, knowledge of neurotoxic consequences of QDs applied in living organisms is lagging behind their development, even if several studies have attempted to evaluate the toxicity of QDs on neural cells. The aim of this study was to evaluate the adverse effects of intrahippocampal injection in rats of 3-mercaptopropionic acid (MPA)-modified CdTe QDs and underlying mechanisms. First of all, we observed impairments in learning efficiency and spatial memory in the MPA-modified CdTe QD-treated rats by using open-field and Y-maze tests, which could be attributed to pathological changes and disruption of ultrastructure of neurons and synapses in the hippocampus. In order to find the mechanisms causing these effects, transcriptome sequencing (RNA-seq), an advanced technology, was used to gain the potentially molecular targets of MPA-modified CdTe QDs. According to ample data from RNA-seq, we chose the signaling pathways of PI3K-Akt and MPAK-ERK to do a thorough investigation, because they play important roles in synaptic plasticity, long-term potentiation, and spatial memory. The data demonstrated that phosphorylated Akt (p-Akt), p-ERK1/2, and c-FOS signal transductions in the hippocampus of rats were involved in the mechanism underlying spatial learning and memory impairments caused by 3.5 nm MPA-modified CdTe QDs.

MPA-capped CdTe quantum dots exposure causes neurotoxic effects in nematode Caenorhabditis elegans by affecting the transporters and receptors of glutamate, serotonin and dopamine at the genetic level, or by increasing ROS, or both.

As quantum dots (QDs) are widely used in biomedical applications, the number of studies focusing on their biological properties is increasing. While several studies have attempted to evaluate the toxicity of QDs towards neural cells, the in vivo toxic effects on the nervous system and the molecular mechanisms are unclear. The aim of the present study was to investigate the neurotoxic effects and the underlying mechanisms of water-soluble cadmium telluride (CdTe) QDs capped with 3-mercaptopropionic acid (MPA) in Caenorhabditis elegans (C. elegans). Our results showed that exposure to MPA-capped CdTe QDs induced behavioral defects, including alterations to body bending, head thrashing, pharyngeal pumping and defecation intervals, as well as impaired learning and memory behavior plasticity, based on chemotaxis or thermotaxis, in a dose-, time- and size-dependent manner. Further investigations suggested that MPA-capped CdTe QDs exposure inhibited the transporters and receptors of glutamate, serotonin and dopamine in C. elegans at the genetic level within 24 h, while opposite results were observed after 72 h. Additionally, excessive reactive oxygen species (ROS) generation was observed in the CdTe QD-treated worms, which confirmed the common nanotoxicity mechanism of oxidative stress damage, and might overcome the increased gene expression of neurotransmitter transporters and receptors in C. elegans induced by long-term QD exposure, resulting in more severe behavioral impairments.

qPCR-DAMS: a database tool to analyze, manage, and store both relative and absolute quantitative real-time PCR data.

Quantitative real-time PCR is an important high-throughput method in the biomedical sciences. However, existing software has limitations in handling both relative and absolute quantification. We designed quantitative PCR data analysis and management system (qPCR-DAMS), a database tool based on Access 2003, to deal with such shortcomings by the addition of integrated mathematical procedures. qPCR-DAMS allows a user to choose among four methods for data processing within a single software package: 1) ratio relative quantification, 2) absolute level, 3) normalized absolute expression, and 4) ratio absolute quantification. qPCR-DAMS also provides a tool for multiple reference gene normalization. qPCR-DAMS has three quality control steps and a data display system to monitor data variation. In summary, qPCR-DAMS is a handy tool for real-time PCR users.