RNA-based detection of genetically modified plants via current-voltage characteristic measurement.

The widespread adoption of genetically modified (GM) crops has escalated concerns about their safety and ethical implications, underscoring the need for efficient GM crop detection methods. Conventional detection methods, such as polymerase chain reaction, can be costly, lab-bound, and time-consuming. To overcome these challenges, we have developed RapiSense, a cost-effective, portable, and sensitive biosensor platform. This sensor generates a measurable voltage shift (0.1-1 V) in the system's current-voltage characteristics, triggered by an increase in membrane's negative charge upon hybridization of DNA/RNA targets with a specific DNA probe. Probes designed to identify the herbicide resistance gene hygromycin phosphotransferase show a detection range from ∼1 nM to ∼10 µM and can discriminate between complementary, non-specific, and mismatched nucleotide targets. The incorporation of a small membrane sensor to detect fragmented RNA samples substantially improve the platform's sensitivity. In this study, RapiSense has been effectively used to detect specific DNA and fragmented RNA in transgenic variants of Arabidopsis, sweet potato, and rice, showcasing its potential for rapid, on-site GM crop screening.

Prenatal hormone stress triggers embryonic cardiac hypertrophy outcome by ubiquitin-dependent degradation of mitochondrial mitofusin 2.

Prenatal stress has been extensively documented as a contributing factor to adverse cardiac development and function in fetuses and infants. The release of glucocorticoids (GCs), identified as a significant stressor, may be a potential factor inducing cardiac hypertrophy. However, the underlying mechanism remains largely unknown. Herein, we discovered that corticosterone (CORT) overload induced cardiac hypertrophy in embryonic chicks and fetal mice in vivo, as well as enlarged cardiomyocytes in vitro. The impaired mitochondria dynamics were observed in CORT-exposed cardiomyocytes, accompanied by dysfunction in oxidative phosphorylation and ATP production. This phenomenon was found to be linked to decreased mitochondrial fusion protein mitofusin 2 (MFN2). Subsequently, we found that CORT facilitated the ubiquitin-proteasome-system-dependent degradation of MFN2 with an enhanced binding of appoptosin to MFN2, serving as the underlying cause. Collectively, our findings provide a comprehensive understanding of the mechanisms by which exposure to stress hormones induces cardiac hypertrophy in fetuses.

Jejunal Cavernous Hemangioma Mimicking Malignancy With Increased Activity on 18 F-FDG PET/CT.

ABSTRACT: A 50-year-old woman underwent 18 F-FDG PET/CT to evaluate possible abdominal malignancy, which was revealed by CT. The images showed a large cystic-solid lesion with peripherally increased FDG activity in the left mid-abdomen. Histopathology of the excised lesion confirmed a jejunal cavernous hemangioma. We reported a rare case of jejunal cavernous hemangioma with FDG accumulation on PET/CT, mimicking malignancy.

18 F-FDG PET/CT of a Rare Sternal Osteoblastoma in a Man With History of Lymphoma.

ABSTRACT: A 27-year-old man, with a history of non-Hodgkin lymphoma 8 years ago, was admitted due to 9 months of persistent sternal pain. Chest CT revealed a mass in the sternum. 18 F-FDG PET/CT was performed, demonstrating a radioactive accumulation mass in the sternum, accompanied by massive osteogenesis and osteolysis. Histological and immunohistochemical analysis of ultrasound-guided fine-needle aspiration biopsy samples confirmed the diagnosis of aggressive osteoblastoma. We present a rare case of aggressive sternal osteoblastoma, instead of lymphoma recurrence, on 18 F-FDG PET/CT in an adult with history of lymphoma.

Novel Homogeneous Anion Exchange Membranes for Reproducible and Sensitive Nucleic Acid Detection via Current-Voltage Characteristic Measurement.

One-pot synthesis of novel hydrogel-based anion exchange membranes (AEMs), with only a single-phase monomer mixture, was used to eliminate surface heterogeneity and generate reproducible electroconvective microvortices in the over-limiting region of the current-voltage characteristic (CVC) curves. Diallyldimethylammonium chloride (DDA) was used as the main component to provide the cation charge groups, and 2-hydroxyethyl methacrylate (HEMA) and ethylene glycol dimethyl acrylate (EGDMA) were used as the auxiliary structure monomers. The uniform membrane structure allowed reproducible and sensitive DNA detection and quantification, as probe-target surface complexes can gate the ion flux and produce large voltage shifts in the over-limiting region. Suppressed membrane curvature due to controlled swelling is a crucial part to avoid the reduction of depletion region for maintaining the influence of target gene hybridization. Fourier-transform infrared (FTIR) spectroscopy verified the synthesized membrane structure, with a residual vinyl group that allows easy carboxylation via additional photografting reaction. Consequently, a significantly higher DNA probe functionalization efficiency is obtained on the homogeneous AEMs, evidenced by the increasing nitrogen element content and bonding via X-ray photoelectron spectroscopy (XPS). The DDA content was optimized to provide a sufficient coulomb force between AEM and nucleic acid backbone to promote the specific binding efficiency but without high dimensional swelling which might change the surface geometry and restrict the voltage shifting for sensing in the over-limiting region, and the optimal DDA/HEMA ratio was found to be 4/10. The synthesized AEM sensor for recombinant 35S promoter sequence identification exhibited a reproducible calibration standard curve with dynamic range between 30 fM and 1 µM and high selectivity with only 0.01 V shift for 1 µM nontarget oligo.

FDG PET/CT Imaging of Pancreatic Plasmacytoma.

A 56-year-old man underwent F-FDG PET/CT to evaluate possible pancreatic cancer, which was revealed by CT. The images showed a solid lesion with peripherally increased FDG activity in the tail of the pancreas, as well as hypermetabolic lesions in the lumbar spine and rib. Pathological examination following lumbar biopsy demonstrated multiple myeloma. Five months after chemotherapy, follow-up FDG PET/CT showed cystic change in the pancreatic lesion without elevated metabolism.

An aptamer-based, fluorescent and radionuclide dual-modality probe.

Aptamers which are promising and effective molecular probes, can deliver either fluorescent materials or radionuclides to tumors. This study aimed to develop a novel both fluorescent and radionuclide dual-modality probe based on a truncated aptamer and evaluate its stability and binding affinities in vitro. The aptamer JHIT2 with binding specifically to HepG2 cells was previously generated by Cell-SELEX. Using mfold and RNAstructure software to predict the secondary structure folded by a middle random sequence to truncate the primer sequences at both ends of the aptamer JHIT2 to yield the aptamer JHIT2e, with a similar secondary structure to JHIT2 and the same specificity and affinity as JHIT2. Attaching carboxyfluorescein (FAM) readily to the aptamer JHIT2e and then attaching iodine-131 to the FAM moiety which has multiple sites for iodine labeling to develop a novel both fluorescent and radionuclide dual-modality probe, termed 131I-FAM-JHIT2e. Cell uptake and fluorescence imaging assays in vitro confirmed that 131I-FAM-JHIT2e had both FAM fluorescence signal and radio-activity signal and maintained specific binding ability to the human hepatoma cell line HepG2. This work formed a basis for aptamer-based, dual-modality imaging probe that contains both fluorescent and radionuclide tags, which also is potential for theranostics.

DEAD-Box RNA Helicase 42 Plays a Critical Role in Pre-mRNA Splicing under Cold Stress.

Low temperature is an important environmental stress that adversely affects rice (Oryza sativa) growth and productivity. Splicing of pre-mRNA is a crucial posttranscriptional regulatory step in gene expression in plants and is sensitive to temperature. DEAD-box RNA helicases belong to an RNA helicase family involved in the rearrangement of ribonucleoprotein complexes and the modification of RNA structure and are therefore involved in all aspects of RNA metabolism. In this study, we demonstrate that the rate of pre-mRNA splicing is reduced in rice at low temperatures and that the DEAD-box RNA Helicase42 (OsRH42) is necessary to support effective splicing of pre-mRNA during mRNA maturation at low temperatures. OsRH42 expression is tightly coupled to temperature fluctuation, and OsRH42 is localized in the splicing speckles and interacts directly with U2 small nuclear RNA. Retarded pre-mRNA splicing and plant growth defects were exhibited by OsRH42-knockdown transgenic lines at low temperatures, thus indicating that OsRH42 performs an essential role in ensuring accurate pre-mRNA splicing and normal plant growth under low ambient temperature. Unexpectedly, our results show that OsRH42 overexpression significantly disrupts the pre-mRNA splicing pathway, causing retarded plant growth and reducing plant cold tolerance. Combined, these results indicate that accurate control of OsRH42 homeostasis is essential for rice plants to respond to changes in ambient temperature. In addition, our study presents the molecular mechanism of DEAD-box RNA helicase function in pre-mRNA splicing, which is required for adaptation to cold stress in rice.

FDG PET/CT Findings of Unsuspected Pulmonary Epithelioid Angiosarcoma Manifested as a Brain Metastasis.

A 42-year-old man presented paroxysmal sharp pain in the right side of the head. Head CT showed a lesion in the right frontal lobe. MRI of the head suggested the possibility of metastasis. FDG PET/CT showed increased uptake corresponding to lesions in the right frontal lobe of the brain, the left upper lobe of lung, and the left adrenal gland, respectively. Cerebral and pulmonary lesions were both resected. Histopathology confirmed that both lesions are primary epithelioid angiosarcomas.

Abnormal O-GlcNAcylation of Pax3 Occurring from Hyperglycemia-Induced Neural Tube Defects Is Ameliorated by Carnosine But Not Folic Acid in Chicken Embryos.

Neural tube defects (NTDs) are among the most common of the embryonic abnormalities associated with hyperglycemic gestation. In this study, the molecular mechanisms of embryonic neurogenesis influenced by hyperglycemia was investigated using chicken embryo models. High-concentration glucose was administered into chicken eggs and resulted in increased plasma and brain tissue glucose, and suppressed expression of glucose transporters (GLUTs). The rate of NTD positively correlated with hyperglycemia. Furthermore, abnormally increased O-GlcNAcylation, a nutritionally responsive modification, of the key neural tube marker Pax3 protein led to the loss of this protein. This loss was not observed in a folate-deficiency NTD induced by methotrexate. Carnosine, an endogenous dipeptide, showed significant recovery effects on neural tube development. In contrast, folic acid, a well-known periconceptional agent, surprisingly showed relatively minimal effect. Higher expression levels of the Pax3 protein were found in the carnosine-treated groups, while lower expression levels were found in folic acid groups. Furthermore, the abnormal O-GlcNAcylation of the Pax3 protein was restored by carnosine. These results suggest new insights into using endogenous nutrients for the protection of embryonic neurodevelopment affected by diabetes gestation. The abnormal excessive O-GlcNAcylation of Pax3 may be responsible for the neural tube defects associated with hyperglycemia.

A new gestational diabetes mellitus model: hyperglycemia-induced eye malformation via inhibition of Pax6 in the chick embryo.

Gestational diabetes mellitus (GDM) is one of the leading causes of fetal malformations. However, few models have been developed to study the underlying mechanisms of GDM-induced fetal eye malformation. In this study, a high concentration of glucose (0.2 mmol per egg) was injected into the air sac of chick embryos on embryo development day (EDD) 1 to develop a hyperglycemia model. Results showed that 47.3% of embryonic eye malformation happened on EDD 5. In this model, the key genes regulating eye development, Pax6, Six3 and Otx2, were downregulated by hyperglycemia. Among these genes, the expression of Pax6 was the most vulnerable to hyperglycemia, being suppressed by 70%. A reduction in Pax6 gene expression induced eye malformation in chick embryos. However, increased expression of Pax6 in chick embryos could rescue hyperglycemia-induced eye malformation. Hyperglycemia stimulated O-linked N-acetylglucosaminylation, which caused oxidative stress in chick embryos. Pax6 was found to be vulnerable to free radicals, but the antioxidant edaravone could restore Pax6 expression and reverse eye malformation. These results illustrated a successful establishment of a new chick embryo model to study the molecular mechanism of hyperglycemia-induced eye malformation. The suppression of the Pax6 gene is probably mediated by oxidative stress and could be a crucial target for the therapy of GDM-induced embryonic eye malformation.

Proanthocyanidins Prevent High Glucose-Induced Eye Malformation by Restoring Pax6 Expression in Chick Embryo.

Gestational diabetes mellitus (GDM) is one of the leading causes of offspring malformations, in which eye malformation is an important disease. It has raised demand for therapy to improve fetal outcomes. In this study, we used chick embryo to establish a GDM model to study the protective effects of proanthocyanidins on eye development. Chick embryos were exposed to high glucose (0.2 mmol/egg) on embryo development day (EDD) 1. Proanthocyanidins (1 and 10 nmol/egg) were injected into the air sac on EDD 0. Results showed that both dosages of proanthocyanidins could prevent the eye malformation and rescue the high glucose-induced oxidative stress significantly, which the similar effects were showed in edaravone. However, proanthocyanidins could not decrease the glucose concentration of embryo eye. Moreover, the key genes regulating eye development, Pax6, was down-regulated by high glucose. Proanthocyanidins could restore the suppressed expression of Pax6. These results indicated proanthocyanidins might be a promising natural agent to prevent high glucose-induced eye malformation by restoring Pax6 expression.

A natural product, resveratrol, protects against high-glucose-induced developmental damage in chicken embryo.

Resveratrol, a famous plant-derived polyphenolic phytoalexin, has been considered to play physiological roles such as antioxidative, neuroprotective, and anticancer effects in adults. However, its antioxidative activity and neuroprotective effect were seldom discussed in the embryonic system. In this study, the effect of resveratrol on chicken embryo development under high glucose and its underlying mechanism of resveratrol were investigated. High glucose administrated to chicken embryo at embryonic Day 1 induced stillbirth, growth retardation, and impaired blood vessel development on yolk sac. However, resveratrol supplementation before glucose exposure showed significant effect on decreasing the death rate, developmental damage, and vessel injury. In addition, oxidative stress was caused by high-glucose exposure, and resveratrol could rescue this high-glucose-induced oxidative stress. Moreover, the neural developmental marker paired box 3 was significantly decreased by high glucose and recovered by resveratrol. Cell cycle-regulated gene expression was also intervened by resveratrol. This study had found an association between resveratrol and hyperglycemia-induced embryonic damage, which suggested a potential protective effect of resveratrol on gestational diabetes.