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Background: Perianeurysmal cyst formation after endovascular treatment of cerebral aneurysms is a rare complication; however, the number of reports has gradually increased in recent years due to the development of several endovascular treatments. Case Description: We present a case of delayed perianeurysmal cyst enlargement 8 years after endovascular treatment for multiple recurrences of a large cerebral aneurysm in the anterior communicating artery. The patient presented with obstructive hydrocephalus caused by an enlarged perianeurysmal cyst. The patient underwent cyst fenestration using neuroendoscopy and ventriculoperitoneal shunting, recovered from the clinical symptoms, and had a good prognosis. Histopathological findings showed that the cyst wall contained a fibrotic layer under the monoependymal layer with hemosiderosis without evidence of neovascularization or inflammatory cell infiltration. These findings suggest that the origin of the perianeurysmal cyst wall is not the aneurysm itself but the adjacent brain tissue. Conclusion: Perianeurysmal cysts can develop during long-term follow-up, and clinicians should consider surgical treatment, including cyst fenestration, using neuro-endoscopy if the cyst presents with clinical symptoms.
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A prospective multicenter observational study of organ response was conducted in patients with chronic GVHD diagnosed by the NIH criteria. When response was assessed at 12 months (12 M) in 118 patients, 74.6% were classified as responders and 25.4% as non-responders. The skin and oral cavity were the most frequent organs used as the basis for determining overall response. The lungs, liver, and eyes were also used in 20% of patients. Non-response decisions at 12 M were most frequent in the lungs. A significantly higher percentage of responders than non-responders completed systemic treatment (24.3% vs. 3.3%, P = 0.02). Global scoring showed significant changes, with improvement in responders and worsening in non-responders throughout the observation period. Two-year transplant-related mortality, using the 12 M assessment as the landmark, was significantly worse in non-responders (28.5% vs. 2,7%, P = 0.0001), while the 2-year recurrence rate was equivalent (5.4% vs. 4.8%, P = 0.78). Consequently, the 2-year overall survival rate from the 12 M assessment was significantly better in responders than non-responders (95% vs. 65.3%, P = 0.0001). Our data suggests that patients who do not achieve a response within the first year should be candidates for clinical studies on chronic GVHD.
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Physicians, physical therapists, and occupational therapists have traditionally assessed hand motor function in hemiplegic patients but often struggle to evaluate complex hand movements. To address this issue, in 2019, we developed Fahrenheit, a device and algorithm that uses infrared camera image processing to estimate hand paralysis. However, due to Fahrenheit's dependency on specialized equipment, we conceived a simpler solution: developing a smartphone app that integrates MediaPipe. The objective of this study was to measure hand movements in stroke patients using both MediaPipe and Fahrenheit and to assess their criterion-related validity. The analysis revealed moderate-to-high correlations between the two methods. Consistent results were also observed in the peak angle and velocity comparisons across the severity stages. Because Fahrenheit determines finger recovery status based on these measures, it has the potential to transfer this function to MediaPipe. This study highlighted the potential use of MediaPipe in paralysis estimation applications.
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Tibroviruses are novel rhabdoviruses detected in humans, cattle, and arthropods. Four tibroviruses are known to infect humans: Bas-Congo virus (BASV), Ekpoma virus 1 (EKV-1), Ekpoma virus 2, and Mundri virus. However, since none of them has been isolated, their biological properties are largely unknown. We aimed to characterize the human tibrovirus glycoprotein (G), which likely plays a pivotal role in viral tropism and pathogenicity. Human tibrovirus Gs were found to share some primary structures and display 14 conserved cysteine residues, although their overall amino acid homology was low (29%-48%). Multiple potential glycosylation sites were found on the G molecules, and endoglycosidase H- and peptide-N-glycosidase F-sensitive glycosylation was confirmed. AlphaFold-predicted three-dimensional (3D) structures of human tibrovirus Gs were overall similar. Membrane fusion mediated by these tibrovirus Gs was induced by acidic pH. The low pH-induced conformational change that triggers fusion was reversible. Virus-like particles (VLPs) were produced by transient expression of Gs in cultured cells and used to produce mouse antisera. Using vesicular stomatitis Indiana virus pseudotyped with Gs, we found that the antisera to the respective tibrovirus VLPs showed limited cross-neutralizing activity. It was also found that human C-type lectins and T-cell immunoglobulin mucin 1 acted as attachment factors for G-mediated entry into cells. Interestingly, BASV-G showed the highest ability to utilize these molecules. The viruses infected a wide range of cell lines with preferential tropism for human-derived cells whereas the preference of EKV-1 was unique compared with the other human tibroviruses. These findings provide fundamental information to understand the biological properties of the human tibroviruses. IMPORTANCE: Human tibroviruses are poorly characterized emerging rhabdoviruses associated with either asymptomatic infection or severe disease with a case fatality rate as high as 60% in humans. However, the extent and burden of human infection as well as factors behind differences in infection outcomes are largely unknown. In this study, we characterized human tibrovirus glycoproteins, which play a key role in virus-host interactions, mainly focusing on their structural and antigenic differences and cellular tropism. Our results provide critical information for understanding the biological properties of these novel viruses and for developing appropriate preparedness interventions such as diagnostic tools, vaccines, and effective therapies.
Subject(s)
Viral Envelope Proteins , Humans , Animals , Viral Envelope Proteins/metabolism , Viral Envelope Proteins/genetics , Mice , Glycosylation , Virus Internalization , Viral Tropism , Cell Line , Mucin-1/metabolism , HEK293 Cells , Antibodies, Viral/immunology , Amino Acid SequenceABSTRACT
Background: Cannabidiol (CBD) products have increased in popularity in Japan in recent years, particularly among young people. Some CBD products contain tetrahydrocannabinol (THC), the main ingredient of cannabis, and its analogs, which are illegal in Japan and have become a social issue. This report discusses the safety of CBD products. Case Presentation: Five patients with symptoms of CBD ingestion, including nausea, presented to our hospital. Three of the products these patients ingested contained THC. Metabolites of THC were detected in the blood and urine of all three patients, although there were some discrepancies in the urine drug screening test (DS10®). These examination results differed even when the same product was consumed. Conclusion: CBD products are unsafe and may unintentionally contain THC. It is also important to understand that CBD can turn into THC, and the effective time needed to conduct urine drug screening.
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Lassa virus (LASV) is the etiological agent of Lassa fever (LF), a severe hemorrhagic disease with potential for lethal outcomes. Apart from acute symptoms, LF survivors often endure long-term complications, notably hearing loss, which significantly impacts their quality of life and socioeconomic status in endemic regions of West Africa. Classified as a Risk Group 4 agent, LASV poses a substantial public health threat in affected areas. Our laboratory previously developed a novel lethal guinea pig model of LF utilizing the clinical isolate LASV strain LF2384. However, the specific pathogenic factors underlying LF2384 infection in guinea pigs remained elusive. In this study, we aimed to elucidate the differences in the immunological response induced by LF2384 and LF2350, another LASV isolate from a non-lethal LF case within the same outbreak. Through comprehensive immunological gene profiling, we compared the expression kinetics of key genes in guinea pigs infected with LASV LF2384 and LF2350. Our analysis revealed differential expression patterns for several immunological genes, including CD94, CD19-2, CD23, IL-7, and CIITA, during LF2384 and LF2350 infection. Moreover, through the generation of recombinant LASVs, we sought to identify the specific viral genes responsible for the observed pathogenic differences between LF2384 and LF2350. Our investigations pinpointed the L protein as a crucial determinant of pathogenicity in guinea pigs infected with LASV LF2384.
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BACKGROUND AND AIMS: The mitochondrial translocator protein (TSPO, 18 kDa) is pivotal in binding cholesterol and facilitating its transfer from the outer to the inner mitochondrial membrane. Atriol is a TSPO ligand disrupting cholesterol binding by targeting the cholesterol-recognition amino acid consensus domain. Prior research has shown that TSPO deficiency improved metabolic-associated steatohepatitis (MASH). We hypothesized that Atriol may have the potential to alleviate MASH. METHODS AND RESULTS: In vitro cell culture studies revealed that Atriol treatment effectively mitigated MASH by restoring mitochondrial function, inhibiting the NF-κB signaling pathway, and reducing hepatic stellate cell (HSC) activation. SD male rats were fed a GAN diet for 10 months to induce MASH. During the final two weeks of feeding, rats received intraperitoneal Atriol administration daily. Atriol treatment significantly ameliorated MASH by reducing lipid accumulation, diminishing hepatic lobular inflammation and fibrosis, decreasing cell death, and inhibiting excessive bile acid synthesis. Moreover, Atriol restored mitochondrial function in primary hepatocytes isolated from MASH rats. In search of the mechanism(s) governing these effects, we found that Atriol downregulated the proinflammatory chemokine CXCL1 through the NF-κB signaling pathway or via myeloperoxidase (MPO) in HSCs and Kupffer cells. Additionally, in vitro, studies further suggested that CXCL1 treatment induced dysfunctional mitochondria, inflammation, HSCs activation, and macrophage migration, whereas Atriol countered these effects. Finally, the mitigating effects of Atriol on MASH were reproduced by pharmacological inhibition of NF-κB or MPO and neutralization of CXCL1. CONCLUSION: Atriol ameliorates MASH both in vitro and in vivo, demonstrating its potential therapeutic benefits in managing MASH.
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A simple method for measuring the concentration of nano/microplastics (N/MPs) in soil, which is difficult owing to the size of the filter mesh and the resolution of the measuring instrument, was investigated. A spectrophotometer was used for the measurements and polystyrene particles were used as the N/MP samples. When measuring N/MP concentrations in soil suspensions, absorbance was measured at two wavelengths, and the best combination of wavelengths for measurement was extracted because soil particles and leached components interfere with N/MP absorbance. A wavelength combination of 220-260â¯nm and 280-340â¯nm was found to be suitable for a variety of soils. As N/MPs are adsorbed on the surface of soil particles and precipitate with soil particles in suspension, a calibration curve was created between the concentration of N/MPs in the soil suspension and the N/MP content in the soil. The calibration curve showed a linear relationship, allowing for the estimation of the concentration of N/MPs in the soil. Although other N/MP materials, such as polyethylene and polyethylene terephthalate, must also still be considered and tested, this simple method has the potential to measure N/MPs in various types of soil.
Subject(s)
Environmental Monitoring , Microplastics , Soil Pollutants , Soil , Soil/chemistry , Soil Pollutants/analysis , Environmental Monitoring/methods , Microplastics/analysis , Spectrophotometry, Ultraviolet/methods , Calibration , Polystyrenes/chemistry , Nanoparticles/analysis , Nanoparticles/chemistryABSTRACT
The pathogenesis of viral infection is attributed to two folds: intrinsic cell death pathway activation due to the viral cytopathic effect, and immune-mediated extrinsic cellular injuries. The immune system, encompassing both innate and adaptive immunity, therefore acts as a double-edged sword in viral infection. Insufficient potency permits pathogens to establish lifelong persistent infection and its consequences, while excessive activation leads to organ damage beyond its mission to control viral pathogens. The innate immune response serves as the front line of defense against viral infection, which is triggered through the recognition of viral products, referred to as pathogen-associated molecular patterns (PAMPs), by host cell pattern recognition receptors (PRRs). The PRRs-PAMPs interaction results in the induction of interferon-stimulated genes (ISGs) in infected cells, as well as the secretion of interferons (IFNs), to establish a tissue-wide antiviral state in an autocrine and paracrine manner. Cumulative evidence suggests significant variability in the expression patterns of PRRs, the induction potency of ISGs and IFNs, and the IFN response across different cell types and species. Hence, in our understanding of viral hepatitis pathogenesis, insights gained through hepatoma cell lines or murine-based experimental systems are uncertain in precisely recapitulating the innate antiviral response of genuine human hepatocytes. Accordingly, this review article aims to extract and summarize evidence made possible with bona fide human hepatocytes-based study tools, along with their clinical relevance and implications, as well as to identify the remaining gaps in knowledge for future investigations.
Subject(s)
Hepatitis Delta Virus , Hepatocytes , Immunity, Innate , Interferons , Receptors, Pattern Recognition , Humans , Hepatitis D/immunology , Hepatitis D/virology , Hepatitis Delta Virus/immunology , Hepatitis Delta Virus/physiology , Hepatocytes/virology , Hepatocytes/immunology , Host-Pathogen Interactions/immunology , Interferons/immunology , Interferons/metabolism , Pathogen-Associated Molecular Pattern Molecules/immunology , Receptors, Pattern Recognition/metabolism , Receptors, Pattern Recognition/immunologyABSTRACT
BACKGROUND: Indocyanine green fluorescence angiography, a validated noninvasive imaging technique, is used to assess tissue vascularization. Here, we report three infant patients who underwent intraoperative indocyanine green fluorescence angiography and suffered from postoperative complications caused by the lack of weak fluorescent intestinal resection and assessed residual intestinal perfusion. CASE PRESENTATION: We observed the clinical characteristics and operative findings of patients treated from January 2022 to December 2022. Indocyanine green (0.5 mg/kg) was intravenously injected. The first patient was a 29-day-old girl with surgical necrotizing enterocolitis who underwent intraoperative indocyanine green fluorescence angiography at the first- and second-look operations. The proximal jejunum was difficult to diagnose to detect blood flow during the second-look operation. The second patient was a 32-day-old boy with surgical necrotizing enterocolitis. A part of the antimesenteric mucosa of the patient that exhibited weak fluorescence was preserved; however, it formed postoperative hematomas. The third patient was a 30-day-old boy with midgut volvulus. Weak fluorescence in the intestinal wall was observed 5 cm of the small intestine from the ileocecal valve was preserved, but it formed a stricture, and the patient underwent ileocecal resection after 30 days. CONCLUSIONS: Weak fluorescence in the intestine in infants by performing indocyanine green fluorescence angiography is associated with a high risk of non-recovering ischemic lesions and postoperative complications.
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Dextromethorphan (DXM) is used to treat colds and coughs; however, it can cause central nervous system symptoms, such as severe serotonin syndrome (SS). To our knowledge, there is no specific treatment for severe DXM poisoning, and there are no reports on the clinical use of intravenous lipid emulsion (ILE) for its treatment. Herein, we report a case of severe DXM poisoning with SS that was successfully treated with ILE. An older adolescent male visited the emergency department 1 h after ingesting 4500 mg of DXM orally. Physical examination revealed generalized convulsions, muscle rigidity, mydriasis (8.0/8.0 mm), and flushed skin, with a Glasgow Coma Scale score of 8 (E3V1M4). Severe DXM poisoning with SS was diagnosed. The patient was intubated and administered midazolam for continuous convulsions and SS. Activated charcoal was also administered, and body surface cooling was performed. After an 11 h intensive care unit admission, SS with mydriasis (6.0/6.0 mm) did not improve. Subsequently, 1100 mL of 20% soybean oil was injected as an ILE. Mydriasis improved (3.5/3.5 mm) 30 min after ILE administration; simultaneously, blood DXM concentration rapidly increased approximately two-fold. After discontinuing midazolam, the patient's consciousness signs improved, and he was weaned off the ventilator. SS was cured with no recurrence of convulsions. In cases of DXM poisoning with severe central nervous system disorders, such as SS, ILE treatment can potentially be an effective therapeutic option. For oral overdose cases, where the drug may remain in the intestinal tract, measures such as administering activated charcoal should be taken before administering ILE.
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PURPOSE: The study compares the surgical outcomes of very-early-onset ulcerative colitis (VEO-UC), which is a rare disease diagnosed in pediatric patients < 6 years, with those of older pediatric patients with ulcerative colitis (UC). METHODS: A retrospective observational study of 57 pediatric patients with UC was conducted at a single center. The study compared surgical complications and postoperative growth between the two groups. RESULTS: Out of the 57 patients, 6 had VEO-UC, and 5 of them underwent total colectomy. Compared with the surgical cases of older patients with UC (n = 6), the rate of postoperative complications in patients with VEO-UC (n = 5) was not significantly different, except for high-output ileostomy (80% vs. 0% at 3 weeks postoperatively, p = 0.02). The rate of postoperative central venous catheter (CVC) placement at > 90 days was higher in patients with VEO-UC (100% vs. 17%, p = 0.02). The median change in the Z-score of height before and 2 years after colectomy was not significantly different between VEO-UC and older patients (1.1 vs. 0.3, p = 0.13). CONCLUSION: With regard to complications and outcomes, total colectomy for VEO-UC patients and that for older pediatric UC patients is comparable. However, high-output ileostomy and the long duration of CVC placement may pose management challenges.
Subject(s)
Central Venous Catheters , Colitis, Ulcerative , Child , Humans , Colitis, Ulcerative/surgery , Postoperative Complications/epidemiology , Retrospective Studies , Treatment Outcome , Child, Preschool , Infant , AdolescentABSTRACT
BACKGROUND: Bas-Congo virus (BASV), an emerging tibrovirus, was associated with an outbreak of acute haemorrhagic fever in Mangala, Democratic Republic of the Congo, in 2009. In 2012, neutralising antibodies to BASV were detected in the lone survivor and one of his close contacts. However, subsequent serological and molecular surveys were unsuccessful as neither BASV antibodies nor its RNA were detected. In this study, we determined the seroprevalence of BASV infection in Mangala 13 years after the initial outbreak. METHODS: We conducted a population-based serological survey from Jan 17 to Jan 23, 2022. Consenting individuals at least 5 years of age, living in Mangala for at least 4 weeks, and who had no contraindication to venepuncture were enrolled. Participants were interviewed using a pre-tested questionnaire for sociodemographic and clinical characteristics. We supplemented the collected serum samples with 284 archived samples from Matadi and Kinshasa. All samples were tested for antibodies to BASV and other tibroviruses using a pseudovirus-based neutralisation test. FINDINGS: Among the 267 individuals from Mangala, the prevalence of BASV antibodies was 55% (95% CI 49-61; n=147). BASV seropositivity odds significantly increased with age (5·2 [95% CI 2·1-12·9] to 83·9 [20·8-337·7] times higher in participants aged 20 years or older than participants aged 5-19 years). Some occupational categories (eg, farmer or public servant) were associated with seropositivity. Only nine (6%) of 160 samples from Matadi and one (<1%) of 124 samples from Kinshasa had neutralising antibodies to BASV. Moreover, we also detected neutralising antibodies to other tibroviruses-Ekpoma virus 1, Ekpoma virus 2, and Mundri virus-in 84 (31%), 251 (94%), and 219 (82%) of 267 Mangala samples; 14 (9%), 62 (39%), and 120 (75%) of 160 Matadi samples; and six (5%), five (4%), and 33 (27%) of 124 Kinshasa samples, respectively. INTERPRETATION: Human infection with BASV and other tibroviruses seems common in Mangala, although no deadly outbreak has been reported since 2009. Exposure to BASV might be highly restricted to Mangala and the increasing prevalence of neutralising antibodies with age suggests regular contact with the virus in this city. Altogether, our findings suggest that human infection with tibroviruses could be common in the study areas and not associated with deadly haemorrhagic or debilitating syndromes. FUNDING: Japan Agency for Medical Research and Development (AMED) and Japan International Cooperation Agency (JICA) under the Science and Technology Research Partnership for Sustainable Development (SATREPS) and Japan Program for Infectious Diseases Research and Infrastructure from AMED.
Subject(s)
Antibodies, Viral , Humans , Democratic Republic of the Congo/epidemiology , Male , Seroepidemiologic Studies , Adult , Cross-Sectional Studies , Adolescent , Female , Middle Aged , Child , Young Adult , Antibodies, Viral/blood , Child, Preschool , Antibodies, Neutralizing/blood , Aged , Disease OutbreaksABSTRACT
Introduction and importance: In endovascular treatment of ruptured pseudoaneurysm after pancreaticoduodenectomy (PD) with gastrointestinal bleeding, treatment for vasospasm of the culprit vessel from haemorrhagic shock and subsequent reperfusion has not been determined before. Case presentation: The authors hereby present you with a case of a 59-year-old man with unknown operative method upon arrival at the Emergecy room and who had hematemesis and collapse 6 months post-PD surgery. Clinical discussion: An initial contrast-enhanced computed tomography (CT) revealed no obvious source of bleeding, so an upper gastrointestinal endoscope was performed. Rebleeding occurred during the examination, and interventional radiology was performed because haemostasis was difficult. Coil embolization was performed for leakage of contrast material from the gastroduodenal artery stump into the gastrointestinal tract. However, because the embolization was uncertain due to vasospasm of the common hepatic artery, endoscopic clipping of the perforation site was also performed to prevent rebleeding due to reperfusion after improvement of vasospasm. A CT scan 5 days later showed reperfusion of the coil-implanted vessel. No rebleeding or hepatic infarction occurred postoperatively. Conclusion: In this case, the haemostasis by coil embolization was uncertain due to the presence of vasospasm, and clipping was used in combination with the procedure to prevent rebleeding.
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Guanarito virus (GTOV) is the causative agent of Venezuelan hemorrhagic fever. GTOV belongs to the genus Mammarenavirus, family Arenaviridae and has been classified as a Category A bioterrorism agent by the United States Centers for Disease Control and Prevention. Despite being a high-priority agent, vaccines and drugs against Venezuelan hemorrhagic fever are not available. GTOV S-26764, isolated from a non-fatal human case, produces an unclear cytopathic effect (CPE) in Vero cells, posing a significant obstacle to research and countermeasure development efforts. Vero cell-adapted GTOV S-26764 generated in this study produced clear CPE and demonstrated rapid growth and high yield in Vero cells compared to the original GTOV S-26764. We developed a reverse genetics system for GTOV to study amino acid changes acquired through Vero cell adaptation and leading to virus phenotype changes. The results demonstrated that E1497K in the L protein was responsible for the production of clear plaques as well as enhanced viral RNA replication and transcription efficiency. Vero cell-adapted GTOV S-26764, capable of generating CPE, will allow researchers to easily perform neutralization assays and anti-drug screening against GTOV. Moreover, the developed reverse genetics system will accelerate vaccine and antiviral drug development.IMPORTANCEGuanarito virus (GTOV) is a rodent-borne virus. GTOV causes fever, prostration, headache, arthralgia, cough, sore throat, nausea, vomiting, diarrhea, epistaxis, bleeding gums, menorrhagia, and melena in humans. The lethality rate is 23.1% or higher. Vero cell-adapted GTOV S-26764 shows a clear cytopathic effect (CPE), whereas the parental virus shows unclear CPE in Vero cells. We generated a reverse genetics system to rescue recombinant GTOVs and found that E1497K in the L protein was responsible for the formation of clear plaques as well as enhanced viral RNA replication and transcription efficiency. This reverse genetic system will accelerate vaccine and antiviral drug developments, and the findings of this study contribute to the understanding of the function of GTOV L as an RNA polymerase.
Subject(s)
Arenaviridae , Reverse Genetics , Animals , Female , Humans , Arenaviridae/genetics , Arenaviridae Infections/virology , Arenaviruses, New World/genetics , Chlorocebus aethiops , Hemorrhagic Fevers, Viral/virology , Phenotype , Reverse Genetics/methods , Vaccines , Vero CellsABSTRACT
Post-transplantation therapy is commonly performed in patients with myeloma and can prolong progression-free survival (PFS). However, whether post-transplantation therapy contributes to achieving and continuing MRD-negativity remains controversial. This retrospective analysis aimed to evaluate the clinical impact of post-transplantation therapy, including tandem autologous stem cell transplantation (ASCT), in myeloma patients. The subjects were 79 patients (median age: 62 years) who received induction therapy, including bortezomib and/or lenalidomide, of whom 58 underwent post-transplantation therapy. At the median follow-up time of 50 months, the 4-year PFS rate was significantly higher in patients who underwent post-transplantation therapy than those who did not (60.6% vs. 28.6%, P = 0.012). Multivariate analysis revealed post-transplantation therapy to be a significant prognostic factor for long PFS. Tandem ASCT followed by consolidation and/or maintenance therapies improved PFS and OS. The minimal residual disease (MRD)-negative rate was significantly higher in patients who underwent post-transplantation therapy than those who did not (50.9% vs. 16.7%, P = 0.006). Post-transplantation therapy contributed to sustained MRD-negativity, which predicted long PFS and overall survival. Patients frequently discontinued post-transplantation therapy due to adverse events within 4 months. In conclusion, post-transplantation therapy improved PFS and contributed to sustained MRD-negativity in myeloma patients.
Subject(s)
Hematopoietic Stem Cell Transplantation , Multiple Myeloma , Humans , Middle Aged , Multiple Myeloma/drug therapy , Hematopoietic Stem Cell Transplantation/adverse effects , Treatment Outcome , Retrospective Studies , Transplantation, Autologous , Neoplasm, Residual/drug therapy , Antineoplastic Combined Chemotherapy Protocols/adverse effectsABSTRACT
Clustered DNA damage (cluster) or a multiply damaged site, which is a region with two or more lesions within one or two helical turns, has a high mutagenic potential and causes cell death. We quantified fluorophore-labeled lesions and estimated their proximity through fluorescence anisotropy measurements depending on Förster resonance energy transfer (FRET) among the fluorophores close to each other. pUC19 plasmid DNA (2,686 base pairs) dissolved in water or 0.2 M Tris-HCl buffer at a concentration of 10 µg/µL was irradiated by several ionizing radiations with varying linear energy transfers (LET, 0.2-1890 keV/µm). Electrophilic carbonyls (aldehydes and ketones) at abasic sites (APs) produced in DNA were labeled with Alexa Fluor 488 fluorescent dyes with an O-amino functional group. Regardless of the presence or absence of the buffer, AP yields (the number of APs/base pair/Gy) tended to decrease with increasing LET, and the ratio of the AP yield (in 0.2 M Tris-HCl/in water) was less than 0.1 in the LET range of 0.2-200 keV/µm. However, in a higher LET range, the ratios were greater than 0.1. At a low dose, fluorescence anisotropy decreased with increasing LET in 0.2 M Tris-HCl, whereas, in water, this LET dependence was almost insignificant. These findings suggest that 1. the damage distribution on a DNA molecule formed by indirect effects (e.g., by hydroxyl radicals) does not depend on radiation quality and 2. greater LET radiation is more likely to produce a cluster and/or to produce a cluster with shorter distances between lesions by direct effects. This FRET-based proximity estimation of DNA lesions will contribute not only to the identification of clusters and their complexity in a whole genome, but also to the study of their repair mechanism by single-molecular level fluorescence microscopy.
Subject(s)
DNA Damage , Radiation, Ionizing , Spectrometry, Fluorescence , DNA/genetics , DNA/radiation effects , Fluorescent Dyes , WaterABSTRACT
Immunotherapy has attracted considerable attention as a therapeutic strategy for cancers including acute myeloid leukemia (AML). In this study, we found that the development of several aggressive subtypes of AML is slower in Rag2-/- mice despite the lack of B and T lymphocytes, even compared to the immunologically normal C57BL/6 mice. Furthermore, an orally active p53-activating drug shows stronger antileukemia effect on AML in Rag2-/- mice than C57BL/6 mice. Intriguingly, Natural Killer (NK) cells in Rag2-/- mice are increased in number, highly express activation markers, and show increased cytotoxicity to leukemia cells in a coculture assay. B2m depletion that triggers missing-self recognition of NK cells impairs the growth of AML cells in vivo. In contrast, NK cell depletion accelerates AML progression in Rag2-/- mice. Interestingly, immunogenicity of AML keeps changing during tumor evolution, showing a trend that the aggressive AMLs generate through serial transplantations are susceptible to NK cell-mediated tumor suppression in Rag2-/- mice. Thus, we show the critical role of NK cells in suppressing the development of certain subtypes of AML using Rag2-/- mice, which lack functional lymphocytes but have hyperactive NK cells.
Subject(s)
Killer Cells, Natural , Leukemia, Myeloid, Acute , Animals , Mice , Mice, Knockout , Mice, Inbred C57BL , Leukemia, Myeloid, Acute/genetics , Leukemia, Myeloid, Acute/pathology , T-Lymphocytes , DNA-Binding Proteins/geneticsABSTRACT
Accumulating evidence suggest that ghrelin plays a role as an antiseptic peptide. The present study aimed to clarify whether the brain may be implicated ghrelins antiseptic action. We examined the effect of brain ghrelin on survival in a novel endotoxemic model achieved by treating rats with lipopolysaccharide (LPS) and colchicine. The observation of survival stopped three days after chemicals injection or at death. Intracisternal ghrelin dose-dependently reduced lethality in the endotoxemic model; meanwhile, neither intraperitoneal injection of ghrelin nor intracisternal des-acyl-ghrelin injection affected the mortality rate. The brain ghrelin-induced lethality reduction was significantly blocked by surgical vagotomy. Moreover, intracisternal injection of a ghrelin receptor antagonist blocked the improved survival achieved by intracisternal ghrelin injection or intravenous 2-deoxy-d-glucose administration. Intracisternal injection of an adenosine A2B receptor agonist reduced the lethality and the ghrelin-induced improvement of survival was blocked by adenosine A2B receptor antagonist. I addition, intracisternal ghrelin significantly blocked the colonic hyperpermeability produced by LPS and colchicine. These results suggest that ghrelin acts centrally to reduce endotoxemic lethality. Accordingly, activation of the vagal pathway and adenosine A2B receptors in the brain may be implicated in the ghrelin-induced increased survival. Since the efferent vagus nerve mediates anti-inflammatory mechanisms, we speculate that the vagal cholinergic anti-inflammatory pathway is implicated in the decreased septic lethality caused by brain ghrelin. (AU)