Acid-Triggered Degradation of Three-In-One Ag2S Quantum Dots for In Situ Ratiometric NIR-II Fluorescence Imaging-Guided Ion/Gas Combination Therapy.

Smart theranostic nanoprobes with the integration of multiple therapeutic modalities are preferred for precise diagnosis and efficient therapy of tumors. However, it remains a big challenge to arrange the imaging and two or more kinds of therapeutic agents without weakening the intended performances. In addition, most existing fluorescence (FL) imaging agents suffer from low spatiotemporal resolution due to the short emission wavelength (<900 nm). Here, novel three-in-one Ag2S quantum dot (QD)-based smart theranostic nanoprobes were proposed for in situ ratiometric NIR-II FL imaging-guided ion/gas combination therapy of tumors. Under the acidic tumor microenvironment, three-in-one Ag2S QDs underwent destructive degradation, generating toxic Ag+ and H2S. Meanwhile, their FL emission at 1270 nm was weakened. Upon introduction of a downconversion nanoparticle (DCNP) as the delivery carrier and NIR-II FL reference signal unit, the formed Ag2S QD-based theranostic nanoprobes could achieve precise diagnosis of tumors through ratiometric NIR-II FL signals. Also, the generated Ag+ and H2S enabled specific ion/gas combination therapy toward tumors. By combining the imaging and therapeutic functions, three-in-one Ag2S QDs may open a simple yet reliable avenue to design theranostic nanoprobes.

Fluidic Membrane Accelerating the Kinetics of Photoactivatable Hybridization Chain Reaction for Accurate Imaging of Tumor-Derived Exosomes.

Slow intermolecular collisions and "always active" responses compromise the amplification efficiency and response accuracy of nonenzymatic hybridization chain reaction (HCR). In this study, a photoactivatable membrane-oriented HCR (MOHCR) system was rationally designed by binding a photocleavable initiator probe onto a target protein and then anchoring cholesterol-modified hairpin-structure fuel probes. When irradiated, the bound initiator probe was photoactivated and initiated self-assembly to generate activatable and amplified imaging. In a proof-of-concept assay, breast-cancer-derived exosomes were imaged based on the surface protein epithelial cell adhesion molecule (EpCAM). Photoactivatable responses provided precise spatiotemporal control of the MOHCR, and fluidic membranes enabled accelerated reaction kinetics. Our MOHCR system demonstrated high efficiency and accuracy in differentiating between plasma samples from breast cancer patients and healthy donors.

MicroRNA-29a inhibits collagen expression and induces apoptosis in human fetal scleral fibroblasts by targeting the Hsp47/Smad3 signaling pathway.

Members of the microRNA-29 (miR-29) gene family have been implicated as suppressors of collagen in several human diseases. The present study aimed to explore the function of miR-29a in human fetal scleral fibroblasts (HFSFs) and to investigate potential mechanisms by which the molecule regulates cellular functioning. First, HFSFs were transfected with miR-29a mimic, miR-29a inhibitor, or their corresponding controls. Then, cell proliferation and apoptosis were assessed using a CCK-8 assay and flow cytometry, respectively. Further, using real-time PCR, western blotting, and immunofluorescence staining, levels of miR-29a, heat shock protein 47 (Hsp47), COL1A1, Smad3, P-Smad3, Bax, and Bcl-2 were investigated. Next, empty vectors and SERPINH1-overexpressing vectors were used to transfect HFSFs. Western blotting and flow cytometry were performed to assess changes in levels of HFSF protein expression and apoptosis, respectively. Results indicated that the miR-29a mimic significantly inhibited Hsp47, Smad3, P-Smad3, and COL1A1 expression. Conversely, the miR-29a inhibitor enhanced the expression of the same genes. Furthermore, miR-29a overexpression inhibited HFSFs proliferation and enhanced the rate of HFSFs apoptosis. Consistent with this finding, miR-29a overexpression led to the downregulation of Bcl-2 and upregulation of Bax. In contrast, miR-29a suppression led to the upregulation of Bcl-2 and downregulation of Bax expression and reduced the rate of apoptosis. Additional research revealed that overexpression of Hsp47 prevented HFSFs apoptosis and enhanced collagen production. Findings that miR-29a overexpression reduces collagen expression levels, slows proliferation, and promotes apoptosis in HFSFs highlight the key role of miR-29a in scleral remodeling. The effects of miR-29a on scleral remodeling might mediate by targeting Hsp47 and repressing the Smad3 pathway.

Role of haematopoietic cell-specific protein 1-associated protein X-1 gene in lipopolysaccharide-induced apoptosis of human dermal fibroblasts.

Wound healing may be disrupted by lipopolysaccharide (LPS)-induced mitochondrial dysfunction, inflammation, and excessive oxidative stress, which can lead to undesirable consequences. The haematopoietic cell-specific protein 1-associated protein X-1 (HAX-1) is a mitochondrial matrix protein that regulates mitochondrial function. This study aimed to comprehensively identify the role of HAX-1 in the inhibition of LPS-induced mitochondrial dysfunction and apoptosis in human dermal fibroblasts (HDFs). HAX-1 expression was assessed in the HDF-a cell line using real-time polymerase chain reaction, western blotting, and immunohistochemical staining. The viability, migration, and apoptosis of HDF-a cells were evaluated using the water-soluble tetrazolium-1 assay, transwell assay, and flow cytometry analysis, respectively. Mitochondrial function was evaluated based on reactive oxygen species (ROS) generation and mitochondrial membrane potential (ΔΨm). Our results demonstrated that LPS stimulation markedly repressed HAX-1 expression in HDFs and silencing of HAX-1 led to mitochondrial ROS accumulation, ΔΨm disruption, and abnormal mitochondrial morphology. Accordingly, overexpression of HAX-1 or administration of metformin enhanced mitochondrial fusion and normalized mitochondrial dynamics, thereby reversing LPS-induced mitochondrial dysfunction, fibroblast apoptosis, and viability and migration inhibition in HDF-a cells. These data support a mechanism wherein HAX-1 plays a crucial role in LPS-induced fibroblast apoptosis in a mitochondria-dependent manner.

CCL20-CCR6 axis modulated traumatic brain injury-induced visual pathologies.

BACKGROUND: Traumatic brain injury (TBI) is a major cause of death and disability in the USA and the world; it constitutes 30% of injury-related deaths (Taylor et al., MMWR Surveill Summ 66:1-16, 2017). Contact sports athletes often experience repetitive TBI (rTBI), which exerts a cumulative effect later in life. Visual impairment is a common after-effect of TBI. Previously, we have shown that C-C chemokine 20 (CCL20) plays a critical role in neurodegeneration and inflammation following TBI (Das et al., J Neuroinflammation 8:148, 2011). C-C chemokine receptor 6 (CCR6) is the only receptor that CCL20 interacts with. The objective of the present study was to investigate the role of CCL20-CCR6 axis in mediating rTBI-induced visual dysfunction (TVD). METHODS: Wild type (WT) or CCR6 knock out (CCR6-/-) mice were subjected to closed head rTBI. Pioglitazone (PG) is a peroxisome proliferator-activated receptor γ (PPARγ) agonist which downregulates CCL20 production. Subsets of WT mice were treated with PG following final rTBI. A subset of mice was also treated with anti-CCL20 antibody to neutralize the CCL20 produced after rTBI. Histopathological assessments were performed to show cerebral pathologies, retinal pathologies, and inflammatory changes induced by rTBI. RESULTS: rTBI induced cerebral neurodegeneration, retinal degeneration, microgliosis, astrogliosis, and CCL20 expression. CCR6-/- mice showed reduced retinal degeneration, microgliosis, and inflammation. Treatment with CCL20 neutralization antibody or PG showed reduced CCL20 expression along with reduced retinal degeneration and inflammation. rTBI-induced GFAP-positive glial activation in the optic nerve was not affected by knocking out CCR6. CONCLUSION: The present data indicate that rTBI-induced retinal pathology is mediated at least in part by CCL20 in a CCR6-dependent manner.

Elevated potassium outward currents in hyperoxia treated atrial cardiomyocytes.

Supplementation of 100% oxygen is a very common intervention in intensive care units (ICU) and critical care centers for patients with dysfunctional lung and lung disorders. Although there is advantage in delivering sufficient levels of oxygen, hyperoxia is reported to be directly associated with increasing in-hospital deaths. Our previous studies reported ventricular and electrical remodeling in hyperoxia treated mouse hearts, and in this article, for the first time, we are investigating the effects of hyperoxia on atrial electrophysiology using whole-cell patch-clamp electrophysiology experiments along with assessment of Kv1.5, Kv4.2, and KChIP2 transcripts and protein profiles using real-time quantitative RT-PCR and Western blotting. Our data showed that induction of hyperoxia for 3 days in mice showed larger outward potassium currents with shorter action potential durations (APD). This increase in current densities is due to significant increase in ultrarapid delayed rectifier outward K+ currents (IKur ) and rapidly activating, rapidly inactivating transient outward K+ current (Ito ) densities. We also observed a significant increase in both transcripts and protein levels of Kv1.5 and KChIP2 in hyperoxia treated atrial cardiomyocytes, whereas no significant change was observed in Kv4.2 transcripts or protein. The data presented here further support our previous findings that hyperoxia induces not only ventricular remodeling, but also atrial electrical remodeling.

Evaluation of a Paradigm to Investigate Detection of Road Hazards when Using a Bioptic Telescope.

SIGNIFICANCE: A new driving simulator paradigm was developed and evaluated that will enable future investigations of the effects of the ring scotoma in bioptic drivers with diverse vision impairments and different telescope designs. PURPOSE: The ring scotoma may impair detection of peripheral hazards when viewing through a bioptic telescope. To investigate this question, we developed and tested a sign-reading and pedestrian-detection paradigm in a driving simulator. METHODS: Twelve normally sighted subjects with simulated acuity loss (median 20/120) used a 3.0× monocular bioptic to read 36 road signs while driving in a simulator. Thirteen of 21 pedestrian hazards appeared and ran on the road for 1 second within the ring scotoma while participants were reading signs through the bioptic. Head movements were analyzed to determine whether the pedestrian appeared before or only while using the bioptic. Six subjects viewed binocularly, and six viewed monocularly (fellow eye patched). Two patients with real visual acuity loss in one eye and no light perception in the other performed the same tasks using their own telescopes. RESULTS: For the monocular simulated acuity loss group, detection rates were significantly higher when the pedestrian appeared before using the bioptic than when it appeared while using the bioptic and was likely within the area of the ring scotoma (77% vs. 28%, P < .001). For the binocular simulated acuity loss group, there was no significant difference in detection rates for pedestrians that appeared before or while using the bioptic (80% vs. 91%, P = .20). The two monocular patients detected only 17% of pedestrians that appeared while looking through the bioptic. CONCLUSIONS: Our results confirm the utility of the testing paradigm and suggest that the fellow eye of normally sighted observers with simulated acuity loss was able to compensate for the ring scotoma when using a monocular bioptic telescope in a realistic driving task.

Automated synthesis of N-(2-[18 F]Fluoropropionyl)-l-glutamic acid as an amino acid tracer for tumor imaging on a modified [18 F]FDG synthesis module.

N-(2-[18 F]Fluoropropionyl)-l-glutamic acid ([18 F]FPGLU) is a potential amino acid tracer for tumor imaging with positron emission tomography. However, due to the complicated multistep synthesis, the routine production of [18 F]FPGLU presents many challenging laboratory requirements. To simplify the synthesis process of this interesting radiopharmaceutical, an efficient automated synthesis of [18 F]FPGLU was performed on a modified commercial fluorodeoxyglucose synthesizer via a 2-step on-column hydrolysis procedure, including 18 F-fluorination and on-column hydrolysis reaction. [18 F]FPGLU was synthesized in 12 ± 2% (n = 10, uncorrected) radiochemical yield based on [18 F]fluoride using the tosylated precursor 2. The radiochemical purity was ≥98%, and the overall synthesis time was 35 minutes. To further optimize the radiosynthesis conditions of [18 F]FPGLU, a brominated precursor 3 was also used for the preparation of [18 F]FPGLU, and the improved radiochemical yield was up to 20 ± 3% (n = 10, uncorrected) in 35 minutes. Moreover, all these results were achieved using the similar on-column hydrolysis procedure on the modified fluorodeoxyglucose synthesis module.

Data Acquisition Based on Stable Matching of Bipartite Graph in Cooperative Vehicle-Infrastructure Systems.

Existing studies on data acquisition in vehicular networks often take the mobile vehicular nodes as data carriers. However, their autonomous movements, limited resources and security risks impact the quality of services. In this article, we propose a data acquisition model using stable matching of bipartite graph in cooperative vehicle-infrastructure systems, namely, DAS. Contents are distributed to roadside units, while vehicular nodes support supplementary storage. The original distribution problem is formulated as a stable matching problem of bipartite graph, where the data and the storage cells compose two sides of vertices. Regarding the factors relevant with the access ratio and delay, the preference rankings for contents and roadside units are calculated, respectively. With a multi-replica preprocessing algorithm to handle the potential one-to-many mapping, the matching problem is addressed in polynomial time. In addition, vehicular nodes carry and forward assistant contents to deliver the failed packets because of bandwidth competition. Furthermore, an incentive strategy is put forward to boost the vehicle cooperation and to achieve a fair bandwidth allocation at roadside units. Experiments show that DAS achieves a high access ratio and a small storage cost with an acceptable delay.

Data Aggregation Based on Overlapping Rate of Sensing Area in Wireless Sensor Networks.

Wireless sensor networks are required in smart applications to provide accurate control, where the high density of sensors brings in a large quantity of redundant data. In order to reduce the waste of limited network resources, data aggregation is utilized to avoid redundancy forwarding. However, most of aggregation schemes reduce information accuracy and prolong end-to-end delay when eliminating transmission overhead. In this paper, we propose a data aggregation scheme based on overlapping rate of sensing area, namely AggOR, aiming for energy-efficient data collection in wireless sensor networks with high information accuracy. According to aggregation rules, gathering nodes are selected from candidate parent nodes and appropriate neighbor nodes considering a preset threshold of overlapping rate of sensing area. Therefore, the collected data in a gathering area are highly correlated, and a large amount of redundant data could be cleaned. Meanwhile, AggOR keeps the original entropy by only deleting the duplicated data. Experiment results show that compared with others, AggOR has a high data accuracy and a short end-to-end delay with a similar network lifetime.

Retinal cross talk in the mammalian visual system.

The existence and functional relevance of efferent optic nerve fibers in mammals have long been debated. While anatomical evidence for cortico-retinal and retino-retinal projections is substantial, physiological evidence is lacking, as efferent fibers are few in number and are severed in studies of excised retinal tissue. Here we show that interocular connections contribute to retinal bioelectrical activity in adult mammals. Full-field flash electroretinograms (ERGs) were recorded from one or both eyes of Brown-Norway rats under dark-adapted (n = 16) and light-adapted (n = 11) conditions. Flashes were confined to each eye by an opaque tube that blocked stray light. Monocular flashes evoked a small (5-15 µV) signal in the nonilluminated eye, which was named "crossed ERG" (xERG). The xERG began under dark-adapted conditions with a positive (xP1) wave that peaked at 70-90 ms and ended with slower negative (xN1) and positive (xP2) waves from 200 to 400 ms. xN1 was absent under light-adapted conditions. Injection of tetrodotoxin in either eye (n = 15) eliminated the xERG. Intraocular pressure elevation of the illuminated eye (n = 6) had the same effect. The treatments also altered the ERG b-wave in both eyes, and the alterations correlated with xERG disappearance. Optic nerve stimulation (n = 3) elicited a biphasic compound action potential in the nonstimulated nerve with 10- to 13-ms latency, implying that the xERG comes from slow-conducting (W type) fibers. Monocular dye application (n = 7) confirmed the presence of retino-retinal ganglion cells in adult rats. We conclude that mammalian eyes communicate directly with each other via a handful of optic nerve fibers. The cross talk alters retinal activity in rats, and perhaps other animals.

Synthesis and preliminary biological evaluation of S-11C-methyl-D-cysteine as a new amino acid PET tracer for cancer imaging.

S-(11)C-methyl-L-cysteine (LMCYS) is an attractive amino acid tracer for clinical tumor positron emission tomography (PET) imaging. D-isomers of some radiolabeled amino acids are potential PET tracers for tumor imaging. In this work, S-(11)C-methyl-D-cysteine (DMCYS), a D-amino acid isomer of S-(11)C-methyl-cysteine for tumor imaging was developed and evaluated. DMCYS was prepared by (11)C-methylation of the precursor D-cysteine, with an uncorrected radiochemical yield over 50 % from (11)CH3I within a total synthesis time from (11)CO2 about 12 min. In vitro competitive inhibition studies showed that DMCYS uptake was primarily transported through the Na(+)-independent system L, and also the Na(+)-dependent system B(0,+) and system ASC, with almost no system A. In vitro incorporation experiments indicated that almost no protein incorporation was found in Hepa 1-6 hepatoma cell lines. Biodistribution studies demonstrated higher uptake of DMCYS in pancreas and liver at 5 min post-injection, relatively lower uptake in brain and muscle, and faster radioactivity clearance from most tissues than those of L-isomer during the entire observation time. In the PET imaging of S180 fibrosarcoma-bearing mice and turpentine-induced inflammatory model mice, 2-(18)F-fluoro-2-deoxy-D-glucose (FDG) exhibited significantly high accumulation in both tumor and inflammatory lesion with low tumor-to-inflammation ratio of 1.40, and LMCYS showed low tumor-to-inflammation ratio of 1.64 at 60 min post-injection. By contrast, DMCYS showed moderate accumulation in tumor and very low uptake in inflammatory lesion, leading to relatively higher tumor-to-inflammation ratio of 2.25 than (11)C-methyl-L-methionine (MET) (1.85) at 60 min post-injection. Also, PET images of orthotopic transplanted glioma models demonstrated that low uptake of DMCYS in normal brain tissue and high uptake in brain glioma tissue were observed. The results suggest that DMCYS is a little better than the corresponding L-isomers as a potential PET tumor-detecting agent and is superior to MET and FDG in the differentiation of tumor from inflammation.

Investigation of the disinfection efficiency of commercial hydrogen peroxide, chlorine dioxide, and chlorine disinfectant on different surfaces.

OBJECTIVE: The disinfection efficiency of disinfectants differs in specific conditions. This study aimed to investigate the disinfection efficiency of commercial hydrogen peroxide, chlorine dioxide, and chlorine disinfectant on real field surfaces and provide data for precise disinfection. METHODS: Simulated field disinfection and field disinfection methods were conducted to quantitatively evaluate the disinfection efficiency of hydrogen peroxide, chlorine dioxide, and sodium dichloroisocyanurate. The log10 reduction of biological indicators, Escherichia coli (ATCC 8099) and Staphylococcus aureus (ATCC 6538), was calculated. Next, the reduction in natural bacteria on the surfaces of a food production and processing workshop and a biosafety laboratory was determined. RESULTS: The 3 commercial disinfectants evaluated were effective against E coli and S aureus, with a reduction of more than 3.00 log10 colony-forming units/mL tested for an exposure time of 15 minutes with 3.5% hydrogen peroxide, 100 mg/L chlorine dioxide, and 250 mg/L sodium dichloroisocyanurate. The natural load in the food production and processing workshop decreased by more than 90% using 10.5% hydrogen peroxide with an exposure time of 30 minutes. The same disinfection level in the biosafety level 2 laboratory was achieved by 500 mg/L chlorine dioxide at an exposure time of 60 minutes and 450 mg/L sodium dichloroisocyanurate at 60 minutes. CLINICAL RELEVANCE: This study provides a reference for precise disinfection of surfaces in the food industry and biosafety laboratories.

The study of loading mode with in-vitro fatigue testing for mitral annuloplasty ring.

To maintain the physiological dynamics of the mitral annulus, mitral annuloplasty rings (MAR) must be flexible. Enhanced flexibility implies decreased resistance to fatigue and potential for fatigue fracture. This study established new methods to test the flexible fatigue life of MAR in-vitro using numerical analysis; the purpose is that the fatigue test could reflect the real stress distribution in-vivo. Based on the conventional test methods (C1, D1), this paper presents a novel test method (C2, D2). Four testing methods for open-end annuloplasty rings (C1, C2) and closed-end annuloplasty rings (D1, D2) were modelled and their stress distribution calculated by finite element analysis. The mean absolute error (Χ) and the Pearson correlation coefficient (Φ) were used to quantify the difference in stress distribution between the loading modes in-vivo and in-vitro. For closed-end annuloplasty rings, the novel test method (D2) is not obvious better than conventional test methods(D1) in duplicating the stress distribution (ΦD1 = 0.88 vs ΦD2 = 0.92). However, the maximum values of stress in the novel test method are closer to the maximum value of stress under in-vivo loading (ΧD1 = 5.2Mpa vs ΧD2 = 4.4Mpa). For open-end annuloplasty rings, the novel test method(C2) is obviously superior to the conventional test method(C1) in duplicating both the stress distribution and the stress peak values of the in-vivo loading (ΦC1 = 0.22 vs ΦC2 = 0.98; ΧC1 = 59.1Mpa vs ΧC2 = 11.0Mpa). The in-vitro loading methods described in this article more closely approximated in-vivo conditions compared to traditional methods. They are simpler to operate, more efficient and can help manufacturers expedite new product development, assist regulatory agencies with product quality oversight.

Effect of Resveratrol on MMP-2 Expression in Scleral Fibroblasts: An In Vitro Study.

PURPOSE: To investigate the effects of resveratrol (Res) on human fetal scleral fibroblasts (HFSFs) and its potential mechanism. METHODS: HFSFs were randomly divided into the Res-treated group and the control group. Following, HFSFs were treated with or without a concentration of 10 µM Res for 48 h. To detect the expression of related genes, reverse transcription quantitative PCR (RT-qPCR) and western blotting were used. The apoptosis rate of different groups was determined using flow cytometry. RESULTS: The mRNA expression of matrix metalloproteinase 2 (MMP-2), Collagen, Type I, Alpha 1 (COL1A1), Janus Kinase 2 (JAK2), and Signal Transducer and Activator of Transcription 3 (STAT3)" was downregulated in the Res-treatment group compared to the control group, according to RT-qPCR. Western blotting revealed that Res therapy reduced the expression of MMP-2, JAK2, P-JAK2, STAT3, P-STAT3, and Bcl-2 associated protein X (Bax) while increasing the expression of COL1A1 and B-cell lymphoma-2 (Bcl-2). Flow cytometry showed that the cell apoptosis rate was significantly lower in HFSFs treated with Res. CONCLUSIONS: In conclusion, these findings suggest that Res increases COL1A1 expression while inhibiting MMP-2 and cell apoptosis in HFSFs, possibly through modulation of the JAK2/STAT3 signaling pathway.

Exploring the performance of protected areas in alleviating future human pressure.

Protected areas (PAs) are effective in mitigating human pressures, yet their future pressure alleviating effects remain unclear. In this study, we employed the ConvLSTM model to forecast the future human footprint and analyzed human pressure trends using Theil-Sen median and Mann-Kendall tests. We further evaluated the mitigating effects of PAs within their buffer zones (1-10 km) and the contributions of different IUCN categories of PAs to mitigating human pressure using linear regression models. The results indicate that by 2035, the average human pressure value is expected to increase by 11%, with trends exhibiting a polarized pattern. Furthermore, PAs also effectively mitigate human pressure within their 1 km buffer zones. Different categories of PAs vary in their effectiveness in mitigating human pressure, and stricter conservation areas are not always the most effective. This study can offer insights for evaluating the effectiveness of PAs in reducing human pressure and advocate for their targeted management in urban areas.

Deep learning-based label-free imaging of lymphatics and aqueous veins in the eye using optical coherence tomography.

We demonstrate an adaptation of deep learning for label-free imaging of the micro-scale lymphatic vessels and aqueous veins in the eye using optical coherence tomography (OCT). The proposed deep learning-based OCT lymphangiography (DL-OCTL) method was trained, validated and tested, using OCT scans (23 volumetric scans comprising 19,736 B-scans) from 11 fresh ex vivo porcine eyes with the corresponding vessel labels generated by a conventional OCT lymphangiography (OCTL) method based on thresholding with attenuation compensation. Compared to conventional OCTL, the DL-OCTL method demonstrates comparable results for imaging lymphatics and aqueous veins in the eye, with an Intersection over Union value of 0.79 ± 0.071 (mean ± standard deviation). In addition, DL-OCTL mitigates the imaging artifacts in conventional OCTL where the OCT signal modelling was corrupted by the tissue heterogeneity, provides ~ 10 times faster processing based on a rough comparison and does not require OCT-related knowledge for correct implementation as in conventional OCTL. With these favorable features, DL-OCTL promises to improve the practicality of OCTL for label-free imaging of lymphatics and aqueous veins for preclinical and clinical imaging applications.

Noninvasive positron emission tomography imaging of cell death using a novel small-molecule probe, (18)F labeled bis(zinc(II)-dipicolylamine) complex.

The synthetic bis(zinc(II)-dipicolylamine) (DPAZn2) coordination complexes are known to have a high specific and selective affinity to target the exposed phosphatidylserine (PS) on the surface of dead and dying cells. An (18)F-labeled DPAZn2 complex (4-(18)F-Fluoro-benzoyl-bis(zinc(II)-dipicolylamine), (18)F-FB-DPAZn2) as positron emission tomography (PET) tracer was developed and evaluated for in vivo imaging of tumor treated with a chemical agent. The in vitro cell stain studies revealed that fluorescent DPAZn2 complexes (Dansyl-DPAZn2) stained the same cells (apoptotic and necrotic cells) as fluorescein isothiocyanate (FITC) labeled Annexin V (FITC-Annexin V). The radiosynthesis of (18)F-FB-DPAZn2 was achieved through the amidation the precursor bis(2,2'-dipicolylamine) derivative (DPA2) with the prosthetic group N-succinimidyl-4-[(18)F]-fluorobenzoate ((18)F-SFB) and chelation with zinc nitrate. In the biodistribution study, the fast clearance of (18)F-FB-DPAZn2 from blood and kidney was observed and high uptake in liver and intestine within 90 min postinjection was also found. For the PET imaging, significantly higher tumor uptake of (18)F-FB-DPAZn2 was observed in the adriamycin (ADM)-treated Hepa1-6 hepatocellular carcinoma-bearing mice than that in the untreated tumor-model mice, while a slightly decreased tumor uptake of (18)F-FDG was found in the ADM-treated tumor-bearing mice. The results indicate that (18)F-FB-DPAZn2 has the similar capability of apoptosis detection as FITC-Annexin V and seems to be a potential PET tracer for noninvasive evaluation and monitoring of anti-tumor chemotherapy. The high uptake of (18)F-FB-DPAZn2 in the abdomen needs to optimize the structure for improving its pharmacokinetics characteristics in the future work.

Aeromonas caviae-Associated Severe Bloody Diarrhea.

Aeromonas species are capable of inducing severe infections in both immunocompetent and immunocompromised individuals. Gastroenteritis is the most common infection associated with Aeromonas species in humans. We report a rare case of Aeromonas caviae severe gastroenteritis and bloody diarrhea that led to the development of sepsis in a 45-year-old female with no history of immunocompromising conditions. This patient required extensive medical support which included blood transfusions and antibiotics. Fortunately, with appropriate diagnostic measures and targeted antibiotic therapy, her symptoms resolved. Aeromonas species are becoming increasingly frequent among the pathogens isolated from patients suffering from gastroenteritis. As such, it is becoming increasingly important for clinicians to consider this pathogen when working up their patients for diarrhea.

Bactericidal efficacy of mobile ultraviolet-C disinfection devices in reducing contamination in biosafety laboratories.

INTRODUCTION: Biosafety research requires a wide range of microorganisms and thorough disinfection to prevent laboratory infection is often required. Ultraviolet-C (UV-C) exposure reduces bacterial and viral concentrations. Therefore, in this study, we aimed to evaluate the efficacy of a mobile UV-C device as a non-contact disinfection strategy. METHODOLOGY: The bactericidal efficacy of the UV-C device was determined based on log10 decreases in the relative abundances of bacterial indicators, including Escherichia coli, Staphylococcus aureus, Staphylococcus albus, and Pseudomonas aeruginosa at 0.5 and 1.0 m after irradiation for 30, 60, and 90 min. Next, the reduction of natural bacteria in air and on surface as a result of the UV-C device exposure in the laboratory were determined. RESULTS: Exposure to the UV-C disinfection device resulted in mean log10 decreases in microbial contamination of 3.55 and 5.85 following irradiation for 30 and 90 min, respectively, at a distance of 0.5 m. Further, P. aeruginosa and E. coli were the most and least sensitive to UV-C exposure, respectively. The bacterial load in air decreased by 65.53% after 60 min of irradiation, while those on surfaces decreased by 44.19% and 78.23% after 30 and 60 min of irradiation, respectively. CONCLUSIONS: The UV-C device effectively reduced bacterial load after irradiation for over 60 min. Further studies are encouraged to determine the effectiveness of the UV-C disinfection device in frequently occupied institutions, such as primary medical, health, and nursery, and its efficiency in infection control.