Vagus nerve stimulation attenuates septic shock-induced cardiac injury in rats

This research aimed to evaluate whether vagus nerve stimulation (VNS) could effectively prevent septic shock-induced cardiac injury in rats and investigate the potential mechanisms. Female Sprague-Dawley rats were divided into the Sham group (sham cecal ligation and puncture [CLP] plus vagal nerve trunk separation), the Vehicle group (CLP plus vagal nerve trunk separation), and the VNS groups (CLP plus vagal nerve trunk separation plus VNS). The left ventricular function was analyzed by echocardiography. Histologic examinations of the cardiac tissues were performed through hematoxylin and eosin staining and TUNEL staining. The Vehicle group had worse cardiac function, higher levels of cardiac injury markers, and enhanced myocardial apoptosis than the Sham group. The rats in the VNS groups had enhanced cardiac function, lower levels of cardiac injury markers, and inhibited myocardial apoptosis than those in the Vehicle group. Elevated interleukin-1beta and tumor necrosis factor-alpha-levels and activated nuclear factor kappa B (NF-kappa-B) signal in septic shock rats were inhibited by the performance of VNS. This study suggests that VNS contributes to the reduction of myocardial apoptosis and improvement of left ventricular function to attenuate septic shock-induced cardiac injury in rats. The performance of VNS inhibits the inflammatory responses in heart tissues via the regulation of NF-kappa-B signal.

An NIR-II Probe with High PSMA Affinity Demonstrates an Unexpected Excellent Bone Imaging Ability

(S)-3-(Carboxyformamido)-2-(3-(carboxymethyl)ureido)propanoic acid (EuK) is a known binder toward the prostate-specific membrane agent (PSMA) with strong affinity, making it a popular choice for prostate cancer medicine development. However, during the probe modification, a new EuK-based PSMA tetramer, Bone-1064, was discovered to have an unexpected and intense uptake in bone, which has not yet been reported in any previous studies yet. After administration, Bone-1064 allowed for high contrast visualization of the bone from surrounding tissues with a signal-to-background ratio of 10.22 at 24 h postinjection. In contrast, the tumor had a blurry contour, and the maximum tumor-to-normal-tissue ratio was only 2.22. Further imaging studies revealed that Bone-1064 binds specifically to hydroxyapatite in bone tissues, instead of PSMA. Overall, Bone-1064 is an excellent bone probe with a unique structure that can be used for NIR-II fluorescence imaging in animal models. Meanwhile, this modification study might also inspire further PSMA probe designations.

[The clinical application value of brain 18F-FDG PET/CT in the diagnostics of Parkinsonian syndromes]

Objective: To analyze the PET/CT imaging features of fluoride 18F-fluorodeoxyglucose (18F-FDG) in patients with various types of Parkinson's syndrome (PS), and to establish a "diagnostic tree" model of 18F-FDG PET/CT for PS. Methods: Data of patients with Parkinson's disease (PD), patients with multiple system atrophy cerebellar type (MSA-C), and patients with multiple system atrophy Parkinson's type (MSA-P)admitted to the Neurology Department of Huashan Hospital affiliated to Fudan University from January 2019 to December 2021. 18F-FDG PET/CT examination was conducted in all patients. Clinical and follow-up data was collected to determine clinical diagnosis. The specific patterns of brain glucose metabolism in patients with various types of Parkinsonism were observed and their utility in the differential diagnosis of the disease was analyzed. 18F-FDG PET/CT imaging"diagnostic tree"model was established and its value in the differential diagnosis of Parkinsonism was verified. Results: A total of 320 patients, 187 males and 133 females, aged (62±9) years, were enrolled in our study, including 80 PD, 90 PSP, 114 MSA-C and 36 MSA-P patients. The differential diagnostic features of cerebral glucose metabolism of Parkinsonism were as follows: the metabolism of putamen increased in PD patients, the metabolism of caudate nucleus, thalamus, midbrain, and frontal lobe decreased in PSP patients, the metabolism of cerebellum decreased in MSA-C patients, and the metabolism of putamen and cerebellum decreased in MSA-P patients. The sensitivity and specificity of the"diagnostic tree"model are 88.75% and 91.25% for PD diagnosis, 54.44% and 96.96% for PSP diagnosis, 87.72% and 86.41% for MSA-C diagnosis, and 55.56% and 91.55% for MSA-P diagnosis, respectively. It could correctly classify 75%(240/320) of patients. Conclusions: Characteristic metabolism patterns of brain in 18F-FDG PET/CT imaging is significant for the differential diagnosis of PD, PSP, MSA-C and MSA-P. The"diagnostic tree"model is valuable for clinical diagnosis.

Synthesis and Bioevaluation of 2-Styrylquinoxaline Derivatives as Tau-PET Tracers

This study focused on designing and evaluating Tau-PET tracers for noninvasive positron emission computed tomography (PET) imaging of neurofibrillary tangles (NFTs), a hallmark pathology of Alzheimer's disease (AD). The tracers were synthesized with a 2-styrylquinoxaline scaffold and varying lengths of FPEG chains. The compound [18F]15, which had two ethoxy units, showed high affinity for recombinant K18-Tau aggregates (Ki = 41.48 nM) and the highest selectivity versus Aβ1-42 aggregates (8.83-fold). In vitro autoradiography and fluorescent staining profiles further validated the binding of [18F]15 or 15 toward NFTs in brain sections from AD patients and Tau-transgenic mice. In normal ICR mice, [18F]15 exhibited an ideal initial brain uptake (11.21% ID/g at 2 min) and moderate washout ratio (2.29), and micro-PET studies in rats confirmed its ability to penetrate the blood-brain barrier with the peak SUV value of 1.94 in the cortex. These results suggest that [18F]15 has the potential to be developed into a useful Tau-PET tracer for early AD diagnosis and evaluation of anti-Tau therapeutics.

Structure-Activity Relationships of Cyano-substituted Indole Derivatives as Ligands for α-Synuclein Aggregates

α-Synuclein (α-syn) is an essential biomarker for synucleinopathies, including Parkinson's disease (PD), dementia with Lewy bodies (DLB), and multiple system atrophy (MSA). The development of α-syn imaging probes is of great importance for understanding the pathogenesis mechanism and developing new therapies. In this study, we designed and synthesized a series of cyano-substituted indole derivatives and evaluated their potency to bind to α-syn fibrils by in vitro fibril binding assays. We carried out systematic structure-activity relationship (SAR) studies and obtained a promising candidate 51. The results showed that 51 bound to α-syn fibrils with the affinity of 17.4 ± 5.6 nM, and the biodistribution experiments in normal mice showed [125I]51 exhibited a moderate brain uptake of 3.57 ± 0.28% ID/g at 2 min after injection. In conclusion, the indole derivative [125I]51 showed initial potential as α-syn imaging probes, which needed further development.

Synthesis, Preclinical Evaluation, and First-in-Human PET Study of [68Ga]-Labeled Biphenyl-Containing PSMA Tracers

Radioisotope-labeled prostate-specific membrane antigen (PSMA) PET tracers have gained popularity in diagnosing prostate cancer (PCa). This study aimed to improve the affinity and tumor-targeting capabilities of new PSMA tracers by increasing the number of pharmacophores that specifically bind to PSMA. Using biphenyl as a core scaffold, we investigated the relationship among spacer segments, affinity, and pharmacokinetic properties. In preclinical PET studies on mice with 22Rv1 tumors, compared with [68Ga]Ga-PSMA-11 (SUVmax = 3.37), [68Ga]Ga-PSMA-D5 (Ki = 0.15) showed higher tumor uptake (SUVmax = 3.51) and lower renal uptake (T/K = 1.84). In the first-in-human study, [68Ga]Ga-PSMA-D5 effectively detected small PCa-associated lesions and distant metastases. The advantages of [68Ga]Ga-PSMA-D5 include high tumor uptake, straightforward synthesis, and labeling, making it a promising PSMA PET tracer. Furthermore, [68Ga]Ga-PSMA-D5 contains a DOTA chelator, allowing convenient labeling with therapeutic radionuclides such as 177Lu and 225Ac, providing the potential for targeted radioligand therapy in PCa.

Hydroxyethyl-Modified Cycloheptatriene-BODIPY Derivatives as Specific Tau Imaging Probes

Near-infrared fluorescence (NIRF) imaging as an exquisite sensitive, high spatial-resolution, and real-time tool plays an important role in visualizing pathologies in the brain. In this study, we designed and synthesized a series of NIR probes of hydroxyethyl cycloheptatriene-BODIPY derivatives that have demonstrated strong binding specificity to native neurofibrillary tangles (NFTs) in Alzheimer's disease (AD) brain sections. The improved hydrophilicity of TNIR7-9 and TNIR7-11 resulted in faster clearance rates from healthy brains (4.2 and 10.9, respectively) compared to previously reported compounds. Furthermore, TNIR7-13, which features a fluorinated modification, exhibited a high binding affinity to Tau aggregates (Kd = 11.8 nM) and held promise for future PET studies.

[Comparison of diagnostic performance of Clear Cell Likelihood Score v1.0 and v2.0 for clear renal cell carcinoma]

OBJECTIVE

To compare the performance of Clear Cell Likelihood Score (ccLS) v1.0 and v2.0 in diagnosing clear cell renal cell carcinoma (ccRCC) from small renal masses (SRM).

METHODS

We retrospectively analyzed the clinical data and MR images of patients with pathologically confirmed solid SRM from the First Medical Center of the Chinese PLA General Hospital between January 1, 2018, and December 31, 2021, and from Beijing Friendship Hospital of Capital Medical University and Peking University First Hospital between January 1, 2019 and May 17, 2021. Six abdominal radiologists were trained for use of the ccLS algorithm and scored independently using ccLS v1.0 and ccLS v2.0. Random- effects logistic regression modeling was used to generate plot receiver operating characteristic curves (ROC) to evaluate the diagnostic performance of ccLS v1.0 and ccLS v2.0 for ccRCC, and the area under curve (AUC) of these two scoring systems were compared using the DeLong's test. Weighted Kappa test was used to evaluate the interobserver agreement of the ccLS score, and differences in the weighted Kappa coefficients was compared using the Gwet consistency coefficient.

RESULTS

In total, 691 patients (491 males, 200 females; mean age, 54 ± 12 years) with 700 renal masses were included in this study. The pooled accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of ccLS v1.0 for diagnosing ccRCC were 77.1%, 76.8%, 77.7%, 90.2%, and 55.7%, as compared with 80.9%, 79.3%, 85.1%, 93.4%, 60.6% with ccLS v2.0, respectively. The AUC of ccLS v2.0 was significantly higher than that of ccLS v1.0 for diagnosis of ccRCC (0.897 vs 0.859; P < 0.01). The interobserver agreement did not differ significantly between ccLS v1.0 and ccLS v2.0 (0.56 vs 0.60; P > 0.05).

CONCLUSION

ccLS v2.0 has better performance for diagnosing ccRCC than ccLS v1.0 and can be considered for use to assist radiologists with their routine diagnostic tasks.

Synthesis and Preclinical Evaluation of 2-(4-[18F]Fluorophenyl)imidazo[1,2-h][1,7]naphthyridine ([18F]FPND-4): An Aza-Fused Tricyclic Derivative as Positron Emission Tomography Tracer for Neurofibrillary Tangle Imaging

Tau accumulation is one of the predominant neuropathological biomarkers for in vivo diagnosis of Alzheimer's disease due to its high correlation with disease progression. In this study, we focused on the structure-activity relationship study of the substituent effect on the aza-fused tricyclic core imidazo[1,2-h][1,7]naphthyridine to screen ¹⁸F-labeled Tau tracers. Through a series of autoradiographic studies and biological evaluations, 4-[¹⁸F]fluorophenyl-substituted tracer [¹⁸F]13 ([¹⁸F]FPND-4) was identified as a promising candidate with high affinity to native Tau tangles (IC₅₀ = 2.80 nM), few appreciable binding to Aβ plaques and MAO-A/B. Validated by dynamic positron emission tomography (PET) imaging in rodents and rhesus monkey, [¹⁸F]13 displayed desirable brain uptake (SUV = 1.75 at 2 min), fast clearance (brain_2min/60min = 5.9), minimal defluorination, and few off-target binding, which met the requirements of a Tau-specific PET radiotracer.

Design and Characterization of Squaramic Acid-Based Prostate-Specific Membrane Antigen Inhibitors for Prostate Cancer

Prostate-specific membrane antigen (PSMA) overexpressed on prostate cancer (PCa) cells is a satisfactory theranostic target in PCa. To seek novel non-glutamate-urea-based PSMA inhibitors by the strategy of bioisosterism, 10 ligands were designed, synthesized, and characterized. Among them, ligands 17, 18, and 21-24 bearing the squaramic acid moiety proved to be potent PSMA inhibitors, with K_i values ranging from 0.40 to 2.49 nM, which are comparable or higher in inhibitory potency compared to previously reported glutamate-urea-based inhibitors. Docking studies of 15, 17, and 19 were carried out to explore their binding mode in the active site of PSMA. Two near-infrared (NIR) probes, 23 (λ_EM = 650 nm) and 24 (λ_EM = 1088 nm), displayed favorable in vivo NIR imaging and successful NIR-II image-guided tumor resection surgery in PSMA-positive tumor-bearing mice, which demonstrated the effectiveness of these new squaramic acid-based inhibitors.

Activated Microglia in the Early Stage of a Rat Model of Parkinson's Disease: Revealed by PET-MRI Imaging by [18F]DPA-714 Targeting TSPO

In the past decades, translocator protein (TSPO) has been considered as an in vivo biomarker to measure the presence of neuroinflammatory reactions. In this study, expression of TSPO was quantified via [¹⁸F]DPA-714 positron emission tomography-magnetic resonance imaging (PET-MRI) imaging to investigate the effects of microglial activation associated with motor behavioral impairments in the 6-hydroxydopamine (6-OHDA)-treated rodent model of Parkinson's disease (PD). [¹⁸F]FDG PET-MRI (for non-specific inflammation), [¹⁸F]D₆-FP-(+)-DTBZ PET-MRI (for damaged dopaminergic neurons), post-PET immunofluorescence, and Pearson's correlation analyses were also performed. The time course of the striatal [¹⁸F]DPA-714 binding ratio elevated in 6-OHDA-treated rats during 1-3 weeks post-treatment, with the peak TSPO binding in the 1st week. No differences between bilateral striatum in [¹⁸F]FDG PET imaging were found. Moreover, an obvious correlation between [¹⁸F]DPA-714 SUV_R^R/L and rotation numbers was found (r = 0.434, *p = 0.049). No correlation between [¹⁸F]FDG SUV_R^R/L and rotation behavior was found. [¹⁸F]DPA-714 appeared to be a potential PET tracer for imaging the microglia-mediated neuroinflammation in the early stage of PD.

Activated Microglia in the Early Stage of a Rat Model of Parkinson's Disease: Revealed by PET-MRI Imaging by [18F]DPA-714 Targeting TSPO

In the past decades, translocator protein (TSPO) has been considered as an in vivo biomarker to measure the presence of neuroinflammatory reactions. In this study, expression of TSPO was quantified via [¹⁸F]DPA-714 positron emission tomography-magnetic resonance imaging (PET-MRI) to investigate the effects of microglial activation associated with motor behavioral impairments in the 6-hydroxydopamine (6-OHDA)-treated rodent model of Parkinson's disease (PD). [¹⁸F]FDG PET-MRI (for non-specific inflammation), [¹⁸F]D₆-FP-(+)-DTBZ PET-MRI (for damaged dopaminergic (DA) neurons), post-PET immunofluorescence, and Pearson's correlation analyses were also performed. The time course of striatal [¹⁸F]DPA-714 binding ratio was elevated in 6-OHDA-treated rats during 1-3 weeks post-treatments, with peak TSPO binding in the 1st week. No difference between the bilateral striatum in [¹⁸F]FDG PET imaging were found. Moreover, an obvious correlation between [¹⁸F]DPA-714 SUV_R^R/L and rotation numbers was found (r = 0.434, *p = 0.049). No correlation between [¹⁸F]FDG SUV_R^R/L and rotation behavior was found. [¹⁸F]DPA-714 appeared to be a potential PET tracer for imaging the microglia-mediated neuroinflammation in the early stage of PD.

[The characteristics and correlations of vaginal flora in women with cervical lesions]

Objective: To explore the characteristics and correlations of vaginal flora in women with cervical lesions. Methods: A total of 132 women, including 41 women diagnosed with normal cervical (NC), 39 patients with low-grade cervical intraepithelial neoplasia (CIN 1), 37 patients with high-grade cervical intraepithelial neoplasia (CIN 2/3) and 15 patients with cervical squamous cell carcinoma (SCC), who came from the gynecological clinic of Second Hospital of Shanxi Medical University during January 2018 to June 2018, were enrolled in this study according to the inclusive and exclusive criteria strictly. The vaginal flora was detected by 16S rDNA sequencing technology. Co-occurrence network analysis was used to investigate the Spearman correlations between different genera of bacteria. Results: The dominant bacteria in NC, CIN 1 and CIN 2/3 groups were Lactobacillus [constituent ratios 79.4% (1 869 598/2 354 098), 63.6% (1 536 466/2 415 100) and 58.3% (1 342 896/2 301 536), respectively], while Peptophilus [20.4% (246 072/1 205 154) ] was the dominant bacteria in SCC group. With the aggravation of cervical lesions, the diversity of vaginal flora gradually increased (Shannon index: F=6.39, P=0.001; Simpson index: F=3.95, P=0.012). During the cervical lesion progress, the ratio of Lactobacillus gradually decreased, the ratio of other anaerobes such as Peptophilus, Sneathia, Prevotella and etc. gradually increased, and the differential bacteria (LDA score >3.5) gradually evolved from Lactobacillus to other anaerobes. The top 10 relative abundance bacteria, spearman correlation coefficient>0.4 and P<0.05 were selected. Co-occurrence network analysis showed that Prevotella, Peptophilus, Porphyrinomonas, Anaerococcus, Sneathia, Atopobium, Gardnerella and Streptococcus were positively correlated in different stages of cervical lesions, while Lactobacillus was negatively correlated with the above anaerobes. It was found that the relationship between vaginal floras in CIN 1 group was the most complex and only Peptophilus was significantly negatively correlated with Lactobacillus in SCC group. Conclusions: The increased diversity and changed correlations between vaginal floras are closely related to cervical lesions. Peptophilus is of great significance in the diagnosis, prediction and early warning of cervical carcinogenesis.

Fluorine-18-Labeled Diaryl-azines as Improved β-Amyloid Imaging Tracers: From Bench to First-in-Human Studies

The deposition of β-amyloid (Aβ) in the brain is a pathologic hallmark of Alzheimer's disease (AD), appearing years before the onset of symptoms, and its detection is incorporated into clinical diagnosis. Here, we have discovered and developed a class of diaryl-azine derivatives for detecting Aβ plaques in the AD brain using PET imaging. After a set of comprehensive preclinical assessments, we screened out a promising Aβ-PET tracer, [¹⁸F]92, with a high binding affinity to the Aβ aggregates, significant binding ability with the AD brain sections, and optimal brain pharmacokinetic properties in rodents and non-human primates. The first-in-human PET study declared that [¹⁸F]92 displayed low white matter uptake and could bind to Aβ pathology for distinguishing AD from healthy control subjects. All these results support that [¹⁸F]92 might become a promising PET tracer for visualizing Aβ pathology in AD patients.

Discovery and evaluation of aza-fused tricyclic derivatives for detection of Tau pathology in Alzheimer's disease

For various neurodegenerative diseases, including Alzheimer's disease (AD), the abnormal aggregation of Tau is not only the predominant contributing factor but also a major biomarker for disease diagnosis. In this study, a series of aza-fused tricyclic derivatives were designed and synthesized. By changing the position and number of nitrogen atoms on the fused tricyclic core, the imidazonaphthyridine scaffold was screened and reported for the first time which could potentially detect Tau aggregates. Through a series of in vitro and in vivo biological evaluations, probe [125I]5 possessed exceptional binding affinity (IC50 = 1.63 nM) to neurofibrillary tangles in the AD brain, high selectivity over Aβ plaques (23.4-fold), clean off-target profile to monoamine oxidase A/B (MAO-A/B), and suitable pharmacokinetics (initial brain uptake = 3.22% ID/g).

In vivo imaging of tau deposition in Alzheimer’s disease using both [18F]-THK5317 and [18F]-S16: A pilot human study

Objective

To evaluate the effectiveness of a new tracer (S)-1-(4-(6-(dimethylamino)quinoxalin-2-yl)phenoxy)-3-fluoropropan-2-ol ([¹⁸F]-S16), in distinguishing patients with AD from HCs.

Methods

Paired [¹⁸F]-S16 and [¹⁸F]-THK5317 scans were acquired in five patients with AD, six HCs, one subject with a semantic variant of primary progressive aphasia (sv-PPA) and one subject with probable progressive supranuclear palsy (PSP). Dynamic PET scanning was performed over 90 min after injection of the tracers. Standardized uptake values (SUV) and cortical-to-cerebellum standardized uptake value ratios (SUVRs) were used for tau deposition semi-quantization. A voxel-based analysis was employed to assess the uptake difference between populations.

Results

[¹⁸F]-S16 exhibited excellent blood-brain-barrier penetration. AD patients showed increased cortical [¹⁸F]-THK5317 and [¹⁸F]-S16 binding. Compared to HCs, AD patients showed significantly increased cortical [¹⁸F]-S16 uptake in the bilateral occipital cortex, posterior cingulated cortex/precuneus, and lateral frontal cortex. Notable [¹⁸F]-S16 uptake was observed in the basal ganglia and brainstem compared to the neocortex. A substantial [¹⁸F]-S16 signal was detected in the basal ganglia and midbrain in a patient with probable PSP and in the bilateral anterior temporal cortex in a sv-PPA patient.

Conclusion

[¹⁸F]-S16 might be of help to detect tau protein in vivo.

[Update on the medical management of parathyroid carcinoma]

Parathyroid carcinoma is a rare endocrine malignancy with an increasing rate of incidence. Most parathyroid carcinoma patients will develop local recurrence or metastases leading to poor prognosis. Medical management is the mainstay of treatment for patients with unresectable parathyroid carcinoma. However, the therapeutic outcome of medical management remains unsatisfactory restricted by limited options and efficacy. With the deepening of research, several novel drugs have been reported to be applied in the treatment of parathyroid carcinoma. Calcimimetics and receptor activator for nuclear factor-κB ligand inhibitors aiming to control hypercalcemia have been applied in the endocrine therapy of parathyroid carcinoma. Besides, preliminary studies have shown the therapeutic effects of targeted therapy and immunotherapy on parathyroid carcinoma. These new drugs have shed light on this clinical dilemma; however, their clinical efficacy remains to be determined. In this article, the recent progress in the medical management of parathyroid carcinoma is updated.

Current Progress in the Development of Probes for Targeting α-Synuclein Aggregates

α-Synuclein aggregates abnormally into intracellular inclusions in Parkinson's disease (PD), dementia with Lewy bodies (DLB), multiple system atrophy (MSA), and many other neurological disorders, closely connecting with their pathogenesis. The accurate tracking of α-synuclein by targeting probes is of great significance for early diagnosis, disease monitoring, and drug development. However, there have been no promising α-synuclein targeting probes for clinical application reported so far. This overview focuses on various potential α-synuclein targeting probes reported in the past two decades, including small-molecule fluorescent probes and radiolabeled probes. We provide the current status of the development of the small molecular α-synuclein imaging probes, including properties of promising imaging molecules, strategies of processing new probes, limited progress, and growth prospects in this field, expecting to help in the further development of α-synuclein targeting probes.

Biodistribution and Dosimetry Evaluation for a Novel Tau Tracer [18F]-S16 in Healthy Volunteers and Its Application in Assessment of Tau Pathology in Alzheimer’s Disease

Background: The goal of this study was to report a fully automated radiosynthetic procedure of a novel tau tracer [18F]-S16 and its safety, biodistribution, and dosimetry in healthy volunteers as well as the potential utility of [18F]-S16 positron emission tomography (PET) in Alzheimer’s disease (AD).

Methods: The automated radiosynthesis of [18F]-S16 was performed on a GE Tracerlab FX2 N module. For the biodistribution and dosimetry study, healthy volunteers underwent a series of PET scans acquired at 10, 60, 120, and 240 min post-injection. The biodistribution and safety were assessed. For the AD study, both AD and healthy controls (HCs) underwent dynamic [18F]-S16 and static [18F]-FDG PET imaging. [18F]-S16 binding was assessed quantitatively using standardized uptake value ratios (SUVRs) measured at different regions of interest (ROIs). [18F]-S16 SUVRs were compared between the AD patients and HCs using the Mann–Whitney U-test. In AD patients with all cortical ROIs, Spearman rank-correlation analysis was used to calculate the voxel-wise correlations between [18F]-S16 and [18F]-FDG.

Results: The automated radiosynthesis of [18F]-S16 was finished within 45 min, with a radiochemical yield of 30 ± 5% (n = 8, non-decay-corrected). The radiochemical purity was greater than 98%, and the specific activity was calculated to be 1,047 ± 450 GBq/μmol (n = 5), and [18F]-S16 was stable in vitro. In the healthy volunteer study, no adverse effect was observed within 24 h post-injection, and no defluorination was observed in vivo. The radiotracer could pass through the blood–brain barrier easily and was rapidly cleared from the circulation and excreted through the hepatic system. The whole-body mean effective dose was 15.3 ± 0.3 μSv/MBq. In AD patients, [18F]-S16 accumulation was identified as involving the parietal, temporal, precuneus, posterior cingulate, and frontal lobes. No specific [18F]-S16 cerebral uptake was identified in HCs. The SUVR of AD patients was significantly higher than that of HCs. No specific binding uptake was found in the choroid plexus, venous sinus, and white matter. A significant correlation was found between [18F]-S16 binding and hypometabolism across neocortical regions.

Conclusion: [18F]-S16 could be synthesized automatically, and it showed favorable biodistribution and safety in humans. [18F]-S16 PET indicated a high image quality for imaging tau deposition in AD and distinguishing AD from HCs.

[Effect of metformin combined with intermittent fasting on endoplasmic reticulum stress after cerebral ischemia-reperfusion in mice]

Objective: To explore the effect of metformin combined with intermittent fasting on endoplasmic reticulum stress after cerebral ischemia-reperfusion injury in mice. Methods: One hundred 10-Week-old healthy KM mice of SPF grade, weighing 25-28 g, were divided into 5 groups by the random number table method: sham group, focal cerebral ischemia group (I/R group), intermittent fasting group (IF group), metformin group (Met group), metformin+intermittent fasting group (Met+IF group). In IF group, food was provided ad libitum from 8∶00 to 16∶00 daily, but the mice were fasted for the rest of the time. In Met group, the mice underwent intraperitoneal injection of metformin (10 mg/kg). In Met+IF group, the mice received the same eating method as the IF group and the same method of metformin injection as Met Group. In Sham group, I/R group and IF group, the mice were intraperitoneally injected with equal volume of normal saline. Mice in all groups were not restricted to drinking water. Random plasma glucose and body weight changes in mice during preconditioning were monitored, and a focal cerebral ischemia-reperfusion model was established 14 days later. The cerebral infarction volume was measured after 1 hour of ischemia and 24 hours of reperfusion. The brain tissues of mice were subjected to Western blot to detect the contents of endoplasmic reticulum stress-related proteins, including glucose-regulated protein 78 (GRP78), C/EBP homologous protein (CHOP), and apoptosis proteins (Caspase-3 and Cleaved-caspase 3). Results: After different interventions, there was no significant difference in random plasma glucose changes among the four groups (all P<0.05). The blood glucose level of the mice in the Met+IF group was lower than the sham group, I/R group, IF group and Met group (all P<0.05). GRP78/β-actin in sham group, I/R group, IF group, Met group, IF+Met group were 0.48±0.05, 1.35±0.10, 0.94±0.05, 0.70±0.14, 0.41±0.37, respectively; CHOP/β-actin were 0.27±0.04, 1.03±0.03, 0.72±0.04, 0.63±0.04, 0.44±0.01, respectively; Caspase-3/β-actin were 0.51±0.04, 1.04±0.04, 0.83±0.03, 0.76±0.03, 0.63±0.05, respectively; Cleaved-Caspase-3/β-actin were 0.17±0.06, 1.01±0.20, 0.75±0.06, 0.51±0.12, 0.29±0.08, respectively, with statistically significant differences (all P<0.001). The counts of GRP78-positive cells in the hippocampus immunohistochemistry in the sham group, I/R group, IF group, Met group, and IF+Met group were 53±5, 192±11, 162±12, 140±10, 114±13, respectively, while the counts of CHOP-positive cells were 35±4, 177±12, 120±12, 100±7, 69±10, respectively, with statistically significant differences (all P<0.001). The relative volume of cerebral infarction in I/R group, IF group, Met group and IF+Met group were 0, 0.333±0.046, 0.258±0.023, 0.116±0.039, 0.111±0.039, respectively, and there were statistically significant differences (all P<0.001). Conclusion: Both Metformin and intermittent fasting can alleviate endoplasmic reticulum stress after cerebral ischemia and reperfusion in mice, and the combination of the two has a better effect.

[Clinical analysis of 10 cases with extramedullary plasmacytoma of the head and neck]

Objective: To explore the clinical characteristics, treatment methods and outcomes of extramedullary plasmacytoma of the head and neck. Methods: A retrospective analysis was conducted on 10 cases with extramedullary plasmacytoma of the head and neck who were admitted to Henan Tumor Hospital from January 2005 to January 2020. Among the 10 patients, 6 were male and 4 were female. The average age at diagnosis was 56.3 years old (34-74 years old). Among them, 3 cases were located in the nasal cavity, 2 cases in the nasopharynx, 1 case in the sinuses, 2 cases in the larynx, 1 case in the oropharynx, and 1 case in the cervical lymph nodes. Treatments were administered according to tumor size and resection extent. Complete surgical excision (negative margins) was preferred, followed by adjuvant radiotherapy or radiotherapy alone. The clinical characteristics, diagnosis, treatment and prognosis of EMP were analyzed. Results: The patients' symptoms were not specific, frequently with local obstruction symptom and localized masses. All patients were confirmed pathologically as suffering from monoclonal plasmacytoma, with negative bone marrow biopsy and negative skeletal survey. Five patients received surgery, 3 received radiotherapy, and 2 received surgery with additional radiation. The follow-up time was 16-125 months, with a median of 92 months. Two patients developed into multiple myeloma. One patient who received radiotherapy after surgery relapsed after 7 years of follow-up and again received surgical treatment, with no evidence of second recurrence. The remaining patients had no recurrence or progression. Conclusion: Extramedullary plasmacytoma of the head and neck has a good prognosis. Surgical treatment can be considered for completely resectable lesions.

68Ga-DOTA-DiPSMA PET/CT Imaging: Biodistribution, Dosimetry, and Preliminary Application in Prostate Cancer

Purpose: This prospective trial aimed to evaluate the safety, dosimetry, and biodistribution of a novel theranostic probe ⁶⁸Ga-DOTA-DiPSMA. Also, we have performed the first preliminary application with ⁶⁸Ga-DOTA-DiPSMA in prostate cancer (PCa) patients.

Methods: Five healthy volunteers and ten PCa patients were injected with an intravenous bolus of ⁶⁸Ga-DOTA-DiPSMA. They received serial whole-body PET scans from the time of injection up to 60 min post-injection, with a second PET/CT scanning at 120 min post-injection. In PCa patients, low-dose CT scan and whole-body PET were performed with 2 min per bed position in 40 min post-injection. Absorbed organ doses and effective doses were calculated using OLINDA/EXM. Normal organ uptake and tumor lesion uptake were measured. A lesion-by-lesion analysis was performed.

Results: ⁶⁸Ga-DOTA-DiPSMA administration was safe and well-tolerated. The kidneys received the highest absorbed dose (114.46 ± 29.28 μSv/MBq), followed by the urinary bladder wall (100.82 ± 46.22 μSv/MBq) in accordance with the expected Prostate-Specific Membrane Antigen (PSMA) renal excretion of the tracer. The mean effective dose was 19.46 ± 1.73 μSv/MBq. The SUV_max of ⁶⁸Ga-DOTA-DiPSMA PET/CT for PCa lesions, bone metastases, and lymph node metastases was 4.41 ± 2.72, 2.95 ± 1.11, and 3.26 ± 1.20, respectively.

Conclusion: Injection of ⁶⁸Ga-DOTA-DiPSMA is safe and associated with low absorbed and effective doses. ⁶⁸Ga-DOTA-DiPSMA shows favorable kinetics and imaging characteristics in patients who warrant further head-to-head comparison to validate ⁶⁸Ga-DOTA-DiPSMA as an alternative for gallium-68-labeled PSMA clinical PET. Low nonspecific uptake in normal organs of ⁶⁸Ga-DOTA-DiPSMA indicates potential radioligand therapy (RLT) application when labeled with ¹⁷⁷Lu, ⁹⁰Y, or ²²⁵Ac.

A prospective study on vulvovaginal candidiasis: multicentre molecular epidemiology of pathogenic yeasts in China

BACKGROUND

Vulvovaginal candidiasis (VVC) is frequent in women of reproductive age, but very limited data are available on the epidemiology in cases of VVC in China.

OBJECTIVES

The current study has been conducted to reveal the prevalence, species distribution of yeast causing VVC and molecular genetics of Candida albicans in China.

METHODS

Vaginal swabs were collected from 543 VVC outpatients recruited in 12 hospitals in China between September 2017 and March 2018. They were preliminarily incubated on Sabouraud dextrose agar and then positive subjects of which were then transmitted to our institute for further identification. CHROMagar™ was used to isolate Candida species, and all isolates were finally identified by DNA sequencing. Multilocus sequence typing (MLST) was used to analyse phylogenetic relationships of the various C. albicans isolates.

RESULTS

Eleven different yeast species were identified in 543 isolates, among which C. albicans (84.7%) was the most frequent, followed by C. glabrata (8.7%). We obtained 117 unique diploid sequence types from 451 clinical C. albicans isolates and 92 isolates (20.4%) belonged to a New Clade. All the strains appearing in the New Clade were from northern China and they were isolated from non-recurrent VVC.

CONCLUSIONS

Our findings suggest that C. albicans are still the main cause of VVC in China and the majority of C. albicans isolates belongs to Clade 1 with DST 79 and DST 45 being two most common. Moreover, the New Clade revealed in our study seems to be specific to northern China.

Evaluation of N, O-Benzamide difluoroboron derivatives as near-infrared fluorescent probes to detect β-amyloid and tau tangles

β-Amyloid (Aβ) plaques and Tau tangles are cognitive impairment markers vital for diagnosing and preventing Alzheimer's disease (AD). To systematically explore the relationship between the number or position of nitrogen atoms and their optical properties and biological properties, five series of new N, O-coordinated organo-difluoroboron probes were introduced as binding scaffolds for Aβ plaques and Tau tangles. These probes exhibited suitable optical properties for near-infrared (NIR) imaging. Probe 4PmNO-2 (4-((1E,3E)-4-(1,1-difluoro-1H-1λ⁴,9λ⁴-pyrimido[1,6-c][1,3,5,2]oxadiazaborinin-3-yl)buta-1,3-dien-1-yl)-N,N-dimethylaniline) displayed the excellent emission maximum (716 nm in PBS), a high quantum yield (61.4% in CH₂Cl₂), and a high affinity for synthetic Aβ_1-42 (K_d = 23.64 ± 1.08 nM) and Tau (K18) aggregates (K_d = 26.38 ± 1.29 nM), as well as for native Aβ plaques and NFTs in the brain tissue from AD patients. 4PmNO-2, with significantly enhanced fluorescence (Aβ_1-42, 136 fold; Tau (K18), 96 fold) and the highest initial brain uptake (11.57% ID/g at 2 min) in normal ICR mice, was evaluated further. In vivo NIR fluorescent imaging studies in living Aβ and Tau transgenic mice revealed that it could differentiate healthy and diseased animals. Further ex vivo fluorescent staining studies showed that 4PmNO-2 specifically bound to Aβ plaques and Tau tangles in transgenic mice. In summary, the probe 4PmNO-2 may be a useful near-infrared fluorescence (NIRF) probe for AD biomarkers.

PPA1 Promotes Breast Cancer Proliferation and Metastasis Through PI3K/AKT/GSK3β Signaling Pathway

Breast cancer is the most common malignancy among women. Inorganic pyrophosphatase 1 (PPA1) is a multifunctional protein involved in the development of several tumors. However, the role of PPA1 in breast cancer progression remains unclear. In this study, we found that PPA1 was highly expressed in breast cancer compared to its levels in normal breast tissue and that it was correlated with breast cancer clinicopathological characteristics, as well as poor survival in breast cancer patients. Silencing PPA1 restrained breast cancer proliferation and metastasis by regulating Slug-mediated epithelial-mesenchymal transition (EMT). Opposite results were observed following PPA1 overexpression. In addition, investigation of the underlying mechanism demonstrated that PPA1 ablation led to decrease phosphatidylinositol 3 kinase (PI3K) phosphorylation levels and attenuate phosphorylated AKT and glycogen synthase kinase-3 β (GSK3β), while ectopic PPA1 expression had the opposite effects. Moreover, PI3K inhibitors suppress the signaling pathways mediating the effects of PPA1 on breast cancer, resulting in tumor growth and metastasis suppression in vitro and in vivo. In summary, our results verify that PPA1 can act as an activator of PI3K/AKT/GSK3β/Slug-mediated breast cancer progression and that it is a potential therapeutic target for the inhibition of tumor progression.

P–129 Follicular extracellular vesicles of women with polycystic ovarian syndrome inhibit oocyte maturation

Study question

Does follicular extracellular vesicles of women with polycystic ovarian syndrome (PCOS-EVs) interfere with the quality of oocytes?

Summary answer

PCOS-EVs induced oxidative stress in the oocytes and inhibited oocyte maturation by increasing the abnormal mitochondria distribution and abnormal spindle rates.

What is known already

Polycystic ovarian syndrome (PCOS) is a common endocrine disorder in women of reproductive age, with a prevalence up to 10%. Women with PCOS are characterized by a clustering of features, including hyperandrogenism, polycystic ovarian morphology, and notably, anovulation. Although international guidelines recommend assisted reproduction techniques to be an effective resort for PCOS patients to conceive. However, even after overcoming ovulatory dysfunction via ovulation induction, the pregnancy outcomes of patients with PCOS were far from satisfying with lower fertilization, cleavage, and implantation rates, implicating that theoocyte quality of these patients are affected. Whereas the mechanisms have not been elucidated yet.

Study design, size, duration

Follicular fluid of PCOS patients (n = 10) and healthy controls (n = 10) were collected and used for extracellular vesicles (EVs) isolation via ultracentrifugation. Germinal vesicle (GV) oocytes collected from female ICR mice were cocultured with RIF-EVs or FER-EVs, respectively, and PBS served as a blank control. GV breakdown (GVBD) rate and maturation rate were calculated at two-hour and fourteen-hour of co-culture, respectively. Besides, oocyte mitochondria distribution, meiosis spindle morphology, and oxidative status were assessed in different groups.

Participants/materials, setting, methods

EVs were determined by western blotting, nanoparticle tracking analysis, and transmission electron microscopy. Fluorescence labeled EVs were used to visualize internalization by oocytes. Oocytes mitochondria and mitosis spindles were stained with fluorescence, and abnormal mitochondria rate or abnormal spindle rate was calculated. Reactive oxygen species (ROS) level was detected in the differently treated oocytes. Moreover, the expression of CAT, GSS, and SOD was determined in the oocytes using quantitative reverse transcription polymerase chain reaction.

Main results and the role of chance

Both PCOS-EVs and CTRL-EVs are bilayered vesicles, ranging from 100 to 150 nm, and enriched in Alix, TSG101, and CD9. EVs could be internalized by oocytes within one hour. After coculture, the GVBD rate was similar among the three groups; whereas the maturation rate was significantly decreased in the PCOS-EV group compared with CTRL-EV group or PBS group. In addition, the abnormal mitochondria distribution rate or abnormal spindle rate were significantly increased in the PCOS-EV group compared with PBS or CTRL-EV group. The ROS level was increased in the PCOS-EV group compared with CTRL-EV group, and the expression of CAT, GSS, and SOD was increased in the PCOS-EV-treated oocytes.

Limitations, reasons for caution

Our study did not identify the contents of PCOS-EVs and CTRL-EVs, and the molecular mechanisms of dysregulations induced by PCOS-EVs need further researches to investigate.

Wider implications of the findings: This work confirmed that EV-conducted cellular communication played an important role in oocyte development in women with PCOS. The dysregulation of oocytes induced by PCOS-EVs might be related to the poor oocyte quality of women with PCOS, which may provide a novel target to improve pregnancy outcomes of these patients.

Trial registration number

Not applicable

"Turn-On" Quinoline-Based Fluorescent Probe for Selective Imaging of Tau Aggregates in Alzheimer's Disease: Rational Design, Synthesis, and Molecular Docking

Tau aggregation is believed to have a strong association with the level of cognitive deficits in Alzheimer's disease (AD). Thus, optical brain imaging of tau aggregates has recently gained substantial attention as a promising tool for the early diagnosis of AD. However, selective imaging of tau aggregates is a major challenge due to sharing similar β-sheet structures with homologous Aβ fibrils. Herein, four quinoline-based fluorescent probes (Q-tau) were judiciously designed using the donor-acceptor architecture for selective imaging of tau aggregates. In particular, probe Q-tau 4 exhibited a strong intramolecular charge transfer and favorable photophysical profile, such as a large Stokes' shift and fluorescence emission wavelength of 630 nm in the presence of tau aggregates. The probe also displayed a "turn-on" fluorescence behavior toward tau fibrils with a 3.5-fold selectivity versus Aβ fibrils. In addition, Q-tau 4 exhibited nanomolar binding affinity to tau aggregates (K_d = 16.6 nM), which was 1.4 times higher than that for Aβ fibrils. The mechanism of "turn-on" fluorescence was proposed to be an environment-sensitive molecular rotor-like response. Moreover, ex vivo labeling of human AD brain sections demonstrated favorable colocalization of Q-tau 4 and the phosphorylated tau antibody, while comparable limited staining was observed with Aβ fibrils. Molecular docking was conducted to obtain insights into the tau-binding mode of the probe. Collectively, Q-tau 4 has successfully been used as a tau-specific fluorescent imaging agent with lower background interference.

Visualizing Tumors in Real Time: A Highly Sensitive PSMA Probe for NIR-II Imaging and Intraoperative Tumor Resection

Owing to the complex anatomical structure, precise resection of a tumor while maintaining adjacent tissue is a challenge in radical prostatectomy for prostate cancer (PCa). Optical imaging in near-infrared window II (NIR-II) is a promising technology for intraoperative guidance, whereas there is no available probe for PCa yet. In this article, a novel probe (PSMA-1092) bearing two prostate-specific membrane antigen (PSMA) binding motifs was developed, displaying excellent optical properties (λ_max = 1092 nm) and ultrahigh affinity (K_i = 80 pM) toward PSMA. The tumor was visualized with high resolution (tissue-to-normal tissue ratio = 7.62 ± 1.05) and clear margin by NIR-II imaging using PSMA-1092 in a mouse model. During the tumor resection, residual tumors missed by visible inspection were detected by the real-time imaging. Overall, PSMA-1092 displayed excellent performance in delineating the tumor margin and detecting residual tumors, demonstrating promising potential for precise PCa tumor resection in clinical practice.

Synthesis, Preclinical Evaluation, and First-in-Human PET Study of Quinoline-Containing PSMA Tracers with Decreased Renal Excretion

The prostate-specific membrane antigen (PSMA) is considered to be an excellent theranostic target of prostate cancer (PCa). In this study, three 18F-labeled PSMA tracers with a more lipophilic quinoline functional spacer were designed, synthesized, and evaluated based on the Glu-Ureido-Lys binding motif. The effect of structure-related lipophilic difference on distribution and excretion of these tracers in vitro and in vivo (cells, rodent, primate, and human) was investigated by comparing with [18F]DCFPyL. There is no significant correlation between the renal elimination and the lipophilicity of the tracers in all species. However, the higher the lipophilicity of tracer, the higher the radioactivity accumulation in the liver of primate and human, and the less radioactivity is to excrete to the bladder with urine. The screened tracer [18F]8c, with a Ki value of 4.58 nM, displayed notable low bladder retention and demonstrated good imaging properties in patients with PCa.

Effect of lncRNA AK023948 on rats with postmenopausal osteoporosis via PI3K/AKT signaling pathway

OBJECTIVE

To investigate the effect of long non-coding ribonucleic acid (lncRNA) AK023948 (AK0) on rats with postmenopausal osteoporosis via the phosphoinositide 3-kinase/protein kinase B (PI3K/AKT) signaling pathway.

MATERIALS AND METHODS

Firstly, postmenopausal osteoporosis rat models were established to obtain osteoblasts. The phosphorylation level of AKT was analyzed by controlling the expression of AK0 gene in osteoblasts. Finally, XTT was used to analyze the proliferation of osteoblasts and the messenger ribonucleic acid (mRNA) expression level of caspase in AK0 gene knockout (KO) rat model.

RESULTS

In the bone tissue of postmenopausal osteoporosis rats, the levels of phospho-PI3K (p-PI3K), p-Akt, and p-phosphoinositide-dependent kinase-1(PDK1) were significantly decreased (p<0.05). In rat model osteoblasts, the overexpression of AK0 gene upregulated the phosphorylation level of AKT, while the interference with small interfering RNA (siRNA) in AK0 gene decreased that of AKT. Knocking out AK0 gene led to the down-regulation of phosphorylation level of AKT in cells. Moreover, if the AK0 gene was re-expressed in the KO rat model cells, the phosphorylation level of AKT was restored to a certain extent, but still lower than that after the overexpression of AK0 gene. Although the proliferation rate of osteoblasts in estrogen deficiency-related osteoporosis rats was low, the growth rate of osteoblasts with AK0 KO was remarkably lower than that in blank control group (p<0.05). It was also found that there was a certain correlation between AK0 gene and osteoblast apoptosis.

CONCLUSIONS

LncRNA AK0 can regulate the phosphorylation level of AKT in osteoblasts of rats with estrogen deficiency-related osteoporosis through the PI3K/AKT signaling pathway, thus regulating the proliferation of osteoblasts. It is speculated that lncRNA AK0 may be an important factor in regulating the PI3K/AKT signaling pathway.

Effect of lncRNA AK125437 on postmenopausal osteoporosis rats via MAPK pathway

OBJECTIVE

The aim of this study was to explore the effect of long non-coding ribonucleic acid (lncRNA) AK125437 on rats with postmenopausal osteoporosis via the mitogen-activated protein kinase (MAPK) pathway.

MATERIALS AND METHODS

A total of 36 Sprague-Dawley rats were randomly divided into three groups, including normal group, model group, and an inhibitor group, with 12 rats in each group. Only ovaries were exposed in normal group. The postmenopausal osteoporosis model was established in model group. Meanwhile, the intervention was performed with inhibitor for 3 months after modeling in inhibitor group, followed by sampling. The expression of receptor activator of nuclear factor kappa-B ligand (RANKL) was detected via immunohistochemistry. The protein expression level of phosphorylated p38 (p-p38) MAPK was determined via Western blotting (WB). Furthermore, the expression level of lncRNA AK125437 and the content of serum estradiol were determined via quantitative Polymerase Chain Reaction (qPCR) and enzyme-linked immunosorbent assay (ELISA), respectively. In addition, bone mineral density was measured using dual-energy X-ray bone mineral absorptiometer.

RESULTS

Immunohistochemistry results indicated that model group and inhibitor group had notably up-regulated positive expression level of RANKL than normal group (p<0.05), which was remarkably lower in inhibitor group than model group (p<0.05). Western blot results showed that compared with normal group, the protein expression level of p-p38 MAPK was substantially elevated in model and inhibitor groups (p<0.05). Meanwhile, the protein expression level of p-p38 MAPK was markedly lower in inhibitor group than that in model group (p<0.05). According to qPCR results, the expression level of lncRNA AK125437 was significantly up-regulated in both model group and inhibitor group compared with normal group, showing statistically significant differences (p<0.05). However, no significant differences were observed between model group and inhibitor group (p>0.05). ELISA results revealed that model group and inhibitor group had markedly lower estradiol content than normal group (p<0.05). There was no statistically significant difference in the content of estradiol between the two groups (p>0.05). According to the measurement results of bone mineral density, compared with normal group, bone mineral density was notably lower in model group and inhibitor group (p<0.05). Furthermore, it was markedly higher in inhibitor group than that of model group (p<0.05).

CONCLUSIONS

LncRNA AK125437 affects the bone mineral density of rats with postmenopausal osteoporosis by activating the MAPK pathway.

Synthesis and Evaluation of Fluorine-18 Labeled 2-Phenylquinoxaline Derivatives as Potential Tau Imaging Agents

In this study, three pairs of optically pure ¹⁸F-labeled 2-phenylquinoxaline derivatives were evaluated as Tau imaging agents for the diagnosis of Alzheimer's disease (AD). The chiral 2-fluoromethyl-1,2-ethylenediol side chain was attached to the 2-phenylquinoxaline backbone to increase hydrophilicity, thereby improving the binding affinity of the probe to tangles and their selectivity toward Tau tangles over β-amyloid plaques (Aβ). These probes displayed excellent fluorescent properties and high selectivity for tangles on brain sections from transgenic mice (rTg4510) and AD patients. Quantitative binding assays with AD homogenates showed that the probes (R)-5 and (S)-16 have a high affinity (K_i = 4.1 and 10.3 nM, respectively) and high selectivity (30.5-fold and 34.6-fold, respectively) for tangles over Aβ. The high affinity and selectivity of (R)-[¹⁸F]5 and (S)-[¹⁸F]16 for tangles were further confirmed with autoradiography on AD brain tissue in vitro. In addition, they displayed sufficient blood-brain barrier penetration (7.06% and 10.95% ID/g, respectively) and suitable brain kinetics (brain_2 min/brain_60 min = 10.1, 6.5 respectively) in normal mice. Ex vivo metabolism studies and micro-positron emission computed tomography (PET) revealed high brain biostability, good brain kinetic properties, and low nonspecific binding for (S)-[¹⁸F]16. Together, these results demonstrate that (R)-[¹⁸F]5 and (S)-[¹⁸F]16 are promising PET probes for Tau tangles imaging.

Near-Infrared Fluorescent Probes with Rotatable Polyacetylene Chains for the Detection of Amyloid-β Plaques

The plaques of accumulated β-amyloid (Aβ) in the parenchymal brain are accepted as an important biomarker for the early diagnosis of Alzheimer's disease (AD). Many near-infrared (NIR) probes, which were based on the D-π-A structure and bridged by conjugated double bonds, had been reported and displayed a high affinity to Aβ plaques. Considering the isomerization caused by the polyethylene chain, however, the conjugated polyacetylene chain is a better choice for developing new NIR Aβ probes. Hence, in this report, a new series of NIR probes with naphthyl or phenyl rings and different numbers of conjugated triple bonds were designed, synthesized, and evaluated as NIR probes for Aβ plaques. Upon interaction with Aβ aggregates, these probes displayed a significant increase in fluorescence intensity (45- to 360-fold) and a high to moderate affinity (6.05-56.62 nM). Among them, probe 22b displayed excellent fluorescent properties with a 183-fold increase in fluorescence intensity and an emission maximum at 650 nm after incubated with Aβ aggregates. Furthermore, 22b had a high affinity to Aβ aggregates (K_d = 12.96 nM) and could efficiently detect the Aβ plaques in brain sections from both transgenic mice and AD patients in vitro. In summary, this work may lead to a new direction in the development of novel NIR probes for the detection of Aβ plaques.

18F-labeled 2-phenylbenzoheterocycles with chiral dihydroxyl side chains as β-amyloid imaging probes

This study reported the design, synthesis and bio-evaluation of 2-phenylbenzoheterocycles with chiral dihydroxyl side chains as β-amyloid (Aβ) imaging probes. This strategy of introducing two hydroxyls offered a simplified method for effectively reducing the lipophilicity. The probes (R, S)/(S, R)-14-15 with benzothiazole scaffold displayed good binding affinities toward Aβ_1-42 aggregates with K_i values ranging from 47.63 to 56.28 nM. Further biological studies shown that (R, S)/(S, R)-[¹⁸F]14 have no obvious chirality-related discrepancy in binding ability and mice bio-distribution, while (S, R)-enantiomer exhibited slightly faster brain washout rate than (R, S)-enantiomer. Compared to the FDA approved [¹⁸F]Florbetapir and the fluoro-peglated 2-phenylbenzothiazole derivatives, (S, R)-[¹⁸F]14 displayed improved brain kinetics (6.40% ID/g at 2 min, brain_{2 min}/brain_{60 min} = 7.80) that is favorable for further application. In vitro autoradiography studies validated its high affinity and specificity to Aβ plaques. Overall, (S, R)-[¹⁸F]14 deserved further detailed study as a potential PET imaging probe for AD early diagnosis.

MiRNA-98-5p inhibits the progression of osteosarcoma by regulating cell cycle via targeting CDC25A expression

OBJECTIVE

The aim of this study was to elucidate the exact role of microRNA-98-5p (miRNA-98-5p) in the progression of osteosarcoma and to explore its potential mechanism.

PATIENTS AND METHODS

The expression levels of miRNA-98-5p and cell division cycle 25 (CDC25A) in osteosarcoma tissues and cell lines were determined by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). Meanwhile, the correlation between expressions of miRNA-98-5p and CDC25A and the survival of osteosarcoma patients was analyzed. After altering miRNA-98-5p and CDC25A expressions by liposome transfection, the expression levels of CDC25A, ki67, Cyclin D1, p21, BCL2-Associated X (BAX), B-cell lymphoma-2 (BCL-2) and BCL-XL in osteosarcoma cells were detected. Subsequently, potential binding sites between miRNA-98-5p and CDC25A were predicted and further verified by miRanda and Dual-Luciferase reporter gene assay, respectively. Regulatory effects of miRNA-98-5p and CDC25A on the migratory ability of osteosarcoma cells were evaluated by transwell assay. Moreover, nude mice were subcutaneously implanted with MG-63 cells over-expressing miRNA-98-5p or negative control. In addition, the functions of miRNA-98-5p and CDC25A in tumor-bearing nude mice were explored in vivo.

RESULTS

MiRNA-98-5p was lowly expressed in osteosarcoma tissues and cell lines, whereas CDC25A was highly expressed. Survival analysis showed that the survival of osteosarcoma patients with low-level of miRNA-98-5p or high-level of CDC25A was significantly worse. Besides, a negative correlation was identified between miRNA-98-5p and CDC25A. Subsequent experiments revealed that miRNA-98-5p significantly inhibited cell cycle progression and migratory potential, whereas induced the apoptosis of osteosarcoma cells by down-regulating CDC25A.

CONCLUSIONS

MiRNA-98-5p is lowly expressed, while CDC25A is highly expressed in osteosarcoma. Furthermore, miRNA-98-5p regulates cell cycle progression by down-regulating CDC25A, thus inhibiting the progression of osteosarcoma.

Discovery of Diphenoxy Derivatives with Flexible Linkers as Ligands for β-Amyloid Plaques

The highly rigid and planar scaffolds with π-conjugated systems have been widely considered to be indispensable for β-amyloid (Aβ) binding ligands. In this study, a library of diphenoxy compounds with different types of more flexible linkers as Aβ ligands were synthesized and evaluated. Most of them displayed good affinity (K_i < 100 nM) for Aβ_1-42 aggregates, and some ligands even showed values of K_i less than 10 nM. Structure-activity relationship analysis revealed that modification on the linkers or substituents tolerated great flexibility, which challenged the long-held belief that rigid and planar structures are exclusively favored for Aβ binding. Three ligands were labeled by iodine-125, and they exhibited good properties in vitro and in vivo, which further supported that this flexible scaffold was potential and promising for the development of Aβ imaging agents.

Effect of age and parity on maternal diastolic function in middle trimester pregnant women with normal left ventricular ejection fraction and potential link of diastolic function to pre-eclampsia

Background

It has been suggested that maternal cardiac adaptations during pregnancy differ between nulliparous and multipara women and also vary according to the age. Impaired cardiac function precedes pre-eclampsia.

Purpose

To evaluate effect of age and parity on maternal cardiac diastolic function in middle trimester among pregnant women with normal left ventricular ejection fraction as well as correlation between impaired diastolic function and pre-eclampsia.

Methods

Pregnant women with singleton pregnancies carried from 13 weeks to 20 weeks and left ventricular ejection fraction (LVEF) ≥50% were identified. Diastolic function parameters were assessed using transthoracic echocardiography. Pre-eclampsia was identified from medical records.

Results

376 pregnant women were included (median age: 30 years; median gestational age: 14 weeks; 171 multiparous women). LVEF was 66%. Impaired cardiac diastolic function was seen in 7.8% of pregnant women &lt;35 years compared with 28.6% of those ≥35 years (p=0.000). ROC curve showed women with maternal age over 32 began to have a higher rate of impaired cardiac diastolic function (AUC=0.704, p=0.000, sensitivity=54.5%, specificity=75.3%). There was no difference in diastolic function indices between maternal women grouped by parity. After adjustment for confounders, maternal age can be independent effect factor of Em declined (P&lt;0.05). Em&lt;13cm/s was significantly associated with pre-eclampsia occurrence (HR 8.56; 95% CI: 3.40–21.57) after adjusting for the confounders.

Conclusion

Maternal age is an independent impact factor for diastolic function decline. There is no difference in cardiac diastolic function between nullipara and multipara. Pre-eclampsia occurrence is significantly higher in patients with diastolic function decline at mid-gestation. The utility of risk stratification using diastolic function at mid-gestation may improve the survival outcomes of pregnant women.

Association between Em and PE risk

Funding Acknowledgement

Type of funding source: None

Immunocyte density in parathyroid carcinoma is correlated with disease relapse

PURPOSE

Parathyroid carcinoma (PC) is an endocrine malignancy with a poor prognosis. The tumour immune microenvironment is a critical factor influencing the outcomes of multiple cancer types. However, knowledge of the immune microenvironment in PC remains limited.

METHODS

The intratumoural density of immunocytes and the Ki-67 index were evaluated immunohistochemically in 51 PC patient samples and were compared with clinicopathological features and parafibromin staining results. The Kaplan-Meier method and Cox proportional hazards analysis were used to estimate the effects of these variables on clinical outcomes.

RESULTS

Intratumoural immunocyte density was not correlated with age, gender, urolithiasis, or palpation of a neck mass. The Ki-67 index was correlated with the intratumoural density of CD3⁺ cells (P = 0.022) and CD8⁺ cells (P = 0.021) and serum calcium levels (P = 0.022). In the intratumoural area of primary foci, Kaplan-Meier method showed that the risk factors associated with recurrence/metastasis were a low density of CD3⁺ (P = 0.017), CD8⁺ (P = 0.019) and CD45⁺ cells (P = 0.047), a high density of CD163⁺ cells (P = 0.003) and a high Ki-67 index (P = 0.004). Cox regression multivariate analysis revealed that CD163⁺ cell density (hazard ratio (HR) 16.19, 95% confidence interval (CI) 1.99-131.66; P = 0.009) and CD8⁺ cell density (HR 0.13, 95% CI 0.02-0.76, P = 0.024) were independent factors associated with PC relapse.

CONCLUSION

The immune microenvironment is an important factor influencing the relapse of PC. The intratumoural density of CD3⁺, CD8⁺, CD45⁺, and CD163⁺ immunocytes was correlated with disease-free survival (DFS) in patients with PC. Immunotherapy based on T lymphocytes or tumour-associated macrophages may be a promising treatment strategy.

Cosmic-ray antinuclei as messengers of new physics: status and outlook for the new decade

The precise measurement of cosmic-ray antinuclei serves as an important means for identifying the nature of dark matter and other new astrophysical phenomena, and could be used with other cosmic-ray species to understand cosmic-ray production and propagation in the Galaxy. For instance, low-energy antideuterons would provide a "smoking gun" signature of dark matter annihilation or decay, essentially free of astrophysical background. Studies in recent years have emphasized that models for cosmic-ray antideuterons must be considered together with the abundant cosmic antiprotons and any potential observation of antihelium. Therefore, a second dedicated Antideuteron Workshop was organized at UCLA in March 2019, bringing together a community of theorists and experimentalists to review the status of current observations of cosmic-ray antinuclei, the theoretical work towards understanding these signatures, and the potential of upcoming measurements to illuminate ongoing controversies. This review aims to synthesize this recent work and present implications for the upcoming decade of antinuclei observations and searches. This includes discussion of a possible dark matter signature in the AMS-02 antiproton spectrum, the most recent limits from BESS Polar-II on the cosmic antideuteron flux, and reports of candidate antihelium events by AMS-02; recent collider and cosmic-ray measurements relevant for antinuclei production models; the state of cosmic-ray transport models in light of AMS-02 and Voyager data; and the prospects for upcoming experiments, such as GAPS. This provides a roadmap for progress on cosmic antinuclei signatures of dark matter in the coming years.

N,O-Benzamide difluoroboron complexes as near-infrared probes for the detection of β-amyloid and tau fibrils

In this study, a series of organo difluoroboron probes with a BF2 benzamide moiety was designed, prepared and evaluated. Among them, 2c displayed the best optical and biological properties, and may be used as a useful near-infrared fluorescent probe for the detection of Aβ plaques and neurofibrillary tangles in AD.

Clinicopathologic features and prognosis of synchronous and metachronous multiple primary colorectal cancer

PURPOSE

Multiple primary colorectal cancers (MPCCs) are different from solitary colorectal cancers in many aspects, which are not well studied. The aim of this study was to clarify the clinicopathological features and prognosis of MPCCs.

METHODS

The data of 64 patients with MPCCs out of 2300 patients with colorectal cancers (CRCs) from January 2009 to December 2017 were retrospectively analyzed. Stratified analysis was conducted based on subtypes and microsatellite status.

RESULTS

The overall incidence of MPCC was 2.8% and the median follow-up duration was 51.5 (range 1-120) months. Metachronous CRCs (MCRCs) are more likely to appear in the right colon (p < 0.05). However, no significant differences regarding age, sex, BMI, tumor size, smoking/drinking history, TNM stage, family history of cancer, and 5-year survival rate were observed between synchronous CRC (SCRC) and MCRC. Advanced TNM stage (III) and the presence of polyps were found to be independent poor prognostic factors for MPCCs. The prevalence of mismatch repair deficiency (dMMR) in MPCCs was 28.1%. Deficient MMR is more likely to appear in younger, lighter MPCC patients with polyps (p < 0.05). Of four mismatch repair proteins, MLH-1, MSH-2, MSH-6, and PMS-2 were negative in nine, nine, five, and nine patients, respectively. The 5-year survival rate did not differ significantly between MMR-proficient (pMMR) and dMMR groups (p = 0.752).

CONCLUSIONS

Synchronous CRC (SCRC) and MCRC might represent similar disease entities with different courses. Deficient MMR is more likely to appear in younger, lighter MPCC patients with polyps and it is an essential indicator for screening Lynch syndrome.