Intense 18F-FAPI Uptake in Small Recurrent Lesions of Combined Hepatocellular-Cholangiocarcinoma Negative on 18F-FDG PET/CT.

ABSTRACT: A 70-year-old man presented with combined hepatocellular-cholangiocarcinoma underwent partial hepatectomy and chemoradiotherapy approximately 3 months ago. Follow-up abdominal ultrasound detected a new small lesion with decreased echogenicity in the hepatic segment I, potentially indicating recurrence. The patient was enrolled in a clinical trial of comparison of 18F-FDG and 18F-FAPI PET/CT in hepatic lesions. Compared with non-18F-FDG avidity, 18F-FAPI PET/CT showed intense tracer uptake of the hepatic lesion. Resection of the lesion was subsequently performed, and pathologic analysis confirmed the diagnosis of recurrent combined hepatocellular-cholangiocarcinoma.

Head-to-head comparison between [68Ga]Ga-DOTA-NOC and [18F]DOPA PET/CT in a diverse cohort of patients with pheochromocytomas and paragangliomas.

PURPOSE: To compare the detection ability of 68Ga-labelled DOTA-l-Nal3-octreotide ([68Ga]Ga-DOTA-NOC) and 6-[18F]fluoro-L-3,4-dihydroxyphenylalanine ([18F]DOPA) in patients with phaeochromocytomas and paragangliomas (PPGLs) of different origins and gene mutations, such as germline succinate dehydrogenase complex genes (SDHx). METHODS: Eighty-five patients with histopathologically confirmed PPGLs who underwent both [68Ga]Ga-DOTA-NOC and [18F]DOPA PET/CT from March 2017 to June 2023 were enrolled in this retrospective study. For comparative analyses, PPGLs were classified as phaeochromocytoma (PCC), sympathetic paraganglioma (sPGL), and head/neck paraganglioma (HNPGL). Detection rates were analyzed on per-patient and per-lesion bases and compared using the Chi-square/Fischer's exact test. RESULTS: Among 85 patients with PPGLs (48 males; 43 years ± 17 [SD]), the patient-based detection rates of [68Ga]Ga-DOTA-NOC and [18F]DOPA PET/CT were 87.1% (74/85) and 89.4% (76/85), respectively (p = 0.634), and the lesion-based detection rates were 80.8% (479/593) and 71.2% (422/593), respectively (p < 0.001). Only one patient with a recurrent PCC presented double-negative imaging, while 66 patients exhibited double-positive imaging. The remaining patients were either [68Ga]Ga-DOTA-NOC-negative/[18F]DOPA-positive (n = 10) or [68Ga]Ga-DOTA-NOC-positive/[18F]DOPA-negative (n = 8). In subgroup analyses, [68Ga]Ga-DOTA-NOC PET/CT detected significantly more metastases of sPGL (91.1%, 236/259) and SDHx-related PPGL (89.6%, 86/96) than [18F]DOPA PET/CT (48.6%[126/259] and 50.0%[48/96], respectively; both p < 0.001). However, [18F]DOPA showed significantly higher detection rates of PCC in both primary/recurrent and metastatic lesions (94.3%[50/53] vs. 62.3%[33/53] and 87.9%[174/198] vs. 69.2%[137/198], respectively; both p < 0.001). Regarding metastases in different organs, [68Ga]Ga-DOTA-NOC PET/CT detected more lesions than [18F]DOPA PET/CT in bone (96.2%[176/183] vs. 66.1%[121/183]; p < 0.001) and lymph nodes (82.0%[73/89] vs. 53.9%[48/89]; p < 0.001) but less lesions in peritoneum (20%[4/20] vs. 100%[20/20]; p < 0.001). CONCLUSION: [68Ga]Ga-DOTA-NOC and [18F]DOPA are complementary in diagnosing PPGL under the appropriate clinical setting. [68Ga]Ga-DOTA-NOC should be considered as the ideal first-line tracer for detecting metastases of sPGL and SDHx-related tumours, whereas [18F]DOPA may be the optimal tracer for evaluating non-SDHx-related PCC, especially in detecting primary lesions and monitoring recurrence.

Genome-Resolved Metagenomics and Denitrifying Strain Isolation Reveal New Insights into Microbial Denitrification in the Deep Vadose Zone.

The heavy use of nitrogen fertilizer in intensive agricultural areas often leads to nitrate accumulation in subsurface soil and nitrate contamination in groundwater, which poses a serious risk to public health. Denitrifying microorganisms in the subsoil convert nitrate to gaseous forms of nitrogen, thereby mitigating the leaching of nitrate into groundwater. Here, we investigated denitrifying microorganisms in the deep vadose zone of a typical intensive agricultural area in China through microcosm enrichment, genome-resolved metagenomic analysis, and denitrifying bacteria isolation. A total of 1000 metagenome-assembled genomes (MAGs) were reconstructed, resulting in 98 high-quality, dereplicated MAGs that contained denitrification genes. Among them, 32 MAGs could not be taxonomically classified at the genus or species level, indicating that a broader spectrum of taxonomic groups is involved in subsoil denitrification than previously recognized. A denitrifier isolate library was constructed by using a strategy combining high-throughput and conventional cultivation techniques. Assessment of the denitrification characteristics of both the MAGs and isolates demonstrated the dominance of truncated denitrification. Functional screening revealed the highest denitrification activity in two complete denitrifiers belonging to the genus Pseudomonas. These findings greatly expand the current knowledge of the composition and function of denitrifying microorganisms in subsoils. The constructed isolate library provided the first pool of subsoil-denitrifying microorganisms that could facilitate the development of microbe-based technologies for nitrate attenuation in groundwater.

Acute Macular Neuroretinopathy after SARS-CoV-2 Infection: An Analysis of Clinical and Multimodal Imaging Characteristics.

BACKGROUND: This study aimed to analyze clinical and multimodal imaging characteristics of acute macular neuroretinopathy (AMN) post-recent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. METHODS: Retrospective observational study. Medical records and multimodal imaging of 12 AMN eyes of eight patients (six female and two male) with recent SARS-CoV-2 infection were retrospectively analyzed. RESULTS: Four patients (50%) presented with bilateral AMN. Fundus ophthalmoscopy revealed a reddish-brown lesion around the macula, and two eyes had cotton-wool spots at the posterior pole. Three eyes showed mild hypo-autofluorescence. All FFA images (7 eyes) showed no abnormal signs. On OCT scans, all eyes showed outer nuclear layer (ONL) thinning, 8 eyes (66.7%) showed ONL hyperreflectivity, 5 eyes (41.7%) showed outer plexiform layer (OPL) hyperreflectivity, 8 eyes (66.7%) showed interdigitation zone (IZ) disruption, 11 eyes (91.6%) showed ellipsoid zone (EZ) disruption, 2 eyes (16.7%) showed cotton-wool spots and inner plexiform layer (IPL) hyperreflectivity, 1 eye (8.3%) had intraretinal cyst and 1 eye (8.3%) had inner nuclear layer (INL) thinning. Persistent scotoma, ONL hyperreflectivity and IZ/EZ disruption as well as recovery of OPL hyperreflectivity were reported after follow-up in three cases. CONCLUSIONS: AMN post-SARS-CoV-2 mostly affected young females and could present unilaterally or bilaterally. Dark lesions on IR reflectance and outer retinal hyperreflectivity on OCT are useful in diagnosing AMN. OPL/ONL hyperreflectivity on OCT could disappear after follow-up, but ONL thinning and IZ/EZ could persist.

[Network Meta-analysis of efficacy of seven Chinese patent medicines in treatment of inflammatory response in chronic glomerulonephritis].

This study aimed to evaluate the efficacy and safety of various Chinese patent medicines in the treatment of inflammatory response in chronic glomerulonephritis(CGN) based on network Meta-analysis. Randomized controlled trial(RCT) of oral Chinese patent medicines for improving inflammatory response in patients with CGN was retrieved from databases such as CNKI, Wanfang, VIP, SinoMed, PubMed, Cochrane Library, EMbase, and Web of Science from database inception to March 2023. All investigators independently screened the literature, extracted data, and evaluated the quality. Stata 16.0 and RevMan 5.4.1 software were used to analyze the data of the literature that met the quality standards. Finally, 71 RCTs were included, involving 7 Chinese patent medicines. The total sample size was 6 880 cases, including 3 441 cases in the test group and 3 439 cases in the control group. The network Meta-analysis showed that(1) in terms of reducing TNF-α, the top 3 optimal interventions according to the surface under the cumulative ranking curve(SUCRA) were Shenyanshu Capsules/Granules/Tablets+conventional western medicine, Huangkui Capsules+conventional western medicine, and Bailing Capsules+conventional western medicine.(2) In terms of reducing hs-CRP, the top 3 optimal interventions according to SUCRA were Yishen Huashi Granules+conventional western medicine, Huangkui Capsules+conventional wes-tern medicine, and Bailing Capsules+conventional western medicine.(3) In terms of reducing IL-6, the top 3 optimal interventions according to SUCRA were Yishen Huashi Granules+conventional western medicine, Bailing Capsules+conventional western medicine, and Shenyan Kangfu Tablets+conventional western medicine.(4) In terms of reducing 24hUTP, the top 3 optimal interventions according to SUCRA were Shenyan Kangfu Tablets+conventional western medicine, Bailing Capsules+conventional western medicine, and Huangkui Capsules+conventional western medicine.(5) In terms of reducing Scr, the top 3 optimal interventions according to SUCRA were Bailing Capsules+conventional western medicine, Shenyanshu Capsules/Granules/Tablets+conventional western medicine, and Yishen Huashi Granules+conventional western medicine.(6) In terms of reducing BUN, the top 3 optimal interventions according to SUCRA were Yishen Huashi Granules+conventional western medicine, Shenyanshu Capsules/Granules/Tablets+conventional western medicine, and Bailing Capsules+conventional western medicine.(7) In terms of improving the clinical total effective rate, the top 3 optimal interventions according to SUCRA were Huangkui Capsules+conventional western medicine, Kunxian Capsules+conventional western medicine, and Yishen Huashi Granules+conventional western medicine. The results showed that the combination of conventional western medicine and Chinese patent medicine could reduce the expression of serum inflammatory factors TNF-α, hs-CRP, and IL-6 and inhibit the inflammatory response. The combination of conventional western medicine and Chinese patent medicine was superior to conventional western medicine alone in reducing Scr, BUN, and 24hUTP, and improving the clinical total effective rate of treatment. Due to the limitation of the quantity and quality of literature included, the above conclusions need to be validated by more high-quality studies.

Liver macrophages and sinusoidal endothelial cells execute vaccine-elicited capture of invasive bacteria.

Vaccination has substantially reduced the morbidity and mortality of bacterial diseases, but mechanisms of vaccine-elicited pathogen clearance remain largely undefined. We report that vaccine-elicited immunity against invasive bacteria mainly operates in the liver. In contrast to the current paradigm that migrating phagocytes execute vaccine-elicited immunity against blood-borne pathogens, we found that invasive bacteria are captured and killed in the liver of vaccinated host via various immune mechanisms that depend on the protective potency of the vaccine. Vaccines with relatively lower degrees of protection only activated liver-resident macrophage Kupffer cells (KCs) by inducing pathogen-binding immunoglobulin M (IgM) or low amounts of IgG. IgG-coated pathogens were directly captured by KCs via multiple IgG receptors FcγRs, whereas IgM-opsonized bacteria were indirectly bound to KCs via complement receptors of immunoglobulin superfamily (CRIg) and complement receptor 3 (CR3) after complement C3 activation at the bacterial surface. Conversely, the more potent vaccines engaged both KCs and liver sinusoidal endothelial cells by inducing higher titers of functional IgG antibodies. Endothelial cells (ECs) captured densely IgG-opsonized pathogens by the low-affinity IgG receptor FcγRIIB in a "zipper-like" manner and achieved bacterial killing predominantly in the extracellular milieu via an undefined mechanism. KC- and endothelial cell-based capture of antibody-opsonized bacteria also occurred in FcγR-humanized mice. These vaccine protection mechanisms in the liver not only provide a comprehensive explanation for vaccine-/antibody-boosted immunity against invasive bacteria but also may serve as in vivo functional readouts of vaccine efficacy.

Dissecting the intricacies of human antibody responses to SARS-CoV-1 and SARS-CoV-2 infection.

The 2003 severe acute respiratory syndrome coronavirus (SARS-CoV-1) causes more severe disease than SARS-CoV-2, which is responsible for COVID-19. However, our understanding of antibody response to SARS-CoV-1 infection remains incomplete. Herein, we studied the antibody responses in 25 SARS-CoV-1 convalescent patients. Plasma neutralization was higher and lasted longer in SARS-CoV-1 patients than in severe SARS-CoV-2 patients. Among 77 monoclonal antibodies (mAbs) isolated, 60 targeted the receptor-binding domain (RBD) and formed 7 groups (RBD-1 to RBD-7) based on their distinct binding and structural profiles. Notably, RBD-7 antibodies bound to a unique RBD region interfaced with the N-terminal domain of the neighboring protomer (NTD proximal) and were more prevalent in SARS-CoV-1 patients. Broadly neutralizing antibodies for SARS-CoV-1, SARS-CoV-2, and bat and pangolin coronaviruses were also identified. These results provide further insights into the antibody response to SARS-CoV-1 and inform the design of more effective strategies against diverse human and animal coronaviruses.

Head-to-head comparison of 18F-FAPI and 18F-FDG PET/CT in staging and therapeutic management of hepatocellular carcinoma.

BACKGROUND: Fluorine 18 (18F) fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) has limitations in staging hepatocellular carcinoma (HCC). The recently introduced 18F-labeled fibroblast-activation protein inhibitor (FAPI) has shown promising prospects in detection of HCC lesions. This study aimed to investigate the initial staging and restaging performance of 18F-FAPI PET/CT compared to 18F-FDG PET/CT in HCC. METHODS: This prospective study enrolled histologically confirmed HCC patients from March 2021 to September 2022. All patients were examined with 18F-FDG PET/CT and 18F-FAPI PET/CT within 1 week. The maximum standard uptake value (SUVmax), tumor-to-background ratio (TBR), and diagnostic accuracy were compared between the two modalities. RESULTS: A total of 67 patients (57 men; median age, 57 [range, 32-83] years old) were included. 18F-FAPI PET showed higher SUVmax and TBR values than 18F-FDG PET in the intrahepatic lesions (SUVmax: 6.7 vs. 4.3, P < 0.0001; TBR: 3.9 vs. 1.7, P < 0.0001). In diagnostic performance, 18F-FAPI PET/CT had higher detection rate than 18F-FDG PET/CT in intrahepatic lesions [92.2% (238/258) vs 41.1% (106/258), P < 0.0001] and lymph node metastases [97.9% (126/129) vs 89.1% (115/129), P = 0.01], comparable in distant metastases [63.6% (42/66) vs 69.7% (46/66), P > 0.05]. 18F-FAPI PET/CT detected primary tumors in 16 patients with negative 18F-FDG, upgraded T-stages in 12 patients and identified 4 true positive findings for local recurrence than 18F-FDG PET, leading to planning therapy changes in 47.8% (32/67) of patients. CONCLUSIONS: 18F-FAPI PET/CT identified more primary lesions, lymph node metastases than 18F-FDG PET/CT in HCC, which is helpful to improve the clinical management of HCC patients. TRIAL REGISTRATION: Clinical Trials, NCT05485792 . Registered 1 August 2022, Retrospectively registered.

Increased 18F-FAPI Uptake in Radiation-Induced Liver Injury.

ABSTRACT: A 51-year-old woman with breast cancer underwent a complete surgical resection and chemoradiotherapy approximately 3 months ago. Follow-up abdominal ultrasound detected a new lesion with decreased echogenicity in the hepatic segment IV/VIII. 18F-FDG PET/CT showed the hepatic lesion without abnormal uptake. The patient was subsequently enrolled in a clinical trial of 18F-FAPI PET/CT to assess the hepatic lesion. An intense 18F-FAPI activity was identified in the hepatic lesion. Finally, pathological analysis combined with imaging follow-up confirmed the diagnosis of radiation-induced liver injury.

A rapid and sensitive method for determination of methylene-diphosphonate in rat bone using liquid chromatography-mass spectrometry.

A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for the determination of methylene-diphosphonate (MDP) in rat bone. This method employed derivatization of MDP and allowed rapid and sensitive quantification of MDP in rat shin bone. The analyte was extracted from the bone tissues with phosphoric acid and derivatized to MDP tetramethyl phosphonate using trimethylsilyl diazomethane (TMS-DAM). MDP tetramethyl phosphonate was then quantified by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS), with high selectivity, accuracy, and precision. The total run time was 6.5 min. The lower limit of quantification was 2.00 ng/mL. The intra- and inter-assay precision (in RSD) calculated from quality control samples was less than 15%, and the accuracy was between 98.1% and 100.2%. The analytical process for the determination of MDP in rat bone is fully described, which is a pivotal step for further biomedical research on MDP.

Raman Spectroscopy to Enhance Investigative Lead Information in Automotive Clearcoats.

A new method to determine the make and model of a vehicle from an automotive paint sample recovered at the crime scene of a vehicle-related fatality such as a hit-and-run using Raman microscopy has been developed. Raman spectra were collected from 118 automotive paint samples from six General Motors (GM) vehicle assembly plants to investigate the discrimination power of Raman spectroscopy for automotive clearcoats using a genetic algorithm for pattern recognition that incorporates model inference and sample error in the variable selection process. Each vehicle assembly plant pertained to a specific vehicle model. The spectral region between 1802 and 697 cm-1 was found to be supportive of the discrimination of these six GM assembly plants. By comparison, only one of the six automotive assembly plants could be differentiated from the other five assembly plants using Fourier transform infrared spectroscopy (FT-IR), which is the most widely used analytical method for the examination of automotive paint) and the genetic algorithm for pattern recognition. The results of this study indicate that Raman spectroscopy in combination with pattern recognition methods offers distinct advantages over FT-IR for the identification and discrimination of automotive clearcoats.

SARS-CoV-2 hijacks neutralizing dimeric IgA for nasal infection and injury in Syrian hamsters1.

Prevention of robust severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection in nasal turbinate (NT) requires in vivo evaluation of IgA neutralizing antibodies. Here, we report the efficacy of receptor binding domain (RBD)-specific monomeric B8-mIgA1 and B8-mIgA2, and dimeric B8-dIgA1, B8-dIgA2 and TH335-dIgA1 against intranasal SARS-CoV-2 challenge in Syrian hamsters. These antibodies exhibited comparable neutralization potency against authentic virus by competing with human angiotensin converting enzyme-2 (ACE2) receptor for RBD binding. While reducing viral loads in lungs significantly, prophylactic intranasal B8-dIgA unexpectedly led to high amount of infectious viruses and extended damage in NT compared to controls. Mechanistically, B8-dIgA failed to inhibit SARS-CoV-2 cell-to-cell transmission, but was hijacked by the virus through dendritic cell-mediated trans-infection of NT epithelia leading to robust nasal infection. Cryo-EM further revealed B8 as a class II antibody binding trimeric RBDs in 3-up or 2-up/1-down conformation. Neutralizing dIgA, therefore, may engage an unexpected mode of SARS-CoV-2 nasal infection and injury.

[Network Meta-analysis of efficacy of Chinese patent medicine in treatment of inflammatory response in diabetic nephropathy].

This study aimed to evaluate the efficacy and safety of various Chinese patent medicines in the treatment of inflammatory response in diabetic nephropathy(DN) based on network Meta-analysis. Randomized controlled trial(RCT) of oral Chinese patent medicines for improving inflammatory response in patients with DN was retrieved from CNKI, Wanfang, VIP, SinoMed, PubMed, Cochrane Library, EMbase, Web of Science, and other databases from database inception to October 2022. All investigators independently screened the literature, extracted data, and evaluated the quality. Stata 16.0 software and RevMan 5.4.1 were used to analyze the data of the literature that met the quality standards. Finally, 53 RCTs were included, involving 6 Chinese patent medicines. The total sample size was 4 891 cases, including 2 449 cases in the test group and 2 442 cases in the control group. The network Meta-analysis showed that(1) in terms of reducing TNF-α, the top 3 optimal interventions according to the surface under the cumulative ranking curve(SUCRA) were Shenshuaining Capsules/Granules/Tablets + conventional western medicine, Jinshuibao Capsules + conventional western medicine, and Niaoduqing Granules + conventional western medicine.(2) In terms of reducing hs-CRP, the top 3 optimal interventions according to SUCRA were Bailing Capsules + conventional western medicine, Tripterygium Glycosides Tablets + conventional western medicine, and Shenshuaining Capsules/Granules/Tablets + conventional western medicine.(3) In terms of reducing IL-6, the top 3 optimal interventions according to SUCRA were Bailing Capsules + conventional western medicine, Tripterygium Glycosides Tablets + conventional western medicine, and Jinshuibao Capsules + conventional western medicine.(4) In terms of reducing UAER, the top 3 optimal interventions according to SUCRA were Shenshuaining Capsules/Granules/Tablets + conventional western medicine, Huangkui Capsules + conventional western medicine, and Jinshuibao Capsules + conventional western medicine.(5) In terms of reducing Scr, the top 3 optimal interventions according to SUCRA were Jinshuibao Capsules + conventional western medicine, Niaoduqing Granules + conventional wes-tern medicine, and Tripterygium Glycosides Tablets + conventional western medicine.(6) In terms of reducing BUN, the first 3 optimal interventions according to SUCRA were Niaoduqing Granules + conventional western medicine, Tripterygium Glycosides Tablets + conventional western medicine, and Huangkui Capsules + conventional western medicine.(7) In terms of improving the clinical total effective rate, the first 3 optimal interventions according to SUCRA were Jinshuibao Capsules + conventional western medicine, Niaoduqing Granu-les + conventional western medicine, and Huangkui Capsules + conventional western medicine. The results showed that the combination of western medicine and Chinese patent medicine could reduce the expression of serum inflammatory factors TNF-α, hs-CRP, and IL-6 and inhibit the inflammatory response. The combination of western medicine and Chinese patent medicine was superior to western medicine alone in reducing Scr, BUN, and UAER, and improving the total effective rate of treatment. Due to the limitation of the quantity and quality of literature included, the above conclusions need to be validated by more high-quality studies.

Optical coherence tomography angiography-guided vs indocyanine green angiography-guided half-dose photodynamic therapy for acute central serous chorioretinopathy: 6-month randomized trial results.

PURPOSE: This study aimed to compare the anatomic and functional results of optical coherence tomography angiography (OCTA)-guided half-dose photodynamic therapy (PDT) versus indocyanine green angiography (ICGA)-guided PDT in eyes with acute central serous chorioretinopathy (CSC). METHODS: One hundred and thirty-one eyes of 131 patients with acute central serous chorioretinopathy (CSC) were recruited, and randomly assigned to the OCTA-guided group and ICGA-guided group. The primary outcome measures were the rates of complete subretinal fluid (SRF) resolution at 1 month, 3 months, and 6 months. The secondary outcomes included best-corrected visual acuity (BCVA), central retinal thickness (CRT), choroidal capillary flow deficit density at each scheduled visit, and recurrence rate of SRF at 3 months and 6 months. RESULTS: There were 110 eyes that finished the follow-up, with 56 eyes in the OCTA-guided group and 54 eyes in the ICGA guided group. OCTA-guided PDT was demonstrated to be noninferior to ICGA-guided PDT for SRF resolution rate at 1 months and 6 months (P = 0.021 and P = 0.037), but not at 3 months for acute CSC (P = 0.247). The average CRT of the ICGA-guided group was significantly lower than that of the OCTA-guided group at 3-month visit (P = 0.046), but no significant difference was found between them at the 1-month and 6-month visits (P = 0.891 and 0.527). There was no significant difference between the two groups for BCVA (P = 0.359, 0.700, and 0.143, respectively) and the deficit area on CC (P = 0.537, 0.744,and 0.604, respectively) at 1, 3, and 6 months. CONCLUSION: OCTA may replace ICGA to guide PDT for the treatment of acute CSC and their follow-up.

Structural basis of α1A-adrenergic receptor activation and recognition by an extracellular nanobody.

The α1A-adrenergic receptor (α1AAR) belongs to the family of G protein-coupled receptors that respond to adrenaline and noradrenaline. α1AAR is involved in smooth muscle contraction and cognitive function. Here, we present three cryo-electron microscopy structures of human α1AAR bound to the endogenous agonist noradrenaline, its selective agonist oxymetazoline, and the antagonist tamsulosin, with resolutions range from 2.9 Å to 3.5 Å. Our active and inactive α1AAR structures reveal the activation mechanism and distinct ligand binding modes for noradrenaline compared with other adrenergic receptor subtypes. In addition, we identified a nanobody that preferentially binds to the extracellular vestibule of α1AAR when bound to the selective agonist oxymetazoline. These results should facilitate the design of more selective therapeutic drugs targeting both orthosteric and allosteric sites in this receptor family.

The characteristic of the key aroma-active components in white tea using GC-TOF-MS and GC-olfactometry combined with sensory-directed flavor analysis.

BACKGROUND: White tea has become more and more popular with consumers due to its health benefits and unique flavor. However, the key aroma-active compounds of white tea during the aging process are still unclear. Thus, the key aroma-active compounds of white tea during the aging process were investigated using gas chromatography-time-of-flight-mass spectrometry (GC-TOF-MS) and gas chromatography-olfactometry (GC-O) combined with sensory-directed flavor analysis. RESULTS: A total of 127 volatile compounds were identified from white tea samples with different aging years by GC-TOF-MS. Fifty-eight aroma-active compounds were then determined by GC-O, and 19 of them were further selected as the key aroma-active compounds based on modified frequency (MF) and odor activity value (OAV). CONCLUSION: Aroma recombination and omission testing confirmed that 1-octen-3-ol, linalool, phenethyl alcohol, geraniol, (E)-ß-ionone, α-ionone, hexanal, phenylacetaldehyde, nonanal, (E, Z)-(2,6)-nonadienal, safranal, γ-nonalactone and 2-amylfuran were the common key aroma-active compounds to all samples. Cedrol, linalool oxide II and methyl salicylate were confirmed peculiar in new white tea, while ß-damascenone and jasmone were peculiar in aged white tea. This work will offer support for further studies on the material basis of flavor formation of white tea. © 2023 Society of Chemical Industry.

Exosomes derived from human umbilical cord mesenchymal stem cells alleviate Parkinson's disease and neuronal damage through inhibition of microglia.

Microglia-mediated inflammatory responses have been shown to play a crucial role in Parkinson's disease. In addition, exosomes derived from mesenchymal stem cells have shown anti-inflammatory effects in the treatment of a variety of diseases. However, whether they can protect neurons in Parkinson's disease by inhibiting microglia-mediated inflammatory responses is not yet known. In this study, exosomes were isolated from human umbilical cord mesenchymal stem cells and injected into a 6-hydroxydopamine-induced rat model of Parkinson's disease. We found that the exosomes injected through the tail vein and lateral ventricle were absorbed by dopaminergic neurons and microglia on the affected side of the brain, where they repaired nigral-striatal dopamine system damage and inhibited microglial activation. Furthermore, in an in vitro cell model, pretreating lipopolysaccharide-stimulated BV2 cells with exosomes reduced interleukin-1ß and interleukin-18 secretion, prevented the adoption of pyroptosis-associated morphology by BV2 cells, and increased the survival rate of SH-SY5Y cells. Potential targets for treatment with human umbilical cord mesenchymal stem cells and exosomes were further identified by high-throughput microRNA sequencing and protein spectrum sequencing. Our findings suggest that human umbilical cord mesenchymal stem cells and exosomes are a potential treatment for Parkinson's disease, and that their neuroprotective effects may be mediated by inhibition of excessive microglial proliferation.

Infection with wild-type SARS-CoV-2 elicits broadly neutralizing and protective antibodies against omicron subvariants.

The omicron variants of SARS-CoV-2 have substantial ability to escape infection- and vaccine-elicited antibody immunity. Here, we investigated the extent of such escape in nine convalescent patients infected with the wild-type SARS-CoV-2 during the first wave of the pandemic. Among the total of 476 monoclonal antibodies (mAbs) isolated from peripheral memory B cells, we identified seven mAbs with broad neutralizing activity to all variants tested, including various omicron subvariants. Biochemical and structural analysis indicated the majority of these mAbs bound to the receptor-binding domain, mimicked the receptor ACE2 and were able to accommodate or inadvertently improve recognition of omicron substitutions. Passive delivery of representative antibodies protected K18-hACE2 mice from infection with omicron and beta SARS-CoV-2. A deeper understanding of how the memory B cells that produce these antibodies could be selectively boosted or recalled can augment antibody immunity against SARS-CoV-2 variants.

Elevated number and density of macrophage-like cell as a novel inflammation biomarker in diabetic macular edema.

To quantitatively analyze the number and density of macrophage-like cells (MLCs) at the vitreoretinal interface at macular region in diabetic retinopathy (DR) with and without diabetic macular edema (DME). This cross-sectional study involved 240 eyes of 146 treatment-naïve DR patients, including 151 eyes with DME. The number and density of MLCs were analyzed quantitatively using optical coherence tomography angiography (OCTA) and were compared between DME and non-DME eyes as well as proliferative DR (PDR) and non-PDR (NPDR) eyes. Correlation between MLCs density and vessel density of macular superficial capillary plexus (SCP) at macular region was evaluated. The number and density of macular MLCs were both elevated in DME group compared to non-DME group (all p < 0.001). The morphology of MLCs in DME eyes appeared larger and fuller. NPDR eyes had higher number and density of MLCs (p = 0.027 and 0.026), greater central macular thickness (CMT) (p = 0.002) and vessel density than PDR eyes in non-DME group but comparable to PDR eyes in DME group. The number and density of MLCs at macular region were significantly higher with larger and fuller morphology in DR patients with DME than those without DME. PDR eyes had fewer MLCs than NPDR eyes for DR eyes without DME.