OsLCD3 interacts with OsSAMS1 to regulate grain size via ethylene/polyamine homeostasis control.

A fundamental question in developmental biology is how to regulate grain size to improve crop yields. Despite this, little is still known about the genetics and molecular mechanisms regulating grain size in crops. Here, we provide evidence that a putative protein kinase-like (OsLCD3) interacts with the S-adenosyl-L-methionine synthetase 1 (OsSAMS1) and determines the size and weight of grains. OsLCD3 mutation (lcd3) significantly increased grain size and weight by promoting cell expansion in spikelet hull, whereas its overexpression caused negative effects, suggesting that grain size was negatively regulated by OsLCD3. Importantly, lcd3 and OsSAMS1 overexpression (SAM1OE) led to large and heavy grains, with increased ethylene and decreased polyamines production. Based on genetic analyses, it appears that OsLCD3 and OsSAMS1 control rice grain size in part by ethylene/polyamine homeostasis. The results of this study provide a genetic and molecular understanding of how the OsLCD3-OsSAMS1 regulatory module regulates grain size, suggesting that ethylene/polyamine homeostasis is an appropriate target for improving grain size and weight.

An efficient method for detecting membrane protein oligomerization and complex using 05SAR-PAGE.

Oligomerization is an important feature of proteins, which gives a defined quaternary structure to complete the biological functions. Although frequently observed in membrane proteins, characterizing the oligomerization state remains complicated and time-consuming. In this study, 0.05% (w/v) sarkosyl-polyacrylamide gel electrophoresis (05SAR-PAGE) was used to identify the oligomer states of the membrane proteins CpxA, EnvZ, and Ma-Mscl with high sensitivity. Furthermore, two-dimensional electrophoresis (05SAR/sodium dodecyl sulfate-PAGE) combined with western blotting and liquid chromatography-tandem mass spectrometry was successfully applied to study the complex of CpxA/OmpA in cell lysate. The results indicated that 05SAR-PAGE is an efficient, economical, and practical gel method that can be widely used for the identification of membrane protein oligomerization and the analysis of weak protein interactions.

Aberrant accumulation of ceramides in mitochondria triggers cell death by inducing autophagy in Arabidopsis.

Sphingolipids are membrane lipids and play critical roles in signal transduction. Ceramides are central components of sphingolipid metabolism that are involved in cell death. However, the mechanism of ceramides regulating cell death in plants remains unclear. Here, we found that ceramides accumulated in mitochondria of accelerated cell death 5 mutant (acd5), and expression of mitochondrion-localized ceramide kinase (ACD5) suppressed mitochondrial ceramide accumulation and the acd5 cell death phenotype. Using immuno-electron microscopy, we observed hyperaccumulation of ceramides in acer acd5 double mutants, which are characterized by mutations in both ACER (alkaline ceramidase) and ACD5 genes. The results confirmed that plants with specific ceramide accumulation exhibited localization of ceramides to mitochondria, resulting in an increase in mitochondrial reactive oxygen species production. Interestingly, when compared with the wild type, autophagy-deficient mutants showed stronger resistance to ceramide-induced cell death. Lipid profiling analysis demonstrated that plants with ceramide accumulation exhibited a significant increase in phosphatidylethanolamine levels. Furthermore, exogenous ceramide treatment or endogenous ceramide accumulation induces autophagy. When exposed to exogenous ceramides, an increase in the level of the autophagy-specific ubiquitin-like protein, ATG8e, associated with mitochondria, where it directly bound to ceramides. Taken together, we propose that the accumulation of ceramides in mitochondria can induce cell death by regulating autophagy.

The long-term outcome of CT-guided radiofrequency ablation of the peripheral branches of the trigeminal nerve in trigeminal neuralgia.

Radiofrequency thermocoagulation (RFTC) of the peripheral branches of the trigeminal nerve has been used for trigeminal neuralgia. However, the long-term outcomes of radiofrequency thermocoagulation have not been established. To evaluate the long-term efficacy of RFTC of peripheral branches in patients with refractory trigeminal neuralgia. A retrospective cohort study was conducted in a comprehensive medical center in China. Patients who underwent radiofrequency thermocoagulation of peripheral branches for refractory trigeminal neuralgia from May 2014 to March 2021 were included for analysis. A total of 84 patients with refractory trigeminal neuralgia underwent 105 procedures. BNI I-II which represents treatment success was achieved in 76/84 (90%) patients and 93/105 (89%) procedures. During follow-up, BNI I and II were maintained in 64/76 (84%), 40/73 (55%), 20/67 (30%), 17/65 (26%), 12/61 (20%), and 8/58 (14%) of patients at 1, 2, 3, 4, 5, and 6 years, after the first procedure, respectively. For all the 105 procedures, BNI I and II were maintained in 68/93 (73%), 41/89(46%), 22/82(27%), 15/79 (19%), 8/74 (11%), and 3/72 (4%) at 1, 2, 3, 4, 5, and 6 years, respectively. There is no significant difference between the first and repeat thermocoagulation in terms of immediate (90% vs. 81%, P=0.140) and long-term efficacies (24 months vs.18 months, P=0.266). Radiofrequency thermocoagulation resulted in better long-term outcomes in patients with typical purely paroxysmal pain (24 months vs. 11 months, P=0.033). Radiofrequency ablation of the peripheral branches of the trigeminal nerve might be a safe and effective method in the treatment of refractory trigeminal neuralgia.

Application of Copper-Sulfur Compound Electrode Materials in Supercapacitors.

Supercapacitors (SCs) are a novel type of energy storage device that exhibit features such as a short charging time, a long service life, excellent temperature characteristics, energy saving, and environmental protection. The capacitance of SCs depends on the electrode materials. Currently, carbon-based materials, transition metal oxides/hydroxides, and conductive polymers are widely used as electrode materials. However, the low specific capacitance of carbon-based materials, high cost of transition metal oxides/hydroxides, and poor cycling performance of conductive polymers as electrodes limit their applications. Copper-sulfur compounds used as electrode materials exhibit excellent electrical conductivity, a wide voltage range, high specific capacitance, diverse structures, and abundant copper reserves, and have been widely studied in catalysis, sensors, supercapacitors, solar cells, and other fields. This review summarizes the application of copper-sulfur compounds in SCs, details the research directions and development strategies of copper-sulfur compounds in SCs, and analyses and summarizes the research hotspots and outlook, so as to provide a reference and guidance for the use of copper-sulfur compounds.

Ceramides regulate defense response by binding to RbohD in Arabidopsis.

Sphingolipids, a class of bioactive lipids, play a critical role in signal transduction. Ceramides, which are central components of sphingolipid metabolism, are involved in plant development and defense. However, the mechanistic link between ceramides and downstream signaling remains unclear. Here, the mutation of alkaline ceramidase in a ceramide kinase mutant acd5 resulted in spontaneous programmed cell death early in development and was accompanied by ceramide accumulation, while other types of sphingolipids, such as long chain base, glucosylceramide, and glycosyl inositol phosphorylceramide, remained at the same level as the wild-type plants. Analysis of the transcriptome indicated that genes related to the salicylic acid (SA) pathway and oxidative stress pathway were induced dramatically in acer acd5 plants. Comparison of the level of reactive oxygen species (ROS), SA, and ceramides in the wild-type and acer acd5 plants at different developmental stages indicated that the acer acd5 mutant exhibited constitutive activation of SA and ROS signaling, which occurred simultaneously with the alteration of ceramides. Overexpressing NahG in the acer acd5 mutant could completely suppress its cell death and ceramide accumulation, while benzo-(1,2,3)-thiadiazole-7-carbothioc acid S-methyl ester treatment restored its phenotype again. Moreover, we found that the plasma membrane of acer acd5 mutant was the main site of ROS production. Ceramides accumulated in the plasma membrane of acer acd5, directly binding and activating the NADPH oxidase RbohD and promoting hydrogen peroxide generation and SA- or defense-related gene activation. Our data illustrated that ceramides play an essential role in plant defense.

Embryological observations on seed abortion in Hibiscus syriacus L. and physiological studies on nutrients, enzyme activity and endogenous hormones.

Under natural conditions, most Hibiscus syriacus L. individuals form very few mature seeds or the mature seeds that do form are of poor quality. As a result, seed yield is poor and seeds have low natural germinability. These phenomena strongly hinder utilization of the excellent germplasm resources of H. syriacus. The study has shown that pollen activity and stigma receptivity were high on the day of anthesis, and the pistils and stamens were fertile. Pollen release and stigma receptivity were synchronous. But in styles following self and cross-pollination, pollen tube abnormalities (distortion and twisting of the pollen tubes) and callose deposition were observed. Cross-pollinated pollen tubes elongated faster and fewer pollen tube abnormalities were observed compared with self-pollinated pollen tubes. And during embryo development, abnormalities during the heart-shaped embryo stage led to embryo abortion. Imbalance in antioxidant enzyme activities and low contents of auxin and cytokinin during early stages of embryo development may affect embryo development. Therefore, a low frequency of outcrossing and mid-development embryo abortion may be important developmental causes of H. syriacus seed abortion. Nutrient deficiencies, imbalance in antioxidant enzyme activities, and a high content of abscisic acid at advanced stages of seed development may be physiological causes of seed abortion.

Effectiveness of percutaneous balloon compression (PBC) in improving physical function and quality of life in trigeminal neuralgia: a retrospective study.

OBJECTIVE: To evaluate the effectiveness of percutaneous balloon compression (PBC) in treating trigeminal neuralgia (TN) and determine improvements in quality of life (QoL) and daily functional status. METHODS: Data from primary TN (pTN) patients treated with PBC from December 2018 to April 2021 were retrospectively analyzed. Short-Form 36 (SF-36) Health Survey and Functional Independence Measure (FIM) assessments were used to evaluate patients' QoL and physical function every 6 months after surgery, and facial pain was evaluated every 3 to 6 months post-surgery. RESULTS: A total of 80 pTN patients were enrolled for analysis. The Barrow Neurological Institute (BNI) scores of I-II were achieved in 67 (83.8%) patients immediately after the surgery. The estimated rates of BNI I-II pain relief at one, two, and three years were 94.2%, 87.6%, and 83.2%, respectively. All aspects of the SF-36 questionnaire were significantly improved after the PBC, especially in terms of role physical (RP), bodily pain (BP), and social functioning (SF). Patients' functional outcomes measured by FIM at the 6-month follow-up examination were 108.6 ± 9.9, which was significantly improved compared with the pretreatment scores (90.8 ± 12.7). There was no difference between the severity of facial numbness in FIM and any item of the SF-36 except RP (P = 0.004) at 6 months after surgery. There was also no difference in SF-36 and FIM between patients with or without facial hyperalgesia. CONCLUSIONS: PBC can produce long-term and stable pain relief and significantly improve the patient's QoL and physical function. However, further well-designed, high-level, evidence-based studies are needed to precisely assess the efficacy of PBC for pTN patients.

Identification of Key Influencers for Secondary Distribution of HIV Self-Testing Kits Among Chinese Men Who Have Sex With Men: Development of an Ensemble Machine Learning Approach.

BACKGROUND: HIV self-testing (HIVST) has been rapidly scaled up and additional strategies further expand testing uptake. Secondary distribution involves people (defined as "indexes") applying for multiple kits and subsequently sharing them with people (defined as "alters") in their social networks. However, identifying key influencers is difficult. OBJECTIVE: This study aimed to develop an innovative ensemble machine learning approach to identify key influencers among Chinese men who have sex with men (MSM) for secondary distribution of HIVST kits. METHODS: We defined three types of key influencers: (1) key distributors who can distribute more kits, (2) key promoters who can contribute to finding first-time testing alters, and (3) key detectors who can help to find positive alters. Four machine learning models (logistic regression, support vector machine, decision tree, and random forest) were trained to identify key influencers. An ensemble learning algorithm was adopted to combine these 4 models. For comparison with our machine learning models, self-evaluated leadership scales were used as the human identification approach. Four metrics for performance evaluation, including accuracy, precision, recall, and F1-score, were used to evaluate the machine learning models and the human identification approach. Simulation experiments were carried out to validate our approach. RESULTS: We included 309 indexes (our sample size) who were eligible and applied for multiple test kits; they distributed these kits to 269 alters. We compared the performance of the machine learning classification and ensemble learning models with that of the human identification approach based on leadership self-evaluated scales in terms of the 2 nearest cutoffs. Our approach outperformed human identification (based on the cutoff of the self-reported scales), exceeding by an average accuracy of 11.0%, could distribute 18.2% (95% CI 9.9%-26.5%) more kits, and find 13.6% (95% CI 1.9%-25.3%) more first-time testing alters and 12.0% (95% CI -14.7% to 38.7%) more positive-testing alters. Our approach could also increase the simulated intervention's efficiency by 17.7% (95% CI -3.5% to 38.8%) compared to that of human identification. CONCLUSIONS: We built machine learning models to identify key influencers among Chinese MSM who were more likely to engage in secondary distribution of HIVST kits. TRIAL REGISTRATION: Chinese Clinical Trial Registry (ChiCTR) ChiCTR1900025433; https://www.chictr.org.cn/showproj.html?proj=42001.

Decompression versus decompression plus fusion for treating degenerative lumbar spinal stenosis: A systematic review and meta-analysis.

BACKGROUND: Degenerative lumbar spinal stenosis (DLSS) is a complex clinical syndrome that leads to spinal compression. Decompression with fusion has been the most commonly used surgical procedure for treating DLSS symptoms for many years. However, the exact role of fusion and its effectiveness in DLSS therapy has recently been debated. OBJECTIVE: The main purpose of this study was to compare the efficacy and safety of decompression alone and decompression plus fusion in the treatment of DLSS with or without spondylolisthesis. STUDY DESIGN: A systematic review and meta-analysis of the therapeutic effects of decompression for DLSS with or without the combination of fusion. METHODS: A literature search in five relevant databases, including Web of Science, PubMed, Embase, Medline, and Cochrane Library was performed from the inception of the database to March 2022. Only randomized controlled trials (RCTs) assessing the comparison between decompression and decompression plus fusion for DLSS were included. RESULTS: A total of seven studies, 894 patients were analyzed in this meta-analysis. Among these, 443 patients were included in the decompression plus fusion group while 451 patients were included in the decompression alone group. Pooled analysis showed that the combination of decompression with fusion had no superior benefits to decompression alone in terms of Oswestry Disability Index (ODI) score in the first 2 years and long-term follow-up after surgery, also no significant difference in the improvement of back and leg pain was found between two groups. Adding fusion to decompression was associated with a longer operation time, higher complication rate, more blood loss, and extended hospital stay. Furthermore, there was no difference in reoperation rates and patients' satisfaction between the two groups at the last follow-up. CONCLUSION: Decompression plus fusion may not be associated with a better clinical outcome in ODI scores and back or leg pain improvement but with a longer duration of operation time, extended hospital stay, and more blood loss.

The immune components ENHANCED DISEASE SUSCEPTIBILITY 1 and PHYTOALEXIN DEFICIENT 4 are required for cell death caused by overaccumulation of ceramides in Arabidopsis.

Sphingolipids have key functions in plant membrane structure and signaling. Perturbations of plant sphingolipid metabolism often induce cell death and salicylic acid (SA) accumulation; SA accumulation, in turn, promotes sphingolipid metabolism and further cell death. However, the underlying molecular mechanisms remain unclear. Here, we show that the Arabidopsis thaliana lipase-like protein ENHANCED DISEASE SUSCEPTIBILITY 1 (EDS1) and its partner PHYTOALEXIN DEFICIENT 4 (PAD4) participate in sphingolipid metabolism and associated cell death. The accelerated cell death 5 (acd5) mutants accumulate ceramides due to a defect in ceramide kinase and show spontaneous cell death. Loss of function of EDS1, PAD4 or SALICYLIC ACID INDUCTION DEFICIENT 2 (SID2) in the acd5 background suppressed the acd5 cell death phenotype and prevented ceramide accumulation. Treatment with the SA analogue benzothiadiazole partially restored sphingolipid accumulation in the acd5 pad4 and acd5 eds1 double mutants, showing that the inhibitory effect of the pad4-1 and eds1-2 mutations on acd5-conferred sphingolipid accumulation partly depends on SA. Moreover, the pad4-1 and eds1-2 mutations substantially rescued the susceptibility of the acd5 mutant to Botrytis cinerea. Consistent with this, B. cinerea-induced ceramide accumulation requires PAD4 or EDS1. Finally, examination of plants overexpressing the ceramide synthase gene LAG1 HOMOLOGUE2 suggested that EDS1, PAD4 and SA are involved in long-chain ceramide metabolism and ceramide-associated cell death. Collectively, our observations reveal that EDS1 and PAD4 mediate ceramide (especially long-chain ceramide) metabolism and associated cell death, by SA-dependent and SA-independent pathways.

Monetary incentives and peer referral in promoting secondary distribution of HIV self-testing among men who have sex with men in China: A randomized controlled trial.

BACKGROUND: Digital network-based methods may enhance peer distribution of HIV self-testing (HIVST) kits, but interventions that can optimize this approach are needed. We aimed to assess whether monetary incentives and peer referral could improve a secondary distribution program for HIVST among men who have sex with men (MSM) in China. METHODS AND FINDINGS: Between October 21, 2019 and September 14, 2020, a 3-arm randomized controlled, single-blinded trial was conducted online among 309 individuals (defined as index participants) who were assigned male at birth, aged 18 years or older, ever had male-to-male sex, willing to order HIVST kits online, and consented to take surveys online. We randomly assigned index participants into one of the 3 arms: (1) standard secondary distribution (control) group (n = 102); (2) secondary distribution with monetary incentives (SD-M) group (n = 103); and (3) secondary distribution with monetary incentives plus peer referral (SD-M-PR) group (n = 104). Index participants in 3 groups were encouraged to order HIVST kits online and distribute to members within their social networks. Members who received kits directly from index participants or through peer referral links from index MSM were defined as alters. Index participants in the 2 intervention groups could receive a fixed incentive ($3 USD) online for the verified test result uploaded to the digital platform by each unique alter. Index participants in the SD-M-PR group could additionally have a personalized peer referral link for alters to order kits online. Both index participants and alters needed to pay a refundable deposit ($15 USD) for ordering a kit. All index participants were assigned an online 3-month follow-up survey after ordering kits. The primary outcomes were the mean number of alters motivated by index participants in each arm and the mean number of newly tested alters motivated by index participants in each arm. These were assessed using zero-inflated negative binomial regression to determine the group differences in the mean number of alters and the mean number of newly tested alters motivated by index participants. Analyses were performed on an intention-to-treat basis. We also conducted an economic evaluation using microcosting from a health provider perspective with a 3-month time horizon. The mean number of unique tested alters motivated by index participants was 0.57 ± 0.96 (mean ± standard deviation [SD]) in the control group, compared with 0.98 ± 1.38 in the SD-M group (mean difference [MD] = 0.41),and 1.78 ± 2.05 in the SD-M-PR group (MD = 1.21). The mean number of newly tested alters motivated by index participants was 0.16 ± 0.39 (mean ± SD) in the control group, compared with 0.41 ± 0.73 in the SD-M group (MD = 0.25) and 0.57 ± 0.91 in the SD-M-PR group (MD = 0.41), respectively. Results indicated that index participants in intervention arms were more likely to motivate unique tested alters (control versus SD-M: incidence rate ratio [IRR = 2.98, 95% CI = 1.82 to 4.89, p-value < 0.001; control versus SD-M-PR: IRR = 3.26, 95% CI = 2.29 to 4.63, p-value < 0.001) and newly tested alters (control versus SD-M: IRR = 4.22, 95% CI = 1.93 to 9.23, p-value < 0.001; control versus SD-M-PR: IRR = 3.49, 95% CI = 1.92 to 6.37, p-value < 0.001) to conduct HIVST. The proportion of newly tested testers among alters was 28% in the control group, 42% in the SD-M group, and 32% in the SD-M-PR group. A total of 18 testers (3 index participants and 15 alters) tested as HIV positive, and the HIV reactive rates for alters were similar between the 3 groups. The total costs were $19,485.97 for 794 testers, including 450 index participants and 344 alter testers. Overall, the average cost per tester was $24.54, and the average cost per alter tester was $56.65. Monetary incentives alone (SD-M group) were more cost-effective than monetary incentives with peer referral (SD-M-PR group) on average in terms of alters tested and newly tested alters, despite SD-M-PR having larger effects. Compared to the control group, the cost for one more alter tester in the SD-M group was $14.90 and $16.61 in the SD-M-PR group. For newly tested alters, the cost of one more alter in the SD-M group was $24.65 and $49.07 in the SD-M-PR group. No study-related adverse events were reported during the study. Limitations include the digital network approach might neglect individuals who lack internet access. CONCLUSIONS: Monetary incentives alone and the combined intervention of monetary incentives and peer referral can promote the secondary distribution of HIVST among MSM. Monetary incentives can also expand HIV testing by encouraging first-time testing through secondary distribution by MSM. This social network-based digital approach can be expanded to other public health research, especially in the era of the Coronavirus Disease 2019 (COVID-19). TRIAL REGISTRATION: Chinese Clinical Trial Registry (ChiCTR) ChiCTR1900025433.

Jasmonates modulate sphingolipid metabolism and accelerate cell death in the ceramide kinase mutant acd5.

Sphingolipids are structural components of the lipid bilayer that acts as signaling molecules in many cellular processes, including cell death. Ceramides, key intermediates in sphingolipid metabolism, are phosphorylated by the ceramide kinase ACCELERATED CELL DEATH5 (ACD5). The loss of ACD5 function leads to ceramide accumulation and spontaneous cell death. Here, we report that the jasmonate (JA) pathway is activated in the Arabidopsis (Arabidopsis thaliana) acd5 mutant and that methyl JA treatment accelerates ceramide accumulation and cell death in acd5. Moreover, the double mutants of acd5 with jasmonate resistant1-1 and coronatine insensitive1-2 exhibited delayed cell death, suggesting that the JA pathway is involved in acd5-mediated cell death. Quantitative sphingolipid profiling of plants treated with methyl JA indicated that JAs influence sphingolipid metabolism by increasing the levels of ceramides and hydroxyceramides, but this pathway is dramatically attenuated by mutations affecting JA pathway proteins. Furthermore, we showed that JAs regulate the expression of genes encoding enzymes in ceramide metabolism. Together, our findings show that JAs accelerate cell death in acd5 mutants, possibly by modulating sphingolipid metabolism and increasing ceramide levels.

Arabidopsis alkaline ceramidase ACER functions in defense against insect herbivory.

Plant sphingolipids are important membrane components and bioactive molecules in development and defense responses. However, the function of sphingolipids in plant defense, especially against herbivores, is not fully understood. Here, we report that Spodoptera exigua feeding affects sphingolipid metabolism in Arabidopsis, resulting in increased levels of sphingoid long-chain bases, ceramides, and hydroxyceramides. Insect-induced ceramide and hydroxyceramide accumulation is dependent on the jasmonate signaling pathway. Loss of the Arabidopsis alkaline ceramidase ACER increases ceramides and decreases long-chain base levels in plants; in this work, we found that loss of ACER enhances plant resistance to S. exigua and improves response to mechanical wounding. Moreover, acer-1 mutants exhibited more severe root-growth inhibition and higher anthocyanin accumulation than wild-type plants in response to methyl jasmonate treatment, indicating that loss of ACER increases sensitivity to jasmonate and that ACER functions in jasmonate-mediated root growth and secondary metabolism. Transcript levels of ACER were also negatively regulated by jasmonates, and this process involves the transcription factor MYC2. Thus, our findings reveal that ACER is involved in mediating jasmonate-related plant growth and defense and that jasmonates function in regulating the expression of ACER.

Cellular transport of uranium and its cytotoxicity effects on CHO-k1 cells.

Uranium is a radioactive heavy metal and a significant public health concern; however, its associated underlying toxicological mechanisms remain largely unknown. In this work, the uptake and efflux processes of uranium in CHO-k1 cells were studied and the cytotoxicity effects were explored. It was found that both the uptake and efflux processes took place rapidly and half of the internalized uranium was expelled within 8 h. The uranium exposure caused a decrease of cell viability and adhesion ability in a dose-dependent manner and blocked the cell cycle at the G1 stage. In addition, gene expression analysis revealed relative changes in the transcription of metabolism related genes. Further studies revealed that the cytotoxicity of uranium could be alleviated by exposing cells to a lower temperature or by the addition of amantadine-HCl, an endocytosis inhibitor. Interestingly, after uranium exposure, needle-like precipitates were observed in both intracellular and extracellular regions. These findings collectively suggest that the cellular transport of uranium is a rapid process that disturbs cell metabolism and induces cytotoxicity, and this impact could be reduced by slowing down endocytic processes.

A community-based organisation-led HIV self-testing program among men who have sex with men in China is cheaper and more effective than facility-based HIV testing: an economic evaluation.

BACKGROUND: HIV self-testing (HIVST) is effective in improving the uptake of HIV testing among key populations. Complementary data on the economic evaluation of HIVST is critical for planning and scaling up HIVST. This study aimed to evaluate the cost of a community-based organisation (CBO)-led HIVST model implemented in China. METHODS: An economic evaluation was conducted by comparing a CBO-led HIVST model with a CBO-led facility-based HIV rapid diagnostics testing (HIV-RDT) model. The full economic cost, including fixed and variable cost, from a health provider perspective using a micro costing approach was estimated. We determined the incremental cost-effectiveness ratios of these two HIV testing models over a 2-yeartime horizon (i.e. duration of the programs), and reported costs using US dollars (2021). RESULTS: From January 2017 to December 2018, a total of 4633 men were tested in the HIVST model, and 1780 men were tested in the HIV-RDT model. The total number of new diagnoses was 155 for HIVST and 126 for the HIV-RDT model; the HIV test positivity was 3.3% (95% confidence interval (CI): 2.8-3.9) for the HIVST model and 7.1% (95% CI: 5.9-8.4) for the HIV-RDT model. The mean cost per person tested was USD10.38 for HIVST and USD41.45 for HIV-RDT. The mean cost per diagnosed person was USD310.12 for HIVST compared with USD585.58 for HIV-RDT. CONCLUSION: Compared to facility-based HIV-RDT, a CBO-led HIVST program is cheaper and more effective among MSM living in China.

Simplified ex-vivo drug evaluation in ocular surface cells: Culture on cellulose filters of cells obtained by impression cytology.

Drug development, resource- and time-intensive, extensively employs cell-based assays to assess the efficacy and safety of candidate drugs. The widely used immortalized cell lines, experimentally convenient, have limited predictive value. In contrast, ex-vivo models more faithfully reproduce diseases but are technically challenging to establish. To address this need, we developed a simplified process for ex-vivo cell culture, demonstrating its feasibility in ocular surface cells. Conjunctival cells were harvested by impression cytology and grown on mixed cellulose ester membrane filters (MCFs). Human and rabbit conjunctival cells cultured on MCFs are 100% viable at 24 h, and 43% viable at 72 h. A gene expression study evaluating 84 genes involved in ocular inflammation demonstrated that ex-vivo culturing maintains intact the expression of two thirds of these genes in human cells. That these cells are suitable for the assessment of ocular drugs was demonstrated by studying the effect of phosphosulindac (PS), a small molecule under development for the treatment of dry eye disease, in both human and rabbit conjunctival cells. PS, for example, suppressed the expression of CXCL10, a cytokine participating in the pathogenesis of dry eye disease, in human and in rabbit conjunctival cells cultured ex-vivo by 32% and 70%, respectively. Conjunctival cells cultured ex-vivo can be transfected to evaluate mechanistic questions. We successfully transfected such cells with a plasmid expressing luciferase under the control of an IFN-γ-responsive promoter or its control plasmid. IFN-γ stimulated luciferase expression by 85% in cells with the responsive plasmid but not in controls; PS significantly suppressed this induction by 37% without affecting the control plasmid. These findings demonstrate that human and rabbit conjunctival cells cultured ex-vivo with our method are viable and maintain their biological integrity; respond to biological and pharmacological agents; and are transfectable with informative plasmids. The unique advantage of this method is to potentially accelerate the development of novel drugs for the treatment of ocular surface diseases, and to advance our understanding of ocular surface pathophysiology.

Maternal and fetal alkaline ceramidase 2 is required for placental vascular integrity in mice.

Sphingolipids have been implicated in mammalian placental development and function, but their regulation in the placenta remains unclear. Herein we report that alkaline ceramidase 2 (ACER2) plays a key role in sustaining the integrity of the placental vasculature by regulating the homeostasis of sphingolipids in mice. The mouse alkaline ceramidase 2 gene (Acer2) is highly expressed in the placenta between embryonic day (E) 9.5 and E12.5. Acer2 deficiency in both the mother and fetus decreases the placental levels of sphingolipids, including sphingoid bases (sphingosine and dihydrosphingosine) and sphingoid base-1-phosphates (sphingosine-1-phosphate and dihydrosphingosine-1-phosphate) and results in the in utero death of ≈50% of embryos at E12.5 whereas Acer2 deficiency in either the mother or fetus has no such effects. Acer2 deficiency causes hemorrhages from the maternal vasculature in the junctional and/or labyrinthine zones in E12.5 placentas. Moreover, hemorrhagic but not non-hemorrhagic Acer2-deficient placentas exhibit an expansion of parietal trophoblast giant cells with a concomitant decrease in the area of the fetal blood vessel network in the labyrinthine zone, suggesting that Acer2 deficiency results in embryonic lethality due to the atrophy of the fetal blood vessel network in the placenta. Taken together, these results suggest that ACER2 sustains the integrity of the placental vasculature by controlling the homeostasis of sphingolipids in mice.

Effectiveness of sexual health influencers identified by an ensemble machine learning model in promoting secondary distribution of HIV self-testing among men who have sex with men in China: study protocol for a quasi-experimental trial.

BACKGROUND: HIV self-testing (HIVST), especially the secondary distribution of HIVST (SD-HIVST) initiated by sexual health influencers (SHIs), has been recognized as an effective strategy in promoting HIV testing, especially among men who have sex with men (MSM). This quasi-experimental study aimed to evaluate whether SHIs identified through the ensemble machine learning approach can distribute more HIVST than those who identified by the empiricalscale. METHODS: We will recruit eligible adults (≥18 years old) who were assigned male gender at birth, and willing to participate in potential SD-HIVST online. Participants will be assigned randomly to two groups (scale group or machine learning group), followed by a separate process of SHI identification based on the group assignment. After identification, all index participants (defined as identified SHIs who are verbally consented to participate in SD-HIVST or who directly order HIVST kits) will follow the same procedure for SD-HIVST acquisition and distribution. Index participants can order HIVST online and distribute them to members within their social networks (defined as alters) in-person or virtually through a personalized peer referral link. Once a unique alter uploads a photographed test result to the platform, both the alter and the corresponding index participant will receive a fixed incentive of 3 USD. The index MSM can order up to five HIVST in the first three months and ten HIVST in the following three months. Each index participant will need to complete a baseline survey at the first-time ordering and one to two follow-upbased on the times of ordering,, three months after ordering. This trial will be comparing 1) the mean number of alters motivated by each index participant in each group and 2) the mean number of newly-tested alters motivated by each index participant in each group. DISCUSSION: In promoting the efficacy of identifying SHIs for SD-HIVST, our study has the potential to enhance testing coverage, particularly among marginalized individuals and those who are reluctant to for HIV and other sexually transmitted infections. TRIAL REGISTRATION: We registered the study on the Chinese Clinical Trial Registry website on 4th November 2021, with registration number ChiCTR2000039632 .

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OBJECTIVES: To analyze the differentially expressed genes (DEGs) with radiation-induced rat lung injury, and to reveal the protective mechanism for mild hypothermia in the radiation-induced lung injury in rats at the transcriptome level. METHODS: A total of 10 male SD rats aged 6-8 weeks were randomly divided into 2 groups to establish a rat model of radiation-induced lung injury, and one group was treated with mild hypothermia. RNA was extracted from left lung tissue of each group, and sequenced by BGISEQ-500 platform. Significance analysis of DEGs was carried out by edgeR software. Gene ontology (GO) function enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were used to analyze the gene function. Then 5 key DEGs were verified by real-time reverse transcription PCR (real-time RT-PCR). RESULTS: There were 2 790 DEGs (false discovery rate<0.001, |log2(fold change)|>1) in the mild hypothermia group compared with the model group, in which 2 257 genes were up-regulated and 533 genes were down-regulated. When real-time RT-PCR was used to validate the 5 key genes, the result was consistent with the RNA-seq. GO functional enrichment analysis showed that these DEGs were related to cell binding, metabolic process and cell membrane structure, etc. KEGG pathway enrichment analysis showed that these genes were involved in important biological pathways such as cell adhesion molecules, mammalian target of rapamycin, tight junction, and NF-κB. CONCLUSIONS: The DEGs and pathways related to mild hypothermia protection against radiation-induced lung injury in rats are obtained, which provides an experimental basis for the protection of mild hypothermia against radiation-induced lung injury.