Targeting KRAS Mutant Cancers with a Covalent G12C-Specific Inhibitor.

KRASG12C was recently identified to be potentially druggable by allele-specific covalent targeting of Cys-12 in vicinity to an inducible allosteric switch II pocket (S-IIP). Success of this approach requires active cycling of KRASG12C between its active-GTP and inactive-GDP conformations as accessibility of the S-IIP is restricted only to the GDP-bound state. This strategy proved feasible for inhibiting mutant KRAS in vitro; however, it is uncertain whether this approach would translate to in vivo. Here, we describe structure-based design and identification of ARS-1620, a covalent compound with high potency and selectivity for KRASG12C. ARS-1620 achieves rapid and sustained in vivo target occupancy to induce tumor regression. We use ARS-1620 to dissect oncogenic KRAS dependency and demonstrate that monolayer culture formats significantly underestimate KRAS dependency in vivo. This study provides in vivo evidence that mutant KRAS can be selectively targeted and reveals ARS-1620 as representing a new generation of KRASG12C-specific inhibitors with promising therapeutic potential.

A close quasar pair in a disk-disk galaxy merger at z = 2.17.

Galaxy mergers produce pairs of supermassive black holes (SMBHs), which may be witnessed as dual quasars if both SMBHs are rapidly accreting. The kiloparsec (kpc)-scale separation represents a physical regime sufficiently close for merger-induced effects to be important1 yet wide enough to be directly resolvable with the facilities currently available. Whereas many kpc-scale, dual active galactic nuclei-the low-luminosity counterparts of quasars-have been observed in low-redshift mergers2, no unambiguous dual quasar is known at cosmic noon (z ≈ 2), the peak of global star formation and quasar activity3,4. Here we report multiwavelength observations of Sloan Digital Sky Survey (SDSS) J0749 + 2255 as a kpc-scale, dual-quasar system hosted by a galaxy merger at cosmic noon (z = 2.17). We discover extended host galaxies associated with the much brighter compact quasar nuclei (separated by 0.46″ or 3.8 kpc) and low-surface-brightness tidal features as evidence for galactic interactions. Unlike its low-redshift and low-luminosity counterparts, SDSS J0749 + 2255 is hosted by massive compact disk-dominated galaxies. The apparent lack of stellar bulges and the fact that SDSS J0749 + 2255 already follows the local SMBH mass-host stellar mass relation, suggest that at least some SMBHs may have formed before their host stellar bulges. While still at kpc-scale separations where the host-galaxy gravitational potential dominates, the two SMBHs may evolve into a gravitationally bound binary system in around 0.22 Gyr.

Defect Engineering Centrosymmetric 2D Material Flexocatalysts.

In this study, the flexoelectric characteristics of 2D TiO2 nanosheets are examined. The theoretical calculations and experimental results reveal an excellent strain-induced flexoelectric potential (flexopotential) by an effective defect engineering strategy, which suppresses the recombination of electron-hole pairs, thus substantially improving the catalytic activity of the TiO2 nanosheets in the degradation of Rhodamine B dye and the hydrogen evolution reaction in a dark environment. The results indicate that strain-induced bandgap reduction enhances the catalytic activity of the TiO2 nanosheets. In addition, the TiO2 nanosheets degraded Rhodamine B, with kobs being ≈1.5 × 10-2 min-1 in dark, while TiO2 nanoparticles show only an adsorption effect. 2D TiO2 nanosheets achieve a hydrogen production rate of 137.9 µmol g-1 h-1 under a dark environment, 197% higher than those of TiO2 nanoparticles (70.1 µmol g-1 h-1 ). The flexopotential of the TiO2 nanosheets is enhanced by increasing the bending moment, with excellent flexopotential along the y-axis. Density functional theory is used to identify the stress-induced bandgap reduction and oxygen vacancy formation, which results in the self-dissociation of H2 O on the surface of the TiO in the dark. The present findings provide novel insights into the role of TiO2 flexocatalysis in electrochemical reactions.

Risk Factors and Nomogram Model for Hepatocellular Carcinoma Development in Chronic Hepatitis B Patients with Low-Level Viremia.

Background and aim: Patients with chronic hepatitis B patients (CHB) with low-level viremia (LLV) are not necessarily at low risk of developing hepatocellular carcinoma (HCC). The question of whether CHB patients with LLV require immediate antiviral agent (AVT) or long-term AVT remains controversial. The study aims to investigate the risk of HCC development and the risk factors in CHB patients with LLV and construct a nomogram model predicting the risk of HCC. Methods: We conducted a retrospective cohort study that enrolled 16,895 CHB patients from January 2008 to December 2020. The patients were divided into three groups for comparison: the LLV group, maintained virological response (MVR) group and HBV-DNA>2000 group. The cumulative incidence of progression to HCC was assessed. Cox regression analysis was performed to determine the final risk factors, and a nomogram model was constructed. The 10-fold Cross-Validation method was utilized for internal validation. Results: A total of 408 new cases of HCC occurred during the average follow-up period of 5.78 years. The 3, 5, and 10-year cumulative HCC risks in the LLV group were 3.56%, 4.96%, and 9.51%, respectively. There was a significant difference in the cumulative risk of HCC between the HBV-DNA level > 2000 IU/mL and LLV groups (p = 0.049). Independent risk factors for HCC development in LLV group included male gender, age, presence of cirrhosis, and platelets count. The Area Under the Curve (AUC) values for the 3-year and 5-year prediction from our HCC risk prediction model were 0.75 and 0.76, respectively. Conclusion: Patients with LLV and MVR are still at risk for developing HCC. The nomogram established for CHB patient with LLV, incorporating identified significant risk factors, serves as an effective tool for predicting HCC-free outcomes. This nomogram model provides valuable information for determining appropriate surveillance strategies and prescribing AVT.

Mechanical and biological properties of poly-ε-caprolactone membrane for pleurodesis: A preclinical study in pigs.

BACKGROUND/PURPOSE: Biomaterial implants are emerging as a treatment choice for pleurodesis; however, the optimal biomaterial and form for managing spontaneous pneumothorax, particularly post-video-assisted thoracic surgery, remain under investigation. This study evaluated the mechanical and biological properties of the poly-ε-caprolactone (PCL) membrane as a sclerosing agent for pleurodesis in Landrace pigs. METHODS: Twenty-four Landrace pigs were split into two groups for mechanical abrasion and PCL membrane pleurodesis, with the latter group's PCL meshes inserted using video-assisted thoracic surgery. The mechanical and biological properties of the PCL membrane were assessed in pigs at three, six, and 12 months after the procedure. This assessment involved a range of techniques, such as the T-Peel test, macroscopic evaluation with a scoring scale, microscopic examination, and biomechanical and molecular weight analysis. RESULTS: The PCL membrane group outperformed the traditional abrasion group, with stronger adhesions seen over longer implantation durations. This group also showed superior and more consistent results in both macroscopic and microscopic evaluations compared to the control group. The membrane-based method was easier and faster to perform than the control group's method, and importantly, no mortality occurred following membrane implantation. CONCLUSION: This study is the pioneering effort to present long-term findings regarding the mechanical and biological properties of the PCL membrane in an in vivo animal model. The membrane demonstrated better adhesion ability than that of traditional abrasion and showed reassuring biocompatibility in both the pig model, suggesting its potential as treatment for patients with primary spontaneous pneumothorax. Further clinical studies are needed to support these observations.

Pay-for-performance and continuity of care synergistically reduced amputation of lower extremity in patients with diabetes: a population-based cohort study.

BACKGROUND: Diabetic foot is a common and costly complication of diabetes. No existing study has looked at the effect of continuity of care on amputations of diabetes (DM) patients while considering pay-for-performance (P4P) participation. We investigated the impact of the P4P program and the continuity of care index (COCI) on the incidence of lower extremity amputations (LEA) among diabetics in Taiwan. METHODS: This was a population-based cohort study using insurance claims data from 1997 to 2013. We selected 15,650 DM patients in the P4P program along with age- and sex-matched non-P4P participants at a 1:4 ratio. Time-weighted average (TWA) of the COCI was calculated and included in the time-dependent Cox proportional hazard models to examine the impact of P4P and COCI on the risk of LEA, while controlling for individual and area level characteristics. RESULTS: During four-year follow-up, 1816 subjects experienced LEA. The cumulative LEA hazard rate of the P4P group (n = 153) was significantly lower than that of the non-P4P group (n = 1663) (hazard ratio = 0.37, 95% CI = 0.31-0.43, p < 0.0001, by log-rank test). In the time-dependent Cox proportional hazard model, the adjusted hazard ratios (aHR) for the P4P group was 0.35, (p < 0.0001). With the low COCI (< 0.360) group as the reference, the aHR of LEA was 0.49 (p < 0.0001) for the middle COCI group, (p < 0.0001), and the aHR of LEA for the high COCI (≥0.643) group was 0.23 (p < 0.0001). CONCLUSIONS: Participating in the P4P program and increasing COCI might reduce the risk of amputation for DM patients, independently and synergistically.

Prognostic Role of Subsequent Thrombocytopenia in Necrotizing Fasciitis Without Liver Disease.

BACKGROUND: Necrotizing fasciitis (NF) is a life-threatening disease with a fulminant presentation. Although early diagnosis can be aided by combining physical examination, the Laboratory Risk Indicator for Necrotizing Fasciitis score, and computed tomography, a mortality rate of 30% is still reported. In the modern times, an economical and efficient biomarker for predicting mortality in NF patients is still lacking. Platelet count is typically measured in routine blood tests and aids in predicting disease severity. We aimed to clarify the role of platelet count as a predictive factor for aspects of prognosis, such as mortality and surgical outcomes, in patients with NF. METHODS: We identified 285 patients with NF between 2018 and 2020 in a single medical center in southern Taiwan. Medical records were collected for the evaluation of patients with thrombocytopenia. Univariate and multivariate analyses were performed for different outcomes. RESULTS: We included 115 patients with confirmed diagnoses of NF. Twelve patients died with a mortality rate of 10.4%. Patients with thrombocytopenia exhibited a higher mortality rate (20.9% vs 4.2%, P = 0.006), more shock episodes (51.2% vs 11.1%, P < 0.001), higher intensive care unit admission rate (46.5% vs 13.9%, P < 0.001), and longer hospital length of stay (37.49 ± 24.12 days vs 28.82 ± 14.63 days, P = 0.037) than those without thrombocytopenia. All patients infected with Vibrio species exhibited thrombocytopenia. In multivariate analysis, independent risk factors for mortality were thrombocytopenia (odds ratio, 4.57; 95% confidence interval, 1.08-19.25) and single gram-negative bacterial culture from the wound (odds ratio 6.88; 95% confidence interval, 1.58-29.96). CONCLUSIONS: In patients with NF and subsequent thrombocytopenia, a higher mortality rate, greater numbers of shock episodes, higher demand for intensive care unit, and longer hospital length of stay were observed than in those without thrombocytopenia. In patients with NF, platelet count is a valuable and economic indicator of prognosis. Once thrombocytopenia developed in patients with necrotizing fasciitis, aggressive antibiotic treatment and surgical management are required to improve the chances of recovery.

Tumor location on MRI determines outcomes of patients with prostate cancer after total prostate cryoablation.

We investigated the association between tumor location on multiparametric magnetic resonance imaging (mpMRI) and outcomes of prostate cancer patients after primary total prostate cryoablation (PTPC). Between March 2010 and December 2012, consecutive 192 prostate cancer patients receiving PTPC were enrolled. Tumor locations were determined and classified as anterior apex (AA), anterior midgland (AM), anterior base (AB), posterior apex (PA), posterior midgland (PM) and posterior base (PB) using mpMRI. Midline location, central location, seminal vesicle invasion, extraprostatic extension, multiple tumors, and tumor volume were also identified. Prostate local recurrence and biochemical failure were considered as primary and secondary endpoints, respectively. Tumors on mpMRI were identified in 148 (77.1%) patients. Tumor locations were most frequently noted in PM (89, 46.4%), followed by AM (55, 28.6%), PB (53, 27.6%), PA (46, 24%), AA (35, 18.2%) and AB (31, 16.1%). Midline and central tumors were observed in 34 (17.7%) and 14 (7.3%) patients, respectively. During a median follow-up duration of 81 months (range, 2-114 months), 71 (37.0%) and 29 (40.8%) patients experienced biochemical failure and local recurrence, respectively. Multivariable analyses revealed only AA tumors increased the risk of local recurrences (HR = 2.98, 95% CI. 1.36-6.49). None of location-related parameters was associated with biochemical failure. Tumor location on mpMRI has a significant association with local tumor recurrence in patients receiving PTPC. Physicians should be cautious when conducting cryoablation for prostate tumors in AA location.

Mammography screening reduces rates of advanced and fatal breast cancers: Results in 549,091 women.

BACKGROUND: It is of paramount importance to evaluate the impact of participation in organized mammography service screening independently from changes in breast cancer treatment. This can be done by measuring the incidence of fatal breast cancer, which is based on the date of diagnosis and not on the date of death. METHODS: Among 549,091 women, covering approximately 30% of the Swedish screening-eligible population, the authors calculated the incidence rates of 2473 breast cancers that were fatal within 10 years after diagnosis and the incidence rates of 9737 advanced breast cancers. Data regarding each breast cancer diagnosis and the cause and date of death of each breast cancer case were gathered from national Swedish registries. Tumor characteristics were collected from regional cancer centers. Aggregated data concerning invitation and participation were provided by Sectra Medical Systems AB. Incidence rates were analyzed using Poisson regression. RESULTS: Women who participated in mammography screening had a statistically significant 41% reduction in their risk of dying of breast cancer within 10 years (relative risk, 0.59; 95% CI, 0.51-0.68 [P < .001]) and a 25% reduction in the rate of advanced breast cancers (relative risk, 0.75; 95% CI, 0.66-0.84 [P < .001]). CONCLUSIONS: Substantial reductions in the incidence rate of breast cancers that were fatal within 10 years after diagnosis and in the advanced breast cancer rate were found in this contemporaneous comparison of women participating versus those not participating in screening. These benefits appeared to be independent of recent changes in treatment regimens.

Association of Fenofibrate and Diabetic Retinopathy in Type 2 Diabetic Patients: A Population-Based Retrospective Cohort Study in Taiwan.

Background and Objectives: Fenofibrate, a PPAR-α agonist, has been demonstrated to reduce the progression of diabetic retinopathy (DR) and the need for laser treatment in a FIELD (Fenofibrate Intervention and Event Lowering in Diabetes) study. However, in the subgroup of patients without pre-existing DR, there was no significant difference in the progression of DR between the fenofibrate group and the placebo group. In this study, we aim to investigate whether fenofibrate can decrease the risk of incident DR in a population-based cohort study of type 2 diabetic patients in Taiwan. Materials and Methods: A total of 32,253 type 2 diabetic patients without previous retinopathy were retrieved from 892,419 patients in 2001-2002. They were then divided into two groups based on whether they were exposed to fenofibrate or not. The patients were followed until a diagnosis of diabetic retinopathy was made or until the year 2008. Results: With a follow-up period of 6.8 ± 1.5 years and 5.4 ± 2.6 years for 2500 fenofibrate users and 29,753 non-users, respectively, the Cox proportional hazard regression analysis revealed that the hazard ratio (HR) of new onset retinopathy was 0.57 (95% CI 0.57-0.62, p < 0.001). After adjusting for hypertension; the Charlson comorbidity index (CCI); and medications such as angiotensin-converting enzyme inhibitors (ACE-I), angiotensin receptor blockers (ARB), anticoagulants, gemfibrozil, statins, and hypoglycemic agents, the adjusted HR was 0.75 (95% CI 0.68-0.82, p < 0.001). The need for laser treatment has an HR and adjusted HR of 0.59 (95% CI 0.49-0.71, p < 0.001) and 0.67 (95% CI 0.56-0.81, p < 0.001), respectively. Conclusion: Our study showed that the long-term and regular use of fenofibrate may decrease the risk of incident retinopathy and the need for laser treatment in type 2 diabetic patients. Since there are limitations associated with our study, further investigations are necessary to confirm such an association.

The incidence of fatal breast cancer measures the increased effectiveness of therapy in women participating in mammography screening.

BACKGROUND: Women and their health care providers need a reliable answer to this important question: If a woman chooses to participate in regular mammography screening, then how much will this choice improve her chances of avoiding a death from breast cancer compared with women who choose not to participate? METHODS: To answer this question, we used comprehensive registries for population, screening history, breast cancer incidence, and disease-specific death data in a defined population in Dalarna County, Sweden. The annual incidence of breast cancer was calculated along with the annual incidence of breast cancers that were fatal within 10 and within 11 to 20 years of diagnosis among women aged 40 to 69 years who either did or did not participate in mammography screening during a 39-year period (1977-2015). For an additional comparison, corresponding data are presented from 19 years of the prescreening period (1958-1976). All patients received stage-specific therapy according to the latest national guidelines, irrespective of the mode of detection. RESULTS: The benefit for women who chose to participate in an organized breast cancer screening program was a 60% lower risk of dying from breast cancer within 10 years after diagnosis (relative risk, 0.40; 95% confidence interval, 0.34-0.48) and a 47% lower risk of dying from breast cancer within 20 years after diagnosis (relative risk, 0.53; 95% confidence interval, 0.44-0.63) compared with the corresponding risks for nonparticipants. CONCLUSIONS: Although all patients with breast cancer stand to benefit from advances in breast cancer therapy, the current results demonstrate that women who have participated in mammography screening obtain a significantly greater benefit from the therapy available at the time of diagnosis than do those who have not participated.

Dysregulated interactions between lamin A and SUN1 induce abnormalities in the nuclear envelope and endoplasmic reticulum in progeric laminopathies.

Hutchinson-Gilford progeria syndrome (HGPS) is a human progeroid disease caused by a point mutation on the LMNA gene. We reported previously that the accumulation of the nuclear envelope protein SUN1 contributes to HGPS nuclear aberrancies. However, the mechanism by which interactions between mutant lamin A (also known as progerin or LAΔ50) and SUN1 produce HGPS cellular phenotypes requires further elucidation. Using light and electron microscopy, this study demonstrated that SUN1 contributes to progerin-elicited structural changes in the nuclear envelope and the endoplasmic reticulum (ER) network. We further identified two domains through which full-length lamin A associates with SUN1, and determined that the farnesylated cysteine within the CaaX motif of lamin A has a stronger affinity for SUN1 than does the lamin A region containing amino acids 607 to 656. Farnesylation of progerin enhanced its interaction with SUN1 and reduced SUN1 mobility, thereby promoting the aberrant recruitment of progerin to the ER membrane during postmitotic assembly of the nuclear envelope, resulting in the accumulation of SUN1 over consecutive cellular divisions. These results indicate that the dysregulated interaction of SUN1 and progerin in the ER during nuclear envelope reformation determines the progression of HGPS.

AZD1208, a potent and selective pan-Pim kinase inhibitor, demonstrates efficacy in preclinical models of acute myeloid leukemia.

Upregulation of Pim kinases is observed in several types of leukemias and lymphomas. Pim-1, -2, and -3 promote cell proliferation and survival downstream of cytokine and growth factor signaling pathways. AZD1208 is a potent, highly selective, and orally available Pim kinase inhibitor that effectively inhibits all three isoforms at <5 nM or <150 nM in enzyme and cell assays, respectively. AZD1208 inhibited the growth of 5 of 14 acute myeloid leukemia (AML) cell lines tested, and sensitivity correlates with Pim-1 expression and STAT5 activation. AZD1208 causes cell cycle arrest and apoptosis in MOLM-16 cells, accompanied by a dose-dependent reduction in phosphorylation of Bcl-2 antagonist of cell death, 4EBP1, p70S6K, and S6, as well as increases in cleaved caspase 3 and p27. Inhibition of p4EBP1 and p-p70S6K and suppression of translation are the most representative effects of Pim inhibition in sensitive AML cell lines. AZD1208 inhibits the growth of MOLM-16 and KG-1a xenograft tumors in vivo with a clear pharmacodynamic-pharmacokinetic relationship. AZD1208 also potently inhibits colony growth and Pim signaling substrates in primary AML cells from bone marrow that are Flt3 wild-type or Flt3 internal tandem duplication mutant. These results underscore the therapeutic potential of Pim kinase inhibition for the treatment of AML.

Risk of Autoimmune Disease in Adults with Chronic Insomnia Requiring Sleep-Inducing Pills: A Population-Based Longitudinal Study.

BACKGROUND: Recent studies indicate that chronic insomnia is associated with the development of certain somatic diseases. Whether it would be associated with the development of an autoimmune disease (AID) was unknown. OBJECTIVE: We aimed to examine the association and quantify the magnitude of risk for AID in individuals suffering from chronic insomnia requiring sleep-inducing pills. DESIGN: This was a population-based, nationwide longitudinal study. PARTICIPANTS: Using a claims data set containing 1 million randomly sampled, insured subjects derived from the National Health Insurance Research Database, we assembled a chronic insomnia group and a 1:3 propensity score-matched comparison group (CP), which were balanced in terms of sex, age, insurance premium, urbanization, alcohol use disorder, smoking-related diagnoses, and morbid obesity. MAIN MEASURES: Person-time data with incidence rate, adjusted hazard ratios (aHR) by the Cox model, AID-free survival functions compared with the log-rank test, and a sensitivity analysis on the time lag effect were presented. Incident AID within the first year of follow-up were excluded. The error rate was controlled using the Benjamini-Hochberg procedure. KEY RESULTS: With 39,550 and 129,914 person-years' follow-up for the chronic insomnia and CP groups (n = 5,736 and 17,208), respectively, we found an increased risk for subsequent AID, representing a 70 % increase in the aHR (1.7; 95 % confidence interval [CI], 1.5-1.9, p < 0.0001). A positive association between chronic insomnia and primary Sjögren's syndrome (pSS) was observed (aHR, 1.3; 95 % CI, 1.1-1.6). Sensitivity analysis disclosed that AID risk was even stronger after 5 years of follow-up (aHR, 2.0; 95 % CI, 1.7-2.4). CONCLUSION: Chronic insomnia requiring sleep-inducing pills may be associated with a 70 % increased risk for future AID, particularly pSS.

Finding a Potential Dipeptidyl Peptidase-4 (DPP-4) Inhibitor for Type-2 Diabetes Treatment Based on Molecular Docking, Pharmacophore Generation, and Molecular Dynamics Simulation.

Dipeptidyl peptidase-4 (DPP-4) is the vital enzyme that is responsible for inactivating intestinal peptides glucagon like peptide-1 (GLP-1) and Gastric inhibitory polypeptide (GIP), which stimulates a decline in blood glucose levels. The aim of this study was to explore the inhibition activity of small molecule inhibitors to DPP-4 following a computational strategy based on docking studies and molecular dynamics simulations. The thorough docking protocol we applied allowed us to derive good correlation parameters between the predicted binding affinities (pKi) of the DPP-4 inhibitors and the experimental activity values (pIC50). Based on molecular docking receptor-ligand interactions, pharmacophore generation was carried out in order to identify the binding modes of structurally diverse compounds in the receptor active site. Consideration of the permanence and flexibility of DPP-4 inhibitor complexes by means of molecular dynamics (MD) simulation specified that the inhibitors maintained the binding mode observed in the docking study. The present study helps generate new information for further structural optimization and can influence the development of new DPP-4 inhibitors discoveries in the treatment of type-2 diabetes.

Epstein-Barr virus BALF3 has nuclease activity and mediates mature virion production during the lytic cycle.

UNLABELLED: Epstein-Barr virus (EBV) lytic replication involves complex processes, including DNA synthesis, DNA cleavage and packaging, and virion egress. These processes require many different lytic gene products, but the mechanisms of their actions remain unclear, especially for DNA cleavage and packaging. According to sequence homology analysis, EBV BALF3, encoded by the third leftward open reading frame of the BamHI-A fragment in the viral genome, is a homologue of herpes simplex virus type 1 UL28. This gene product is believed to possess the properties of a terminase, such as nucleolytic activity on newly synthesized viral DNA and translocation of unit length viral genomes into procapsids. In order to characterize EBV BALF3, the protein was produced by and purified from recombinant baculoviruses and examined in an enzymatic reaction in vitro, which determined that EBV BALF3 acts as an endonuclease and its activity is modulated by Mg(2+), Mn(2+), and ATP. Moreover, in EBV-positive epithelial cells, BALF3 was expressed and transported from the cytoplasm into the nucleus following induction of the lytic cycle, and gene silencing of BALF3 caused a reduction of DNA packaging and virion release. Interestingly, suppression of BALF3 expression also decreased the efficiency of DNA synthesis. On the basis of these results, we suggest that EBV BALF3 is involved simultaneously in DNA synthesis and packaging and is required for the production of mature virions. IMPORTANCE: Virus lytic replication is essential to produce infectious virions, which is responsible for virus survival and spread. This work shows that an uncharacterized gene product of the human herpesvirus Epstein-Barr virus (EBV), BALF3, is expressed during the lytic cycle. In addition, BALF3 mediates an endonucleolytic reaction and is involved in viral DNA synthesis and packaging, leading to influence on the production of mature virions. According to sequence homology and physical properties, the lytic gene product BALF3 is considered a terminase in EBV. These findings identify a novel viral gene with an important role in contributing to a better understanding of the EBV life cycle.

Transforming growth factor-ß1 up-regulates connexin43 expression in human granulosa cells.

STUDY QUESTION: Does transforming growth factor-ß1 (TGF-ß1) up-regulate connexin43 (Cx43) to promote cell-cell communication in human granulosa cells? SUMMARY ANSWER: TGF-ß1 up-regulates Cx43 and increases gap junction intercellular communication activities (GJIC) in human granulosa cells, and this effect occurs via the activin receptor-like kinase (ALK)5-mediated Sma- and Mad-related protein (SMAD)2/3-SMAD4-dependent pathway. WHAT IS KNOWN ALREADY: TGF-ß1 and its receptors are expressed in human granulosa cells, and follicular fluid contains TGF-ß1 protein. In human granulosa cells, Cx43 gap junctions play an important role in the development of follicles and oocytes. STUDY DESIGN, SIZE, DURATION: This is an experimental study which was performed over a 1-year period. PARTICIPANTS/MATERIALS, SETTING, METHODS: Immortalized human granulosa cells (SVOG cells) and primary human granulosa-lutein cells obtained from women undergoing IVF in an academic research center were used as the study models. Cx43 mRNA and protein expression levels were examined after exposure of SVOG cells to recombinant human TGF-ß1. An activin/TGF-ß type I receptor inhibitor, SB431542, and small interfering RNAs targeting ALK4, ALK5, SMAD2, SMAD3 and SMAD4 were used to verify the specificity of the effects and to investigate the molecular mechanisms. Real-time-quantitative PCR and western blot analysis were used to detect the specific mRNA and protein levels, respectively. GJIC between SVOG cells were evaluated using a scrape loading and dye transfer assay. Results were analyzed by one-way analysis of variance. MAIN RESULTS AND THE ROLE OF CHANCE: TGF-ß1 treatment increased phosphorylation of SMAD2/3 (P < 0.0001) and up-regulated Cx43 mRNA and protein levels (P < 0.001) in SVOG cells and these stimulatory effects were abolished by the TGF-ß type I receptor inhibitor SB431542. In addition, the up-regulatory effect of TGF-ß1 on Cx43 expression (mRNA and protein) was confirmed in primary cultures of human granulosa-lutein cells (P < 0.05). The small interfering RNA-mediated knockdown of ALK5, but not ALK4, abolished the TGF-ß1-induced phosphorylation of SMAD2/3 and the up-regulation of Cx43. Furthermore, knockdown of SMAD2/3 or the common SMAD, SMAD4, abolished the stimulatory effects of TGF-ß1 on Cx43 expression in SVOG cells. The TGF-ß1-induced up-regulation of Cx43 contributed to the increase of GJIC between SVOG cells (P < 0.001). LIMITATIONS, REASONS FOR CAUTION: The results of this study were generated from in vitro system and may not reflect the intra-ovarian microenvironment in vivo. WIDER IMPLICATIONS OF THE FINDINGS: Our studies represent the first comprehensive research of molecular mechanisms of TGF-ß1 in the regulation of Cx43 expression and GJIC in human granulosa cells and demonstrate that TGF-ß1 may play a crucial role in the local modulation of cell-cell communication. Deepening our understanding of the molecular determinants will offer important insights into ovarian physiology and lead to the development of potential therapeutic methods for fertility regulation. STUDY FUNDING/COMPETING INTERESTS: This research was supported by an operating grant from the Canadian Institutes of Health Research to P.C.K.L. There are no conflicts of interest to declare. TRIAL REGISTRATION NUMBER: NA.

Crystal amphetamine smoking-induced acute eosinophilic pneumonia and diffuse alveolar damage: a case report and literature review.

Eosinophilic pneumonia (EP) is a disease characterized by prominent infiltration of lung structures by eosinophils. The lung interstitium is infiltrated by eosinophils, and essentially the alveolar spaces are filled with eosinophils and a fibrinous exudate, with conservation of the global architecture of the lung. Diagnosis of EP relies on pathological demonstration of alveolar eosinophilia along with characteristic clinical manifestations of nonproductive cough, dyspnea, chest pain and/or unique imaging features. EP may be categorized according to the origin: EP of undetermined origin may overlap with well-individualized syndromes, while EP with a definite cause are mainly due to infections or drug abuse. Here, we report a case of an amphetamine abuser who developed acute EP and acute respiratory distress syndrome after amphetamine inhalation. Related studies on the pathogenesis of stimulant-related lung injury and treatment strategies are also discussed.

Uncovering the Roles of Mycobacterium tuberculosis melH in Redox and Bioenergetic Homeostasis: Implications for Antitubercular Therapy.

Mycobacterium tuberculosis ( Mtb ), the pathogenic bacterium that causes tuberculosis, has evolved sophisticated defense mechanisms to counteract the cytotoxicity of reactive oxygen species (ROS) generated within host macrophages during infection. The melH gene in Mtb and Mycobacterium marinum ( Mm ) plays a crucial role in defense mechanisms against ROS generated during infection. We demonstrate that melH encodes an epoxide hydrolase and contributes to ROS detoxification. Deletion of melH in Mm resulted in a mutant with increased sensitivity to oxidative stress, increased accumulation of aldehyde species, and decreased production of mycothiol and ergothioneine. This heightened vulnerability is attributed to the increased expression of whiB3 , a universal stress sensor. The absence of melH also resulted in reduced intracellular levels of NAD + , NADH, and ATP. Bacterial growth was impaired, even in the absence of external stressors, and the impairment was carbon-source-dependent. Initial MelH substrate specificity studies demonstrate a preference for epoxides with a single aromatic substituent. Taken together, these results highlight the role of melH in mycobacterial bioenergetic metabolism and provide new insights into the complex interplay between redox homeostasis and generation of reactive aldehyde species in mycobacteria. Importance: This study unveils the pivotal role played by the melH gene in Mycobacterium tuberculosis and Mycobacterium marinum in combatting the detrimental impact of oxidative conditions during infection. This investigation revealed notable alterations in the level of cytokinin-associated aldehyde, para -hydroxybenzaldehyde, as well as the redox buffer ergothioneine, upon deletion of melH . Moreover, changes in crucial cofactors responsible for electron transfer highlighted melH 's crucial function in maintaining a delicate equilibrium of redox and bioenergetic processes. MelH prefers epoxide small substrates with a phenyl substituted substrate. These findings collectively emphasize the potential of melH as an attractive target for the development of novel antitubercular therapies that sensitize mycobacteria to host stress, offering new avenues for combating tuberculosis.