Prospective Study of Homologous Recombination Repair Gene Mutation Prevalence in Patients With Advanced Prostate Cancer From Latin America: Challenges and Future Approaches.

PURPOSE: The prevalence of homologous recombination repair gene mutations (HRRm) in patients with metastatic castration-resistant prostate cancer (mCRPC) in Latin America and the Caribbean (LAC) is unknown. Prevalence of homologous Recombination repair (HRR) gene mutatiOns in patientS with metastatic castration resistant ProstatE Cancer in LaTin America (PROSPECT) aimed to determine this prevalence and to describe the demographic and clinical characteristics of the participants. MATERIALS AND METHODS: This was a prospective, cross-sectional, multicenter study across 11 cancer centers in seven LAC countries. After informed consent, all eligible participants underwent genomic testing by provided blood samples for germline HRR testing; they also provided PC tissue blocks if available for somatic HRR testing. RESULTS: Between April 2021 and April 2022, 387 patients (median age, 70 years [49-89], 94.3% Eastern Cooperative Oncology Group 0-1) with mCRPC were enrolled in the study. Almost 40% of them had a family history of cancer, and the overall time from their initial PC and mCRPC diagnosis was 3 years and 1 year, respectively. The overall prevalence of germline HRRm was 4.2%. The mutations detected included the genes CHEK2 (n = 4, 1%), ATM (n = 3, 0.8%), BRCA2 (n = 3, 0.8%), BRIP1 (n = 2, 0.5%), RAD51B (n = 2, 0.5%), BRCA1 (n = 1, 0.3%), and MRE11 (n = 1, 0.3%). The prevalence of somatic HRRm could not be assessed because of high HRR testing failure rates (79%, 199/251) associated with insufficient DNA, absence of tumor cells, and poor-quality DNA. CONCLUSION: Despite the study's limitations, to our knowledge, PROSPECT was the first attempt to describe the prevalence of HRRm in patients with PC from LAC. Notably, the germline HRRm prevalence in this study was inferior to that observed in North American and European populations. The somatic HRR testing barriers identified are being addressed by several projects to improve access to HRR testing and biomarker-based therapies in LAC.

Simulations of Multifocal Vision in Patients With Previous Monofocal Intraocular Lens Implantation.

PURPOSE: To evaluate the effectiveness and patient acceptance of multifocal vision simulation in patients with previous monofocal intraocular lens (IOL) implantation, and to explore their willingness-to-pay (WTP) and willingness-to-accept (WTA) based on the perceived advantages and disadvantages of multifocal vision. METHODS: Seventeen patients with previous monofocal IOL implantation participated in this cross-sectional study. The SimVis Gekko device (2EyesVision SL) was used to simulate monofocal (Evaluation B) and multifocal (Evaluation C) visual experiences, compared to their existing vision (Evaluation A). Visual acuity at three distances and defocus curves were measured. Patients responded to inquiries about visual quality in each evaluation, bothersomeness of photic phenomena, probability to select the visual experience, and the monetary value they associated with enhanced WTP or diminished WTA visual quality. RESULTS: The simulations underestimated the visual acuity reported for the IOL in existing literature by one or two lines, depending on the testing distance. This underestimation was more pronounced in defocus curves. However, 70.6% of patients were likely or very likely to opt for multifocal vision, indicating they perceived the benefits of multifocality. The WTP for multifocal vision was twice that of monofocal vision, and the WTP/WTA ratio exceeded 1, suggesting the perceived vision benefits outweighed potential drawbacks. CONCLUSIONS: Despite underestimating the expected postoperative visual performance, the multifocal simulation enabled patients to perceive the benefits of multifocal vision to some extent. This system could be beneficial in avoiding potential postoperative complaints, but the possible rise in false-positive results should be considered and evaluated in future research. [J Refract Surg. 2023;39(12):831-839.].

The effect of vitrification on blastocyst mitochondrial DNA dynamics and gene expression profiles.

PURPOSE: Does vitrification/warming affect the mitochondrial DNA (mtDNA) content and the gene expression profile of blastocysts? METHODS: Prospective cohort study in which 89 blastocysts were obtained from 50 patients between July 2017 and August 2018. mtDNA was measured in a total of 71 aneuploid blastocysts by means of real-time polymerase chain reaction (RT-PCR). Transcriptomic analysis was performed by RNA sequencing (RNA-seq) in an additional 8 aneuploid blastocysts cultured for 0 h after warming, and 10 aneuploid blastocysts cultured for 4-5 h after warming. RESULTS: A significant decrease in mtDNA content just during the first hour after the warming process in blastocysts was found (P < 0.05). However, mtDNA content experimented a significantly increased along the later culture hours achieving the original mtDNA levels before vitrification after 4-5 h of culture (P < 0.05). Gene expression analysis and functional enrichment analysis revealed that such recovery was accompanied by upregulation of pathways associated with embryo developmental capacity and uterine embryo development. Interestingly, the significant increase in mtDNA content observed in blastocysts just after warming also coincided with the differential expression of several cellular stress response-related pathways, such as apoptosis, DNA damage, humoral immune responses, and cancer. CONCLUSION: To our knowledge, this is the first study demonstrating in humans, a modulation in blastocysts mtDNA content in response to vitrification and warming. These results will be useful in understanding which pathways and mechanisms may be activated in human blastocysts following vitrification and warming before a transfer.

Exploring the Protective Efficacy of Topical Products for Actinic Keratosis Against Ultraviolet-Induced DNA and Protein Damage: An Experimental, Double-Blind Irradiation Study.

Introduction Numerous studies have delved into the clinical efficacy of different topical treatments for actinic keratosis (AK). However, our understanding remains limited regarding their capacity to prevent DNA and protein damage caused by ultraviolet radiation (UVR). Objectives The aim of this study was to analyze and compare the preventive capabilities of various AK-targeted products in countering DNA and protein alterations in human biopsies following exposure to experimental UVR. Methods Twelve healthy Caucasian volunteers (six men and six women) aged 18 years and above, with Fitzpatrick skin types II-III, participated in an experimental irradiation study. Six topical products, containing various ingredients (DNA repair enzymes, antioxidants, keratolytic agents, cyclooxygenase inhibitors, and/or sunscreens) were tested. The experimental sites were exposed to UVR at six times the minimal erythema dose for eight consecutive days. Each test product was applied 30 to 45 minutes before irradiation at a standard thickness of 2 mg/cm2. A control site was treated with the vehicle alone, serving as a negative control. The study focused on cyclobutane pyrimidine dimers (CPDs) and protein carbonylation (PC) as molecular markers of UVR-induced DNA and protein damage, respectively. Results The efficacy of different AK-targeted topical products showed substantial variation when applied to normal skin before experimental exposure to UVR. While sunscreens, predictably, played a crucial role, additional ingredients (i.e., DNA repair enzymes and antioxidants) also acted as vital protective agents for both the cellular genome and proteome, shielding them against UVR-induced damage. Conclusion In topical products specifically designed for AK, the strategic integration of DNA repair enzymes and antioxidants, in addition to sunscreens, establishes a critical defense mechanism against the detrimental effects of UVR on cellular DNA and proteins.

Impact of different job types on serum cytokine levels in apparently healthy individuals: A comparative study among airline pilots, construction workers, and fitness instructors.

BACKGROUND: The impact of occupational factors on serum cytokine concentrations has not been extensively explored. In this preliminary investigation, we measured the amounts of 12 cytokines in the serum of healthy individuals, comparing three diverse professional categories (aviation pilots, building laborers, and exercise trainers) with distinct work settings and lifestyle factors. METHODS: The study sample comprised 60 men from three distinct professional fields - airline pilots, construction laborers, and fitness trainers (20 participants per category) - who were enlisted during regular outpatient occupational health appointments. Serum levels of interleukin (IL)-1ß, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12p70, IL-17, tumor necrosis factor (TNF)-α, interferon (IFN)-α, and IFN-γ were measured on a Luminex® platform using a specific kit. Cytokine levels were compared among the three professional groups to determine any significant differences. RESULTS: Among the three occupational groups, fitness instructors demonstrated elevated IL-4 concentrations in comparison to both airline pilots and construction laborers, with no significant difference between the latter two professions. Additionally, a stepwise increase in IL-6 levels was identified, commencing with fitness instructors presenting the lowest quantities, succeeded by construction workers, and culminating with airline pilots, who displayed the most elevated concentrations. CONCLUSION: Serum cytokine levels in healthy individuals can exhibit variations based on their occupation. Given the unfavorable cytokine profile detected in airline pilots, it is crucial for the aviation sector to tackle potential health concerns within their employees.

Should embryo rebiopsy be considered a regular strategy to increase the number of embryos available for transfer?

PURPOSE: To investigate whether embryo rebiopsy increases the yield of in vitro fertilization (IVF) cycles. METHODS: Retrospective study including 18,028 blastocysts submitted for trophectoderm biopsy and preimplantation genetic testing for aneuploidy (PGT-A) between January 2016 and December 2021 in a private IVF center. Out of the 517 embryos categorized as inconclusive, 400 survived intact to the warming procedure, re-expanded, and were suitable for rebiopsy. Of them, 71 rebiopsied blastocysts were transferred. Factors affecting the probability of obtaining an undiagnosed blastocyst and clinical outcomes from blastocysts biopsied once and twice were investigated. RESULTS: The overall diagnostic rate was 97.1%, with 517 blastocysts receiving inconclusive reports. Several blastocyst and laboratory features, such as the day of the biopsy, the stage of development, and the biopsy methodology, were related to the risk of obtaining an inconclusive diagnosis after PGT-A. A successful diagnosis was obtained in 384 of the rebiopsied blastocysts, 238 of which were chromosomally transferable. A total of 71 rebiopsied blastocysts were transferred, resulting in 32 clinical pregnancies [(clinical pregnancy rate (CPR)=45.1%], 16 miscarriages [(miscarriage rate (MR)=41%], and, until September 2020, 12 live births [(live birth rate (LBR)=23.1%]. A significantly lower LBR and higher MR were obtained after transferring rebiopsied blastocysts compared to those biopsied once. CONCLUSION: Although an extra round of biopsy and vitrification may cause a detrimental effect on embryo viability, re-analyzing the test-failure blastocysts contributes to increasing the number of euploid blastocysts available for transfer and the LBR.

Disparities in refusal of surgery for gynecologic cancer.

OBJECTIVE: To identify sociodemographic and clinical factors associated with refusal of gynecologic cancer surgery and to estimate its effect on overall survival. METHODS: The National Cancer Database was surveyed for patients with uterine, cervical or ovarian/fallopian tube/primary peritoneal cancer treated between 2004 and 2017. Univariate and multivariate logistic regression were used to assess associations between clinico-demographic variables and refusal of surgery. Overall survival was estimated using the Kaplan-Meier method. Trends in refusal over time were evaluated using joinpoint regression. RESULTS: Of 788,164 women included in our analysis, 5875 (0.75%) patients refused surgery recommended by their treating oncologist. Patients who refused surgery were older at diagnosis (72.4 vs 60.3 years, p < 0.001) and more likely Black (OR 1.77 95% CI 1.62-1.92). Refusal of surgery was associated with uninsured status (OR 2.94 95% CI 2.49-3.46), Medicaid coverage (OR 2.79 95% CI 2.46-3.18), low regional high school graduation (OR 1.18 95% CI 1.05-1.33) and treatment at a community hospital (OR 1.59 95% CI 1.42-1.78). Patients who refused surgery had lower median overall survival (1.0 vs 14.0 years, p < 0.01) and this difference persisted across disease sites. Between 2008 and 2017, there was a significant increase in refusal of surgery annually (annual percent change +1.41%, p < 0.05). CONCLUSIONS: Multiple social determinants of health are independently associated with refusal of surgery for gynecologic cancer. Given that patients who refuse surgery are more likely from vulnerable, underserved populations and have inferior survival, refusal of surgery should be considered a surgical healthcare disparity and tackled as such.

Palliative Medicine Referral and End-of-Life Interventions Among Racial and Ethnic Minority Patients With Advanced or Recurrent Gynecologic Cancer.

BACKGROUND: Referral to palliative medicine (PM) has been shown to improve quality of life, reduce hospitalizations, and improve survival. Limited data exist about PM utilization among racial minorities with gynecologic malignancies. Our objective was to assess differences in palliative medicine referrals and end of life interventions (within the last 30 days of life) by race and ethnicity in a diverse population of gynecologic oncology patients. METHODS: A retrospective cohort study of patients receiving gynecologic oncologic care at a tertiary referral center between 2017 - 2019 was conducted. Patients had either metastatic disease at the time of diagnosis or recurrence. Demographic and clinical data were abstracted. Exploratory analyses were done using chi-square and rank sum tests. Tests were two-sided with significance set at P < .05. RESULTS: A total of 186 patients were included. Of those, 82 (44.1%) were referred to palliative medicine. Underrepresented minorities accounted for 47.3% of patients. English was identified as the primary language for 69.9% of the patients and Spanish in 24.2%. Over 90% of patients had insurance coverage. Ovarian cancer (37.6%) and uterine cancer (32.8%) were the most common sites of origin. Most patients (75%) had advanced stage at the time of diagnosis. Race and language spoken were not associated with referral to PM. Black patients were more likely to have been prescribed appetite stimulants compared to White patients (41% vs 24%, P = .038). Black patients also had a higher number of emergency department visits compared to White patients during the study timeframe. Chemotherapy in the last 30 days of life was also more likely to be given to Black patients compared to White (P = .019). CONCLUSIONS: Race was associated with variation in interventions and healthcare utilization near end-of-life. Understanding the etiologies of these differences is crucial to inform interventions for care optimization as it relates specifically to the health of minority patients.

Immediate adverse reactions in the chemotherapy treatment of patients with cancer at an oncology day hospital.

A descriptive and cross-sectional study was performed to characterize the degree of immediate adverse reaction and the type of causative antineoplastic drug presented by 371 different patients treated for cancer at the oncology day hospital unit of the San Carlos Clinical Hospital (Madrid, Spain), during the period between January 2015 and December 2019. In the case series, 488 immediate adverse reactions secondary to chemotherapy toxicity were detected. The dominating factors were: Female sex, age from 51-70 years old, skin melanoma and the use of vinca alkaloids and analogs. Among the most frequent adverse reactions, the following stood out: Disorders of the nervous and musculoskeletal systems and of the connective tissue. There was a higher number of moderate adverse reactions (grade 2 according to the Common Terminology Criteria for Adverse Events Version 4.0) between the first and third chemotherapy cycles, with a latency period of between 6 and 15 min., generally lasting less than 30 min. Association with the degree of immediate adverse reaction (grade) has been observed in male subjects over 71 years of age, with soft tissue neoplasm type and monoclonal antibodies therapeutic group.

Increased Peripheral Blood DNA Damage and Elevated Serum Levels of Melanoma Inhibitory Activity Protein: Clues to Excess Skin Cancer Risk in Airline Pilots?

Background and objective The risk of malignant melanoma (MM) and other forms of skin cancer appears to be higher in airline pilots (APs), potentially due to their exposure to ionizing and ultraviolet (UV) radiation. We explored the possibility of increased peripheral blood DNA damage and elevated serum levels of the melanoma inhibitory activity (MIA) protein - a serological marker for MM known to be stimulated by UV radiation - in this professional group. Methods This was a case-control study involving 40 male APs, each of whom was age- and tenure-matched (≥5 years of service) with 40 male office workers (OWs). We assessed DNA damage in the two professional groups by performing comet and micronucleus (MN) assays on peripheral blood. Serum levels of MIA protein were quantified using an immunoassay. Results The comet tail lengths and the frequency of MN were significantly higher in APs (4.57 ± 0.79 µm and 2.05 ± 0.26 per 1000 cells, respectively) than in OWs (3.81 ± 0.60 µm and 1.76 ± 0.31 per 1000 cells, respectively, both p<0.001). Furthermore, serum MIA levels were also significantly higher in APs (7.45 ± 0.95 ng/mL) than in OWs (5.78 ± 0.54 ng/mL, p<0.001). A significant positive correlation was found between comet tail lengths in APs and their serum MIA concentrations (r=0.68, p<0.01). Conclusions The increased burden of DNA damage and elevated serum MIA levels in APs may offer an explanation for their higher susceptibility to MM and other types of skin cancers.

Skin biophysical parameters and serum dermokine levels in airline pilots: a comparative study with office workers.

Introduction: Concerns are growing in the aviation industry about occupational skin diseases like malignant melanoma (MM) among airline pilots (APs), due to the unique working environment that exposes them to various skin stressors. Aim: To compare five skin biophysical parameters in a group of 40 male APs, each matched in terms of age and service tenure (minimum of 5 years) with a control group of 40 male office workers (OWs). Considering the potential role of dermokine (DMKN) in skin barrier dysfunction and the pathogenesis of MM, we further analyzed the serum levels of this molecule and correlated them with the measured skin parameters. Material and methods: Stratum corneum skin hydration, transepidermal water loss (TEWL), sebum content, erythema index (EI), and melanin index (MI) were quantified by non-invasive instruments in the cheek region. Serum DMKN levels were measured using a commercially available enzyme-linked immunosorbent assay kit. Results: Compared with OWs, the skin of APs exhibited a decrease in hydration levels in the stratum corneum, coinciding with a higher TEWL. However, there was no significant variance in sebum content between the groups. MI was notably higher in APs than in OWs, as was EI. In APs, serum DMKN levels were independently associated with MI (ß = 0.56, p < 0.05). Conclusions: We found a significant link between the profession of an airline pilot and changes in skin biophysical parameters. Further research into the interplay between serum DMKN levels and the risk of MM in APs is warranted.

A Comparative Study of Seroprevalence of 17 Common Pathogens Among Airline Pilots and Office Workers.

Background The variation in infection risk among individuals is thought to be partially influenced by occupational factors. This study aims to investigate the seropositivity rates of 17 common infectious agents in male airline pilots (APs), a professional group known to experience a high prevalence of cardiovascular and gastrointestinal diseases. Methodology In our study, we employed a case-control design with 100 male APs as cases, matched by age, sex, and tenure (i.e., at least five years of service) to 100 male office workers (OWs) who served as controls. We measured the IgG antibody levels to 17 pathogens using specific enzyme-linked immunosorbent assays, including herpes simplex virus 1, herpes simplex virus 2, varicella-zoster virus, Epstein-Barr virus, cytomegalovirus, human herpesvirus 6, human herpesvirus 7, Kaposi's sarcoma-associated herpesvirus, Toxoplasma gondii, human T-lymphotropic virus 1, BK virus, John Cunningham virus, Merkel cell polyomavirus, human papillomavirus 16, human papillomavirus 18, Chlamydia trachomatis, and Helicobacter pylori. The determination of seropositivity cutoffs for each pathogen was made in accordance with the guidelines provided by the respective kit manufacturers. Results The seropositivity rates for the 17 pathogens ranged from 1% for human T-lymphotropic virus 1 to 94% for varicella-zoster virus and were similar in both professions, except for herpes simplex virus 1 and Helicobacter pylori, which were more prevalent in APs. Conclusions Our findings suggest a higher prevalence of previous infections with herpes simplex virus 1 and Helicobacter pylori in APs compared to OWs. These infections may be associated with the prevalence of specific non-communicable diseases in this professional group. However, additional longitudinal studies are needed to substantiate this hypothesis.

Systemic Immune Profile Predicts the Development of Infections in Patients with Spinal Cord Injuries.

Patients with spinal cord injury (SCI) frequently develop infections that may affect quality of life, be life-threatening, and impair their neurological recovery in the acute and subacute injury phases. Therefore, identifying patients with SCI at risk for developing infections in this stage is of utmost importance. We determined the systemic levels of immune cell populations, cytokines, chemokines, and growth factors in 81 patients with traumatic SCI at 4 weeks after injury and compared them with those of 26 age-matched healthy control subjects. Patients who developed infections between 4 and 16 weeks after injury exhibited higher numbers of neutrophils and eosinophils, as well as lower numbers of lymphocytes and eotaxin-1 (CCL11) levels. Accordingly, lasso logistic regression showed that incomplete lesions (American Spinal Injury Association Impairment Scale [AIS] C and D grades), the levels of eotaxin-1, and the number of lymphocytes, basophils, and monocytes are predictive of lower odds for infections. On the other hand, the number of neutrophils and eosinophils as well as, in a lesser extent, the levels of IP-10 (CXCL10), MCP-1 (CCL2), BDNF [brain-derived neurotrophic factor], and vascular endothelial growth factor [VEGF]-A, are predictors of increased susceptibility for developing infections. Overall, our results point to systemic immune disbalance after SCI as predictors of infection in a period when infections may greatly interfere with neurological and functional recovery and suggest new pathways and players to further explore novel therapeutic strategies.

Post-COVID Complications after Pressure Ulcer Surgery in Patients with Spinal Cord Injury Associate with Creatine Kinase Upregulation in Adipose Tissue.

The risk of complications following surgical procedures is significantly increased in patients with SARS-CoV-2 infection. However, the mechanisms underlying these correlations are not fully known. Spinal cord injury (SCI) patients who underwent reconstructive surgery for pressure ulcers (PUs) before and during the COVID-19 pandemic were included in this study. The patient's postoperative progression was registered, and the subcutaneous white adipose tissue (s-WAT) surrounding the ulcers was analyzed by proteomic and immunohistochemical assays to identify the molecular/cellular signatures of impaired recovery. Patients with SCI and a COVID-19-positive diagnosis showed worse recovery and severe postoperative complications, requiring reintervention. Several proteins were upregulated in the adipose tissue of these patients. Among them, CKMT2 and CKM stood out, and CKM increased for up to 60 days after the COVID-19 diagnosis. Moreover, CKMT2 and CKM were largely found in MGCs within the s-WAT of COVID patients. Some of these proteins presented post-translational modifications and were targeted by autoantibodies in the serum of COVID patients. Overall, our results indicate that CKMT2, CKM, and the presence of MGCs in the adipose tissue surrounding PUs in post-COVID patients could be predictive biomarkers of postsurgical complications. These results suggest that the inflammatory response in adipose tissue may underlie the defective repair seen after surgery.

Protective Effect of Quercetin 3-O-Glucuronide against Cisplatin Cytotoxicity in Renal Tubular Cells.

Quercetin, a flavonoid with promising therapeutic potential, has been shown to protect from cisplatin nephrotoxicity in rats following intraperitoneal injection, but its low bioavailability curtails its prospective clinical utility in oral therapy. We recently developed a micellar formulation (P-quercetin) with enhanced solubility and bioavailability, and identical nephroprotective properties. As a first aim, we herein evaluated the oral treatment with P-quercetin in rats, which displayed no nephroprotection. In order to unravel this discrepancy, quercetin and its main metabolites were measured by HPLC in the blood and urine after intraperitoneal and oral administrations. Whilst quercetin was absorbed similarly, the profile of its metabolites was different, which led us to hypothesize that nephroprotection might be exerted in vivo by a metabolic derivate. Consequently, we then aimed to evaluate the cytoprotective capacity of quercetin and its main metabolites (quercetin 3-O-glucoside, rutin, tamarixetin, isorhamnetin and quercetin 3-O-glucuronide) against cisplatin toxicity, in HK-2 and NRK-52E tubular cell lines. Cells were incubated for 6 h with quercetin, its metabolites or vehicle (pretreatment), and subsequently 18 h in cotreatment with 10-300 µM cisplatin. Immediately after treatment, cell cultures were subject to the MTT technique as an index of cytotoxicity and photographed under light microscopy for phenotypic assessment. Quercetin afforded no direct cytoprotection and quercetin-3-O-glucuronide was the only metabolite partially preventing the effect of cisplatin in cultured tubule cells. Our results identify a metabolic derivative of quercetin contributing to its nephroprotection and prompt to further explore exogenous quercetin-3-O-glucuronide in the prophylaxis of tubular nephrotoxicity.

CO2-CH4 Exchange Process in Structure I Clathrate Hydrates: Calculations of the Thermodynamic Functions Using a Flexible 2D Lattice-Gas Model and Monte Carlo Simulations.

A two-dimensional lattice-gas model, supplemented by Monte Carlo simulations in the grand canonical ensemble, is applied to study the CO2/CH4 exchange process in sI clathrate hydrates. The coverage dependence of the Helmholtz free energy, chemical potential, entropy, and degree of deformation of the sI structure is given. Two different situations are considered according to the value of the intra- and inter-species' interactions. First, lateral interactions between the guest species and water molecules are introduced by following the well-known Lorentz-Berthelot mixing rules. Second, the study is restricted to an ideal clathrate hydrate, where the lateral interactions are neglected and entropy governs the exchange of CH4 by CO2. In the case of real clathrate hydrates (non-zero lateral interactions), the displacement phenomenon is clearly observed from the behavior of the chemical potential and Helmholtz free energy as functions of coverage. The guest species CO2 has an occupation of more than 80% of the cavities, and therefore displaces the CH4 species. Only 13 to 15% of CH4 remains stagnant in the sI structure. With respect to the degree of deformation, a direct relationship between cell distortion and cell occupancy is observed. Finally, the detailed analysis carried out for the ideal clathrate hydrate allows us to interpret the physical mechanism underlying the exchange process: it is entropy, not energy, that drives the displacement of CH4 by CO2 in sI clathrate hydrates.

Endoscopy-Related Bleeding and Thromboembolic Events in Patients on Direct Oral Anticoagulants or Vitamin K Antagonists.

BACKGROUND & AIMS: Few prospective studies have assessed the safety of direct oral anticoagulants (DOACs) in elective endoscopy. Our primary aim was to compare the risks of endoscopy-related gastrointestinal bleeding and thromboembolic events in patients on DOACs or vitamin K antagonists (VKAs) in this setting. Secondarily, we examined the impact of the timing of anticoagulant resumption on the risk of delayed bleeding in high-risk therapeutic procedures. METHODS: We conducted a multicenter, prospective, observational study from January 2018 to March 2020 of 1602 patients on oral anticoagulants (1004 on VKAs and 598 on DOACs) undergoing 1874 elective endoscopic procedures. Our primary outcomes were 90-day thromboembolic events and 30-day endoscopy-related gastrointestinal bleeding. The inverse probability of treatment weighting propensity score method was used for baseline covariate adjustment. RESULTS: The 2 groups had similar risks of endoscopy-related gastrointestinal bleeding (VKAs vs DOACs, 6.2% vs 6.7%; adjusted odds ratio [OR], 1.05; 95% CI, 0.67-1.65) and thromboembolic events (VKAs vs DOACs, 1.3% vs 1.5%; adjusted OR, 0.90; 95% CI, 0.34-2.38). In high bleeding risk procedures (n = 747), delayed anticoagulant resumption (> 48 hours or 24-48 hours vs < 24 hours) did not reduce the risk of postprocedural bleeding (10.3%, 9%, and 5.8%, respectively; adjusted P = .43). Hot and cold snare polypectomy were the most frequent high-risk interventions (41.8% and 39.8%, respectively). CONCLUSION: In a prospective study of patients on DOACs or VKAs undergoing elective endoscopy, endoscopy-related bleeding and thromboembolic events showed similar risk. Our study suggests that early anticoagulant resumption is safe in most patients, but more data are needed for advanced high-risk therapeutic procedures.

Analysis of aerosol production and aerosol dispersion during otologic surgery.

BACKGROUND: As a respiratory disease, the transmission of Coronavirus disease (COVID-19) is mainly caused by small droplets and aerosols. Healthcare personnel are particularly exposed during otologic surgery given the continuity with the nasopharynx, where the viral load is high, and the use of high-speed instruments. The purpose of the present study is to test a model of droplet dispersion produced in the performance of a drilling procedure on human bone to provide information about its distribution and size of the deposit in similar conditions to those of an operating theatre, to design different preventive measures. MATERIAL AND METHOD: A mastoidectomy and trans-labyrinthine approach were performed on an embalmed human corpse using for irrigation during drilling methylene blue dye in physiological saline solution (pss) at a concentration of 0.324 mg/mL. The distribution of the drops was stablished using semi-absorbent papers of size 52 cm × 42 cm covering the area around the dissection field to a radius of 150 cm and on the corpse at different heights to check vertical dispersion. The collected deposit material was analysed with the microscope at different magnification objectives. RESULTS: Droplets between 2 µm and 2.6 cm were obtained. The visualization of the coloured droplets in the horizontal plane at a magnification of 1.5 was detected at 150 cm from the focus of emission of milling particles. DISCUSSION: According to our study, bone drilling with high speed motors under continuous saline irrigation in a haemorrhagic surgical field increases the amount of aerosols exposing healthcare personnel to additional airbone particles. This risk does not end in the operating rooms as particles smaller than 2 µm can be suspended in the air for hours and could exit the operating theatre due to the use of positive pressure systems. Thus, the use of N95, FFP2, FFP3 or PAPRS should be considered and the development of hood systems to prevent the dispersion of aerosols during these procedures should be considered.

Human embryo polarization requires PLC signaling to mediate trophectoderm specification.

Apico-basal polarization of cells within the embryo is critical for the segregation of distinct lineages during mammalian development. Polarized cells become the trophectoderm (TE), which forms the placenta, and apolar cells become the inner cell mass (ICM), the founding population of the fetus. The cellular and molecular mechanisms leading to polarization of the human embryo and its timing during embryogenesis have remained unknown. Here, we show that human embryo polarization occurs in two steps: it begins with the apical enrichment of F-actin and is followed by the apical accumulation of the PAR complex. This two-step polarization process leads to the formation of an apical domain at the 8-16 cell stage. Using RNA interference, we show that apical domain formation requires Phospholipase C (PLC) signaling, specifically the enzymes PLCB1 and PLCE1, from the eight-cell stage onwards. Finally, we show that although expression of the critical TE differentiation marker GATA3 can be initiated independently of embryo polarization, downregulation of PLCB1 and PLCE1 decreases GATA3 expression through a reduction in the number of polarized cells. Therefore, apical domain formation reinforces a TE fate. The results we present here demonstrate how polarization is triggered to regulate the first lineage segregation in human embryos.