Histological 3D reconstruction and in vivo lineage tracing of the human endometrium.

Regular menstrual shedding and repair of the endometrial functionalis is unique to humans and higher-order primates. The current consensus postulates endometrial glands to have a single-tubular architecture, where multi-potential stem cells reside in the blind-ending glandular-bases. Utilising fixed samples from patients, we have studied the three-dimensional (3D) micro-architecture of the human endometrium. We demonstrate that some non-branching, single, vertical functionalis glands originate from a complex horizontally interconnecting network of basalis glands. The existence of a multipotent endometrial epithelial stem cell capable of regenerating the entire complement of glandular lineages was demonstrated by in vivo lineage tracing, using naturally occurring somatic mitochondrial DNA mutations as clonal markers. Vertical tracking of mutated clones showed that at least one stem-cell population resides in the basalis glands. These novel findings provide insight into the efficient and scar-less regenerative potential of the human endometrium. © 2020 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

Anterior Gradient Protein 3 and S100 Calcium-Binding Protein P Levels in Different Endometrial Epithelial Compartments May Play an Important Role in Recurrent Pregnancy Failure.

Recurrent implantation failure (RIF) and recurrent pregnancy loss (RPL) are distressing conditions without effective treatments. The luminal epithelium (LE) is integral in determining receptivity of the endometrium, whereas functionalis glands and stroma aid in nurturing early embryo development. Calcium signalling pathways are known to be of vital importance to embryo implantation and pregnancy establishment, and anterior gradient protein 3 (AGR3) and S100 calcium-binding protein P (S100P) are involved with these pathways. We initially examined 20 full-thickness endometrial biopsies from premenopausal women across the menstrual cycle to characterize levels of AGR3 protein in each endometrial sub-region at the cellular level. A further 53 endometrial pipelle biopsies collected in the window of implantation were subsequently assessed to determine differential endometrial AGR3 and S100P levels relevant to RIF (n = 13) and RPL (n = 10) in comparison with parous women (n = 30) using immunohistochemistry. Significantly higher AGR3 and S100P immunostaining was observed in ciliated cells of the LE of women with recurrent reproductive failure compared with parous women, suggesting aberrant subcellular location-associated pathophysiology for these conditions. The nuclear localisation of S100P may allow transcriptional regulatory function, which is necessary for implantation of a viable pregnancy. Further work is thus warranted to assess their utility as diagnostic/therapeutic targets.

Fucoidan Inhibition of Osteosarcoma Cells Is Species and Molecular Weight Dependent.

Fucoidan is a brown algae-derived polysaccharide having several biomedical applications. This study simultaneously compares the anti-cancer activities of crude fucoidans from Fucus vesiculosus and Sargassum filipendula, and effects of low (LMW, 10-50 kDa), medium (MMW, 50-100 kDa) and high (HMW, >100 kDa) molecular weight fractions of S. filipendula fucoidan against osteosarcoma cells. Glucose, fucose and acid levels were lower and sulphation was higher in F. vesiculosus crude fucoidan compared to S. filipendula crude fucoidan. MMW had the highest levels of sugars, acids and sulphation among molecular weight fractions. There was a dose-dependent drop in focal adhesion formation and proliferation of cells for all fucoidan-types, but F. vesiculosus fucoidan and HMW had the strongest effects. G1-phase arrest was induced by F. vesiculosus fucoidan, MMW and HMW, however F. vesiculosus fucoidan treatment also caused accumulation in the sub-G1-phase. Mitochondrial damage occurred for all fucoidan-types, however F. vesiculosus fucoidan led to mitochondrial fragmentation. Annexin V/PI, TUNEL and cytochrome c staining confirmed stress-induced apoptosis-like cell death for F. vesiculosus fucoidan and features of stress-induced necrosis-like cell death for S. filipendula fucoidans. There was also variation in penetrability of different fucoidans inside the cell. These differences in anti-cancer activity of fucoidans are applicable for osteosarcoma treatment.

The ZT Biopolymer: A Self-Assembling Protein Scaffold for Stem Cell Applications.

The development of cell culture systems for the naturalistic propagation, self-renewal and differentiation of cells ex vivo is a high goal of molecular engineering. Despite significant success in recent years, the high cost of up-scaling cultures, the need for xeno-free culture conditions, and the degree of mimicry of the natural extracellular matrix attainable in vitro using designer substrates continue to pose obstacles to the translation of cell-based technologies. In this regard, the ZT biopolymer is a protein-based, stable, scalable, and economical cell substrate of high promise. ZT is based on the naturally occurring assembly of two human proteins: titin-Z1Z2 and telethonin. These protein building blocks are robust scaffolds that can be conveniently functionalized with full-length proteins and bioactive peptidic motifs by genetic manipulation, prior to self-assembly. The polymer is, thereby, fully encodable. Functionalized versions of the ZT polymer have been shown to successfully sustain the long-term culturing of human embryonic stem cells (hESCs), human induced pluripotent stem cells (hiPSCs), and murine mesenchymal stromal cells (mMSCs). Pluripotency of hESCs and hiPSCs was retained for the longest period assayed (4 months). Results point to the large potential of the ZT system for the creation of a modular, pluri-functional biomaterial for cell-based applications.

Control of the Porous Structure of Polystyrene Particles Obtained by Nonsolvent Induced Phase Separation.

Porous polystyrene microspheres were produced by a process of nonsolvent induced phase separation (NIPS) from ternary polymer-solvent-nonsolvent (polystyrene-toluene-ethanol) systems and characterized by scanning electron microscopy (SEM) and small-angle X-ray scattering (SAXS) techniques. This study provides evidence for a link between the structural morphology of the porous polystyrene particles and the polystyrene concentration in the initial solutions. A reciprocal relationship between pore diameter and polymer concentration was observed for the systems with the polymer amount below the critical chain overlap concentration, C*. Above C*, this relationship breaks down. The reciprocal relationship between porosity and polymer concentration can be used to facilitate the fine control of the void size. We demonstrate that the observed reciprocal relationship between pore diameter and polymer concentration correlates well with the relative amount of nonsolvent present in the system at the onset of the phase separation process. The pore size can be reduced and, consequently, the pore surface area can be increased either by reducing the polymer concentration in the initial solution or by decreasing the polymer molecular weight in the sample composition.

High-volume haemofiltration for sepsis in adults.

BACKGROUND: Severe sepsis and septic shock are leading causes of death in the intensive care unit (ICU), despite advances in the treatment of patients with severe sepsis and septic shock, including early recognition, appropriate treatment with antibiotics and support of organs that may have been affected by the illness. High-volume haemofiltration (HVHF) is a blood purification technique that may improve outcomes in severe sepsis or septic shock. The technique of HVHF has evolved from renal replacement therapies used in the ICU to treat critically ill patients with acute kidney injury (AKI). This review was first published in 2013 and was updated in 2016. OBJECTIVES: To investigate whether HVHF improves outcomes in critically ill adults admitted to the intensive care unit with severe sepsis or septic shock. The primary outcome of this systematic review is patient mortality; secondary outcomes include duration of stay, severity of organ dysfunction and adverse events. SEARCH METHODS: For this updated version, we extended searches of the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, Latin American Caribbean Health Sciences Literature (LILACS), Web of Science and the Cumulative Index to Nursing and Allied Health Literature (CINAHL) to 31 December 2015. The original search was performed in 2011. We also searched trials registers. SELECTION CRITERIA: We included randomized controlled trials (RCTs) and quasi-randomized trials comparing HVHF or high-volume haemodiafiltration versus standard or usual dialysis therapy, as well as RCTs and quasi-randomized trials comparing HVHF or high-volume haemodiafiltration versus no similar dialysis therapy. These studies involved adults treated in critical care units. DATA COLLECTION AND ANALYSIS: Three review authors independently extracted data and assessed trial quality. We sought additional information from trialists as required. MAIN RESULTS: We included four randomized trials involving 200 participants. Owing to small numbers of studies and participants, it was not possible to combine data for all outcomes. Two trials reported 28-day mortality, and one trial reported hospital mortality; in the third trial, the number of deaths stated did not match the quoted mortality rates. The pooled risk ratio (95% confidence interval) for 28-day mortality associated with HVHF was 0.89 (0.60 to 1.32, two trials, 146 participants, low-quality evidence). One study (137 participants, low-quality evidence) reported length of stay in the ICU. Two trials (170 participants, low-quality evidence) reported organ dysfunction, but we could not pool results owing to reporting differences. Three studies (189 participants, low-quality evidence) reported on haemodynamic changes, but we could not pool results owing to reporting differences. Investigators reported no adverse events. Overall, the included studies had low risk of bias. AUTHORS' CONCLUSIONS: Investigators reported no adverse effects of HVHF (low-quality evidence). The results of this meta-analysis show that very few studies have been conducted to investigate the use of HVHF in critically ill patients with severe sepsis or septic shock (four studies, 201 participants, low-quality evidence). Researchers should consider additional randomized controlled trials that are large and multi-centred and have clinically relevant outcome measures. The cost-effectiveness of HVHF should also be studied. .

Recipient obesity and outcomes after kidney transplantation: a systematic review and meta-analysis.

BACKGROUND: The prevalence of obesity is increasing globally and is associated with chronic kidney disease and premature mortality. However, the impact of recipient obesity on kidney transplant outcomes remains unclear. This study aimed to investigate the association between recipient obesity and mortality, death-censored graft loss and delayed graft function (DGF) following kidney transplantation. METHODS: A systematic review and meta-analysis was conducted using Medline, Embase and the Cochrane Library. Observational studies or randomized controlled trials investigating the association between recipient obesity at transplantation and mortality, death-censored graft loss and DGF were included. Obesity was defined as a body mass index (BMI) of ≥30 kg/m(2). Obese recipients were compared with those with a normal BMI (18.5-24.9 kg/m(2)). Pooled estimates of hazard ratios (HRs) for patient mortality or death-censored graft loss and odds ratios (ORs) for DGF were calculated. RESULTS: Seventeen studies including 138 081 patients were analysed. After adjustment, there was no significant difference in mortality risk in obese recipients [HR = 1.24, 95% confidence interval (CI) = 0.90-1.70, studies = 5, n = 83 416]. However, obesity was associated with an increased risk of death-censored graft loss (HR = 1.06, 95% CI = 1.01-1.12, studies = 5, n = 83 416) and an increased likelihood of DGF (OR = 1.68, 95% CI = 1.39-2.03, studies = 4, n = 28 847). CONCLUSIONS: Despite having a much higher likelihood of DGF, obese transplant recipients have only a slightly increased risk of graft loss and experience similar survival to recipients with normal BMI.

Glycated hemoglobin and risk of death in diabetic patients treated with hemodialysis: a meta-analysis.

BACKGROUND: Studies investigating the association between glycated hemoglobin (HbA1c) level and mortality risk in diabetic patients receiving hemodialysis have shown conflicting results. STUDY DESIGN: We conducted a systematic review and meta-analysis using MEDLINE, EMBASE, Web of Science, and the Cochrane Library. SETTING & POPULATION: Diabetic patients on maintenance hemodialysis therapy. SELECTION CRITERIA FOR STUDIES: Observational studies or randomized controlled trials investigating the association between HbA1c values and mortality risk. Study authors were asked to provide anonymized individual patient data or reanalyze results according to a standard template. PREDICTOR: Single measurement or mean HbA1c values. Mean HbA1c values were calculated using all individual-patient HbA1c values during the follow-up period of contributing studies. OUTCOME: HR for mortality risk. RESULTS: 10 studies (83,684 participants) were included: 9 observational studies and one secondary analysis of a randomized trial. After adjustment for confounders, patients with baseline HbA1c levels ≥ 8.5% (≥ 69 mmol/mol) had increased mortality (7 studies; HR, 1.14; 95% CI, 1.09-1.19) compared with patients with HbA1c levels of 6.5%-7.4% (48-57mmol/mol). Likewise, patients with a mean HbA1c value ≥ 8.5% also had a higher adjusted risk of mortality (6 studies; HR,1.29; 95% CI, 1.23-1.35). There was a small but nonsignificant increase in mortality associated with mean HbA1c levels ≤ 5.4% (≤ 36 mmol/mol; 6 studies; HR, 1.09; 95% CI, 0.89-1.34). Sensitivity analyses in incident (≤ 90 days of hemodialysis) and prevalent patients (>90 days of hemodialysis) showed a similar pattern. In incident patients, mean HbA1c levels ≤ 5.4% also were associated with increased mortality risk (4 studies; HR, 1.29; 95% CI, 1.23-1.35). LIMITATIONS: Observational study data and inability to adjust for diabetes type in all studies. CONCLUSIONS: Despite concerns about the utility of HbA1c measurement in hemodialysis patients, high levels (≥ 8.5%) are associated with increased mortality risk. Very low HbA1c levels (≤ 5.4%) also may be associated with increased mortality risk.

Diagnostic utility of clinicodemographic, biochemical and metabolite variables to identify viable pregnancies in a symptomatic cohort during early gestation.

A significant number of pregnancies are lost in the first trimester and 1-2% are ectopic pregnancies (EPs). Early pregnancy loss in general can cause significant morbidity with bleeding or infection, while EPs are the leading cause of maternal mortality in the first trimester. Symptoms of pregnancy loss and EP are very similar (including pain and bleeding); however, these symptoms are also common in live normally sited pregnancies (LNSP). To date, no biomarkers have been identified to differentiate LNSP from pregnancies that will not progress beyond early gestation (non-viable or EPs), defined together as combined adverse outcomes (CAO). In this study, we present a novel machine learning pipeline to create prediction models that identify a composite biomarker to differentiate LNSP from CAO in symptomatic women. This prospective cohort study included 370 participants. A single blood sample was prospectively collected from participants on first emergency presentation prior to final clinical diagnosis of pregnancy outcome: LNSP, miscarriage, pregnancy of unknown location (PUL) or tubal EP (tEP). Miscarriage, PUL and tEP were grouped together into a CAO group. Human chorionic gonadotrophin ß (ß-hCG) and progesterone concentrations were measured in plasma. Serum samples were subjected to untargeted metabolomic profiling. The cohort was randomly split into train and validation data sets, with the train data set subjected to variable selection. Nine metabolite signals were identified as key discriminators of LNSP versus CAO. Random forest models were constructed using stable metabolite signals alone, or in combination with plasma hormone concentrations and demographic data. When comparing LNSP with CAO, a model with stable metabolite signals only demonstrated a modest predictive accuracy (0.68), which was comparable to a model of ß-hCG and progesterone (0.71). The best model for LNSP prediction comprised stable metabolite signals and hormone concentrations (accuracy = 0.79). In conclusion, serum metabolite levels and biochemical markers from a single blood sample possess modest predictive utility in differentiating LNSP from CAO pregnancies upon first presentation, which is improved by variable selection and combination using machine learning. A diagnostic test to confirm LNSP and thus exclude pregnancies affecting maternal morbidity and potentially life-threatening outcomes would be invaluable in emergency situations.

High-volume haemofiltration for sepsis.

BACKGROUND: Severe sepsis and septic shock are leading causes of death in the intensive care unit (ICU). This is despite advances in the management of patients with severe sepsis and septic shock including early recognition, source control, timely and appropriate administration of antimicrobial agents, and goal directed haemodynamic, ventilatory and metabolic therapies. High-volume haemofiltration (HVHF) is a blood purification technique which may improve outcomes in critically ill patients with severe sepsis or septic shock. The technique of HVHF has evolved from renal replacement therapies used to treat acute kidney injury (AKI) in critically ill patients in the ICU. OBJECTIVES: This review assessed whether HVHF improves clinical outcome in adult critically ill patients with sepsis in an ICU setting. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, 2011, Issue 7); MEDLINE (1990 to August 2011), EMBASE (1990 to August 2011); LILACS (1982 to August 2011), Web of Science (1990 to August 2011), CINAHL (1982 to August 2011) and specific websites. SELECTION CRITERIA: We included randomized controlled trials (RCTs) and quasi-randomized trials comparing HVHF or high-volume haemodiafiltration to standard or usual dialysis therapy; and RCTs and quasi-randomized trials comparing HVHF or high-volume haemodiafiltration to no similar dialysis therapy. The studies involved adults in critical care units. DATA COLLECTION AND ANALYSIS: Three review authors independently extracted data and assessed trial quality. We sought additional information as required from trialists. MAIN RESULTS: We included three randomized trials involving 64 participants. Due to the small number of studies and participants, it was not possible to combine data or perform sub-group analyses. One trial reported ICU and 28-day mortality, one trial reported hospital mortality and in the third, the number of deaths stated did not match the quoted mortality rates. No trials reported length of stay in ICU or hospital and one reported organ dysfunction. No adverse events were reported. Overall, the included studies had a low risk of bias. AUTHORS' CONCLUSIONS: There were no adverse effects of HVHF reported.There is insufficient evidence to recommend the use of HVHF in critically ill patients with severe sepsis and or septic shock except as interventions being investigated in the setting of a randomized clinical trial. These trials should be large, multi-centred and have clinically relevant outcome measures. Financial implications should also be assessed.

The role of iron in the pathogenesis of endometriosis: a systematic review.

STUDY QUESTION: What is the role of iron in the pathophysiology of endometriosis? SUMMARY ANSWER: Iron excess is demonstrated wherever endometriotic tissues are found and is associated with oxidative stress, an inflammatory micro-environment, and cell damage; the iron-mediated oxidative stress is independently linked to subfertility, symptom severity, and malignant transformation. WHAT IS KNOWN ALREADY: Iron is found in excess in endometriotic tissues, and multiple mechanisms have been studied and posited to explain this. It is clear that iron excess plays a vital role in promoting oxidative stress and cell damage. The evidence base is large, but no comprehensive reviews exist to summarize our understanding and highlight the overarching themes to further our understanding and suggest future directions of study for the field. STUDY DESIGN SIZE DURATION: This systematic review with a thematic analysis retrieved studies from the PubMed, Embase, Web of Science, and Cochrane Library databases and searches were conducted from inception through to August 2022. Human and animal studies published in the English language were included and identified using a combination of exploded MeSH terms ('Iron' and 'Endometriosis') and free-text search terms ('Iron', 'Ferric', 'Ferrous', 'Endometriosis', 'Endometrioma'). PARTICIPANTS/MATERIALS SETTING METHODS: This review was reported in accordance with the PRISMA guidelines. All studies reporting original data concerning the role of iron or iron complexes in the pathophysiology of endometriosis were included. Studies that did not report original data or provided a review of the field were excluded. Bias analysis was completed for each included study by using the Newcastle-Ottawa scoring system. MAIN RESULTS AND THE ROLE OF CHANCE: There were 776 records identified and these were screened down to 53 studies which met the eligibility criteria, including 6 animal and 47 human studies, with 3556 individual participants. Iron excess is demonstrated in various tissues and fluids, including ovarian endometriomas, ovarian follicles, ectopic endometriotic lesions, and peritoneal fluid. Markers of oxidative stress are strongly associated with high iron levels, and aberrant expression of iron-transport proteins has been demonstrated. Abnormal resistance to ferroptosis is likely. Iron-mediated oxidative stress is responsible for a pro-inflammatory micro-environment and is linked to subfertility, symptom severity, and, possibly, malignant transformation. LIMITATIONS REASONS FOR CAUTION: A minority of the included studies were of objectively low quality with a high risk of bias and may lead to misleading conclusions. Additionally, multiple studies failed to appropriately characterize the included patients by known confounding variables, such as menstrual cycle phase, which may introduce bias to the findings. WIDER IMPLICATIONS OF THE FINDINGS: Current literature depicts a central role of aberrant iron mechanics and subsequent oxidative stress in endometriosis. It is likely that iron excess is at least partly responsible for the persistence and proliferation of ectopic endometriotic lesions. As such, iron mechanics represent an attractive target for novel therapeutics, including iron chelators or effectors of the iron-oxidative stress pathway. There are significant gaps in our current understanding, and this review highlights and recommends several topics for further research. These include the role of iron chelation, resistance to ferroptosis, the relationship between iron excess and localized hypoxia, systemic iron pathophysiology in endometriosis, and the role of oxidative stress in malignant transformation. STUDY FUNDING/COMPETING INTERESTS: J.W. and S.G.P. are supported by clinical fellowships at Liverpool University Hospital NHS Foundation trust. No additional funding was requested or required for the completion of this work. C.J.H. is supported by a Wellbeing of Women project grant (RG2137). D.K.H. is supported by a Wellbeing of Women project grant (RG2137) and an MRC clinical research training fellowship (MR/V007238/1). The authors have no conflicts of interest to declare. REGISTRATION NUMBER: A protocol was prospectively registered with the PROSPERO database in August 2021 (CRD42021272818).

Postoperative Opioid Pain Medication Usage Following Adult Tonsillectomy.

INTRODUCTION: The purpose of this study was to determine if short-term, high-quantity opioid use following adult tonsillectomy in active duty military members results in opioid misuse, using a proxy measure of referrals to substance abuse rehabilitation programs. MATERIALS AND METHODS: An Institutional Review Board-approved retrospective chart review was performed of 741 active duty patients who underwent tonsillectomy between 2012 and 2017. Data collection included preoperative medications within 60 days of surgery, all postoperative opioid prescriptions up to 12 months following surgery, and referrals to substance abuse rehabilitation within a year of surgery. RESULTS: Out of 741 patients, 658 met inclusion criteria. Fifty-one percent were women and the average age was 26 years. Fifty-nine percent of patients received 5 mg/325 mg oxycodone/acetaminophen as their initial postoperative pain medication. The average number of opioid tablets prescribed was 70 ± 18. Ninety three percent of patients received at least 60 tabs. The refill rate within 30 days of tonsillectomy was 38.6%. In the year following surgery, 25.4% of patients received additional doses of outpatient opioids for other indications. Nineteen patients (2.9%) were referred for substance abuse treatment within 1 year of tonsillectomy: seventeen for alcohol abuse, one for marijuana, and one for alcohol/marijuana. There were no referrals for opiate misuse or abuse. CONCLUSION: Short-term, high-quantity opioid treatment of post-tonsillectomy pain in active duty adults does not result in long-term opioid misuse, as measured by substance abuse treatment program referrals within a year after surgery. This finding supports the appropriateness of adequate short-term narcotic medication treatment. The long-term readiness of these patients appears unaffected by long-term opioid misuse or abuse. Even with this finding, there is an institutional shift to multi-modality pain management and appropriate opioid reduction to further mitigate the risk of opioid misuse. Extrapolation of these findings to all adult tonsillectomy patients should be done with caution, as there are several protective factors in the active duty population such as stable full-time employment with mandatory random drug screening.

Investigation of Adult Post-Tonsillectomy Hemorrhage Rates and the Impact of NSAID Use.

OBJECTIVES/HYPOTHESIS: Tonsillectomy is one of the most common ambulatory surgeries performed in the United States, yet the incidence of post-tonsillectomy hemorrhage (PTH) in adults remains unclear. In addition, any association between non-steroidal anti-inflammatory drugs (NSAIDs) and PTH in adults is currently unknown. The aim of this study is to examine the incidence and management of adult PTH at a single academic center and to assess for any association between NSAID use and PTH in adults. STUDY DESIGN: Retrospective chart review. METHODS: We conducted a retrospective chart review of adult tonsillectomies performed at our institution between January 1, 2012, and December 30, 2019. Demographics, past medical history, medications, NSAID use, surgical indication, bleeding events, and interventions were documented. The rate of PTH was calculated, logistic regression was performed to assess for any predictive factors, and odds ratios were calculated for NSAID use and PTH. RESULTS: A total of 1,057 adult tonsillectomies were performed within the aforementioned time period. A total of 126 patients experienced 163 bleeding events for a postoperative hemorrhage rate of 11.9%. Most were controlled with bedside interventions, while 29 (23%) bled more than once. The hemorrhage rate for those who were not prescribed NSAIDs postoperatively (n = 625) was 11.7%, compared to 12.6% for those who did receive NSAIDs postoperatively (n = 432), which was not significantly different (adjusted odds ratio 1.01, 95% confidence interval 0.69-1.49; P = .95). CONCLUSIONS: This retrospective cohort study of 1,057 adult patients found the incidence of PTH to be 11.9%. This study found no association between the use of NSAIDs and the rate of PTH, although a higher-powered study is needed. LEVEL OF EVIDENCE: 3 Laryngoscope, 132:949-953, 2022.

The Role of Endometrial Stem/Progenitor Cells in Recurrent Reproductive Failure.

Recurrent implantation failure (RIF) and recurrent pregnancy loss (RPL), collectively referred to as recurrent reproductive failure (RRF), are both challenging conditions with many unanswered questions relating to causes and management options. Both conditions are proposed to be related to an aberrant endometrial microenvironment, with different proposed aetiologies related to a restrictive or permissive endometrium for an invading embryo. The impressive regenerative capacity of the human endometrium has been well-established and has led to the isolation and characterisation of several subtypes of endometrial stem/progenitor cells (eSPCs). eSPCs are known to be involved in the pathogenesis of endometrium-related disorders (such as endometriosis) and have been proposed to be implicated in the pathogenesis of RRF. This review appraises the current knowledge of eSPCs, and their involvement in RRF, highlighting the considerable unknown aspects in this field, and providing avenues for future research to facilitate much-needed advances in the diagnosis and management of millions of women suffering with RRF.

The immune cell profile of human fallopian tubes in health and benign pathology: a systematic review.

The fallopian tubes (FT) play a key role in fertility by facilitating the movement of gametes to promote fertilisation and, subsequently, passage of the zygote for implantation. Histologically, the FT mucosa consists of three main cell types: secretory, ciliated and peg cells. In addition, several studies have reported the presence of immune cells. This systematic review aims to present a comprehensive analysis of the immune cell populations in the human FT, both in health and benign pathology, to promote a better understanding of tubal pathologies and their influence on infertility. A comprehensive literature search was conducted across five databases and augmented with manual citation chaining. Forty-two eligible studies were selected in accordance with PRISMA guidelines. Following screening, risk of bias assessments were conducted, data extracted and the findings presented thematically. T lymphocytes, predominantly CD8+ T cells, represent the most abundant immune cell population within the healthy FT, with B lymphocytes, macrophages, NK cells and dendritic cells also localised to the tubal mucosa. There is evidence to suggest that lymphocyte and macrophage populations are susceptible to changes in the concentration of reproductive hormones. Tubal ectopic pregnancy, salpingitis, hydrosalpinx and endometriosis are all characterised by an increased population of macrophages in comparison to healthy FT. However, given the inconsistent evidence presented between studies, and the lack of studies examining all immune cell subtypes in tubal pathologies, only limited conclusions can be formulated on pathology-specific immune cell populations, and further research is required for validation.

Burn Pit Exposure Is Associated With Increased Sinonasal Disease.

OBJECTIVE: The aim of this study was to determine whether self-reported burn pit exposure is associated with increased subjective and objective sinus disease. DESIGN: A cross-sectional study was performed evaluating consecutive adult patients presenting to a US Military rhinology clinic. Demographics, medical histories, sinonasal quality-of-life scores, and nasal endoscopy examinations were obtained. Participants were divided into three cohorts based on self-reported exposure histories and outcomes compared. RESULTS: One hundred eighty-six patients met the inclusion criteria, the majority of whom were male. Patients with burn pit exposure had worse Sinonasal Outcome Test-22 scores (49.9) compared with those deployed without burn pit exposure (31.8) or never deployed (31.5). Endoscopic findings demonstrated worse disease within those exposed (Lund-Kennedy score, 3.3) compared with the other cohorts (1.8 and 1.7, respectively). CONCLUSIONS: These novel findings suggest that deployment-related burn pit exposure is associated with increased subjective and objective sinus disease.

Altered endometrial oestrogen-responsiveness and recurrent reproductive failure.

Abstract: Recurrent reproductive failure (RRF) encompasses recurrent implantation failure (RIF) and recurrent pregnancy loss (RPL). These highly prevalent, distressing conditions have many unanswered questions regarding aetiology and management. Oestrogen receptor beta (ERß) is the predominant oestrogen receptor expressed in the vascular endothelium of the endometrium during the window of implantation (WOI). The establishment of normal endometrial receptivity is integrally associated with progesterone receptor (PR). Therefore, we aimed to investigate whether women with RRF have clinical, type-specific endometrial aberrations of ERß, PR and Ki-67 expression during the WOI. Thirty-eight endometrial biopsies were collected; 29 RRF (10 RIF, 9 recurrent loss of early pregnancy (RLEP) and 10 recurrent fetal loss (RFL)) and 9 fertile controls (FC). Within RIF, RLEP and RFL groups, the perivascular compartment showed significantly lower levels of ERß vs FC (P = 0.02, P = 0.03 and P = 0.01, respectively). Vascular endothelium also displayed significantly lower levels of ERß within RIF and RFL cohorts vs FC (P = 0.03 and P = 0.003). The expression of Ki-67 was significantly lower within vascular endothelium of all RRF; RIF (P = 0.02), RLEP (P = 0.02) and RFL (P <0.01). PR was significantly reduced (P <0.001) in the perivascular area of women with RIF. These findings provide novel insights into biological correlates of clinical subtypes of RRF. The endometrium of women with RRF display significantly altered levels of ERß, PR and Ki-67 during the WOI, furthering our understanding of the defective endometrial phenotype of women suffering from RRF, with possible impaired glandular function, angiogenesis and decidualisation. Lay summary: Recurrent reproductive failure (RRF) refers to a group of devastating conditions with many unanswered questions regarding their causes and treatment options. The lining of the womb, the endometrium, is primed and suitable for successful embryo implantation for a short time during the menstrual cycle; the window of implantation (WOI). Oestrogen is a key hormone that plays an important role in regulating the endometrium and its effects are exerted via two oestrogen receptor subtypes. Oestrogen receptor beta (ERß) is the main oestrogen receptor present during the WOI. Progesterone receptor allows the other main hormone, progesterone, to influence the endometrial activity and Ki-67 reflects the proliferative activity of the cells within the endometrium. We investigated the expression of these markers in endometrial samples collected from women with RRF and proven fertility. We found that the endometrium of women with RRF has significantly lower levels of ERß and Ki-67 during the WOI, possibly leading to unsuccessful pregnancies.

Novel microarchitecture of human endometrial glands: implications in endometrial regeneration and pathologies.

BACKGROUND: Human endometrium remains a poorly understood tissue of the female reproductive tract. The superficial endometrial functionalis, the site of embryo implantation, is repeatedly shed with menstruation, and the stem cell-rich deeper basalis is postulated to be responsible for the regeneration of the functionalis. Two recent manuscripts have demonstrated the 3D architecture of endometrial glands. These manuscripts have challenged and replaced the prevailing concept that these glands end in blind pouches in the basalis layer that contain stem cells in crypts, as in the intestinal mucosa, providing a new paradigm for endometrial glandular anatomy. This necessitates re-evaluation of the available evidence on human endometrial regeneration in both health and disease in the context of this previously unknown endometrial glandular arrangement. OBJECTIVE AND RATIONALE: The aim of this review is to determine if the recently discovered glandular arrangement provides plausible explanations for previously unanswered questions related to human endometrial biology. Specifically, it will focus on re-appraising the theories related to endometrial regeneration, location of stem/progenitor cells and endometrial pathologies in the context of this recently unravelled endometrial glandular organization. SEARCH METHODS: An extensive literature search was conducted from inception to April 2021 using multiple databases, including PubMed/Web of Science/EMBASE/Scopus, to select studies using keywords applied to endometrial glandular anatomy and regeneration, and the references included in selected publications were also screened. All relevant publications were included. OUTCOMES: The human endometrial glands have a unique and complex architecture; branched basalis glands proceed in a horizontal course adjacent to the myometrium, as opposed to the non-branching, vertically coiled functionalis glands, which run parallel to each other as is observed in intestinal crypts. This complex network of mycelium-like, interconnected basalis glands is demonstrated to contain endometrial epithelial stem cells giving rise to single, non-branching functionalis glands. Several previous studies that have tried to confirm the existence of epithelial stem cells have used methodologies that prevent sampling of the stem cell-rich basalis. More recent findings have provided insight into the efficient regeneration of the human endometrium, which is preferentially evolved in humans and menstruating upper-order primates. WIDER IMPLICATIONS: The unique physiological organization of the human endometrial glandular element, its relevance to stem cell activity and scarless endometrial regeneration will inform reproductive biologists and clinicians to direct their future research to determine disease-specific alterations in glandular anatomy in a variety of endometrial pathological conditions.

COVID-19 Preprocedural Testing: What About the False Positives?

In the COVID-19 era, preprocedural patients are almost uniformly screened for symptoms, asked to quarantine preoperatively, and then undergo a test of uncertain validity with very low pretest probability. A small percentage of these tests return positive. As a result, surgical procedures are delayed and patients are required to quarantine. Are these asymptomatic patients truly positive for COVID-19? What are the impacts of these test results on the patient and the health care system? In the following commentary, we review how the uncertain validity of reverse transcription polymerase chain reaction testing combined with a low-prevalence population predisposes for false-positive results. As a mitigation strategy, we ask that readers refocus on the fundamental principal of diagnostic testing: pretest probability.

Olfactory Rod Cells: A Rare Cell Type in the Larval Zebrafish Olfactory Epithelium With a Large Actin-Rich Apical Projection.

We report the presence of a rare cell type, the olfactory rod cell, in the developing zebrafish olfactory epithelium. These cells each bear a single actin-rich rod-like apical projection extending 5-10 µm from the epithelial surface. Live imaging with a ubiquitous Lifeact-RFP label indicates that the olfactory rods can oscillate. Olfactory rods arise within a few hours of the olfactory pit opening, increase in numbers and size during larval stages, and can develop in the absence of olfactory cilia. Olfactory rod cells differ in morphology from the known classes of olfactory sensory neuron, but express reporters driven by neuronal promoters. A sub-population of olfactory rod cells expresses a Lifeact-mRFPruby transgene driven by the sox10 promoter. Mosaic expression of this transgene reveals that olfactory rod cells have rounded cell bodies located apically in the olfactory epithelium and have no detectable axon. We offer speculation on the possible function of these cells in the Discussion.