Classification of Free-Living Body Posture with ECG Patch Accelerometers: Application to the Multicenter AIDS Cohort Study.

Purpose: As health studies increasingly monitor free-living heart performance via ECG patches with accelerometers, researchers will seek to investigate cardio-electrical responses to physical activity and sedentary behavior, increasing demand for fast, scalable methods to process accelerometer data. We extend a posture classification algorithm for accelerometers in ECG patches when researchers do not have ground-truth labels or other reference measurements (i.e., upright measurement). Methods: Men living with and without HIV in the Multicenter AIDS Cohort study wore the Zio XT® for up to two weeks (n = 1,250). Our novel extensions for posture classification include (1) estimation of an upright posture for each individual without a reference upright measurement; (2) correction of the upright estimate for device removal and re-positioning using novel spherical change-point detection; and (3) classification of upright and recumbent periods using a clustering and voting process rather than a simple inclination threshold used in other algorithms. As no posture labels exist in the free-living environment, we perform numerous sensitivity analyses and evaluate the algorithm against labelled data from the Towson Accelerometer Study, where participants wore accelerometers at the waist. Results: On average, 87.1% of participants were recumbent at 4am and 15.5% were recumbent at 1pm. Participants were recumbent 54 minutes longer on weekends compared to weekdays. Performance was good in comparison to labelled data in a separate, controlled setting (accuracy = 96.0%, sensitivity = 97.5%, specificity = 95.9%). Conclusions: Posture may be classified in the free-living environment from accelerometers in ECG patches even without measuring a standard upright position. Furthermore, algorithms that fail to account for individuals who rotate and re-attach the accelerometer may fail in the free-living environment.

A joint frailty model for recurrent and competing terminal events: Application to delirium in the ICU.

Joint models linking longitudinal biomarkers or recurrent event processes with a terminal event, for example, mortality, have been studied extensively. Motivated by studies of recurrent delirium events in patients receiving care in an intensive care unit (ICU), we devise a joint model for a recurrent event process and multiple terminal events. Being discharged alive from the ICU or experiencing mortality may be associated with a patient's hazard of delirium, violating the assumption of independent censoring. Moreover, the direction of the association between the hazards of delirium and mortality may be opposite of the direction of association between the hazards of delirium and ICU discharge. Hence treating either terminal event as independent censoring may bias inferences. We propose a competing joint model that uses a latent frailty to link a patient's recurrent and competing terminal event processes. We fit our model to data from a completed placebo-controlled clinical trial, which studied whether Haloperidol could prevent death and delirium among ICU patients. The clinical trial served as a foundation for a simulation study, in which we evaluate the properties, for example, bias and confidence interval coverage, of the competing joint model. As part of the simulation study, we demonstrate the shortcomings of using a joint model with a recurrent delirium process and a single terminal event to study delirium in the ICU. Lastly, we discuss limitations and possible extensions for the competing joint model. The competing joint model has been added to frailtypack, an R package for fitting an assortment of joint models.

The impact of tirzepatide and glucagon-like peptide 1 receptor agonists on oral hormonal contraception.

BACKGROUND: Tirzepatide is a dual glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) receptor agonist (RA) whose mechanism of action leads to a greater effect of gastric emptying (GE) than typical GLP-1 RAs. After the first dose of tirzepatide, GE is most substantially delayed. The drug then undergoes tachyphylaxis after subsequent doses. Although data on GLP1-RAs have historically demonstrated a lack of impact on bioavailability of oral hormonal contraceptives, manufacturer recommendations for tirzepatide indicate an interaction exists. OBJECTIVES: The objectives of this literature review were to review trial data on differences in the impact of tirzepatide and GLP-1 RAs on oral hormonal contraceptives and provide an analysis of safety data between oral contraceptives and incretin agents. METHODS: PubMed and Google Scholar were searched using the generic name for the GLP-1/GIP agent, the generic names for GLP-1 RAs and hormonal contraceptives, followed by the generic names plus the interacting medication. A total of 6 clinical trials were selected for inclusion in the literature review. RESULTS: Of the 6 articles included in the review, one investigated the use of tirzepatide and showed a statistically significant reduction in area under the plasma drug concentration-time curve, maximum concentration, and time to maximum plasma concentration when tirzepatide was concomitantly administered with an oral hormonal contraceptive. The remaining 5 studies involving GLP-1 RAs did not show a statistically or clinically significant difference of impact of the agents on oral hormonal contraceptives. CONCLUSION: It could be suggested that tirzepatide had a greater impact on absorption of oral hormonal contraceptives than other GLP-1 RAs. The rapid dose escalation and greater delay on GE enhanced the impact on oral medications such as contraceptives. This differed from other GLP-1 RAs and creates a unique need for enhanced provider and patient education regarding the management of this interaction and future studies to evaluate this interaction further.

Impact of a pharmacist-driven COPD clinic on outcomes related to COPD in a federally qualified health center.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) affects many patients across the United States. Morbidity related to COPD can lead to increased financial strain to health care system. The United States is also shifting toward value-based payments, which rely on satisfying quality measures. Pharmacists are equipped with knowledge in adjusting medications based on symptom burden and guideline recommendations in COPD and are equipped with the proper knowledge to address quality measures. OBJECTIVE: This project aimed to determine the impact of a clinical pharmacy service centered around inhaler education and optimization on COPD morbidity and Uniform Data System (UDS) quality measure satisfaction in a federally qualified health center. METHODS: This quality improvement project consisted of patient referrals by and reports from a population health software for the pharmacy service from November 2022 to March 2023. The outcomes in this study included symptom change measured by follow-up modified Medical Research Council (mMRC) Dyspnea Scale in addition to changes in compliance with UDS quality measures. At follow-up, patients were administered another mMRC to evaluate treatment effect and determine quality measure satisfaction. RESULTS: Thirteen patient visits were conducted. Most patients were female (84.6%) with an exacerbation in the previous year (46.1%). All patients received an adjustment in their pharmacotherapy along with inhaler education. The average baseline mMRC score decreased from 2.1 to 0.6, indicating a decrease in overall COPD symptoms. Five quality measures of 13 were satisfied during the follow-up period. CONCLUSION: The COPD clinical pharmacy service led to an increase in guideline-driven pharmacotherapy regimens for patients with COPD while having an overall decrease in morbidity. Quality measures were also addressed and satisfied after the appointment. Continuation of this quality improvement service will ensure proper assessment of COPD along with addressing UDS quality measures.

What kind of illness is anorexia nervosa? Revisited: some preliminary thoughts to finding a cure.

Two decades have elapsed since our publication of 'What kind of illness is anorexia nervosa?'. The question remains whether our understanding of anorexia nervosa and its treatment thereof has evolved over this time. The verdict is disappointing at best. Our current gold standard treatments remain over-valued and clinical outcomes are modest at best. Those in our field are haunted by the constant reminder that anorexia nervosa carries the highest mortality rate of any psychiatric disorder. This cannot continue and demands immediate action. In this essay, we tackle the myths that bedevil our field and explore a deeper phenotyping of anorexia nervosa. We argue that we can no longer declare agnostic views of the disorder or conceive treatments that are "brainless": it is incumbent upon us to challenge the prevailing zeitgeist and reconceptualise anorexia nervosa. Here we provide a roadmap for the future.

Adjunctive technologies in postoperative free-flap monitoring: a systematic review.

Patent microvascular anastomoses are essential for successful free tissue transfer. Early accurate detection of microvascular compromise is required for flap salvage. Adjunctive monitoring techniques, in addition to clinical examination, are increasingly used to detect flap compromise. This systematic review synthesized and appraised the literature to determine the efficacy of different postoperative monitoring technologies. Rates of flap takeback, salvage, failure, and mean time to detection of microvascular compromise were extracted, synthesized, and reviewed. Twenty-two studies were included, comprising 6370 flaps. One thousand three hundred and ninety-five flaps were monitored with Cook Swartz Doppler (21.83%), 1417 flaps with tissue oximetry (22.24%), 291 with laser Doppler (4.56%), 175 with duplex echography (2.74%), 210 with indocyanine green (ICG) fluorescence (3.30%), 196 with Synovis flow coupler (3.07%), and 81 (1.27%) with light spectroscopy. The overall true positive rate for microvascular compromise in taken back flaps was 70.18%. Cook Swartz Doppler (n = 1391) had a true positive rate of 80.17% and 83.63% salvage rate and was associated with an overall 2.60% rate of flap failure. Tissue oximetry (n = 1417) had a true positive rate of 74.76% and a salvage rate of 88.62%. Laser Doppler, duplex echography, light spectroscopy, and Synovis flow coupler demonstrated true positive rates between 69.4% and 100% with salvage rates between 64% and 100%. Cook Swartz Doppler and tissue oximetry are associated with prompt identification of microvascular compromise and return to theatre. Alternative modalities, including near-infrared spectroscopy, laser Doppler, and duplex echography, show promise. Further well-designed randomised controlled trials (RCTs) appraising head-to-head efficacy are required to comparatively assess adjunctive technologies.

Patterns of objectively measured physical activity differ between men living with and without HIV.

OBJECTIVE: To use accelerometers to quantify differences in physical activity (PA) by HIV serostatus and HIV viral load (VL) in the Multicenter AIDS Cohort Study (MACS). METHODS: MACS participants living with (PLWH, n = 631) and without (PWOH, n = 578) HIV wore an ambulatory electrocardiogram monitor containing an accelerometer for 1-14 days. PA was summarized as cumulative mean absolute deviation (MAD) during the 10 most active consecutive hours (M10), cumulative MAD during the six least active consecutive hours (L6), and daily time recumbent (DTR). PA summaries were compared by HIV serostatus and by detectability of VL (>20 vs. ≤20 copies/ml) using linear mixed models adjusted for sociodemographics, weight, height, substance use, physical function, and clinical factors. RESULTS: In sociodemographic-adjusted models, PLWH with a detectable VL had higher L6 (ß = 0.58 mg, P = 0.027) and spent more time recumbent (ß = 53 min/day, P = 0.003) than PWOH. PLWH had lower M10 than PWOH (undetectable VL ß = -1.62 mg, P = 0.027; detectable VL ß = -1.93 mg, P = 0.12). A joint test indicated differences in average PA measurements by HIV serostatus and VL (P = 0.001). However, differences by HIV serostatus in M10 and DTR were attenuated and no longer significant after adjustment for renal function, serum lipids, and depressive symptoms. CONCLUSIONS: Physical activity measures differed significantly by HIV serostatus and VL. Higher L6 among PLWH with detectable VL may indicate reduced amount or quality of sleep compared to PLWH without detectable VL and PWOH. Lower M10 among PLWH indicates lower amounts of physical activity compared to PWOH.

Fungal Planet description sheets: 1042-1111.

Novel species of fungi described in this study include those from various countries as follows: Antarctica, Cladosporium arenosum from marine sediment sand. Argentina, Kosmimatamyces alatophylus (incl. Kosmimatamyces gen. nov.) from soil. Australia, Aspergillus banksianus, Aspergillus kumbius, Aspergillus luteorubrus, Aspergillus malvicolor and Aspergillus nanangensis from soil, Erysiphe medicaginis from leaves of Medicago polymorpha, Hymenotorrendiella communis on leaf litter of Eucalyptus bicostata, Lactifluus albopicri and Lactifluus austropiperatus on soil, Macalpinomyces collinsiae on Eriachne benthamii, Marasmius vagus on soil, Microdochium dawsoniorum from leaves of Sporobolus natalensis, Neopestalotiopsis nebuloides from leaves of Sporobolus elongatus, Pestalotiopsis etonensis from leaves of Sporobolus jacquemontii, Phytophthora personensis from soil associated with dying Grevillea mccutcheonii. Brazil, Aspergillus oxumiae from soil, Calvatia baixaverdensis on soil, Geastrum calycicoriaceum on leaf litter, Greeneria kielmeyerae on leaf spots of Kielmeyera coriacea. Chile, Phytophthora aysenensis on collar rot and stem of Aristotelia chilensis. Croatia, Mollisia gibbospora on fallen branch of Fagus sylvatica. Czech Republic, Neosetophoma hnaniceana from Buxus sempervirens. Ecuador, Exophiala frigidotolerans from soil. Estonia, Elaphomyces bucholtzii in soil. France, Venturia paralias from leaves of Euphorbia paralias. India, Cortinarius balteatoindicus and Cortinarius ulkhagarhiensis on leaf litter. Indonesia, Hymenotorrendiella indonesiana on Eucalyptus urophylla leaf litter. Italy, Penicillium taurinense from indoor chestnut mill. Malaysia, Hemileucoglossum kelabitense on soil, Satchmopsis pini on dead needles of Pinus tecunumanii. Poland, Lecanicillium praecognitum on insects' frass. Portugal, Neodevriesia aestuarina from saline water. Republic of Korea, Gongronella namwonensis from freshwater. Russia, Candida pellucida from Exomias pellucidus, Heterocephalacria septentrionalis as endophyte from Cladonia rangiferina, Vishniacozyma phoenicis from dates fruit, Volvariella paludosa from swamp. Slovenia, Mallocybe crassivelata on soil. South Africa, Beltraniella podocarpi, Hamatocanthoscypha podocarpi, Coleophoma podocarpi and Nothoseiridium podocarpi (incl. Nothoseiridium gen. nov.) from leaves of Podocarpus latifolius, Gyrothrix encephalarti from leaves of Encephalartos sp., Paraphyton cutaneum from skin of human patient, Phacidiella alsophilae from leaves of Alsophila capensis, and Satchmopsis metrosideri on leaf litter of Metrosideros excelsa. Spain, Cladophialophora cabanerensis from soil, Cortinarius paezii on soil, Cylindrium magnoliae from leaves of Magnolia grandiflora, Trichophoma cylindrospora (incl. Trichophoma gen. nov.) from plant debris, Tuber alcaracense in calcareus soil, Tuber buendiae in calcareus soil. Thailand, Annulohypoxylon spougei on corticated wood, Poaceascoma filiforme from leaves of unknown Poaceae. UK, Dendrostoma luteum on branch lesions of Castanea sativa, Ypsilina buttingtonensis from heartwood of Quercus sp. Ukraine, Myrmecridium phragmiticola from leaves of Phragmites australis. USA, Absidia pararepens from air, Juncomyces californiensis (incl. Juncomyces gen. nov.) from leaves of Juncus effusus, Montagnula cylindrospora from a human skin sample, Muriphila oklahomaensis (incl. Muriphila gen. nov.) on outside wall of alcohol distillery, Neofabraea eucalyptorum from leaves of Eucalyptus macrandra, Diabolocovidia claustri (incl. Diabolocovidia gen. nov.) from leaves of Serenoa repens, Paecilomyces penicilliformis from air, Pseudopezicula betulae from leaves of leaf spots of Populus tremuloides. Vietnam, Diaporthe durionigena on branches of Durio zibethinus and Roridomyces pseudoirritans on rotten wood. Morphological and culture characteristics are supported by DNA barcodes.

HIV Infection Is Associated With Variability in Ventricular Repolarization: The Multicenter AIDS Cohort Study (MACS).

BACKGROUND: People living with human immunodeficiency virus (HIV+) have greater risk for sudden arrhythmic death than HIV-uninfected (HIV-) individuals. HIV-associated abnormal cardiac repolarization may contribute to this risk. We investigated whether HIV serostatus is associated with ventricular repolarization lability by using the QT variability index (QTVI), defined as a log measure of QT-interval variance indexed to heart rate variance. METHODS: We studied 1123 men (589 HIV+ and 534 HIV-) from MACS (Multicenter AIDS Cohort Study), using the ZioXT ambulatory electrocardiography patch. Beat-to-beat analysis of up to 4 full days of electrocardiographic data per participant was performed using an automated algorithm (median analyzed duration [quartile 1-quartile 3]: 78.3 [66.3-83.0] hours/person). QTVI was modeled using linear mixed-effects models adjusted for demographics, cardiac risk factors, and HIV-related and inflammatory biomarkers. RESULTS: Mean (SD) age was 60.1 (11.9) years among HIV- and 54.2 (11.2) years among HIV+ participants (P<0.001), 83% of whom had undetectable (<20 copies/mL) HIV-1 viral load (VL). In comparison with HIV- men, HIV+ men had higher QTVI (adjusted difference of +0.077 [95% CI, +0.032 to +0.123]). The magnitude of this association depended on the degree of viremia, such that in HIV+ men with undetectable VL, adjusted QTVI was +0.064 (95% CI, +0.017 to +0.111) higher than in HIV- men, whereas, in HIV+ men with detectable VL, adjusted QTVI was higher by +0.150 (95% CI, 0.072-0.228) than in HIV- referents. Analysis of QTVI subcomponents showed that HIV+ men had: (1) lower heart rate variability irrespective of VL status, and (2) higher QT variability if they had detectable, but not with undetectable, VL, in comparison with HIV- men. Higher levels of C-reactive protein, interleukin-6, intercellular adhesion molecule-1, soluble tumor necrosis factor receptor 2, and soluble cluster of differentiation-163 (borderline), were associated with higher QTVI and partially attenuated the association with HIV serostatus. CONCLUSIONS: HIV+ men have greater beat-to-beat variability in QT interval (QTVI) than HIV- men, especially in the setting of HIV viremia and heightened inflammation. Among HIV+ men, higher QTVI suggests ventricular repolarization lability, which can increase susceptibility to arrhythmias, whereas lower heart rate variability signals a component of autonomic dysfunction.

Empirical examination of the interpersonal maintenance model of anorexia nervosa.

OBJECTIVE: A cognitive interpersonal maintenance model of anorexia nervosa (AN) was first proposed in 2006 and updated in 2013 (Schmidt and Treasure, J Br J Clin Psychol, 45, 343-366, 2006; Treasure and Schmidt, J Eat Disorders, in press.). The aim of this study was to test the interpersonal component of this model in people with AN requiring intensive hospital treatment (inpatient/day patient). METHOD: On admission to hospital women with AN or eating disorder not otherwise specified (AN subtype; n = 152; P) and their primary carers (n = 152; C) completed questionnaires on eating symptoms (P), depression and anxiety (P, C), accommodation and enabling (C), and psychological control (C). Structural equation modeling was used to examine relationships among these components. RESULTS: Carers' expressed emotion and level of psychological control were significantly related to carers' distress, which in turn, was related to patients' distress. This pathway significantly predicted eating symptoms in patients. DISCUSSION: The cognitive interpersonal maintenance model of eating disorders (EDs) was confirmed in part and suggests that interventions targeting interpersonal maintaining factors such as carer distress might impact on patient outcomes.

Treating severe and enduring anorexia nervosa: a randomized controlled trial.

BACKGROUND: There are no evidence-based treatments for severe and enduring anorexia nervosa (SE-AN). This study evaluated the relative efficacy of cognitive behavioral therapy (CBT-AN) and specialist supportive clinical management (SSCM) for adults with SE-AN. METHOD: Sixty-three participants with a diagnosis of AN, who had at least a 7-year illness history, were treated in a multi-site randomized controlled trial (RCT). During 30 out-patient visits spread over 8 months, they received either CBT-AN or SSCM, both modified for SE-AN. Participants were assessed at baseline, end of treatment (EOT), and at 6- and 12-month post-treatment follow-ups. The main outcome measures were quality of life, mood disorder symptoms and social adjustment. Weight, eating disorder (ED) psychopathology, motivation for change and health-care burden were secondary outcomes. RESULTS: Thirty-one participants were randomized to CBT-AN and 32 to SSCM with a retention rate of 85% achieved at the end of the study. At EOT and follow-up, both groups showed significant improvement. There were no differences between treatment groups at EOT. At the 6-month follow-up, CBT-AN participants had higher scores on the Weissman Social Adjustment Scale (WSAS; p = 0.038) and at 12 months they had lower Eating Disorder Examination (EDE) global scores (p = 0.004) and higher readiness for recovery (p = 0.013) compared to SSCM. CONCLUSIONS: Patients with SE-AN can make meaningful improvements with both therapies. Both treatments were acceptable and high retention rates at follow-up were achieved. Between-group differences at follow-up were consistent with the nature of the treatments given.

An outbreak of infectious syphilis among young heterosexuals in an English town.

We describe a recent outbreak of syphilis in young heterosexuals in the north west of England. A cluster of 12 cases of syphilis (7 primary and 5 early latent) was identified in Rochdale in heterosexuals aged 20 or under. Nine were women. Five were asymptomatic at presentation. This outbreak occurred in a group not usually associated with syphilis transmission in the north west. Not all the identified cases could be linked, and so potentially this outbreak is a sentinel of a larger problem.

The potential impact of decision role and patient age on end-of-life treatment decision making.

BACKGROUND: Recent research demonstrates that people sometimes make different medical decisions for others than they would make for themselves. This finding is particularly relevant to end-of-life decisions, which are often made by surrogates and require a trade-off between prolonging life and maintaining quality of life. We examine the impact of decision role, patient age, decision maker age and multiple individual differences on these treatment decisions. METHODS: Participants read a scenario about a terminally ill cancer patient faced with a choice between an aggressive chemotherapy regimen that will extend life by two years and palliative treatments to control discomfort for one remaining month. Participants were randomly assigned to one of three decision roles (patient, physician, or an abstract other) and the scenario randomly varied whether the patient was described as 25 or 65-years old. RESULTS: When deciding for a 65-year old patient, approximately 60% of participants selected aggressive chemotherapy regardless of decision role. When deciding for a 25-year old patient, however, participants were more likely to select chemotherapy for a patient (physician role) or another person (abstract other) than for themselves (70%, 67%, and 59%, respectively). In addition, confidence that powerful others (eg, physicians) control one's health, as well as respondents' age and race, consistently predicted treatment choices. CONCLUSIONS: Patient age appears to influence medical decisions made for others but not those that we make for ourselves. These findings may help to explain the discord that often occurs when younger cancer patients refuse life-extending treatments.

Effects of oxygen on cell turnover and expression of regulators of apoptosis in human placental trophoblast.

Pre-eclampsia (PE) and intrauterine growth restriction (IUGR) are associated with aberrant cell turnover, including increased apoptosis, in placental villous trophoblast. The increased apoptosis is associated with exaggerated expression of p53, which promotes cell cycle arrest or apoptosis via downstream proteins such as p21 or Bax. These changes in apoptosis and p53 expression are purported to result from exposure to altered oxygen tension. Using a model of villous trophoblast turnover, we examined the effect of 20%, 6% and 1% ambient oxygen (O(2)) on apoptosis, necrosis, proliferation and expression of p53 and related regulators of cell turnover, compared to both fresh tissue. Altered O(2) tension exerted an effect on cell turnover in cultured term villous tissue: cytotrophoblast proliferation was increased by culture in 20% O(2) and reduced in 1% O(2) (median proliferative index: fresh tissue=0.32%, 20% O(2)=0.9%, 6% O(2)=0.28%, 1% O(2)=0.07%). Apoptosis was increased in all culture environments, but was significantly enhanced by culture in 1% O(2) (median apoptotic index: fresh tissue=0.64%, 20% O(2)=2.96%, 6% O(2)=3.81%, 1% O(2)=9.2%). Necrotic cell death was also increased by culture in 1% O(2) compared to 6% and 20% O(2). The expression of p53, p21 and Mdm2 in both cytotrophoblast and stromal cells was increased following culture in 1% O(2). There was no alteration in the expression of Bax or Bcl-2. This study provides evidence that p53 is elevated in trophoblast following exposure to hypoxia. The potential role of the p53-pathway in the control of cell turnover in villous trophoblast and the regulation of p53 by altered O(2) tension merits further investigation.

Parotid gland enlargement in eating disorders: an insensitive sign?

OBJECTIVE: To study, using magnetic resonance imaging (MRI), the parotid glands of patients who self-induce vomiting and in particular to observe the effects of cessation of this behaviour. The morphological features and composition of enlarged parotid glands in this group, compared with normal controls, were also examined. METHOD: MRI scans of the parotid glands were performed on 5 controls and 5 subjects with a purging form of eating disorder, at cessation of vomiting and 6 to 9 weeks later. RESULTS: Parotid volumes are accurately measured using MRI. Enlarged parotids are not a consistent feature of subjects with eating disorders who self-induce vomiting. CONCLUSION: Absence of salivary gland enlargement does not exclude significant vomiting behaviour and clinicians should remain alert to the possibility of undisclosed vomiting.

The extent and variability of effects of culture conditions on the secretion of human chorionic gonadotrophin and interleukin-6 by human, term placental explants in culture.

Culture of explants derived from third trimester human placenta is used in a range of contexts as an experimental model that retains tissue architecture. This study aimed to explore the variability between, and within, individuals of secretion by explants of human chorionic gonadotrophin (hCG) and interleukin-6 (IL-6). Standard culture medium contained hydrocortisone, insulin, retinoic acid and serum. Under these conditions explants displayed significant differences in the time-course and extent of hCG secretion. Peak hCG secretion varied between 1.19 and 242 mIU/mg protein/h (coefficient of variation (CV) = 111%) and could occur between days 4 and 7 of culture. hCG secretion was more variable if explant protein was < 400 microg. Unadjusted day 7 hCG secretion showed marked variation: intra-placental CV = 15%, inter-placental CV = 86%. When day 7 hCG secretion was standardised by day 6 secretion, intra-placental CV was 6.9%, inter-placental CV was 4.0%. When this standardisation was applied, hCG secretion during day 7 of culture was not affected by removal of hydrocortisone, insulin or serum from the medium or by the addition of tumour necrosis factor-alpha (TNF-alpha). The secretion of IL-6 during day 7 of culture (standardised by taking natural logarithms) was increased markedly by the addition of TNF-alpha but unaltered by removing hydrocortisone, insulin or serum. Thus, we have shown that although variable, secretion by placental explants can be used to investigate how placental tissue adapts to different culture conditions. However, explants of the same protein content may have markedly different secretory properties.

SNAT4 isoform of system A amino acid transporter is expressed in human placenta.

The system A amino acid transporter is encoded by three members of the Slc38 gene family, giving rise to three subtypes: Na+-coupled neutral amino acid transporter (SNAT)1, SNAT2, and SNAT4. SNAT2 is expressed ubiquitously in mammalian tissues; SNAT1 is predominantly expressed in heart, brain, and placenta; and SNAT4 is reported to be expressed solely by the liver. In the placenta, system A has an essential role in the supply of neutral amino acids needed for fetal growth. In the present study, we examined expression and localization of SNAT1, SNAT2, and SNAT4 in human placenta during gestation. Real-time quantitative PCR was used to examine steady-state levels of system A subtype mRNA in early (6-10 wk) and late (10-13 wk) first-trimester and full-term (38-40 wk) placentas. We detected mRNA for all three isoforms from early gestation onward. There were no differences in SNAT1 and SNAT2 mRNA expression with gestation. However, SNAT4 mRNA expression was significantly higher early in the first trimester compared with the full-term placenta (P < 0.01). We next investigated SNAT4 protein expression in human placenta. In contrast to the observation for gene expression, Western blot analysis revealed that SNAT4 protein expression was significantly higher at term compared with the first trimester (P < 0.05). Immunohistochemistry and Western blot analysis showed that SNAT4 is localized to the microvillous and basal plasma membranes of the syncytiotrophoblast, suggesting a role for this isoform of system A in amino acid transport across the placenta. This study therefore provides the first evidence of SNAT4 mRNA and protein expression in the human placenta, both at the first trimester and at full term.

E-cadherin in the assessment of aberrant placental cytotrophoblast turnover in pregnancies complicated by pre-eclampsia.

E-cadherin is a cell-cell adhesion protein expressed in cytotrophoblasts, which is lost as they differentiate and syncytialise. We have exploited E-cadherin as a marker of cytotrophoblasts to investigate villous tissue composition in first and third trimester placentae, both in normal pregnancy and pregnancies complicated by pre-eclampsia. We have achieved this by measuring expression levels of E-cadherin at the mRNA level, using Q-PCR, and at the protein level using semi-quantitative Western blotting. We have also combined E-cadherin immunohistochemistry with morphometric analysis of area measurements to define cytotrophoblast and syncytiotrophoblast compartments. This novel use of E-cadherin has revealed a decrease in the proportion of cytotrophoblasts in villous tissue as pregnancy progresses, in the absence of changes in syncytiotrophoblast cover. Moreover, in pre-eclampsia, placental E-cadherin was raised compared to syncytiotrophoblast, suggesting either exaggerated cytotrophoblast proliferation or impaired cytotrophoblast differentiation, both alterations of potential pathogenic importance.

Gestational profile of Na+/H+ exchanger and Cl-/HCO3- anion exchanger mRNA expression in placenta using real-time QPCR.

The onset of maternal blood flow (10-12 weeks gestation) results in increased oxygenation of the placenta. We investigated whether the expressions of Na+/H+ exchanger (NHE) and Cl-/HCO3- anion exchanger (AE), thought to have an important role in maintaining intracellular pH of the syncytiotrophoblast and fetal pH homeostasis, are altered at the same time as this increase in blood flow. Real-time quantitative PCR was used to examine steady state levels of NHE (NHE1, 2, 3) and AE (AE1, 2) mRNA expression in early (6-9 weeks) and late (10-13 weeks) first trimester and full-term (38-40 weeks) placentas. beta-Actin, IF2B and GAPDH mRNA was also measured. None of the genes showed a significant difference in expression between the early and late first trimester groups. However, NHE2 (p < 0.001) and GAPDH (p < 0.05) mRNA expression significantly increased 18- and 3.7-fold between early first trimester and term. In conclusion, this study provides additional evidence that GAPDH is an unsuitable housekeeping gene for normalization of transcript levels in placenta. The expression of NHE and AE in the villous placenta is not altered concomitant with the onset of maternal blood flow. However, NHE2 transcripts appear to be gestationally regulated, which may contribute to changes in NHE activity.