Knowledge, attitudes and practice towards postoperative nursing of patients with digit replantation and skin flap transplantation among new nurses in Beijing: a cross-sectional survey

OBJECTIVE

To explore the knowledge, attitudes and practice (KAP) towards the postoperative nursing of patients with digit replantation and skin flap transplantation among new nurses.

DESIGN

Cross-sectional survey.

SETTING

Two tertiary medical centres in Beijing, China.

PARTICIPANTS

New nurses with working experience within 2 years.

PRIMARY AND SECONDARY OUTCOME MEASURES

The demographic characteristics of the nurses and their KAP towards the postoperative nursing of patients with digit replantation and skin flap transplantation were collected using a self-administered questionnaire. The primary outcome was the KAP scores towards the postoperative nursing of patients with digit replantation and skin flap transplantation. The secondary outcomes were the factors associated with the KAP scores and how the KAP dimensions interacted among them.

RESULTS

A total of 206 valid questionnaires were collected. The mean KAP scores were 7.72±3.28 (total score 13; 59.3%), 37.95±6.05 (total score 50; 75.9%) and 38.23±6.12 (total score 45; 84.9%), indicating poor knowledge, moderately favourable attitudes and active practice. The structural equation model analysis showed that knowledge directly influences attitudes (β=0.82, 95%CI 0.60 to 1.05, p<0.001) and that attitudes directly influence practices (β=0.72, 95%CI 0.62 to 0.83, p<0.001). Knowledge had no direct influence on practices (β=0.10, 95%CI -0.09 to 0.29, p=0.313), but the indirect influence was significant (β=0.60, 95%CI 0.41 to 0.78, p<0.001).

CONCLUSION

The lack of sufficient knowledge towards the postoperative nursing of patients with digit replantation and skin flap transplantation among nurses with <2 years of experience and the correlation among the KAP dimensions suggested the importance of proper training.

Relationship between climate change and skin cancer and implications for prevention and management: a scoping review

OBJECTIVES

This study aimed to explore the published research on the relationship between climate change and skin cancer and the implications for prevention, management and further research.

STUDY DESIGN

Scoping review.

METHODS

This scoping review following JBI methodology reviewed English articles identified in searches of MEDLINE, Embase, CINAHL, Web of Science and Scopus on 14 April 2023. The screening of articles was completed by two independent reviewers. Data were extracted by a single reviewer and checked by another. A causal pathway diagram was iteratively developed throughout the review and was used to categorise the findings.

RESULTS

The search identified 1376 papers, of which 45 were included in the final review. Nine papers reported primary research, and 36 papers were reviews, perspectives, commentaries, editorials, or essays. The papers examined climate change influencing behaviours related to ultraviolet exposure (30 papers), ambient temperature (21 papers) and air pollution (five papers) as possible risk factors; occupational, rural, and contextual factors affecting skin cancer (11 papers); and prevention and access to health care in the context of climate change (seven papers). Most papers were published in journals in subject areas other than health.

CONCLUSIONS

This review identified ultraviolet radiation, occupation, rising temperature, individual behaviour and air pollution as possible influences on skin cancer rates. Furthermore, it highlights the complexity and uncertainties in the relationship between climate change and skin cancer and the need for further research on this relationship, including primary epidemiological research and reviews that follow recognised review guidelines and include assessment of health services and social determinants in the causal pathways of this relationship.

Molecular architecture of the ciliary tip revealed by cryo-electron tomography

Cilia are essential organelles that protrude from the cell body. Cilia are made of a microtubule-based structure called the axoneme. In most types of cilia, the ciliary tip is distinct from the rest of the cilium. Here, we used cryo-electron tomography and subtomogram averaging to obtain the structure of the ciliary tip of the ciliate Tetrahymena thermophila. We show the microtubules in the tip are highly cross-linked with each other and stabilised by luminal proteins, plugs and cap proteins at the plus ends. In the tip region, the central pair lacks the typical projections and twists significantly. By analysing cells lacking a ciliary tip-enriched protein CEP104/FAP256 by cryo-electron tomography and proteomics, we discovered candidates for the central pair cap complex and explain potential functions of CEP104/FAP256. These data provide new insights into the function of the ciliary tip and inform about the mechanisms of ciliary assembly and length regulation.

Prognostic implication of the neoadjuvant rectal score and other biomarkers of clinical outcome in Hong Kong Chinese patients with locally advanced rectal cancer undergoing neoadjuvant chemoradiotherapy

BACKGROUND

Neoadjuvant chemoradiotherapy is a standard treatment for locally advanced rectal cancer, for which pathological complete response is typically used as a surrogate survival endpoint. Neoadjuvant rectal score is a new biomarker that has been shown to correlate with survival. The main objectives of this study were to investigate factors contributing to pathological complete response, to validate the prognostic significance of neoadjuvant rectal score, and to investigate factors associated with a lower neoadjuvant rectal score in a cohort of Hong Kong Chinese.

METHODS

Data of patients with locally advanced rectal cancer who received neoadjuvant chemoradiotherapy from August 2006 to October 2018 were retrieved from hospital records and retrospectively analysed.

RESULTS

Of 193 patients who had optimal response to neoadjuvant chemoradiotherapy and surgery, tumour down-staging was the only independent prognostic factor that predicted pathological complete response (P<0.0001). Neoadjuvant rectal score was associated with overall survival (hazard ratio [HR]=1.042, 95% confidence interval [CI]=1.021-1.064; P<0.0001), disease-free survival (HR=1.042, 95% CI=1.022-1.062; P<0.0001), locoregional recurrence-free survival (HR=1.070, 95% CI=1.039-1.102; P<0.0001) and distant recurrence-free survival (HR=1.034, 95% CI=1.012-1.056; P=0.002). Patients who had pathological complete response were associated with a lower neoadjuvant rectal score (P<0.0001), but pathological complete response was not associated with survival. For patients with intermediate neoadjuvant rectal scores, late recurrences beyond 72 months from diagnosis were observed.

CONCLUSION

Neoadjuvant rectal score is an independent prognostic marker of survival and disease recurrence in a cohort of Hong Kong Chinese patients who received neoadjuvant chemoradiotherapy for locally advanced rectal cancer.

Ultrafast Transient Spectroscopy of Trans-Polyacetylene in the Midinfrared Spectral Range

Trans-polyacetylene [t-(CH)_{x}] possesses twofold ground state degeneracy. Using the Su-Schrieffer-Heeger Hamiltonian, scientists predicted charged solitons to be the primary photoexcitations in t-(CH)_{x}; this prediction, however, has led to sharp debate. To resolve this saga, we use subpicosecond transient photomodulation spectroscopy in the mid-IR spectral range (0.1-1.5 eV) in neat t-(CH)_{x} thin films. We show that odd-parity singlet excitons are the primary photoexcitations in t-(CH)_{x}, similar to many other nondegenerate π-conjugated polymers. The exciton transitions are characterized by two photoinduced absorption (PA) bands at 0.38 and 0.6 eV, and an associated photoluminescence band at ∼1.5  eV having similar polarization memory. The primary excitons undergo internal conversion within ∼100  fs to an even-parity (dark) singlet exciton with a PA band at ∼1.4  eV. We also find ultrafast photogeneration of charge polarons when pumping deep into the polymer continuum band, which are characterized by two other PA bands in the mid-IR and associated photoinduced IR vibrational modes.

Factors associated with food insecurity among older homeless adults: results from the HOPE HOME study

BACKGROUND

The US homeless population is aging. Older adults and those living in poverty are at a high risk of food insecurity.

METHODS

We conducted a cross-sectional analysis of baseline data from a population-based study of 350 homeless adults aged ≥50. We assessed food security and receipt of food assistance. We used multivariable logistic regression to examine factors associated with very low food security.

RESULTS

The majority of the cohort was male and African American. Over half (55.4%) met criteria for food insecurity, 24.3% reported very low food security. Half (51.7%) reported receiving monetary food assistance. In the multivariable model, those who were primarily sheltered in the prior 6 months, (multi-institution users [AOR = 0.44, 95% CI: 0.22-0.86]) had less than half the odds of very low food security compared with those who were unsheltered. Depressive symptoms (AOR = 3.01, 1.69-5.38), oral pain (AOR = 2.15, 1.24-3.74) and cognitive impairment (AOR = 2.21, 1.12-4.35) were associated with increased odds of very low food security.

CONCLUSIONS

Older homeless adults experience a high prevalence of food insecurity. To alleviate food insecurity in this population, targeted interventions must address specific risk groups.

Therapeutic Advantages of Dual Targeting of PPAR-δ and PPAR-γ in an Experimental Model of Sporadic Alzheimer's Disease

Background:

Alzheimer’s disease (AD) is associated with progressive impairments in brain responsiveness to insulin and insulin-like growth factor (IGF). Although deficiencies in brain insulin and IGF could be ameliorated with trophic factors such as insulin, impairments in receptor expression, binding, and tyrosine kinase activation require alternative strategies. Peroxisome proliferator-activated receptor (PPAR) agonists target genes downstream of insulin/IGF stimulation. Furthermore, their anti-oxidant and anti-inflammatory effects address other pathologies contributing to neurodegeneration.

Objectives:

The goal of this research was to examine effects of dual delivery of L165, 041 (PPAR-δ) and F-L-Leu (PPAR-γ) agonists for remediating in the early stages of neurodegeneration.

Model:

Experiments were conducted using frontal lobe slice cultures from an intracerebral Streptozotocin (i.c. STZ) rat model of AD.

Results:

PPAR-δ+ PPAR-γ agonist treatments increased indices of neuronal and myelin maturation, and mitochondrial proliferation and function, and decreased neuroinflammation, AβPP-Aβ, neurotoxicity, ubiquitin, and nitrosative stress, but failed to restore choline acetyl transferase expression and adversely increased HNE(lipid peroxidation) and acetylcholinesterase, which would have further increased stress and reduced cholinergic function in the STZ brain cultures.

Conclusion:

PPAR-δ + PPAR-γ agonist treatments have substantial positive early therapeutic targeting effects on AD-associated molecular and biochemical brain pathologies. However, additional or alternative strategies may be needed to optimize disease remediation during the initial phases of treatment.

The Differential Effects of Alcohol and Nicotine-Specific Nitrosamine Ketone on White Matter Ultrastructure

Aims

The chronic consumption of alcohol is known to result in neurodegeneration and impairment of cognitive function. Pathological and neuroimaging studies have confirmed that brain atrophy in alcoholics is mainly due to widespread white matter (WM) loss with neuronal loss restricted to specific regions, such as the prefrontal cortex. Neuroimaging studies of cigarette smokers also suggest that chronic inhalation of tobacco smoke leads to brain atrophy, although the neurotoxic component is unknown. As a high proportion of chronic alcoholics also smoke cigarettes it has been hypothesized that at least some alcohol-related brain damage is due to tobacco smoke exposure.

Methods

39 Long Evans rats were subjected to 8 weeks exposure to alcohol and/or 5 weeks co-exposure to nicotine-specific nitrosamine ketone (NNK), a proxy for tobacco smoke. Their frontal WM was then assayed with transmission electron microscopy.

Results

NNK and ethanol co-exposure had a synergistic effect in decreasing myelinated fibre density. Furthermore, NNK treatment led to a greater reduction in myelin sheath thickness than ethanol whereas only the ethanol-treated animals showed a decrease in unmyelinated fibre density.

Conclusion

These data suggest that NNK causes WM degeneration, an effect that is exacerbated by alcohol, but unlike alcohol, it has little impact on the neuronal components of the brain.

Epigenomics alternations and dynamic transcriptional changes in responses to 5-fluorouracil stimulation reveal mechanisms of acquired drug resistance of colorectal cancer cells

A drug-induced resistant cancer cell is different from its parent cell in transcriptional response to drug treatment. The distinct transcriptional response pattern of a drug-induced resistant cancer cell to drug treatment might be introduced by acquired DNA methylation aberration in the cell exposing to sustained drug stimulation. In this study, we performed both transcriptional and DNA methylation profiles of the HCT-8 wild-type cells (HCT-8/WT) for human colorectal cancer (CRC) and the 5-fluorouracil (5-FU)-induced resistant cells (HCT-8/5-FU) after treatment with 5-FU for 0, 24 and 48 h. Integrated analysis of transcriptional and DNA methylation profiles showed that genes with promoter hypermethylation and concordant expression silencing in the HCT-8/5-FU cells are mainly involved in pathways of pyrimidine metabolism and drug metabolism-cytochrome P450. Transcriptional analysis confirmed that genes with transcriptional differences between a drug-induced resistant cell and its parent cell after drug treatment for a certain time, rather than their primary transcriptional differences, are more likely to be involved in drug resistance. Specifically, transcriptional differences between the drug-induced resistant cells and parental cells after drug treatment for 24 h were significantly consistent with the differentially expressed genes (termed as CRG_5-FU) between the tissues of nonresponders and responders of CRCs to 5-FU-based therapy and the consistence increased after drug treatment for 48 h (binomial test, P-value=1.88E−06). This study reveals a major epigenetic mechanism inducing the HCT-8/WT cells to acquire resistance to 5-FU and suggests an appropriate time interval (24–48 h) of 5-FU exposure for identifying clinically relevant drug resistance signatures from drug-induced resistant cell models.

Enzymatic Responses to Alcohol and Tobacco Nicotine-Derived Nitrosamine Ketone Exposures in Long Evans Rat Livers

BACKGROUND

Chronic feeding plus binge administration of ethanol causes very high blood alcohol concentrations. However, its co-administration with tobacco Nicotine-Derived Nitrosamine Ketone (NNK) results in somewhat lower blood alcohol levels, suggesting that NNK and therefore smoking, alters alcohol metabolism in the liver. To explore this hypothesis, we examined effects of ethanol and/or NNK exposures on the expression and activity levels of enzymes that regulate their metabolism in liver.

METHODS

This study utilized a 4-way model in which Long Evans rats were fed liquid diets containing 0% or 26% ethanol for 8 weeks, and respectively i.p injected with saline or 2 g/kg of ethanol 3 times/week during Weeks 7 and 8. The control and ethanol-exposed groups were each sub-divided and further i.p treated with 2 mg/kg of NNK or saline (3×/week) in Weeks 3-8. ADH, catalase and ALDH activities were measured using commercial kits. CYP450 mRNA levels (17 isoforms) were measured by qRT-PCR analysis.

RESULTS

Ethanol significantly increased hepatic ADH but not catalase or ALDH activity. NNK had no effect on ADH, ALDH, or catalase, but when combined with ethanol, it increased ADH activity above the levels measured in all other groups. Ethanol increased CYP2C7, while NNK increased CYP2B1 and CYP4A1mRNA levels relative to control. In contrast, dual ethanol + NNK exposures inhibited CYP2B1 and CYP4A1 expression relative to NNK. Conclusion: Dual exposures to ethanol and NNK increase hepatic ethanol metabolism, and ethanol and/or NNK exposures alter the expression of CYP450 isoforms that are utilized in NNK and fatty acid metabolism.

Multi-omics landscapes of colorectal cancer subtypes discriminated by an individualized prognostic signature for 5-fluorouracil-based chemotherapy

Until recently, few prognostic signatures for colorectal cancer (CRC) patients receiving 5-fluorouracil (5-FU)-based chemotherapy could be used in clinical practice. Here, using transcriptional profiles for a panel of cancer cell lines and three cohorts of CRC patients, we developed a prognostic signature based on within-sample relative expression orderings (REOs) of six gene pairs for stage II-III CRC patients receiving 5-FU-based chemotherapy. This REO-based signature had the unique advantage of being insensitive to experimental batch effects and free of the impractical data normalization requirement. After stratifying 184 CRC samples with multi-omics data from The Cancer Genome Atlas into two prognostic groups using the REO-based signature, we further revealed that patients with high recurrence risk were characterized by frequent gene copy number aberrations reducing 5-FU efficacy and DNA methylation aberrations inducing distinct transcriptional alternations to confer 5-FU resistance. In contrast, patients with low recurrence risk exhibited deficient mismatch repair and carried frequent gene mutations suppressing cell adhesion. These results reveal the multi-omics landscapes determining prognoses of stage II-III CRC patients receiving 5-FU-based chemotherapy.

Increased expression of high mobility group box 1 (HMGB1) in the cytoplasm of placental syncytiotrophoblast from preeclamptic placentae

BACKGROUND

Preeclampsia is a pregnancy-specific disorder characterised by an inappropriate maternal inflammatory response during pregnancy. High mobility group box 1 (HMGB1) was originally characterised as a nuclear protein but when released into the extracellular environment following necrotic cell death, it is proinflammatory. HMGB1 is expressed in the syncytiotrophoblast of human placenta. Higher levels of uric acid are reported in preeclampsia. The aim of this study was to investigate whether the expression of HMGB1differed between early onset and late onset preeclampsia or severe and mild preeclampsia and whether its expression correlated with the levels of uric acid.

METHODS

74 preeclamptic placentae and 110 normotensive placentae were included in this study. The levels of uric acid in women with preeclampsia were measured. The expression of HMGB1 in preeclamptic placentae or in first trimester and term placentae that had been treated with uric acid was measured.

RESULTS

HMGB1 was expressed predominantly in the syncytiotrophoblast of the placenta and the expression of HMGB1 in the cytoplasm of the syncytiotrophoblast was significantly increased in both severe preeclampsia and early onset preeclampsia compared to normotensive pregnancies. The circulating levels of uric acid were significantly increased in preeclampsia and correlated with the expression of HMGB1. Increased levels of HMGB1 were significantly correlated with the severity and the time of onset of preeclampsia, but pathologic levels of uric acid did not increase the expression of HMGB1.

CONCLUSION

Our data provides a better understanding of the function of HMGB1, a danger molecule in the pathogenesis of preeclampsia.

Tobacco Smoke-Induced Hepatic Injury with Steatosis, Inflammation, and Impairments in Insulin and Insulin-Like Growth Factor Signaling

Background

Alcoholic liver disease (ALD) is associated with impairments in hepatic insulin and insulin-like growth factor (IGF) signaling through cell growth, survival, and metabolic pathways. Since not all heavy drinkers develop ALD, co-factors may be important. Epidemiologic data indicate that most heavy drinkers smoke tobacco and experimental data revealed that low-level nitrosamine exposures, including those from tobacco, can cause steatohepatitis with hepatic insulin/IGF resistance and exacerbate ALD. We hypothesize that cigarette smoke (CS) exposures also cause liver injury with impaired hepatic insulin/IGF signaling, and thereby contribute to ALD.

Methods

Adult male A/J mice were exposed to air for 8 weeks (A8), CS for 4 (CS4) or 8 (CS8) weeks, or CS for 8 weeks with 2 weeks recovery (CS8+R).

Results

CS exposures caused progressive liver injury with disruption of the normal hepatic chord architecture, lobular inflammation, apoptosis or necrosis, micro-steatosis, sinusoidal dilatation, and nuclear pleomorphism. Histopathological liver injury scores increased significantly from A8 to CS4 and then further to CS8 (P<0.0001). The mean histological grade was also higher in CS8+R relative to A8 (P<0.0001) but lower than in CS4, reflecting partial resolution of injury by CS withdrawal. CS exposures impaired insulin and IGF-1 signaling through IRS-1, Akt, GSK-3β, and PRAS40. Livers from CS8+R mice had normalized or elevated levels of insulin receptor, pYpY-Insulin-R, 312S-IRS-1, 473S-Akt, S9-GSK-3β, and pT246-PRAS40 relative to A8, CS4, or CS8, reflecting partial recovery.

Conclusion

CS-mediated liver injury and steatohepatitis with impairments in insulin/IGF signalling are reminiscent of the findings in ALD. Therefore, CS exposures (either first or second-hand) may serve as a co-factor in ALD. The persistence of several abnormalities following CS exposure cessation suggests that some aspects of CS-mediated hepatic metabolic dysfunction are not readily reversible.

Flow speed alters the apparent size and concentration of particles measured using NanoSight nanoparticle tracking analysis

Nanoparticle tracking analysis (NTA) is commonly used to count and size nano-sized particles. A sample loading pump can be used to analyse a larger sample volume, but it is unclear whether accuracy is affected. Using a NanoSight NS300 with the manufacturer-supplied pump, we examined synthetic silica and latex microspheres, liposomes and placental extracellular vesicles at different flow speeds. Analysis at flow speeds of 20 or 50 significantly reduced the measured concentration and mean/modal size of particles, particularly for mono-dispersed samples. We identify sample flow speed as a crucial instrument setting which should be reported in all studies that use NTA.

Associations between body mass index and maternal weight gain on the delivery of LGA infants in Chinese women with gestational diabetes mellitus

BACKGROUND

Women with gestational diabetes mellitus (GDM) are at increased risk for maternal and fetal complications including delivery of large for gestational age (LGA) infants. Maternal body mass index (BMI) and excessive weight gain during pregnancy are associated with delivery of LGA infants. However, whether maternal BMI and weight gain are associated with LGA infants in women with GDM is unclear.

BASIC PROCEDURES

Data on 1049 pregnant women who developed GDM were collected from a university teaching hospital in China and retrospectively analyzed. Data included maternal BMI, weight gain, incidence of LGA and gestational week at diagnosis.

MAIN FINDINGS

The incidence of LGA infants was significantly associated with maternal BMI (p=0.0002) in women with GDM. The odds of delivery of LGA for obese or overweight pregnant women are 3.8 or 2 times more than normal weight pregnant women. The incidence of LGA infants was also significantly associated with maternal weight gain in women with GDM. The odds ratio of delivery of LGA for pregnant women with excessive weight gain was 3.3 times more than pregnant women with normal weight gain. The effect of weight gain was not significantly different between different maternal BMI.

PRINCIPAL CONCLUSION

The incidence of delivery of LGA infants in Chinese women with GDM who were overweight or obese is higher than Caucasians, Hispanic, and Asian-Americans. The effects of maternal BMI and weight gain on the delivery of LGA infants by women with GDM are additive.

The anti-inflammatory effect of calcium for preventing endothelial cell activation in preeclampsia

Preeclampsia is a disorder of pregnancy characterized by endothelial activation. It is believed to be a response to a 'toxin(s)' from the placenta including trophoblastic debris and inflammatory cytokines. Calcium is known to reduce the risk of preeclampsia but the mechanism of its protective effect remains unknown. In this study, we investigated the potential mechanism(s) of calcium supplementation for preventing endothelial activation induced by trophoblastic debris. Trophoblastic debris was harvested from preeclamptic placentae and also from first-trimester placentae, which had been treated with preeclamptic sera. Endothelial cells were then cultured with trophoblastic debris in the presence of calcium. Endothelial activation was measured by quantifying endothelial cell-surface intercellular adhesion molecule-1 (ICAM-1) and by U937 monocyte adhesion to endothelial cells. The expression of ICAM-1 and U937 adhesion to endothelial cells were significantly reduced following exposure of endothelial cells to trophoblastic debris from preeclamptic placenta or from first-trimester placentae treated with preeclamptic sera in the presence of calcium compared with treatment without calcium. The expression of ICAM-1 was also significantly reduced following exposure of endothelial cells to trophoblastic debris with the nitric oxide donor or following treatment of endothelial cells with interleukin (IL)-1β in the presence of calcium. Our study demonstrated that calcium supplementation prevented endothelial cell activation induced by trophoblastic debris from preeclamptic placentae. The nitric oxide synthase (NOS) pathway and anti-inflammatory effects are involved in the action of calcium on endothelial cell activation. These findings may suggest, at least in part, the protective mechanism of calcium supplementation on preeclampsia.

Placental extracellular vesicles and feto-maternal communication

The human placenta is an anatomically unique structure that extrudes a variety of extracellular vesicles into the maternal blood (including syncytial nuclear aggregates, microvesicles, and nanovesicles). Large quantities of extracellular vesicles are produced by the placenta in both healthy and diseased pregnancies. Since their first description more than 120 years ago, placental extracellular vesicles are only now being recognized as important carriers for proteins, lipids, and nucleic acids, which may play a crucial role in feto-maternal communication. Here, we summarize the current literature on the cargos of placental extracellular vesicles and the known effects of such vesicles on maternal cells/systems, especially those of the maternal immune and vascular systems.

The Second National Ballistics Imaging Comparison (NBIC-2)

In response to the guidelines issued by the American Society of Crime Laboratory Directors/Laboratory Accreditation Board (ASCLD/LAB-International) to establish traceability and quality assurance in U.S. crime laboratories, NIST and the ATF initiated a joint project, entitled the National Ballistics Imaging Comparison (NBIC). The NBIC project aims to establish a national traceability and quality system for ballistics identifications in crime laboratories utilizing ATF's National Integrated Ballistics Information Network (NIBIN). The original NBIC was completed in 2010. In the second NBIC, NIST Standard Reference Material (SRM) 2461 Cartridge Cases were used as reference standards, and 14 experts from 11 U.S. crime laboratories each performed 17 image acquisitions and correlations of the SRM cartridge cases over the course of about half a year. Resulting correlation scores were collected by NIST for statistical analyses, from which control charts and control limits were developed for the proposed quality system and for promoting future assessments and accreditations for firearm evidence in U.S. forensic laboratories in accordance with the ISO 17025 Standard.

Antiphospholipid antibodies and the placenta: a systematic review of their in vitro effects and modulation by treatment

BACKGROUND

Antiphospholipid antibodies (aPL) are a family of auto-antibodies that are associated with an increased risk of recurrent miscarriage, intrauterine growth restriction and preterm birth. The placenta is a major target of aPL and it is likely that these antibodies promote pregnancy morbidity by affecting trophoblast function. Numerous studies have investigated the effect of aPL on trophoblast function in vitro. However, different trophoblast models and a variety of culture conditions have been employed, resulting in a myriad of different reported findings. This review systematically summarized those published studies that have investigated the effect of aPL on trophoblast function in vitro. In addition, the reported effects of pharmacological treatment on trophoblast function in the presence of aPL were also systematically reviewed.

METHODS

PubMed, Scopus, Embase and Web of Science databases were searched using the keywords 'placenta OR trophoblast' AND 'antiphospholipid antibody OR antiphospholipid syndrome' up to 25 April 2014. Studies were excluded based on the absence of appropriate controls. The effects of aPL on trophoblast proliferation, death, syncytialization, invasion, hormone production, cytokine production, coagulation and complement activation were recorded. The effects of different treatments on the function of trophoblasts in the presence of aPL were also recorded.

RESULTS

A total of 1071 records were retrieved from the four databases. After removing duplicates, the titles and abstracts of 529 articles were reviewed. Of those, 48 articles were read and relevant experimental results were extracted from 47 articles.

CONCLUSIONS

This systematic review provides an overview of all the studies performed to date on the effects of aPL on trophoblast function in vitro. There is considerable support for aPL decreasing trophoblast viability, syncytialization and invasion in vitro. Some work has also suggested that aPL may affect the production of hormones and signalling molecules by trophoblasts, and may stimulate coagulation and complement activation in vitro. Current reports of the in vitro effects of therapeutic treatments on trophoblast function in the presence of aPL are inconclusive. This systematic review has highlighted many gaps in our knowledge of how aPL work and may direct future research in this area.

Ultrafast intersystem-crossing in platinum containing π-conjugated polymers with tunable spin-orbit coupling

The development of efficient organic light-emitting diodes (OLED) and organic photovoltaic cells requires control over the dynamics of spin sensitive excitations. Embedding heavy metal atoms in π-conjugated polymer chains enhances the spin-orbit coupling (SOC), and thus facilitates intersystem crossing (ISC) from the singlet to triplet manifolds. Here we use various nonlinear optical spectroscopies such as two-photon absorption and electroabsorption in conjunction with electronic structure calculations, for studying the energies, emission bands and ultrafast dynamics of spin photoexcitations in two newly synthesized π-conjugated polymers that contain intrachain platinum (Pt) atoms separated by one (Pt-1) or three (Pt-3) organic spacer units. The controllable SOC in these polymers leads to a record ISC time of <~1 ps in Pt-1 and ~6 ps in Pt-3. The tunable ultrafast ISC rate modulates the intensity ratio of the phosphorescence and fluorescence emission bands, with potential applications for white OLEDs.

PP168. The role of calcium supplementation in prevention endothelial cell activation, and possible relevance to preeclampsia

INTRODUCTION

Preeclampsia remains a leading causing of maternal and perinatal mortality and morbidity. Preeclampsia is currently thought to be primarily a disease of endothelial activation and inflammation.

OBJECTIVES

The deportation of trophoblast debris form the placenta was first linked to the pathogenesis of preeclampsia over a hundred years ago and it is hypothesised that deportation of necrotic trophoblast debris may contribute to maternal endothelial cell activation in preeclampsia. We have previously shown that treating placental explants with IL-6 results in shedding of more necrotic trophoblast debris from placental explants and that this debris when phagocytosed by endothelial cells results in activation of the endothelial cells. Although delivery remains the only definitive cure for preeclampsia a number of studies suggest that calcium supplementation may reduce the risk of developing preeclampsia by up to 50% but the protective mechanism of calcium supplementation is unclear. The aim of this work was to determine whether calcium supplementation affects either the production of necrotic trophoblast debris from the placenta or influences endothelial cell activation.

METHODS

First trimester placental explants were cultured with IL-6 in the presence or absence of increasing concentrations of calcium (CaCl2) for 24h. Trophoblastic debris was collected from the explants and then exposed to monolayers of endothelial cell for 24h and endothelial cell activation measured by ICAM-1 ELISA. In other experiments, endothelial cells were treated with IL-6 or necrotic trophoblastic debris in the presence of increasing concentrations of CaCl2, ranging from 230μg/mL to 700μg/mL, for 24h. In some experiments, ebdothelial cells were treated with low concentration of CaCl2, ranging from 0μg/mL to 230μg/mL for 24h. Endothelial cell activation was measured by quantifying cell-surface ICAM-1 levels by ELISA.

RESULTS

CONCLUSION

Our results demonstrate that calcium levels are important to endothelial cell activation and supplemental calcium may reverse the activation of the endothelium induced by proinflammatory mediators while having no effect on the production of trophoblast debris. These results may in part help to explain the benefits of calcium supplementation in the reduction of risk for developing preeclampsia.