Generalized additive models to analyze nonlinear trends in biomedical longitudinal data using R: Beyond repeated measures ANOVA and linear mixed models.

In biomedical research, the outcome of longitudinal studies has been traditionally analyzed using the repeated measures analysis of variance (rm-ANOVA) or more recently, linear mixed models (LMEMs). Although LMEMs are less restrictive than rm-ANOVA as they can work with unbalanced data and non-constant correlation between observations, both methodologies assume a linear trend in the measured response. It is common in biomedical research that the true trend response is nonlinear and in these cases the linearity assumption of rm-ANOVA and LMEMs can lead to biased estimates and unreliable inference. In contrast, GAMs relax the linearity assumption of rm-ANOVA and LMEMs and allow the data to determine the fit of the model while also permitting incomplete observations and different correlation structures. Therefore, GAMs present an excellent choice to analyze longitudinal data with non-linear trends in the context of biomedical research. This paper summarizes the limitations of rm-ANOVA and LMEMs and uses simulated data to visually show how both methods produce biased estimates when used on data with non-linear trends. We present the basic theory of GAMs and using reported trends of oxygen saturation in tumors, we simulate example longitudinal data (2 treatment groups, 10 subjects per group, 5 repeated measures for each group) to demonstrate their implementation in R. We also show that GAMs are able to produce estimates with non-linear trends even when incomplete observations exist (with 40% of the simulated observations missing). To make this work reproducible, the code and data used in this paper are available at: https://github.com/aimundo/GAMs-biomedical-research.

Longitudinal examination of perfusion and angiogenesis markers in primary colorectal tumors shows distinct signatures for metronomic and maximum-tolerated dose strategies.

Metronomic chemotherapy (MET) has been developed to address the shortcomings of maximum-tolerated chemotherapy (MTD) in regard to toxicity and development of resistance mechanisms in the tumor. In colorectal cancer (CRC), MET is a promising novel strategy to treat locally advanced malignancies when used as neoadjuvant chemotherapy (NAC). However, so far there are no preclinical studies to assess the impact of MET NAC in CRC to assess the benefits and challenges of this approach. Here, we used a primary model of CRC (via azoxymethane) to analyze longitudinal changes in angiogenesis in primary tumors under MET and MTD NAC using a combination of diffuse reflectance spectroscopy and mRNA expression (via qPCR). Our results show that MET and MTD NAC lead to increased mean tissue oxygen saturation (8% and 5%, respectively) and oxyhemoglobin (15% and 10%) between weeks 2 and 5 of NAC, and that such increases are caused by distinct molecular signatures in the angiogenic program. Specifically, we find that in the MET group there is a sustained increase in Hif-1a, Aldoa, and Pgk1 expression, suggesting upregulated glycolysis, whereas MTD NAC causes a significant reduction in the expression of the aforementioned genes and of Vegf, leading to vascular remodeling in MTD-treated tumors. Taken together, this study demonstrates the ability of combined optical and molecular methodologies to provide a holistic picture of tumor response to therapy in CRC in a minimally invasive manner.

Minimally invasive in vivo endoscopic monitoring of dextran sulfate sodium-induced murine colitis.

Ulcerative colitis (UC) is a gastrointestinal, autoimmune disease that causes ulceration and inflammation of the colon with an incidence of 10 out of every 100,000 people in North America and Western Europe. Though the specific cause is unknown, several studies have demonstrated that inflammatory cells as well as environmental variables, genetics, and lifestyle behaviors can play a role in the long-term inflammatory response. Researchers have commonly used immunohistochemistry, western blotting and gene sequencing to establish the cellular processes behind UC relapse and remission. However, because these destructive methods necessitate the removal of a sample, they can only be used on non-living tissues. The use of minimally invasive approaches to evaluate the in vivo, longitudinal effects of UC on the mucosa in the colon is gaining popularity among clinicians and researchers. We have created a dextran sulfate sodium-induced model of UC in C57 mice based on the work of Wirtz et al., and a minimally invasive imaging modality to explore the changes in mucosal tissue during "active" and "in remission" UC. Briefly, C57 mice were given dextran sulfate sodium (DSS) dissolved in water in 5-day cycles with a remission/recovery period of 10 days. After 7 days post-DSS treatment and 7 days post-recovery, mice were anesthetized and exploratory endoscopies were performed to assess the mucosal changes that occur during the "active" and "remission" periods of UC. Value of protocol:•Minimally invasive induction of ulcerative colitis in a murine mouse model.•Minimally invasive longitudinal monitoring of "active" and "in remission" ulcerative colitis.•Our endoscopic based imaging modality can be used to validate the induction of ulcerative colitis and the potential treatment response for pre-clinical trials.

Molecular and Serologic Diagnostic Technologies for SARS-CoV-2.

The COVID-19 pandemic has presented many challenges that have spurred biotechnological research to address specific problems. Diagnostics is one area where biotechnology has been critical. Diagnostic tests play a vital role in managing a viral threat by facilitating the detection of infected and/or recovered individuals. From the perspective of what information is provided, these tests fall into two major categories, molecular and serological. Molecular diagnostic techniques assay whether a virus is present in a biological sample, thus making it possible to identify individuals who are currently infected. Additionally, when the immune system is exposed to a virus, it responds by producing antibodies specific to the virus. Serological tests make it possible to identify individuals who have mounted an immune response to a virus of interest and therefore facilitate the identification of individuals who have previously encountered the virus. These two categories of tests provide different perspectives valuable to understanding the spread of SARS-CoV-2. Within these categories, different biotechnological approaches offer specific advantages and disadvantages. Here we review the categories of tests developed for the detection of the SARS-CoV-2 virus or antibodies against SARS-CoV-2 and discuss the role of diagnostics in the COVID-19 pandemic.

Diffuse reflectance spectroscopy to monitor murine colorectal tumor progression and therapeutic response (Erratum).

The erratum notes a correction to Fig. 5 for the published article.

Diffuse reflectance spectroscopy to monitor murine colorectal tumor progression and therapeutic response.

SIGNIFICANCE: Many studies in colorectal cancer (CRC) use murine ectopic tumor models to determine response to treatment. However, these models do not replicate the tumor microenvironment of CRC. Physiological information of treatment response derived via diffuse reflectance spectroscopy (DRS) from murine primary CRC tumors provide a better understanding for the development of new drugs and dosing strategies in CRC. AIM: Tumor response to chemotherapy in a primary CRC model was quantified via DRS to extract total hemoglobin content (tHb), oxygen saturation (StO2), oxyhemoglobin, and deoxyhemoglobin in tissue. APPROACH: A multimodal DRS and imaging probe (0.78 mm outside diameter) was designed and validated to acquire diffuse spectra longitudinally-via endoscopic guidance-in developing colon tumors under 5-fluoruracil (5-FU) maximum-tolerated (MTD) and metronomic regimens. A filtering algorithm was developed to compensate for positional uncertainty in DRS measurements Results: A maximum increase in StO2 was observed in both MTD and metronomic chemotherapy-treated murine primary CRC tumors at week 4 of neoadjuvant chemotherapy, with 21 ± 6 % and 17 ± 6 % fold changes, respectively. No significant changes were observed in tHb. CONCLUSION: Our study demonstrates the feasibility of DRS to quantify response to treatment in primary CRC models.

THE FIRST REPORT OF A CROTALID ENVENOMATION IN A DOMESTICATED FERRET ( MUSTELA FURO) AND SUCCESSFUL TREATMENT WITH A NOVEL F(AB')2 ANTIVENOM.

A case report of a domesticated ferret ( Mustela furo) envenomated by a presumptive rattlesnake ( Crotalus sp.) treated successfully and safely with the novel Fab (2') North American Snake Antivenom (Veteria Labs). The ferret presented with clinical signs of depressed mentation and facial edema following a rattlesnake ( Crotalus sp.) bite. It developed hypotension, thrombocytopenia, and ecchymosis following the envenomation. It was treated with Fab (2') antivenom and given supportive care including crystalloid fluids and analgesia to resolution of clinical signs. This is the first documented case of rattlesnake envenomation in this species. This case supports the efficacy and short-term safety of this Fab (2') antivenom in this species without the use of antihistamines or glucocorticoids. This report also addresses the current standards of care with thorough review of the literature involving rattlesnake envenomation in zoological species.

Systematic review of prostaglandin analogues for retained placenta.

BACKGROUND: Medical management of retained placenta could be a safe alternative to manual removal. OBJECTIVE: To evaluate the efficacy of prostaglandin analogues for retained placenta. SEARCH STRATEGY: MEDLINE, EMBASE, CENTRAL, ICTRP, LILACS, and OpenSIGLE were searched without language restrictions from inception to January 31, 2017, by combining terms for retained placenta and prostaglandin analogues. SELECTION CRITERIA: Randomized controlled trials comparing prostaglandin analogues with any other intervention. DATA COLLECTION AND ANALYSIS: Trials were independently assessed for inclusion, data extraction, and risk of bias. Data were extracted for meta-analyses. GRADE was used to evaluate the quality of data. MAIN RESULTS: Seven randomized controlled trials (851 patients) were included. Prostaglandins did not increase the placenta expulsion rate (relative risk [RR] 1.40, 95% confidence interval [CI] 0.83-2.36) or decrease maternal transfusion (RR 0.72, 95% CI 0.43-1.22). In comparison with oxytocin, prostaglandins did not modify the expulsion rate (RR 1.26, 95% CI 0.90-1.78), maternal transfusion (RR 1.05, 95% CI 0.27-4.09), or time for delivery of placenta (mean difference -1.56 minutes, 95% CI, -9.25-6.13). Three trials comparing prostaglandins with oxytocin agonists, ergometrine, and manual removal reported similar results. CONCLUSIONS: Prostaglandin analogues do not offer an effective alternative for management of retained placenta.

Perioperative events in children with pulmonary hypertension undergoing non-cardiac procedures.

Prior limited research indicates that children with pulmonary hypertension (PH) have higher rates of adverse perioperative outcomes when undergoing non-cardiac procedures and cardiac catheterizations. We examined a single-center retrospective cohort of children with active or pharmacologically controlled PH who underwent cardiac catheterization or non-cardiac surgery during 2006-2014. Preoperative characteristics and perioperative courses were examined to determine relationships between the severity or etiology of PH, type of procedure, and occurrence of major and minor events. We identified 77 patients who underwent 148 procedures at a median age of six months. The most common PH etiologies were bronchopulmonary dysplasia (46.7%), congenital heart disease (29.9%), and congenital diaphragmatic hernia (14.3%). Cardiac catheterizations (39.2%), and abdominal (29.1%) and central venous access (8.9%) were the most common procedures. Major events included failed planned extubation (5.6%), postoperative cardiac arrest (4.7%), induction or intraoperative cardiac arrest (2%), and postoperative death (1.4%). Major events were more frequent in patients with severe baseline PH ( P = 0.006) and the incidence was associated with procedure type ( P = 0.05). Preoperative inhaled nitric oxide and prostacyclin analog therapies were associated with decreased incidence of minor events (odds ratio [OR] = 0.32, P = 0.046 and OR = 0.24, P = 0.008, respectively), but no change in the incidence of major events. PH etiology was not associated with events ( P = 0.24). Children with PH have increased risk of perioperative complications; cardiac arrest and death occur more frequently in patients with severe PH and those undergoing thoracic procedures. Risk may be modified by using preoperative pulmonary vasodilator therapy and lends itself to further prospective studies.

Triple paternal contribution to a normal/complete molar chimeric singleton placenta.

A comprehensive study of unusual cases of placental pathology may provide insight into mechanisms of normal human fertilization and early embryonic development by examining the exception to the rule. A gravida three para two 39-year-old woman was monitored by ultrasound from 16 weeks of gestation for cystic placenta. A female newborn was born at 36 weeks gestation. Pathologic examination of the partially cystic placenta revealed a singleton placenta comprised of 2/3 normal placenta and 1/3 complete hydatidiform mole, largely degenerated. Immunostaining for p57 was negative in stromal cells of the molar villi. Chromogenic in-situ hybridization revealed diploidy in both normal and molar parts. A total of 16 microsatellites were studied by short tandem repeat analysis, 11 of which were informative. The analysis revealed bipaternal molar tissue of dispermic origin. The paternal monospermic contribution to the normal part was different from that in the molar part, thus resulting in tripaternal contribution to the conceptus. A chimera is a single organism composed of two or more different populations of genetically distinct cells that originated from different zygotes (tetragametic) whereas mosaic is a mixture of two cell lines in one organism originating from one zygote. The possible mechanisms leading to the formation of chimeric/mosaic placenta in our case (one of the components being complete hydatidiform mole), including twinning, fusion at an early embryonic stage and diploidization of triploids, are discussed.

Analysis of E2 gene integrity in HPV16 and HPV58 viruses isolated from women with cervical pathology.

Integration of human papillomavirus (HPV) DNA into human cells accompanied by the disruption of the viral genome has been described as a prerequisite for cancer development. This study aimed to investigate E2 gene integrity of HPV16 and HPV58 viruses isolated from infected women with cervical lesions. Forty-two HPV16- and 31 HPV58-positive samples were analysed. E2 integrity was assumed when all fragments covering the E2 gene were amplified with specific polymerase chain reaction primers. Overall, in 59% of the samples, at least one fragment was not amplified in HPV16- (57%) and HPV58-positive samples (61%). Samples from high-grade squamous intraepithelial lesions had the highest frequency of E2 gene disruptions (73%), followed by samples from low-grade squamous intraepithelial lesions (63%) and, finally, samples from invasive cervical cancer (35%). Association between the integrity status of the E2 gene, and lesion grade was assessed by the chi-squared test applied to the combined set of viruses (p = 0.6555) or to populations of the same virus type (HPV58, p = 0.3101; HPV16, p = 0.3024). In conclusion, in this study, no association was found between the presence of E2 gene disruptions and the grade of cervical lesions caused by HPV16 and HPV58.

Serum Adipsin Levels throughout Normal Pregnancy and Preeclampsia.

Adipsin is a protease produced at high levels by adipose tissue. It is involved in complement activation and metabolic control. The objective of this study was to determine the changes in adipsin levels during different stages of normal pregnancy, and its association with obstetric outcomes, such as preeclampsia. This nested case-control study in a longitudinal cohort included normal pregnant (n = 54) and preeclamptic (n = 18) women, both followed throughout pregnancy. Additionally, some of the normal pregnant women were followed up three months postpartum (n = 18). Healthy non-pregnant women were also studied during their menstrual cycle (n = 20). The results of this study show that in healthy non-pregnant women, adipsin levels did not change significantly during the menstrual cycle. In normal pregnant women, adipsin levels were lower (p < 0.01) when compared with non-pregnant healthy women, but these serum levels increased again during postpartum (p < 0.001). Adipsin levels were significantly elevated in preeclamptic women in late pregnancy (P < 0.01). A significant correlation was not found between leptin and adipsin during the three periods of gestation studied in healthy pregnant and preeclamptic women. Our results suggest that adipsin may be involved in pregnancy-associated metabolic changes. Moreover, the increase of adipsin levels towards late gestation in preeclamptic women could be related to the pathophysiology of this disease.

[Anaerobiospirillum thomasii bacteremia with fatal outcome]. / Bacteriemia por Anaerobiospirillum thomasii con desenlace fatal.

Anaerobiospirillum thomasii has been reported as a causative agent of diarrhea in humans; however no bacteremia associated with this pathogen has been described so far. We present here the first case of fatal A. thomasii bacteremia in an alcoholic patient.

Características operativas del diagnóstico clínico con y sin pruebas de consultorio (ph y pruebas de aminas) para el diagnóstico de vaginosis bacteriana, en pacientes sintomáticas en Bogotá, Colombia / Operational characteristics of the clinical diagnosis in the office, with and without tests (pH and amine test), for diagnosing bacterial vaginosis in symptomatic patients in Bogotá, Colombia

Evaluar las características operativas del diagnóstico clínico (síntomas y signos) solo y con pruebas de diagnóstico en el consultorio (pH y prueba de aminas), teniendo como patrón de oro el puntaje de Nugent, para el diagnóstico de vaginosis bacteriana.Materiales y métodos: estudio de validez diagnóstica, ensamblado en un estudio de corte transversal en pacientes con síntomas de infección del tracto genital inferior, quienes consultaron a tres centros de Bogotá en 2010. Se calculó un tamaño de muestra de 1400 participantes. Se realizó un muestreo secuencial. Se tomaron muestras de la pared vaginal para medición de pH, prueba de aminas y tinción de Gram para puntaje de para puntaje de Nugent, considerado como patrón de oro de la entidad. Las bacteriólogas estaban enmascaradas con respecto al diagnóstico clínico y a las pruebas de consultorio. Se midieron la sensibilidad y especificidad, razón de probabilidades RP (+) y RP (-). Se presentan como proporciones con su respectivo intervalo de confianza del 95%.Resultados: la prevalencia de VB fue de 39.6 %, las características operativas de las pruebas con sus respectivos IC 95 %, con el puntaje de Nugent como patrón de oro, fueron: diagnóstico clínico, sensibilidad 75 % (71-78), especificidad 54 % (51-57), pH≥ 5 sensibilidad 99,3 % (98,2-99.8), especificidad 0,57 % (0,2-1,3); prueba de aminas, sensibilidad 99,3 % (98,2-99,8 %), especificidad 99,8 % (99,2-100 %); diagnóstico clínico, más prueba de aminas,más pH ≥ 5,0, sensibilidad 74 % (71-78), especificidad 100 % (99-100).Conclusiones: el diagnóstico clínico es una estrategia sensible para el diagnóstico de VB; la especificidad mejora cuando se combina con la prueba de aminas y el pH vaginal. La prueba de aminas presentó excelente sensibilidad y especificidad, y es útil para mejorar el diagnóstico de VB...

To assess the operational characteristics of the clinical diagnosis (signs and symptoms) alone and with diagnostic tests in the office (pH and amine test), using the Nugent score as the gold standard for diagnosing bacterial vaginosis.Materials and methods: Diagnostic validity study assembled in a cross sectional study in patients with symptoms of lower genitourinary tract infection seen in 3 centres in Bogota in 2010. The calculated sample size was 1400 participants, and a sequential sampling was used. Samples were taken from the vaginal wall for pH measurement, amine test and Gram staining in order to derive the Nugent score, considered the gold standard in this disease. The lab technicians were blinded to the clinical diagnosis and to the office tests. Sensitivity, specificity ad odds ratio OR (+) and OR (-) were measured, and they are presented as proportions with their respective 95% confidence intervals.Results: The prevalence of bacterial vaginosis was 39.6 %, and the operational characteristics of the tests with their respective 95 % CI were as follows: sensitivity and specificity of the clinical diagnosis were 75 % (71-78) and 54 % (51-57), respectively; sensitivity and specificity of pH ≥ 5 were 99.3 % (98.2-99.8), and 0.57 % (0.2-1.3); amine test sensitivity 99.3 % (98.2-99.8 %) and specificity 99.8 % (99.2-100 %); clinical diagnosis plus amine test and pH ≥ 5.0, sensitivity 74 % (71-78), specificity 100 % (99-100).Conclusions: Clinical diagnosis showed a good sensitivity for diagnosing strategy for diagnosing bacterial vaginosis; specificity is improved when clinical findings are combined with amine test and vaginal pH. The amine test was shown to have excellent sensitivity and specificity, and it is useful to improve the diagnosis of bacterial vaginosis...

Bacteriemia por Anaerobiospirillum thomasii con desenlace fatal / Anaerobiopirillum thomasii bacteremia with gatal outcome

Anaerobiospirillum thomasii ha sido descrito como causante de diarrea en humanos, pero no se han informado bacteriemias asociadas a este organismo. En esta comunicación describimos el primer aislamiento de A. thomasii como causa de bacteriemia fatal en una paciente alcohólica

Anaerobiospirillum thomasii has been reported as a causative agent of diarrhea in humans; however no bacteremia associated with this pathogen has been described so far. We present here the first case of fatal A. thomasii bacteremia in an alcoholic patient

Maternal Serum Meteorin Levels and the Risk of Preeclampsia.

BACKGROUND: Meteorin (METRN) is a recently described neutrophic factor with angiogenic properties. This is a nested case-control study in a longitudinal cohort study that describes the serum profile of METRN during different periods of gestation in healthy and preeclamptic pregnant women. Moreover, we explore the possible application of METRN as a biomarker. METHODS AND FINDINGS: Serum METRN was measured by ELISA in a longitudinal prospective cohort study in 37 healthy pregnant women, 16 mild preeclamptic women, and 20 healthy non-pregnant women during the menstrual cycle with the aim of assessing serum METRN levels and its correlations with other metabolic parameters. Immunostaining for METRN protein was performed in placenta. A multivariate logistic regression model was proposed and a classifier model was formulated for predicting preeclampsia in early and middle pregnancy. The performance in classification was evaluated using measures such as sensitivity, specificity, and the receiver operating characteristic (ROC) curve. In healthy pregnant women, serum METRN levels were significantly elevated in early pregnancy compared to middle and late pregnancy. METRN levels are significantly lower only in early pregnancy in preeclamptic women when compared to healthy pregnant women. Decision trees that did not include METRN levels in the first trimester had a reduced sensitivity of 56% in the detection of preeclamptic women, compared to a sensitivity of 69% when METRN was included. CONCLUSIONS: The joint measurements of circulating METRN levels in the first trimester and systolic blood pressure and weight in the second trimester significantly increase the probabilities of predicting preeclampsia.

Spectroscopic determination of relative Brønsted acidity as a predictor of reactivity in aprotic ionic liquids.

A simple titration technique utilizing pyridine as a FTIR spectroscopy probe is demonstrated to successfully predict relative Brønsted acid-limited reaction rates in different ionic liquid (IL) environments. Relative acidity is shown to vary across three aprotic ILs in a manner that is specific to the particular acid-IL pairing.

Imiquimod for anogenital warts in non-immunocompromised adults.

BACKGROUND: 30% of people with anogenital warts (AGW) have spontaneous regression of lesions but there is no way to determine whether a specific lesion will remain. There are a wide range of options available for treating people with AGW and selection is based on clinician's experience, patient preferences and adverse effects. The imiquimod could offer the advantages of patient-applied therapies without incurring the limitations of provider-administered treatments. OBJECTIVES: To assess the effectiveness and safety of imiquimod for the treatment of AGW in non-immunocompromised adults. SEARCH METHODS: We searched the Cochrane Sexually Transmitted Infections Group Specialized Register (15 April 2014), CENTRAL (1991 to 15 April 2014), MEDLINE (1946 to 15 April 2014), EMBASE (1947 to 15 April 2014), LILACS (1982 to 15 April 2014), World Health Organization International Clinical Trials Registry (ICTRP) (15 April 2014), ClinicalTrials.gov (15 April 2014), Web of Science (2001 to 15 April 2014) and OpenGrey (15 April 2014). We also handsearched conference proceedings, contacted trial authors and reviewed the reference lists of retrieved studies. SELECTION CRITERIA: Randomized controlled trials (RCTs) comparing the use of imiquimod with placebo, any other patient-applied or any other provider-administered treatment (excluding interferon and 5-fluorouracil which are assessed in other Cochrane Reviews) for the treatment of AGW in non-immunocompromised adults. DATA COLLECTION AND ANALYSIS: Three review authors independently assessed trials for inclusion, extracted data and assessed risk of bias. We resolved any disagreements through consensus. The quality of the evidence was assessed using the GRADE approach. MAIN RESULTS: Ten RCTs (1734 participants) met our inclusion criteria of which six were funded by industry. We judged the risk of bias of the included trials as high. Six trials (1294 participants) compared the use of imiquimod versus placebo. There was very low quality evidence that imiquimod was superior to placebo in achieving complete and partial regression (RR 4.03, 95% CI 2.03 to 7.99; RR 2.56, 95% CI 2.05 to 3.20, respectively). When compared with placebo, the effects of imiquimod on recurrence (RR 2.76, 95% CI 0.70 to 10.91), appearance of new warts (RR 0.76, 95% CI 0.58 to 1.00) and frequency of systemic adverse reactions (RR 0.91, 95% CI 0.63 to 1.32) were imprecise. We downgraded the quality of evidence to low or very low. There was low quality evidence that imiquimod led to more local adverse reactions (RR 1.73, 95% CI 1.18 to 2.53) and pain (RR 11.84, 95% CI 3.36 to 41.63).Two trials (105 participants) compared the use of imiquimod versus any other patient-applied treatment (podophyllotoxin and podophyllin). The estimated effects of imiquimod on complete regression (RR 1.09, 95% CI 0.80 to 1.48), partial regression (RR 0.77, 95% CI 0.40 to 1.47), recurrence (RR 0.49, 95% CI 0.21 to 1.11) or the presence of local adverse reactions (RR 1.24, 95% CI 1.00 to 1.54) were imprecise (very low quality evidence). There was low quality evidence that systemic adverse reactions were less frequent with imiquimod (RR 0.30, 95% CI 0.09 to 0.98).Finally, two trials (335 participants) compared imiquimod with any other provider-administered treatment (ablative methods and cryotherapy). There was very low quality of evidence that imiquimod did not have a lower frequency of complete regression (RR 0.84, 95% CI 0.56 to 1.28). There was very low quality evidence that imiquimod led to a lower rate of recurrence during six-month follow-up (RR 0.24, 95% CI 0.10 to 0.56) but this did not translate in to a lower recurrence from six to 12 months (RR 0.71, 95% CI 0.40 to 1.25; very low quality evidence). There was very low quality evidence that imiquimod was associated with less pain (RR 0.30, 95% CI 0.17 to 0.54) and fewer local reactions (RR 0.55, 95% CI 0.40 to 0.74). AUTHORS' CONCLUSIONS: The benefits and harms of imiquimod compared with placebo should be regarded with caution due to the risk of bias, imprecision and inconsistency for many of the outcomes we assessed in this Cochrane Review. The evidence for many of the outcomes that show imiquimod and patient-applied treatment (podophyllotoxin or podophyllin) confer similar benefits but fewer systematic reactions with the Imiquimod, is of low or very low quality. The quality of evidence for the outcomes assessing imiquimod and other provider-administered treatment were of very low quality.

Ex vivo endothelin dependent contraction of the remodeled rat spiral artery.

INTRODUCTION: Similarities of the rat to the human placenta make rat pregnancy models relevant to the study of human gestational diseases. Understanding of species differences is necessary to extrapolate from animal models to humans. We observed alpha-smooth muscle actin (αSMA) expression in rat endovascular trophoblasts (EVasT) and investigated the spatial and temporal expression of smooth muscle (SM) proteins and their potential function in remodeled spiral artery. METHODS: Rat placentas were examined from gestational day 13 to term, and were immunostained for cytokeratin, αSMA, alpha heavy chain of SM myosin, non-muscle myosin, Rho proteins, regulators of SM gene expression, myocardin, an early marker of SM differentiation and endothelin receptors A and B (ETA, ETB). Transmission electron microscopy (TEM) was performed. Modified spiral artery rings were studied ex vivo for endothelin-1- induced contraction. RESULTS: EVasT expressed SM proteins co-localizing with cytokeratin confirming their trophoblastic origin from gestational day 13 to term. Thin fibers, consistent with actin fibers, were observed by TEM, in the cellular localization of αSMA in EVasT. Functional experiments revealed that addition of 10(-7) M endothelin-1 ex vivo reduced vascular lumen area by 11.1% ± 1.8% compared with control. This effect was reduced to only 1.0 ± 1.7% with ETA antagonist, and to 5.4 ± 1.7% contraction by ETB antagonist, p < 0.002, for all. DISCUSSION: The expression of SM proteins in EVasT along with the contractibility of the rat remodeled spiral artery ex vivo, suggest that some vascular tone is potentially maintained by endothelin-1, and may play a role in situations of dysregulation of the vasoactive systems.