Guillotine Transmetatarsal Amputations With Staged Closure Promote Early Ambulation and Limb Salvage in Patients With Advanced Chronic Limb-Threatening Ischemia

PURPOSE

Transmetatarsal amputation (TMA) with primary closure has long been an option for limb salvage in patients with advanced chronic limb-threatening ischemia (CLTI) with extensive tissue loss of the forefoot. However, TMA healing and closure techniques are challenging, specifically in high-risk patients. Guillotine transmetatarsal amputations (gTMA) with staged closure may provide an alternative treatment in this population. We report long-term outcomes of such technique.

MATERIALS AND METHODS

A single-center retrospective cohort study of CLTI patients undergoing gTMA between 2017 and 2020 was performed. Limb salvage, wound healing, and survival rates were quantified using Kaplan-Meier (KM) analysis. Multivariate regression was used to identify the effect of patient characteristics on the outcomes.

RESULTS

Forty-four gTMA procedures were reviewed. Median follow-up was 381 (interquartile range [IQR], 212-539.75) days. After gTMA, 87.8% (n=36) of the patients were able to ambulate after a median interval of 2 (IQR, 1-3) days. Eventual coverage was achieved in a personalized and staged approach by using a combination of skin substitutes (88.6%, n=39) ± split thickness skin grafts (STSG, 61.4%, n=27). KM estimates for limb salvage, wound healing, and survival were 84.1%, 54.5%, and 88.6% at 1 year and 81.8%, 63.8%, and 84.1% at 2 years. Wound healing was significantly associated with STSG application (p=0.002, OR=16.5, 95% CI 2.87-94.81).

CONCLUSION

gTMA resulted in high limb salvage rates during long-term follow-up in CLTI patients. Adjunctive STSG placement may enhance wound healing at the gTMA site, thus leading to expedited wound closure. Surgeons may consider gTMA as an alternative to reduce limb loss in CLTI patients at high risk of major amputation.

CLINICAL IMPACT

Currently, the clinical presentation of CLTI is becoming more complex to deal with due to the increasing comorbidities as the society becomes older. The data shown in this article means for clinicians that when facing diffused forefoot gangrene and extensive tissue loss, limb preservation could still be considered instead of major amputation. Guillotine transmetatarsal amputations in the setting of an aggressive multidisciplinary group, can be healed by the responsibly utilization of dermal substitutes and skin grafts leading to the preservation of the extremity, allowing mobility, avoiding of sarcopenia, and decreasing frailty. This will equate to maintenance of independent living and preservation of lifespan.

Development of a single-visit protocol for the management of pregnancy of unknown location following in vitro fertilization: a retrospective study

STUDY QUESTION

Can women with pregnancy of unknown location (PUL) following in vitro fertilization (IVF) be risk-stratified regarding the subsequent need for medical intervention, based on their demographic characteristics and the results of serum biochemistry at the initial visit?

SUMMARY ANSWER

The ratio of serum hCG to number of days from conception (hCG/C) or the initial serum hCG level at ≥5 weeks' gestation could be used to estimate the risk of women presenting with PUL following IVF and needing medical intervention during their follow-up.

WHAT IS KNOWN ALREADY

In women with uncertain conception dates presenting with PUL, a single serum hCG measurement cannot be used to predict the final pregnancy outcomes, thus, serial levels are mandatory to establish a correct diagnosis. Serum progesterone levels can help to risk-stratify women at their initial visit but are not accurate in those taking progesterone supplementation, such as women pregnant following IVF.

STUDY DESIGN, SIZE, DURATION

This was a retrospective study carried out at two specialist early pregnancy assessment units between May 2008 and January 2021. A total of 224 women met the criteria for inclusion, but 14 women did not complete the follow-up and were excluded from the study.

PARTICIPANTS/MATERIALS, SETTING, METHODS

We selected women who had an IVF pregnancy and presented with PUL at ≥5 weeks' gestation.

MAIN RESULTS AND THE ROLE OF CHANCE

A total of 30/210 (14.0%, 95% CI 9.9-19.8) women initially diagnosed with PUL required surgical intervention. The hCG/C was significantly higher in the group of women requiring an intervention compared to those who did not (P = 0.003), with an odds ratio of 3.65 (95% CI 1.49-8.89, P = 0.004). A hCG/C <4.0 was associated with a 1.9% risk of intervention, which accounted for 25.7% of the study population. A similar result was obtained by substituting hCG/C <4.0 with an initial hCG level <100 IU/l, which was associated with 2.0% risk of intervention, and accounted for 23.8% of the study population (P > 0.05).

LIMITATIONS, REASONS FOR CAUTION

A limitation of our study is that it is retrospective in nature, and as such, we were reliant on existing data.

WIDER IMPLICATIONS OF THE FINDINGS

A previous study in women with PUL after spontaneous conception found that a 2% intervention rate was considered low enough to eliminate the need for close follow-up and serial blood tests. Using the same 2% cut-off, a quarter of women with PUL after IVF could also avoid attending for further visits and investigations.

STUDY FUNDING/COMPETING INTEREST(S)

No external funding was required for this study. No conflicts of interest are required to be declared.

TRIAL REGISTRATION NUMBER

N/A.

Myonuclear alterations associated with exercise are independent of age in humans

Age-related decline in skeletal muscle structure and function can be mitigated by regular exercise. However, the precise mechanisms that govern this are not fully understood. The nucleus plays an active role in translating forces into biochemical signals (mechanotransduction), with the nuclear lamina protein lamin A regulating nuclear shape, nuclear mechanics and ultimately gene expression. Defective lamin A expression causes muscle pathologies and premature ageing syndromes, but the roles of nuclear structure and function in physiological ageing and in exercise adaptations remain obscure. Here, we isolated single muscle fibres and carried out detailed morphological and functional analyses on myonuclei from young and older exercise-trained individuals. Strikingly, myonuclei from trained individuals were more spherical, less deformable, and contained a thicker nuclear lamina than those from untrained individuals. Complementary to this, exercise resulted in increased levels of lamin A and increased myonuclear stiffness in mice. We conclude that exercise is associated with myonuclear remodelling, independently of age, which may contribute to the preservative effects of exercise on muscle function throughout the lifespan. KEY POINTS: The nucleus plays an active role in translating forces into biochemical signals. Myonuclear aberrations in a group of muscular dystrophies called laminopathies suggest that the shape and mechanical properties of myonuclei are important for maintaining muscle function. Here, striking differences are presented in myonuclear shape and mechanics associated with exercise, in both young and old humans. Myonuclei from trained individuals were more spherical, less deformable and contained a thicker nuclear lamina than untrained individuals. It is concluded that exercise is associated with age-independent myonuclear remodelling, which may help to maintain muscle function throughout the lifespan.

On the survival of the quantum depletion of a condensate after release from a magnetic trap

We present observations of the high momentum tail in expanding Bose–Einstein condensates of metastable Helium atoms released from a harmonic trap. The far-field density profile exhibits features that support identification of the tails of the momentum distribution as originating in the in-situ quantum depletion prior to release. Thus, we corroborate recent observations of slowly-decaying tails in the far-field beyond the thermal component. This observation is in conflict with the hydrodynamic theory, which predicts that the in-situ depletion does not survive when atoms are released from a trap. Indeed, the depleted tails even appear stronger in the far-field than expected before release, and we discuss the challenges of interpreting this in terms of the Tan contact in the trapped gas. In complement to these observations, full quantum simulations of the experiment show that, under the right conditions, the depletion can persist into the far field after expansion. Moreover, the simulations provide mechanisms for survival and for the the large-momentum tails to appear stronger after expansion due to an acceleration of the depleted atoms by the mean-field potential. However, while in qualitative agreement, the final depletion observed in the experiment is much larger than in the simulation.

Trap frequency measurement with a pulsed atom laser

We describe a novel method of single-shot trap frequency measurement for a confined Bose-Einstein Condensate, which uses an atom laser to repeatedly sample the mean velocity of trap oscillations as a function of time. The method is able to determine the trap frequency to an accuracy of 39 ppm (16 mHz) in a single experimental realization, improving on the literature by a factor of three. Further, we show that by employing a reconstructive aliasing approach our method can be applied to trap frequencies more than a factor of 3 greater than the sampling frequency.

Measurement of a helium tune-out frequency: an independent test of quantum electrodynamics

Despite quantum electrodynamics (QED) being one of the most stringently tested theories underpinning modern physics, recent precision atomic spectroscopy measurements have uncovered several small discrepancies between experiment and theory. One particularly powerful experimental observable that tests QED independently of traditional energy level measurements is the "tune-out" frequency, where the dynamic polarizability vanishes and the atom does not interact with applied laser light. In this work, we measure the tune-out frequency for the 2³S₁ state of helium between transitions to the 2³P and 3³P manifolds and compare it with new theoretical QED calculations. The experimentally determined value of 725,736,700(260) megahertz differs from theory [725,736,252(9) megahertz] by 1.7 times the measurement uncertainty and resolves both the QED contributions and retardation corrections.

The significance of low first trimester serum progesterone in ongoing early pregnancies presenting as pregnancies of unknown location

OBJECTIVES

The primary objective of this study was to ascertain whether there is association between low initial serum progesterone, sonographic parameters and clinical outcomes in women presenting with pregnancies of unknown location (PUL), which are found to be ongoing at their follow up scans in the first trimester.

STUDY DESIGN

This was a non-interventional retrospective cohort study of 1056 patients spanning a 14-year period, conducted in the Early Pregnancy Unit (EPU) of an inner-city teaching hospital. Patients who had an ongoing singleton first trimester pregnancy after presenting with PUL were identified and categorised as having low progesterone if it was 32 nmol/l or lower. The crown-rump length (CRL), mean gestational sac diameter (MGSD) and gestational sac volume (GSV) were measured when the embryo was first seen, and the pregnancy outcome recorded.

RESULTS

Pregnancies with low progesterone tended to have smaller gestational sacs (GS) on follow up scan (p = 0.001) and the sac was smaller than expected for a given CRL (p = 0.000). There was no ultrasound parameter that was characteristic of low progesterone. The observation of a smaller than expected MGSD for a given CRL remained even when only pregnancies with normal outcomes were analysed. Clinical outcome data were available for 854 (80.9 %) women. Overall, 81.4 % (n = 34/43) of pregnancies with low progesterone resulted in livebirth, compared to 91.7 % (n = 744/811) livebirths in pregnancies with higher levels (p = 0.0454).

CONCLUSION

Pregnancies with low progesterone tend to have a smaller GS compared to those with a higher progesterone, and the GSs are smaller than expected for a given CRL. The current study shows that women with low progesterone at the start of pregnancy remain at higher risk of miscarriage, even when the pregnancy is initially found to be viable in the first trimester. These pregnancies also tend to be associated with the sonographic finding of a smaller GS than expected for a given gestational age, regardless of eventual outcome.

Direct Measurement of the Forbidden 2^{3}S_{1}→3^{3}S_{1} Atomic Transition in Helium

We present the detection of the highly forbidden 2^{3}S_{1}→3^{3}S_{1} atomic transition in helium, the weakest transition observed in any neutral atom. Our measurements of the transition frequency, upper state lifetime, and transition strength agree well with published theoretical values and can lead to tests of both QED contributions and different QED frameworks. To measure such a weak transition, we develop two methods using ultracold metastable (2^{3}S_{1}) helium atoms: low background direct detection of excited then decayed atoms for sensitive measurement of the transition frequency and lifetime, and a pulsed atom laser heating measurement for determining the transition strength. These methods could possibly be applied to other atoms, providing new tools in the search for ultraweak transitions and precision metrology.

Ultrasound features of immature ovarian teratomas: Case series and review of literature

INTRODUCTION

Immature ovarian teratomas are rare but account for 10-20% of ovarian cancers in women under the age of 20 years. This study aimed to characterise immature ovarian teratomas using grey-scale and Doppler ultrasonography and review the literature to refine the diagnosis of immature ovarian teratomas.

METHODS

Patients with a confirmed histological diagnosis of immature ovarian teratoma from years 2006-2018, who had undergone a transvaginal ultrasound at two large teaching hospitals, were identified. The imaging was retrieved from the centres clinical databases. Ultrasound scans were performed by experienced ultrasound examiners and described according to International Ovarian Tumour Analysis criteria.

RESULTS

Eight patients were identified in total with a mean age of 26 years (range 13-35). Half of the patients had a past history of a mature ovarian teratoma (3 ipsilateral, 1 contralateral). The cysts were generally large (median 115 mm), fast growing unilateral lesions with a single, peripheral predominantly solid component arising from the cyst wall. The solid component was hyperechoic with multiple foci of fibrosis and numerous small cysts. The cystic component typically formed less than 75% of the lesion and the cyst fluid was of low-level echogenicity. Subjective assessment of vascularity of the solid part of the tumours varied between scores of 1 and 2. Tumour markers showed a raised serum a-fetoprotein level in 42% of these patients.

CONCLUSION

Although there were no ultrasound features that were pathognomonic of immature teratoma, the diagnosis should be suspected in a young woman with a large ovarian cyst with a fibrotic, microcystic solid component, particularly if she has a past history of a dermoid cyst.

Venetoclax, bendamustine, and rituximab in patients with relapsed or refractory NHL: a phase Ib dose-finding study

Background

Venetoclax is a selective, potent inhibitor of the anti-apoptotic B-cell leukemia/lymphoma-2 protein approved for treatment of chronic lymphocytic leukemia. We conducted a dose-finding study of venetoclax in combination with bendamustine-rituximab (BR) in patients with relapsed/refractory non-Hodgkin's lymphoma (NHL).

Patients and methods

BR was given for six cycles at standard doses. Intermittent and continuous oral venetoclax administration was explored at 50-1200 mg daily doses. Co-primary objectives included safety, pharmacokinetics (PKs), maximum-tolerated dose (MTD), and recommended phase II dose (RP2D); secondary objective was preliminary efficacy.

Results

Sixty patients were enrolled: 32 with follicular lymphoma, 22 with diffuse large B-cell lymphoma, and 6 with marginal zone lymphoma. Nausea (70%), neutropenia (68%), diarrhea (55%), and thrombocytopenia (52%) were the most frequent adverse events (AEs). Most common grade 3/4 AEs were neutropenia (60%) and lymphopenia (38%). Serious AEs were reported in 24 patients; the most frequent were febrile neutropenia and disease progression (8% each). Five patients died from either disease progression (n = 4) or respiratory failure (n = 1). MTD was not reached; RP2D for venetoclax-BR combination was established as 800 mg daily continuously. Venetoclax PK exposure with and without BR was comparable. For all patients, overall response rate was 65%. Median duration of overall response, overall survival, and progression-free survival was 38.3 months [95% confidence interval (CI) 10.4-NR], not yet reached, and 10.7 months (95% CI 4.3-21.0), respectively.

Conclusions

This study established the safety profile of venetoclax in combination with BR, and results demonstrated tolerability and preliminary efficacy of the combination. Additional follow-up is needed to better determine the future role of BR plus venetoclax in the treatment of relapsed/refractory B-cell NHL.

Trial registered

Clinicaltrials.gov, NCT01594229.

Differential Effects of Nano TiO₂ and CeO₂ on Normal Human Lung Epithelial Cells In Vitro

Nano-TiO₂ and nano-CeO₂ are among the most widely used engineered nanoparticles (NPs). We investigated a variety of endpoints to assess the toxicity of eight of these NPs to induce potentially adverse health effects in an In Vitro human respiratory epithelial cell model. These endpoints include cytotoxicity, reactive oxygen species (ROS)/reactive nitrogen species (RNS) production, 8-hydroxy-2_-deoxyguanosine (8-oxo-dG), endogenous DNA adducts, Apurinic/apyrimidinic (AP) sites, 4-Hrdoxynonenal (4-HNE) protein adducts, Malondialdehyde (MDA) protein adducts, and genomics analysis on altered signaling pathways. Our results indicated that cytotoxicity assays are relatively insensitive, and we detected changes in other endpoints at concentrations much lower than those inducing cytotoxicity. Among the ROS-related endpoints, 8-oxo-dG is relatively more sensitive than other assays, and nano-TiO₂ induced more 8-oxo-dG formation than nano-CeO₂. Finally, there are many signaling pathways changes at concentrations at which no cytotoxicity was observed. These alterations in signaling pathways correlated well with In Vitro toxicity that was observed at higher concentrations, and with in vivo adverse outcome pathways caused by nano-TiO₂ and nano-CeO₂ in experimental animals.

Noradrenergic depletion causes sex specific alterations in the endocannabinoid system in the Murine prefrontal cortex

Brain endocannabinoids (eCB), acting primarily via the cannabinoid type 1 receptor (CB1r), are involved in the regulation of many physiological processes, including behavioral responses to stress. A significant neural target of eCB action is the stress-responsive norepinephrine (NE) system, whose dysregulation is implicated in myriad psychiatric and neurodegenerative disorders. Using Western blot analysis, the protein expression levels of a key enzyme in the biosynthesis of the eCB 2-arachidonoylglycerol (2-AG), diacylglycerol lipase-α (DGL-α), and two eCB degrading enzymes monoacylglycerol lipase (MGL) and fatty acid amide hydrolase (FAAH) were examined in a mouse model that lacks the NE-synthesizing enzyme, dopamine β-hydroxylase (DβH-knockout, KO) and in rats treated with N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine hydrochloride (DSP-4). In the prefrontal cortex (PFC), DGL-α protein expression was significantly increased in male and female DβH-KO mice (P < 0.05) compared to wild-type (WT) mice. DβH-KO male mice showed significant decreases in FAAH protein expression compared to WT male mice. Consistent with the DβH-KO results, DGL-α protein expression was significantly increased in male DSP-4-treated rats (P < 0.05) when compared to saline-treated controls. MGL and FAAH protein expression levels were significantly increased in male DSP-4 treated rats compared to male saline controls. Finally, we investigated the anatomical distribution of MGL and FAAH in the NE containing axon terminals of the PFC using immunoelectron microscopy. MGL was predominantly within presynaptic terminals while FAAH was localized to postsynaptic sites. These results suggest that the eCB system may be more responsive in males than females under conditions of NE perturbation, thus having potential implications for sex-specific treatment strategies of stress-related psychiatric disorders.

Abstract 5240: Induction of molecular endpoints by reactive oxygen species in human lung cells predicted by physical- chemical properties of engineered nanoparticles

A series of six titanium dioxide and two cerium oxide engineered nanomaterials were assessed for their ability to induce cytotoxicity, reactive oxygen species (ROS), and various types of DNA and protein damage in human respiratory BEAS-2B cells exposed in vitro for 72 hours at several concentrations. Although only limited cytotoxicity was observed at concentrations up to 300 µg/ml for all of the nanomaterials, significant increases in 8-oxo-deoxyguanosine, lipid peroxidation mediated protein adducts, and endogenous DNA adducts measured by 32P-postlabeling were detected at concentrations as low as 30 µg/ml, suggesting that molecular changes associated with ROS induction may provide a better means of assessing the low-dose hazards posed by nanomaterials. To identify molecular properties predictive of the ability of nanoparticles to induce ROS sequelae, a least absolute shrinkage and selection operator multiple regression approach has been used to identify relationships between assay outcomes and nanoparticle physical/chemical properties, including particle size, surface area, zeta potential, and elemental analysis. For several of the assay endpoints examined, concentrations of trace metals in the nanoparticles appear to be better predictors of assay outcomes than physical properties. This is an abstract of a proposed presentation and does not necessarily reflect EPA policy.

Citation Format: Jeffrey A. Ross, Garret B. Nelson, Carlton Jones, Sheau-Fung Thai. Induction of molecular endpoints by reactive oxygen species in human lung cells predicted by physical- chemical properties of engineered nanoparticles [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5240. doi:10.1158/1538-7445.AM2017-5240

Chemical-agnostic hazard prediction: statistical inference of in vitro toxicity pathways from proteomics responses to chemical mixtures

Toxicity pathways have been defined as normal cellular pathways that, when sufficiently perturbed as a consequence of chemical exposure, lead to an adverse outcome. If an exposure alters one or more normal biological pathways to an extent that leads to an adverse toxicity outcome, a significant correlation must exist between the exposure, the extent of pathway alteration, and the degree of adverse outcome. Biological pathways are regulated at multiple levels, including transcriptional, post-transcriptional, post-translational, and targeted degradation, each of which can affect the levels and extents of modification of proteins involved in the pathways. Significant alterations of toxicity pathways resulting from changes in regulation at any of these levels therefore are likely to be detectable as alterations in the proteome. We hypothesize that significant correlations between exposures, adverse outcomes, and changes in the proteome have the potential to identify putative toxicity pathways, facilitating selection of candidate targets for high throughput screening, even in the absence of a priori knowledge of either the specific pathways involved or the specific agents inducing the pathway alterations. We explored this hypothesis in vitro in BEAS-2B human airway epithelial cells exposed to different concentrations of Ni²⁺, Cd²⁺, and Cr⁶⁺, alone and in defined mixtures. Levels and phosphorylation status of a variety of signaling pathway proteins and cytokines were measured after 48 hours exposure, together with cytotoxicity. Least Absolute Shrinkage and Selection Operator (LASSO) multiple regression was used to identify a subset of these proteins that constitute a putative toxicity pathway capable of predicting cytotoxicity. The putative toxicity pathway for cytotoxicity of these metals and metal mixtures identified by LASSO is composed of phospho-RPS6KB1, phospho-p53, cleaved CASP3, phospho-MAPK8, IL-10, and Hif-1α. As this approach does not depend on knowledge of the chemical composition of the mixtures, it may be generally useful for identifying sets of proteins predictive of adverse effects for a variety of mixtures, including complex environmental mixtures of unknown composition.

Single-dose systemic methotrexate vs expectant management for treatment of tubal ectopic pregnancy: a placebo-controlled randomized trial

OBJECTIVE

Methotrexate is used routinely worldwide for the medical treatment of clinically stable women with a tubal ectopic pregnancy. This is despite the lack of robust evidence to show its superior effectiveness over expectant management. The aim of our multicenter randomized controlled trial was to compare success rates of methotrexate against placebo for the conservative treatment of tubal ectopic pregnancy.

METHODS

This study took place in two early-pregnancy units in the UK between August 2005 and June 2014. Inclusion criteria were clinically stable women with a conclusive ultrasound diagnosis of a tubal ectopic pregnancy, presenting with a low serum beta human chorionic gonadotropin (β-hCG) level of < 1500 IU/L. Women were assigned randomly to a single systemic injection of either 50 mg/m² methotrexate or placebo. The primary outcome was a binary indicator for success of conservative management, defined as resolution of clinical symptoms and decline of serum β-hCG to < 20 IU/L or a negative urine pregnancy test without the need for any additional medical intervention. An intention-to-treat analysis was followed.

RESULTS

We recruited a total of 80 women, 42 of whom were assigned to methotrexate and 38 to placebo. The arms of the study were matched in terms of age, ethnicity, obstetric history, pregnancy characteristics and serum levels of β-hCG and progesterone. The rates of success were similar for the two study arms: 83% with methotrexate and 76% with placebo. On univariate analysis, this difference was not statistically significant (χ² (1 degree of freedom) = 0.53; P = 0.47). On multivariate logistic regression, the serum level of β-hCG was the only covariate found to be significantly associated with outcome. The odds of failure increased by 0.15% for each unit increase in β-hCG (odds ratio, 1.0015 (95% CI, 1.0002-1.003); P = 0.02). In 14 women presenting with serum β-hCG of 1000-1500 IU/L, the success rate was 33% in those managed expectantly compared with 62% in those receiving methotrexate. This difference was not statistically significant and a larger sample size would be needed to give sufficient power to detect a difference in the subgroup of women with higher β-hCG. In women with successful conservative treatment, there was no significant difference in median β-hCG resolution times between study arms (17.5 (interquartile range (IQR), 14-28.0) days (n = 30) in the methotrexate group vs 14 (IQR, 7-29.5) days (n = 25) in the placebo group; P = 0.73).

CONCLUSIONS

The results of our study do not support the routine use of methotrexate for the treatment of clinically stable women diagnosed with tubal ectopic pregnancy presenting with low serum β-hCG (< 1500 IU/L). Further work is required to identify a subgroup of women with tubal ectopic pregnancy and β-hCG ≥ 1500 IU/L in whom methotrexate may offer a safe and cost-effective alternative to surgery. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd. Comparación entre una sola dosis de metotrexate sistémico y la conducta expectante en el tratamiento de casos de embarazo ectópico tubárico: un ensayo aleatorio controlado con placebo RESUMEN OBJETIVO: El metotrexate se utiliza de modo rutinario en todo el mundo para el tratamiento de las mujeres clínicamente estables con un embarazo ectópico tubárico. Esto sucede a pesar de la falta de evidencia rigurosa que demuestre que su eficacia es superior a la conducta expectante. El objetivo de este ensayo controlado aleatorio multicéntrico fue comparar las tasas de éxito del metotrexate con las de un placebo para el tratamiento cauteloso del embarazo ectópico tubárico. MÉTODOS: Este estudio se llevó a cabo en dos clínicas de control de gestación temprana en el Reino Unido entre agosto de 2005 y junio de 2014. Los criterios de inclusión fueron mujeres clínicamente estables con un diagnóstico ecográfico concluyente de embarazo ectópico tubárico, las cuáles presentaban una concentración sérica baja de la β hormona coriónica gonadotrópica (β-hCG) inferior a 1500 UI/L. Las mujeres fueron asignadas aleatoriamente a una sola inyección sistémica de 50 mg/m2 de metotrexate o a placebo. El resultado primario fue un indicador binario del éxito del tratamiento conservador, definido como la resolución de los síntomas clínicos y la disminución en el suero de la β-hCG a <20 UI/L o una prueba de embarazo negativa en orina sin la necesidad de ninguna intervención médica adicional. Se hizo un análisis por intención de tratar.

RESULTADOS

Se reclutó un total de 80 mujeres; a 42 de ellas se les asignó el metotrexate y a 38 el placebo. Los grupos del estudio se realizaron en función de la edad, el origen étnico, los antecedentes obstétricos, las características del embarazo y los niveles séricos de la β-hCG y la progesterona. Las tasas de éxito fueron similares para los dos grupos de estudio: 83% con metotrexate y 76% con placebo. En el análisis univariante, esta diferencia no fue estadísticamente significativa (χ2 (1 grado de libertad) = 0,53; P = 0,47). En la regresión logística multivariante, el nivel sérico de la β-hCG fue la única covariable que se encontró significativamente asociada con el resultado. Las probabilidades de fracaso aumentaron en un 0,15% por cada unidad de aumento de la β-hCG (cociente de probabilidad 1,0015 (IC 95%, 1,0002-1,003); P = 0,02). La tasa de éxito en las 14 mujeres con un nivel sérico de la β-hCG de 1000-1500 UI/L fue del 33% en las tratadas con conducta expectante frente al 62% en las que recibieron metotrexate. Esta diferencia no fue estadísticamente significativa, por lo que se necesitaría un tamaño de muestra mayor, lo suficiente como para poder detectar diferencias en el subgrupo de mujeres con una β-hCG más elevada. En las mujeres en las que el tratamiento conservador tuvo éxito, no hubo una diferencia significativa en la mediana de los tiempos de resolución de la ß-hCG entre los grupos del estudio (17,5 (amplitud intercuartílica (IQR), 14-28,0) días (n = 30) en el grupo de metotrexate frente a 14 (IQR, 7-29.5) días (n = 25) en el grupo de placebo; P = 0,73).

CONCLUSIONES

Los resultados de este estudio no apoyan el uso rutinario de metotrexate para el tratamiento de las mujeres clínicamente estables diagnosticadas con un embarazo ectópico tubárico que presenta un nivel sérico bajo la β-hCG (<1500 UI/L). Serán necesarios estudios adicionales para identificar un subgrupo de mujeres con embarazo ectópico tubárico y β-hCG ≥1500 UI/L para quienes el metotrexate puede ofrecer una alternativa segura y rentable en comparación con la cirugía. : : ,,。。 : 2005820146,2。,,β(beta human chorionic gonadotropin,β-hCG)<1500 IU/L。,(50 mg/m² )。,β-hCG<20 IU/L,。。 : 80,42,38。2、、、β-hCG。2:83%,76%。,[χ² (1)=0.53;P=0.47]。logistic,β-hCG。β-hCG,0.15%[,1.0015(95% CI,1.0002~1.003);P=0.02]。14β-hCG1000~1500 IU/L,33%,62%。,β-hCG。,2β-hCG(P=0.73),17.5[(interquartile range,IQR),14~28.0](n=30),14 (IQR,7~29.5)(n=25)。 : 、、β-hCG(<1500 IU/L)。,β-hCG>1500 IU/L、。.

DNA adducts induced by in vitro activation of extracts of diesel and biodiesel exhaust particles

CONTEXT

Biodiesel and biodiesel-blend fuels offer a renewable alternative to petroleum diesel, but few data are available concerning the carcinogenic potential of biodiesel exhausts.

OBJECTIVES

We compared the formation of covalent DNA adducts by the in vitro metabolic activation of organic extracts of diesel-exhaust particles (DEP) from petroleum diesel and soy biodiesel and correlated DNA adduct levels and mutagenicity in Salmonella TA100.

METHODS

We examined two different DEP from petroleum diesel (C-DEP and B0), one from soy bean oil biodiesel (B100) and one from combustion of a blend of 20% B100 and 80% B0 (B20) for in vitro DNA adduct-forming potential under oxidative or nitroreductive conditions in the presence of calf thymus DNA as well as in vivo in Salmonella TA100. The modified DNA was hydrolyzed and analyzed by (32)P-postlabeling using either butanol extraction or nuclease P1 pre-enrichment.

RESULTS

Multiple DNA adducts were produced with chromatographic mobilities consistent with PAH and nitro-PAH adducts. The types and quantities of DNA adducts produced by the two independent petroleum diesel DEP were similar, with both polycyclic aromatic hydrocarbon (PAH)- and nitro-PAH-derived adducts formed. Relative potencies for S9-mediated DNA adduct formation, either per mass of particulate or per MJ(th) energy consumed were B100 > B0 > B20.

CONCLUSIONS

Soy biodiesel emissions induced DNA damage in the form of presumptive PAH and nitro-PAH DNA adducts that correlated with mutagenicity in Salmonella. B20 is the soy biodiesel used most commonly in the US, and it produced the lowest DNA adduct-emission factor, ∼50% that of petroleum diesel.

Abstract 2814: Comparative DNA damage and transcriptomic effects of engineered nanoparticles in human lung cells in vitro

A series of six titanium dioxide and two cerium oxide engineered nanomaterials were assessed for their ability to induce cytotoxicity, reactive oxygen species (ROS), various types of DNA damage, and transcriptional changes in human respiratory BEAS-2B cells exposed in vitro at several concentrations for 72 hours. Only limited cytotoxicity was observed at concentrations up to 300 μg/ml for all of the nanomaterials. Small increases in 8-oxo-deoxyguanosine were induced by some of the nanomaterials, but did not achieve statistical significance. No increases in ethenoadenosine or ethenocytidine were detected by ELISA assays for any of the tested nanomaterials. Several of the nanomaterials exhibited concentration related increases in levels of apurinic/apyrimidinic sites, endogenous DNA adducts measured by 32P-postlabeling, lipid peroxidation, and ROS. Consistent with these findings, several of the nanomaterials also affected expression of genes involved in p53, ATM, and mismatch repair pathways. Integrin signaling pathways were also altered by a majority of the nanomaterials tested. There was general agreement between activity in DNA damage assays and extent of pathway transcriptional alteration. One out of the cerium oxide nanomaterials tested did not induce a high enough incidence of differentially expressed genes relative to controls to allow analysis at the pathway level, and also elicited the lowest response in multiple DNA damage assays. Taken together, these data are consistent with the contribution of DNA damage induced by reactive oxygen species as mediators of potentially adverse biological effects following exposure to engineered titanium and cerium oxide nanomaterials, and suggests the utility of short term in vitro tests to predict relative potencies of these particles.

This is an abstract of a proposed presentation and does not necessarily reflect EPA policy.

Citation Format: Garret B. Nelson, Sheau-Fung Y. Thai, Carlton P. Jones, Audrey Barbee, Micaela Killius, Jeffrey A. Ross. Comparative DNA damage and transcriptomic effects of engineered nanoparticles in human lung cells in vitro. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2814.

OC-13 - Safe and effective use of direct oral anticoagulants (DOAC) versus conventional anticoagulation for the treatment of cancer-related venous thromboembolism

INTRODUCTION

Cancer is a risk factor for the development of venous thromboembolism (VTE). The standard of care for the treatment of cancer-related VTE is a low molecular weight heparin (LMWH) formulation. The treatment for these events can be painful, lengthy, and expensive. The development of DOAC has created new options for the treatment of VTE. Data from a recent systematic review suggested that the safety and effectiveness of DOAC in patients with cancer is equivalent to that of traditional therapies. If equivalent to LMWH, the use of DOAC in the treatment of cancer-related VTE would reduce the risk of VTE recurrence while giving patients freedom from subcutaneous injections.

AIM

Our primary aim was to determine the rate of VTE recurrence in patients on anticoagulation. Secondary aims were determination of the rate of anticoagulant-associated clinically relevant bleeding and VTE recurrence-free survival.

MATERIALS AND METHODS

We performed retrospective analysis (2014-2015) of the electronic medical records (EMR) of adult patients with cancer-related VTE treated with anticoagulation. We selected 122 patients for our final analysis according to the inclusion criteria. Demographic, laboratory, cancer diagnosis, and VTE diagnosis data were collected. We documented VTE recurrence as well as clinically relevant bleeding. Non-parametric statistical procedures were used to determine differences in variables associated with this study among the anticoagulant class groups, with a test significance level of 0.05.

RESULTS

Among 122 patients, 89 (73%) were treated with LMWH, 26 (21%) were treated with DOAC, and 7 (6%) were treated with warfarin. The majority of VTE occurred in patients with advanced disease. The most common index event was pulmonary embolism (49%) followed by catheter-associated deep venous thrombosis (DVT) (24%). Recurrence of VTE occurred in 7.7% of patients receiving DOAC and 7.9% of patients receiving LMWH (P=NS). Major bleeding occurred more often with the use of DOAC (11.5%) than with LMWH (10.1%), but non-major bleeding was more common in patients receiving LMWH (9.0% versus 7.7%). These differences were not statistically significant. There was no mortality attributed to bleeding complications. The VTE recurrence-free survival rates were not statistically different among LMWH versus DOAC (Figure 1).

CONCLUSIONS

Recurrence of cancer-associated VTE is not uncommon, and the treatment of VTE has significant hemorrhagic risks. Our analysis suggests that there is no significant difference in the rate of VTE recurrence and anticoagulant-related bleeding when using oral DOACs versus LMWH. Further studies are needed to compare the safety and effectiveness of these methods of anticoagulation.