Survey of selected pathogens in free-ranging pinnipeds in Uruguay

Marine mammals, regarded as sentinels of aquatic ecosystem health, are exposed to different pathogens and parasites under natural conditions. We surveyed live South American fur seals Arctocephalus australis and South American sea lions Otaria flavescens in Uruguay for Leptospira spp., canine distemper virus (CDV), Mycobacterium spp., Toxoplasma gondii, and Neospora caninum. Samples were collected from 2007 to 2013. The seroprevalence of Leptospira spp. was 37.6% positive, 50.9% negative, and 11.5% suspect for A. australis (n = 61) while for O. flavescens (n = 12) it was 67% positive, 25% negative, and 8% suspect. CDV RNA was not detected in any of the analyzed samples. Most animals tested seropositive to tuberculosis antigens by WiZo ELISA (A. australis: 29/30; O. flavescens: 20/20); reactivity varied with a novel ELISA test (antigens MPB70, MPB83, ESAT6 and MPB59). Seroprevalence against N. caninum and T. gondii was 6.7 and 13.3% positive for O. flavescens and 0 and 2.2% positive for A. australis respectively. To evaluate possible sources of infection for pinnipeds, wild rats Rattus rattus and semi-feral cats Felis catus were also tested for Leptospira spp. and T. gondii respectively. Water samples tested for Leptospira revealed saprofitic L. bioflexa. Pathogenic Leptospira were detected in the kidneys of 2 rats, and cats tested positive for T. gondii (100%). These results represent a substantial contribution to the study of the health status of wild pinnipeds in Uruguay.

Abstract 347: Comparative activity of MBQ-167 metabolites in metastatic breast cancer

Metastasis continues to be the most difficult phase for cancer treatment due to few targeted therapy options. Therefore, we focus on targeting the Rho GTPases Rac1 and Cdc42, key drivers of the primary steps of metastasis: cell migration and invasion. We developed MBQ-167 as a small molecule dual inhibitor for Rac1 and Cdc42 activation with IC50s of 103 and 78 nM, respectively. In metastatic human breast cancer cells, MBQ-167 inhibits the Rac/Cdc42 downstream effector p21-activated kinase (PAK)/LIM kinase/Cofilin signaling, lamellipodia extension, and thus, cell polarity, and migration. In addition, in metastatic breast cancer cells, MBQ-167 inhibits cell proliferation and cell cycle progression to ultimately induce apoptosis via anoikis. MBQ-167 inhibits tumor growth and metastasis in experimental and spontaneous HER-positive and Triple negative breast cancer (TNBC) mouse models. MBQ-167 has 35% bioavailability and is not toxic in rodent or canine models up to 1000 mg/kg. Therefore, we are further developing MBQ-167 as a lead anti metastatic cancer compound. The objective in this study is to elucidate potential activity of MBQ-167 metabolites. Prior work has identified MBQ-167 metabolites via LC MS/MS from a mammalian liver microsome (rats and human) assay. Four of the MBQ-167 metabolites with the highest MS peak area, were analyzed in metastatic breast cancer cell lines, for cell viability via MTT assays and apoptosis via caspase 3/7 assays. We report that the metabolites M6, M7, M8, and M9 did not inhibit cell viability or induce apoptosis at 250 or 500 nM in HER2-type MDA-MB-435, and TNBC MDA-MB-231 and MDA-MB-468 breast cancer cell lines, compared to MBQ-167. We next analyzed whether these metabolites could inhibit the activation of Rac and Cdc42 by analyzing the phosphorylation status of its downstream effector p-21 activated kinase isoforms 1/2/3 (PAK1/2/3). When MBQ-167 and metabolites at 250nM were incubated for 24h in HER2-type MDA-MB-435 metastatic cancer cells, and the lysates western blotted with antibodies to total PAK1/2/3 or phospho-Pak1/2/3, we found a decrease in the phosphorylation levels of PAK in response to MBQ-167 and metabolite M6. However, since the peak area of M6 in the microsome assay is only 6% compared to MBQ-167, we conclude that MBQ-167 is the major active compound with anti-metastatic cancer properties.

Citation Format: Julia I. Medina, Eliud Hernández, Cornelis Vlaar, Suranganie Dharmawardhane. Comparative activity of MBQ-167 metabolites in metastatic breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 347.

Nanocarriers for Anticancer Drug Targeting: Recent Trends and Challenges

Nanocarriers are nanostructured vehicles employed to deliver anticancer drugs to the targeted tumor sites in the body. Nanocarriers have been successfully employed to circumvent certain limitations of conventional anticancer drug delivery while providing greater bioavailability, prolonged circulation time and higher tumor accumulation for enhanced therapeutic outcomes in cancer treatment. Nanocarriers are also responsive to functionalization to tailor their pharmaco-kinetics and achieve enhanced therapeutic outcomes in cancer therapy. Among organic, inorganic and hybrid type, several nanocarriers have gained approval for use in cancer patients, while many more are under clinical development. For the last two decades, cancer immunotherapy-based advanced targeting approaches such as monoclonal antibodies, antibody drug conjugates and immune checkpoint inhibitors that utilize human immune system functions have vastly developed which furnish better treatment options in several intractable cancers compared with traditional cancer therapies. This review discusses the imperative role of tumor vasculature in passive and active targeting of anticancer drugs using organic and inorganic nanocarriers and the current research efforts underway. The advanced targeting approaches for treatment of various cancers and their most recent clinical development scenario have been comprehensively explored. Further, potential challenges associated with each type of nanocarrier, and their translational obstacles are addressed.

Determination of Hansen solubility parameters for sugarcane oil. Use of ethanol in sugarcane wax refining

Currently, the refining of sugarcane wax is carried out with 95% v/v ethanol as solvent. This process has a high rate of ethanol consumption thus, the main objective of this work was to corroborate the feasibility of 95% v/v ethanol as a solvent in the refining of sugarcane wax. The suitability of its performance over other organic solvents was evaluated through the relative energy difference (RED) determined from Hansen solubility parameters (HSPs) of sugarcane oil, which were calculated using HSPiP software. HSPs turned out to be δD = 16.24 MPa½, δP = 3.21 MPa½ and δH = 10.34 MPa½, similar to those reported for pine resin and castor oil. The best solvent was 1-decanol. 95% v/v ethanol turned out to be a bad solvent. Absolute ethanol had a RED value of 0.993, which made it a better candidate since it could reduce consumption rates, and constituted an eco-friendly solvent produced in Cuba for the refining process.

Nociception induces a differential presynaptic modulation of the synaptic efficacy of nociceptive and proprioceptive joint afferents

A previous study has indicated that during the state of central sensitization induced by the intradermic injection of capsaicin, there is a gradual facilitation of the dorsal horn neuronal responses produced by stimulation of the high-threshold articular afferents that is counteracted by a concurrent increase of descending inhibitory actions. Since these changes occurred without significantly affecting the responses produced by stimulation of the low-threshold articular afferents, it was suggested that the capsaicin-induced descending inhibition included a preferential presynaptic modulation of the synaptic efficacy of the slow conducting nociceptive joint afferents (Ramírez-Morales et al., Exp Brain Res 237:1629-1641, 2019). The present study was aimed to investigate more directly the contribution of presynaptic mechanisms in this descending control. We found that in the barbiturate anesthetized cat, stimulation of the high-threshold myelinated afferents in the posterior articular nerve (PAN) produces primary afferent hyperpolarization (PAH) in the slow conducting (25-35 m/s) and primary afferent depolarization (PAD) in the fast conducting (40-50 m/s) articular fibers. During the state of central sensitization induced by capsaicin, there is a supraspinally mediated shift of the autogenic PAH to PAD that takes place in the slow conducting fibers, basically without affecting the autogenic PAD generated in the fast conducting afferents. It is suggested that the change of presynaptic facilitation to presynaptic inhibition induced by capsaicin on the slow articular afferents is part of an homeostatic process aimed to keep the nociceptive-induced neuronal activity within manageable limits while preserving the proprioceptive information required for proper control of movement.

Simalikalactone D, a Potential Anticancer Compound from Simarouba tulae, an Endemic Plant of Puerto Rico

Species of the genus Simarouba have been studied because of their antimalarial and antileukemic activities. A group of oxygenated terpenes called quassinoids have been isolated from species of the Simarouba genus, and are responsible for its therapeutic properties. We hypothesized that Simarouba tulae, an endemic plant from Puerto Rico, is a natural source rich in quassinoid compounds with anticancer activity. The leaves were processed and extracted with solvents of different polarities. The extracts were screened for their antiproliferative activity, and it was shown that the chloroform extract was the most active extract. This extract was purified using different chromatographic techniques to afford the quassinoid simalikalactone D (SKD). This compound was further characterized using NMR and X-ray diffraction analysis. A reassessment of original structural assignments for SKD is proposed. SKD showed high cytotoxicity activity, with an IC₅₀ of 55, 58, and 65 nM in A2780CP20 (ovarian), MDA-MB-435 (breast), and MDA-MB-231 (breast) cell lines, respectively. Exposure to SKD led to 15% inhibition of the migration of MDA-MB-231 cells.

Post-mortem toxicology in the diagnosis of sudden death in young and middle-aged victims

OBJECTIVE

We aimed to investigate the impact of the toxicological results found in cases of sudden death (SD) and to correlate the clinical, autopsy and genetic findings with the toxicology results.

MATERIALS AND METHODS

Consecutive SD in people aged between 16 and 50 years with medico-legal autopsies and toxicology studies were included over a 3-year period. The comparison between the toxicological data and demographic characteristics, clinical circumstances, autopsy, and genetic results were taken into account.

RESULTS

101 cases were finally included. They were predominately males (84%) and the mean age was 39.8 years. 52 (51.5%) cases had positive toxicological findings and in 25 cases (24.8%), toxic compounds were considered the first cause of death. Ethanol was the most frequently identified agent (69%), following by licit drugs (56%) and drugs of abuse (39%). Cases with positive toxicology were younger than those with negative results (37.9±9.1 vs. 41.9±7.8; p=0.02). Patients with more than 3 comorbidities showed an association with positive toxicological results (n=14 vs. n=3; p=0.017). The genetic study was performed in 70 (69.3%) SD cases. We identified pathogenic or likely pathogenic variants in 17.1% cases and uncertain significance variants in 42.8% cases. 58% of these variants were probably related to the cause of death.

CONCLUSIONS

A large fraction of SD victims had positive toxicological findings and a quarter of deaths were directly caused by toxic substances. The identification of the factors that trigger SD provides a good approach to contribute in avoiding future episodes.

Low-frequency variants at the CYP2C9 locus among Puerto Rican patients on warfarin: in silico predictions of functionality and conservation

Aim: Perform in silico predictions of functional consequences of CYP2C9 variants identified by next-generation sequencing in Puerto Ricans. Methods: Identified low-frequency CYP2C9 variants (minor allele frequencies <2%) were evaluated using the Combined Annotation-Dependent Depletion (CADD v1.3) tools and molecular modeling/docking analysis to predict impact on CYP2C9 activity. Results: CYP2C9*5,*8,*9,*11,*12,*21 and a novel *61 induce conformational changes that affect the binding site of S-warfarin. Most of these deleterious variants occur at higher frequency among individuals with large African ancestry. Conclusion: The unfavorable distance of S-warfarin from heme group, and low-binding interactions due to these CYP2C9 variants, suggest major complications during warfarin therapy. This study contributes to the field by predicting functional alterations of rare CYP2C9 variants for the first time in Hispanics.

Self-referencing mW-scale detection of sub-ns optical phase modulation in acetylene at 1530 nm

Application of the phase memory of acetylene (C₂H₂) vibrational-rotational transitions in the 1520-1540 nm wavelength range for a self-referencing homodyne detection of a sub-nanosecond optical phase modulation is reported. In the proposed configuration the collinearly propagating coherent dipole radiation of the excited molecule acts like a phase-locked reference wave (local oscillator) that enables transformation of the initial phase modulation into the intensity one. This technique does not need high light intensity and can operate in a linear range of the medium optical absorption. The linear optical phase demodulation (i.e., transformation of the phase-to-amplitude light modulation) is interpreted as an introduction of an additional phase shift to the carrier frequency component of the modulated signal in the maximum of the dispersion curve of a narrow optical absorption peak. It has been experimentally demonstrated with the bulk 10 cm long cuvette filled with low pressure (∼2  Torr) acetylene at room temperature. Effective demodulation of the milliwatt-scale incident laser wave of a single- and multi-mode structure is shown. As expected, the response to the fast (<1  ns) phase modulation was quadratic when the acetylene inhomogeneous Doppler-broadened (∼500  MHz) absorption line is excited in its center and was linearized by tuning at one of the absorption line sides. It is of a differentiating (high-pass) type with the cutoff frequency determined by the total spectral width of the utilized absorption line. Expected detection resolution is determined by the photon noise of the incident light intensity.

Synthesis, Anti-Cancer and Anti-Migratory Evaluation of 3,6-Dibromocarbazole and 5-Bromoindole Derivatives

In this study, a new series of N-alkyl-3,6-dibromocarbazole and N-alkyl-5-bromoindole derivatives have been synthesized and evaluated in vitro as anti-cancer and anti-migration agents. Cytotoxic and anti-migratory effects of these compounds were evaluated in MCF-7 and MDA-MB-231 breast cancer cell lines and an insight on the structure-activity relationship was developed. Preliminary investigations of their anti-cancer activity demonstrated that several compounds have moderate antiproliferative effects on cancer cell lines with GI50 values in the range of 4.7-32.2 µM. Moreover, carbazole derivatives 10, 14, 15, 23, and 24 inhibit migration activity of metastatic cell line MDA-MB-231 in the range of 18-20%. The effect of compounds 10, 14, and 15 in extension of invadopodia and filopodia was evaluated by fluorescence microscopy and results demonstrated a reduction in actin-based cell extensions by compounds 10 and 15.

A comparison of sexual competitiveness and demographic traits of Anastrepha obliqua (Macquart) (Diptera: Tephritidae) among fruit-associated populations

The control of Anastrepha obliqua includes the sterilization of mass-reared insects grown in isolation in a constantly controlled environment. Through time, laboratory mass-reared colonies may produce flies with lower field performance. To recover the genetic variation and aptitude of mass-reared populations, wild insects are introduced into mass-reared colonies. Our aim in this study was to determine whether the host species from two localities influence the life history traits of A. obliqua. We collected flies as larvae from infested fruits of Spondias purpurea, S. mombin, Mangifera indica cv. 'piña', and M. indica cv. 'coche' from two localities in Chiapas, Mexico. There were significant differences in the mating competitiveness of males collected from mango cv. 'coche' compared with mass-reared males. There were no differences in the mating propensity between flies from the two localities, even in the number of matings, when weight was considered as a covariable. The mass-reared strain showed the earliest age at first oviposition. The locality affected the longevity and oviposition period, and these influenced the birth rate, intrinsic rate of increase, finite rate of population increase, mean generation time, and doubling time. According to the demographic parameters, the population of S. mombin would allow artificial colonization in less time, considering that it has a high reproduction rate starting at an early age. Even in the propensity test, it had the highest number of matings. However, males with greater sexual competitiveness and longevity for colonization corresponded to those collected from S. purpurea.

Descending inhibition selectively counteracts the capsaicin-induced facilitation of dorsal horn neurons activated by joint nociceptive afferents

Previous studies from our laboratory showed that in the anesthetized cat, the intradermal injection of capsaicin in the hindpaw facilitated the intraspinal field potentials (IFPs) evoked by stimulation of the intermediate and high-threshold myelinated fibers in the posterior articular nerve (PAN). The capsaicin-induced facilitation was significantly reduced 3-4 h after the injection, despite the persistence of hindpaw inflammation. Although this effect was attributed to an incremented descending inhibition acting on the spinal pathways, it was not clear if it was set in operation once the capsaicin-induced effects exceeded a certain threshold, or if it was continuously operating to keep the increased neuronal activation within manageable limits. To evaluate the changes in descending inhibition, we now examined the effects of successive reversible spinal blocks on the amplitude of the PAN IFPs evoked at different times after the intradermal injection of capsaicin. We found that after capsaicin the PAN IFPs recorded in laminae III-V by activation of high-threshold nociceptive Aδ myelinated fibers increased gradually during successive reversible spinal blocks, while the IFPs evoked by intermediate and low threshold proprioceptive Aβ afferents were only slightly affected. It is concluded that during the development of the central sensitization produced by capsaicin, there is a gradual increase of descending inhibition that tends to limit the nociceptive-induced facilitation, mainly by acting on the neuronal populations receiving inputs from the capsaicin-activated afferents without significantly affecting the information on joint angle transmitted by the low threshold afferents.

Abstract 4185: The novel Rac inhibitor HV-107 as a potential therapeutic for metastatic breast cancer

Breast cancer is the first cause of death in women globally. Metastatic breast cancer, which occurs when cancer cells migrate from the primary tumor and establish in distant organs, is estimated to affect more than a quarter of a million of women in the US. Regrettably, metastatic breast cancer still lacks effective treatment and remains the principal cause of breast cancer mortality. Therefore, it is imperative to develop new and more effective strategies to inhibit metastasis. A promising target for anti-metastatic cancer therapy is the Rho GTPase Rac because it plays a key role in the regulation of cellular adhesion, migration, proliferation and survival; processes which promote tumorigenesis and metastasis. Recently, our group developed Ehop-016, a small molecule that inhibits Rac in metastatic breast cancer cells with an IC50 of 1µM and reduces the activity of its downstream effector p21-activated kinase (PAK). Ehop-016 also inhibits tumor growth, angiogenesis, and metastasis in a mouse model of metastatic breast cancer. However, its relative bioavailability is moderate and should be further improved. Therefore, in an effort to find a compound with greater inhibitory capacity and bioavailability, we tested several Ehop-016 derivatives for their activity against Rac and their toxicity towards metastatic breast cancer cells. Using Rac pulldown assays we show that HV-107 at 250nM inhibits Rac activation by 55% in MDA-MB-231 and MDA-MB-435 metastatic breast cancer cells. The effects of HV-107 on cell viability were tested by MTT assays and our results indicate HV-107 at ≥500nM significantly inhibits metastatic breast cancer cell viability, while showing minimal toxicity towards non-cancerous mammary epithelial cells. We also measured caspase 3 activity, in order to evaluate apoptosis as a potential mechanism of HV-107-induced cell death. Our results show HV-107 at 1000nM causes a significant 1.5 fold increase in caspase 3 activity in MDA-MB-231 cells, indicating HV-107 affects cell viability by inducing apoptosis. Finally, we tested HV-107 in a mouse model of metastatic breast cancer and found a 25% reduction in tumor growth in mice treated with 5mg/kg BW HV-107. Taken together, our results suggest HV-107 is approximately four times more efficient than the parent compound Ehop-016 and has potential as anti-breast cancer metastasis therapeutic.

This study was supported by awards from the Susan Komen for the Cure, NIH/NIMHHD U54MD008149, and the Puerto Rico Science and Technology Trust to SD; NIH/NCRR R25GM061838 to UPR MSC; NIH/NIMHHD RCMI 8G12MD007583RCMI, Title V PPOHA 031M10505 and Title V Cooperative P031S130068 from U.S. Department of Education to UCC; and PRINBRE (NIH/NIGMS P20GM103475-13) Sub-Award to LCP.

Citation Format: Grace E. Velez Crespo, Eliud Hernández, Cornelis Vlaar, Suranganie Dharmawardhane, Linette Castillo-Pichardo. The novel Rac inhibitor HV-107 as a potential therapeutic for metastatic breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4185.

Supraspinal modulation of neuronal synchronization by nociceptive stimulation induces an enduring reorganization of dorsal horn neuronal connectivity

KEY POINTS

The state of central sensitization induced by the intradermic injection of capsaicin leads to structured (non-random) changes in functional connectivity between dorsal horn neuronal populations distributed along the spinal lumbar segments in anaesthetized cats. The capsaicin-induced changes in neuronal connectivity and the concurrent increase in secondary hyperalgesia are transiently reversed by the systemic administration of small doses of lidocaine, a clinically effective procedure to treat neuropathic pain. The effects of both capsaicin and lidocaine are greatly attenuated in spinalized preparations, showing that supraspinal influences play a significant role in the shaping of nociceptive-induced changes in dorsal horn functional neuronal connectivity. We conclude that changes in functional connectivity between segmental populations of dorsal horn neurones induced by capsaicin and lidocaine result from a cooperative adaptive interaction between supraspinal and spinal neuronal networks, a process that may have a relevant role in the pathogenesis of chronic pain and analgesia.

ABSTRACT

Despite a profusion of information on the molecular and cellular mechanisms involved in the central sensitization produced by intense nociceptive stimulation, the changes in the patterns of functional connectivity between spinal neurones associated with the development of secondary hyperalgesia and allodynia remain largely unknown. Here we show that the state of central sensitization produced by the intradermal injection of capsaicin is associated with structured transformations in neuronal synchronization that lead to an enduring reorganization of the functional connectivity within a segmentally distributed ensemble of dorsal horn neurones. These changes are transiently reversed by the systemic administration of small doses of lidocaine, a clinically effective procedure to treat neuropathic pain. Lidocaine also reduces the capsaicin-induced facilitation of the spinal responses evoked by weak mechanical stimulation of the skin in the region of secondary but not primary hyperalgesia. The effects of both intradermic capsaicin and systemic lidocaine on the segmental correlation and coherence between ongoing cord dorsum potentials and on the responses evoked by tactile stimulation in the region of secondary hyperalgesia are greatly attenuated in spinalized preparations, showing that supraspinal influences are involved in the reorganization of the nociceptive-induced structured patterns of dorsal horn neuronal connectivity. We conclude that the structured reorganization of the functional connectivity between the dorsal horn neurones induced by capsaicin nociceptive stimulation results from cooperative interactions between supraspinal and spinal networks, a process that may have a relevant role in the shaping of the spinal state in the pathogenesis of chronic pain and analgesia.

Design, synthesis and biological evaluation of new carbazole derivatives as anti-cancer and anti-migratory agents

Based on the efficacy of EHop-016 as an inhibitor of migration and Rac1 activation, a new series of carbazole derivatives has been synthesized. Cytotoxic and anti-migratory effects of these compounds were evaluated in MCF-7 and MDA-MB-231 breast cancer cell lines. Preliminary investigations of their anticancer activity demonstrated that several compounds have moderate antiproliferative effects on cancer cell lines with GI50 values in the range of 13-50 µM. Furthermore, compounds 3b and 11b inhibit migration activity of metastatic cell line MDA-MB-231 by 32% and 34%, respectively. Compound 11b was shown to inhibit activation of the Rho GTPase Rac1 by 55% at 250 nM in both MDA-MB-231 and MDA-MB-435 cell lines. Compared with the IC50 of Rac1 inhibition by lead compound EHop-016 of 1.1 µM, compound 11b demonstrates 4X improved in vitro efficacy.

Abstract 181: Discovery of novel targeted therapeutics for metastatic breast cancer

Metastatic disease is the primary cause of breast cancer mortality, due to the lack of effective therapy. The Rho GTPase Rac is integral for the promotion of cancer cell migration/invasion, proliferation, and survival. Since metastatic breast cancers often overexpress or exhibit high Rac activity, inhibition of Rac is a viable strategy against metastatic cancer. Recently, we characterized EHop-016, a small molecule that inhibits Rac activity of metastatic breast cancer cells with an IC50 of 1 µM. EHop-016 is 10-100 times more active than previously available Rac inhibitors, and is the first compound shown to inhibit the activation of Rac by the oncogenic GEF Vav. EHop-016 inhibits the activity of the Rac downstream effector p21 activated kinase (PAK), lamellipodia extension, and cell migration of metastatic breast cancer cells. We also reported that EHop-016 at ≥ 25 mg/kg Body Weight (BW) significantly reduced tumor growth, metastasis, and angiogenesis in a mouse model. However, our recent pharmacokinetic study of EHop-016 in a mouse model demonstrated that the bioavailability of Ehop-016 needs to be improved for further pharmacological development. Therefore our hypothesis is that improvement of the EHop-016 structure will provide probes with increased potency against Rac and, therefore, increased bioavailability. Herein we have tested several Ehop-016 derivatives for their effects on breast cancer cell viability and Rac activation. Using MTT assays we found that the Ehop-016 derivatives, HV-107 and HV-118, significantly inhibit the viability of metastatic breast cancer cell lines MDA-MB-231 and MDA-MB-435. The effects of HV-107 and HV-118 on the inhibition of Rac activation were tested by ELISA-based Rac activity assays and pulldown assays. Results show that at 250nM, HV-107 inhibits Rac activation by 55%, whereas HV-118 has a similar effect at 100nM in MDA-MB-231 and MDA-MB-435 cells. Taken together, our findings suggest HV-107 and HV-118 as promising Ehop-016 derivatives with potential as anti-metastatic agents, which should be further characterized.

This study was supported by awards from the Susan Komen for the Cure, NIH/NIMHHD U54MD008149, and the Puerto Rico Science and Technology Trust to SD; NIH/NCRR R25GM061838 to UPR MSC; NIH/NIMHHD RCMI 8G12MD007583RCMI, Title V PPOHA 031M10505 and Title V Cooperative P031S130068 from U.S. Department of Education to UCC; and PRINBRE (NIH/NIGMS P20GM103475-13) Pilot Project to LCP.

Citation Format: Cristina Del Valle, Eliud Hernández, Cornelis P. Vlaar, Luis A. Cubano, Suranganie Dharmawardhane, Linette Castillo-Pichardo. Discovery of novel targeted therapeutics for metastatic breast cancer [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 181. doi:10.1158/1538-7445.AM2017-181

Therapy with ombitasvir/paritaprevir/ritonavir plus dasabuvir is effective and safe for the treatment of genotypes 1 and 4 hepatitis C virus (HCV) infection in patients with severe renal impairment: A multicentre experience

Limited data are available on direct-acting antivirals for treating hepatitis C virus (HCV) infection in patients with severe renal impairment. The aim of this study was to evaluate the effectiveness and safety of ombitasvir/paritaprevir/ritonavir (OBV/PTV/r) ± dasabuvir (DSV) ± ribavirin (RBV) in patients with stage 4 or 5 chronic kidney disease (CKD) and HCV genotype 1 or 4 infection in real clinical practice, and to investigate pharmacological interactions. This retrospective study included patients treated with OBV/PTV/r+DSV±RBV or OBV/PTV/r+RBV with CKD stage 4 (eGFR: 15-29 mL/min/1.73m² ) or 5 (eGFR<15 mL/min/1.73m² or requiring dialysis) and HCV infection by genotypes 1 and 4 between April 2015 and October 2015 in nine Spanish centres. Sustained virological response at 12 weeks (SVR12) was assessed, and clinical and laboratory data, fibrosis stage, adverse events and pharmacological interactions were reported. Forty-six patients were included: 10 (21.7%) had CKD stage 4 and 36 (78.2%) CKD stage 5. Seventeen (36.9%) had cirrhosis. SVR12 rate in the intention-to-treat population was 95.7%. Twenty-one (45.6%) received RBV, which was discontinued in two (9.5%) patients. Anaemia (haemoglobin <10 g/dl) occurred in 12 patients (57.1%) with RBV vs 10 (40.0%) without RBV (P=.246). Renal function remained stable during antiviral therapy. Nine patients (19.5%) experienced serious adverse events unrelated to antiviral therapy. Concomitant medication was discontinued or modified in 41.3% of patients. In conclusion, the effectiveness of OBV/PTV/r±DSV±RBV in patients with CKD 4-5 was similar to that observed in those with normal renal function and was not associated with severe adverse events.

Abstract P4-03-16: FAPα (fibroblast activation protein-α) analysis in breast tumor cells and stroma after neoadjuvant treatment

Background: FAPα is a transmembrane serine protease expressed on cancer associated fibroblast that promotes tumour growth and invasion. In patients (pts) with poor outcome and survival FAPα is highly overexpressed. FAPα is also expressed in stroma across all breast cancer subtypes without association with clinicopathological factors. Pts without Complete Pathological Response (pCR) after Neoadjuvant Chemotherapy (NC) had poor outcome. We analysed the relationship between the expression of FAPα in stroma (fibroblast) and in epithelial breast cancer cells of pts without pCR after NC (taxanes, antracyclines and trastuzumab in Her2+).

Methods: 60 pts were included. ER, PR and Ki67 were studied by IHQ (Ventana) and Her2 by FISH (PatnVysion). FAPα expression was determined by IHQ (polyclonal, Ventana). St Gallen guidelines for subtype of breast cancer were used.

Results: 53 pts had tissue. Median age 47 years (range 29-68). Median tumour size 43mm and 10 (18.9%) were multifocal. 37 (69.8%) had positive axillary nodes. 47 were ductal invasive carcinomas. 33 (62.3%) were grade 2 and 20 (37.7%) grade 3. 44 pts (83%) had ER+ (20 luminal B), 17 (32%) Her2+ and 6 (11%) triple negative(TN). Median Ki67 was 22% (p25-75:15-38%). Miller-Payne response was 1.9% G1 (1pt), 43.4% G2 (23 pts), 41.5% G3 (22 pts) and 13.2% G4 (7 pts). The recurrences were 2 local and 12 distant (26.4%). Median FAPα in residual epithelial breast cancer cells after NC was 85% (p25-75:30-95%) and in the stroma 20% (p25-75:10-62%). Median epithelial FAPα was 55% in TN, 85% Her2, 72.5% luminal A and 92.5% in luminal B. Median stromal FAPα was 52.5% in TN, 20% Her2, 15% luminal A and 15% in luminal B. There is not association between stromal FAPα and clinicopathological features, but a higher epithelial FAPα was found in tumours wih higher ER, PR and Ki67. In luminal B subtype, stromal FAPα was smaller in pts with relapses (median 7.5%) than without relapses (median 30%). Conclusions: Stromal FAPα in residual cancer after NC is higher in TN breast cancer but without association with relapses in our small sample. However, in luminal B subtype stromal FAPα is smaller in pts with relapses.

Citation Format: Calvo I, Prieto M, Suárez-Gauthier A, Pérez FJ, Hernández E, Acosta D, Cárdenas JM, López-Ríos F, Estévez LG. FAPα (fibroblast activation protein-α) analysis in breast tumor cells and stroma after neoadjuvant treatment [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P4-03-16.

Treatment of Chronic Lower Extremity Ulcers with A New Er:Yag Laser Technology

Chronic lower extremity ulcers (CLEUs) have a high prevalence and are difficult to treat due to their various aetiologies. The aim of this study is to evaluate the results achieved in treating CLEUs using an Erbium: YAG (Er:YAG) laser with RecoSMA technology. This laser emits thousands of microbeams of energy causing superficial epidermal ablation and a separation of dermal fibres due to a mechanical-acoustic and resonance effect. The evaluation of the results achieved was carried out by questionnaires completed by 18 patients enrolled in the study. Histological studies and photographs taken before each session (16 sessions in total) were analysed to visually monitor the clinical progress. The analyses were carried out with the help of computer software. The results after 16 treatment sessions showed the complete healing of ulcers or a decrease in their initial area of at least 55% in over 65% of the patients treated. The Student's t-test and Fisher's exact test were used for statistical analysis. The Er:YAG laser and RecoSMA technology ablates few epidermal cell layers, producing a mechanical-acoustic effect with resonance action leading to tissue regeneration mechanisms. This technology offers an effective and safe alternative for treating CLEUs.

Comparison of the effects of mesquite pod and Leucaena extracts with phytoestrogens on the reproductive physiology and sexual behavior in the male rat

Mesquite (Prosopis sp.) and Leucaena leucocephala are widespread legumes, widely used to feed several livestock species and as food source for human populations in several countries. Both mesquite and Leucaena contain several phytoestrogens which might have potential estrogenic effects. Thus, the aim of this study was to evaluate the effects of mesquite pod and Leucaena extracts on several aspects of behavior and reproductive physiology of the male rat. The effects of the extracts were compared with those of estradiol (E2) and of two isoflavones: daidzein (DAI) and genistein (GEN). The following treatments were given to groups of intact male rats: vehicle; mesquite pod extract; Leucaena extract; E2; DAI; GEN. The results indicate that mesquite pod and Leucaena extracts disrupt male sexual behavior in a similar way to DAI and GEN, but less than E2. The main disruptor of sexual behavior was E2, however after 40 and 50days of administration, both extracts and phytoestrogens disrupted sexual behavior in a similar way to E2. The extracts also increased testicular germ cell apoptosis, decreased sperm quality, testicular weight, and testosterone levels, as phytoestrogens did, although these effects were less than those caused by estradiol. The number of seminiferous tubules with TUNEL-positive germ cells increased in extracts treated groups in a similar way to phytoestrogens groups, and E2 caused the greatest effect. The number of TUNEL-positive cells per tubule increased only in Leucaena extract and E2 groups, but not in mesquite- and phytoestrogens-treated groups. Spermatocytes and round spermatids were the TUNEL-positive cells observed in all experimental groups. This effect was associated with smaller testicular weights without atrophy in experimental groups compared with control. Testicular atrophy was only observed in estradiol-treated males. Testosterone decreased in males of all experimental groups, compared with control, this androgen was undetectable in E2 treated males. These results suggest that mesquite pod and Leucaena extracts cause effects similar to those of phytoestrogens in male rat reproduction, these effects were lower than those caused by E2.

A master dynamic flow diagram for the shear thickening transition in micellar solutions

The shear thickening behavior of dilute micellar solutions of hexadecyltrimethylammonium-type surfactants with different counterions (tosylate, 3- and 4-fluorobenzoate, vinylbenzoate and salicylate) and of n-alkyltetradecylammonium bromide (CnTAB), with n = 14, 16 and 18, is examined here. These solutions undergo a shear thickening transition due to the formation of shear-induced structures (SISs) in the shear range studied. Here we report a relationship between the shear thickening intensity and the differences in the hydrophobicity of counterions according to the Hofmeister-like anion series, which leads to a master flow diagram. This master flow diagram is produced by plotting a normalized shear thickening intensity (Iη - 1)/(Imax - 1) versus CD/CD,max, where Iη is the shear-thickening intensity, defined as the largest viscosity obtained in the shear-thickening transition (STT) at a given surfactant concentration CD divided by the Newtonian viscosity η0, and Imax is the largest intensity value obtained in the STT at a surfactant concentration CD,max. The master flow diagram is built using several cetyltrimethylammonium-type surfactants with different counterions, according to a Hofmeister-like series, and by n-alkyltetradecylammonium bromide surfactants with different alkyl chain lengths.

[Tibiotalocalcaneal arthrodesis using a humeral locking plate]

OBJECTIVE

To describe the results of tibiotalocalcáneal arthrodesis (TTC) using a humeral locking plate.

METHODS AND MATERIALS

A retrospective, observational study was conducted between January 2007 and December 2013 in the Hospital Militar Central de Bogotá. The study included patients with symptomatic osteoarthritis diagnosed clinically and radiologically, and who underwent TTC arthrodesis using a humeral locking plate with a minimum follow up of 6 months.

RESULTS

The total number patients was 35, of whom 7 (20%) were women and 28 (80%) men, with a mean age 36.3 years (19.77).

AETIOLOGY

74% with post-traumatic arthritis, most of them secondary to gunshot wounds and fragmentation weapons, and neuropathic in 20%. An autogenous graft was used in 13 cases, and 14 cases using both, with a mean consolidation time of 4.37 months. Complications include, delayed union in 3 cases, and surgical site infection in 4. The postoperative functionality (AOFAS) mean was 66.7/100 points, with a score of 2.35 on a visual analogue pain scale.

CONCLUSION

TTC arthrodesis using a humeral locking plate is a suitable option for fixing this type of arthrodesis, with a low rate of complications, and postoperative results that revealed satisfactory improvement in pain and consolidation.

The Orinoco megadelta as a conservation target in the face of the ongoing and future sea level rise

Currently, risk assessments related to rising sea levels and the adoption of defensive or adaptive measures to counter these sea level increases are underway for densely populated deltas where economic losses might be important, especially in the developed world. However, many underpopulated deltas harbouring high biological and cultural diversity are also at risk but will most likely continue to be ignored as conservation targets. In this study, we explore the potential effects of erosion, inundation and salinisation on one of the world's comparatively underpopulated megadeltas, the Orinoco Delta. With a 1 m sea level rise expected to occur by 2100, several models predict a moderate erosion of the delta's shorelines, migration or loss of mangroves, general inundation of the delta with an accompanying submersion of wetlands, and an increase in the distance to which sea water intrudes into streams, resulting in harm to the freshwater biota and resources. The Warao people are the indigenous inhabitants of the Orinoco Delta and currently are subject to various socioeconomic stressors. Changes due to sea level rise will occur extremely rapidly and cause abrupt shifts in the Warao's traditional environments and resources, resulting in migrations and abandonment of their ancestral territories. However, evidence indicates that deltaic aggradation/accretion processes at the Orinoco delta due to allochthonous sediment input and vegetation growth could be elevating the surface of the land, keeping pace with the local sea level rise. Other underpopulated and large deltas of the world also may risk immeasurable biodiversity and cultural losses and should not be forgotten as important conservation targets.

Tourniquet modification of the associating liver partition and portal ligation for staged hepatectomy procedure

BACKGROUND

In staged liver resections, associating liver partition and portal ligation for staged hepatectomy (ALPPS) achieves sufficient hypertrophy of the future liver remnant (FLR) in 7 days. This is based on portal vein ligation and transection, and on occlusion of intrahepatic collaterals. This article presents a new surgical technique for achieving rapid hypertrophy of the FLR, which also involves adding intrahepatic collateral occlusion to portal vein transection.

METHODS

Patients scheduled for two-stage liver resection for primary or secondary liver tumours, in whom the FLR was considered too small, were enrolled prospectively. In the first stage, a tourniquet was placed around the parenchymal transection line, and the right portal vein was ligated and cut (associating liver tourniquet and portal ligation for staged hepatectomy, ALTPS). The tourniquet was placed on the umbilical ligament if a staged right trisectionectomy was planned, and on Cantlie's line for staged right hepatectomy.

RESULTS

From September 2011, 22 ALTPS procedures were carried out (right trisectionectomy in 15, right hepatectomy in 7). Median FLR at 7 days increased from 410 to 700 ml (median increase 61 (range 33-189) per cent). The median duration of the first stage was 125 min and no patient received a blood transfusion. The median duration of the second stage was 150 min and five patients required a blood transfusion. Fourteen patients had complications, most frequently infected collections, and five patients developed postoperative liver failure. Two patients died.

CONCLUSION

The ALTPS technique achieved adequate hypertrophy of the FLR after 7 days. It may provide a less aggressive modification of the ALPPS procedure.

Different clinical presentation of Klinefelter's syndrome in monozygotic twins

There is a wide variability in the clinical presentation of Klinefelter's syndrome. We report the case of a 45-year-old man who was incidentally diagnosed a 47,XXY/46,XY karyotype in a bone marrow aspiration (case 1). He presented hypogonadic features with undetectable testosterone levels and a height in accordance with mid-parental height. He had a monozygous sibling (case 2) who did not show clinical signs of hypogonadism and whose height exceeded mid-parental height. Both patients had presented language disorders since childhood. The karyotype of lymphocytes in peripheral blood of both subjects was compatible with mosaic Klinefelter's syndrome (46,XY/47,XXY). Testosterone replacement was initiated in case 1. Lack of testicular involvement due to mosaicism and the overexpression of the SHOX gene in case 2 could explain the marked differences in phenotype in these homozygous twins.

Phenotypic characterization of hereditary epithelial ovarian cancer based on a tissue microarray study

The pathologic and immunohistochemical features of familial epithelial ovarian cancers are not well understood. We have carried out a comprehensive immunohistochemical study of familial ovarian carcinomas from women with and without BRCA1 or BRCA2 mutations, in order to identify specific and/or common features among these different familial case groups (BRCA1, BRCA2 and non-BRCA1/2) and to identify markers of diagnostic value that might help to select more specific treatments. 73 familial primary ovarian carcinomas were analyzed for the expression of 40 antibodies involved in different genetic pathways using a tissue microarray. Serous carcinomas comprised the majority of all three familial case groups. On the other hand, BRCA1 and BRCA2 carcinomas have similar histopathologic features; i.e. they are often high-grade and are usually diagnosed at a more advanced FIGO stage than non-BRCA1/2 carcinomas. In our series, BRCA1 carcinomas had better clinical evolution and they also more frequently over-expressed PR and P53 than BRCA2 and non-BRCA1/2 carcinomas. Unsupervised cluster analysis and survival analysis identified ERCC1 as a potential marker of better clinical outcome for hereditary epithelial ovarian cancer.

Viability of six species of larval and non-larval helminth eggs for different conditions of temperature, pH and dryness

Helminth eggs are the most difficult biological parasites to inactivate in wastewater and sludge. In developing countries, in particular, they are present in high concentrations and are the cause of many diseases that impact seriously on the human population. The process conditions for affordable inactivation are very variable, leading to different inactivation efficiencies. Temperature, dryness, pH and the developmental stage of the eggs must be taken into consideration to achieve complete inactivation. The objective of this research was to study the inactivation of six species of larval and non-larval helminth eggs of medical importance in developing countries under controlled conditions of temperature, pH, dryness and contact time. Results showed considerable differences in inactivation conditions among helminth eggs and a high level of resistance was confirmed for the eggs of Ascaris lumbricoides and Ascaris suum. The appropriate conditions for inactivation of all types of eggs were found by applying combinations of pH, temperature and dryness. At 45 °C it was possible to inactivate all species with a pH of 5.3 and 90% dryness within 6 days. If alkalization was applied, a pH of 12.7 was sufficient over 19 days at the same conditions of dryness and temperature. From these results it is proposed that both Ascaris spp. and Taenia solium may be used as indicators of biological contamination in wastewater and sludge.