SYNCHRONOUS DIAGNOSIS OF TESTICULAR AND THYROID CANCER IN A YOUNG MALE

Testicular cancer is the most common neoplasm in young males. The early diagnosis and the appropriate treatment make it a curable malignancy in over 90% of the patients, but 6% of the patients with testicular cancer develop a second, mostly treatment-related, malignancy in another primary site many years after the first diagnosis. The simultaneous appearance of a testicular tumor with another primary neoplasm is rarely described in the literature. Here is presented an interesting case of a coexisting non-seminomatous germ cell testicular tumor with a papillary thyroid carcinoma, which was detected early during post-treatment restaging of the testicular tumor. The synchronous presence of these two neoplasms might indicate a probable common pathogenetic background. As treatment-related oncogenesis is highly improbable in this case and the common environmental factors are not known yet, the interest is focused on genetic predisposition. Recent discoveries in molecular genetics show that the two neoplasms share common genetic alterations in the RAS and BRAF genes, which affect the significant signaling pathways. Interestingly, BRAF-V600E was positive in both primary malignancies in our individual.

In vitro model to simulate multiple drugs with distinct elimination half-lives

OBJECTIVE

The prevalence of drug resistance in pathogens such as HIV and selected bacteria has been steadily rising, resulting in an increased need for using multiple agents concurrently. Agents used in these combination therapies may have different elimination half-lives in humans. There is an unmet need for in vitro models to evaluate the efficacy of these combinations to guide early drug development. In order to realistically reflect in vivo conditions, useful in vitro model systems must be capable of simulating multiple pharmacokinetic profiles with distinct elimination half-lives. The goal of this study was to experimentally simulate four pharmacokinetic profiles with distinct elimination half-lives in an in vitro hollow-fibre system.

METHODS

For illustrative purposes, fluctuating exposures of ceftriaxone were simulated with distinct half-lives of 1, 2.5, 8, and 12 hours. A parallel experimental setup was used to independently connect four supplemental reservoirs to a central reservoir. Target maximum concentration was achieved by direct drug dosing into the central reservoir; supplemental reservoirs were also dosed to offset the rapid drug elimination rate from the central reservoir. Serial pharmacokinetic samples were obtained from the central reservoir, assayed by a spectrophotometric method, and characterized by a one-compartment model.

RESULTS

The observed maximum concentrations and elimination half-lives were in agreement with the expected values obtained from the mathematical predictions.

CONCLUSIONS

This in vitro experimental system can be used to evaluate the efficacy of up to four-drug combinations against multidrug-resistant bacteria or HIV-infected mammalian cells. The established framework represents an adaptable tool to advance the field of combination therapy.

Rapid In Vitro Assessment of Antimicrobial Drug Effect Bridging Clinically Relevant Pharmacokinetics: A Comprehensive Methodology

Rapid in vitro assessment of antimicrobial drug efficacy under clinically relevant pharmacokinetic conditions is an essential element of both drug development and clinical use. Here, we present a comprehensive overview of a recently developed novel integrated methodology for rapid assessment of such efficacy, particularly against the emergence of resistant bacterial strains, as jointly researched by the authors in recent years. This methodology enables rapid in vitro assessment of the antimicrobial efficacy of single or multiple drugs in combination, following clinically relevant pharmacokinetics. The proposed methodology entails (a) the automated collection of longitudinal time-kill data in an optical-density instrument; (b) the processing of collected time-kill data with the aid of a mathematical model to determine optimal dosing regimens under clinically relevant pharmacokinetics for single or multiple drugs; and (c) in vitro validation of promising dosing regimens in a hollow fiber system. Proof-of-concept of this methodology through a number of in vitro studies is discussed. Future directions for the refinement of optimal data collection and processing are discussed.

Systematic design of pulse dosing to eradicate persister bacteria

A small fraction of infectious bacteria use persistence as a strategy to survive exposure to antibiotics. Periodic pulse dosing of antibiotics has long been considered a potentially effective strategy towards eradication of persisters. Recent studies have demonstrated through in vitro experiments that it is indeed feasible to achieve such effectiveness. However, systematic design of periodic pulse dosing regimens to treat persisters is currently lacking. Here we rigorously develop a methodology for the systematic design of optimal periodic pulse dosing strategies for rapid eradication of persisters. A key outcome of the theoretical analysis, on which the proposed methodology is based, is that bactericidal effectiveness of periodic pulse dosing depends mainly on the ratio of durations of the corresponding on and off parts of the pulse. Simple formulas for critical and optimal values of this ratio are derived. The proposed methodology is supported by computer simulations and in vitro experiments.

Deciphering longitudinal optical-density measurements to guide clinical dosing regimen design: A model-based approach

BACKGROUND

Model-based analysis of longitudinal optical density measurements from a bacterial suspension exposed to antibiotics has been proposed as a potentially efficient and effective method for extracting useful information to improve the individualized design of treatments for bacterial infections. To that end, the authors developed in previous work a mathematical modeling framework that can use such measurements for design of effective dosing regimens.

OBJECTIVES

Here we further explore ways to extract information from longitudinal optical density measurements to predict bactericidal efficacy of clinically relevant antibiotic exposures.

METHODS

Longitudinal optical density measurements were collected in an automated instrument where Acinetobacter baumannii, ATCC BAA747, was exposed to ceftazidime concentrations of 1, 4, 16, 64, and 256 mg/L and to ceftazidime/amikacin concentrations of 1/0.5, 4/2, 16/8, 64/32, and 256/128 (mg/L)/(mg/L) over 20 h. Calibrated conversion of measurements produced total (both live and dead) bacterial cell concentration data (CFU/mL equivalent) over time. Model-based data analysis predicted the bactericidal efficacy of ceftazidime and of ceftazidime/amikacin (at ratio 2:1) for periodic injection every 8 h and subsequent exponential decline with half-life of 2.5 h. Predictions were experimentally tested in an in vitro hollow-fiber infection model, using peak concentrations of 60 and 150 mg/L for injected ceftazidime and of 40/20 (mg/L)/(mg/L) for injected ceftazidime/amikacin.

RESULTS

Model-based analysis predicted low (<62%) confidence in clinically relevant suppression of the bacterial population by periodic injections of ceftazidime alone, even at high peak concentrations. Conversely, analysis predicted high (>95%) confidence in bacterial suppression by periodic injections of ceftazidime/amikacin combinations at a wide range of peak concentrations ratioed at 2:1. Both predictions were experimentally confirmed in an in vitro hollow fiber infection model, where ceftazidime was periodically injected at peak concentrations 60 and 150 mg/L (with predicted suppression confidence 38% and 59%, respectively) and a combination of ceftazidime/amikacin was periodically injected at peak concentrations 40/20 (mg/L)/(mg/L) (with predicted suppression confidence 98%).

CONCLUSIONS

The paper highlights the potential of clinicians using the proposed mathematical framework to determine the utility of different antibiotics to suppress a patient-specific isolate. Additional studies will be needed to consolidate and expand the utility of the proposed method.

Revisiting the standard for modeling the spread of infectious diseases

The COVID-19 epidemic brought to the forefront the value of mathematical modelling for infectious diseases as a guide to help manage a formidable challenge for human health. A standard dynamic model widely used for a spreading epidemic separates a population into compartments-each comprising individuals at a similar stage before, during, or after infection-and keeps track of the population fraction in each compartment over time, by balancing compartment loading, discharge, and accumulation rates. The standard model provides valuable insight into when an epidemic spreads or what fraction of a population will have been infected by the epidemic's end. A subtle issue, however, with that model, is that it may misrepresent the peak of the infectious fraction of a population, the time to reach that peak, or the rate at which an epidemic spreads. This may compromise the model's usability for tasks such as "Flattening the Curve" or other interventions for epidemic management. Here we develop an extension of the standard model's structure, which retains the simplicity and insights of the standard model while avoiding the misrepresentation issues mentioned above. The proposed model relies on replacing a module of the standard model by a module resulting from Padé approximation in the Laplace domain. The Padé-approximation module would also be suitable for incorporation in the wide array of standard model variants used in epidemiology. This warrants a re-examination of the subject and could potentially impact model-based management of epidemics, development of software tools for practicing epidemiologists, and related educational resources.

Ziegler and Nichols meet Kermack and McKendrick: Parsimony in dynamic models for epidemiology

The COVID-19 crisis popularized the importance of mathematical modeling for managing epidemics. A celebrated pertinent model was developed by Kermack and McKendrick about a century ago. A simplified version of that model has long been used and became widely popular recently, even though it has limitations that its originators had clearly articulated and warned against. A basic limitation is that it unrealistically assumes zero time to recovery for most infected individuals, thus underpredicting the peak of infectious individuals in an epidemic by a factor of as much as about 2. One could avoid this limitation by returning to the original comprehensive model, at the cost of higher complexity. To remedy that, we blend Ziegler-Nichols modeling ideas, developed for automatic controller tuning, with Kermack-McKendrick ideas to develop novel model structures that predict infectious peaks accurately yet retain simplicity. We illustrate these model structures with computer simulations on real epidemiological data.

SIMULTANEOUS IN VITRO SIMULATION OF MULTIPLE ANTIMICROBIAL AGENTS WITH DIFFERENT ELIMINATION HALF-LIVES IN A PRE-CLINICAL INFECTION MODEL

Combination therapy for treatment of multi-drug resistant bacterial infections is becoming common. In vitro testing of drug combinations under realistic pharmacokinetic conditions is needed before a corresponding combination is eventually put into clinical use. The current standard for design of such in vitro simulations for drugs with different half-lives is heuristic and limited to two drugs. To address that void, we develop a rigorous design method suitable for an arbitrary number of N drugs with different half-lives. The method developed offers substantial flexibility and produces novel designs even for two drugs. Explicit design equations are rigorously developed and are suitable for immediate use by experimenters. These equations were used in experimental verification using a combination of three antibiotics with distinctly different half-lives. In addition to antibiotics, the method is applicable to any anti-infective or anti-cancer drugs with distinct elimination pharmacokinetics.

Vaccine third dose and cancer patients: necessity or luxury?

The current state of the SARS-CoV-2 pandemic is an equilibrium between expanding vaccine coverage on the one hand, and emergence of variants of concern which compromise vaccine effectiveness and enhance viral transmission on the other. Inequity in vaccine distribution, primarily an ethical issue, challenges this equilibrium, as industrialized countries prepare to administer a third booster dose to their population. Solid tumor cancer patients typically respond well to initial full vaccination and someone could argue that they should not be prioritized for an adjuvant third dose, since protection from severe disease has largely been achieved with the two-dose regimen. Nevertheless, their immune status is dynamic and not all of them exhibit an adequate immune response. A booster third dose is necessary for the inadequate responders, while it will result in better protection of all patients from mild disease as well, which if presented could have ominous consequences due to their overall frailty, and their need to adhere to strict therapeutic schemes. International scientific and public health communities should develop approaches that allow for wide immediate vaccination coverage of the developing world, in parallel with administration of adjuvant doses to solid tumor cancer patients (and other at-risk categories) of the developed nations, in order to avoid prolonging the pandemic, which will be prospectively against cancer patients' best interest.

Experimental Validation of a Mathematical Framework to Simulate Antibiotics with Distinct Half-Lives Concurrently in an In Vitro Model

Antimicrobial resistance has been steadily increasing in prevalence, and combination therapy is commonly used to treat infections due to multidrug resistant bacteria. Under certain circumstances, combination therapy of three or more drugs may be necessary, which makes it necessary to simulate the pharmacokinetic profiles of more than two drugs concurrently in vitro. Recently, a general theoretical framework was developed to simulate three drugs with distinctly different half-lives. The objective of the study was to experimentally validate the theoretical model. Clinically relevant exposures of meropenem, ceftazidime, and ceftriaxone were simulated concurrently in a hollow-fiber infection model, with the corresponding half-lives of 1, 2.5, and 8 h, respectively. Serial samples were obtained over 24 h and drug concentrations were assayed using validated LC-MS/MS methods. A one-compartment model with zero-order input was used to characterize the observed concentration-time profiles. The experimentally observed half-lives corresponding to exponential decline of all three drugs were in good agreement with the respective values anticipated at the experiment design stage. These results were reproducible when the experiment was repeated on a different day. The validated benchtop setup can be used as a more flexible preclinical tool to explore the effectiveness of various drug combinations against multidrug resistant bacteria.

Optimizing pharmacokinetics/pharmacodynamics of β-lactam/β-lactamase inhibitor combinations against high inocula of ESBL-producing bacteria

OBJECTIVES

Reduced in vitro β-lactam activity against a dense bacterial population is well recognized. It is commonly attributed to the presence of β-lactamase(s) and it is unknown whether the inoculum effect could be diminished by a β-lactamase inhibitor. We evaluated different β-lactam/β-lactamase inhibitor combinations in suppressing a high inoculum of ESBL-producing bacteria.

METHODS

Three clinical isolates expressing representative ESBLs (CTX-M-15 and SHV-12) were examined. The impact of escalating β-lactamase inhibitor (tazobactam or avibactam) concentrations on β-lactam (piperacillin or ceftazidime) MIC reduction was characterized by an inhibitory sigmoid Emax model. The effect of various dosing regimens of β-lactam/β-lactamase inhibitor combinations was predicted using %T>MICi and selected exposures were experimentally validated in a hollow-fibre infection model over 120 h. The threshold exposure to suppress bacterial regrowth was identified using recursive partitioning.

RESULTS

A concentration-dependent reduction in β-lactam MIC was observed (r2 ≥0.93). Regrowth could be suppressed in all six experiments using %T>MICi ≥73.6%, but only one out of six experiments below the threshold (P = 0.015). The exposures to suppress regrowth might be attained using the clinical dose of avibactam, but a much higher dose than the standard dose would be needed for tazobactam.

CONCLUSIONS

A dense population of ESBL-producing bacteria could be suppressed by an optimized dosing regimen of selected β-lactam/β-lactamase inhibitor combinations. The reversibility of enzyme inhibition could play an important role in diminishing the inoculum effect. In vivo investigations to validate these findings are warranted.

The Lambert Function Should Be in the Engineering Mathematical Toolbox

Discovered well over two centuries ago and little used for long, the Lambert function has emerged in an increasing number of science and engineering applications in the last couple of decades. Here we present case studies relevant to the diverse interests of chemical engineers. We show how the Lambert function can be used for both analysis and computation. While some of these studies expound on prior literature results, the rest are new. We conjecture that if this tool becomes more widely known, many more instances of application will appear. Therefore, given its simplicity and usefulness, we would reasonably argue that the Lambert function should be included in the standard mathematical toolbox of chemical engineers.

Effects of anti-inflammatory treatment and surgical intervention on endothelial glycocalyx, peripheral and coronary microcirculation and myocardial deformation in inflammatory bowel disease patients

Funding Acknowledgements

Type of funding sources: Foundation. Main funding source(s): EOMIFNE (Hellenic Society of IBD study)

Introduction

IBD alter gastrointestinal physiology and mucosal immunity through a complex inflammatory process which leads to significant arterial endothelial dysfunction and modification of cardiac structure and function. This study is performed to test the hypothesis that treatment with TNF-a inhibitor or surgical intervention improves cardiovascular function through anti-inflammatory mechanisms.

Methods

57 IBD patients (45 CD and 12 UC, 40 ± 8 years, 57% male) were examined at baseline and 4 months after pharmaceutical (antiTNF-a) or surgical intervention. Subjects with a history of established cardiovascular risk factors were excluded.

We measured a) carotid-femoral pulse wave velocity (PWV - Complior SP ALAM) and augmentation index (AI), b) flow mediated dilatation (FMD) of the brachial artery), c) perfused boundary region (PBR) of the sublingual arterial microvessels, d) LV longitudinal strain (GLS) and (PWV/GLS) as a marker of ventricular-arterial coupling, e) peak LV twisting, peak twisting velocity (pTwVel) and peak untwisting velocity (pUtwVel) using speckle tracking echocardiography, f) mitral annulus velocities by tissue doppler imaging (S’ and E’) and mitral inflow velocity (E), g) coronary flow reserve (CFR) by Doppler echocardiography, h) C-reactive protein (CRP), white blood cells (WBC).

IBD severity was quantified using Mayo score and Harvey-Bradshaw Index (HBI) for UC and CD respectively.

Results

At baseline, the disease severity score and the WBC values were significantly correlated with peripheral PWV (r = 0.3, p &lt; 0.05 and r = 0.364, p &lt; 0.05), while central arterial AI was associated with median arterial pressure (r = 0.479, p &lt; 0.05), lateral and septal mitral E’ velocity (r=-0.651, p &lt; 0.05 and r=-0.587, p &lt; 0.05). Four months after treatment, there was a reduction of CRP (13 ± 2.8 mg/L vs 3.9 ± 1.2 mg/L, p &lt; 0.05), CFR (2.5 ± 0.08 vs 3.1 ± 0.11, p &lt; 0.05) and PBR5-25 (2.27 ± 0.06 vs 2.09 ± 0.05 μm, p &lt; 0.05) more significantly in pharmaceutical group (p &lt; 0.05 vs p = 0.23). Moreover, there was an improvement of GLS (-18.6 ± 0.37 vs -20 ± 0.34, p &lt; 0.05), LS-4ch (-18.3 ± 0.47 vs -19.3 ± 0.41, p &lt; 0.05), GcircS (-18.1 ± 0.7 vs -20.1 ± 0.9, p &lt; 0.05) and FMD (7.2%±0.6 vs 11.8%±1.4, p &lt; 0.05). Moreover, there was an overall improvement of PWV/GLS (-0.49 ± 0.02 vs -0.43 ± 0.02, p &lt; 0.05). It was greater after with anti-TNFa therapy compared to surgery (p &lt; 0.05 vs p = 0.1) and particular for the GLS component (p &lt; 0.05 vs p = 0.07). The difference in PBR5-25 was significantly correlated with the difference in GLS (r=-0.403, p &lt; 0.05) and PWV/GLS (r = 0.421, p &lt; 0.05).

Conclusion

IBD severity is associated with vascular and diastolic dysfunction, with significant improvement after anti-inflammatory treatment. Systemic anti-TNFa inhibition leads to significant improvement in myocardial deformation, endothelial and coronary microcirculatory function compared with local intestinal surgical intervention, possibly through a systemic reduction of excess inflammatory burden.

Azasteroid Alkylators as Dual Inhibitors of AKT and ERK Signaling for the Treatment of Ovarian Carcinoma

(1) Background: Previous findings show that lactam steroidal alkylating esters display improved therapeutic efficacy with reduced toxicity. The aim of this study was to evaluate the anticancer activity of two newly synthesized aza-steroid alkylators (ENGA-L06E and ENGA-L08E) against human ovarian carcinoma cells, and consequently, the dual inhibition of RAS/PI3K/AKT and RAS/RAF/MEK/ERK signaling pathways, both of which are closely associated with ovarian cancer; (2) Methods: The in vitro cytostatic and cytotoxic effects of ENGA-L06E and ENGA-L08E were evaluated in a panel of five human ovarian cancer cell lines, as well as in in vivo studies. ENGA-L06E and ENGA-L08E, in addition to another two aniline-mustard alkylators, POPAM and melphalan (L-PAM), were utilized in order to determine the acute toxicity and antitumor efficacy on two human ovarian xenograft models. Also, in silico studies were performed in order to investigate the dual inhibition of ENGA-L06E and ENGA-L08E on RAS/PI3K/AKT and RAS/RAF/MEK/ERK signaling pathways; (3) Results: Both, in vitro and in vivo studies demonstrated that ENGA-L06E and ENGA-L08E were significantly more effective with a lower toxicity profile in comparison to POPAM and L-PAM alkylators. Moreover, in silico studies demonstrated that the two new aza-steroid alkylators could act as efficient inhibitors of the phosphorylation of AKT and ERK1/2 molecules; and (4) Conclusions: Both ENGA-L06E and ENGA-L08E demonstrated high anticancer activity through the inhibition of the PI3K-AKT and KRAS-ERK signaling pathways against human ovarian carcinoma, and thus constituting strong evidence towards further clinical development.

P831 Anti-inflammatory treatment improves endothelial glycocalyx, peripheral and coronary microcirculatory function and myocardial deformation in inflammatory bowel disease patients

Funding Acknowledgements

Hellenic Society of IBD study (EOMIFNE)

Introduction

Inflammatory bowel diseases (IBD) alter gastrointestinal physiology and mucosal immunity through a complex inflammatory process. The extensive inflammation leads to significant arterial endothelial dysfunction as well as modification of cardiac structure and function. This study is performed to test the hypothesis that treatment with TNF-a inhibitor or surgical intervention in the IBD population improves cardiovascular function through anti-inflammatory mechanisms.

Methods

Thirty-seven IBD patients (28 CD and 9 UC, 39 ± 12 years, 62% male) were examined at baseline and 4 months after pharmaceutical (TNF-a inhibitor) (16 patients) or surgical intervention (21 patients). Subjects with a history of established cardiovascular risk factors were excluded.

We measured a) carotid-femoral pulse wave velocity (PWV - Complior SP ALAM), central systolic blood pressure (cSBP) and augmentation index (AI), b) flow mediated dilatation (FMD) of the brachial artery), c) perfused boundary region(PBR) of the sublingual arterial microvessels using Sideview Darkfield imaging, d) LV longitudinal strain (GLS), strain rate (GLSR) and (PWV/GLS) as a marker of ventricular-arterial coupling, e) peak LV twisting, peak twisting velocity (pTwVel) and peak untwisting velocity (pUtwVel) using speckle tracking echocardiography, f) mitral annulus velocities by tissue doppler imaging (S’ and E’) and mitral inflow velocity (E), g) coronary flow reserve (CFR) by Doppler echocardiography, h) C-reactive protein (CRP), white blood cells (WBC).

IBD severity was quantified using Mayo score and Harvey-Bradshaw Index (HBI) for UC and CD respectively, and correlated with the cardiovascular disease markers.

Results

At baseline, the disease severity score was significantly correlated with markers of diastolic dysfunction (lateral mitral E’ velocity r=-0.352, p &lt; 0.05, UntwVelE r = 0.389, p &lt; 0.05), while the WBC values were negatively associated with lateral mitral E’ velocity: r=-0.5, p &lt; 0.05 and CFRvti (r=-0.332, p = 0.05). Four months after anti-inflammatory treatment, there was a reduction of CRP (15.5 ± 4.7 mg/L vs 5.1 ± 2.1 mg/L, p &lt; 0.05) and WBC values (8.6 ± 0.6 vs 6.6 ± 0.7 x 103, p = 0.06). Moreover, post-treatment, there was a significant reduction of central arterial AI (3.58 ± 4.13 vs 0 ± 4.96, p &lt; 0.05), PBR10-19 (2.47 ± 0.09 vs 2.24 ± 0.08 μm, p &lt; 0.05) and PBR5-25 (2.31 ± 0.08 vs 2.14 ± 0.06 μm, p = 0.05) and increase of FMD (7.6%±0.7 vs 12.2%±1.7, p &lt; 0.05), CFR (2.6 ± 0.1 vs 3.2 ± 0.14, p &lt; 0.05), GLS (-18.7 ± 0.46 vs -20 ± 0.49, p &lt; 0.05) and PWV/GLS (-0,48 ± 0.027 vs -0,42 ± 0.028, p &lt; 0.05). No difference in the examined markers was observed between patients treated with anti-TNFa or surgery (p = NS).

Conclusion

IBD severity is associated with vascular and diastolic dysfunction. Anti-TNFa inhibition treatment or surgical intervention in IBD lead to improved myocardial deformation, endothelial and coronary microcirculatory function possibly through the reduction of excess inflammatory burden.

A Holistic Approach to Assessment of Population Exposure to Radiation: Challenges and Initiatives of a Regulatory Authority

A regulatory authority for radiation safety should continuously evaluate and improve the national safety framework, in line with current requirements and standards. In this context, the Greek Atomic Energy Commission initiated a series of concerted actions. The radiation dose to the population due to public and medical exposures was assessed. The assessment of dose due to public exposure was based on measurements of radon concentrations in dwellings, radionuclide concentrations in environmental samples, and air dose rates; the assessment of dose due to medical exposure was based on dose measurements for typical examinations or procedures and data on their frequency. The mean effective dose to a member of the population was found to be 4.5 mSv (1.8 mSv and 2.7 mSv from medical and public exposures, respectively). Regarding occupational exposure, aircrew dose assessment, eye lens monitoring, and the national dose registry were significantly improved. With respect to artificial tanning (sun beds), the ultraviolet radiation produced was assessed and the practices followed were observed. Results demonstrated exceedance of the 0.3 W m erythema effective irradiance limit set in European Union standards by 63.5% of the sun beds measured, along with general noncompliance with standards. An overarching activity was the upgrade of the Greek Atomic Energy Commission information system in order to collect and disseminate radiation data electronically, launch a networking strategy for interaction with stakeholders, and facilitate the process of regulatory control. In response to the above findings, regulatory actions have been initiated.

Access to Genetic Testing Impacts Oncologists´ Decisions on Ovarian Cancer Personalized Treatment: Lessons Learned From a National Program in Greece

Background: State health insurance authorities in Greece do not reimburse genetic testing for cancer predisposition. The Hellenic Society of Medical Oncology has launched and carries out a national program covering genetic testing for BRCA1/2 mutations detection, with the financial support of pharmaceutical industry. Aim: This analysis evaluates how, during this program, access to genetic testing transformed the oncologists' therapeutic approach toward their ovarian cancer patients and how the results impacted treatment decisions concerning PARP inhibitors. Adoption of testing by healthy relatives and timing of testing in the disease continuum were also evaluated. Methods: Adult patients with high-grade epithelial ovarian carcinoma, irrespectively of family history or age at diagnosis were eligible for this program. Genetic counseling was recommended before testing, and both were offered at no financial cost. First degree family members of pathogenic mutation carriers were also offered free counseling and testing. Results: From March 2015 through January 2018, 708 patients were enrolled and tested. One hundred and forty seven (20.7%) mutation carriers were identified, 102 (14.4%) in BRCA1 and 45 (6.3%) in BRCA2 gene. Testing was more often pursued at initial diagnosis (61%) than at recurrence (39%), as recorded for 409 patients with available relevant information. During the 1st year of the program, average monthly tests performed were 25.1, while during the 3rd year this number increased to 34.3 tests per month. Among patients who tested positive for deleterious BRCA1/2 mutations, relapse was reported in 58 patients, 94.8% of which (n= 55) received treatment with the PARP inhibitor olaparib as per its indication. Family members of 21 patients (14.3%), out of the 147 who tested positive, received genetic counseling and testing for the mutation identified in the context of the program. Conclusion: Free access to genetic testing for BRCA1/2 for ovarian cancer patients and genetic consultation facilitates testing uptake, affects common clinical practice & has major impact on patients and their families. Still, diffusion of genetic information and broader testing of family members require further efforts by the oncological community.

Metastatic soft tissue sarcoma: current treatment landscape and future perspectives

INTRODUCTION

The therapeutic armamentarium for advanced soft tissue sarcoma (STS) has increased over the last few years. Doxorubicin monotherapy or in combination is now the established first line treatment. Beyond first line treatment, no standard therapy has been established. Novel drugs have reached the late-clinical stage development demonstrating to be effective in controlled studies. While these novel treatments can be beneficial to a subset of patients, even producing long lasting remissions, a significant fraction of the STS population derives limited benefit. This is due to the fact that STS is a very heterogeneous disease with different histopathologic features, biological characteristics and clinical behaviour. Areas covered: The primary aim of this review is to summarize data from recent phase III clinical trials in unselected STS population, and to discuss their impact on the current clinical practice. Phase I-II trials of special interest are discussed as well. Expert commentary: Although our efforts in this research task are ongoing, the integration of biological therapies, the anti-angiogenesis targeted treatments as well as immunotherapy that may further improve the long term control of advanced STS are of special clinical interest. Clinical management of advanced STS should be tailored to each patient in order to optimize therapy.

Modeling Heterogeneous Bacterial Populations Exposed to Antibiotics: The Logistic-Dynamics Case

In typical in vitro tests for clinical use or development of antibiotics, samples from a bacterial population are exposed to an antibiotic at various concentrations. The resulting data can then be used to build a mathematical model suitable for dosing regimen design or for further development. For bacterial populations that include resistant subpopulations-an issue that has reached alarming proportions-building such a model is challenging. In prior work, we developed a related modeling framework for such heterogeneous bacterial populations following linear dynamics when exposed to an antibiotic. We extend this framework to the case of logistic dynamics, common among strongly resistant bacterial strains. Explicit formulas are developed that can be easily used in parameter estimation and subsequent dosing regimen design under realistic pharmacokinetic conditions. A case study using experimental data from the effect of an antibiotic on a gram-negative bacterial population exemplifies the usefulness of the proposed approach.

Microwave endometrial ablation after endometrial curettage for the management of heavy menstrual bleeding

OBJECTIVES

The aim of the present study was to evaluate the eticacy of microwave endometrial ablation after endometrial curettage, in selected patients with heavy menstrual bleeding.

MATERIAL AND METHODS

Thirty-two premenopausal women with heavy menstrual bleeding underwent microwave endometrial ablation at the Department of Obstetrics and Gynecology of the University of Patras Medical School. All patients did not respond to previous medical treatment, had completed their childbearing, and did not desire future fertility. The authors chose endometrial curettage rather than hormonal pretreatment (GnRH analogs, danazol) for endometrial preparation. Posttreatment follow up protocol included physical and ultrasonographic evaluation at three, six, nine, and 12 months for the first year and yearly after.

RESULTS

The authors had no cases of uterine perforation, thermal injury to adjacent organs, and infection or sepsis. During follow up, there was a gradual decrease in amenorrhea rate (90.6% - 68.8%) and in satisfaction rate (90.6% - 71.9%). Moreover during follow up, eight women underwent to total abdominal hysterectomy. Among them, seven women had uterine myomas and one woman had adenomyosis.

CONCLUSIONS

Endometrial preparation with endometrial curettage seems to be a good alternative to hormonal pretreatment. It has the advantage of avoiding delays, side effects, and cost of hormonal pretreatment. Moreover, microwave endometrial ablation after endometrial curettage is successful and highly acceptable.

Storage stability studies for tributyltin determination in human urine samples using headspace solid-phase microextraction and gas chromatography mass spectrometry

A headspace solid-phase micro-extraction (HS-SPME) method was employed in order to study the effect of storage conditions of human urine samples spiked with tributyltin (TBT) using gas chromatography and mass spectrometry. To render the analyte more volatile, the derivatization (ethylation) was made in situ by sodium tetraethylborate (NaBEt(4) ), which was added directly to dilute unpreserved urine samples and in buffers of similar acidity. The stability of TBT in human urine matrix was compared with the stability of TBT in buffer solutions of similar pH value. Critical parameters of storage conditions such as temperature and time, which affect the stability of TBT in this kind of matrix, were examined extensively. The tests showed that the stability of TBT remains practically satisfactory for a maximum of 2 days of storage either at +4 or 20°C. Greater variations were observed in the concentration of TBT in human urine samples at +4°C and lower ones at -20°C over a month's storage. The freeze-thaw cycles have negative effect on the stability and should be kept to a minimum. The results from spiked urine samples are also discussed in comparison to those acquired from buffer solutions of equal TBT concentration.

A novel approach to pharmacodynamic assessment of antimicrobial agents: new insights to dosing regimen design

Pharmacodynamic modeling has been increasingly used as a decision support tool to guide dosing regimen selection, both in the drug development and clinical settings. Killing by antimicrobial agents has been traditionally classified categorically as concentration-dependent (which would favor less fractionating regimens) or time-dependent (for which more frequent dosing is preferred). While intuitive and useful to explain empiric data, a more informative approach is necessary to provide a robust assessment of pharmacodynamic profiles in situations other than the extremes of the spectrum (e.g., agents which exhibit partial concentration-dependent killing). A quantitative approach to describe the interaction of an antimicrobial agent and a pathogen is proposed to fill this unmet need. A hypothetic antimicrobial agent with linear pharmacokinetics is used for illustrative purposes. A non-linear functional form (sigmoid Emax) of killing consisted of 3 parameters is used. Using different parameter values in conjunction with the relative growth rate of the pathogen and antimicrobial agent concentration ranges, various conventional pharmacodynamic surrogate indices (e.g., AUC/MIC, Cmax/MIC, %T>MIC) could be satisfactorily linked to outcomes. In addition, the dosing intensity represented by the average kill rate of a dosing regimen can be derived, which could be used for quantitative comparison. The relevance of our approach is further supported by experimental data from our previous investigations using a variety of gram-negative bacteria and antimicrobial agents (moxifloxacin, levofloxacin, gentamicin, amikacin and meropenem). The pharmacodynamic profiles of a wide range of antimicrobial agents can be assessed by a more flexible computational tool to support dosing selection.

A comparison of pain and anxiety associated with the administration of maxillary local analgesia with Wand and conventional technique

AIM

This was to compare the sensation of pain when injections were given using the Wand computer controlled local analgesia (LA) system and a conventional technique in children of pre-school and school age.

METHODS

38 children were randomly assigned to either a treatment or control group. The treatment (Wand) group consisted of 20 children, while the control group (conventional LA technique) consisted of 18 children. The children were aged between 39.0 and 120.0 months with a mean age of 81.9 months (SD- 23.2). One operator carried out all local analgesia administrations. Pain sensation was rated using the VAS scale by the operator, each child and their parent. Anxiety was rated using the Venham scale.

RESULTS

No statistical difference in pain sensation and anxiety was found when the Wand was used, compared with the conventional technique (P=0.710, P=0.976). The results also showed no significant difference in anxiety change between males and females in the two groups (P=0.714).

CONCLUSION

There was no difference in the pain or anxiety experienced by the children in the conventional and Wand group.