Deltamethrin and transfluthrin select for distinct transcriptomic responses in the malaria vector Anopheles gambiae

BACKGROUND

The widespread use of pyrethroid insecticides in Africa has led to the development of strong resistance in Anopheles mosquitoes. Introducing new active ingredients can contribute to overcome this phenomenon and ensure the effectiveness of vector control strategies. Transfluthrin is a polyfluorinated pyrethroid whose structural conformation was thought to prevent its metabolism by cytochrome P450 monooxygenases in malaria vectors, thus representing a potential alternative for managing P450-mediated resistance occurring in the field. In this study, a controlled selection was used to compare the dynamics of resistance between transfluthrin and the widely used pyrethroid deltamethrin in the mosquito Anopheles gambiae. Then, the associated molecular mechanisms were investigated using target-site mutation genotyping and RNA-seq.

METHODS

A field-derived line of An. gambiae carrying resistance alleles at low frequencies was used as starting material for a controlled selection experiment. Adult females were selected across 33 generations with deltamethrin or transfluthrin, resulting in three distinct lines: the Delta-R line (selected with deltamethrin), the Transflu-R line (selected with transfluthrin) and the Tiassale-S line (maintained without selection). Deltamethrin and transfluthrin resistance levels were monitored in each selected line throughout the selection process, as well as the frequency of the L1014F kdr mutation. At generation 17, cross-resistance to other public health insecticides was investigated and transcriptomes were sequenced to compare gene transcription variations and polymorphisms associated with adaptation to each insecticide.

RESULTS

A rapid increase in resistance to deltamethrin and transfluthrin was observed throughout the selection process in each selected line in association with an increased frequency of the L1014F kdr mutation. Transcriptomic data support a broader response to transfluthrin selection as compared to deltamethrin selection. For instance, multiple detoxification enzymes and cuticle proteins were specifically over-transcribed in the Transflu-R line including the known pyrethroid metabolizers CYP6M2, CYP9K1 and CYP6AA1 together with other genes previously associated with resistance in An. gambiae.

CONCLUSION

This study confirms that recurrent exposure of adult mosquitoes to pyrethroids in a public health context can rapidly select for various resistance mechanisms. In particular, it indicates that in addition to target site mutations, the polyfluorinated pyrethroid transfluthrin can select for a broad metabolic response, which includes some P450s previously associated to resistance to classical pyrethroids. This unexpected finding highlights the need for an in-depth study on the adaptive response of mosquitoes to newly introduced active ingredients in order to effectively guide and support decision-making programmes in malaria control.

Retrospective study to estimate the prevalence and describe the clinicopathological characteristics, treatments received, and outcomes of HER2-low breast cancer

BACKGROUND

Approximately 80% of all breast cancers (BCs) are currently categorized as human epidermal growth factor receptor 2 (HER2)-negative [immunohistochemistry (IHC) 0, 1+, or 2+/in situ hybridization (ISH) negative]; approximately 60% of BCs traditionally categorized as HER2-negative express low levels of HER2. HER2-low (IHC 1+ or IHC 2+/ISH-) status became clinically actionable with approval of trastuzumab deruxtecan to treat unresectable/metastatic HER2-low BC. Greater understanding of patients with HER2-low disease is urgently needed.

PATIENTS AND METHODS

This global, multicenter, retrospective study (NCT04807595) included tissue samples from patients with confirmed HER2-negative unresectable/metastatic BC [any hormone receptor (HR) status] diagnosed from 2014 to 2017. Pathologists rescored HER2 IHC-stained slides as HER2-low (IHC 1+ or IHC 2+/ISH-) or HER2 IHC 0 after training on low-end expression scoring using Ventana 4B5 and other assays at local laboratories (13 sites; 10 countries) blinded to historical scores. HER2-low prevalence and concordance between historical scores and rescores were assessed. Demographics, clinicopathological characteristics, treatments, and outcomes were examined.

RESULTS

In rescored samples from 789 patients with HER2-negative unresectable/metastatic BC, the overall HER2-low prevalence was 67.2% (HR positive, 71.1%; HR negative, 52.8%). Concordance was moderate between historical and rescored HER2 statuses (81.3%; κ = 0.583); positive agreement was numerically higher for HER2-low (87.5%) than HER2 IHC 0 (69.9%). More than 30% of historical IHC 0 cases were rescored as HER2-low overall (all assays) and using Ventana 4B5. There were no notable differences between HER2-low and HER2 IHC 0 in patient characteristics, treatments received, or clinical outcomes.

CONCLUSIONS

Approximately two-thirds of patients with historically HER2-negative unresectable/metastatic BC may benefit from HER2-low-directed treatments. Our data suggest that HER2 reassessment in patients with historical IHC 0 scores may be considered to help optimize selection of patients for treatment. Further, accurate identification of patients with HER2-low BC may be achieved with standardized pathologist training.

Exposure of Anopheles gambiae larvae to a sub-lethal dose of an agrochemical mixture induces tolerance to adulticides used in vector control management

The heavy use of pesticides in agricultural areas often leads to the contamination of nearby mosquito larvae breeding sites. Exposure to complex mixtures of agrochemicals can affect the insecticide sensitivity of mosquito larvae. Our study objective was to determine whether agrochemical residues in Anopheline larval breeding sites can affect the tolerance of adults to commonly used adulticides. We focussed on Fludora® Fusion, a vector control insecticide formulation combining two insecticides (deltamethrin and clothianidin) with different modes of action. An. gambiae larvae were exposed to a sub-lethal dose of a mixture of agrochemical pesticides used in a highly active agricultural area on the Ivory Coast. Comparative bioassays with Fludora Fusion mixture and its two insecticide components (deltamethrin and clothianidin) were carried out between adult mosquitoes exposed or not to the agrochemicals at the larval stage. A transcriptomic analysis using RNA sequencing was then performed on larvae and adults to study the molecular mechanisms underlying the phenotypic changes observed. Bioassays revealed a significantly increased tolerance of adult females to clothianidin (2.5-fold) and Fludora Fusion mixture (2.2-fold) following larval exposure to agrochemicals. Significantly increased tolerance to deltamethrin was not observed suggesting that insecticide exposure affects the adult efficacy of the Fludora Fusion mixture mainly through mechanisms acting on clothianidin. Transcriptomic analysis revealed the potential of agrochemicals to induce various resistance mechanisms including cuticle proteins, detoxification action and altered insecticide sequestration. These results suggest that although the Fludora Fusion mixture is effective for adult vector control, its efficacy may be locally affected by the ecological context. The present study also suggests that, although the complex interactions between the use of agrochemicals and vector control insecticides are difficult to decipher in the field, they still must be considered in the context of insecticide resistance management programmes.

Addressing the COVID-19 pandemic challenges for operational adaptations of a cluster randomized controlled trial on dengue vector control in Malaysia

Introduction

The COVID-19 pandemic placed an unprecedented overload on healthcare system globally. With all medical resources being dedicated to contain the spread of the disease, the pandemic may have impacted the burden of other infectious diseases such as dengue, particularly in countries endemic for dengue fever. Indeed, the co‐occurrence of COVID‐19 made dengue diagnosis challenging because of some shared clinical manifestations between the two pathogens. Furthermore, the sudden emergence and novelty of this global public health crisis has forced the suspension or slow-down of several research trials due to the lack of sufficient knowledge on how to handle the continuity of research trials during the pandemic. We report on challenges we have faced during the COVID-19 pandemic and measures that were implemented to continue the iDEM project (intervention for Dengue Epidemiology in Malaysia).

Methods

This randomized controlled trial aims to assess the effectiveness of Integrated Vector Management (IVM) on the incidence of dengue in urban Malaysia by combining: targeted outdoor residual spraying (TORS), deployment of auto-dissemination devices (ADDs), and active community engagement (CE). Our operational activities started on February 10, 2020, a few weeks before the implementation of non-pharmaceutical interventions to contain the spread of COVID-19 in Malaysia.

Results

The three main issues affecting the continuity of the trial were: ensuring the safety of field workers during the interventions; ensuring the planned turnover of TORS application and ADD deployment and services; and maintaining the CE activities as far as possible.

Conclusions

Even though the pandemic has created monumental challenges, we ensured the safety of field workers by providing complete personal protective equipment and regular COVID-19 testing. Albeit with delay, we maintained the planned interval time between TORS application and ADDs services by overlapping the intervention cycles instead of having them in a sequential scheme. CE activities continued remotely through several channels (e.g., phone calls and text messages). Sustained efforts of the management team, significant involvement of the Malaysian Ministry of Health and a quick and smart adaptation of the trial organisation according to the pandemic situation were the main factors that allowed the successful continuation of our research.

Trial registration

Trial registration number: ISRCTN-81915073. Date of registration: 17/04/2020, 'Retrospectively registered'.

Experimental evolution supports the potential of neonicotinoid-pyrethroid combination for managing insecticide resistance in malaria vectors

The introduction of neonicotinoids for managing insecticide resistance in mosquitoes is of high interest as they interact with a biochemical target not previously used in public health. In this concern, Bayer developed a combination of the neonicotinoid clothianidin and the pyrethroid deltamethrin (brand name Fludora Fusion) as a new vector control tool. Although this combination proved to be efficient against pyrethroid-resistant mosquitoes, its ability to prevent the selection of pyrethroid and neonicotinoid resistance alleles was not investigated. In this context, the objective of this work was to study the dynamics and the molecular mechanisms of resistance of An. gambiae to the separated or combined components of this combination. A field-derived An. gambiae line carrying resistance alleles to multiple insecticides at low frequencies was used as a starting for 33 successive generations of controlled selection. Resistance levels to each insecticide and target site mutation frequencies were monitored throughout the selection process. Cross resistance to other public health insecticides were also investigated. RNA-seq was used to compare gene transcription variations and polymorphisms across all lines. This study confirmed the potential of this insecticide combination to impair the selection of resistance as compared to its two separated components. Deltamethrin selection led to the rapid enrichment of the kdr L1014F target-site mutation. Clothianidin selection led to the over-transcription of multiple cytochrome P450s including some showing high homology with those conferring neonicotinoid resistance in other insects. A strong selection signature associated with clothianidin selection was also observed on a P450 gene cluster previously associated with resistance. Within this cluster, the gene CYP6M1 showed the highest selection signature together with a transcription profile supporting a role in clothianidin resistance. Modelling the impact of point mutations selected by clothianidin on CYP6M1 protein structure showed that selection retained a protein variant with a modified active site potentially enhancing clothianidin metabolism. In the context of the recent deployment of neonicotinoids for mosquito control and their frequent usage in agriculture, the present study highlights the benefit of combining them with other insecticides for preventing the selection of resistance and sustaining vector control activities.

P–116 A 9-year monocentric retrospective analysis of glutaraldehyde-fixed and semithin section of testicular biopsies and TESE in azoospermic patients

Study question

What is the outcome of testicular sperm extraction (TESE) after microinjection of frozen–thawed sperm and the correlation with histological analysis in azoospermic patients?

Summary answer

In our cohort of 240 azoospermic patients, sperm could be retrieved in 167 patients (69.6%).

What is known already

Testicular biopsy is a crucial assessment in reproductive practice with diagnostic and prognostic importance for ICSI. Divers histological procedures are used throughout the centres. There is increasing need to accurately analyse histological biopsies in order to characterise different type of spermatogenic failure and allows data storage of value in clinical practice and research. Compared with Bouin’s and formalin, glutaraldehyde fixed and semithin section of testicular biopsies have the advantage of yielding not only good cellular morphology but also it allows the possibility of performing electron microscopy.

Study design, size, duration

This is a monocentric retrospective study of TESE practice in azoospermic patients in Strasbourg University Hospital from February 2011 to December 2019.

Participants/materials, setting, methods

A total of 240 azoospermic patients underwent TESE followed by sperm cryopreservation when sperm were present and data of histological analysis and clinical outcome of ICSI were analysed. The analysis include initial hormonal status, type of azoospermia, body max index, classification of histological findings, freezing rate and outcome of ICSI-IVF procedure.

Main results and the role of chance

The mean age of 240 patients was 34.5 years. Out of all patients, 42% were diagnosed with obstructive azoospermia (OA) and 58% patients with non-obstructive azoospermia (NOA). There was no correlation of sperm retrieval with the body mass index. Overall, sperm could be retrieved in 69.6% patients. Spermatozoa were always successfully recovered in patients with normal testicular histological findings, 41.7% patients (n 100). Histological analysis revealed a Sertoli cell-only (SCO) syndrome in 27.5% cases (n 66), hypospermatogenesis in 14.2% (n 34), germ cell arrest in 7.9 (n 19) and mixed pattern in 8.3% (n 20).

In patients with serum FSH concentrations >12 IU/l, 46% of patients (n 42) sperm were present at TESE. In patients with no sperm retrieval, 31.5% had normal FSH levels. Out of all men with elevated FSH, 63% had SCO pattern, 4% germ cell arrest, 21% hypospermatogenesis and 12% mixt patterns. In the group of patients with no sperm retrieved at TESE, histological analysis showed SCO in 69.9% cases, germ cell arrest in 15% and hypospermatogenesis in 9.6% of cases. Out of 167 patients with TESE and sperm cryopreservation, 126 patients undergone ICSI-IVF procedure and 80 babies were born.

Limitations, reasons for caution

This study is a retrospective analysis in a single centre. The cohort was not compared with groups of patients with different histological and fixation techniques.

Wider implications of the findings: Accurate histological diagnosis is a prerequisite for research and clinical data collection and open the possibilities to include patients with NOA in subsequent detailed genetic screen.

Trial registration number

NA

Measuring the effectiveness of integrated vector management with targeted outdoor residual spraying and autodissemination devices on the incidence of dengue in urban Malaysia in the iDEM trial (intervention for Dengue Epidemiology in Malaysia): study protocol for a cluster randomized controlled trial

Background

In common with many South East Asian countries, Malaysia is endemic for dengue. Dengue control in Malaysia is currently based on reactive vector management within 24 h of a dengue case being reported. Preventive rather than reactive vector control approaches, with combined interventions, are expected to improve the cost-effectiveness of dengue control programs. The principal objective of this cluster randomized controlled trial is to quantify the effectiveness of a preventive integrated vector management (IVM) strategy on the incidence of dengue as compared to routine vector control efforts.

Methods

The trial is conducted in randomly allocated clusters of low- and medium-cost housing located in the Federal Territory of Kuala Lumpur and Putrajaya. The IVM approach combines: targeted outdoor residual spraying with K-Othrine Polyzone, deployment of mosquito traps as auto-dissemination devices, and community engagement activities. The trial includes 300 clusters randomly allocated in a 1:1 ratio. The clusters receive either the preventive IVM in addition to the routine vector control activities or the routine vector control activities only. Epidemiological data from monthly confirmed dengue cases during the study period will be obtained from the Vector Borne Disease Sector, Malaysian Ministry of Health e-Dengue surveillance system. Entomological surveillance data will be collected in 12 clusters randomly selected from each arm.

To measure the effectiveness of the IVM approach on dengue incidence, a negative binomial regression model will be used to compare the incidence between control and intervention clusters. To quantify the effect of the interventions on the main entomological outcome, ovitrap index, a modified ordinary least squares regression model using a robust standard error estimator will be used.

Discussion

Considering the ongoing expansion of dengue burden in Malaysia, setting up proactive control strategies is critical. Despite some limitations of the trial such as the use of passive surveillance to identify cases, the results will be informative for a better understanding of effectiveness of proactive IVM approach in the control of dengue. Evidence from this trial may help justify investment in preventive IVM approaches as preferred to reactive case management strategies.

Trial registration

ISRCTN ISRCTN81915073. Retrospectively registered on 17 April 2020.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-021-05298-2.

A preliminary study of cerebral blood flow, aging and dementia in people with Down syndrome

BACKGROUND

People with Down syndrome (DS) develop Alzheimer's disease (AD) at an earlier age of onset than those with sporadic AD. AD neuropathology is typically present in DS by 40 years of age with an onset of dementia approximately 10 years later. This early onset is due to the overexpression of amyloid precursor protein from the third copy of chromosome 21. Cerebrovascular neuropathology is thought to contribute in 40-60% of cases sporadic AD. However, the vascular contribution to dementia in people with DS has been relatively unexplored. We hypothesised that vascular perfusion is compromised in older adults with DS relative to younger individuals and is further exacerbated in those with dementia.

METHOD

Cerebral blood flow (CBF) was measured using pulsed arterial spin labelling in 35 cognitively characterised adults with DS (26-65 years). DS participants were also compared with 15 control subjects without DS or dementia (26-65 years). Linear regression evaluated the difference in CBF across groups and diagnosis along with assessing the association between CBF and cognitive measures within the DS cohort.

RESULTS

Cerebral blood flow was significantly lower among DS participants with probable AD compared with controls (P = 0.02) and DS participants with no dementia (P = 0.01). Within the DS cohort, CBF was significantly associated with the Severe Impairment Battery (SIB) measure and the Dementia Questionnaire for People with Learning Disabilities (DLD) rating (F_3,25  = 5.13; P = 0.007). Both the SIB (β = 0.74; t = 2.71; P = 0.01) and DLD (β = -0.96; t = -3.87; P < 0.001) indicated greater impairment as global CBF decreased. Age was significantly associated with CBF among participants with DS. There was a non-linear effect of age, whereby CBF declined more rapidly after 45 years of age.

CONCLUSIONS

This preliminary study of CBF in DS indicates that cerebrovascular pathology may be a significant contributor to dementia in DS. CBF was associated with diagnosis, cognition and age. Notably, CBF decreases at a greater rate after age 45 and may represent a significant prodromal event in AD progression.

Targeted outdoor residual spraying, autodissemination devices and their combination against Aedes mosquitoes: field implementation in a Malaysian urban setting

Currently, dengue control relies largely on reactive vector control programmes. Proactive vector-control using a rational, well-balanced integrated vector management approach may prove more successful for dengue control. As part of the development of a cluster randomized controlled epidemiological trial, a study was conducted in Johor Bahru, Malaysia. The study included one control site (three buildings) and three intervention sites which were treated as follows: targeted outdoor residual spraying only (TORS site, two buildings); deployment of autodissemination devices only (ADD site, four buildings); and the previous two treatments combined (TORS + ADD site, three buildings). The primary entomological measurement was per cent of positive ovitraps-ovitrap index (OI). The effect of each intervention on OI was analyzed by a modified ordinary least squares regression model. Relative to the control site, the TORS and ADD sites showed a reduction in the Aedes OI (-6.5%, P = 0.04 and -8.3%, P = 0.10, respectively). Analysis by species showed that, relative to control, the Ae. aegypti OI was lower in ADD (-8.9%, P = 0.03) and in TORS (-10.4%, P = 0.02). No such effect was evident in the TORS + ADD site. The present study provides insights into the methods to be used for the main trial. The combination of multiple insecticides with different modes of action in one package is innovative, although we could not demonstrate the additive effect of TORS + ADD. Further work is required to strengthen our understanding of how these interventions impact dengue vector populations and dengue transmission.

ACCIDENTAL FINDING OF SYNCHRONOUS BILATERAL DUCTAL CARCINOMA IN SITU IN A YOUNG MAN REFERRED TO MASTECTOMY DUE TO GYNECOMASTIA - AND WHAT IF LIPOSUCTION HAVE BEEN USED? CASE REPORT

Breast male cancer is a rare condition. We report a case of a synchronous bilateral ductal carcinoma in situ (DCIS) which developed in a 26-year-old man with long-standing gynecomastia. He underwent bilateral subcutaneous mastectomy. Histology revealed bilateral pure DCIS. There was no identifiable causative factor for the development of bilateral DCIS, and there was no family history of the disease. No other treatment was required, and after 18 months there were no signs of local recurrence. This case highlights the importance of staying vigilant regarding the presence of malignancy in normally benign conditions. Liposuction has become a very useful technique for gynecomastia correction, however, there is a risk of dissemination of an unknown malignant tumor. In atypical cases, en bloc surgical excision should be performed.

Thyroid FNAC: Causes of false-positive results

In this paper, we aim to focus on false positive results in the evaluation of thyroid aspirations, covering cystic, inflammatory, follicular and oncocytic lesions, papillary carcinoma, and medullary carcinoma of thyroid. The recently described entity noninvasive follicular thyroid neoplasm with papillary-like nuclear features is also discussed detailing the impact of its introduction on the sensitivity and specificity of thyroid FNA, as well as the use of molecular tests for diagnostics. Medicolegal issues in relation to current practice in English law are also described.

Standardisierter Computer-basiert-organisierter Report des EEG (SCORE) – Eine strukturierende Form der EEG-Befundung

Eine 2013 von der „International Federation of Clinical Neurophysiology“ gegründete Taskforce hat eine international konsensfähige EEG-Terminologie entwickelt. Im Folgenden soll das Resultat – die 2. Version des Standardized Computer-based Organized Reporting of EEG (SCORE) - vorgestellt werden. Die Terminologie wurde im Rahmen eines Softwarepaketes (SCORE-EEG) in der klinischen Praxis an über 12.000 EEGs getestet. Die Auswahl der Begriffe ist kontextabhängig: die initiale Auswahl bestimmt, welche weiteren Auswahlmöglichkeiten zur Verfügung stehen. Im Verlauf wird automatisch ein Befund erstellt und dessen Einzelmerkmale in eine Datenbank eingespeist. SCORE verfügt über Module spezifisch für die Befundung epileptischer Anfälle, sowie charakteristischer neonataler und intensivmedizinische EEG-Merkmale. SCORE ist nicht nur ein nützliches Werkzeug im ambulanten, klinischen und wissenschaftlichen Setting, es erleichtert auch Qualitätssicherung, Datenaustausch und die EEG-Aus und Weiterbildung.

Laparoscopic adjustable gastric banding in adolescents with severe obesity: Psychological aspects, decision makers of surgery, and 2-year outcomes. A case series

BACKGROUND

The results of medical treatment of severe obesity in the adolescent population (balanced diet and physical activity) are often unsatisfactory, and bariatric surgery is questioned. The psychological determinants for requesting bariatric surgery in these adolescents are unclear. The objective of this study was to report the psychiatric and psychological aspects as well as the determinants of the medical decision for surgery in a cohort of obese adolescents requesting bariatric surgery by laparoscopic adjustable gastric banding.

METHODS

Thirty-five adolescents (12.3-17.7 years of age), were recruited from January 2007 to December 2012. Semistructured interviews were conducted.

RESULTS

Fifty-four percent of the adolescents had a psychiatric history and 85% had psychiatric comorbidities. In adolescents undergoing surgery, excess weight loss was 46% after 1 year and 51% after 2years. For patients not receiving surgery, excess weight loss was 0.43% after 1 year (P=0.001). Compliance with medical treatment was the only significant element contributing to the decision to perform surgery. Results in terms of satisfaction and perception 1 and 2years after surgery were encouraging.

CONCLUSION

Bariatric surgery is feasible in young patients and produces good results in terms of excess weight loss. We argue that compliance with medical treatment is probably one of the most important elements for making the decision to perform bariatric surgery and in excess weight loss after surgery. We probably need to focus on the compliance of young patients and evaluate how this can be improved.

Morphological features that can predict BRAFV600E -mutated carcinoma in paediatric thyroid cytology

OBJECTIVE

BRAF^V600E represents the most common diagnostic marker in papillary thyroid carcinoma (PTC). A few papers have demonstrated the correlation between BRAF^V600E and specific morphological findings on PTCs in the adult population. This is the first reported series investigating cytological morphological parameters in paediatric thyroid carcinoma.

METHODS

One hundred and nineteen paediatric samples (56 male and 63 female patients), diagnosed in the period between April 2013 and July 2015, were enrolled in the study. Fifteen patients with inadequate results were excluded. Cytological cases were processed with liquid-based cytology (LBC). BRAF^V600E and immunocytochemistry for the VE1 antibody were performed on LBC.

RESULTS

The diagnostic series included 10 mutated and 94 wild-type (WT) cases. Twenty two percent surgical samples showed 96% cytohistological concordance. The morphological analysis revealed plump cells (abundant eosinophilic cytoplasm and PTC nuclei) in all 10 mutated cases with only four cases showing a focal (less than 20% of the cells) plump component. None of the WT showed plump cells. A sickle nuclear shape was seen only in the mutated cases. VE1 yielded 100% positivity on mutated cases with three cytohistological discrepancies.

CONCLUSIONS

The BRAF^V600E mutation is also seen in paediatric cytology and the morphological features showed a high accuracy as both predictive mutational parameters and a helpful aid in management mainly of the aggressive BRAF^V600E mutated carcinomas.

Persistent order due to transiently enhanced nesting in an electronically excited charge density wave

Non-equilibrium conditions may lead to novel properties of materials with broken symmetry ground states not accessible in equilibrium as vividly demonstrated by non-linearly driven mid-infrared active phonon excitation. Potential energy surfaces of electronically excited states also allow to direct nuclear motion, but relaxation of the excess energy typically excites fluctuations leading to a reduced or even vanishing order parameter as characterized by an electronic energy gap. Here, using femtosecond time- and angle-resolved photoemission spectroscopy, we demonstrate a tendency towards transient stabilization of a charge density wave after near-infrared excitation, counteracting the suppression of order in the non-equilibrium state. Analysis of the dynamic electronic structure reveals a remaining energy gap in a highly excited transient state. Our observation can be explained by a competition between fluctuations in the electronically excited state, which tend to reduce order, and transiently enhanced Fermi surface nesting stabilizing the order.

Whilst excited electronic states may exhibit unique non-equilibrium behavior, order is inhibited by fluctuations. Here, the authors use femtosecond photoemission spectroscopy to demonstrate transient stabilization of charge density wave order in rare earth tritellurides after near-infrared excitation.

Guidelines for time-to-event end point definitions in breast cancer trials: results of the DATECAN initiative (Definition for the Assessment of Time-to-event Endpoints in CANcer trials)†

BACKGROUND

Using surrogate end points for overall survival, such as disease-free survival, is increasingly common in randomized controlled trials. However, the definitions of several of these time-to-event (TTE) end points are imprecisely which limits interpretation and cross-trial comparisons. The estimation of treatment effects may be directly affected by the definitions of end points. The DATECAN initiative (Definition for the Assessment of Time-to-event Endpoints in CANcer trials) aims to provide recommendations for definitions of TTE end points. We report guidelines for randomized cancer clinical trials (RCTs) in breast cancer.

PATIENTS AND METHODS

A literature review was carried out to identify TTE end points (primary or secondary) reported in publications of randomized trials or guidelines. An international multidisciplinary panel of experts proposed recommendations for the definitions of these end points based on a validated consensus method that formalize the degree of agreement among experts.

RESULTS

Recommended guidelines for the definitions of TTE end points commonly used in RCTs for breast cancer are provided for non-metastatic and metastatic settings.

CONCLUSION

The use of standardized definitions should facilitate comparisons of trial results and improve the quality of trial design and reporting. These guidelines could be of particular interest to those involved in the design, conducting, reporting, or assessment of RCT.

Metastatic breast cancer: mechanisms and opportunities for cytology

Despite significant advances in diagnosis, surgical techniques, general patient care, and local and systemic adjuvant therapies, metastatic disease remains the most critical condition limiting the survival of patients with breast cancer. Therefore, the development of effective treatment against late-arising metastasis has become the centre of clinical attention and is one of the current challenges in cancer research. A deeper understanding of the metastatic cascade is fundamental, and the need for repetitive tumour assessments for the evaluation of tumour evolution is a relatively new practice in routine medical care. As such, fine needle aspiration cytology (FNAC) is ideally placed to monitor biological changes in metastasis that may affect treatment and response. As FNAC is a minimally invasive method, it can be performed repeatedly with relatively little trauma, and selective ancillary tests can be applied to FNAC specimens, including for tumour whose primary nature is known. Herein, we review how the linear and parallel models explain metastatic dissemination, thus influencing therapeutic and clinical decisions, and how cytology, together with immunocytochemistry and molecular analysis, can be a tool for routine clinical practice and clinical trials aimed at metastatic disease with a special emphasis on breast cancer.

Chemosaturation with percutaneous hepatic perfusions of melphalan for hepatic metastases: experience from two European centers

PURPOSE

Chemosaturation with percutaneous hepatic perfusion (PHP; Hepatic CHEMOSAT(®) Delivery System; Delcath Systems Inc, USA) is a minimally invasive, repeatable regional therapy for unresectable hepatic metastases. It uses a system of catheters and filters to isolate hepatic venous blood from the systemic circulation, allowing delivery of high-dose chemotherapy to the hepatic artery. Effluent hepatic venous blood is filtered before being returned to the systemic circulation, thereby reducing exposure to chemotherapy. We describe our experiences with chemosaturation-PHP at 2 European centers.

MATERIALS AND METHODS

14 patients presented unresectable hepatic metastases from solid tumors; 13 received 1 - 3 sessions of chemosaturation-PHP. Melphalan 2.0 (n = 1) or 3.0 (n = 12) mg/kg was given as a 30-minute infusion into the hepatic artery. 12 patients were evaluable for tumor response.

RESULTS

One complete (cholangiocarcinoma, n = 1) and 6 partial responses (ocular, n = 3 or cutaneous melanoma, n = 3) were observed, 5 patients had stable disease (ocular melanoma, n = 3; breast cancer, n = 1; gastric cancer, n = 1). Mild to moderate filter-related toxicity (i. e. thrombocytopenia, anemia) was observed immediately post-procedure. Grade 3/4 melphalan-related pancytopenia developed after 1 - 2 weeks. All hematological events were managed effectively with transfusions and/or other supportive measures. The new high-efficiency filter showed milder toxicity and faster recovery. In one case, chemosaturation-PHP was abandoned prematurely due to heparin-induced vaginal bleeding, and one patient died due to retroperitoneal hemorrhage from heparin anti-coagulation.

CONCLUSION

Chemosaturation-PHP for non-resectable liver metastases is a feasible treatment option when performed by an experienced multi-disciplinary team. It may be a promising regional therapy for patients with no effective treatment options.

Pushing the limits of in vivo diffusion MRI for the Human Connectome Project

Perhaps more than any other "-omics" endeavor, the accuracy and level of detail obtained from mapping the major connection pathways in the living human brain with diffusion MRI depend on the capabilities of the imaging technology used. The current tools are remarkable; allowing the formation of an "image" of the water diffusion probability distribution in regions of complex crossing fibers at each of half a million voxels in the brain. Nonetheless our ability to map the connection pathways is limited by the image sensitivity and resolution, and also the contrast and resolution in encoding of the diffusion probability distribution. The goal of our Human Connectome Project (HCP) is to address these limiting factors by re-engineering the scanner from the ground up to optimize the high b-value, high angular resolution diffusion imaging needed for sensitive and accurate mapping of the brain's structural connections. Our efforts were directed based on the relative contributions of each scanner component. The gradient subsection was a major focus since gradient amplitude is central to determining the diffusion contrast, the amount of T2 signal loss, and the blurring of the water PDF over the course of the diffusion time. By implementing a novel 4-port drive geometry and optimizing size and linearity for the brain, we demonstrate a whole-body sized scanner with G(max) = 300 mT/m on each axis capable of the sustained duty cycle needed for diffusion imaging. The system is capable of slewing the gradient at a rate of 200 T/m/s as needed for the EPI image encoding. In order to enhance the efficiency of the diffusion sequence we implemented a FOV shifting approach to Simultaneous MultiSlice (SMS) EPI capable of unaliasing 3 slices excited simultaneously with a modest g-factor penalty allowing us to diffusion encode whole brain volumes with low TR and TE. Finally we combine the multi-slice approach with a compressive sampling reconstruction to sufficiently undersample q-space to achieve a DSI scan in less than 5 min. To augment this accelerated imaging approach we developed a 64-channel, tight-fitting brain array coil and show its performance benefit compared to a commercial 32-channel coil at all locations in the brain for these accelerated acquisitions. The technical challenges of developing the over-all system are discussed as well as results from SNR comparisons, ODF metrics and fiber tracking comparisons. The ultra-high gradients yielded substantial and immediate gains in the sensitivity through reduction of TE and improved signal detection and increased efficiency of the DSI or HARDI acquisition, accuracy and resolution of diffusion tractography, as defined by identification of known structure and fiber crossing.

Multinational study of oestrogen and progesterone receptor immunocytochemistry on breast carcinoma fine needle aspirates

OBJECTIVES

To collect data on the variability of immunocytochemical (ICC) procedures used to detect oestrogen/progesterone receptors (ER/PR) on cytological material; to test the reproducibility of results; and to identify the crucial points in the ICC procedures that affect the result.

METHODS

Ten laboratories from eight countries participated in a two-part study. In the first part, one of the participants (the coordinator) prepared and distributed cytospins from a fine needle aspirate of a primary breast carcinoma. Laboratories performed ICC staining for ER/PR according to their own methods on the test slides and in-house positive controls. Slides were returned to the coordinator together with information on the preparation of positive control slides and the ICC methodology used. In the second part, obligatory methods of fixation and antigen retrieval were specified. Evaluation of results included grading the number of positive cells, staining intensity, background staining, cytoplasmic staining, sample condition and cellularity. Participants evaluated their own results, which were subsequently evaluated by the coordinator.

RESULTS

There was great variability in the preparation of slides for in-house controls and ICC methodology. The outcome of ICC staining of in-house control slides was excellent in two laboratories, adequate in three, sub-optimal in four and inadequate in one. Only six obtained a positive reaction on the test slides and not all were of a high quality. Results of the second run were greatly improved in terms of cellularity of in-house positive control slides, and scores for the percentage of stained cells and staining intensity of control and test slides. Cytospins and monolayer (ThinPrep(®)) preparations were superior to direct smears; methods of fixation and antigen retrieval were the key points in the staining process.

CONCLUSIONS

Our experience points to the need for guidelines for hormonal receptor determination and external quality control on cytological material, in order for cytological methods to be used in routine clinical practice with a suitable degree of confidence.