A modality-specific somatosensory evoked potential test protocol for clinical evaluation: A feasibility study

ObjectiveWe aimed to establish an objective neurophysiological test protocol that can be used to assess the somatosensory nervous system.MethodsIn order to assess most fiber subtypes of the somatosensory nervous system, repetitive stimuli of seven different modalities (touch, vibration, pinprick, cold, contact heat, laser, and warmth) were synchronized with the electroencephalogram (EEG) and applied on the cheek and dorsum of the hand and dorsum of the foot in 21 healthy subjects and three polyneuropathy (PNP) patients. Latencies and amplitudes of the modalities were assessed and compared. Patients received quantitative sensory testing (QST) as reference.ResultsWe found reproducible evoked potentials recordings for touch, vibration, pinprick, contact-heat, and laser stimuli. The recording of warm-evoked potentials was challenging in young healthy subjects and not applicable in patients. Latencies were shortest within Aβ-fiber-mediated signals and longest within C-fibers. The test protocol detected function loss within the Aβ-fiber and Aδ-fiber-range in PNP patients. This function loss corresponded with QST findings.ConclusionIn this pilot study, we developed a neurophysiological test protocol that can specifically assess most of the somatosensory modalities. Despite technical challenges, initial patient data appear promising regarding a possible future clinical application.SignificanceEstablished and custom-made stimulators were combined to assess different fiber subtypes of the somatosensory nervous system using modality-specific evoked potentials.     

Molecular profiling of ctDNA in pancreatic cancer: Opportunities and challenges for clinical application

Pancreatic ductal adenocarcinoma (PDAC) is predicted to become the second leading cause of cancer-related mortality within the next decade, with limited effective treatment options and a dismal long-term prognosis for patients. Genomic profiling has not yet manifested clinical benefits for diagnosis, treatment or prognosis in PDAC, due to the lack of available tissues for sequencing and the confounding effects of low tumour cellularity in many biopsy specimens. Increasing focus is now turning to the use of minimally invasive liquid biopsies to enhance the characterisation of actionable PDAC tumour genomes. Circulating tumour DNA (ctDNA) is the most comprehensively studied liquid biopsy analyte in blood and can provide insight into the molecular profile and biological characteristics of individual PDAC tumours, in real-time and in advance of traditional imaging modalities. This can pave the way for identification of new therapeutic targets, novel risk variants and markers of tumour response, to supplement diagnostic screening and provide enhanced scrutiny in treatment stratification. In the roadmap towards the application of precision medicine for clinical management in PDAC, ctDNA analyses may serve a leading role in streamlining candidate biomarkers for clinical integration. In this review, we highlight recent developments in the use of ctDNA-based liquid biopsies for PDAC and provide new insights into the technical, analytical and biological challenges that must be overcome for this potential to be realised.     

Direct oral anticoagulants (DOACs) and neck of femur fractures: Standardising the perioperative management and time to surgery

Demographic projections for hip fragility fractures indicate a rising annual incidence by virtue of a multimorbid, ageing population with more noncommunicable diseases (NCDs). NCDs are characterised by slow progression and long duration ranging from ischaemic cardiovascular disease, cerebrovascular disease, diabetes, chronic obstructive pulmonary disease to various cancers. Management of this disease burden often involves commencing patients on oral anticoagulants to reduce the risk of thromboembolic events. The use of direct oral anticoagulants (DOACs) in clinical practice has increased due to their rapid onset of action, short half-life and predictable anticoagulant effects, without the need for routine monitoring. Safe and timely surgical intervention relies on reversal of anticoagulants. However, the lack of specific evidence-based guidelines for the perioperative management of patients on DOACs with hip fractures has proved challenging; in particular, the accessibility of DOAC-specific assays, justification of the cost-benefit ratio of targeted reversal agents and indications for neuraxial anaesthesia. This has led to potentially avoidable delays in surgical intervention. Following a literature review of the pharmacokinetic and pharmacodynamics of commonly used DOACs in our region including the role of surrogate markers, we propose a systematic, evidence-based guideline to the perioperative management of hip fractures DOACs. We believe this standardised protocol can be easily replicated between hospitals. We recommend that if patients are deemed suitable for a general anaesthesia, with satisfactory renal function, optimal surgical time should be 24 h following the last ingested dose of DOAC.     

Outcomes After Aortic Valve Replacement for Asymptomatic Severe Aortic Regurgitation and Normal Ejection Fraction

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Maximizing intelligence obtained from higher-order DNA mixtures from volume crime samples

ABSTRACT

This work collates data from the analysis of complex mixtures analysed in STRmix during routine no-suspect volume crime work. It interrogates the upload rate for these types of mixtures and which component of the profile has been able to be interpreted for upload. The number of profiles giving multiple uploads and the amount of replicate PCR analysis has been collated.     

TLR9在不同胎龄新生儿脐血中的表达变化

目的 通过观察早产儿不同胎龄Toll样受体9（TLR9）的表达，探讨早产儿免疫功能低下的机制。方法 采集2010年7月至2014年6月在上海市嘉定区妇幼保健院产科出生的活产新生儿的脐血229份，按胎龄分为4组，28~31周组，31~34周组，34~37周组，≥37周组，采用流式细胞术和实时荧光定量PCR方法，分别检测其TLR9的蛋白和mRNA表达情况，了解其与胎龄之间的关系，并分析mRNA和蛋白表达间的相关性。结果 TLR9阳性细胞率在28~31周组，31~34周组，34~37周组，≥37周组分别为（15.93±6.23）%，（11.63±6.70）%，（13.66±6.88）%，（20.51±12.06）%；其在胎龄28~31周较高，至31~34周逐渐下降至最低，两组差异有统计学意义（P<0.05）；34~37周后TLR9阳性细胞率表达逐渐升高，至≥37周达最高，两胎龄组比较，差异具有统计学意义（P<0.05）。31~37周间新生儿脐血TLR9阳性细胞率与胎龄呈正相关（r=0.273，P=0.006）。TLR9 mRNA表达在28~31周组，31~34周组，34~37周组，≥37周组分别为（4.95±3.44）%，（8.89±8.49）%，（13.91±10.92）%，（7.19±7.11）%；其在28~36周逐渐升高，与胎龄呈正相关（r=0.355，P< 0.001）。≥37周TLR9 mRNA表达量下降，该值虽高于28~31周，但差异无统计学意义（P>0.05）。相关性分析表明，同胎龄时期同样本新生儿的TLR9 mRNA和TLR9阳性细胞率之间存在负相关（r=-0.227，P=0.011）。结论 TLR9阳性细胞率和TLR9 mRNA表达在不同胎龄组新生儿间有差异，TLR9阳性细胞率表达在31~37周间随着胎龄的增加而增加，TLR9 mRNA在28~36周间随着胎龄的增加而增加。     

Recent advances in preclinical in vitro approaches towards quantitative prediction of hepatic clearance and drug-drug interactions involving organic anion transporting polypeptide (OATP) 1B transporters

Hepatic uptake mediated by organic anion transporting polypeptide (OATP) 1B1 and 1B3 can serve as a major elimination pathway for various anionic drugs and as a site of drug-drug interactions (DDIs). This article provides an overview of the in vitro approaches used to predict human hepatic clearance (CL_h) and the risk of DDIs involving OATP1Bs. On the basis of the so-called extended clearance concept, in vitro–in vivo extrapolation methods using human hepatocytes as in vitro systems have been used to predict the CL_h involving OATP1B-mediated hepatic uptake. CL_h can be quantitatively predicted using human donor lots possessing adequate OATP1B activities. The contribution of OATP1Bs to hepatic uptake can be estimated by the relative activity factor, the relative expression factor, or selective inhibitor approaches, which offer generally consistent outcomes. In OATP1B1 inhibition assays, substantial substrate dependency was observed. The time-dependent inhibition of OATP1B1 was also noted and may be a mechanism underlying the in vitro–in vivo differences in the inhibition constant of cyclosporine A. Although it is still challenging to quantitatively predict CL_h and DDIs involving OATP1Bs from only preclinical data, understanding the utility and limitation of the current in vitro methods will pave the way for better prediction.