Wide-range soft anisotropic thermistor with a direct wireless radio frequency interface

Temperature sensors are one of the most fundamental sensors and are found in industrial, environmental, and biomedical applications. The traditional approach of reading the resistive response of Positive Temperature Coefficient thermistors at DC hindered their adoption as wide-range temperature sensors. Here, we present a large-area thermistor, based on a flexible and stretchable short carbon fibre incorporated Polydimethylsiloxane composite, enabled by a radio frequency sensing interface. The radio frequency readout overcomes the decades-old sensing range limit of thermistors. The composite exhibits a resistance sensitivity over 1000 °C-1, while maintaining stability against bending (20,000 cycles) and stretching (1000 cycles). Leveraging its large-area processing, the anisotropic composite is used as a substrate for sub-6 GHz radio frequency components, where the thermistor-based microwave resonators achieve a wide temperature sensing range (30 to 205 °C) compared to reported flexible temperature sensors, and high sensitivity (3.2 MHz/°C) compared to radio frequency temperature sensors. Wireless sensing is demonstrated using a microstrip patch antenna based on a thermistor substrate, and a battery-less radio frequency identification tag. This radio frequency-based sensor readout technique could enable functional materials to be directly integrated in wireless sensing applications.

Cobalt containing glass fibres and their synergistic effect on the HIF-1 pathway for wound healing applications

Introduction and Methods: Chronic wounds are a major healthcare problem, but their healing may be improved by developing biomaterials which can stimulate angiogenesis, e.g. by activating the Hypoxia Inducible Factor (HIF) pathway. Here, novel glass fibres were produced by laser spinning. The hypothesis was that silicate glass fibres that deliver cobalt ions will activate the HIF pathway and promote the expression of angiogenic genes. The glass composition was designed to biodegrade and release ions, but not form a hydroxyapatite layer in body fluid.

Results and Discussion: Dissolution studies demonstrated that hydroxyapatite did not form. When keratinocyte cells were exposed to conditioned media from the cobalt-containing glass fibres, significantly higher amounts of HIF-1α and Vascular Endothelial Growth Factor (VEGF) were measured compared to when the cells were exposed to media with equivalent amounts of cobalt chloride. This was attributed to a synergistic effect of the combination of cobalt and other therapeutic ions released from the glass. The effect was also much greater than the sum of HIF-1α and VEGF expression when the cells were cultured with cobalt ions and with dissolution products from the Co-free glass, and was proven to not be due to a rise in pH. The ability of the glass fibres to activate the HIF-1 pathway and promote VEGF expression shows the potential for their use in chronic wound dressings.

Genome Editing With TALEN, CRISPR-Cas9 and CRISPR-Cas12a in Combination With AAV6 Homology Donor Restores T Cell Function for XLP

X-linked lymphoproliferative disease is a rare inherited immune disorder, caused by mutations or deletions in the SH2D1A gene that encodes an intracellular adapter protein SAP (Slam-associated protein). SAP is essential for mediating several key immune processes and the immune system - T cells in particular - are dysregulated in its absence. Patients present with a spectrum of clinical manifestations, including haemophagocytic lymphohistiocytosis (HLH), dysgammaglobulinemia, lymphoma and autoimmunity. Treatment options are limited, and patients rarely survive to adulthood without an allogeneic haematopoietic stem cell transplant (HSCT). However, this procedure can have poor outcomes in the mismatched donor setting or in the presence of active HLH, leaving an unmet clinical need. Autologous haematopoeitic stem cell or T cell therapy may offer alternative treatment options, removing the need to find a suitable donor for HSCT and any risk of alloreactivity. SAP has a tightly controlled expression profile that a conventional lentiviral gene delivery platform may not be able to fully replicate. A gene editing approach could preserve more of the endogenous regulatory elements that govern SAP expression, potentially providing a more optimum therapy. Here, we assessed the ability of TALEN, CRISPR-Cas9 and CRISPR-Cas12a nucleases to drive targeted insertion of SAP cDNA at the first exon of the SH2D1A locus using an adeno-associated virus serotype 6 (AAV6)-based vector containing the donor template. All nuclease platforms were capable of high efficiency gene editing, which was optimised using a serum-free AAV6 transduction protocol. We show that T cells from XLP patients corrected by gene editing tools have restored physiological levels of SAP gene expression and restore SAP-dependent immune functions, indicating a new therapeutic opportunity for XLP patients.

SP10.1.9 Delay to Elective Colorectal Cancer Surgery and its Potential Implications: A Systematic Review and Meta-analysis

Aim

The ongoing Covid-19 pandemic has interrupted surgical treatment of colorectal cancer (CRC). This systematic review will assess literature concerning the risk of delay of elective surgery for CRC patients, focusing on overall survival (OS) and disease-free survival (DFS).

Methods

A systematic review was performed as per PRISMA guidelines (PROSPERO ID: CRD42020189158). Medline, EMBASE and Scopus were searched. Patients over 18 with a diagnosis of colon or rectal cancer who received elective surgery as primary treatment were included. Delay was defined as the period between CRC diagnosis and day of surgery. Metanalyses of the outcomes OS and DFS were conducted. Forest plots, funnel plots, tests of heterogeneity, and estimated Number Needed to Harm (NNHs) were produced.

Results

Of 3753 articles identified, seven met the inclusion criteria. Encompassing 314560 patients, three of the seven studies showed a delay to elective resection was associated with poorer OS or DFS. OS was assessed at a one-month delay, the HR for six datasets was 1.13 (95%CI 1.02-1.26, p = 0.020) and at three months the HR for three datasets was 1.57 (95%CI 1.16-2.12, p = 0.004). Estimated NNHs for a delay at one month and three months were 35 and 10 respectively. Delay was non-significantly negatively associated with DFS on metanalysis.

Conclusions

This review recommends elective surgery for CRC patients is not postponed longer than four weeks, as evidence suggests extended delays from diagnosis are associated with poorer outcomes. Focused research is essential so patient groups can be prioritized based on risk-factors for future pandemics.

732 Delay to Elective Colorectal Cancer Surgery and its Potential Implications During the Covid-19 Pandemic: A Systematic Review and Metanalysis

Aim

The ongoing Covid-19 pandemic has interrupted the surgical treatment of colorectal cancer (CRC). This systematic review will assess literature concerning the risk of delay of elective surgery for CRC patients, focusing on overall survival (OS) and disease-free survival (DFS).

Method

A systematic review was performed as per PRISMA guidelines (PROSPERO ID: CRD42020189158). Medline, EMBASE and Scopus were searched. Delay to elective surgery was defined as the period between CRC diagnosis and the day of surgery. Metanalyses of the outcome’s OS and DFS were conducted. Forest plots, funnel plots, and tests of heterogeneity were produced. An estimated Number Needed to Harm (NNH) was calculated for statistically significant pooled Hazard Ratios (HRs).

Results

Of 3753 articles identified, seven met the inclusion criteria. Encompassing 314560 patients, three of the seven studies showed that a delay to elective resection is associated with poorer OS or DFS. OS was assessed at a one-month delay, the HR for six datasets was 1.13 (95%CI 1.02-1.26, p = 0.020) and at three months the pooled HR for three datasets was 1.57 (95%CI 1.16-2.12, p = 0.004). Estimated NNHs for a delay at one month and three months were 35 and 10 respectively. Delay was non-significantly negatively associated with DFS on meta-analysis.

Conclusions

This review recommends that elective surgery for CRC patients is not postponed, as evidence suggests delays from diagnosis are associated with poorer outcomes. Focused research is essential so that patient groups can be prioritized based on risk factors for future pandemics.

Material Cues as Potent Regulators of Epigenetics and Stem Cell Function

Biophysical signals act as potent regulators of stem cell function, lineage commitment, and epigenetic status. In recent years, synthetic biomaterials have been used to study a wide range of outside-in signaling events, and it is now well appreciated that material cues modulate the epigenome. Here, we review the role of extracellular signals in guiding stem cell behavior via epigenetic regulation, and we stress the role of physicochemical material properties as an often-overlooked modulator of intracellular signaling. We also highlight promising new research tools for ongoing interrogation of the stem cell-material interface.

Introduction of Portable Computed Tomography Scanners, in the Treatment of Acute Stroke Patients via Telemedicine in Remote Communities

Background

Thrombolysis is an established treatment in selected patients who present early to hospital after symptoms of acute ischaemic stroke. Treatment can only be offered after the patient has been assessed by highly trained physicians and imaging studies have ruled out a brain haemorrhage. This limits the wider availability of thrombolysis to patients in remote communities, especially in countries with limited resources. There has been considerable success with the use of TeleStroke to overcome such barriers. TeleStroke is feasible in remote hospitals provided there is an available computed tomography scanner, a fundamental prerequisite in the assessment of acute stroke and thrombolysis. This is a luxury not widely available, especially in remote sites. Recently, Neurologica introduced a portable computed tomography scanner that can be operated after minimal training.

Methods

We report our preliminary experience with the portable computed tomography scanner in a remote community where Telemedicine was successfully used to evaluate and treat patients presenting with symptoms suggestive of an acute ischaemic stroke. The University of Alberta Hospital in Edmonton, Canada was the ‘hub’ site and Wainwright Community Hospital was the ‘spoke’ site.

Results

Over a 3-month period, 18 patients were evaluated in the emergency department of the remote hospital where the referring physician felt that symptoms indicated potential for thrombolysis. All patients were evaluated remotely by a stroke neurologist in a TeleStroke service situated 207 km from the rural site. After clinical examination, cranial computed tomography scans were obtained with the portable scanner and evaluated by the stroke neurologist. In three patients, thrombolysis was not offered because the computed tomography showed evidence of brain haemorrhage: two intracerebral haemorrhage and one subarachnoid haemorrhage. Three patients meeting the standard criteria received thrombolysis within 4·5 h from onset of symptoms. There was a significant improvement in two patients. One patient did not make a good recovery. Repeat computed tomography scans showed a small haemorrhagic transformation in one patient. In the remaining 12 subjects, symptoms improved rapidly, were outside the window for thrombolysis, or were not consistent with an acute ischaemic stroke.

Interpretations

Our preliminary study shows that the portable scanner can be used successfully in the evaluation of patients in remote regions that are not within timely reach of stroke experts or do not have available conventional imaging with computed tomography scans. Telemedicine, in combination with the use of portable scanners, offers hope to a large remote population base that would otherwise not have access to appropriate acute stroke treatment.

A stretch reflex in extraocular muscles of species purportedly lacking muscle spindles

It is generally assumed that proprioceptive feedback plays a crucial role in limb posture and movement. However, the role of afferent signals from extraocular muscles (EOM) in the control of eye movement has been a matter of continuous debate. These muscles have atypical sensory receptors in several species and it has been proposed that they are not supported by stretch reflexes. We recorded electromyographic activity of EOM during passive rotations of the eye in sedated rats and squirrel monkeys and observed typical stretch reflexes in these muscles. Results suggest that there is a similarity in the reflexive control of limb and eye movement, despite substantial differences in their biomechanics and sensory receptors. Like in some limb skeletal muscles, the stretch reflex in EOM in the investigated species might be mediated by other length-sensitive receptors, rather than muscle spindles.

Individualized exercise program for the treatment of severe fatigue in patients after allogeneic hematopoietic stem-cell transplant: a pilot study

Chronic cancer-related fatigue in otherwise asymptomatic post-allogeneic hematopoietic stem cell transplant (HSCT) patients is common and debilitating. This pilot study investigated whether patients with no clinical or psychological abnormalities but severe fatigue would respond to an individually adapted aerobic exercise program. Participants were 12 patients (eight male, and four female patients), median age 47 years and 41 months post-HSCT with a variety of hematopoietic cancer diagnoses. All underwent a 12-week individualized mild aerobic exercise program, preceded by a 4-week introduction and baseline testing phase. Psychological measures included fatigue, mood and depression. Exercise-related physiological outcomes included power output at ventilatory threshold 2 (VT2) and associated changes in stroke volume, heart rate, blood lactate concentration and ratings of perceived exertion. Patients were assessed for fatigue before, immediately after and at 3, 6, 9 and 12 months post-program. Significant improvements were found on both measures of fatigue (both P<0.001), with a very large effect size of 1.82 on the The Functional Assessment of Cancer Therapy - Fatigue Module, which were maintained over the follow-up period. Exercise testing revealed a mean increase (P<0.001) of 28% in power output at VT2 with an increase (P<0.001) in stroke volume and a decrease (P<0.001) in heart rate, blood lactate and perceived exertion at pre-intervention VT2 power output.

Transformation of human osteoblast cells to the tumorigenic phenotype by depleted uranium-uranyl chloride

Depleted uranium (DU) is a dense heavy metal used primarily in military applications. Although the health effects of occupational uranium exposure are well known, limited data exist regarding the long-term health effects of internalized DU in humans. We established an in vitro cellular model to study DU exposure. Microdosimetric assessment, determined using a Monte Carlo computer simulation based on measured intracellular and extracellular uranium levels, showed that few (0.0014%) cell nuclei were hit by alpha particles. We report the ability of DU-uranyl chloride to transform immortalized human osteoblastic cells (HOS) to the tumorigenic phenotype. DU-uranyl chloride-transformants are characterized by anchorage-independent growth, tumor formation in nude mice, expression of high levels of the k-ras oncogene, reduced production of the Rb tumor-suppressor protein, and elevated levels of sister chromatid exchanges per cell. DU-uranyl chloride treatment resulted in a 9.6 (+/- 2.8)-fold increase in transformation frequency compared to untreated cells. In comparison, nickel sulfate resulted in a 7.1 (+/- 2.1)-fold increase in transformation frequency. This is the first report showing that a DU compound caused human cell transformation to the neoplastic phenotype. Although additional studies are needed to determine if protracted DU exposure produces tumors in vivo, the implication from these in vitro results is that the risk of cancer induction from internalized DU exposure may be comparable to other biologically reactive and carcinogenic heavy-metal compounds (e.g., nickel).

Modulation of radiation response of human tumour cells by the differentiation inducers, phenylacetate and phenylbutyrate

The aromatic fatty acids phenylacetate (PA) and phenylbutyrate (PB) are novel antitumour agents currently under clinical evaluation. Their ability to induce tumour differentiation in laboratory models and their low clinical toxicity profile makes them promising candidates for combination with conventional therapies. In the present studies, we characterized the interactions between these aromatic fatty acids and radiation, using as a model cell lines derived from cancers of the prostate, breast, brain and colon. Analysis of the radiation response of the tumour lines using the linear-quadratic model, demonstrated that cellular exposure to pharmacological, non-toxic concentrations of either PA or PB resulted in time-dependent and contrasting changes in radiation response. While drug pretreatment for 24 h reduced radiation sensitivity (significant alterations in both alpha and beta parameters), pre treatment for 72 h significantly increased radiosensitivity (significant alterations in alpha and beta parameters). In replicating tumour cells, these changes were accompanied by a gradual G1-phase arrest. Cytostasis alone, however, could not explain radiosensitization, as similar alterations in radiation response were documented also in non-cycling cells. Modulation of tumour radiobiology by PA and PB was tightly correlated with early rise followed by decline in intracellular glutathione levels and the activity of antioxidant enzymes such as catalase, superoxide dismutase, glutathione reductase, glutathione peroxidase and glutathione S-transferase. Although in vitro findings identify the aromatic fatty acids PA and PB as a new class of non-toxic modulators of radiation response, the antagonistic effect of these compounds on radiation response needs further examination. Our data strongly suggest that for PA or PB to have a role in clinical radiotherapy, appropriate scheduling of combination therapies must take into account their time-dependent effects in order to achieve clinical radiosensitization.