Electrochemical biosensor for aerobic acetate detection

There is an increasing demand on alternatives methods to animal testing. Numerous health parameters have been already studied using in vitro devices able to mimic the essential functions of the organs, being the real-time monitoring and response to stimuli their main limitations. Regarding the health of the gut, the short chain fatty acids, and particularly acetate, have emerged as key biomarkers to evaluate gut healthiness and disease development, although the number of acetate biosensors is still very low. This article presents a microbial biosensor based on fully biocompatible materials which is able to detect acetate in aerobic conditions in the range between 11 and 50 mM, and without compromising the viability and function of either bacteria (>90% viability) or mammalian cells (>80% viability). The detection mechanism is based on the metabolism of acetate by Escherichia coli bacteria immobilized on the transducer surface. Ferricyanide is used as a redox mediator to transfer electrons from the acetate metabolism in the bacterial cells to the transducer. High bacterial concentrations are immobilized in the transducer surface (109 cfu mL-1) by electrodeposition of conductive alginate hydrogels doped with reduced graphene oxide. The results show successful outcomes to exploit bacteria as a biosensing tool, based on the use of inkjet printed transducers, biocompatible materials and cell entrapment technologies.

Replication of SARS-CoV-2 in adipose tissue determines organ and systemic lipid metabolism in hamsters and humans

Zickler et al. describe SARS-CoV-2 RNA in post-mortem samples of human adipose tissue. In the hamster model, SARS-CoV-2 propagation in adipose tissue leads to specific changes in lipid metabolism, which are reflected in lipidome patterns of hamster and human plasma.

High estradiol and low testosterone levels are associated with critical illness in male but not in female COVID-19 patients: a retrospective cohort study

Male sex was repeatedly identified as a risk factor for death and intensive care admission. However, it is yet unclear whether sex hormones are associated with disease severity in COVID-19 patients. In this study, we analysed sex hormone levels (estradiol and testosterone) of male and female COVID-19 patients (n = 50) admitted to an intensive care unit (ICU) in comparison to control non-COVID-19 patients at the ICU (n = 42), non-COVID-19 patients with the most prevalent comorbidity (coronary heart diseases) present within the COVID-19 cohort (n = 39) and healthy individuals (n = 50). We detected significantly elevated estradiol levels in critically ill male COVID-19 patients compared to all control cohorts. Testosterone levels were significantly reduced in critically ill male COVID-19 patients compared to control cohorts. No statistically significant differences in sex hormone levels were detected in critically ill female COVID-19 patients, albeit similar trends towards elevated estradiol levels were observed. Linear regression analysis revealed that among a broad range of cytokines and chemokines analysed, IFN-γ levels are positively associated with estradiol levels in male and female COVID-19 patients. Furthermore, male COVID-19 patients with elevated estradiol levels were more likely to receive ECMO treatment. Thus, we herein identified that disturbance of sex hormone metabolism might present a hallmark in critically ill male COVID-19 patients.

Patterns of palliative radiotherapy fractionation for brain metastases patients in New South Wales, Australia

BACKGROUND AND PURPOSE

There is a paucity of studies examining variation in the use of palliative radiation therapy (RT) fractionation for brain metastases. The aim of this study is to assess variation in palliative RT fractionation given for brain metastases in New South Wales (NSW), Australia, and identify factors associated with variation.

MATERIALS AND METHODS

This is a population-based cohort of patients who received whole brain RT (WBRT) for brain metastases (2009-2014), as captured in the NSW Central Cancer Registry. A logistic regression model was used to identify factors associated with fractionation type.

RESULTS

Of the 2,698 patients that received WBRT, 1,389 courses (51%) were < 6 fractions, 1,050 courses (39%) were 6-10 fractions, and 259 courses (10%) were > 10 fractions. Older patients were more likely to be treated with shorter courses (P < 0.0001). Patients with primary lung cancers were more likely to receive shorter courses compared with other primary cancers (P < 0.0001). Patients without surgical excision were more likely to receive < 6 fractions compared to those who underwent surgical excision. Shorter courses were more likely to be delivered to patients with the most disadvantaged socioeconomic status (SES) compared with patients with the least disadvantaged SES (P < 0.0001). There were significant fluctuations in the proportion of courses using lower number of fractions over time from 2009 to 2014, but no apparent trend (P = 0.02). There was wide variation in the proportion of shorter courses across residence local health districts, ranging from 24% to 69% for < 6 fractions, 21% to 72% for 6-10 fractions, and 4% to 20% for > 10 fractions (P < 0.0001).

CONCLUSION

This study has identified significant unwarranted variations in fractionation for WBRT in NSW. Accelerating the uptake of shorter fractionation regimens, if warranted through evidence, should be prioritised to enhance evidence-based care.

Enhanced tenacity of mycobacterial aerosols from necrotic neutrophils

The tuberculosis agent Mycobacterium tuberculosis is primarily transmitted through air, but little is known about the tenacity of mycobacterium-containing aerosols derived from either suspensions or infected neutrophils. Analysis of mycobacterial aerosol particles generated from bacterial suspensions revealed an average aerodynamic diameter and mass density that may allow distant airborne transmission. The volume and mass of mycobacterial aerosol particles increased with elevated relative humidity. To more closely mimic aerosol formation that occurs in active TB patients, aerosols from mycobacterium-infected neutrophils were analysed. Mycobacterium-infected intact neutrophils showed a smaller particle size distribution and lower viability than free mycobacteria. In contrast, mycobacterium-infected necrotic neutrophils, predominant in M. tuberculosis infection, revealed particle sizes and viability rates similar to those found for free mycobacteria, but in addition, larger aggregates of viable mycobacteria were observed. Therefore, mycobacteria are shielded from environmental stresses in multibacillary aggregates generated from necrotic neutrophils, which allows improved tenacity but emphasizes short distance transmission between close contacts.

Influenza surveillance in Middle East, North, East and South Africa: Report of the 8th MENA Influenza Stakeholders Network

The Middle‐East and Africa Influenza Surveillance Network (MENA‐ISN), established in 2014, includes 15 countries at present. Country representatives presented their influenza surveillance programmes, vaccine coverage and influenza control actions achieved, and provided a list of country surveillance/control objectives for the upcoming 3 years. This report details the current situation of influenza surveillance and action plans to move forward in MENA‐ISN countries. Data were presented at the 8th MENA‐ISN meeting, organized by the Mérieux Foundation that was held on 10‐11 April 2018 in Cairo, Egypt. The meeting included MENA‐ISN representatives from 12 countries (Algeria, Egypt, Jordan, Kenya, Lebanon, Libya, Morocco, Pakistan, Saudi Arabia, South Africa, Tunisia and United Arab Emirates) and experts from the Canadian Centre for Vaccinology, and the World Health Organization. Meeting participants concluded that influenza remains a significant threat especially in high‐risk groups (children under‐5, elderly, pregnant women and immunosuppressed individuals) in the MENA‐ISN region. Additional funding and planning are required by member countries to contain this threat. Future meetings will need to focus on creative and innovative ways to inform policy and initiatives for vaccination, surveillance and management of influenza‐related morbidity and mortality especially among the most vulnerable groups of the population.

Online oxygen monitoring using integrated inkjet-printed sensors in a liver-on-a-chip system

The demand for real-time monitoring of cell functions and cell conditions has dramatically increased with the emergence of organ-on-a-chip (OOC) systems. However, the incorporation of co-cultures and microfluidic channels in OOC systems increases their biological complexity and therefore makes the analysis and monitoring of analytical parameters inside the device more difficult. In this work, we present an approach to integrate multiple sensors in an extremely thin, porous and delicate membrane inside a liver-on-a-chip device. Specifically, three electrochemical dissolved oxygen (DO) sensors were inkjet-printed along the microfluidic channel allowing local online monitoring of oxygen concentrations. This approach demonstrates the existence of an oxygen gradient up to 17.5% for rat hepatocytes and 32.5% for human hepatocytes along the bottom channel. Such gradients are considered crucial for the appearance of zonation of the liver. Inkjet printing (IJP) was the selected technology as it allows drop on demand material deposition compatible with delicate substrates, as used in this study, which cannot withstand temperatures higher than 130 °C. For the deposition of uniform gold and silver conductive inks on the porous membrane, a primer layer using SU-8 dielectric material was used to seal the porosity of the membrane at defined areas, with the aim of building a uniform sensor device. As a proof-of-concept, experiments with cell cultures of primary human and rat hepatocytes were performed, and oxygen consumption rate was stimulated with carbonyl-cyanide-4-(trifluoromethoxy)phenylhydrazone (FCCP), accelerating the basal respiration of 0.23 ± 0.07 nmol s-1/106 cells up to 5.95 ± 0.67 nmol s-1/106 cells s for rat cells and the basal respiration of 0.17 ± 0.10 nmol s-1/106 cells by up to 10.62 ± 1.15 nmol s-1/106 cells for human cells, with higher oxygen consumption of the cells seeded at the outflow zone. These results demonstrate that the approach of printing sensors inside an OOC has tremendous potential because IJP is a feasible technique for the integration of different sensors for evaluating metabolic activity of cells, and overcomes one of the major challenges still remaining on how to tap the full potential of OOC systems.

Simultaneous monitoring of Staphylococcus aureus growth in a multi-parametric microfluidic platform using microscopy and impedance spectroscopy

We describe the design, construction, and characterization of a scalable microfluidic platform that allows continuous monitoring of biofilm proliferation under shear stress conditions. Compared to other previous end-point assay studies, our platform offers the advantages of integration into multiple environments allowing simultaneous optical microscopy and impedance spectroscopy measurements. In this work we report a multi-parametric sensor that can monitor the growth and activity of a biofilm. This was possible by combining two interdigitated microelectrodes (IDuEs), and punctual electrodes to measure dissolved oxygen, K+, Na+ and pH. The IDuE has been optimized to permit sensitive and reliable impedance monitoring of Staphylococcus aureus V329 growth with two- and four-electrode measurements. We distinguished structural and morphological changes on intact cellular specimens using four-electrode data modeling. We also detected antibiotic mediated effects using impedance. Results were confirmed by scanning electrode microscopy and fluorescence microscopy after live/dead cell staining. The bacitracin mediated effects detected with impedance prove that the approach described can be used for guiding the development of novel anti-biofilm agents to better address bacterial infection.

Non-invasive assessment of corneal endothelial permeability by means of electrical impedance measurements

The permeability of the corneal endothelial layer has an important role in the correct function of the cornea. Since ionic permeability has a fundamental impact on the passive electrical properties of living tissues, here it is hypothesized that impedance methods can be employed for assessing the permeability of the endothelial layer in a minimally invasive fashion. Precisely, the main objective of the present study is to develop and to analyze a minimally invasive method for assessing the electrical properties of the corneal endothelium, as a possible diagnostic tool for the evaluation of patients with endothelial dysfunction. A bidimensional model consisting of the main corneal layers and a four-electrode impedance measurement setup placed on the epithelium has been implemented and analyzed by means of the finite elements method (FEM). In order to obtain a robust indicator of the permeability of the endothelium layer, the effect of the endothelium electrical properties on the measured impedance has been studied together with reasonable variations of the other model layers. Simulation results show that the impedance measurements by means of external electrodes are indeed sufficiently sensitive to the changes in the electrical properties of the endothelial layer. It is concluded that the method presented here can be employed as non-invasive method for assessing endothelial layer function.

Single-walled carbon nanotubes deposited on surface electrodes to improve interface impedance

A suspension of commercially available single-walled carbon nanotubes (SWNTs) is directly deposited onto a platinum multielectrode array surface. This is a novel and easy method to reduce interface impedance values which can be used instead of electromodified electrodes. This paper shows that this deposition method is a useful technique for the modification of patterned electrodes ranging in the micro scale. A thorough comparison between the common and well-known black platinum versus SWNTs, as interface material for different electrode areas, has been carried out. SWNTs-based electrodes smaller than 40 microm Ø improve the interface impedance values when compared to black platinum-modified electrodes of the same size. The best results can be found for the 10 microm Ø, which improves the electrode resistance by 25% in comparison with the black platinum ones. The lower resistance and higher capacitance calculated for the 40 microm diameter SWNTs-based electrode, in comparison with black platinum, also evidence a clear increment of the effective area, which is directly related to the impedance decrease.

Prevalence of Chlamydia trachomatis and associated risk factors in women inmates admitted to a youth offenders institute in the UK

The aim of the study was to estimate the prevalence of Chlamydia trachomatis genital infections in young women inmates aged 17-21 located on the Youth Offenders Institute of HMP Holloway. The study consisted of a questionnaire and a urine sample for analysis. A health advisor administered a questionnaire to establish sociodemographic profile, sexual history and illicit drug use. C. trachomatis was diagnosed using a nucleic acid amplification test. Overall, the prevalence of C. trachomatis was 13.2%. Drug use was common with 41.2% using crack cocaine and 17.3% using intravenous heroin. A majority (80.2%) reported not using condoms during the last sexual encounter and 62.6% had a history of a previous pregnancy. Over half (53.3%) had a previous sexually transmitted infection (STI) screening and 74.7% had never been previously diagnosed with a STI. Sexual health programmes in prisons should include screening as well as education about STI risk reduction and drug prevention.

Differential polymerase activity in avian and mammalian cells determines host range of influenza virus

As recently shown, mutations in the polymerase genes causing increased polymerase activity in mammalian cells are responsible for the adaptation of the highly pathogenic avian influenza virus SC35 (H7N7) to mice (G. Gabriel et al., Proc. Natl. Acad. Sci. USA 102:18590-18595, 2005). We have now compared mRNA, cRNA, and viral RNA levels of SC35 and its mouse-adapted variant SC35M in avian and mammalian cells. The increase in levels of transcription and replication of SC35M in mammalian cells was linked to a decrease in avian cells. Thus, the efficiency of the viral polymerase is a determinant of both host specificity and pathogenicity.

Évaluation à court et à moyen terme d'une démarche qualité pour la prise en charge de la douleur postopératoire dans un CHU

OBJECTIVES

Evaluation of the short- and medium-term impact of a postoperative pain management quality assurance programme in a university hospital.

STUDY DESIGN

Prospective study.

MATERIALS AND METHODS

In 1998: chart review and survey of patients and professionals. Principal corrective actions: support for evaluation and tracking of potentially painful surgical procedures, prescription form including an emergency treatment plan, distribution of a set of guidelines. Evaluation was identical during the quality assurance programme and three years later, in 2003.

RESULTS

In 2003, information regarding postoperative analgesia was received by 70% of patients and understood by 99% (50% in 1998, p<0.001). Sixty-two percent of patients were totally satisfied with their doctors in 2003 vs 75% in 1998 (NS). Pain was documented in 63.1% of charts in 2003, vs 10% in 1998 (p<0.001). Hundred percent of doctors were aware of the analgesic protocols in 2003 vs 69% in 1998 (p<0.02). In 2003, the treatment of analgesic side effects was known by 86% of doctors vs 29% in 1998 and these effects were looked for by 57% of caregivers in 2003 vs 11% in 1998 (p<0.001).

CONCLUSION

Management of postoperative pain has progress significantly and the quality indicators used for evaluation have improved. Patients are better informed, which raises standards. The programme will be extended to all other surgical departments of the hospital, under the authority of CLUDS (Committee for Pain Control and Palliative Care).

Predictive factors for the underutilization of adjuvant chemotherapy in colon cancer in Southwestern Sydney

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Background: Adjuvant chemotherapy improves survival in stage III and high risk stage II colon cancers and is therefore recommended in current treatment guidelines. Despite this, retrospective studies demonstrate that utilization rates remain suboptimal in Australia and other countries. In this study we aimed to identify predictive factors for adjuvant chemotherapy underutilization in the Southwestern Sydney Area Health Service (SWSAHS). Methods: We examined data collected on all patients with a diagnosis of stage II or III colon and rectosigmoid cancers from SWSAHS colorectal database between 1997 and 2003. Follow-up and survival were calculated until October 2005. SPSS was used for statistical analysis and Kaplan-Meier for survival analysis. Results: 704 patients were identified. The overall adjuvant chemotherapy utilization rate was 48% (68% for stage III and 26% for stage II). Overall 5 year survival was 69% for patients who received adjuvant chemotherapy compared with 39% for those who did not receive chemotherapy (p<0.001). The main predictive factor identified for not receiving chemotherapy in both stages was increasing age. Rates of utilization of adjuvant chemotherapy for stage III colon cancer were 90% (<50 yrs), 81% (50–69 yrs) and 50% (70+ yrs). The trend was similar for stage II patients with corresponding utilization rates of 69%, 37% and 10%, respectively. The difference in chemotherapy utilization by age groups is highly significant (p<0.001). Other factors including sex, health insurance status, site of primary colon cancer and index of relative socioeconomic disadvantage did not show significant difference in chemotherapy usage. We were unable to evaluate the effect of co-morbidity on chemotherapy use from our database. Conclusions: Increasing age is the single most important predictive factor in the underutilization of adjuvant chemotherapy in colon cancer despite evidence that the elderly can accrue the same benefit from adjuvant chemotherapy as their younger counterparts.

No significant financial relationships to disclose.

The viral polymerase mediates adaptation of an avian influenza virus to a mammalian host

Mammalian influenza viruses are descendants of avian strains that crossed the species barrier and underwent further adaptation. Since 1997 in southeast Asia, H5N1 highly pathogenic avian influenza viruses have been causing severe, even fatal disease in humans. Although no lineages of this subtype have been established until now, such repeated events may initiate a new pandemic. As a model of species transmission, we used the highly pathogenic avian influenza virus SC35 (H7N7), which is low-pathogenic for mice, and its lethal mouse-adapted descendant SC35M. Specific mutations in SC35M polymerase considerably increase its activity in mammalian cells, correlating with high virulence in mice. Some of these mutations are prevalent in chicken and mammalian isolates, especially in the highly pathogenic H5N1 viruses from southeast Asia. These activity-enhancing mutations of the viral polymerase complex demonstrate convergent evolution in nature and, therefore, may be a prerequisite for adaptation to a new host paving the way for new pandemic viruses.

Non-herbal nutritional supplements-the next wave: a comprehensive review of risks and benefits for the C-L psychiatrist

The continuing popularity of complementary medicine has led to the frequent appearance of new products in the marketplace. Non-herbal supplements are now a popular choice for patients seeking relief from a variety of medical conditions. As with herbal medicines, there are concerns about the safety of these products in those with physical illness. Clearly, consultation-liaison psychiatrists will encounter patients using non-herbal products or inquiring about them. This article seeks to provide knowledge about the risks and benefits of non-herbal supplements that consultation-liaison psychiatrists are likely to encounter.

Dystrophinopathy presenting as congenital muscular dystrophy

We report a 3 1/2-year-old boy with congenital hypotonia, calf pseudohypertrophy, markedly delayed motor milestones and joint contractures. He was initially diagnosed to have congenital muscular dystrophy on the basis of the age of onset, a myopathic EMG, an elevated creatine kinase and a dystrophic muscle biopsy. Subsequently, dystrophin immunocytochemistry and immunoblot analysis showed complete absence of dystrophin. We suggest that male cases of CMD should undergo dystrophin analysis, if there is calf hypertrophy and markedly elevated CK (> 2000 U/l).

New hereditary malformation syndrome of unusual facial appearance, skeletal deformities, and musculoskeletal and sensory defects

We report on a new syndrome characterized by specific and striking facial abnormalities, arthrogrypotic skeletal deformities, and neuromuscular and sensory defects in a large Greek Cypriot family. The hereditary transmission appears to be autosomal dominant with quite variable expressivity.

Murine mast cells synthesize basement membrane components. A potential role in early fibrosis

Mast cells are resident in tissues, particularly in association with endothelial and epithelial cell basement membranes, and increase at sites of inflammation, injury, and fibrosis. Although mast cells are known to both release and generate proinflammatory molecules in response to inflammatory stimuli, little is known about their normal biologic function. Here we demonstrate that IL-3-dependent mouse PT18 mast cells, mouse bone marrow-derived mast cells, and rat basophilic leukemia cells express large amounts of mRNA for collagen IV, laminin, and heparan sulfate proteoglycan. Western blot analysis confirmed that mast cells synthesize and secrete significant amounts collagen IV and laminin B1 and B2 chains. These data suggest that mast cells may contribute to normal tissue repair and/or the early overproduction of basement membrane components seen in a variety of fibrotic conditions.

Response of serum p24 antigen and antibody to p24 antigen in patients with AIDS and AIDS-related complex treated with zidovudine

In an open study of the treatment of patients with AIDS-related complex (ARC) and AIDS with zidovudine, we evaluated the response of serum p24 antigen (p24Ag) and antibody to p24Ag (anti-p24) levels. Before treatment, serum from 49 out of 73 (67%) patients was p24Ag-positive, and of these patients 42 received zidovudine 800-1200 mg daily for greater than 4 weeks and had a baseline mean serum level of p24Ag of 119 pg/ml (s.e. 15.7). On zidovudine there was a reduction of p24Ag to 21.12% (s.e. 4.76) of pretreatment values at 3 months; however, there was a subsequent trend for levels after 6 months to increase to greater than 50% of pretreatment levels at 12 months. Serum levels of anti-p24 were measured in 26 patients. Of 16 patients whose serum contained p24Ag and 10 whose serum did not, four and nine, respectively, had detectable levels of anti-p24. There was no significant change in the serum anti-p24 with zidovudine therapy.

Morphometric and freeze-fracture studies on peripheral nerve in shiverer mice

Observations have been made on the peripheral nerves of shiverer (shi/shi) mice in comparison with control animals. Although this mutant lacks P1 myelin basic protein in peripheral and central myelin, myelin is defective only in the central nervous system. No ultrastructural abnormalities were observed in the shiverer nerves. Myelin spacing was normal. The density and distribution of intramembranous particles on the E and P faces of myelin and in the axolemma of myelinated and unmyelinated axons did not differ between the shiverer and control mice. Morphometric studies showed that external myelinated fiber diameter was significantly less and that myelin thickness was slightly but significantly greater in relation to axon diameter in the shiverer mice, suggesting a minor degree of axonal atrophy. It is concluded that P1 protein is not necessary for the formation and maintenance of the normal structure of peripheral myelin. The failure to detect differences in intramembranous particle density in myelin between shiverer and control mice indicates that P1 protein is not detected in freeze-fracture preparations.

Freeze-fracture observations on human peripheral nerve

A study has been made on the appearances in normal human sural nerve using freeze-fracture replication techniques. These have included qualitative observations on the major membrane systems and quantitative assessments of the density of intramembranous particles in the perineurial cell membranes, myelin, the nodal and internodal axolemma of myelinated nerve fibres and the axolemma of unmyelinated axons. The results have been compared with those obtained in other species.

Peripheral nerve intramembranous particle density and distribution in chronic streptozotocin-induced diabetes in rats

Freeze-fracture studies have been made on the sciatic nerve of rats with chronic streptozotocin-induced diabetes mellitus. The density of intramembranous particles was reduced in both P and E faces of the axolemma of myelinated and unmyelinated axons, in myelin and in the perineurial cells. This may reflect a general reduction in protein synthesis, or excessive protein degradation, related to the diabetic state. The perineurial cells also showed gap junctions which are not normally present in adult rat peripheral nerve. These may represent a reaction to changes in perineurial activity consequent to alterations in the endoneurial tissue fluid.