1362 ANTICHOLINERGIC PRESCRIBING HABITS AND ITS ASSOCIATIONS IN A COMMUNITY POPULATION OF PEOPLE LIVING WITH DEMENTIA

Introduction

Many commonly prescribed medications have inadvertent anticholinergic effects. People with Dementia (PwD) are more vulnerable to these effects and at risk of adverse outcomes, the risk being higher with a greater degree of anticholinergic exposure. We investigated prescribing patterns and Anticholinergic burden (ACB) in a cohort of community-dwelling older adults with dementia and aimed to explore the effect of ACB on cognition, mood, and quality of life(QoL).

Method

The medication and demographic information for 87 (39 female) community-dwelling PwD were obtained from Electronic Care Summaries. We used the German Anticholinergic Burden Scale (GABS) to measure ACB. Additionally, we investigated associations between ACB and cognitive (ADAS-Cog), functional (BADL) and QoL (DemQoL) assessments.

Results

28.7% of participants had a clinically significant score (ACB> 2). The most commonly prescribed medications with ACB were Lansoprazole(18.3%), Mirtazapine(12.6%) and Codeine(12.6%). ACB was higher in males and negatively correlated with age, r(87)=-.21,p=.03. There was no association between ACB and cognition, QoL, functional independence, and neuropsychiatric symptoms. Over six months, PLWD with no ACB had a greater negative change in neuropsychiatric symptoms[t(18)=2.27,p=.04] and functional independence[t(23)=-3.8,p=.001], indicating greater dependence and worsening neuropsychiatric symptoms.

Conclusion

A third of PLWD in the community had clinically significant ACB. No ACB was associated with worsening neuropsychiatric symptoms and functional dependence over a six-month period. Community prescribers should consider regular medication reviews with PLWD and carers to ensure medications are prescribed safely and appropriately.

1415 NOVEL APPROACHES TO POST DISCHARGE CARE. REMOTE HEALTHCARE MONITORING SYSTEMS FOLLOWING TRAUMATIC BRAIN INJURY IN OLDER ADULTS

Introduction

Major trauma including Traumatic Brain Injury (TBI) is an increasingly common cause of hospitalisation in older adults (OAs). We studied post-discharge recovery from TBI using a remote healthcare monitoring system that captures data on activity and sleep. We aim to assess the feasibility and acceptability of this technology to monitor recovery at home following a significant acute health event in OAs.

Methods

We installed Minder, a remote healthcare monitoring system, in recently discharged patients >60 years with moderate-severe TBI. We present descriptive analyses of post-discharge recovery for two males, corroborating data from Minder against verified activities and events. We recorded semi-structured interviews assessing acceptability. Both participants have similar household set-up, multimorbidity profiles and clinical frailty scores; however, one participant has prior cognitive impairment (PAT1), and one does not (PAT2).

Results

We present 10 weeks of sleep and activity data from Minder and feedback from interviews. Data observed from PAT1 revealed habitual patterns of activity and sleep. These remained stable, despite discrete clinical events. Conversely, PAT2's data revealed irregular sleep patterns that became increasingly fragmented. Activity was detected in multiple rooms throughout the house at night, consistent with carer reports of night-time wandering. Increased overnight activity coincided with multiple falls, prompting increased care provision. Initial feedback from interviews was the technology helped participants and those involved in their care feel supported.

Conclusions

As pressure on services mounts, novel approaches to post-discharge care are of increasing importance. Remote healthcare monitoring can provide high temporal resolution data offering ‘real world’ insights into the effects of significant health events in OAs. Our provisional results support our hypothesis that use of this technology is feasible and acceptable for frail, multimorbid participants and highlights the substantial potential of this technology to help clinicians improve community-based care and more effectively monitor interventions and chronic conditions.

P36 Consent for Orthopaedic Trauma Surgery during the COVID-19 Pandemic

Surgical services have been hugely disrupted by COVID-19 and have had to evolve rapidly in response. The best practice for consent mandates that risks associated with surgical treatment during a pandemic be discussed. This study aimed to assess whether patients undergoing orthopaedic operations were being consented for the risk of contacting COVID-19 and ITU care.

All orthopaedic consent forms from four-week periods in March, June and July were reviewed. Measures such as staff education were implemented after the second cycle.

Of consent forms for 37 operations performed in March, only 1 mentioned the risk of contracting COVID-19 and zero mentioned ITU. During June, 89 consent forms were reviewed, 32 mentioned COVID-19 and 10 discussed ITU admission. Following educational measures, the third cycle showed a significant improvement as of 100 consent form records available for review, 73 included risk of COVID-19 whilst 26 mentioned ITU.

The results show that earlier in the pandemic, surgeons at our centre were not counselling patients regarding COVID-19. This improved slightly between the first and second cycles, likely reflecting increased awareness of the nosocomial transmission of COVID-19. Educational measures contributed to a significant improvement in the third cycle. Planned interventions include use of electronic consent forms which incorporate COVID-19 infection and associated risks.

161 Does the Weather Contribute to Admissions of Neck of Femur Fractures?

Introduction

The effects of weather on overall mortality are well documented. Anecdotally, icy conditions are perceived to result in more falls and admissions for neck of femur (NOF) fractures. The aim of this unfunded pilot study was to determine whether relationships could be extracted or at least not ruled out by analysing a small dataset, and so give impetus to a larger project.

Methods

Seven trauma units across north west London were identified and NOF fracture data extracted for five years. Visual inspection of the time series, consideration of the weather on specific days and correlation analysis were used to assess causal links between fracture numbers and a variety of weather parameters (temperature, rainfall, wind and ice risk).

Results

Overall, 10,929 individuals with hip fractures were admitted over the five-year period. The highest number of admissions in a day was 14. No clear association was found between a weather parameter and daily admissions. However, when accumulated to a weekly timescale, a negative relationship with maximum temperature was found. No seasonal cycle was detected.

Conclusion

The lack of a daily relationship and presence of a weekly relationship points to a possible delayed response to weather or insufficient daily data to extract a signal. The inconclusive results also indicate that more socioeconomic data will need to be used in future studies, requiring a larger data sample. In addition, even in cold weather an urban environment may not create icy conditions, being ameliorated by the heat island effect and gritting.

Diagnostic Salivary Tests for SARS-CoV-2

The diagnosis of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection relies on the detection of viral RNA by real-time reverse transcription polymerase chain reaction (rRT-PCR) performed with respiratory specimens, especially nasopharyngeal swabs. However, this procedure requires specialized medical personnel, centralized laboratory facilities, and time to provide results (from several hours up to 1 d). In addition, there is a non-negligible risk of viral transmission for the operator who performs the procedure. For these reasons, several studies have suggested the use of other body fluids, including saliva, for the detection of SARS-CoV-2. The use of saliva as a diagnostic specimen has numerous advantages: it is easily self-collected by the patient with almost no discomfort, it does not require specialized health care personnel for its management, and it reduces the risks for the operator. In the past few months, several scientific papers, media, and companies have announced the development of new salivary tests to detect SARS-CoV-2 infection. Posterior oropharyngeal saliva should be distinguished from oral saliva, since the former is a part of respiratory secretions, while the latter is produced by the salivary glands, which are outside the respiratory tract. Saliva can be analyzed through standard (rRT-PCR) or rapid molecular biology tests (direct rRT-PCR without extraction), although, in a hospital setting, these procedures may be performed only in addition to nasopharyngeal swabs to minimize the incidence of false-negative results. Conversely, the promising role of saliva in the diagnosis of SARS-CoV-2 infection is highlighted by the emergence of point-of-care technologies and, most important, point-of-need devices. Indeed, these devices can be directly used in workplaces, airports, schools, cinemas, and shopping centers. An example is the recently described Rapid Salivary Test, an antigen test based on the lateral flow assay, which detects the presence of the virus by identifying the spike protein in the saliva within a few minutes.

Suspected non-Alzheimer's pathology - Is it non-Alzheimer's or non-amyloid?

Neurodegeneration, the progressive loss of neurons, is a major process involved in dementia and age-related cognitive impairment. It can be detected clinically using currently available biomarker tests. Suspected Non-Alzheimer Pathology (SNAP) is a biomarker-based concept that encompasses a group of individuals with neurodegeneration, but no evidence of amyloid deposition (thereby distinguishing it from Alzheimer's disease (AD)). These individuals may often have a clinical diagnosis of AD, but their clinical features, genetic susceptibility and progression can differ significantly, carrying crucial implications for precise diagnostics, clinical management, and efficacy of clinical drug trials. SNAP has caused wide interest in the dementia research community, because it is still unclear whether it represents distinct pathology separate from AD, or whether in some individuals, it could represent the earliest stage of AD. This debate has raised pertinent questions about the pathways to AD, the need for biomarkers, and the sensitivity of current biomarker tests. In this review, we discuss the biomarker and imaging trials that first recognized SNAP. We describe the pathological correlates of SNAP and comment on the different causes of neurodegeneration. Finally, we discuss the debate around the concept of SNAP, and further unanswered questions that are emerging.

Tau imaging in neurodegenerative diseases

Aggregated tau protein is a major neuropathological substrate central to the pathophysiology of neurodegenerative diseases such as Alzheimer's disease (AD), frontotemporal dementia, progressive supranuclear palsy, corticobasal degeneration and chronic traumatic encephalopathy. In AD, it has been shown that the density of hyperphosphorylated tau tangles correlates closely with neuronal dysfunction and cell death, unlike β-amyloid. Until now, diagnostic and pathologic information about tau deposition has only been available from invasive techniques such as brain biopsy or autopsy. The recent development of selective in-vivo tau PET imaging ligands including [(18)F]THK523, [(18)F]THK5117, [(18)F]THK5105 and [(18)F]THK5351, [(18)F]AV1451(T807) and [(11)C]PBB3 has provided information about the role of tau in the early phases of neurodegenerative diseases, and provided support for diagnosis, prognosis, and imaging biomarkers to track disease progression. Moreover, the spatial and longitudinal relationship of tau distribution compared with β - amyloid and other pathologies in these diseases can be mapped. In this review, we discuss the role of aggregated tau in tauopathies, the challenges posed in developing selective tau ligands as biomarkers, the state of development in tau tracers, and the new clinical information that has been uncovered, as well as the opportunities for improving diagnosis and designing clinical trials in the future.

Bevacizumab, a vascular endothelial growth factor (VEGF) specific antibody reduces interstitial fluid pressure (IFP) in human rectal cancer xenograft (HT29) by day 5: Is this evidence for rescheduling its timing relative to chemotherapy?

4043

Background: Interstitial fluid pressure (IFP) of most solid tumours is increased relative to normal tissues; this is thought to be associated with the development of structurally and functionally abnormal blood and lymphatic vessels and interstitial fibrosis. Such interstitial hypertension creates a barrier for tumour transvascular transport, consequently compromising the delivery and efficacy of chemotherapy. We investigated the effect of Bevacizumab on IFP of a human rectal cancer xenograft. Methods: SCID mice bearing subcutaneous HT29 tumours of =8.5 mm diameter received a single dose of 10 mg/kg Bevacizumab intraperitoneally; controls received saline. Tumour IFP was measured in sedated mice (Hypnorm) on days 1, 3 and 5 post injection, using the wick-in-needle technique. Experiments were conducted under Home Office licence and approved by the local ethical committee. Results: Groups of 8 treated and control tumours were examined on days 1, 3 and 5 (n = 48). IFP was significantly lower (p<0.0001) on day 5 in treated than control tumours (mean ± SD 15.1 ± 4.7 cf 36.9 ± 5.6 mm Hg). No significant differences (p>0.05) between treated and control groups were seen on day 1 (31.8 ± 3.5 cf 30.6 ± 3.1 mm Hg) or day 3 (33.4 ± 5.5 cf 31.5 ± 3.2 mm Hg). No data were acquired on day 7 as the tumours ulcerated. Conclusions: Our data show that Bevacizumab causes a significant reduction of tumour IFP, but not until 5 days after treatment. Reduced IFP could augment uptake of cytotoxic drugs into tumour cells, hence timing of Bevacizumab relative to the first dose of chemotherapy could be of critical importance.

No significant financial relationships to disclose.

Novel antitenascin antibody with increased tumour localisation for Pretargeted Antibody-Guided RadioImmunoTherapy (PAGRIT)

The Pretargeted Antibody-Guided RadioImmunoTherapy (PAGRIT) method is based on intravenous, sequential administration of a biotinylated antibody, avidin/streptavidin and (90)Y-labelled biotin. The hybridoma clone producing the monoclonal antitenascin antibody BC4, previously used for clinical applications, was found not suitable for further development because of the production of an additional, nonfunctional light chain. In order to solve this problem, the new cST2146 hybridoma clone was generated. The monoclonal antibody ST2146, produced by this hybridoma, having the same specificity as BC4 but lacking the nonfunctional light chain, was characterised. ST2146 was found able to bind human tenascin at an epitope strictly related, if not identical, to the antigenic epitope of BC4. It showed, compared to BC4, higher affinity and immunoreactivity and similar selectivity by immunohistochemistry. Biodistribution studies of biotinylated ST2146 and three other monoclonal antitenascin antibodies showed for ST2146 the highest and more specific tumour localisation in HT29-grafted nude mice. On the overall, ST2146 appears to be a good alternative to BC4 for further clinical development of PAGRIT.

Designing multidrug-resistance modulators circumventing the reverse pH gradient in tumours

Multidrug-resistant tumours often exhibit a reverse pH gradient (acid outside), as they have an acid extracellular pH (pHe) and a neutral alkaline intracellular pH (pHi). This study was designed to test the hypothesis that the ability of lipophilic drugs to mediate multidrug resistance (MDR) reversal by interacting with the membrane phospholipids may be correlated with pH in resistant tumours. The permeation properties of five MDR modulators were therefore studied at 37 degrees C by quantifying their ability to induce the leakage of Sulfan blue through unilamellar anionic liposomes, over the range pH 6.5-7.7, and in the absence of any membrane potential (pHe = pHi). The dye leakage induced by two calcium blockers (diltiazem and verapamil) and two antiparasitic agents (thioacridine derivative and mepacrine) was found to significantly increase with the pH of the medium (P < 0.001), whereas that induced by a non-ionic detergent (Triton X-100) showed almost no pH-dependent variations. This process was a cooperative one (0.8 < Hill coefficient < 8.5) and the permeation doses inducing 50% dye leakage (PD50) ranged from 1.6 to 36.0 mM. The permeation ability of the MDR modulators (log(1/PD50)) significantly increased with their octanol-buffer distributions (logD) (slope = 0.35+/-0.06; y intercept = 1.65 +/- 0.14; P < 0.0001) and significantly decreased with their net electric charge (z) (slope = -0.48+/-0.07; y intercept = 2.85+/-0.08; P < 0.0001). A highly significant multiple correlation was found to exist between the variations of log(1/PD50) with those of logD and z (dlog(1/PD50)/dlogD = 0.21 +/- 0.05; dlog(1/PD50)/dz = -0.34+/-0.07; y intercept = 2.27+/-0.17; P < 0.000001). The results provide evidence that in resistant tumours (acid pHe and neutral alkaline pHi), the MDR reversal might be enhanced by favourable drug-membrane interactions if the modulators are designed in the form of highly lipophilic (logP approximately equals 4) mono-basic drugs with a near neutral pKa (pKa approximately equals 7-8).

Thermal dependence of multidrug-resistant-modulator efficiency: a study in anionic liposomes

This study was designed to test the hypothesis that there exists a correlation between the ability of lipophilic drugs to mediate the reversal of multidrug-resistance (MDR) by interacting with the membrane phospholipids and the metabolic level in tissues. The permeation properties of five MDR-modulators were studied by quantifying their ability to induce the leakage of Sulphan blue through unilamellar liposomes, over the temperature range 27-42 degrees C. The dye leakage induced by a non-ionic detergent (Triton X-100), two calcium blockers (diltiazem and verapamil) and two antiparasitic agents (thioacridine derivative and mepacrine) was temperature-dependent. The permeation process was a co-operative one (1.1 < Hill coefficient < 7.5) and the permeation doses inducing 50% dye leakage (PD50) were 1.5 - 14.9 mM. The permeation ability of the MDR-modulators (log(1/PD50)) decreased significantly as the net electric charge (z) increased. The passive dye leakage (deltaG < 0) was found to be an endothermic process (deltaH > 0), favoured by an increase in the membrane disorder (deltaS > 0). The apparent enthalpy factor (deltaH50) associated with 50% dye leakage increased with the net electric charge of the compound, and this energetically non-favoured event was entirely offset by the concomitant increase in the entropy factor (deltaS50). The apparent permeation enthalpy (deltaH50) and entropy (deltaS50) showed the lowest values for Triton X-100 (deltaH50 = 7.1 +/- 0.53 kJ mol(-1), deltaS50 = 76.9 +/- 1.86 Jmol(-1) K(-1)), and the highest values for mepacrine (deltaH50 = 79.5 +/- 3.80 kJmol(-1), deltaS50 = 306.7 +/- 5-97 J mol(-1) K(-1)). When the temperature was increased from 27 to 42 degrees C, the apparent Gibbs free energy (deltaG50) of the dye leakage induced by Triton X-100 decreased by less than 10% of the initial value, and that induced by mepacrine decreased by nearly 40%. The results provide evidence that in tissues with high metabolic levels and therefore high temperatures, MDR-reversal is likely to be enhanced via favourable drug-membrane interactions controlled by the electric charge of the modulators.

Carnitine-dependent changes of metabolic fuel consumption during long-term treatment with valproic acid

Energy metabolism was measured in children receiving long-term treatment with valproic acid. In 8 of 10 randomly selected subjects, the resting respiratory quotient was higher than in age- and sex-matched control subjects (0.91 +/- 0.01 vs 0.87 +/- 0.01; p < 0.05). A shift was observed in fuel consumption, and a significant reduction was found in the amount of fats oxidized (0.68 +/- 0.23 vs 1.18 +/- 0.18 gm.kg-1.day-1), which was accompanied by increased utilization of carbohydrates (5.31 +/- 0.79 vs 3.81 +/- 0.39 gm.kg-1.day-1) in comparison with the control subjects. The resting total energy expenditure was not affected by the treatment. The children with an altered energy consumption pattern (n = 8) received carnitine supplementation for a month; the respiratory quotient then decreased (0.87 +/- 0.02), the oxidation of fats increased (1.42 +/- 0.25), and the consumption of carbohydrates decreased (3.87 +/- 0.79), but no changes in resting energy expenditure were observed. We conclude that carnitine depletion, a known adverse effect of valproic acid administration, may result in inhibited fatty acid oxidation, leading to a shift of substrates utilized from fats to carbohydrates.

Mapping quantitative trait loci (QTLs) for resistance to Gibberella zeae infection in maize

The basic prerequisite for an efficient breeding program to improve levels of resistance to pathogens in plants is the identification of genes controlling the resistance character. If the response to pathogens is under the control of a multilocus system, the utilization of molecular markers becomes essential. Stalk and ear rot caused by Gibberella zeae is a widespread disease of corn: resistance to G. zeae is quantitatively inherited. Our experimental approach to understanding the genetic basis of resistance to Gibberella is to estimate the genetic linkage between available molecular markers and the character, measured as the amount of diseased tissue 40 days after inoculation of a suspension of Fusarium graminearum, the conidial form of G. zeae, into the first stalk internode. Sensitive and resistant parental inbreds were crossed to obtain F1 and F2 populations: the analysis of the segregation of 95 RFLP (restriction fragment length polymorphism) clones and 10 RAPD (random amplified polymorphic DNA) markers was performed on a population of 150 F2 individuals. Analysis of resistance was performed on the F3 families obtained by selfing the F2 plants. Quantitative trait loci (QTL) detection was based either on analysis of regression coefficients between family mean value and allele values in the F2 population, or by means of interval mapping, using MAPMAKER-QTL. A linkage map of maize was obtained, in which four to five genomic regions are shown to carry factors involved in the resistance to G. zeae.

Nucleotide sequence of cDNA coding for saporin-6, a type-1 ribosome-inactivating protein from Saponaria officinalis

We have isolated and sequenced partial cDNA clones that encode SO-6, a ribosome-inactivating protein from Saponaria officinalis. A cDNA library was constructed from the leaves of this plant and screened with synthetic oligonucleotide probes representing various portions of the protein. The deduced amino acid sequence shows the signal peptide and a coding region virtually accounting for the entire amino acid sequence of SO-6. The sequence reveals regions of similarity to other ribosome-inactivating proteins, especially in a region of the molecule where critical amino acid residues might participate in the active site.

A highly conserved repetitive DNA sequence, (TTAGGG)n, present at the telomeres of human chromosomes

A highly conserved repetitive DNA sequence, (TTAGGG)n, has been isolated from a human recombinant repetitive DNA library. Quantitative hybridization to chromosomes sorted by flow cytometry indicates that comparable amounts of this sequence are present on each human chromosome. Both fluorescent in situ hybridization and BAL-31 nuclease digestion experiments reveal major clusters of this sequence at the telomeres of all human chromosomes. The evolutionary conservation of this DNA sequence, its terminal chromosomal location in a variety of higher eukaryotes (regardless of chromosome number or chromosome length), and its similarity to functional telomeres isolated from lower eukaryotes suggest that this sequence is a functional human telomere.

Plasmid pFCE4: a new system of Escherichia coli expression-modification vectors

Two versatile expression-modification vectors were obtained by inserting the origin of replication (ori) of phage f1 into the expression vector pOTS. The resulting plasmids produce large amounts of coding or noncoding ssDNA (depending on ori orientation in pFCE4+ and pFCE4-) and excrete it into the medium as virus-like particles following infection with phage f1. These features make them suitable for dideoxy chain termination sequencing, oligonucleotide directed mutagenesis and gene expression without further manipulations. The human IFN alpha-2 gene, lacking the codon for the first amino acid, cysteine, was efficiently expressed by these vectors.

Calorimetric study of the binding reaction of concanavalin A with immunoglublins

The thermal effects associated with the binding reaction of concanavalin A and immunoglobulins have been measured by calorimetry. IgG solutions do not generate heat on mixing with concanavalin A, confirming the low reactivity of IgG for the lectin molecule. IgM solutions, on the other hand, show a substantial enthalpic contribution of delta H = -24 +/- 1kJ/site for the binding reaction between the polysaccharide chains of human IgM macroglobulin and concanavalin. A stoichiometry is 10 monovalent concanavalin A molecules per intact macroglobulin and two bivalent concanavalin A molecules per two sites on the heavy chain of the reduced macroglobulin subunit.

Calorimetric study of concanavalin A binding to saccharides

The binding of concanavalin A in the dimer form to various saccharides has been studied by calorimetry, and estimates of the binding enthalpy and binding constants have been calculated. Methyl alpha-D-mannoside and methyl alpha-D-glucoside have a -- delta H0 of 21.5 and 11.5 kJ/mol, respectively, at both pH 4 and 4.5. The p-nitrophenyl derivatives react with enthalpic values of 15.6 and 14.6 kJ/mol. The galactosepyranosides show no heat effects during mixing with the protein solutions. The apparent binding enthalpies calculated from the variations of the equilibrium constants with temperature are in good agreement with the values measured experimentally. The two binding sites of the dimer form of concanavalin A are equal and independent, and the low enthalpies obtained do not justify a large conformational change during the reaction. The binding reaction has also been estimated for other sugars normally contained in glycoproteins.