Optimising the balance of acute and intermediate care capacity for the complex discharge pathway: Computer modelling study during COVID-19 recovery in England

Objectives

While there has been significant research on the pressures facing acute hospitals during the COVID-19 pandemic, there has been less interest in downstream community services which have also been challenged in meeting demand. This study aimed to estimate the theoretical cost-optimal capacity requirement for ‘step down’ intermediate care services within a major healthcare system in England, at a time when considerable uncertainty remained regarding vaccination uptake and the easing of societal restrictions.

Methods

Demand for intermediate care was projected using an epidemiological model (for COVID-19 demand) and regressing upon public mobility (for non-COVID-19 demand). These were inputted to a computer simulation model of patient flow from acute discharge readiness to bedded and home-based Discharge to Assess (D2A) intermediate care services. Cost-optimal capacity was defined as that which yielded the lowest total cost of intermediate care provision and corresponding acute discharge delays.

Results

Increased intermediate care capacity is likely to bring about lower system-level costs, with the additional D2A investment more than offset by substantial reductions in costly acute discharge delays (leading also to improved patient outcome and experience). Results suggest that completely eliminating acute ‘bed blocking’ is unlikely economical (requiring large amounts of downstream capacity), and that health systems should instead target an appropriate tolerance based upon the specific characteristics of the pathway.

Conclusions

Computer modelling can be a valuable asset for determining optimal capacity allocation along the complex care pathway. With results supporting a Business Case for increased downstream capacity, this study demonstrates how modelling can be applied in practice and provides a blueprint for use alongside the freely-available model code.

Modelling the Effect of COVID-19 Mass Vaccination on Acute Hospital Admissions

BACKGROUND

Managing high levels of acute COVID-19 bed occupancy can affect the quality of care provided to both affected patients and those requiring other hospital services. Mass vaccination has offered a route to reduce societal restrictions while protecting hospitals from being overwhelmed. Yet, early in the mass vaccination effort, the possible impact on future bed pressures remained subject to considerable uncertainty. The aim of this study was to model the effect of vaccination on projections of acute and intensive care bed demand within a one million resident healthcare system located in South West England.

METHODS

An age-structured epidemiological model of the Susceptible-Exposed-Infectious-Recovered (SEIR) type was fitted to local data up to the time of the study, in early March 2021. Model parameters and vaccination scenarios were calibrated through a system-wide multi-disciplinary working group, comprising public health intelligence specialists, healthcare planners, epidemiologists, and academics. Scenarios assumed incremental relaxations to societal restrictions according to the envisaged UK Government timeline, with all restrictions to be removed by 21 June 2021.

RESULTS

Achieving 95% vaccine uptake in adults by 31 July 2021 would not avert a third wave in autumn 2021 but would produce a median peak bed requirement approximately 6% (IQR: 1% to 24%) of that experienced during the second wave (January 2021). A two-month delay in vaccine rollout would lead to significantly higher peak bed occupancy, at 66% (11% to 146%) of that of the second wave. If only 75% uptake was achieved (the amount typically associated with vaccination campaigns) then the second wave peak for acute and intensive care beds would be exceeded by 4% and 19% respectively, an amount which would seriously pressure hospital capacity.

CONCLUSION

Modelling influenced decision making among senior managers in setting COVID-19 bed capacity levels, as well as highlighting the importance of public health in promoting high vaccine uptake among the population. Forecast accuracy has since been supported by actual data collected following the analysis, with observed peak bed occupancy falling comfortably within the inter-quartile range of modelled projections.

Mem-fractive properties of mushrooms

Memristors close the loop forI-Vcharacteristics of the traditional, passive, semi-conductor devices. A memristor is a physical realisation of the material implication and thus is a universal logical element. Memristors are getting particular interest in the field of bioelectronics. Electrical properties of living substrates are not binary and there is nearly a continuous transitions from being non-memristive to mem-fractive (exhibiting a combination of passive memory) to ideally memristive. In laboratory experiments we show that living oyster mushroomsPleurotus ostreatusexhibit mem-fractive properties. We offer a piece-wise polynomial approximation of theI-Vbehaviour of the oyster mushrooms. We also report spiking activity, oscillations in conduced current of the oyster mushrooms.

Projecting the effect of easing societal restrictions on non-COVID-19 emergency demand in the UK: Statistical inference using public mobility data

While it is well established that societal restrictions have been effective in reducing COVID-19 emergency demand, evidence also suggests an impact upon emergency demand not directly related to COVID-19 infection. Hospital planning may benefit from a greater understanding of this association and the ability to reliably forecast future levels of non-COVID-19 demand. Activity data for Accident and Emergency (A&E) attendances and emergency admissions were sourced for all hospitals within the Bristol, North Somerset and South Gloucestershire healthcare system. These were regressed upon publicly available mobility data obtained from Google's Community Mobility Reports for the local area. Seasonal trends were controlled for using time series decomposition. The models were used to predict non-COVID-19 emergency demand under the UK Government's plan to sequentially lift all restrictions by 21 June 2021, in addition to three alternative hypothetical relaxation strategies. Rates of public mobility within the local area were shown to account for 77% and 65% of the variance in non-COVID-19 related A&E attendances and emergency admissions respectively. Modelling supports an increase in emergency demand in line with the level and timing of societal restrictions, with significant increases to be expected upon the ending of all legal limits. This study finds that non-COVID-19 emergency demand associates with the level of societal restrictions, with rates of public mobility representing a key determinant. Through predictive modelling, healthcare systems can improve their demand forecasting in effectively managing hospital capacity.

Anterior thalamic nuclei, but not retrosplenial cortex, lesions abolish latent inhibition in rats

The present study examined the effects of excitotoxic lesions in 2 closely related structures, the anterior thalamic nuclei and the retrosplenial cortex, on latent inhibition. Latent inhibition occurs when nonreinforced preexposure to a stimulus retards the subsequent acquisition of conditioned responding to that stimulus. Latent inhibition was assessed in a within-subject procedure with auditory stimuli and food reinforcement. As expected, sham-operated animals were slower to acquire conditioned responding to a stimulus that had previously been experienced without consequence, relative to a non-preexposed stimulus. This latent inhibition effect was absent in rats with excitotoxic lesions in the anterior thalamic nuclei, as these animals conditioned to both stimuli at equivalent rates. The retrosplenial lesions appeared to spare latent inhibition, as these animals displayed a robust stimulus preexposure effect. The demonstration here that anterior thalamic nuclei lesions abolish latent inhibition is consistent with emerging evidence of the importance of these thalamic nuclei for attentional control. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

A One-Year Survey of Norovirus in UK Oysters Collected at the Point of Sale

Contamination of bivalve shellfish, particularly oysters, with norovirus is recognised as a food safety risk and a potential contributor to the overall burden of gastroenteritis in the community. The United Kingdom (UK) has comprehensive national baseline data on the prevalence, levels, and seasonality of norovirus in oysters in production areas resulting from a previous two-year study (2009-2011). However, previously, data on final product as sold to the consumer have been lacking. As part of a wider project to establish the overall burden of foodborne norovirus in the UK, this study aimed to address this data gap. A one-year survey of oysters collected from the point-of-sale to the consumer was carried out from March 2015 to March 2016. A total of 630 samples, originating in five different European Union Member States, were collected from 21 regions across the UK using a randomised sampling plan, and tested for norovirus using a method compliant with ISO 15216-1, in addition to Escherichia coli as the statutory indicator of hygiene status. As in the previous production area study, norovirus RNA was detected in a high proportion of samples (68.7%), with a strong winter seasonality noted. Some statistically significant differences in prevalences and levels in oysters from different countries were noted, with samples originating in the Netherlands showing lower prevalences and levels than those from either the UK or Ireland. Overall, levels detected in positive samples were considerably lower than seen previously. Investigation of potential contributing factors to this pattern of results was carried out. Application of normalisation factors to the data from the two studies based on both the numbers of norovirus illness reports received by national surveillance systems, and the national average environmental temperatures during the two study periods resulted in a much closer agreement between the two data sets, with the notably different numbers of illness reports making the major contribution to the differences observed in norovirus levels in oysters. The large majority of samples (76.5%) contained no detectable E. coli; however, in a small number of samples (2.4%) levels above the statutory end product standard (230 MPN/100 g) were detected. This study both revealed the high prevalence of norovirus RNA in oysters directly available to the UK consumer, despite the high level of compliance with the existing E. coli-based health standards, while also highlighting the difficulty in comparing the results of surveys carried out in different time periods, due to variability in risk factors.

Lesions of retrosplenial cortex spare immediate-early gene activity in related limbic regions in the rat

The retrosplenial cortex forms part of a network of cortical and subcortical structures that have particular importance for spatial learning and navigation in rodents. This study examined how retrosplenial lesions affect activity in this network by visualising the expression of the immediate-early genes c-fos and zif268 after exposure to a novel location. Groups of rats with extensive cytotoxic lesions (areas 29 and 30) and rats with lesions largely confined to area 30 (dysgranular cortex) were compared with their respective control animals for levels of c-fos expression measured by immunohistochemistry. These cortical lesions had very limited effects on distal c-fos activity. Evidence of a restricted reduction in c-fos activity was seen in the septal dentate gyrus (superior blade) but not in other hippocampal and parahippocampal subareas, nor in the anterior cingulate and prelimbic cortices. Related studies examined zif268 activity in those cases with combined area 29 and 30 lesions. The only clear evidence for reduced zif268 activity following retrosplenial cell loss came from the septal CA3 area. The confined impact of retrosplenial tissue loss is notable as, by the same immediate-early gene measures, retrosplenial cortex is itself highly sensitive to damage in related limbic areas, showing a marked c-fos and zif268 hypoactivity across all of its subareas. This asymmetry in covert pathology may help to explain the apparent disparity between the severity of learning deficits after retrosplenial cortex lesions and after lesions in either the hippocampus or the anterior thalamic nuclei.

The rat retrosplenial cortex as a link for frontal functions: A lesion analysis

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Retrosplenial cortex lesions do not reproduce the pattern of effects of medial frontal damage.

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Retrosplenial cortex lesions spare tests of behavioural flexibility.

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Effort-based decision making does not require the retrosplenial cortex.

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Reveals specific conditions when nonspatial tasks engage retrosplenial cortex.

Cohorts of rats with excitotoxic retrosplenial cortex lesions were tested on four behavioural tasks sensitive to dysfunctions in prelimbic cortex, anterior cingulate cortex, or both. In this way the study tested whether retrosplenial cortex has nonspatial functions that reflect its anatomical interactions with these frontal cortical areas. In Experiment 1, retrosplenial cortex lesions had no apparent effect on a set-shifting digging task that taxed intradimensional and extradimensional attention, as well as reversal learning. Likewise, retrosplenial cortex lesions did not impair a strategy shift task in an automated chamber, which involved switching from visual-based to response-based discriminations and, again, included a reversal (Experiment 2). Indeed, there was evidence that the retrosplenial lesions aided the initial switch to response-based selection. No lesion deficit was found on an automated cost-benefit task that pitted size of reward against effort to achieve that reward (Experiment 3). Finally, while retrosplenial cortex lesions affected matching-to-place task in a T-maze, the profile of deficits differed from that associated with prelimbic cortex damage (Experiment 4). When the task was switched to a nonmatching design, retrosplenial cortex lesions had no apparent effect on performance. The results from the four experiments show that many frontal tasks do not require the retrosplenial cortex, highlighting the specificity of their functional interactions. The results show how retrosplenial cortex lesions spare those learning tasks in which there is no mismatch between the internal and external representations used to guide behavioural choice. In addition, these experiments further highlight the importance of the retrosplenial cortex in solving tasks with a spatial component.

The retrosplenial cortex and object recency memory in the rat

It has been proposed that the retrosplenial cortex forms part of a ‘where/when’ information network. The present study focussed on the related issue of whether retrosplenial cortex also contributes to ‘what/when’ information, by examining object recency memory. In Experiment 1, rats with retrosplenial lesions were found to be impaired at distinguishing the temporal order of objects presented in a continuous series (‘Within‐Block’ condition). The same lesioned rats could, however, distinguish between objects that had been previously presented in one of two discrete blocks (‘Between‐Block’ condition). Experiment 2 used intact rats to map the expression of the immediate‐early gene c‐fos in retrosplenial cortex following performance of a between‐block, recency discrimination. Recency performance correlated positively with levels of c‐fos expression in both granular and dysgranular retrosplenial cortex (areas 29 and 30). Expression of c‐fos in the granular retrosplenial cortex also correlated with prelimbic cortex and ventral subiculum c‐fos activity, the latter also correlating with recency memory performance. The combined findings from both experiments reveal an involvement of the retrosplenial cortex in temporal order memory, which includes both between‐block and within‐block problems. The current findings also suggest that the rat retrosplenial cortex comprises one of a group of closely interlinked regions that enable recency memory, including the hippocampal formation, medial diencephalon and medial frontal cortex. In view of the well‐established importance of the retrosplenial cortex for spatial learning, the findings support the notion that, with its frontal and hippocampal connections, retrosplenial cortex has a key role for both what/when and where/when information.

Asymmetric cross-hemispheric connections link the rat anterior thalamic nuclei with the cortex and hippocampal formation

Dense reciprocal connections link the rat anterior thalamic nuclei with the prelimbic, anterior cingulate and retrosplenial cortices, as well as with the subiculum and postsubiculum. The present study compared the ipsilateral thalamic-cortical connections with the corresponding crossed, contralateral connections between these same sets of regions. All efferents from the anteromedial thalamic nucleus to the cortex, as well as those to the subiculum, remained ipsilateral. In contrast, all of these target sites provided reciprocal, bilateral projections to the anteromedial nucleus. While the anteroventral thalamic nucleus often shared this same asymmetric pattern of cortical connections, it received relatively fewer crossed inputs than the anteromedial nucleus. This difference was most marked for the anterior cingulate projections, as those to the anteroventral nucleus remained almost entirely ipsilateral. Unlike the anteromedial nucleus, the anteroventral nucleus also appeared to provide a restricted, crossed projection to the contralateral retrosplenial cortex. Meanwhile, the closely related laterodorsal thalamic nucleus had almost exclusively ipsilateral efferent and afferent cortical connections. Likewise, within the hippocampus, the postsubiculum seemingly had only ipsilateral efferent and afferent connections with the anterior thalamic and laterodorsal nuclei. While the bilateral cortical projections to the anterior thalamic nuclei originated predominantly from layer VI, the accompanying sparse projections from layer V largely gave rise to ipsilateral thalamic inputs. In testing a potentially unifying principle of anterior thalamic - cortical interactions, a slightly more individual pattern emerged that reinforces other evidence of functional differences within the anterior thalamic and also helps to explain the consequences of unilateral interventions involving these nuclei.

What does spatial alternation tell us about retrosplenial cortex function?

The retrosplenial cortex supports navigation, but there are good reasons to suppose that the retrosplenial cortex has a very different role in spatial memory from that of the hippocampus and anterior thalamic nuclei. For example, retrosplenial lesions appear to have little or no effect on standard tests of spatial alternation. To examine these differences, the current study sought to determine whether the retrosplenial cortex is important for just one spatial cue type (e.g., allocentric, directional or intra-maze cues) or whether the retrosplenial cortex helps the animal switch between competing spatial strategies or competing cue types. Using T-maze alternation, retrosplenial lesion rats were challenged with situations in which the available spatial information between the sample and test phases was changed, so taxing the interaction between different cue types. Clear lesion deficits emerged when intra- and extra-maze cues were placed in conflict (by rotating the maze between the sample and choice phases), or when the animals were tested in the dark in a double-maze. Finally, temporary inactivation of the retrosplenial cortex by muscimol infusions resulted in a striking deficit on standard T-maze alternation, indicating that, over time, other sites may be able to compensate for the loss of the retrosplenial cortex. This pattern of results is consistent with the impoverished use of both allocentric and directional information, exacerbated by an impaired ability to switch between different cue types.

Physiological effects of TGF(alpha)-PE40 expression in recombinant Escherichia coli JM109

Physiological effects of isopropyl-thiogalactopyranoside (IPTG) induction were examined in Escherichia coli strain JM109 expressing a fusion protein composed of transforming growth factor alpha and a 40-kD portion of Pseudomonas aeruginosa exotoxin A (TGF(alpha)-PE40) under control of the tac promoter. Fermentations at the 15-L scale in complex medium compared growth and metabolite profiles of the untransformed JM109 host strain, the strain transformed with the vector lacking the TGF(alpha)-PE40 open reading frame (JM109[pKK2.7]), and the strain with the complete plasmid for TGF(alpha)-PE40 expression (JM109[pTAC-TGF57-PE40]). Metabolite and growth profiles of JM109 (pTAC-TGF57-PE40) cultures changed significantly in IPTG-induced versus uninduced cultures. Prior to induction, glucose was metabolized to acetate or completely oxidized to CO(2). Following induction, pyruvate was also excreted in addition to acetate. In the absence of inducer, pyruvate was excreted by JM109 (pTAC-TGF57-PE40) only when dissolved oxygen levels fell to less than 10% of saturation (microaerobic rather than anaerobic conditions). The untransformed JM109 host strain or JM109 (pKK2.7) did not excrete pyruvate in the presence or absence of inducer, although JM109 (pKK2.7) exhibited a pattern of growth following addition of IPTG that closely resembled JM109 (pTAC-TFG57-PE40). Fermentations of JM109 (pTAC-TFG57-PE40) in a synthetic medium supported lower expression levels, but resulted in similar alterations in metabolite profiles. Induction in synthetic medium resulted in pyruvate excretion without further acetate accumulation. Taken together, these data suggest that one consequence of TGF(alpha)-PE40 expression in JM109 is altered patterns of pyruvate oxidation.

Transgenic expression of pear PGIP in tomato limits fungal colonization

Transgenic tomato plants expressing the pear fruit polygalacturonase inhibitor protein (pPGIP) were used to demonstrate that this inhibitor of fungal pathogen endopolygalacturonases (endo-PGs) influences disease development. Transgenic expression of pPGIP resulted in abundant accumulation of the heterologous protein in all tissues and did not alter the expression of an endogenous tomato fruit PGIP (tPGIP). The pPGIP protein was detected, as expected, in the cell wall protein fraction in all transgenic tissues. Despite differential glycosylation in vegetative and fruit tissues, the expressed pPGIP was active in both tissues as an inhibitor of endo-PGs from Botrytis cinerea. The growth of B. cinerea on ripe tomato fruit expressing pPGIP was reduced, and tissue breakdown was diminished by as much as 15%, compared with nontransgenic fruit In transgenic leaves, the expression of pPGIP reduced lesions of macerated tissue approximately 25%, a reduction of symptoms of fungal growth similar to that observed with a B. cinerea strain in which a single endo-PG gene, Bcpg1, had been deleted (A. ten Have, W. Mulder, J. Visser, and J. A. L. van Kan, Mol. Plant-Microbe Interact. 11:1009-1016, 1998). Heterologous expression of pPGIP has demonstrated that PGIP inhibition of fungal PGs slows the expansion of disease lesions and the associated tissue maceration.

An expansin gene expressed in ripening strawberry fruit

Tissue softening accompanies the ripening of many fruit and initiates the processes of irreversible deterioration. Expansins are plant cell wall proteins proposed to disrupt hydrogen bonds within the cell wall polymer matrix. Expression of specific expansin genes has been observed in tomato (Lycopersicon esculentum) meristems, expanding tissues, and ripening fruit. It has been proposed that a tomato ripening-regulated expansin might contribute to cell wall polymer disassembly and fruit softening by increasing the accessibility of specific cell wall polymers to hydrolase action. To assess whether ripening-regulated expansins are present in all ripening fruit, we examined expansin gene expression in strawberry (Fragaria x ananassa Duch.). Strawberry differs significantly from tomato in that the fruit is derived from receptacle rather than ovary tissue and strawberry is non-climacteric. A full-length cDNA encoding a ripening-regulated expansin, FaExp2, was isolated from strawberry fruit. The deduced amino acid sequence of FaExp2 is most closely related to an expansin expressed in early tomato development and to expansins expressed in apricot fruit rather than the previously identified tomato ripening-regulated expansin, LeExp1. Nearly all previously identified ripening-regulated genes in strawberry are negatively regulated by auxin. Surprisingly, FaExp2 expression was largely unaffected by auxin. Overall, our results suggest that expansins are a common component of ripening and that non-climacteric signals other than auxin may coordinate the onset of ripening in strawberry.

Attention deficit hyperactivity disorder associated with orbitofrontal epilepsy in a father and a son

The authors report on a father and son with frontal lobe epilepsy and symptoms of attention deficit hyperactivity disorder (ADHD). Attention deficit hyperactivity is a syndrome defined by criteria that include inattention, impulsive behavior, impaired concentration and motor restlessness. It does not require medical or neurobehavioral evaluation to determine an underlying etiology. The father is a 45-year-old man evaluated for possible ADHD. His referral came after the diagnosis of ADHD in his 6-year-old son who responded well to treatment with methylphenidate HCL. Neurobehavioral evaluation of the father suggested frontal lobe dysfunction. Magnetic resonance imaging and electroencephalography (EEG) were normal. Brain 99mTc HMPAO single-photon emission computed tomography (SPECT) revealed left orbitofrontal hypoperfusion. Additional history from his wife revealed episodic symptoms suggestive of nonconvulsive epilepsy that included nonresponsive staring, complex automatic behavior, and amnesic lacunas. Treatment of the father with carbmazepine produced dramatic improvement. Subsequent evaluation of his son, currently on maintenance treatment with methylphenidate HCL for ADHD, elicited a history consistent with atonic and simple motor partial epilepsy. The son's brain SPECT revealed bilateral orbitofrontal hypoperfusion defects. Attention deficit hyperactivity disorder is a syndrome that may be caused by frontal lobe lesions or epilepsy. In the setting of possible ADHD, neurological evaluation is warranted. Although overreliance on structural imaging or EEG in such an evaluation must be discouraged, brain SPECT may be useful to evaluate patients with symptoms of attention disorders for frontal epilepsy.

Emotions and cognitions associated with bingeing and weight control behavior in bulimia

The examination of cognitions and emotions during the bulimic cycle is critical in understanding possible maintenance factors involved in bulimia. In this study, 22 bulimics and 22 nonbulimics recorded their thoughts and feelings every 2 waking hours over a 6-day period. Bulimics additionally recorded their moods and thoughts during their binges and compensatory behaviors (e.g., purging, exercise). Higher levels of negative affect were reported at all stages of the cycle compared to baseline, although negative affect decreased after the compensatory behavior stage. Subjects also reported stronger distorted cognitions before and after the binge compared to baseline. One of the distorted cognitions (feeling fat) decreased in strength after subjects engaged in compensatory behavior. Additional analyses revealed that most levels of negative affect and distorted cognitions were elevated prior to binges as compared to meals. Finally, negative affect and distorted cognitions were stronger after binges than after meals.

The protective effects of education on simulated brain injury

Disturbed intellectual function is an important determinant of long-term recovery after head injury. Residual behavioral disability depends largely upon which hemisphere is damaged and the site of injury within the hemisphere. Resulting neurobehavioral syndromes vary with the pattern of brain insult. While this correlation is important, it is still not well understood how damage to single neurons translates into abnormal behavior. In addition, no currently available technology permits in vivo evaluation of such cells in normal or injured states. While research into brain trauma traditionally emphasize single cell pathology, this level of study is insufficient to clarify how individual cell activity contributes to higher cognition. In contrast, neural network simulations may partially fill this void by predicting biological function. Here, we present data generated by a three-layer neural network that employs the ALOPEX algorithm, capable of learning 10 words. The addition of Gaussian distributed noise into connection weights strengths damaged the network's function; interestingly, the rate and extent of network impairment depended upon the level of learning that occurred during the training period, in agreement with human studies that demonstrate a protective effect of education on subsequent brain injury. Damage to input signals resulted in similar effects on network function. Accordingly, such simulations offer powerful evidence that human behavior may be considered in terms of neuronal cell populations and efforts to preserve brain function at the time of injury should emphasize maintaining neural connections.

Structure and expression of an inhibitor of fungal polygalacturonases from tomato

A polygalacturonase inhibitor protein (PGIP) was characterized from tomato fruit. Differential glycosylation of a single polypeptide accounted for heterogeneity in concanavalin A binding and in molecular mass. Tomato PGIP had a native molecular mass of 35 to 41 kDa, a native isoelectric point of 9.0, and a chemically deglycosylated molecular mass of 34 kDa, suggesting shared structural similarities with pear fruit PGIP. When purified PGIPs from pear and tomato were compared, tomato PGIP was approximately twenty-fold less effective an inhibitor of polygalacturonase activity isolated from cultures of Botrytis cinerea. Based on partial amino acid sequence, polymerase chain reaction products and genomic clones were isolated and used to demonstrate the presence of PGIP mRNA in both immature and ripening fruit as well as cell suspension cultures. Nucleotide sequence analysis indicates that the gene, uninterrupted by introns, encodes a predicted 36.5 kDa polypeptide containing amino acid sequences determined from the purified protein and sharing 68% and 50% amino acid sequence identity with pear and bean PGIPs, respectively. Analysis of the PGIP sequences also revealed that they belong to a class of proteins which contain leucine-rich tandem repeats. Because these sequence domains have been associated with protein-protein interactions, it is possible that they contribute to the interaction between PGIP and fungal polygalacturonases.

Senile dementia of extreme aging: a common disorder of centenarians

To study dementia in the extremely aged, I evaluated 40 centenarians with a mean age of 101.6 years (range: 100-107). The group completed 5.8 years of education, on average. Bradyphrenia and bradykinesia were common and most had impaired awareness and concern. The Folstein Mini-Mental State Exam and Washington University's Clinical Dementia Rating Scale indicated moderately advanced dementia in more than half; 4 had a clinical pattern that suggested senile dementia of the Alzheimer's type. A common pattern of dementia emerged consisting of preserved awareness of the environment, normal participation in conversations, mild bradyphrenia and bradykinesia with normal latency to respond to questions and memory impairment with diminished ability to learn new information. They had a constricted universe with limited awareness of events outside their personal sphere; they repeated themes and topics endlessly. This study suggests senile dementia is common in centenarians.

Development of scale-down techniques for investigation of recombinant Escherichia coli fermentations: acid metabolites in shake flasks and stirred bioreactors

We have developed shake-flask screening conditions that are predictive of specific expression of the chimeric toxin, TGF alpha-PE40, by recombinant Escherichia coli JM109 in stirred bioreactors. When a nutrient-rich stirred bioreactor medium was used in shake flasks, neither the extent of growth nor the specific level of recombinant protein expression duplicated the performance in stirred bioreactor fermentations. Incomplete oxidation of glucose and concomitant accumulation of organic acid metabolites, as well as oxygen limitation and lack of pH control, were examined as contributors to the poorer performance in the flask. The medium buffering capacity, initial glucose level, and flask aeration were evaluated to establish the limits of "scale-down" conditions for expression both in a complex nutrient medium (M101) similar to that used in stirred bioreactors and in a defined (FM) medium. Acid metabolites and ethanol were measured as indicators of carbon flow from glucose as well as indirect indicators of oxygen limitation. For the complex M101 medium, optimal shake-flask performance in 250-mL, nonbaffled flasks at 37 degrees C occurred with 0.3 x medium strength, supplementation with 0.3 m HEPES buffer (pH 7.5), and 10 mL of medium per flask. Cultures grown under these conditions produced a maximum density of 3.6 g of dry cell weight/L (as estimated by absorbance measurements at 600 nm) and maintained a pH near neutrality. Additionally, metabolite markers of anaerobic or microaerobic conditions, such as ethanol, lactate, and pyruvate, were not detected, and specific expression of TGF alpha-PE40 was comparable to stirred bioreactors induced for expression at various biomass levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Convex third ventricle: a possible sign for dementia using MRI

The shape and thickness of the third ventricles were studied with magnetic resonance imaging in 46 patients under evaluation for memory impairment. We compared this population with 23 subjects imaged for other reasons. The study group consisted of patients with diagnoses of probable dementia of the Alzheimer's type (DAT; 35.6%), multi-infarct dementia (MID; 22.2%), depression (8.9%), alcoholic dementia (6.7%), other dementias (OD; 13.2%) and no dementia (6.7%). Within the study group, there were no significant differences across diagnostic categories for duration of symptoms or level of education. Patients with DAT were, however, more impaired than others (Mini-Mental State Examination scores: DAT 14.6 [+/- 8.2] versus MID 17.4 [+/- 6.2] versus OD 21.2 [+/- 6.4]). Demented subjects were more likely than nondemented individuals to have a convex third ventricle and greater wall separation. The results suggest that the shape of the third ventricle may correlate with dementia. Possibly, the dorsal medial nucleus of the thalamus is involved in the dementia.

Molecular characterization of a polygalacturonase inhibitor from Pyrus communis L. cv Bartlett

A polygalacturonase inhibitor glycoprotein with an apparent molecular mass of 43 kD was purified from pear (Pyrus communis L. cv Bartlett) fruit. Chemical deglycosylation of this protein decreased the molecular mass to 34 kD. Gas chromatographic analysis suggests that N-linked glycosylation accounts for the majority of sugar moieties. Partial amino acid sequence analysis of the purified polygalacturonase inhibitor protein provided information used to amplify a corresponding cDNA by polymerase chain reactions. Multiple cloned products of these reactions were sequenced and the same open reading frame was identified in all of the products. It encodes a 36.5-kD polypeptide containing the amino acid sequences determined by protein sequencing and predicts a putative signal sequence of 24 amino acids and seven potential N-glycosylation sites. The expression of polygalacturonase inhibitor is regulated in a tissue-specific manner. Activity and mRNA level were much higher in fruit than in flowers or leaves.

A retrospective study of syphilis seropositivity in a cohort of demented patients

A retrospective study of 376 patients with dementia was performed to determine the rate of syphilis seropositivity. Subjects were seen over a 2.5-year period and received medical, social, psychiatric, neurological, and laboratory evaluations. Mean age was 74 years and 73% were women. Diagnoses included Alzheimer's disease (AD; 29.8%), vascular dementia (VascD; 24.7%), combined AD/VascD (14.3%), and other diagnoses (31.2%). Dementia was moderately advanced with a mean Folstein Mini-Mental State Score of 16. Fluorescent treponemal antibody absorption tests (FA) were performed on 338 of the patients with 10.9% being reactive. Two of nine subjects with reactive FA's had reactive rapid plasma reagin tests.

Brain imaging techniques in the diagnosis of dementia

Various recently developed brain imaging techniques used to assist in the diagnosis of dementia are reviewed. The methods reviewed are x-ray computed tomography scan imaging, magnetic resonance imaging, positron emission tomography, and the older techniques of pneumoencephalography and radioisotope cisternography. It was concluded that while these techniques often offer excellent diagnostic information, none of them provides a definitive characteristic image for Alzheimer's disease.

Five studies testing two new egoistic alternatives to the empathy-altruism hypothesis

The empathy-altruism hypothesis claims that prosocial motivation associated with feeling empathy for a person in need is directed toward the ultimate goal of benefiting that person, not toward some subtle form of self-benefit. We explored two new egoistic alternatives to this hypothesis. The empathy-specific reward hypothesis proposes that the prosocial motivation associated with empathy is directed toward the goal of obtaining social or self-rewards (i.e., praise, honor, and pride). The empathy-specific punishment hypothesis proposes that this motivation is directed toward the goal of avoiding social or self-punishments (i.e., censure, guilt, and shame). Study 1 provided an initial test of the empathy-specific reward hypothesis. Studies 2 through 4 used three procedures to test the empathy-specific punishment hypothesis. In Study 5, a Stroop procedure was used to assess the role of reward-relevant, punishment-relevant, and victim-relevant cognitions in mediating the empathy-helping relationship. Results of these five studies did not support either the empathy-specific reward or the empathy-specific punishment hypothesis. Instead, results of each supported the empathy-altruism hypothesis. Evidence that empathic emotion evokes altruistic motivation continues to mount.

Speech and language alterations in multi-infarct dementia

Speech and language functions were assessed in 18 patients with multi-infarct dementia (MID) and 14 with dementia of the Alzheimer type (DAT). The age range and dementia severity of the two groups were comparable. We used a speech and language battery assessing 37 elements of verbal output to characterize alterations in the patients. MID patients had more abnormalities of motor aspects of speech, whereas DAT patients had empty speech, more marked anomia, and relative sparing of motor speech functions. The results demonstrate that speech and language differ in MID and DAT. In addition, MID patients exhibited common clinical features despite the heterogeneity of the syndrome.

Five studies testing two new egoistic alternatives to the empathy-altruism hypothesis

The empathy-altruism hypothesis claims that prosocial motivation associated with feeling empathy for a person in need is directed toward the ultimate goal of benefiting that person, not toward some subtle form of self-benefit. We explored two new egoistic alternatives to this hypothesis. The empathy-specific reward hypothesis proposes that the prosocial motivation associated with empathy is directed toward the goal of obtaining social or self-rewards (i.e., praise, honor, and pride). The empathy-specific punishment hypothesis proposes that this motivation is directed toward the goal of avoiding social or self-punishments (i.e., censure, guilt, and shame). Study 1 provided an initial test of the empathy-specific reward hypothesis. Studies 2 through 4 used three procedures to test the empathy-specific punishment hypothesis. In Study 5, a Stroop procedure was used to assess the role of reward-relevant, punishment-relevant, and victim-relevant cognitions in mediating the empathy-helping relationship. Results of these five studies did not support either the empathy-specific reward or the empathy-specific punishment hypothesis. Instead, results of each supported the empathy-altruism hypothesis. Evidence that empathic emotion evokes altruistic motivation continues to mount.

Lithium interaction with sulindac and naproxen

The interaction of lithium with sulindac and naproxen was studied in six sulindac-treated and seven naproxen-treated patients admitted to a geropsychiatry ward. Patients under a steady state lithium level received lithium for 3 days, then lithium + sulindac (300 mg/day) or naproxen (750 mg/day) for 6 days, and then lithium alone for 5 days. Sulindac failed to affect serum lithium levels and lithium clearance. The results with naproxen showed marked interindividual variations ranging from no increase to a 41.9% increase in serum lithium levels within 5 days. There was a corresponding decrease in lithium clearance in naproxen-treated patients. Patients undergoing lithium therapy might need a reduction of their lithium dosage following naproxen administration. More frequent serum lithium level determinations are required following initiation of naproxen therapy until the magnitude of the lithium-naproxen drug interaction can be adequately assessed in a given individual.

Failure of sulindac to increase serum lithium levels

The interaction of sulindac with lithium was investigated in four patients who were admitted to a geropsychiatry ward and required lithium therapy. Sulindac 300 mg/day failed to affect lithium serum level and renal lithium clearance in these patients. Sulindac seems safer in patients receiving lithium than drugs like indomethacin, which can substantially increase serum lithium levels.

Changes in T-DNA methylation and expression are associated with phenotypic variation and plant regeneration in a crown gall tumor line

Phenotypic variation of an octopine-type crown gall tumor line resulting from changes in the pattern of T-DNA methylation and expression is described. Variants that grow as unorganized callus always express T-DNA transcripts 1 and 2. In shoot-forming variants (teratomas) only T-DNA transcript 4 is expressed. This line also regenerates normal-appearing, rooted plants in which all T-DNA expression is suppressed. Tissues from these plants require phytohormones for growth in vitro. These plants are self-fertile and transmit T-DNA through meiosis, and T-DNA suppression is maintained in the next generation. After treatment of regenerated plant tissue with 5-azacytidine, an inhibitor of DNA methylation, T-DNA transcription and phytohormone-independent tumorous growth resume. The T-DNA of cell lines in which T-DNA is not expressed is highly methylated, whereas the level of T-DNA methylation is reduced in 5-azacytidine treated cells that resume T-DNA expression and phytohormone-independent growth. The correlation between the degree of T-DNA methylation and the level of T-DNA expression indicates that hypermethylation is responsible for the suppression of T-DNA transcription.

Immunopathological changes in cadmium-treated rats

Rats treated with cadmium developed an interstitial pneumonitis with intraalveolar hemorrhage. In the spleen there was marked germinal center formation containing reactive B-cells. Lesions of the kidneys resembled those found in cadmium poisoning in man, primarily a proliferative glomerulonephritis.

Epstein-Barr virus-specific RNA. III. Mapping of DNA encoding viral RNA in restringent infection

Namalwa and Raji cells, originally obtained from a Burkitt tumor biopsy, grow as continuous cell lines in vitro and contain the Epstein-Barr virus (EBV)-related nuclear antigen EBNA (B. M. Reedman and G. Klein, Int. J. Cancer 11:499-520, 1973) and RNA homologous to at least 17 and 30% of the EBV genome, respectively (S. D. Hayward and E. Kieff, J. Virol. 18:518-525, 1976; T. Orellana and E. Kieff, J. Virol. 22:321-330, 1977). The polyribosomal and polyadenylated [poly(A)+] RNA fractions of Namalwa and Raji cells are enriched for a class of viral RNA homologous to 5 to 7% of EBV DNA (Hayward and Kieff, J. Virol. 18:518-525, 1976; Orellana and Kieff, J. Virol. 22:321-330, 1977). The objective of the experiments described in this communication was to determine the location within the map of the EBV genome (D. Given and E. Kieff, J. Virol. 28:524-542, 1978) of the DNA which encodes the viral RNA in the poly(A)+ and non-polyadenylated [poly(A)-] RNA fractions of Namalwa cells. Hybridization of labeled DNA homologous to Namalwa poly(A)+ or poly(A)- RNA to blots containing EcoRI, Hsu I, or Hsu I/EcoRI double-cut fragments of EBV (B95-8) or (W91) DNA indicated that these RNAs are encoded by DNA contained primarily in the Hsu I A/EcoRI A and Hsu I B/EcoRI A fragments and, to a lesser extent, in other fragments of the EBV genome. Hybridizations of Namalwa poly(A)+ and poly(A)- RNA in solution to denatured labeled EcoRI A or B fragments, Hsu I A, B, or D fragments, and Hsu I A/EcoRI A or Bam I S fragments and of Raji polyribosomal poly(A)+ RNA to the EcoRI A fragment indicated that (i) Namalwa poly(A)+ RNA is encoded primarily by 6 x 10(5) daltons of a 2 x 10(6)-dalton segment of DNA, Bam I S, which is tandemly reiterated, approximately 10 times, in the Hsu I A/EcoRI A fragment and is encoded to a lesser extent by DNA in the Hsu I B, EcoRI B, and Hsu I D fragments. Raji polyribosomal poly(A)+ RNA is encoded by a similar fraction of the EcoRI A fragment as that which encodes Namalwa poly(A)+ RNA. (ii) The fraction of the Bam I S fragment homologous to Namalwa poly(A)- RNA is similar to the fraction homologous to Namalwa poly(A)+ RNA. However, Namalwa poly(A)- RNA is homologous to a larger fraction of the DNA in the Hsu I B, Hsu I D, and EcoRI B fragments.