Memory for individual items is related to nonreinforced preference change

It is commonly assumed that memories contribute to value-based decisions. Nevertheless, most theories of value-based decision-making do not account for memory influences on choice. Recently, new interest has emerged in the interactions between these two fundamental processes, mainly using reinforcement-based paradigms. Here, we aimed to study the role memory processes play in preference change following the nonreinforced cue-approach training (CAT) paradigm. In CAT, the mere association of cued items with a speeded motor response influences choices. Previous studies with this paradigm showed that a single training session induces a long-lasting effect of enhanced preferences for high-value trained stimuli, that is maintained for several months. We hypothesized that CAT increases memory of trained items, leading to enhanced accessibility of their positive associative memories and in turn to preference changes. In two preregistered experiments, we found evidence that memory is enhanced for trained items and that better memory is correlated with enhanced preferences at the individual item level, both immediately and 1 mo following CAT. Our findings suggest that memory plays a central role in value-based decision-making following CAT, even in the absence of external reinforcements. These findings contribute to new theories relating memory and value-based decision-making and set the groundwork for the implementation of novel nonreinforced behavioral interventions that lead to long-lasting behavioral change.

Brain volumetric changes in the general population following the COVID-19 outbreak and lockdown

The coronavirus disease 2019 (COVID-19) outbreak introduced unprecedented health-risks, as well as pressure on the economy, society, and psychological well-being due to the response to the outbreak. In a preregistered study, we hypothesized that the intense experience of the outbreak potentially induced stress-related brain modifications in the healthy population, not infected with the virus. We examined volumetric changes in 50 participants who underwent MRI scans before and after the COVID-19 outbreak and lockdown in Israel. Their scans were compared with those of 50 control participants who were scanned twice prior to the pandemic. Following COVID-19 outbreak and lockdown, the test group participants uniquely showed volumetric increases in bilateral amygdalae, putamen, and the anterior temporal cortices. Changes in the amygdalae diminished as time elapsed from lockdown relief, suggesting that the intense experience associated with the pandemic induced transient volumetric changes in brain regions commonly associated with stress and anxiety. The current work utilizes a rare opportunity for real-life natural experiment, showing evidence for brain plasticity following the COVID-19 global pandemic. These findings have broad implications, relevant both for the scientific community as well as the general public.

Enhanced Bottom-Up and Reduced Top-Down fMRI Activity Is Related to Long-Lasting Nonreinforced Behavioral Change

Behavioral change studies and interventions focus on self-control and external reinforcements to influence preferences. Cue-approach training (CAT) has been shown to induce preference changes lasting months by merely associating items with neutral cues and speeded responses. We utilized this paradigm to study neural representation of preferences and their modification without external reinforcements. We scanned 36 participants with fMRI during a novel passive viewing task before, after and 30 days following CAT. We preregistered the predictions that activity in memory, top-down attention, and value-processing regions will underlie preference modification. While most theories associate preferences with prefrontal regions, we found that “bottom-up” perceptual mechanisms were associated with immediate change, whereas reduced “top-down” parietal activity was related to long-term change. Activity in value-related prefrontal regions was enhanced immediately after CAT for trained items and 1 month after for all items. Our findings suggest a novel neural mechanism of preference representation and modification. We suggest that nonreinforced change of preferences occurs initially in perceptual representation of items, putatively leading to long-term changes in “top-down” processes. These findings offer implementation of bottom-up instead of top-down targeted interventions for long-lasting behavioral change.

Characterization of HIV risks in a Brazilian sickle cell disease population

BACKGROUND

A low prevalence of HIV in sickle cell disease (SCD) patients has been reported in the literature though mechanisms for this are not understood.

METHODS

HIV risk behaviors were compared between SCD cases and non-SCD controls using a self-administered audio computer-assisted self-interview. SCD cases were recruited from a multi-center SCD cohort established in Brazil; controls were recruited from SCD social contacts. Categorical variables were analyzed using Chi-Square or Fisher exact test. Continuous variables were compared using the Mann-Whitney U test.

RESULTS

There were 152 SCD cases and 154 age/location matched controls enrolled at three participating Brazilian centers during 2016-17. No significant differences in number of sexual partners (lifetime or previous 12 months), male-to-male sex partners or intravenous drug use were observed. Cases received more transfusions, surgeries, and acupuncture treatment.

CONCLUSIONS

Besides the risk of transfusion-transmitted HIV, which is now exceedingly rare, SCD and non-SCD participants demonstrated similar HIV risk behaviors. Causes other than risk behaviors such as factors inherent to SCD pathophysiology may explain the reported low prevalence of HIV in SCD.

Enhanced striatal and prefrontal activity is associated with individual differences in nonreinforced preference change for faces

Developing effective preference modification paradigms is crucial to improve the quality of life in a wide range of behaviors. The cue‐approach training (CAT) paradigm has been introduced as an effective tool to modify preferences lasting months, without external reinforcements, using the mere association of images with a cue and a speeded button response. In the current work for the first time, we used fMRI with faces as stimuli in the CAT paradigm, focusing on face‐selective brain regions. We found a behavioral change effect of CAT with faces immediately and 1‐month after training, however face‐selective regions were not indicative of behavioral change and thus preference change is less likely to rely on face processing brain regions. Nevertheless, we found that during training, fMRI activations in the ventral striatum were correlated with individual preference change. We also found a correlation between preference change and activations in the ventromedial prefrontal cortex during the binary choice phase. Functional connectivity among striatum, prefrontal regions, and high‐level visual regions was also related to individual preference change. Our work sheds new light on the involvement of neural mechanisms in the process of valuation. This could lead to development of novel real‐world interventions.

The Cue-Approach Task as a General Mechanism for Long-Term Non-Reinforced Behavioral Change

Recent findings show that preferences for food items can be modified without external reinforcements using the cue-approach task. In the task, the mere association of food item images with a neutral auditory cue and a speeded button press, resulted in enhanced preferences for the associated stimuli. In a series of 10 independent samples with a total of 255 participants, we show for the first time that using this non-reinforced method we can enhance preferences for faces, fractals and affective images, as well as snack foods, using auditory, visual and even aversive cues. This change was highly durable in follow-up sessions performed one to six months after training. Preferences were successfully enhanced for all conditions, except for negative valence items. These findings promote our understanding of non-reinforced change, suggest a boundary condition for the effect and lay the foundation for development of novel applications.

Determining the health-related quality of life in individuals with haemophilia in developing economies: results from the Brazilian population

INTRODUCTION

Several studies show the negative impact of haemophilia in health-related quality of life (HRQOL). This issue is not well explored in developing countries.

OBJECTIVES

This cross-sectional study aimed to evaluate the HRQOL and its associated factors in patients with haemophilia A/B in Brazil. Data were collected by questionnaire and in medical records, including a Portuguese version of Haem-A-Qol.

RESULTS

Brazilian patients were invited to the study and 175 participants (147 haemophilics A and 28 haemophilics B) were included. The total score of the Haem-A-QoL had a median of 36.96 (range of 0-100), with worse performance in 'sport and leisure' and best on 'relationships' fields. HRQOL was worst among the older participants, the less educated, non-white, non-working, who were hospitalized in the last year, who did not have a single medical consultation and among those with the highest number of affected joints. Moreover, patients with hepatitis B had a significantly worse HRQOL in the domain 'sports and leisure', also observed in married patients. Otherwise, married individuals reported better HRQOL on 'dealing with the disease' domain. Patients with haemophilia B reported worse HRQOL in the domain 'self-perception'.

CONCLUSION

The results obtained could be helpful in guidance of haemophilia treatment which is determinant to improve HRQoL of the most vulnerable groups of patients. This work also reinforced the relevance of joint bleeds in all aspects of HRQoL in haemophilic patients. The use of prophylactic factor concentrates and multidisciplinary treatments could contribute to improve the quality of life in haemophilia.

[Outcome evaluation of a health promotion among the elderly]

The programme "active health promotion in old age" focuses on responsible self determination in old age (empowerment) and places special emphasis on physical activity and nutrition. The intervention, successfully conducted in an urban setting (Hamburg), was tested in a rural area (Kinzigtal, Baden-Wuerttemberg). In this paper we present the results of the outcome evaluation. The intervention group consisted of older people, without care need and without cognitive impairment who lived in their own home (N=468). For the evaluation of the results a pre-post comparison was conducted (2 measuring points within an interval of 12 months). 4 out of 5 participants reported changes in their behaviour after the intervention. However, the pre-post comparison shows significant changes only for nutrition behaviour, but not of physical activity. Health related quality of life (SF-36) did not change after 12 months. These findings indicate that health promotion in old age may lead to changes in nutrition behaviour.

[Active health promotion among the aged in a rural region. Participants, acceptance, and implementation]

The program "active health promotion in old age" focuses on persons aged 60 years and older who are not in need of care and are living independently without cognitive impairment. The objective of the intervention is to improve physical activity, healthy nutrition, and the integration of older people into network structures. The intervention was successfully conducted in an urban setting and has now been transferred to a rural area in southwestern Germany (Baden-Wuerttemberg). It was offered to statutory health insured people of Baden-Wuerttemberg within an integrated care program and was free of charge. This article reports the results of the process evaluation. For data collection, participants were interviewed using a standardized questionnaire. Semistructured interviews were conducted with the intervention team and involved general practitioners. In addition, secondary data were used to analyze selection bias between participants and nonparticipants. Although the rural area has a major impact on recruitment, access, and factors of implementation, results demonstrate that the intervention is highly accepted by participants. Moreover, structural conditions (e.g., fitness clubs, exercise classes) are essential for a successful transfer.

[Experience with the linkage of primary and secondary claims data in an intervention trial]

The data linkage of health-related primary and secondary data provides new opportunities for health services research. The advantages of both data sources can be used synergistically, in this way their disadvantages can be overcome. In the context of the evaluation of a health intervention - the integrated health services project ('Gesundes Kinzigtal') - the conditions and requirements for an individualised data linkage of primary data (survey) and claims data of a statutory health insurance are described in this paper. The integration of secondary data permits us not only to assess the intervention concerning physical activity, nutrition and social participation of elderly people ('AGil') but, above all, also to measure and analyse the program effects on the utilisation of health care services. Recommendations regarding the data linkage of primary and secondary data in health services research are derived from the results and experiences of the AGil study. Suggestions are made concerning the suitable pseudonymisation algorithm for primary and secondary data, the matching method, approaches to reduce mismatching and their validation, as well as the legal basis for such a data linkage. Overall, an individualised data linkage of primary and secondary data does not pose any technical problems. Nevertheless a couple of data protection rules have to be followed; the data linkage offers a high knowledge insight to many health and epidemiological research questions and might be the new gold standard for health services research.

Onconase, an anti-tumor ribonuclease suppresses intracellular oxidative stress

Onconase (ONC), an antitumor ribonuclease from oocytes of a frog Rana pipiens, capable of inducing apoptosis in many cell lines is synergistic with several other anticancer drugs. Since cytotoxic effects of numerous drugs are modulated by reactive oxygen intermediates (ROI), we have studied effects of ONC on the intracellular level of oxidants in several normal cell types as well as tumor cell lines. It is demonstrated for the first time that ONC substantially decreases the content of ROI in all cell lines studied. This effect depends on the ribonucleolytic activity of the enzyme and is due to both, decreased rate of ROI generation and accelerated rate of their degradation. Onconase decreases the mitochondrial transmembrane potential and consequently, generation of ATP. Simultaneously the enzyme decreases the expression of an antiapoptotic protein Bcl-2, and upregulates the proapoptotic Bax protein. These finding are consistent with the enzyme propensity to induce apoptosis. The observed antioxidant activity of ONC may be an important element of its cytotoxicity towards cancer cells. The enzyme seems to exert its biological activities by interfering with the redox system of cellular regulation.

Malignancy: A New Approach to the Analysis of Apoptosis in the Leukemic Subpopulation by Flow Cytometry Using a CD45 Gating Strategy

Bone marrow and peripheral blood are heterogeneous tissues containing cells of different hematopoietic lineages. It is possible to detect leukemic cells by flow cytometry using a gating strategy, which combines CD45 expression on the cell surface with right angle light scatter (SS). This approach was applied to 15 cases of AML. Myeloblasts had the lowest CD45 fluorescence intensity of any of the cells in the myeloid series and also had the lowest SS, approximately equivalent to monocytes, but greater than lymphoblasts and lymphocytes. Using this gating strategy in each sample we could identify up to 5 separate cell compartments. Our results showed good correlation between the flow differential and the manual differential cell count. However in some cases, especially when a sample became hypocellular, the flow differential was more sensitive in identifying leukemic blasts. Total apoptosis (i.e. apoptosis in all cell populations combined) varied during the treatment between 0-34%. In the blood, the highest percentage of total apoptotic cells usually occurred between day 3-5 of treatment. The percentage of apoptotic cells varied depending on the cell type on a percentage basis. The leukemic population was lesslikely to undergo apoptosis compared to the lymphocytes, monocytes and more mature myeloid cells. In normal cells, apoptosis occurred mostly in G(1) and S phases of the cell cycle. Apoptosis among CD45-blasts usually varied between 0-5%. Myeloblasts also had a tendency to undergo apoptosis in G(1) and S phases of the cell cycle. The CD45-blast apoptotic peak in the blood occurred between day 5-7 of treatment. Analysis of drug-induced apoptosis in bone marrow seems to provide more information than such measurements in peripheral blood.

High affinity binding of fluorescein isothiocyanate to eosinophils detected by laser scanning cytometry: a potential source of error in analysis of blood samples utilizing fluorescein-conjugated reagents in flow cytometry

BACKGROUND

In samples of peripheral blood cells processed using the commercial kits for detection of apoptosis based on DNA strand break labeling, a subpopulation of cells characterized by high green fluorescence, similar in intensity to that of apoptotic cells but more uniform, was consistently observed by flow cytometry. The labeled cells had no other features of apoptosis. The labeling was observed regardless of the fixative used and was evident in control samples lacking terminal deoxynucleotidyltransferase. Common to all the kits that generated this labeling pattern was the presence of fluorescein (f) conjugated reagents, f-dUTP, f-avidin, or f-antibody.

METHODS

Laser scanning cytometry was used to identify the labeled cells and study the mechanism of labeling. Because it was suspected that the traces of unconjugated f-isothiocyanate (FITC) that may contaminate the reagents were responsible for the labeling, FITC binding affinity to white blood cells was studied. Gel electrophoresis was used to detect the presence of unconjugated FITC in the reagents.

RESULTS

After staining with Giemsa, the strongly fluorescent objects were identified as eosinophils with normal morphology and no evidence of apoptosis. The fluorescence was localized exclusively within the cytoplasmic granules. Labeling of eosinophils was observed at 2 nM concentration of FITC, which was over three orders of magnitude lower than that needed to label neutrophils, monocytes, or lymphocytes. Gel electrophoresis of the f-conjugated reagents revealed only minor contamination with FITC.

CONCLUSIONS

(1) Trace amounts of unconjugated FITC contaminating the reagents are adequate to strongly label eosinophils thereby introducing experimental bias in analysis of apoptosis and in other studies on blood cells utilizing f-labeled antibodies, e.g., in detecting cytokines. (2) FITC at concentration 2-500 nM can be used as a marker of eosinophiles; (3) Because of high affinity to FITC, eosinophiles (or the protein from these cells) may serve as a means of removing traces of unconjugated FITC from the reagents during their manufacture or prior to use.