Associations of evening-type and insomnia symptoms with depressive symptoms among youths

BACKGROUND

Evening-type and insomnia symptoms are significantly related to each other and independently associated with depressive symptoms, yet few studies have examined the potential interaction between these two conditions. Therefore, we aimed to examine the associations of evening-type and insomnia symptoms with depressive symptoms among Chinese youths, with a specific focus on the joint effects of the two conditions on depressive symptoms.

METHODS

Participants aged between 12 and 25 were invited to participate in an online survey from December 15, 2022, to May 26, 2023. Multivariate logistic regression models and additive interaction models were used to examine the independent and joint effects of chronotypes and insomnia symptoms on depressive symptoms, respectively.

RESULTS

Of the 6145 eligible youths, the prevalence of evening-type and insomnia symptoms were 24.9 % and 29.6 %, respectively. Both evening-type (adjusted OR, [AdjOR]: 3.21, 95 % CI: 2.80-3.67) and insomnia symptoms (AdjOR: 10.53, 95 % CI: 9.14-12.12) were associated with an increased risk of depressive symptoms. In addition, the additive interaction models showed that there is an enhanced risk of depression related to interaction between evening-type and insomnia symptoms (relative excess risk due to interaction, [RERI]: 11.66, 95 % CI: 7.21-16.11).

CONCLUSIONS

The present study provided additional evidence demonstrating the presence of interaction between evening-type and insomnia symptoms, which can lead to a higher risk of depressive symptoms. Our findings argue the need for addressing both sleep and circadian factors in the management of depressive symptoms in young people.

Altered topology of individual brain structural covariance networks in major depressive disorder

BACKGROUND

The neurobiological pathogenesis of major depression disorder (MDD) remains largely controversial. Previous literatures with limited sample size utilizing group-level structural covariance networks (SCN) commonly generated mixed findings regarding the topology of brain networks.

METHODS

We analyzed T1 images from a high-powered multisite sample including 1173 patients with MDD and 1019 healthy controls (HCs). We used regional gray matter volume to construct individual SCN by utilizing a novel approach based on the interregional effect size difference. We further investigated MDD-related structural connectivity alterations using topological metrics.

RESULTS

Compared to HCs, the MDD patients showed a shift toward randomization characterized by increased integration. Further subgroup analysis of patients in different stages revealed this randomization pattern was also observed in patients with recurrent MDD, while the first-episode drug naïve patients exhibited decreased segregation. Altered nodal properties in several brain regions which have a key role in both emotion regulation and executive control were also found in MDD patients compared with HCs. The abnormalities in inferior temporal gyrus were not influenced by any specific site. Moreover, antidepressants increased nodal efficiency in the anterior ventromedial prefrontal cortex.

CONCLUSIONS

The MDD patients at different stages exhibit distinct patterns of randomization in their brain networks, with increased integration during illness progression. These findings provide valuable insights into the disruption in structural brain networks that occurs in patients with MDD and might be useful to guide future therapeutic interventions.

Dendritic spine dynamics in associative memory: A comprehensive review

Associative learning and memory are fundamental behavioral processes through which organisms adapt to complex environments. Associative memory involves long-lasting changes in synaptic plasticity. Dendritic spines are tiny protrusions from the dendritic shaft of principal neurons, providing the structural basis for synaptic plasticity and brain networks in response to external stimuli. Mounting evidence indicates that dendritic spine dynamics are crucial in different associative memory phases, including acquisition, consolidation, and reconsolidation. Causally bridging dendritic spine dynamics and associative memory is still limited by the suitable tools to measure and control spine dynamics in vivo under behaviorally relevant conditions. Here, we review data providing evidence for the remodeling of dendritic spines during associative memory processing and outline open questions.

Leisure Activities and the Risk of Dementia: A Systematic Review and Meta-analysis

BACKGROUND AND OBJECTIVES

Leisure activities are major components of modifiable and healthy lifestyles and are proposed to help prevent the development of dementia. This study aimed to assess the effects of different types of leisure activities, including cognitive, physical, and social activities, on the incidence of all-cause dementia (ACD), Alzheimer disease (AD), and vascular dementia (VD).

METHODS

We performed a systematic review and meta-analysis of the Cochrane, PubMed, Embase, and Web of Science databases to identify longitudinal studies that examined associations between leisure activities and dementia. Relative risks (RRs) and 95% CIs were pooled using random-effects meta-analysis. Subgroup analyses were used to estimate potential effect modifiers. The study was registered with PROSPERO (CRD42019116857).

RESULTS

A total of 38 longitudinal studies, with 2,154,818 participants at baseline, 74,700 ACD cases, 2,848 AD cases, and 1,423 VD cases during follow-up, were included in the meta-analysis. The subgroup analyses showed that physical (RR 0.83, 95% CI 0.78-0.88), cognitive (RR 0.77; 95% CI 0.68-0.87), and social (RR 0.93; 95% CI 0.87-0.99) activities were associated with a decreased incidence of ACD. In addition, physical (RR 0.87; 95% CI 0.78-0.96) and cognitive (RR 0.66; 95% CI 0.52-0.85) activities were related to a reduced risk of AD. Physical activity (RR 0.67; 95% CI 0.53-0.85) was associated with a lower incidence of VD.

DISCUSSION

Our findings suggest that leisure activities are inversely associated with a risk of ACD, AD, and VD.

COVID-19 Induced Economic Slowdown and Mental Health Issues

The COVID-19 pandemic has pressed a pause button on global economic development, and induced significant mental health problems. In order to demonstrate the progressed relationship between the pandemic, economic slowdown, and mental health burden, we overviewed the global-level gross domestic product changes and mental problems variation since the outbreak of COVID-19, and reviewed comprehensively the specific sectors influenced by the pandemic, including international trade, worldwide travel, education system, healthcare system, and individual employment. We hope to provide timely evidence to help with the promotion of policymakers’ effective strategies in mitigating economic losses induced by the pandemic; we suggest different governments or policy makers in different countries to share information and experience in dealing with COVID-19-induced economic slowdown and promote COVID-19 vaccine popularization plan to protect every individual worldwide against the coronavirus essentially; and we appeal international information share and collaboration to minimize stigmatization related to adverse mental consequences of COVID-19 and to increase mental health wellbeings of people all over the world.

Effects of COVID-19 on career and specialty choices among Chinese medical students

Coronavirus disease 2019 (COVID-19) pandemic has brought unprecedented challenges to medical education systems and medical students. The aim of this study was to investigate the effects of COVID-19 pandemic on medical career and specialty choices among medical students. An online cross-sectional survey of Chinese medical students was conducted during the COVID-19 pandemic from February to April 2020. The students' willingness to be a doctor before and after the COVID-19 pandemic and changed willingness to specialize in respiratory medicine and infectious diseases were investigated. Multiple linear regression and binary logistic regression was used to explore factors that were associated with changes of willingness. A total of 1,837 medical students, including 1,227 females (66.8%), with a median age of 21.0 years, were recruited. Of the participants, 10.6% and 6.9% showed increased and decreased willingness to be a doctor after the COVID-19 outbreak, respectively. Moreover, 11.7% showed increased willingness and 9.5% showed decreased willingness to major in respiratory medicine and infectious diseases. Students with younger age, lower household income, fewer depressive symptoms, less exposure to negative pandemic information and more satisfaction with their own major after the pandemic were associated with increased willingness to be a doctor. Students who engaged in regular exercise, were males and undergraduate level, were interested in medicine, paid more attention to positive information, were satisfied with their majors, and had increased willingness to be a doctor after the pandemic were more likely to choose to specialize in respiratory medicine and infectious disease. However, the severity of anxiety symptoms was associated with decreased willingness to work in the specialties of respiratory medicine and infectious diseases. Psychological problems and professional satisfaction appear to be independent factors that affect medial career and specialty choices. The impacts of the COVID-19 pandemic on medical students require further research.

Neural substrates of propranolol-induced impairments in the reconsolidation of nicotine-associated memories in smokers

The majority of smokers relapse even after successfully quitting because of the craving to smoking after unexpectedly re-exposed to smoking-related cues. This conditioned craving is mediated by reward memories that are frequently experienced and stubbornly resistant to treatment. Reconsolidation theory posits that well-consolidated memories are destabilized after retrieval, and this process renders memories labile and vulnerable to amnestic intervention. This study tests the retrieval reconsolidation procedure to decrease nicotine craving among people who smoke. In this study, 52 male smokers received a single dose of propranolol (n = 27) or placebo (n = 25) before the reactivation of nicotine-associated memories to impair the reconsolidation process. Craving for smoking and neural activity in response to smoking-related cues served as primary outcomes. Functional magnetic resonance imaging was performed during the memory reconsolidation process. The disruption of reconsolidation by propranolol decreased craving for smoking. Reactivity of the postcentral gyrus in response to smoking-related cues also decreased in the propranolol group after the reconsolidation manipulation. Functional connectivity between the hippocampus and striatum was higher during memory reconsolidation in the propranolol group. Furthermore, the increase in coupling between the hippocampus and striatum positively correlated with the decrease in craving after the reconsolidation manipulation in the propranolol group. Propranolol administration before memory reactivation disrupted the reconsolidation of smoking-related memories in smokers by mediating brain regions that are involved in memory and reward processing. These findings demonstrate the noradrenergic regulation of memory reconsolidation in humans and suggest that adjunct propranolol administration can facilitate the treatment of nicotine dependence. The present study was pre-registered at ClinicalTrials.gov (registration no. ChiCTR1900024412).

Prevalence and Risk Factors of Mental Health Symptoms and Suicidal Behavior Among University Students in Wuhan, China During the COVID-19 Pandemic

Background: University students who are exposed to coronavirus disease 2019 (COVID-19) could be mentally distressed. We aimed to evaluate the pattern and risk factors of mental health and suicidal behavior among students who experienced long-term school closure due to the COVID-19 pandemic. Methods: This large-sample, cross-sectional, online survey was conducted from June 29, 2020, to July 18, 2020. Eleven thousand two hundred fifty four participants were recruited from 30 universities located in Wuhan, Hubei Province, China. The prevalence of symptoms of depression, anxiety, insomnia, and posttraumatic stress disorder (PTSD) and suicidal behavior was evaluated using the Patient Health Questionnaire-9, Generalized Anxiety Disorder-7, Insomnia Severity Index, Posttraumatic Stress Disorder Checklist for DSM-5, and questions about suicidal ideation and attempts, respectively. Logistic regression was used to explore risk factors for mental health problems and suicidal behavior. Results: The prevalence of mental health problems was 41.5% for depressive symptoms, 32.6% for anxiety symptoms, 35.0% for insomnia symptoms, 8.5% for PTSD symptoms, and 2.0% for suicidal behavior. Participants with high stress during the pandemic were at higher risk of symptoms of depression [adjusted odds ratio (OR) = 1.67, 95% confidence interval (CI) = 1.43-1.95, p < 0.01), anxiety (adjusted OR = 1.90, 95% CI = 1.63-2.23, p < 0.01), insomnia (adjusted OR = 1.64, 95% CI = 1.44-1.87, p < 0.01), PTSD (adjusted OR = 1.71, 95% CI = 1.38-2.11, p < 0.01) and suicidal behavior (adjusted OR = 3.51, 95% CI = 2.28-5.40, p < 0.01). Distant relationship with parents, changes in lifestyle and alcohol use during the pandemic were associated with higher risk of mental health symptoms and suicidal behavior, whereas regular physical exercise reduced the risk of mental health problems. Conclusions: The psychological symptoms and suicidal behavior were relatively high among students who attended university in Wuhan, China after 6 months of the COVID-19 outbreak in China. Comprehensive mental health services and suicide prevention strategies are essential for university students during the COVID-19 pandemic.

Association of Symptoms of Attention Deficit and Hyperactivity with Problematic Internet Use among University Students in Wuhan, China During the COVID-19 Pandemic

BACKGROUND

COVID-19 is still spreading worldwide and posing a threat to individuals' physical and mental health including problematic internet use (PIU). A potentially high-risk group for PIU are those with symptoms of attention deficit and hyperactivity (ADHD symptoms), because of restrictions in their physical activity levels and engagement in computer diversions requiring only short attention spans.

METHODS

We used convenience sampling in a cross-sectional survey of university students from 30 universities in Wuhan, Hubei Province, China. We assessed PIU using the Internet Addiction Test and ADHD symptoms using the WHO Adult ADHD Self-Report Screening Scale. Using logistic regression and linear regression analyses we adjusted for demographic, epidemic-related and psychological covariates in models of the association between ADHD symptoms and PIU.

RESULTS

Among 11,254 participants, we found a 28.4% (95% CI, 27.5%-29.2%) prevalence of PIU, relatively higher than before the pandemic. In our final logistic regression model, participants with ADHD symptoms had approximately two times the risk for PIU (OR: 2.31, 95% CI: 1.89-2.83). Similarly, individuals with depression, anxiety, insomnia, PTSD symptoms and feeling stress during the pandemic had a higher risk of PIU, while those exercising regularly during the pandemic had a lower risk.

LIMITATIONS

The cross-sectional design and reliance on internet based self-reports for ADHD symptoms and PIU assessments, without direct structured interviews for validation, are limitations.

CONCLUSIONS

The prevalence of PIU was high during COVID-19, and those people with ADHD symptoms and other mental illness symptoms appear to be at higher risk of PIU. Regular exercise may reduce that PIU risk and hence should be recommended during the COVID-19 pandemic.

The impact of quarantine on mental health status among general population in China during the COVID-19 pandemic

Quarantine and isolation measures urgently adopted to control the COVID-19 pandemic might potentially have negative psychological and social effects. We conducted this cross-sectional, nationwide study to ascertain the psychological effect of quarantine and identify factors associated with mental health outcomes among population quarantined to further inform interventions of mitigating mental health risk especially for vulnerable groups under pandemic conditions. Sociodemographic data, attitudes toward the COVID-19, and mental health measurements of 56,679 participants from 34 provinces in China were collected by an online survey from February 28 to March 11, 2020. Of the 56,679 participants included in the study (mean [SD] age, 36.0 [8.2] years), 27,149 (47.9%) were male and 16,454 (29.0%) ever experienced home confinement or centralized quarantine during COVID-19 outbreak. Compared those without quarantine and adjusted for potential confounders, quarantine measures were associated with increased risk of total psychological outcomes (prevalence, 34.1% vs 27.3%; odds ratio [OR], 1.34; 95% CI, 1.28-1.39; P < 0.001). Multivariable logistic regression analyses showed that vulnerable groups of the quarantined population included those with pre-existing mental disorders or chronic physical diseases, frontline workers, those in the most severely affected areas during outbreak, infected or suspected patients, and those who are less financially well-off. Complying with quarantine, being able to take part in usual work, and having adequate understanding of information related to the outbreak were associated with less mental health issues. These results suggest that quarantine measures during COVID-19 pandemic are associated with increased risk of experiencing mental health burden, especially for vulnerable groups. Further study is needed to establish interventions to reduce mental health consequences of quarantine and empower wellbeing especially in vulnerable groups under pandemic conditions.

Propranolol-induced inhibition of unconditioned stimulus-reactivated fear memory prevents the return of fear in humans

Fear memories can be reactivated by a fear-associated conditioned stimulus (CS) or unconditioned stimulus (US) and then undergo reconsolidation. Propranolol administration during CS retrieval-induced reconsolidation can impair fear memory that is specific to the reactivated CS. However, from a practical perspective, the US is often associated with multiple CSs, and each CS can induce a fear response. The present study sought to develop and test a US-based memory retrieval interference procedure with propranolol to disrupt the original fear memory and eliminate all CS-associated fear responses in humans. We recruited 127 young healthy volunteers and conducted three experiments. All of the subjects acquired fear conditioning, after which they received the β-adrenergic receptor antagonist propranolol (40 mg) or placebo (vitamin C) and were exposed to the US or CS to reactivate the original fear memory. Fear responses were measured. Oral propranolol administration 1 h before US retrieval significantly decreased subsequent fear responses and disrupted associations between all CSs and the US. However, propranolol administration before CS retrieval only inhibited the fear memory that was related to the reactivated CS. Moreover, the propranolol-induced inhibition of fear memory reconsolidation that was retrieved by the US had a relatively long-lasting effect (at least 2 weeks) and was also effective for remote fear memory. These findings indicate that the US-based memory retrieval interference procedure with propranolol can permanently decrease the fear response and prevent the return of fear for all CSs in humans. This procedure may open new avenues for treating fear-related disorders.

Online Survey on Accessing Psychological Knowledge and Interventions During the COVID-19 Pandemic - China, 2020

What is already known on this topic?

The public was at elevated risk of mental health illnesses during the coronavirus disease 2019 (COVID-19) pandemic, so accessibility to psychological knowledge and interventions is vital to promptly respond to mental health crises.

What is added by this report?

During the pandemic period, 40,724 (71.9%) participants reportedly had access to psychological knowledge, and 36,546 (64.5%) participants had accessed information on psychological interventions. Participants who were male, unmarried, living alone, divorced or widowed, or infected with COVID-19 were less likely to access psychological knowledge and intervention.

What are the implications for public health practice?

Governments should pay more attention to formulate policies, popularize psychological education, and provide mental health services online or in the community.

Raising awareness of suicide prevention during the COVID-19 pandemic

Suicide is one of the top 20 leading causes of death worldwide. With the rapid spreading of coronavirus disease 2019 (COVID‐19) crisis around the world, suicide cases induced by the COVID‐19 pandemic have been reported in many countries. Individuals with suspected and confirmed COVID‐19 infection, frontline healthcare workers, bereaved families, elders, children, and adolescents are vulnerable populations who might be at elevated suicide risk. In this micro‐review, a systematic search through PubMed was performed for a comprehensive investigation of suicide risk factors during the pandemic. On this basis, we put forward considerations and advice for preventing pandemic related suicide, including staying socially connected through online platform or apps during period of quarantine, reducing unemployment, dispelling rumors and misinformation in time, and maintaining evidenced‐based management of psychiatric symptoms. More importantly, early detection and timely intervention of individuals with psychiatric disorders and suicide behaviors will be effective to reduce the number of suicides, with specific measurements of using validated scales to perform regular suicide risk screening, improving the availability of mental health services, and providing appropriate and evidence‐based interventions for individuals in demand. Policy makers, psychiatrists, psychologists, and other healthcare professionals need to collaborate to control the possible suicide events during the COVID‐19 pandemic and future possible crisis.

Individuals who are exposed to bio‐disaster might encounter increased suicide risk. Investigation of infectious disease‐related risk factors would facilitate suicide prevention. Early detection and timely intervention can be key and effective way to reduce suicide cases.

Psychological impact of the COVID-19 pandemic on healthcare workers: a cross-sectional study in China

BACKGROUND

Healthcare workers fighting against the coronavirus disease 2019 (COVID-19) pandemic are under tremendous pressure, which puts them at an increased risk of developing psychological problems.

AIMS

This study aimed to investigate the prevalence of psychological problems in different healthcare workers (ie, physicians, medical residents, nurses, technicians and public health professionals) during the COVID-19 pandemic in China and explore factors that are associated with the onset of psychological problems in this population during this public health crisis.

METHODS

A cross-sectional, web-based survey was conducted in February 2020 among healthcare workers during the COVID-19 pandemic. Psychological problems were assessed using the Generalized Anxiety Disorder Scale, Patient Health Questionnaire and Insomnia Severity Index. Logistic regression analyses were used to explore the factors that were associated with psychological problems.

RESULTS

The prevalence of symptoms of anxiety, depression, insomnia and the overall psychological problems in healthcare workers during the COVID-19 pandemic in China was 46.04%, 44.37%, 28.75% and 56.59%, respectively. The prevalence of the overall psychological problems in physicians, medical residents, nurses, technicians and public health professionals was 60.35%, 50.82%, 62.02%, 57.54% and 62.40%, respectively. Compared with healthcare workers who did not participate in front-line work, front-line healthcare workers had a higher risk of anxiety, insomnia and overall psychological problems. In addition, attention to negative or neutral information about the pandemic, receiving negative feedback from families and friends who joined front-line work, and unwillingness to join front-line work if given a free choice were three major factors for these psychological problems.

CONCLUSIONS

Psychological problems are pervasive among healthcare workers during the COVID-19 pandemic. Receiving negative information and participating in front-line work appear to be important risk factors for psychological problems. The psychological health of different healthcare workers should be protected during the COVID-19 pandemic with timely interventions and proper information feedback.

Ambient fine particulate matter is associated with increased emergency ambulance dispatches for psychiatric emergencies

AIMS

As a top ambient pollutant in urban area, fine particulate matter (PM_2.5) has been associated with the occurrence and deterioration of many medical conditions, while limited studies have observed the association with psychiatric conditions. This study aimed to investigate the association between short-term PM_2.5 exposure and psychiatric emergency events, and further explored the variation by age, sex and seasonal patterns, which have been suggested to be associated with both psychiatric risk and pollutant toxicity.

METHODS

We used time-series analysis to investigate the association between short-term exposure of PM_2.5 and emergency ambulance dispatches for psychiatric emergencies (EPE) (n = 158634) in Beijing, one of the top polluted cities in China during the study period between 2008 and 2014. Stratified analyses were conducted to examine the effects of age, sex and seasonal pattern.

RESULTS

Every 10 μg/m³ increase of the PM_2.5 concentration was associated with a 0.12% increase of the same-day overall EPE (95% CI: 0.03-0.22%, p = 0.013) and a 0.12% increase of the suicide-related EPE at lag 2 (95%CI: 0.01-0.24%, p = 0.041). The associations remained when adjusted for sunlight duration. An age effect was observed where children (age <18) showed a higher risk of suicide-related EPE after PM_2.5 exposure compared to adults (18 ≤ age≤64). We did not observe evidence of effect modification by sex and season based on the results of stratified analysis.

CONCLUSIONS

We found a positive association between acute PM_2.5 exposure and increased psychiatric emergency presentations indicated by emergency ambulance dispatches data. Children were more vulnerable and might develop psychiatric problems including those leading to suicide. Public awareness of the health risks of PM_2.5 is important to strengthen current efforts to reduce emissions.

Ambient fine particulate matter is associated with increased emergency ambulance dispatches for psychiatric emergencies

AIMS

As a top ambient pollutant in urban area, fine particulate matter (PM_2.5) has been associated with the occurrence and deterioration of many medical conditions, while limited studies have observed the association with psychiatric conditions. This study aimed to investigate the association between short-term PM_2.5 exposure and psychiatric emergency events, and further explored the variation by age, sex and seasonal patterns, which have been suggested to be associated with both psychiatric risk and pollutant toxicity.

METHODS

We used time-series analysis to investigate the association between short-term exposure of PM_2.5 and emergency ambulance dispatches for psychiatric emergencies (EPE) (n = 158634) in Beijing, one of the top polluted cities in China during the study period between 2008 and 2014. Stratified analyses were conducted to examine the effects of age, sex and seasonal pattern.

RESULTS

Every 10 μg/m³ increase of the PM_2.5 concentration was associated with a 0.12% increase of the same-day overall EPE (95% CI: 0.03-0.22%, p = 0.013) and a 0.12% increase of the suicide-related EPE at lag 2 (95%CI: 0.01-0.24%, p = 0.041). The associations remained when adjusted for sunlight duration. An age effect was observed where children (age <18) showed a higher risk of suicide-related EPE after PM_2.5 exposure compared to adults (18 ≤ age≤64). We did not observe evidence of effect modification by sex and season based on the results of stratified analysis.

CONCLUSIONS

We found a positive association between acute PM_2.5 exposure and increased psychiatric emergency presentations indicated by emergency ambulance dispatches data. Children were more vulnerable and might develop psychiatric problems including those leading to suicide. Public awareness of the health risks of PM_2.5 is important to strengthen current efforts to reduce emissions.

Factors in Sustained Compliance to a Symptom-Reporting Mobile Application: Implications for Clinical Implementation

Background: The Internet-based Computerized Patient Assessment System (iComPAsS), a remote pain- and symptom-reporting application was developed to optimize pain monitoring and management. This subanalysis sought to examine factors influencing compliance, to gauge the sustainability of its effects and to guide further development and implementation as part of usual care. Aim: This analysis sought to examine factors influencing compliance, to gauge the sustainability of its effects and to guide further development and implementation as part of usual care. Methods: Patients ≥ 18 years old, with cancer and moderate-severe pain were randomized to standard pain management with pain diary or iComPAsS. Pain and symptom severity (using Edmonton Symptom Assessment Scale) and compliance (to iComPAsS or diary) were evaluated at week 0, 3, 6, 12 and 20. The Treatment Self-regulation Questionnaire (TSRQ), used to assess patient motivation, was administered at week 0, 6, 12 and 20. Pain levels and compliance were compared between the groups using the Student t-test. The Pearson correlation coefficient was used to examine the relationship between compliance and pain control, perceived competence in pain self-care, and relative autonomy index. Results: Out of 100 patients enrolled, 76 were included in the analysis (control; 37; iComPAsS, 39). Baseline pain levels and TSRQ characteristics were similar between the groups. Initial compliance and pain control at week 3 were significantly higher in the iComPAsS group. For the iCompAsS group, compliance directly correlated with uncontrolled pain and intrinsic motivation, and was more sustained compared with the control group. Conclusion: The iComPAsS elicited rapid uptake and sustained compliance through intrinsic motivation. When adopting the iComPAsS for clinical use, patient baseline motivation levels may be assessed using the TSRQ, and depressive symptoms and other barriers to engagement must be identified.

Orexin A Differentially Influences the Extinction Retention of Recent and Remote Fear Memory

Recently the role of the orexin system in the learning and memory, especially orexin A, which could enhance fear memory through regulating the activity of amygdala, has drawn considerable attention. However, the relationship between orexin A and extinction memory remains unclear. To investigate the effect of orexin A on extinction memory in humans, we recruited 43 male subjects and divided them into a recent group and remote group. After acquiring Pavlovian fear conditioning, individuals in recent group experienced fear extinction 24 h after acquisition, and remote group underwent extinction 2 weeks later. Meanwhile, plasma orexin A levels before extinction were measured by enzyme-linked immunosorbent assay. Both groups received memory test 24 h after fear extinction. The results showed that both recent and remote groups successfully acquired fear conditioning and had spontaneous recovery at test. In particular, the correlational analysis indicated that orexin A levels before extinction were negatively associated with fear responses during test only in recent group, but not in remote group. Moreover, individuals with high orexin A levels still kept low fear responses after extinction in recent group by subgroup analyses. The results suggest that orexin A could influence the retention of recent fear memory extinction, without affecting remote fear extinction. These findings remind us the orexin system can be a potential treatment target for fear-related disorders, and the mechanisms of recent and remote fear extinction may be different.

Effect of FK506 in reducing scar formation by inducing fibroblast apoptosis after sciatic nerve injury in rats

We previously demonstrated that FK506, a generally applied immunosuppressant in organ transplantation, could promote peripheral nerve regeneration through reducing scar formation. However, little is known about how FK506 reduces scar formation. Herein we investigated the influence of FK506 on fibroblast proliferation and its correlation with scar formation after sciatic nerve injury in rats, and further explored the effect of FK506 on fibroblast proliferation and apoptosis in vitro. Masson staining and immunohistochemistry revealed that scar area and fibroblast number in the nerve anastomosis of sciatic nerve-injured rats were significantly reduced after FK506 administration. The scar area had a significant positive correlation with the fibroblast number, as detected by linear correlation analysis. CCK-8 assay and flow cytometry indicated that FK506 also inhibited proliferation and induced apoptosis of fibroblasts in vitro. It was primarily phosphorylation of JNK and ERK that were activated during the apoptosis of fibroblast. Pretreatment of cells with JNK inhibitor, SP600125, or ERK inhibitor, PD98059, could inhibit FK506-induced fibroblast apoptosis, respectively. Moreover, simultaneous application of both inhibitors had additive roles in cell protection from apoptosis. These results suggest that FK506-induced fibroblast apoptosis contributes to the suppression of fibroblast proliferation and then results in the reduction of scar formation in sciatic nerve-injured rat, and that JNK and ERK are involved in FK506-induced fibroblast apoptosis.

Epithelial stem/progenitor cells in lung postnatal growth, maintenance, and repair

The adult lung consists of a trachea leading into a system of branched airways ending in millions of alveolar sacs. It contains many different epithelial cell types arranged in precise patterns along the proximodistal axis. Each region of the lung has the capacity to repair through the proliferation of different epithelial cell types. However, the precise identity of the cells mediating repair is not fully resolved. To address this problem, we are using genetic lineage-labeling techniques in the mouse. The tools we have made will also be useful for understanding how progenitor cell behavior is regulated under normal and pathological conditions.

Unusual persistence in healthy volunteers and ill patients of hyperimmune immunoglobulin directed against multiple Pseudomonas O-chain and Klebsiella serotypes after intravenous infusion

Persistence of intravenous (i.v.) hyperimmune immunoglobulin (100 mg/kg) directed against clinically predominant serotypes of Pseudomonas and Klebsiella in ill, febrile patients was compared to healthy volunteers to determine if ill patients have a decreased Ig half-life resulting in an increased immunoglobulin requirement. Type-specific antibodies were measured by ELISA for 83 days in eight healthy volunteers and for 35 days in eight ill patients with surgical complications or hematologic malignancy. Mean values and fold rises of antibody concentrations for the two groups were above preinfusion values at 35 days. The antibody fold rises in patients and in healthy volunteers were similar. Type-specific antibody levels in some patients increased after illness coincident with elevation of total immunoglobulins. We conclude that the duration of potentially therapeutic levels of infused type-specific hyperimmune immunoglobulin may persist for a longer period of time than what has been measured for total immunoglobulin. While the mechanism of this persistence remains to be characterized, the possibility of type-specific antibody synthesis induced by immunoglobulin administration must be considered.

Does bowel preparation improve the quality of abdominal gallium scintigraphy?

Physiological accumulation of gallium in the intestine is a major weakness of gallium scintigraphy in evaluating the abdomen. In this study, we used two different cathartics to evaluate the efficacy of bowel cleansing in improving the quality of abdominal gallium imaging. One hundred and fifty patients underwent gallium scintigraphy and were randomly divided into three groups. Group A received no bowel preparation, Group B received 30 ml of castor oil the night before imaging, and Group C received bisacodyl the night before imaging. Gallium activity in the intestine was rated on a three-point scale from 0 to II based on the anterior view of a delayed 48-h gallium image. Our data showed that the incidence of gallium accumulation in the small intestine was low. On the contrary, there was high prevalence of gallium activity in the colon. Forty-eight percent of Group A patients had obvious gallium activity in the colon. The percentage decreased significantly to 28% and 22% in Groups B and C, respectively. No significant difference was noted between Group B and Group C. In conclusion, our data suggest that the application of either castor oil or bisacodyl significantly improves the quality of 48-h abdominal gallium scintigraphy. There were no significant differences in the efficacy of bowel cleansing on gallium activity between these two laxatives.

Modulation of excitatory synaptic transmission by low concentrations of glutamate in cultured rat hippocampal neurons

1. The effects of low micromolar concentrations of glutamate on fast excitatory synaptic responses were studied in microcultures of postnatal rat hippocampal neurons using whole-cell patch clamp recordings. 2. Glutamate depressed the alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor component of excitatory autaptic currents (EACs) with an EC50 of 3.8 microM. 3. Both pre- and postsynaptic effects contributed to the depression of AMPA receptor-mediated EACs. Cyclothiazide and wheatgerm agglutinin, agents which inhibit AMPA receptor desensitization, partially reversed the depression produced by glutamate, as did pertussis toxin, an agent that blocks presynaptic inhibition mediated by metabotropic glutamate receptors. 4. In neurons in which both the AMPA and N-methyl-D-aspartate (NMDA) receptor components of EACs were examined, low concentrations of glutamate depressed the NMDA component of EACs to a greater extent. The EC50 for inhibiting the NMDA component was 1.3 microM. 5. Calcium-dependent desensitization of postsynaptic NMDA receptors contributed to the depression of NMDA receptor-mediated synaptic responses. Both depolarization of postsynaptic neurons to +70 mV to decrease Ca2+ influx via NMDA channels and inclusion of high concentrations of a calcium chelator in recording pipettes decreased the depression of NMDA receptor-mediated EACs. 6. Threo-3-hydroxy-aspartate (THA), an inhibitor of glutamate transport, depressed EACs by about 10% and increased the degree of depression produced by 2.5 microM glutamate, suggesting that glutamate transport in microcultures helps to control ambient glutamate levels. 7. Because the normal extracellular concentration of glutamate is about 1 microM, these results suggest that the ambient glutamate level is an important determinant of synaptic efficacy. Relatively small changes in extracellular glutamate can alter fast excitatory synaptic transmission by both presynaptic and postsynaptic mechanisms.

Passive and synaptic properties of hippocampal neurons grown in microcultures and in mass cultures

1. We used whole cell recordings to compare passive membrane properties and synaptic properties of postnatal rat hippocampal neurons grown for 7-15 days in either conventional mass cultures or on physically restricted microisland cultures. Despite matching microisland and mass culture cell across several variables, there were significant differences between neurons in the two groups regarding passive membrane characteristics and synaptic properties. 2. Microisland neurons displayed significantly faster charging of the membrane capacitance than mass culture counterparts matched with microisland neurons for age, somal diameter, and transmitter phenotype. When we used a two-compartment equivalent circuit model to quantify this result, microisland neurons displayed approximately half the distal capacitance of mass culture neurons. These data suggest that microisland neurons elaborate less extensive neuritic arborizations than mass culture neurons. 3. Evoked synaptic responses were enhanced on microislands compared with mass cultures. Excitatory and inhibitory autaptic currents were more frequent and displayed larger amplitudes on single-neuron microislands than in matched mass culture neurons. 4. In recordings from pairs of neurons in the two environments, we observed a significantly higher probability of obtaining a monosynaptic response on two-neuron microislands than in matched mass culture pairs (85% vs. 42%). Evoked excitatory postsynaptic currents were also significantly larger in the microisland environment, with evoked excitatory synaptic currents from two-neuron microislands exhibiting a mean amplitude 20-fold larger than mass culture monosynaptic responses. 5. The differences in evoked synaptic responses were not reflected in differences in the amplitude or frequency of spontaneous miniature excitatory postsynaptic currents (mEPSCs). Analysis of mEPSC rise times, decay times, and peak amplitudes within individual cells suggests that electrotonic filtering is not an important contributor to the variability of peak amplitudes and decay times of synaptic currents in cells of either culture environment. However, composite data across neurons in both cultures reveal a significant correlation between mEPSC rise and decay times. 6. Out results suggest that the microisland preparation may be a useful tool for exploring factors that influence synapse formation and development. Additionally, the preparation is a particularly convenient model for the study of single-neuron-mediated synaptic events.

Safety and immunogenicity of a polyvalent Escherichia coli vaccine in human volunteers

Since a limited number of O serogroups account for nearly 70% of bacteremic and meningitic Escherichia coli isolates, a polyvalent vaccine was made by conjugating a Pseudomonas aeruginosa exotoxin A carrier protein to the O polysaccharide of 12 serogroups of E. coli (O1, O2, O4, O6-O8, O12, O15, O16, O18, O25, O75). No serious reactions occurred in 88 vaccinees. Four-fold or greater increases in ELISA antibody levels over baseline were greatest (> 60% of vaccinees) for O1, O2, O6-O8 and O15; intermediate (approximately 50%) for O18 and O75, and poorest (> or = 45%) for O4, O12, O16, and O25. Responses with functionally active opsonophagocytic antibody generally paralleled ELISA antibody responses. With the availability of a safe, immunogenic E. coli vaccine, active and passive immunization strategies merit further development as adjunctive treatment for E. coli bacteremia and neonatal meningitis.

Barbiturate depression of a K+ dependent inhibitory synapse is independent of dendritic cable filtering

Technical limitations with intracellular electrophysiological methods usually restrict recording of postsynaptic potentials only from neuronal soma, a site remote from the actual synapse. The intervening dendritic cable interposed between the actual synapse and the site of recording can significantly filter the synaptic signal. Therefore, investigations of drug effect on synaptic mechanisms, based on postsynaptic recordings obtained at the soma, must be interpreted with care. The potential role of dendritic cable filtering in the atypical pentobarbital depression of a K(+)-dependent inhibitory synapse between the P to Nut cell in the posterior packet of the leech was investigated. The effective electrical geometry under the conditions of control and 0.5 mM PNB sufficient to completely abolish the postsynaptic potential were determined from analyses of the membrane charging curves assuming the lumped-soma-short-cable model. Under the control condition, the postsynaptic Nut cell exhibits dendritic dominance with rho = 2.52, normalized equivalent cable length L = 1.08, and a membrane time constant tau o = 52 ms. With phenobarbital application, changes in the geometrical parameters consistent with a decrease in the specific membrane resistance Rm are observed. Simulation of the drug induced change in the electrical geometry demonstrates that the decrease in the post synaptic potential is largely due to the decrease in the soma input resistance and an increase in the cable filter contributes little to the observed depression of the postsynaptic potential. However, the combined effect of the decrease in the input resistance and the increase in the cable filtering of synaptic current is insufficient in explaining the observed total block of the synaptic potential by PNB.(ABSTRACT TRUNCATED AT 250 WORDS)