How ambient temperature affects mood: an ecological momentary assessment study in Switzerland

BACKGROUND

Recent research has suggested that an increase in temperature can negatively affect mental health and increase hospitalization for mental illness. It is not clear, however, what factors or mechanisms mediate this association. We aimed to (1) investigate the associations between ambient temperatures and bad daily mood, and (2) identify variables affecting the strength of these associations (modifiers) including the time, the day of the week and the year of the mood rating, socio-demographic characteristics, sleep quality, psychiatric disorders and the personality trait neuroticism in the community.

METHODS

Data stemmed from the second follow-up evaluation of CoLaus|PsyCoLaus, a prospective cohort study conducted in the general population of Lausanne (Switzerland). The 906 participants rated their mood level four times a day during seven days using a cell phone app. Mixed-effects logistic regression was used to determine the association between daily maximum temperature and mood level. Participant ID was inserted as a random effect in the model, whereas the time of the day, the day of the week and the year were inserted as fixed effects. Models were controlled for several confounders (socio-demographic characteristics, sleep quality, weather parameters and air pollutants). Stratified analyses were conducted based on socio-demographic characteristics, sleep quality, presence of psychiatric disorders or a high neuroticism.

RESULTS

Overall, the probability of having a bad mood for the entire day decreased by 7.0% (OR: 0.93: 95% CI 0.88, 0.99) for each 5 °C increase in maximum temperature. A smaller and less precise effect (-3%; OR: 0.97: 95% CI 0.91, 1.03) was found when controlling for sunshine duration. A higher association was found in participants with bipolar disorder (-23%; OR: 0.77: 95% CI 0.51, 1.17) and in participants with a high neuroticism (-13%; OR: 0.87 95% CI 0.80, 0.95), whereas the association was reversed for participants with anxiety (20%; OR: 1.20: 95% CI 0.90, 1.59), depression (18%; OR: 1.18 95% CI 0.94, 1.48) and schizophrenia (193%; OR: 2.93 95% CI 1.17, 7.73).

CONCLUSIONS

According to our findings, rising temperatures may positively affect mood in the general population. However, individuals with certain psychiatric disorders, such as anxiety, depression, and schizophrenia, may exhibit altered responses to heat, which may explain their increased morbidity when exposed to high temperatures. This suggests that tailored public health policies are required to protect this vulnerable population.

Gene-diet interactions and cardiovascular diseases: a systematic review of observational and clinical trials

BACKGROUND

Both genetic background and diet are important determinants of cardiovascular diseases (CVD). Understanding gene-diet interactions could help improve CVD prevention and prognosis. We aimed to summarise the evidence on gene-diet interactions and CVD outcomes systematically.

METHODS

We searched MEDLINE^® via Ovid, Embase, PubMed^®, and The Cochrane Library for relevant studies published until June 6th 2022. We considered for inclusion cross-sectional, case-control, prospective cohort, nested case-control, and case-cohort studies as well as randomised controlled trials that evaluated the interaction between genetic variants and/or genetic risk scores and food or diet intake on the risk of related outcomes, including myocardial infarction, coronary heart disease (CHD), stroke and CVD as a composite outcome. The PROSPERO protocol registration code is CRD42019147031.

RESULTS AND DISCUSSION

We included 59 articles based on data from 29 studies; six articles involved multiple studies, and seven did not report details of their source population. The median sample size of the articles was 2562 participants. Of the 59 articles, 21 (35.6%) were qualified as high quality, while the rest were intermediate or poor. Eleven (18.6%) articles adjusted for multiple comparisons, four (7.0%) attempted to replicate the findings, 18 (30.5%) were based on Han-Chinese ethnicity, and 29 (49.2%) did not present Minor Allele Frequency. Fifty different dietary exposures and 52 different genetic factors were investigated, with alcohol intake and ADH1C variants being the most examined. Of 266 investigated diet-gene interaction tests, 50 (18.8%) were statistically significant, including CETP-TaqIB and ADH1C variants, which interacted with alcohol intake on CHD risk. However, interactions effects were significant only in some articles and did not agree on the direction of effects. Moreover, most of the studies that reported significant interactions lacked replication. Overall, the evidence on gene-diet interactions on CVD is limited, and lack correction for multiple testing, replication and sample size consideration.

Nationwide Analysis of the Heat- and Cold-Related Mortality Trends in Switzerland between 1969 and 2017: The Role of Population Aging

BACKGROUND

Because older adults are particularly vulnerable to nonoptimal temperatures, it is expected that the progressive population aging will amplify the health burden attributable to heat and cold due to climate change in future decades. However, limited evidence exists on the contribution of population aging on historical temperature-mortality trends.

OBJECTIVES

We aimed to a) assess trends in heat- and cold-related mortality in Switzerland between 1969 and 2017 and b) to quantify the contribution of population aging to the observed patterns.

METHODS

We collected daily time series of all-cause mortality by age group (<65, 65-79, and 80 y and older) and mean temperature for each Swiss municipality (1969-2017). We performed a two-stage time-series analysis with distributed lag nonlinear models and multivariate longitudinal meta-regression to obtain temperature-mortality associations by canton, decade, and age group. We then calculated the corresponding excess mortality attributable to nonoptimal temperatures and compared it to the estimates obtained in a hypothetical scenario of no population aging.

RESULTS

Between 1969 and 2017, heat- and cold-related mortality represented 0.28% [95% confidence interval (CI): 0.18, 0.37] and 8.91% (95% CI: 7.46, 10.21) of total mortality, which corresponded to 2.4 and 77 deaths per 100,000 people annually, respectively. Although mortality rates for heat slightly increased over time, annual number of deaths substantially raised up from 74 (12;125) to 181 (39;307) between 1969-78 and 2009-17, mostly driven by the ≥80-y-old age group. Cold-related mortality rates decreased across all ages, but annual cold-related deaths still increased among the ≥80, due to the increase in the population at risk. We estimated that heat- and cold-related deaths would have been 52.7% and 44.6% lower, respectively, in the most recent decade in the absence of population aging.

DISCUSSION

Our findings suggest that a substantial proportion of historical temperature-related impacts can be attributed to population aging. We found that population aging has attenuated the decrease in cold-related mortality and amplified heat-related mortality. https://doi.org/10.1289/EHP9835.

Suicides and ambient temperature in Switzerland: A nationwide time-series analysis

AIM OF THE STUDY

Previous literature suggests that ambient temperature may play a role in increasing the risk of suicide. Although in Switzerland suicides are an important cause of death, limited research exists on risk factors for suicidal behaviour, including ambient temperature. We aimed to assess the short-term association between ambient temperature and suicide risk in Switzerland between 1995 and 2016, and the differences by region, individual characteristics and method of suicide.

METHODS

We collected daily data on suicides and mean temperatures in each canton of Switzerland. We used a two-stage approach, consisting of a case time series analysis using conditional quasi-Poisson and distributed lag non-linear models followed by a multivariate meta-regression analysis. We conducted subgroup analyses by sex, age (<35, 35-65 and >65 years) and method of suicide (violent or nonviolent).

RESULTS

Between 1995 and 2016, there were a total of 24,067 suicides in Switzerland. Overall, we found a positive and non-linear temperature-suicide association in all regions. On average, the risk of suicide increased by 34% (1.34 relative risk [95% confidence interval: 1.19-1.52]) from the 10th to the 99th temperature percentile in Switzerland (lag period of 0-2 days). Indications of larger risks were mostly found in females, younger individuals (<35 years) and with nonviolent methods. Regional risks ranged from 24% (East region) to 55% (North-West region).

CONCLUSIONS

Our findings suggest that increasing temperatures could be considered a risk factor for suicidal behaviour in Switzerland. Knowledge of the profile of people committing suicide could help us to understand the mechanisms behind this association and thus support policymakers in suicide prevention.

Ambient temperature and mental health hospitalizations in Bern, Switzerland: A 45-year time-series study

BACKGROUND

Psychiatric disorders constitute a major public health concern that are associated with substantial health and socioeconomic burden. Psychiatric patients may be more vulnerable to high temperatures, which under current climate change projections will most likely increase the burden of this public health concern.

OBJECTIVE

This study investigated the short-term association between ambient temperature and mental health hospitalizations in Bern, Switzerland.

METHODS

Daily hospitalizations for mental disorders between 1973 and 2017 were collected from the University Hospital of Psychiatry and Psychotherapy in Bern. Population-weighted daily mean ambient temperatures were derived for the catchment area of the hospital from 2.3-km gridded weather maps. Conditional quasi-Poisson regression with distributed lag linear models were applied to assess the association up to three days after the exposure. Stratified analyses were conducted by age, sex, and subdiagnosis, and by subperiods (1973-1989 and 1990-2017). Additional subanalyses were performed to assess whether larger risks were found during the warm season or were due to heatwaves.

RESULTS

The study included a total number of 88,996 hospitalizations. Overall, the hospitalization risk increased linearly by 4.0% (95% CI 2.0%, 7.0%) for every 10°C increase in mean daily temperature. No evidence of a nonlinear association or larger risks during the warm season or heatwaves was found. Similar estimates were found across for all sex and age categories, and larger risks were found for hospitalizations related to developmental disorders (29.0%; 95% CI 9.0%, 54.0%), schizophrenia (10.0%; 95% CI 4.0%, 15.0%), and for the later rather than the earlier period (5.0%; 95% CI 2.0%, 8.0% vs. 2.0%; 95% CI -3.0%, 8.0%).

CONCLUSIONS

Our findings suggest that increasing temperatures could negatively affect mental status in psychiatric patients. Specific public health policies are urgently needed to protect this vulnerable population from the effects of climate change.

Impact of ambient temperature on mental health in Bern, Switzerland: a time-series study

Background

Previous studies suggest that people with mental disorders are more vulnerable to increased ambient temperatures (AT). In Switzerland, neuropsychiatric diseases contribute up to 35.1% of the total burden of disease. This burden could possibly increase in the future under current climate change scenarios, if no appropriate public health measures were implemented. However, there is lack of evidence on the impact of AT on mental health in Switzerland.

Objective

This study aimed to investigate the short-term association between AT and mental health hospitalizations in Bern, Switzerland.

Methods

From 1973 to 2010, we collected individual data on daily hospitalizations for mental disorders (71,931) from the University Hospital of Psychiatry and Psychotherapy in Bern. We used population-weighted daily mean AT for the canton of Bern derived from the 2.2-km gridded weather data provided by MeteoSwiss. We applied conditional Poisson regression with distributed lag linear models to assess the association and to account for delayed effects up to 3 days after the exposure. We conducted stratified analysis and by age, sex and diagnosis.

Results

The overall risk of hospitalizations increased linearly by 3.0% (95% CI: 0.0%, 6.0%) for every 10C°C-increase in mean daily AT. No differences in risk estimates were found across sex (3.0% in males (95% CI: 0%, 7.0%) and 4.0% in females (95% CI: 0%, 8.0%)) and age groups (≥ 45 years old: 4.0% (95% CI: 0%, 9.0%) and &lt;45 years old: 3.0% (95% CI 0%, 7%)). Larger association estimates were found for schizophrenia (10.0%; 95% CI 4%, 16%), while no association was found for substance abuse (0.0%; 95% CI -7.0%, 6.0%).

Conclusions

Our preliminary findings suggest that increasing AT are associated with an increased risk in hospitalizations due to mental disorders in Bern. Specific public health policies should be urgently implemented in order to protect this vulnerable population sub-group from the challenges of climate change.

Key messages

Increased ambient temperatures are associated with an increased risk in hospitalizations due to mental health disorders. Specific health policies should be implement to protect mental health patients from the challenges of climate change.

Effectiveness, benefit harm and cost effectiveness of colorectal cancer screening in Austria

BACKGROUND

Clear evidence on the benefit-harm balance and cost effectiveness of population-based screening for colorectal cancer (CRC) is missing. We aim to systematically evaluate the long-term effectiveness, harms and cost effectiveness of different organized CRC screening strategies in Austria.

METHODS

A decision-analytic cohort simulation model for colorectal adenoma and cancer with a lifelong time horizon was developed, calibrated to the Austrian epidemiological setting and validated against observed data. We compared four strategies: 1) No Screening, 2) FIT: annual immunochemical fecal occult blood test age 40-75 years, 3) gFOBT: annual guaiac-based fecal occult blood test age 40-75 years, and 4) COL: 10-yearly colonoscopy age 50-70 years. Predicted outcomes included: benefits expressed as life-years gained [LYG], CRC-related deaths avoided and CRC cases avoided; harms as additional complications due to colonoscopy (physical harm) and positive test results (psychological harm); and lifetime costs. Tradeoffs were expressed as incremental harm-benefit ratios (IHBR, incremental positive test results per LYG) and incremental cost-effectiveness ratios [ICER]. The perspective of the Austrian public health care system was adopted. Comprehensive sensitivity analyses were performed to assess uncertainty.

RESULTS

The most effective strategies were FIT and COL. gFOBT was less effective and more costly than FIT. Moving from COL to FIT results in an incremental unintended psychological harm of 16 additional positive test results to gain one life-year. COL was cost saving compared to No Screening. Moving from COL to FIT has an ICER of 15,000 EUR per LYG.

CONCLUSIONS

Organized CRC-screening with annual FIT or 10-yearly colonoscopy is most effective. The choice between these two options depends on the individual preferences and benefit-harm tradeoffs of screening candidates.

Guidance for a causal comparative effectiveness analysis emulating a target trial based on big real world evidence: when to start statin treatment

Aim: The aim of this project is to describe a causal (counterfactual) approach for analyzing when to start statin treatment to prevent cardiovascular disease using real-world evidence. Methods: We use directed acyclic graphs to operationalize and visualize the causal research question considering selection bias, potential time-independent and time-dependent confounding. We provide a study protocol following the 'target trial' approach and describe the data structure needed for the causal assessment. Conclusion: The study protocol can be applied to real-world data, in general. However, the structure and quality of the database play an essential role for the validity of the results, and database-specific potential for bias needs to be explicitly considered.

Budget Impact Analysis of Cancer Screening: A Methodological Review

BACKGROUND

Budget impact analyses (BIAs) describe changes in intervention- and disease-related costs of new technologies. Evidence on the quality of BIAs for cancer screening is lacking.

OBJECTIVES

We systematically reviewed the literature and methods to assess how closely BIA guidelines are followed when BIAs are performed for cancer-screening programs.

DATA SOURCES

Systematic searches were conducted in MEDLINE, EMBASE, EconLit, CRD (Centre for Reviews and Dissemination, University of York), and CEA registry of the Tufts Medical Center.

STUDY ELIGIBILITY CRITERIA

Eligible studies were BIAs evaluating cancer-screening programs published in English, 2010-2018.

SYNTHESIS METHODS

Standardized evidence tables were generated to extract and compare study characteristics outlined by the ISPOR BIA Task Force.

RESULTS

Nineteen studies were identified evaluating screening for breast (5), colorectal (6), cervical (3), lung (1), prostate (3), and skin (1) cancers. Model designs included decision-analytic models (13) and simple cost calculators (6). From all studies, only 53% reported costs for a minimum of 3 years, 58% compared to a mix of screening options, 42% reported model validation, and 37% reported uncertainty analysis for participation rates. The quality of studies appeared to be independent of cancer site.

LIMITATIONS

"Gray" literature was not searched, misinterpretation is possible due to limited information in publications, and focus was on international methodological guidelines rather than regional guidelines.

CONCLUSIONS

Our review highlights considerable variability in the extent to which BIAs evaluating cancer-screening programs followed recommended guidelines. The annual budget impact at least over the next 3-5 years should be estimated. Validation and uncertainty analysis should always be conducted. Continued dissemination efforts of existing best-practice guidelines are necessary to ensure high-quality analyses.

Alternative Conversion Methods for Transition Probabilities in State-Transition Models: Validity and Impact on Comparative Effectiveness and Cost-Effectiveness

Background. In state-transition models (STMs), decision problems are conceptualized using health states and transitions among those health states after predefined time cycles. The naive, commonly applied method (C) for cycle length conversion transforms all transition probabilities separately. In STMs with more than 2 health states, this method is not accurate. Therefore, we aim to describe and compare the performance of method C with that of alternative matrix transformation methods. Design. We compare 2 alternative matrix transformation methods (Eigenvalue method [E], Schure-Padé method [SP]) to method C applied in an STM of 3 different treatment strategies for women with breast cancer. We convert the given annual transition matrix into a monthly-cycle matrix and evaluate induced transformation errors for the transition matrices and the long-term outcomes: life years, quality-adjusted life-years, costs and incremental cost-effectiveness ratios, and the performance related to the decisions. In addition, we applied these transformation methods to randomly generated annual transition matrices with 4, 7, 10, and 20 health states. Results. In theory, there is no generally applicable correct transformation method. Based on our simulations, SP resulted in the smallest transformation-induced discrepancies for generated annual transition matrices for 2 treatment strategies. E showed slightly smaller discrepancies than SP in the strategy, where one of the direct transitions between health states was excluded. For long-term outcomes, the largest discrepancy occurred for estimated costs applying method C. For higher dimensional models, E performs best. Conclusions. In our modeling examples, matrix transformations (E, SP) perform better than transforming all transition probabilities separately (C). Transition probabilities based on alternative conversion methods should therefore be applied in sensitivity analyses.

Personalized treatment of women with early breast cancer: a risk-group specific cost-effectiveness analysis of adjuvant chemotherapy accounting for companion prognostic tests OncotypeDX and Adjuvant!Online

BACKGROUND

Due to high survival rates and the relatively small benefit of adjuvant therapy, the application of personalized medicine (PM) through risk stratification is particularly beneficial in early breast cancer (BC) to avoid unnecessary harms from treatment. The new 21-gene assay (OncotypeDX, ODX) is a promising prognostic score for risk stratification that can be applied in conjunction with Adjuvant!Online (AO) to guide personalized chemotherapy decisions for early BC patients. Our goal was to evaluate risk-group specific cost effectiveness of adjuvant chemotherapy for women with early stage BC in Austria based on AO and ODX risk stratification.

METHODS

A previously validated discrete event simulation model was applied to a hypothetical cohort of 50-year-old women over a lifetime horizon. We simulated twelve risk groups derived from the joint application of ODX and AO and included respective additional costs. The primary outcomes of interest were life-years gained, quality-adjusted life-years (QALYs), costs and incremental cost-effectiveness (ICER). The robustness of results and decisions derived were tested in sensitivity analyses. A cross-country comparison of results was performed.

RESULTS

Chemotherapy is dominated (i.e., less effective and more costly) for patients with 1) low ODX risk independent of AO classification; and 2) low AO risk and intermediate ODX risk. For patients with an intermediate or high AO risk and an intermediate or high ODX risk, the ICER is below 15,000 EUR/QALY (potentially cost effective depending on the willingness-to-pay). Applying the AO risk classification alone would miss risk groups where chemotherapy is dominated and thus should not be considered. These results are sensitive to changes in the probabilities of distant recurrence but not to changes in the costs of chemotherapy or the ODX test.

CONCLUSIONS

Based on our modeling study, chemotherapy is effective and cost effective for Austrian patients with an intermediate or high AO risk and an intermediate or high ODX risk. In other words, low ODX risk suggests chemotherapy should not be considered but low AO risk may benefit from chemotherapy if ODX risk is high. Our analysis suggests that risk-group specific cost-effectiveness analysis, which includes companion prognostic tests are essential in PM.

Polyunsaturated fatty acid deficiency during neurodevelopment in mice models the prodromal state of schizophrenia through epigenetic changes in nuclear receptor genes

The risk of schizophrenia is increased in offspring whose mothers experience malnutrition during pregnancy. Polyunsaturated fatty acids (PUFAs) are dietary components that are crucial for the structural and functional integrity of neural cells, and PUFA deficiency has been shown to be a risk factor for schizophrenia. Here, we show that gestational and early postnatal dietary deprivation of two PUFAs-arachidonic acid (AA) and docosahexaenoic acid (DHA)-elicited schizophrenia-like phenotypes in mouse offspring at adulthood. In the PUFA-deprived mouse group, we observed lower motivation and higher sensitivity to a hallucinogenic drug resembling the prodromal symptoms in schizophrenia. Furthermore, a working-memory task-evoked hyper-neuronal activity in the medial prefrontal cortex was also observed, along with the downregulation of genes in the prefrontal cortex involved in oligodendrocyte integrity and the gamma-aminobutyric acid (GABA)-ergic system. Regulation of these genes was mediated by the nuclear receptor genes Rxr and Ppar, whose promoters were hyper-methylated by the deprivation of dietary AA and DHA. In addition, the RXR agonist bexarotene upregulated oligodendrocyte- and GABA-related gene expression and suppressed the sensitivity of mice to the hallucinogenic drug. Notably, the expression of these nuclear receptor genes were also downregulated in hair-follicle cells from schizophrenia patients. These results suggest that PUFA deficiency during the early neurodevelopmental period in mice could model the prodromal state of schizophrenia through changes in the epigenetic regulation of nuclear receptor genes.

3D CT Angiography as a Pre-Embolization Study for Embolization of Cerebral Aneurysms

An image guide for aneurysm embolization based on three dimensional CT angiography is reported. Multiplanner reformation (MPR) can measure the neck and dome of the aneurysm accurately enough to select the first coils for aneurysms.

For neck evaluation, cut model and virtual endoscope are helpful because we can observe the neck from inside of dome or parent artery. Proximal arteries are visualized by 3D images and MPR if needed.

Using laser lithography, we can get a real model of aneurysm and parent artery through which we can insert microcatheters and coils. 3D CTA is a dependable modality for embolization of cerebral aneurysms.

Aberrant DNA methylation associated with bipolar disorder identified from discordant monozygotic twins

To search DNA methylation difference between monozygotic twins discordant for bipolar disorder, we applied a comprehensive genome scan method, methylation-sensitive representational difference analysis (MS-RDA) to lymphoblastoid cells derived from the twins. MS-RDA isolated 10 DNA fragments derived from 5' region of known genes/ESTs. Among these 10 regions, four regions showed DNA methylation differences between bipolar twin and control co-twin confirmed by bisulfite sequencing. We performed a case-control study of DNA methylation status of these four regions by pyrosequencing. Two regions, upstream regions of spermine synthase (SMS) and peptidylprolyl isomerase E-like (PPIEL) (CN265253), showed aberrant DNA methylation status in bipolar disorder. SMS, a gene on X chromosome, showed significantly higher DNA methylation level in female patients with bipolar disorder compared with control females. However, there was no difference of mRNA expression. In PPIEL, DNA methylation level was significantly lower in patients with bipolar II disorder than in controls. The expression level of PPIEL was significantly higher in bipolar II disorder than in controls. We found strong inverse correlation between gene expression and DNA methylation levels of PPIEL. These results suggest that altered DNA methylation statuses of PPIEL might have some significance in pathophysiology of bipolar disorder..

Molecular characterization of bipolar disorder by comparing gene expression profiles of postmortem brains of major mental disorders

We performed the oligonucleotide microarray analysis in bipolar disorder, major depression, schizophrenia, and control subjects using postmortem prefrontal cortices provided by the Stanley Foundation Brain Collection. By comparing the gene expression profiles of similar but distinctive mental disorders, we explored the uniqueness of bipolar disorder and its similarity to other mental disorders at the molecular level. Notably, most of the altered gene expressions in each disease were not shared by one another, suggesting the molecular distinctiveness of these mental disorders. We found a tendency of downregulation of the genes encoding receptor, channels or transporters, and upregulation of the genes encoding stress response proteins or molecular chaperons in bipolar disorder. Altered expressions in bipolar disorder shared by other mental disorders mainly consisted of upregulation of the genes encoding proteins for transcription or translation. The genes identified in this study would be useful for the understanding of the pathophysiology of bipolar disorder, as well as the common pathophysiological background in major mental disorders at the molecular level. In addition, we found the altered expression of LIM and HSPF1 both in the brains and lymphoblastoid cells in bipolar disorder. These genes may have pathophysiological importance and would be novel candidate genes for bipolar disorder.

High- and moderately high-methionine uptake demonstrated by PET in a patient with a subacute cerebral infarction

In patients with cerebral tumors, high accumulations of L-methyl-11C-methionine (11C-Met) have been reported in some cases of cerebral ischemic disease, but no high accumulations of 11C-Met in areas where only transient arterial occlusions are most likely to occur have been reported. Herein we present a case of a high accumulation of 11C-Met in an area of frontal interhemispheric cerebral infarction and a moderately high accumulation with an unclear margin in a distant frontal convexity area. A craniotomy revealed a subacute stage of cerebral infarction in the interhemispheric lesion, and an ischemic change in the distant convexity area. Sixteen months after onset, CT scans demonstrated an infarction area in the interhemispheric lesion only, and no atrophic changes were observed in the distant convexity area indicating that no serious tissue damage had occurred.

Protein binding of a DRPLA family through arginine-glutamic acid dipeptide repeats is enhanced by extended polyglutamine

Dentatorubral-pallidoluysian atrophy (DRPLA) is one of the hereditary neurodegenerative disorders caused by expansion of CAG/glutamine repeats. To investigate the normal function of the DRPLA gene and the pathogenic mechanism of neuron death in specific areas of the brain, we isolated and analyzed a gene that shares a notable motif with DRPLA, arginine-glutamic acid (RE) dipeptide repeats. The gene isolated, designated RERE, has an open reading frame of 1566 amino acids, of which the C-terminal portion has 67% homology to DRPLA, whereas the N-terminal portion is distinctive. RERE also contains arginine-aspartic acid (RD) dipeptide repeats and putative nuclear localization signal sequences, but no polyglutamine tracts. RERE is expressed at a low level in most tissues examined. Immunoprecipitation and in vitro binding assays demonstrate that the DRPLA and RERE proteins bind each other, for which one of the RE repeats has a primary role, and extended polyglutamine enhances the binding. With engineered constructs fused with a tag, the RERE protein localized predominantly in the nucleus. Moreover, when RERE is overexpressed, the distribution of endogenous DRPLA protein alters from the diffused to the speckled pattern in the nucleus so as to co-localize with RERE. More RERE protein is recruited into nuclear aggregates of the DRPLA protein with extended polyglutamine than into those of pure polyglutamine. These results reveal a function for the DRPLA protein in the nucleus and the RE repeat in the protein-protein interaction.

Embolism in the Superior Cerebellar Artery following Coil Embolization of Basilar Tip Aneurysms: Anatomy and Hemodynamics

We aimed to identify anatomic factors favoring intra-aneurysmal clot embolization complicating coil embolization of basilar tip aneurysms.

Thirty basilar tip aneurysm cases were classified angiographically into three types according to branching pattern of the superior cerebellar artery (SCA) and coil embolization complications were analyzed. The SCA may arise from the basilar artery (BA) just proximal to the origin of the posterior cerebral artery (PCA), initially coursing at an angle (more than 60°) relative to the BA, (type A). Alternatively the SCA may originate directly from the PCA at a sharp angle less than 30° relative to the BA (type C). Type B includes patterns intermediate between types A and C. Behavior of particles chosen to simulate intra-aneurysmal clots was also observed in a plastic tube model with pulsatile water flow simulating configurations A and C.

Type C branching was seen in 35% (21/60) of SCA, being dominant on the left side and associated with large aneurysms and broad necks. All 3 of 24 coil embolization patients with ischemic complications in the SCA territory had large aneurysms and type C SCA branching, 2 aneurysms having broad necks. In the plastic model embolized “clots” more frequently lodged in type C than in type A SCA. “Clots” close to the orifice migrated more easily than those in the dome of the plastic aneurysm.

Large basilar tip aneurysms with broad necks carry a risk of intra-aneurysmal clot migration into the SCA, during and after the embolization, especially in type C configurations, because pulsatile blood flow in the basilar artery may disperse clots between the coils and carry them into the sharply angulated SCA. Avoiding this complication requires meticulous coil packing to interrupt inflow into the aneurysm as well as appropriate anti-coagulation therapy.

Neural activation of the brain with hemodynamic insufficiency

Little is known about how ischemia affects hemodynamic responses to neural activation in the brain. We compare the effects of a motor activation task and a cerebral vasodilating agent, acetazolamide (ACZ), on regional cerebral blood flow (rCBF) in primary sensorimotor cortex (PSM) in six patients with major cerebral artery steno-occlusive lesions without paresis of the upper extremities. Quantitative rCBF was measured in all patients using H2(15)O autoradiographic method and positron emission tomography. The CBF was determined at rest, during a bimanual motor activation task, and 10 minutes after ACZ administration. With bimanual motor activation, rCBF increased significantly in both PSM compared with at rest (P < 0.01 on lesion side, and P < 0.02 on contralateral side). However, rCBF did not increase after ACZ injection in the PSM on the lesion side, whereas rCBF increased significantly in the contralateral PSM after ACZ injection compared with the level at rest. This result suggests that despite a decreased hemodynamic reserve, there is a nearly normal flow response to neural activation, indicating that the mechanism of vasodilation responsible for perfusion change is different for acetazolamide and neural activation. The relations among neural activation, hemodynamic status, and cerebral metabolism in the ischemic stroke patients are discussed.

Determining the Optimal Fluoroscopic View during Aneurysmal Embolization with Rotation DSA

To prevent coil protrusion into the parent artery, the fluoroscopic view during coil packing is quite important. However it is not always easy to find out the optimal fluoroscopic view.

We applied a rotation DSA to predict the optimal fluoroscopic view for the endovascular treatment of 4 cases with a cerebral aneurysm.

Since the trajectory of the C-arm is restricted within 60 degrees only around the patient's head and the number of DSA shots are limited rather than conventional DSA, we employed three dimensional CT angiography (3D-CT angiography) to focus the range of C-arm rotation.

Rotation DSA proved quite useful to determine the optimal fluoroscopic view, when combined with pre-estimation by 3D-CT angiography.

Dentatorubral and pallidoluysian atrophy expansion of an unstable CAG trinucleotide on chromosome 12p

Dentatorubral and pallidoluysian atrophy (DRPLA) is an autosomal dominant neurodegenerative disorder characterized by combined systemic degeneration of the dentatofugal and pallidofugal pathways. We investigated a candidate gene and found that DRPLA patients had an expanded CAG trinucleotide repeat in a gene on the short arm of chromosome 12. The repeat size varied from 7-23 in normal individuals. In patients one allele was expanded to between 49-75 repeats or occasionally even more. Expansion was usually associated with paternal transmission and only occasionally with maternal transmission. Repeat size showed a close correlation with age of onset of symptoms and disease severity. We conclude that DRPLA is the seventh genetic disorder known to be associated with expansion of an unstable trinucleotide repeat.