Leptomeningeal collaterals regulate reperfusion in ischemic stroke and rescue the brain from futile recanalization

Recanalization is the mainstay of ischemic stroke treatment. However, even with timely clot removal, many stroke patients recover poorly. Leptomeningeal collaterals (LMCs) are pial anastomotic vessels with yet-unknown functions. We applied laser speckle imaging, ultrafast ultrasound, and two-photon microscopy in a thrombin-based mouse model of stroke and fibrinolytic treatment to show that LMCs maintain cerebral autoregulation and allow for gradual reperfusion, resulting in small infarcts. In mice with poor LMCs, distal arterial segments collapse, and deleterious hyperemia causes hemorrhage and mortality after recanalization. In silico analyses confirm the relevance of LMCs for preserving perfusion in the ischemic region. Accordingly, in stroke patients with poor collaterals undergoing thrombectomy, rapid reperfusion resulted in hemorrhagic transformation and unfavorable recovery. Thus, we identify LMCs as key components regulating reperfusion and preventing futile recanalization after stroke. Future therapeutic interventions should aim to enhance collateral function, allowing for beneficial reperfusion after stroke.

Assessment of Fitbit Charge 4 for sleep stage and heart rate monitoring against polysomnography and during home monitoring in Huntington's disease

STUDY OBJECTIVES

Wearable devices, monitoring sleep stages and heart rate (HR), bring the potential for longitudinal sleep monitoring in patients with neurodegenerative diseases. Sleep quality reduces with disease progression in Huntington's disease (HD). However, the involuntary movements characteristic of HD may affect the accuracy of wrist-worn devices. This study compares sleep stage and heart rate data from the Fitbit Charge 4 (FB) against polysomnography (PSG) in participants with HD.

METHODS

Ten participants with manifest HD wore a FB during overnight hospital-based PSG, and for nine of these participants continued to wear the FB for seven nights at home. Sleep stages (30s epochs) and minute-by-minute HR were extracted and compared against PSG data.

RESULTS

FB-estimated total sleep and wake times, and sleep stage times were in good agreement with PSG, with intra-class correlations 0.79-0.96. However, poor agreement was observed for Wake After Sleep Onset, and the number of awakenings. FB detected wake with 68.6±15.5% sensitivity and 93.7±2.5% specificity, rapid eye movement (REM) sleep with high sensitivity and specificity (78.7±31.9%, 95.6±2.3%), and deep sleep with lower sensitivity but high specificity (56.4±28.8%, 95.0±4.8%). FB HR was strongly correlated with PSG, and the mean absolute error between FB and PSG HR data was 1.16 ± 0.42 bpm. At home, longer sleep and shorter wake times were observed compared to hospital data, while percentage sleep stage times were consistent with hospital data.

CONCLUSIONS

Results suggest the potential for long-term monitoring of sleep patterns using wrist-worn wearable devices as part of symptom management in HD.

Safety and effectiveness of IV Thrombolysis in retinal artery occlusion: A multicenter retrospective cohort study

BACKGROUND

Retinal artery occlusion (RAO) may lead to irreversible blindness. For acute RAO, intravenous thrombolysis (IVT) can be considered as treatment. However, due to the rarity of RAO, data about IVT safety and effectiveness is limited.

METHODS

From the multicenter database ThRombolysis for Ischemic Stroke Patients (TRISP), we retrospectively analyzed visual acuity (VA) at baseline and within 3 months in IVT and non-IVT treated RAO patients. Primary outcome was difference of VA between baseline and follow up (∆VA). Secondary outcomes were rates of visual recovery (defined as improvement of VA ⩾ 0.3 logMAR), and safety (symptomatic intracranial hemorrhage (sICH) according to ECASS II criteria, asymptomatic intracranial hemorrhage (ICH) and major extracranial bleeding). Statistical analysis was performed using parametric tests and a linear regression model adjusted for age, sex and baseline VA.

RESULTS

We screened 200 patients with acute RAO and included 47 IVT and 34 non-IVT patients with complete information about recovery of vision. Visual Acuity at follow up significantly improved compared to baseline in IVT patients (∆VA 0.5 ± 0.8, p < 0.001) and non-IVT patients (∆VA 0.40 ± 1.1, p < 0.05). No significant differences in ∆VA and visual recovery rate were found between groups at follow up. Two asymptomatic ICH (4%) and one (2%) major extracranial bleeding (intraocular bleeding) occurred in the IVT group, while no bleeding events were reported in the non-IVT group.

CONCLUSION

Our study provides real-life data from the largest cohort of IVT treated RAO patients published so far. While there is no evidence for superiority of IVT compared to conservative treatment, bleeding rates were low. A randomized controlled trial and standardized outcome assessments in RAO patients are justified to assess the net benefit of IVT in RAO.

Tranexamic Acid for Intracerebral Hemorrhage in Patients on Non-Vitamin K Antagonist Oral Anticoagulants (TICH-NOAC): A Multicenter, Randomized, Placebo-Controlled, Phase 2 Trial

BACKGROUND

Evidence-based hemostatic treatment for intracerebral hemorrhage (ICH) associated with non-vitamin K antagonist oral anticoagulants (NOACs) is lacking. Tranexamic acid (TXA) is an antifibrinolytic drug potentially limiting hematoma expansion. We aimed to assess the efficacy and safety of TXA in NOAC-ICH.

METHODS

We performed a double-blind, randomized, placebo-controlled trial at 6 Swiss stroke centers. Patients with NOAC-ICH within 12 hours of symptom onset and 48 hours of last NOAC intake were randomized (1:1) to receive either intravenous TXA (1 g over 10 minutes followed by 1 g over 8 hours) or matching placebo in addition to standard medical care via a centralized Web-based procedure with minimization on key prognostic factors. All participants and investigators were masked to treatment allocation. Primary outcome was hematoma expansion, defined as ≥33% relative or ≥6 mL absolute volume increase at 24 hours and analyzed using logistic regression adjusted for baseline hematoma volume on an intention-to-treat basis.

RESULTS

Between December 12, 2016, and September 30, 2021, we randomized 63 patients (median age, 82 years [interquartile range, 76-86]; 40% women; median hematoma volume, 11.5 [4.8-27.4] mL) of the 109 intended sample size before premature trial discontinuation due to exhausted funding. The primary outcome did not differ between TXA (n=32) and placebo (n=31) arms (12 [38%] versus 14 [45%]; adjusted odds ratio, 0.63 [95% CI, 0.22-1.82]; P=0.40). There was a signal for interaction with onset-to-treatment time (Pinteraction=0.024), favoring TXA when administered within 6 hours of symptom onset. Between the TXA and placebo arms, the proportion of participants who died (15 [47%] versus 13 [42%]; adjusted odds ratio, 1.07 [0.37-3.04]; P=0.91) or had major thromboembolic complications within 90 days (4 [13%] versus 2 [6%]; odds ratio, 1.86 [0.37-9.50]; P=0.45) did not differ. All thromboembolic events occurred at least 2 weeks after study treatment, exclusively in participants not restarted on oral anticoagulation.

CONCLUSIONS

In a smaller-than-intended NOAC-ICH patient sample, we found no evidence that TXA prevents hematoma expansion, but there were no major safety concerns. Larger trials on hemostatic treatments targeting an early treatment window are needed for NOAC-ICH.

REGISTRATION

URL: https://clinicaltrials.gov; Unique identifier: NCT02866838.

Omega-3 Fatty Acids and Heart Rhythm, Rate, and Variability in Atrial Fibrillation

Background Previous randomized control trials showed mixed results concerning the effect of omega-3 fatty acids (n-3 FAs) on atrial fibrillation (AF). The associations of n-3 FA blood levels with heart rhythm in patients with established AF are unknown. The goal of this study was to assess the associations of total and individual n-3 FA blood levels with AF type (paroxysmal versus nonparoxysmal), heart rate (HR), and HR variability in patients with AF. Methods and Results Total n-3 FAs, eicosapentaenoic acid, docosahexaenoic acid, docosapentaenoic acid, and alpha-linolenic acid blood levels were determined in 1969 patients with known AF from the SWISS-AF (Swiss Atrial Fibrillation cohort). Individual and total n-3 FAs were correlated with type of AF, HR, and HR variability using standard logistic and linear regression, adjusted for potential confounders. Only a mild association with nonparoxysmal AF was found with total n-3 FA (odds ratio [OR], 0.97 [95% CI, 0.89-1.05]) and docosahexaenoic acid (OR, 0.93 [95% CI, 0.82-1.06]), whereas other individual n-3 FAs showed no association with nonparoxysmal AF. Higher total n-3 FAs (estimate 0.99 [95% CI, 0.98-1.00]) and higher docosahexaenoic acid (0.99 [95% CI, 0.97-1.00]) tended to be associated with slower HR in multivariate analysis. Docosapentaenoic acid was associated with a lower HR variability triangular index (0.94 [95% CI, 0.89-0.99]). Conclusions We found no strong evidence for an association of n-3 FA blood levels with AF type, but higher total n-3 FA levels and docosahexaenoic acid might correlate with lower HR, and docosapentaenoic acid with a lower HR variability triangular index.

Recanalization Therapies for Large Vessel Occlusion Due to Cervical Artery Dissection: A Cohort Study of the EVA-TRISP Collaboration

BACKGROUND AND PURPOSE

This study aimed to investigate the effect of endovascular treatment (EVT, with or without intravenous thrombolysis [IVT]) versus IVT alone on outcomes in patients with acute ischemic stroke (AIS) and intracranial large vessel occlusion (LVO) attributable to cervical artery dissection (CeAD).

METHODS

This multinational cohort study was conducted based on prospectively collected data from the EVA-TRISP (EndoVAscular treatment and ThRombolysis for Ischemic Stroke Patients) collaboration. Consecutive patients (2015-2019) with AIS-LVO attributable to CeAD treated with EVT and/or IVT were included. Primary outcome measures were (1) favorable 3-month outcome (modified Rankin Scale score 0-2) and (2) complete recanalization (thrombolysis in cerebral infarction scale 2b/3). Odds ratios with 95% confidence intervals (OR [95% CI]) from logistic regression models were calculated (unadjusted, adjusted). Secondary analyses were performed in the patients with LVO in the anterior circulation (LVOant) including propensity score matching.

RESULTS

Among 290 patients, 222 (76.6%) had EVT and 68 (23.4%) IVT alone. EVT-treated patients had more severe strokes (National Institutes of Health Stroke Scale score, median [interquartile range]: 14 [10-19] vs. 4 [2-7], P<0.001). The frequency of favorable 3-month outcome did not differ significantly between both groups (EVT: 64.0% vs. IVT: 86.8%; ORadjusted 0.56 [0.24-1.32]). EVT was associated with higher rates of recanalization (80.5% vs. 40.7%; ORadjusted 8.85 [4.28-18.29]) compared to IVT. All secondary analyses showed higher recanalization rates in the EVT-group, which however never translated into better functional outcome rates compared to the IVT-group.

CONCLUSION

We observed no signal of superiority of EVT over IVT regarding functional outcome in CeAD-patients with AIS and LVO despite higher rates of complete recanalization with EVT. Whether pathophysiological CeAD-characteristics or their younger age might explain this observation deserves further research.

Safety and Outcome of Revascularization Treatment in Patients With Acute Ischemic Stroke and COVID-19: The Global COVID-19 Stroke Registry

BACKGROUND AND OBJECTIVES

COVID-19-related inflammation, endothelial dysfunction, and coagulopathy may increase the bleeding risk and lower the efficacy of revascularization treatments in patients with acute ischemic stroke (AIS). We aimed to evaluate the safety and outcomes of revascularization treatments in patients with AIS and COVID-19.

METHODS

This was a retrospective multicenter cohort study of consecutive patients with AIS receiving intravenous thrombolysis (IVT) and/or endovascular treatment (EVT) between March 2020 and June 2021 tested for severe acute respiratory syndrome coronavirus 2 infection. With a doubly robust model combining propensity score weighting and multivariate regression, we studied the association of COVID-19 with intracranial bleeding complications and clinical outcomes. Subgroup analyses were performed according to treatment groups (IVT-only and EVT).

RESULTS

Of a total of 15,128 included patients from 105 centers, 853 (5.6%) were diagnosed with COVID-19; of those, 5,848 (38.7%) patients received IVT-only and 9,280 (61.3%) EVT (with or without IVT). Patients with COVID-19 had a higher rate of symptomatic intracerebral hemorrhage (SICH) (adjusted OR 1.53; 95% CI 1.16-2.01), symptomatic subarachnoid hemorrhage (SSAH) (OR 1.80; 95% CI 1.20-2.69), SICH and/or SSAH combined (OR 1.56; 95% CI 1.23-1.99), 24-hour mortality (OR 2.47; 95% CI 1.58-3.86), and 3-month mortality (OR 1.88; 95% CI 1.52-2.33). Patients with COVID-19 also had an unfavorable shift in the distribution of the modified Rankin score at 3 months (OR 1.42; 95% CI 1.26-1.60).

DISCUSSION

Patients with AIS and COVID-19 showed higher rates of intracranial bleeding complications and worse clinical outcomes after revascularization treatments than contemporaneous non-COVID-19 patients receiving treatment. Current available data do not allow direct conclusions to be drawn on the effectiveness of revascularization treatments in patients with COVID-19 or to establish different treatment recommendations in this subgroup of patients with ischemic stroke. Our findings can be taken into consideration for treatment decisions, patient monitoring, and establishing prognosis.

TRIAL REGISTRATION INFORMATION

The study was registered under ClinicalTrials.gov identifier NCT04895462.

Tandem occlusions involving the internal carotid and anterior cerebral arteries-A rare form of stroke: Results from the multicenter EVATRISP collaboration study

Background

Patients with stroke secondary to isolated anterior cerebral artery (ACA) occlusions have poor outcomes. Whether tandem occlusions (TO) of the extracranial internal carotid (ICA) and the ACA carry even worse outcomes that remain unknown.

Methods

Patients with TO involving ICA and ACA occlusions were identified from 14 participating centers from the EndoVascular treatment And ThRombolysis in Ischemic Stroke Patients (EVATRISP) project which is a multicenter, observational, cohort study with prospective accrual of data followed by retrospective data analysis. Patients with isolated ACA stroke served as controls.

Results

Included were 92 patients with isolated ACA and 16 patients with ICA-ACA TO stroke. On univariate analyses, patients with TO had more severe strokes on admission [median NIHSS (IQR) 13.5 (9-21) vs. 8 (5-12), p = 0.003] and were more often treated with thrombectomy (81 vs. 40%, p = 0.002). Mortality rates were higher among TO patients (31 vs. 11%, p = 0.03). Rates of favorable functional outcomes were numerically lower among TO patients (38 vs. 60%) but the difference was not statistically significant (p = 0.09). On multivariate analyses, the presence of TO did not modify the chances for favorable outcomes.

Conclusion

TO stroke with ICA and isolated ACA involvement is rare and results in more severe initial neurological deficits and higher mortality compared to those seen in patients with isolated ACA stroke.

Outcomes after reperfusion therapies in patients with ACA stroke: A multicenter cohort study from the EVATRISP collaboration

BACKGROUND

Patients with stroke secondary to occlusions of the anterior cerebral artery (ACA) often have poor outcomes. The optimal acute therapeutic intervention for these patients remains unknown.

METHODS

Patients with isolated ACA-stroke were identified from 10 centers participating in the EndoVascular treatment And ThRombolysis in Ischemic Stroke Patients (EVATRISP) prospective registry. Patients treated with endovascular thrombectomy (EVT) were compared to those treated with intravenous thrombolysis (IVT). Odds ratios with 95% confidence intervals (OR; 95%CI) were calculated using multivariate regression analysis.

RESULTS

Included were 92 patients with ACA-stroke. Of the 92 ACA patients, 55 (60%) were treated with IVT only and 37 (40%) with EVT (±bridging IVT). ACA patients treated with EVT had more often wake-up stroke (24% vs. 6%, p = 0.044) and proximal ACA occlusions (43% vs. 24%, p = 0.047) and tended to have higher stroke severity on admission [NIHSS: 10.0 vs 7.0, p = 0.054). However, odds for favorable outcome, mortality or symptomatic intracranial hemorrhage did not differ significantly between both groups. Exploration of the effect of clot location inside the ACA showed that in patients with A1 or A2/A3 ACA occlusions the chances of favorable outcome were not influenced by treatment allocation to IVT or EVT.

DISCUSSION

Treatment with either IVT or EVT could be safe with similar effect in patients with ACA-strokes and these effects may be independent of clot location within the occluded ACA.

Maintenance of Acute Stroke Care Service During the COVID-19 Pandemic Lockdown

Supplemental Digital Content is available in the text.

Background and Purpose:

Timely reperfusion is an important goal in treatment of eligible patients with acute ischemic stroke. However, during the coronavirus disease 2019 (COVID-19) pandemic, prehospital and in-hospital emergency procedures faced unprecedented challenges, which might have caused a decline in the number of acute reperfusion therapy applied and led to a worsening of key quality measures for this treatment during lockdown.

Methods:

This prospective multicenter cohort study used data from the TRISP (Thrombolysis in Ischemic Stroke Patients) registry of patients with acute ischemic stroke treated with reperfusion therapies, that is, intravenous thrombolysis or endovascular therapy. We compared prehospital and in-hospital time-based performance measures (stroke-onset-to-admission, admission-to-treatment, admission-to-image, and image-to-treatment time) during the first 6 weeks after announcement of lockdown (lockdown period) with the same period in 2019 (reference period). Secondary outcomes included stroke severity (National Institutes of Health Stroke Scale) after 24 hours and occurrence of symptomatic intracranial hemorrhage (following the ECASS [European-Australasian Acute Stroke Study]-II criteria).

Results:

Across 20 stroke centers, 540 patients were treated with intravenous thrombolysis/endovascular therapy during lockdown period compared with 578 patients during reference period (−7% [95% CI, 5%–9%]). Performance measures did not change significantly during the lockdown period (2020/2019 minutes median: onset-to-admission 133/145; admission-to-treatment 51/48). Same was true for admission-to-image (20/19) and image-to-treatment (31/30) time in patients with available time of first image (n=871, 77.9%). Median National Institutes of Health Stroke Scale on admission (2020/2019: 11/11) and after 24 hours (2020/2019: 6/5) and percentage of symptomatic intracranial hemorrhage (2020/2019: 6.2/5.7) did not differ significantly between both periods.

Conclusions:

The COVID-19 pandemic lockdown resulted in a mild decline in the number of patients with stroke treated with acute reperfusion therapies. More importantly, the solid stability of key quality performance measures between the 2020 and 2019 period may indicate resilience of acute stroke care service during the lockdown, at least in well-established European stroke centers.

Motivational Profiling of League of Legends Players

Player motivation is a key research area within games research, with the aim of understanding how the motivation of players is related to their experience and behavior in the game. We present the results of a cross-sectional study with data from 750 players of League of Legends, a popular Multiplayer Online Battle Arena game. Based on the motivational regulations posited by Self-Determination Theory and Latent Profile Analysis, we identify four distinct motivational profiles, which differ with regards to player experience and, to a lesser extent, in-game behavior. While the more self-determined profiles “Intrinsic” and “Autonomous” report mainly positive experience-related outcomes, a considerable part of the player base does not. Players of the “Amotivated” and “External” profile derive less enjoyment, experience more negative affect and tension, and score lower on vitality, indicating game engagement that is potentially detrimental to players' well-being. With regards to game metrics, minor differences in the rate of assists in unranked matches and performance indicators were observed between profiles. This strengthens the notion that differences in experiences are not necessarily reflected in differences in behavioral game metrics. Our findings provide insights into the interplay of player motivation, experience, and in-game behavior, contributing to a more nuanced understanding of player-computer interaction.

Sensorimotor stroke alters hippocampo-thalamic network activity

Many stroke survivors experience persisting episodic memory disturbances. Since hippocampal and para-hippocampal areas are usually spared from the infarcted area, alterations of memory processing networks remote from the ischemic brain region might be responsible for the observed clinical symptoms. To pinpoint changes in activity of hippocampal connections and their role in post-stroke cognitive impairment, we induced ischemic stroke by occlusion of the middle cerebral artery (MCAO) in adult rats and analyzed the functional and structural consequences using activity-dependent manganese (Mn²⁺) enhanced MRI (MEMRI) along with behavioral and histopathological analysis. MCAO caused stroke lesions of variable extent along with sensorimotor and cognitive deficits. Direct hippocampal injury occurred in some rats, but was no prerequisite for cognitive impairment. In healthy rats, injection of Mn²⁺ into the entorhinal cortex resulted in distribution of the tracer within the hippocampal subfields into the lateral septal nuclei. In MCAO rats, Mn²⁺ accumulated in the ipsilateral thalamus. Histopathological analysis revealed secondary thalamic degeneration 28 days after stroke. Our findings provide in vivo evidence that remote sensorimotor stroke modifies the activity of hippocampal-thalamic networks. In addition to potentially reversible alterations in signaling of these connections, structural damage of the thalamus likely reinforces dysfunction of hippocampal-thalamic circuitries.

Task-Specific Motor Rehabilitation Therapy After Stroke Improves Performance in a Different Motor Task: Translational Evidence

While the stroke survivor with a motor deficit strives for recovery of all aspects of daily life movements, neurorehabilitation training is often task specific and does not generalize to movements other than the ones trained. In rodent models of post-stroke recovery, this problem is poorly investigated as the training task is often the same as the one that measures motor function. The present study investigated whether motor training by pellet reaching translates into enhancement of different motor functions in rats after stroke. Adult rats were subjected to 60-min middle cerebral artery occlusion (MCAO). Five days after stroke, animals received either training consisting of 7 days of pellet reaching with the affected forelimb (n = 18) or no training (n = 18). Sensorimotor deficits were assessed using the sticky tape test and a composite neuroscore. Infarct volumes were measured by T2-weighted MRI on day 28. Both groups of rats showed similar lesion volume and forelimb impairment after stroke. Trained animals improved in the sticky tape test after day 7 post-stroke reaching peak performance on day 14. More reaching attempts during rehabilitation were associated with a better performance in the sticky tape removal time. Task-oriented motor training generalizes to other motor functions after experimental stroke. Training intensity correlates with recovery.

Stimulation of cellular sphingomyelin import by the chemokine connective tissue-activating peptide III

The selective import of phospholipids into cells could be mediated by proteins secreted from the cells into the extracellular compartment. We observed that the supernatants obtained from suspensions of thrombin-activated platelets stimulated the exchange of pyrene (py)-labeled sphingomyelin between lipid vesicles in vitro. The proteins with sphingomyelin transfer activity were purified and identified as the chemokine connective tissue-activating peptide III (CTAP-III) and platelet basic protein. Isolated CTAP-III stimulated the exchange of py-sphingomyelin between lipid vesicles but did not affect the translocations of py-labeled phosphatidylcholine and phosphatidylethanolamine. CTAP-III rapidly increased the transfer of py-sphingomyelin from low density lipoproteins into peripheral blood lymphocytes, other immune cells, and fibroblasts. In the presence of heparin, CTAP-III was unable to insert sphingomyelin into the peripheral blood lymphocytes. The activation energy of the py-sphingomyelin transfer suggested that the translocation proceeded entirely in a hydrophobic environment. [(3)H]Sphingomyelin transferred to the cells by CTAP-III was hydrolyzed to [(3)H]ceramide and [(3)H]sphingosine after activation with tumor necrosis factor alpha. The generation of the [(3)H]sphingolipid messengers was catalyzed by acid sphingomyelinase. Our results identify CTAP-III as the first mediator of the selective (endocytosis-independent) cellular import of sphingomyelin allowing the paracrine modulation of the sphingolipid signaling.

Serum IgG, IgM, and IgA reactivity to human papillomavirus types 11 and 6 virus-like particles in different gynecologic patient groups

Serum samples from several groups of patients attending a gynecology clinic were analyzed by ELISA for specific antibodies recognizing surface epitopes on intact human papillomavirus (HPV) types 6 and 11 L1 virus-like particles (VLPs) that were synthesized in vitro. In these samples, positive IgG and IgM reactivities to HPV-11 L1 VLPs were, respectively, 12% and 6% for 87 controls, 46% and 67% for 79 condyloma patients, 30% and 64% for 72 cervical intraepithelial neoplasia patients, 16% and 19% for 63 pregnant women at time of delivery, and 5% and 0 in their 63 newborns. IgA reactivities were low and not significantly different. The prevalence of IgG-positivity in HPV-6/11 DNA-positive patients increased from 46% with HPV-11 L1 VLPs to 76% when the sera were additionally screened with HPV-6 L1 VLPs. These data show that HPV-6 and -11 L1 VLPs are effective antigens for serologic studies and they detect type-specific antibodies.

Pride and mastery in children with autism

The goal of this study was to compare expressions of pride and mastery in samples of preschool autistic, mentally retarded and normal children. A paradigm was used in which children completed developmentally appropriate puzzles, both with and without praise. Results indicated that compared to the other children, as many autistic children smiled upon completion of the task, but many fewer looked up to share their pleasure with the parent or experimenter or drew attention to the task. Moreover, significantly more autistic children showed avoidant responses, particularly in response to praise. These findings are discussed in terms of theoretical issues regarding the development of pride and mastery in children with significant social deficiencies.

Cytokine regulation of the balance between alloindifferent and allospecific suppressor induction in mixed lymphocyte cultures

The effects of exogenous cytokines on the generation of alloindifferent, MHC-unrestricted suppressive activity early on in mixed lymphocyte culture interactions have been investigated. Interleukin 4 strongly blocked the generation of suppression, whereas IL-1, IL-2, and IL-6 enhanced it to some extent. Tumor necrosis factor-alpha, interferons-alpha and -gamma, granulocyte/macrophage colony-stimulating factor, granulocyte CSF, IL-3 and IL-5, and a number of combinations of these factors were without effect in this system. Insofar as the alloindifferent suppression studied here also inhibited the development of allospecific, MHC restricted suppressive activity later in MLC, reduction by IL-4 of its development may have relevance for the use of this cytokine to facilitate the induction of specific suppressor cell-mediated transplantation tolerance in vivo.

Structural organization and sequence of the homeotic gene Antennapedia of Drosophila melanogaster

The structure of the Drosophila melanogaster Antennapedia (Antp) gene has been investigated by the isolation and sequencing of different cDNAs and genomic clones. Northern analysis, S1 mapping and primer extension experiments reveal a complex and unusual gene structure. The gene is composed of two promoters, eight exons spanning >100 kb, and two termination processing regions. Four major polyadenylated transcripts were found, two of them starting at a second internal promoter in front of exon 3. All four transcripts have extremely long untranslated leader and trailer sequences in the range of 1-2 kb. Despite the complex transcriptional organization, the open reading frame is the same in all transcripts, and starts in exon 5 giving rise to a protein of mol. wt. 42 800. The putative protein is rich in glutamine (18%) and proline (10%). The homeobox, a region which previously has been shown to be highly conserved among homeotic genes, is contained in the open reading frame and located in the last exon. Functional implications of the complex structure with respect to development and its relation to the mutant phenotypes are discussed.

Combined pharmaco-EEG and pharmacopsychological study to estimate CNS effects of ketanserin in hypertensive patients

When developing a new compound, potential side effects on the central nervous system (CNS) should be systematically investigated to determine the drug's safety, e.g., in respect of operating machinery or driving a car. The present study investigated CNS effects of ketanserin, a newly developed S2-serotonergic antagonist, in hypertensive patients. A multidimensional research strategy was used combining pharmaco-EEG and pharmacopsychological methods. The investigation consisted of two separate double-blind, randomized, and placebo-controlled studies, which were, however, planned together and in part included the same patients. The first study was carried out in 2 X 24 patients receiving chronic treatment with 2 X 20 mg ketanserin for 2 weeks, followed by 2 X 40 mg for a further 3 weeks. The second study was performed in 2 X 20 patients after subacute administration of 20 mg twice daily for six days. A multidimensional research strategy was employed to investigate CNS effects on functional and performance measures. Vigilance-related parameters, such as the alpha slow wave index and the absolute delta power, were assessed with pharmaco electroencephalography. Critical flicker-fusion frequency served as a measure of central sedation. Psychomotor performance and concentration tests were used to detect CNS effects which might impair car-driving ability. In addition, subjective well-being and adverse drug reactions were recorded. Ketanserin proved to be a safe drug to lower blood pressure. Only after chronic treatment were there slight indications that ketanserin could have a sedating and inhibiting action on the CNS. However, the differences between placebo and the ketanserin group, and the alterations within each group, were so minimal that they were not considered clinically relevant. A negative effect of ketanserin on car-driving ability is not very likely. The results show that the model was sensitive enough to detect CNS effects with sufficient certainty.

Cloning of the homeotic Sex combs reduced gene in Drosophila and in situ localization of its transcripts

We have extended our ;chromosomal walk' in the Antennapedia-complex (ANT-C) by isolating overlapping DNA sequences spanning the chromosomal segment between Antennapedia (Antp) and Deformed (Dfd). The transcription units, homeoboxes and M-repeats were mapped within this region. Four transcription units Antp, fushi tarazu (ftz), Sex combs reduced (Scr) and Dfd contain both a homeobox and an M repeat, whereas at least two additional transcription units, x and z, were found to lack these elements. The Scr locus was identified by deletion mapping. It consists of at least two exonic regions separated by a large intron. The homeobox is located in the 3' exon and is 82% homologous to the one in Antp. Scr encodes a major 3.9-kb RNA. A corresponding cDNA clone was used as a probe for in situ hybridization to sections of various embryonic stages. At gastrula stages Scr transcripts accumulate in the posterior head and the anterior thoracic region of the germ band. At later stages a strong accumulation of transcripts is observed in the suboesophageal and the prothoracic ganglion of the ventral nervous system.