Neoadjuvant Immunotherapy in Locally Advanced Mismatch Repair-Deficient Colon Cancer.

BACKGROUND: Mismatch repair-deficient (dMMR) tumors can be found in 10 to 15% of patients with nonmetastatic colon cancer. In these patients, the efficacy of chemotherapy is limited. The use of neoadjuvant immunotherapy has shown promising results, but data from studies of this approach are limited. METHODS: We conducted a phase 2 study in which patients with nonmetastatic, locally advanced, previously untreated dMMR colon cancer were treated with neoadjuvant nivolumab plus ipilimumab. The two primary end points were safety, defined by timely surgery (i.e., ≤2-week delay of planned surgery owing to treatment-related toxic events), and 3-year disease-free survival. Secondary end points included pathological response and results of genomic analyses. RESULTS: Of 115 enrolled patients, 113 (98%; 97.5% confidence interval [CI], 93 to 100) underwent timely surgery; 2 patients had surgery delayed by more than 2 weeks. Grade 3 or 4 immune-related adverse events occurred in 5 patients (4%), and none of the patients discontinued treatment because of adverse events. Among the 111 patients included in the efficacy analysis, a pathological response was observed in 109 (98%; 95% CI, 94 to 100), including 105 (95%) with a major pathological response (defined as ≤10% residual viable tumor) and 75 (68%) with a pathological complete response (0% residual viable tumor). With a median follow-up of 26 months (range, 9 to 65), no patients have had recurrence of disease. CONCLUSIONS: In patients with locally advanced dMMR colon cancer, neoadjuvant nivolumab plus ipilimumab had an acceptable safety profile and led to a pathological response in a high proportion of patients. (Funded by Bristol Myers Squibb; NICHE-2 ClinicalTrials.gov number, NCT03026140.).

Disease severity in subsequent pregnancies with RhD immunization: A nationwide cohort.

BACKGROUND AND OBJECTIVES: To evaluate the severity of haemolytic disease of the foetus and newborn (HDFN) in subsequent pregnancies with RhD immunization and to identify predictive factors for severe disease. MATERIALS AND METHODS: Nationwide prospective cohort study, including all pregnant women with RhD antibodies. All women with at least two pregnancies with RhD antibodies and RhD-positive foetuses were selected. The main outcome measure was the severity of HDFN in the first and subsequent pregnancy at risk. A subgroup analysis was performed for the group of women where RhD antibodies developed after giving birth to an RhD-positive child and thus after receiving anti-D at least twice (group A) or during the first pregnancy at risk for immunization (group B). RESULTS: Sixty-two RhD immunized women with a total of 150 RhD-positive children were included. The severity of HDFN increased for the whole group significantly in the subsequent pregnancy (p < 0.001), although it remained equal or even decreased in 44% of women. When antibodies were already detected at first trimester screening in the first immunized pregnancy, after giving birth to an RhD-positive child (group A), severe HDFN in the next pregnancy was uncommon (22%). Especially when no therapy or only non-intensive phototherapy was indicated during the first immunized pregnancy (6%) or if the antibody-dependent cell-mediated cytotoxicity result remained <10%. Contrarily, women with a negative first trimester screening and RhD antibodies detected later during the first pregnancy of an RhD-positive child (group B), often before they had ever received anti-D prophylaxis, were most prone for severe disease in a subsequent pregnancy (48%). CONCLUSION: RhD-mediated HDFN in a subsequent pregnancy is generally more severe than in the first pregnancy at risk and can be estimated using moment of antibody detection and severity in the first immunized pregnancy. Women developing antibodies in their first pregnancy of an RhD-positive child are at highest risk of severe disease in the next pregnancy.

Pre-job loss grief reactions and work attachment among sick-listed employees: Introduction of the imminent Job Loss Scale.

BACKGROUND: With this study, we aimed to explore the emotional experiences of sick-listed employees facing imminent job loss, as this emotional distress may hinder successful job search outcomes. The study had two objectives: (1) to develop and validate the Imminent Job Loss Scale (IJLS) for assessing pre-job loss grief reactions and (2) to examine its relationship to work attachment. METHODS: Development of the 9-item IJLS was carried out using feedback from an expert panel, consisting of five academic experts in grief and labour, five re-integration specialists, and five sick-listed employees facing imminent job loss. The psychometric properties of the IJLS were evaluated, and its association with work attachment was examined using data from 200 sick-listed employees facing imminent job loss. RESULTS: The IJLS demonstrated strong internal consistency and temporal stability, distinctiveness from depression and anxiety symptoms, and solid convergent validity. Work-centrality and organizational commitment were positively related to pre-job loss grief reactions, while work engagement and calling showed no significant associations. CONCLUSION: This study provides valuable insights into pre-job loss grief reactions and shows the potential utility of the IJLS for screening and monitoring purposes. Understanding pre-job loss grief reactions can improve the re-integration and job prospects of sick-listed employees. In future research, explorations of these dynamics should continue to provide better support to sick-listed employees during this challenging period.

Dose response relationship between lithium serum levels during pregnancy and birth outcomes.

INTRODUCTION: Lithium use during pregnancy reduces the risk of mood episodes in the perinatal period for women with bipolar disorder. Some previous studies found deleterious effects of intrauterine lithium exposure on birth outcomes, yet little is known about a dose response relationship. The current study investigated the influence of maternal lithium serum levels on birth outcomes. METHODS: This retrospective observational cohort study included women with a bipolar spectrum disorder who were referred to a specialized psychiatric and obstetric outpatient clinic from 2003 to 2019 and used lithium during the entire pregnancy. For 101 pregnancies at least one lithium level during pregnancy was available. A weighted average lithium level was calculated for the entire pregnancy, as well as for each trimester. Detailed information on maternal, obstetric and neonatal outcomes were retrieved from the medical records. Linear and logistic regression models were used to investigate the association between weighted average lithium level and pregnancy duration, birth weight percentiles, preterm birth and large for gestational age births (LGA). In subsequent exploratory analyses, we studied the role of thyroid-stimulating hormone (TSH) and thyroxine (T4) as a mediator in the found associations. RESULTS: The weighted average lithium serum level during pregnancy was negatively associated with pregnancy duration and positively with preterm birth, but not with birth weight percentile or LGA. In exploratory analyses, TSH and T4 did not mediate the association between average lithium serum level and pregnancy duration. CONCLUSION: The results of this cohort study during pregnancy indicate a dose response relationship between maternal lithium serum levels and pregnancy duration.

Prevalence of neoplasia at colonoscopy among testicular cancer survivors treated with platinum-based chemotherapy.

Testicular cancer survivors (TCS) treated with platinum-based chemotherapy have an increased risk of colorectal cancer (CRC). We determined the yield of colonoscopy in TCS to assess its potential in reducing CRC incidence and mortality. We conducted a colonoscopy screening study among TCS in four Dutch hospitals to assess the yield of colorectal neoplasia. Neoplasia was defined as adenomas, serrated polyps (SPs), advanced adenomas (AAs: ≥10 mm diameter, high-grade dysplasia or ≥25% villous component), advanced serrated polyps (ASPs: ≥10 mm diameter or dysplasia) or CRC. Advanced neoplasia (AN) was defined as AA, ASP or CRC. Colonoscopy yield was compared to average-risk American males who underwent screening colonoscopy (n = 24,193) using a propensity score matched analysis, adjusted for age, smoking status, alcohol consumption and body mass index. A total of 137 TCS underwent colonoscopy. Median age was 50 years among TCS (IQR 43-57) vs 55 years (IQR 51-62) among American controls. A total of 126 TCS were matched to 602 controls. The prevalence of AN was higher in TCS than in controls (8.7% vs 1.7%; P = .0002). Nonadvanced adenomas and SPs were detected in 45.2% of TCS vs 5.5% of controls (P < .0001). No lesions were detected in 46.0% of TCS vs 92.9% of controls (P < .0001). TCS treated with platinum-based chemotherapy have a higher prevalence of neoplasia and AN than matched controls. These results support our hypothesis that platinum-based chemotherapy increases the risk of colorectal neoplasia in TCS. Cost-effectiveness studies are warranted to ascertain the threshold of AN prevalence that justifies the recommendation of colonoscopy for TCS.

Course of objectively measured physical activity and sleep in postmenopausal breast cancer survivors during the COVID-19 pandemic: A 1-year follow-up.

BACKGROUND: As physical inactivity and poor sleep quality may impose additional risk for cancer recurrence and overall mortality in postmenopausal breast cancer (PMBC) survivors, it is important to gain insight into the effect of the COVID-19 pandemic on their physical activity (PA) and sleep level. OBJECTIVE: This study aimed to assess the course of their physical activity (PA) and sleep throughout governmental measures against COVID-19 during 12 months of the COVID-19 pandemic. METHODS: PMBC survivors (n = 96) wore an ActiGraph wGT3X-BT for seven consecutive days at 12 and 18 months after diagnosis and additional measurements were taken after onset of the second (partial) COVID-19 lockdown. Longitudinal data was categorized into four timepoints: before onset of COVID-19 (T1), during the initial lockdown (T2), in between initial and second lockdown (T3), and during the second lockdown (T4). General linear mixed effects models assessed differences in moderate-to-vigorous physical activity (MVPA) per day, total minutes of PA per day, average acceleration, intensity gradient, sleep efficiency, and sleep duration over time. RESULTS: Levels of MVPA per day before COVID-19 were low (Median = 20.9 min/day (IQR = 10.8;36.2)), and time spent physically active was most often in light intensity, which remained stable throughout the pandemic. Sleep duration (Median = 442.8 min/night (IQR = 418.3;478.0)) and efficiency (85.9% (IQR = 79.6;88.4)) was sufficient before COVID-19 and showed stability over time. CONCLUSIONS: Low levels of PA with mostly light intensity, and adequate sleep efficiency and duration were observed before COVID in PMBC survivors. This was not further affected by COVID-19 governmental measures.

Towards Response ADAptive Radiotherapy for organ preservation for intermediate-risk rectal cancer (preRADAR): protocol of a phase I dose-escalation trial.

INTRODUCTION: Organ preservation is associated with superior functional outcome and quality of life (QoL) compared with total mesorectal excision (TME) for rectal cancer. Only 10% of patients are eligible for organ preservation following short-course radiotherapy (SCRT, 25 Gy in five fractions) and a prolonged interval (4-8 weeks) to response evaluation. The organ preservation rate could potentially be increased by dose-escalated radiotherapy. Online adaptive magnetic resonance-guided radiotherapy (MRgRT) is anticipated to reduce radiation-induced toxicity and enable radiotherapy dose escalation. This trial aims to establish the maximum tolerated dose (MTD) of dose-escalated SCRT using online adaptive MRgRT. METHODS AND ANALYSIS: The preRADAR is a multicentre phase I trial with a 6+3 dose-escalation design. Patients with intermediate-risk rectal cancer (cT3c-d(MRF-)N1M0 or cT1-3(MRF-)N1M0) interested in organ preservation are eligible. Patients are treated with a radiotherapy boost of 2×5 Gy (level 0), 3×5 Gy (level 1), 4×5 Gy (level 2) or 5×5 Gy (level 3) on the gross tumour volume in the week following standard SCRT using online adaptive MRgRT. The trial starts on dose level 1. The primary endpoint is the MTD based on the incidence of dose-limiting toxicity (DLT) per dose level. DLT is a composite of maximum one in nine severe radiation-induced toxicities and maximum one in three severe postoperative complications, in patients treated with TME or local excision within 26 weeks following start of treatment. Secondary endpoints include the organ preservation rate, non-DLT, oncological outcomes, patient-reported QoL and functional outcomes up to 2 years following start of treatment. Imaging and laboratory biomarkers are explored for early response prediction. ETHICS AND DISSEMINATION: The trial protocol has been approved by the Medical Ethics Committee of the University Medical Centre Utrecht. The primary and secondary trial results will be published in international peer-reviewed journals. TRIAL REGISTRATION NUMBER: WHO International Clinical Trials Registry (NL8997; https://trialsearch.who.int).

Brain development after intrauterine exposure to lithium: A magnetic resonance imaging study in school-age children.

OBJECTIVE: Lithium is often continued during pregnancy to reduce the risk of perinatal mood episodes for women with bipolar disorder. However, little is known about the effect of intrauterine lithium exposure on brain development. The aim of this study was to investigate brain structure in children after intrauterine exposure to lithium. METHODS: Participants were offspring, aged 8-14 years, of women with a diagnosis of bipolar spectrum disorder. In total, 63 children participated in the study: 30 with and 33 without intrauterine exposure to lithium. Global brain volume outcomes and white matter integrity were assessed using structural MRI and diffusion tensor imaging, respectively. Primary outcomes were total brain, cortical and subcortical gray matter, cortical white matter, lateral ventricles, cerebellum, hippocampus and amygdala volumes, cortical thickness, cortical surface area and global fractional anisotropy, and mean diffusivity. To assess how our data compared to the general population, global brain volumes were compared to data from the Generation R study (N = 3243). RESULTS: In our primary analyses, we found no statistically significant associations between intrauterine exposure to lithium and structural brain measures. There was a non-significant trend toward reduced subcortical gray matter volume. Compared to the general population, lithium-exposed children showed reduced subcortical gray and cortical white matter volumes. CONCLUSION: We found no differences in brain structure between lithium-exposed and non-lithium-exposed children aged 8-14 years following correction for multiple testing. While a rare population to study, future and likely multi-site studies with larger datasets are required to validate and extend these initial findings.

Neurodevelopment in school-aged children after intrauterine exposure to antipsychotics.

OBJECTIVE: Antipsychotics are increasingly prescribed in pregnancy, yet little is known about potential long-term developmental effects on children. In this study, we investigated the effect of prenatal antipsychotic exposure on neurodevelopmental functioning in school-aged children. METHODS: We performed a cross-sectional neurodevelopmental assessment of 91 children aged 6-14 years whose mothers had severe mental illness and were either exposed or unexposed to antipsychotic medication during pregnancy. Neurodevelopmental outcomes were assessed using validated neurodevelopmental assessment instruments to examine the child's IQ and global cognitive functioning, and the presence of any psychiatric disorders and/or learning problems in the child was assessed by parental report. RESULTS: No statistically significant associations were found between antipsychotic exposure during pregnancy and either adverse neurodevelopmental outcomes (IQ, neuropsychological function), likelihood of psychiatric diagnosis, or learning problems based on parental report. Analyses were likely limited in power to detect subtler differences in neurodevelopmental functioning because of small sample size and heterogeneity of the sample. CONCLUSIONS: In this exploratory cohort study, intrauterine exposure to antipsychotics was not associated with any adverse effect on IQ or neurodevelopmental functioning in a cohort of school-aged children (6-14 years).

Chimeric efferocytic receptors improve apoptotic cell clearance and alleviate inflammation.

Our bodies turn over billions of cells daily via apoptosis and are in turn cleared by phagocytes via the process of "efferocytosis." Defects in efferocytosis are now linked to various inflammatory diseases. Here, we designed a strategy to boost efferocytosis, denoted "chimeric receptor for efferocytosis" (CHEF). We fused a specific signaling domain within the cytoplasmic adapter protein ELMO1 to the extracellular phosphatidylserine recognition domains of the efferocytic receptors BAI1 or TIM4, generating BELMO and TELMO, respectively. CHEF-expressing phagocytes display a striking increase in efferocytosis. In mouse models of inflammation, BELMO expression attenuates colitis, hepatotoxicity, and nephrotoxicity. In mechanistic studies, BELMO increases ER-resident enzymes and chaperones to overcome protein-folding-associated toxicity, which was further validated in a model of ER-stress-induced renal ischemia-reperfusion injury. Finally, TELMO introduction after onset of kidney injury significantly reduced fibrosis. Collectively, these data advance a concept of chimeric efferocytic receptors to boost efferocytosis and dampen inflammation.

Features on Endoscopy and MRI after Treatment with Contact X-ray Brachytherapy for Rectal Cancer: Explorative Results.

After neoadjuvant (chemo)radiotherapy for rectal cancer, contact X-ray brachytherapy (CXB) can be applied aiming at organ preservation. This explorative study describes the early features on endoscopy and MRI after CXB. Patients treated with CXB following (chemo)radiotherapy and a follow-up of ≥12 months were selected. Endoscopy and MRI were performed every 3 months. Expert readers scored all the images according to structured reporting templates. Thirty-six patients were included, 15 of whom obtained a cCR. On endoscopy, the most frequently observed feature early in follow-up was an ulcer, regardless of whether patients developed a cCR. A flat, white scar and tumor mass were common at 6 months. Focal tumor signal on T2W-MRI and mass-like high signal on DWI were generally absent in patients with a cCR. An ulceration on T2W-MRI and "reactive" mucosal signal on DWI were observed early in follow-up regardless of the final tumor response. The distinction between a cCR and a residual tumor generally can be made at 6 months. Features associated with a residual tumor are tumor mass on endoscopy, focal tumor signal on T2W-MRI, and mass-like high signal on DWI. Early recognition of these features is necessary to identify patients who will not develop a cCR as early as possible.

Early Speech Sound Production and Its Trajectories in Very Preterm Children From 2 to 4 Years of Age.

PURPOSE: Very preterm (VPT) children are at risk for speech and language problems throughout school age. However, little is known about early speech sound production in these children. This study aims to present a detailed description of early speech sound production and its trajectories in VPT children from 2 to 4 years of age. In addition, this study aimed to determine if early speech sound production is associated with speech production and expressive language function at 4 years of age. METHOD: In 63 VPT children (< 32 weeks of gestation, 41 boys, mean gestational age = 28.8 weeks, mean birth weight = 1,135 g), speech sound production was assessed by naturalistic speech analysis at 2 years of corrected age and speech and language function by standardized tests at 4 years of age. RESULTS: Speech sound production was found to be abnormal in 49% of the VPT children at 2 years of age and in 19% at 4 years of age. Four different speech production trajectories from 2 to 4 years of age could be identified: a normal trajectory, an abnormal trajectory, a catch-up trajectory, and a growing-into-deficit trajectory. Early speech production, defined by the number of acquired consonants at 2 years of age, significantly predicted the word production score at 4 years of age and the sentence production score at 4 years of age. CONCLUSIONS: Compared to the general population, an alarmingly high proportion of VPT children showed speech production problems at 2 years of age. About half of these children showed persistent speech problems at 4 years of age. Moreover, these problems were associated with expressive language problems at the age of 4 years. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.19310822.

[Formula: see text]Are multidisciplinary neurodevelopmental profiles of children born very preterm at age 2 relevant to their long-term development? A preliminary study.

To identify distinctive multidisciplinary neurodevelopmental profiles of relatively healthy children born very preterm (VPT) and describe the longitudinal course of these profiles up to age 10. At 2 years of corrected age, 84 children born VPT underwent standardized testing for cognitive, language, speech, motor, behavioral, and auditory nerve function. These data were submitted to factor and cluster analysis. Sixty-one of these children underwent cognitive, language, and behavioral assessment again at age 10. Descriptive statistics were used to analyze longitudinal trajectories for each profile. Four neurodevelopmental profiles were identified at age 2. Profile 1 children (n = 22/26%) had excellent cognitive-language-motor function, normal behavioral and auditory nerve function, but showed an unexpected severe decline up to age 10. Profile 2 children (n = 16/19%) had very low behavioral function, low cognitive-language-motor function, and accelerated auditory nerve function. Their scores remained low up until age 10. Profile 3 children (n = 17/20%) had delayed auditory nerve function, low behavioral function, and slightly lower cognitive-language-motor function. They showed the most increasing trajectory. Profile 4 children (n = 29/35%) had very low cognitive-language-motor function, normal behavioral and auditory nerve function, but showed wide variation in their trajectory. Our preliminary study showed that a multidisciplinary profile-oriented approach may be important in children born VPT to improve counseling and provide targeted treatment for at risk children. High performers at age 2 may not be expected to maintain their favorable development. Behavioral problems might negatively impact language development. Delayed auditory nerve function might represent a slow start and catch-up development.

The effect of prenatal lithium exposure on the neuropsychological development of the child.

OBJECTIVES: Lithium is an effective treatment for bipolar disorder, also during pregnancy to prevent the recurrence of episodes in the perinatal period. Little is known about the neuropsychological development of lithium-exposed offspring. The current study was designed to investigate neuropsychological functioning in lithium-exposed children with the aim to provide further knowledge on the long-term effects of lithium use during pregnancy. METHODS: Participants were offspring of women with a diagnosis of bipolar spectrum disorder, aged 6-14 years. In total, 99 children participated in the study, 56 were exposed to lithium in utero and 43 were not exposed to lithium. Neuropsychological tests were administered, including the Snijders-Oomen Nonverbal Intelligence Test and the NEPSY-II-NL assessment. Linear and negative binomial regression models were used to investigate the association between prenatal lithium exposure and neuropsychological functioning. In secondary analyses, the association between lithium blood level during pregnancy and neuropsychological functioning was assessed. Additionally, norm scores and percentiles for task outcomes were calculated. RESULTS: Lithium use during pregnancy was associated with the total number of mistakes made on the Auditory Attention task, but not statistically significant after full adjustment for potential confounding factors. No association between prenatal lithium exposure and IQ was found. Also, no relationship between lithium blood level during pregnancy and neuropsychological functioning was found after adjustment for potential confounders. Task outcomes in both groups were comparable to the general population. CONCLUSION: In this study, we found no evidence for significantly altered neuropsychological functioning of lithium-exposed children at the age of 6-14 years, when compared to non-lithium-exposed controls.

Contact X-ray Brachytherapy for Older or Inoperable Rectal Cancer Patients: Short-Term Oncological and Functional Follow-Up.

Total mesorectal excision for rectal cancer is a major operation associated with morbidity and mortality. For older or inoperable patients, alternatives are necessary. This prospective study evaluated the oncological and functional outcome and quality of life of older or inoperable rectal cancer patients treated with a contact X-ray brachytherapy boost to avoid major surgery. During follow-up, tumor response and toxicity on endoscopy were scored. Functional outcome and quality of life were assessed with self-administered questionnaires. Additionally, in-depth interviews regarding patients' experiences were conducted. Nineteen patients were included with a median age of 80 years (range 72-91); nine patients achieved a clinical complete response and in another four local control of the tumor was established. The 12 month organ-preservation rate, progression-free survival, and overall survival were 88%, 78%, and 100%, respectively. A transient decrease in quality of life and bowel function was observed at 3 months, which was generally restored at 6 months. In-depth interviews revealed that patients' experience was positive despite the side-effects shortly after treatment. In older or inoperable rectal cancer patients, contact X-ray brachytherapy can be considered an option to avoid total mesorectal excision. Contact X-ray brachytherapy is well-tolerated and can provide good tumor control.

Validity of an early parent-report questionnaire for language disorder in very preterm children from 2 to 10 years of age.

BACKGROUND: Language problems at an early age in very preterm (VP) children can have a detrimental effect on other developmental domains and often persist throughout childhood. The aim of this study was to examine the concurrent and predictive validity of an early language parent-report questionnaire for language disorder in VP children from 2 to 10 years of age. MATERIALS AND METHODS: In 80 VP children (<32 weeks' gestation) without major disabilities, a parent-questionnaire and formal language assessment, both normed for the general population, were administered at 2 years corrected age (CA). Of these infants, 62 were seen for follow-up formal language assessment at age 4 and 61 were seen at age 10. Sensitivity and specificity values were calculated. RESULTS: The Lexi-list showed acceptable concurrent validity for word production scores obtained at age 2 CA. The predictive validity was good for sentence production and acceptable for word production scores obtained at age 4, and low for language production scores obtained at age 10. A Lexi-list cut-off score of <85 (i.e., <-1 SD) was found optimal. INTERPRETATION: A norm-referenced parent-report questionnaire is a useful, first screening tool in a neonatal follow-up. It not only detected early language disorder at age 2 CA but also proved to be a good predictor for language disorder at age 4. However, it did not predict language disorder at age 10. Formal language assessment at age 4 would therefore be recommended for children with an abnormal parent-report language score at age 2 CA.

Glutamate Signaling via the AMPAR Subunit GluR4 Regulates Oligodendrocyte Progenitor Cell Migration in the Developing Spinal Cord.

Oligodendrocyte progenitor cells (OPCs) are specified from discrete precursor populations during gliogenesis and migrate extensively from their origins, ultimately distributing throughout the brain and spinal cord during early development. Subsequently, a subset of OPCs differentiates into mature oligodendrocytes, which myelinate axons. This process is necessary for efficient neuronal signaling and organism survival. Previous studies have identified several factors that influence OPC development, including excitatory glutamatergic synapses that form between neurons and OPCs during myelination. However, little is known about how glutamate signaling affects OPC migration before myelination. In this study, we use in vivo, time-lapse imaging in zebrafish in conjunction with genetic and pharmacological perturbation to investigate OPC migration and myelination when the GluR4A ionotropic glutamate receptor subunit is disrupted. In our studies, we observed that gria4a mutant embryos and larvae displayed abnormal OPC migration and altered dorsoventral distribution in the spinal cord. Genetic mosaic analysis confirmed that these effects were cell-autonomous, and we identified that voltage-gated calcium channels were downstream of glutamate receptor signaling in OPCs and could rescue the migration and myelination defects we observed when glutamate signaling was perturbed. These results offer new insights into the complex system of neuron-OPC interactions and reveal a cell-autonomous role for glutamatergic signaling in OPCs during neural development.SIGNIFICANCE STATEMENT The migration of oligodendrocyte progenitor cells (OPCs) is an essential process during development that leads to uniform oligodendrocyte distribution and sufficient myelination for central nervous system function. Here, we demonstrate that the AMPA receptor (AMPAR) subunit GluR4A is an important driver of OPC migration and myelination in vivo and that activated voltage-gated calcium channels are downstream of glutamate receptor signaling in mediating this migration.

Macroglial diversity: white and grey areas and relevance to remyelination.

Macroglia, comprising astrocytes and oligodendroglial lineage cells, have long been regarded as uniform cell types of the central nervous system (CNS). Although regional morphological differences between these cell types were initially described after their identification a century ago, these differences were largely ignored. Recently, accumulating evidence suggests that macroglial cells form distinct populations throughout the CNS, based on both functional and morphological features. Moreover, with the use of refined techniques including single-cell and single-nucleus RNA sequencing, additional evidence is emerging for regional macroglial heterogeneity at the transcriptional level. In parallel, several studies revealed the existence of regional differences in remyelination capacity between CNS grey and white matter areas, both in experimental models for successful remyelination as well as in the chronic demyelinating disease multiple sclerosis (MS). In this review, we provide an overview of the diversity in oligodendroglial lineage cells and astrocytes from the grey and white matter, as well as their interplay in health and upon demyelination and successful remyelination. In addition, we discuss the implications of regional macroglial diversity for remyelination in light of its failure in MS. Since the etiology of MS remains unknown and only disease-modifying treatments altering the immune response are available for MS, the elucidation of macroglial diversity in grey and white matter and its putative contribution to the observed difference in remyelination efficiency between these regions may open therapeutic avenues aimed at enhancing endogenous remyelination in either area.

Lithium exposure during pregnancy increases fetal growth.

BACKGROUND: Lithium is an effective treatment in pregnancy and postpartum for the prevention of relapse in bipolar disorder, but there is a lack of knowledge about the potential adverse impact on fetal development. AIMS: To investigate the impact of lithium exposure on early fetal growth. METHODS: In this retrospective observational cohort study, we included all singleton pregnancies of women using lithium and referred for advanced fetal ultrasound scanning between 1994 and 2018 to the University Medical Centers in Leiden and Rotterdam, the Netherlands (n=119). The Generation R study, a population-based cohort, served as a non-exposed control population from the same geographic region (n=8184). Fetal head circumference, abdominal circumference, femur length, and transcerebellar diameter were measured by ultrasound at 18-22 weeks of gestation. RESULTS: Lithium use during pregnancy was associated with an average increase in head circumference of 1.77 mm (95% confidence interval: 0.53, 3.01), in abdominal circumference of 5.54 mm (95% confidence interval: 3.95, 7.12) and in femur length of 0.59 mm (95% confidence interval: 0.22, 0.96) at 18-22 weeks gestation. Furthermore, lithium use during pregnancy was associated with an average increase in birth weight of 142.43 grams (95% confidence interval: 58.01, 226.89), whereas it was associated with an average decrease of 1.41 weeks in gestational duration (95% confidence interval: -1.78, -1.05). CONCLUSIONS: Lithium use during pregnancy was associated with increased fetal growth parameters at 18-22 weeks gestational age and increased birth weight. Further research is needed to evaluate both short- and long-term implications, as well as the mechanisms driving this difference in growth.

Impairing committed cholesterol biosynthesis in white matter astrocytes, but not grey matter astrocytes, enhances in vitro myelination.

Remyelination is a regenerative process that is essential to recover saltatory conduction and to prevent neurodegeneration upon demyelination. The formation of new myelin involves the differentiation of oligodendrocyte progenitor cells (OPCs) toward oligodendrocytes and requires high amounts of cholesterol. Astrocytes (ASTRs) modulate remyelination by supplying lipids to oligodendrocytes. Remarkably, remyelination is more efficient in grey matter (GM) than in white matter (WM), which may relate to regional differences in ASTR subtype. Here, we show that a feeding layer of gmASTRs was more supportive to in vitro myelination than a feeding layer of wmASTRs. While conditioned medium from both gmASTRs and wmASTRs accelerated gmOPC differentiation, wmOPC differentiation is enhanced by secreted factors from gmASTRs, but not wmASTRs. In vitro analyses revealed that gmASTRs secreted more cholesterol than wmASTRs. Cholesterol efflux from both ASTR types was reduced upon exposure to pro-inflammatory cytokines, which was mediated via cholesterol transporter ABCA1, but not ABCG1, and correlated with a minor reduction of myelin membrane formation by oligodendrocytes. Surprisingly, a wmASTR knockdown of Fdft1 encoding for squalene synthase (SQS), an enzyme essential for the first committed step in cholesterol biosynthesis, enhanced in vitro myelination. Reduced secretion of interleukin-1ß likely by enhanced isoprenylation, and increased unsaturated fatty acid synthesis, both pathways upstream of SQS, likely masked the effect of reduced levels of ASTR-derived cholesterol. Hence, our findings indicate that gmASTRs export more cholesterol and are more supportive to myelination than wmASTRs, but specific inhibition of cholesterol biosynthesis in ASTRs is beneficial for wmASTR-mediated modulation of myelination.