Sublaminar organization of the human subplate: developmental changes in the distribution of neurons,glia, growing axons and extracellular matrix

The objective of this paper was to collect normative data essential for analyzing the subplate (SP) role in pathogenesis of developmental disorders, characterized by abnormal circuitry, such as hypoxic‐ischemic lesions, autism and schizophrenia. The main cytological features of the SP, such as low cell density, early differentiation of neurons and glia, plexiform arrangement of axons and dendrites, presence of synapses and a large amount of extracellular matrix (ECM) distinguish this compartment from the cell‐dense cortical plate (CP; towards pia) and large fiber bundles of external axonal strata of fetal white matter (towards ventricle). For SP delineation from these adjacent layers based on combined cytological criteria, we analyzed the sublaminar distribution of different microstructural elements and the associated maturational gradients throughout development, using immunocytochemical and histological techniques on postmortem brain material (Zagreb Neuroembryological Collection). The analysis revealed that the SP compartment of the lateral neocortex shows changes in laminar organization throughout fetal development: the monolayer in the early fetal period (presubplate) undergoes dramatic bilaminar transformation between 13 and 15 postconceptional weeks (PCW), followed by subtle sublamination in three ‘floors’ (deep, intermediate, superficial) of midgestation (15–21 PCW). During the stationary phase (22–28 PCW), SP persists as a trilaminar compartment, gradually losing its sublaminar organization towards the end of gestation and remains as a single layer of SP remnant in the newborn brain. Based on these sublaminar transformations, we have documented developmental changes in the distribution, maturational gradients and expression of molecular markers in SP synapses, transitional forms of astroglia, neurons and ECM, which occur concomitantly with the ingrowth of thalamo‐cortical, basal forebrain and cortico‐cortical axons in a deep to superficial fashion. The deep SP is the zone of ingrowing axons – ‘entrance (ingrowth) zone’. The process of axonal ingrowth begins with thalamo‐cortical fibers and basal forebrain afferents, indicating an oblique geometry. During the later fetal period, deep SP receives long cortico‐cortical axons exhibiting a tangential geometry. Intermediate SP (‘proper’) is the navigation and ‘nexus’ sublamina consisting of a plexiform arrangement of cellular elements providing guidance and substrate for axonal growth, and also containing transient connectivity of dendrites and axons in a tangential plane without radial boundaries immersed in an ECM‐rich continuum. Superficial SP is the axonal accumulation (‘waiting compartment’) and target selection zone, indicating a dense distribution of synaptic markers, accumulation of thalamo‐cortical axons (around 20 PCW), overlapping with dendrites from layer VI neurons. In the late preterm brain period, superficial SP contains a chondroitin sulfate non‐immunoreactive band. The developmental dynamics for the distribution of neuronal, glial and ECM markers comply with sequential ingrowth of afferents in three levels of SP: ECM and synaptic markers shift from deep to superficial SP, with transient forms of glia following this arrangement, and calretinin neurons are concentrated in the SP during the formation phase. These results indicate developmental and morphogenetic roles in the SP cellular (transient glia, neurons and synapses) and ECM framework, enabling the spatial accommodation, navigation and establishment of numerous connections of cortical pathways in the expanded human brain. The original findings of early developmental dynamics of transitional subtypes of astroglia, calretinin neurons, ECM and synaptic markers presented in the SP are interesting in the light of recent concepts concerning its functional and morphogenetic role and an increasing interest in SP as a prospective substrate of abnormalities in cortical circuitry, leading to a cognitive deficit in different neurodevelopmental disorders.     

Social inequalities in sleep‐disordered breathing: Evidence from the CoLaus|HypnoLaus study

Sleep‐disordered breathing is a common condition, related to a higher cardiometabolic and neurocognitive risk. The main risk factors for sleep‐disordered breathing include obesity, craniofacial characteristics, male sex and age. However, some studies have suggested that adverse socioeconomic circumstances and lifestyle‐related behaviours such as smoking and alcohol use, may also be risk factors for sleep‐disordered breathing. Here, we investigate the associations between socioeconomic status and sleep‐disordered breathing, as measured by sleep apnea–hypopnea and oxygen desaturation indexes. Furthermore, we assess whether these associations are explained by lifestyle‐related factors (smoking, sedentary behaviour, alcohol use and body mass index [BMI]). We used data from the CoLaus|HypnoLaus study, a population‐based study including 2162 participants from Lausanne (Switzerland). Socioeconomic status was measured through occupation and education. Sleep‐disordered breathing was assessed through polysomnography and measured using the apnea–hypopnea index (AHI: number of apnea/hypopnea events/hr: ≥15/≥30 events), and the ≥3% oxygen desaturation index (ODI: number of oxygen desaturation events/hr: ≥15/≥30 events). Lower occupation and education were associated with higher AHI and ODI (occupation: AHI30, odds ratio (OR) = 1.88, 95% confidence interval (CI) [1.07; 3.31]; ODI30, OR = 2.29, 95% CI [1.19; 4.39]; education: AHI30, OR = 1.21, 95% CI [0.85; 1.72]; ODI30, OR = 1.26, 95% CI [0.83; 1.91]). BMI was associated with socioeconomic status and AHI/ODI, and contributed to the socioeconomic gradient in SDB, with mediation estimates ranging between 43% and 78%. In this Swiss population‐based study, we found that low socioeconomic status is a risk factor for sleep‐disordered breathing, and that these associations are partly explained by BMI. These findings provide a better understanding of the mechanisms underlying social differences in sleep‐disordered breathing and may help implement policies for identifying high‐risk profiles for this disorder.     

Role of positron emission tomography and bone scintigraphy in the evaluation of bone involvement in metastatic pheochromocytoma and paraganglioma: specific implications for succinate dehydrogenase enzyme subunit B gene mutations

We performed a retrospective analysis of 71 subjects with metastatic pheochromocytoma and paraganglioma (30 subjects with mutation of succinate dehydrogenase enzyme subunit B (SDHB) gene and 41 subjects without SDHB mutation). Sixty-nine percent presented with bone metastases (SDHB +/-: 77% vs 63%), 39% with liver metastases (SDHB +/-: 27% vs 47%), and 32% with lung metastases (SDHB +/-: 37% vs 29%). The most common sites of bone involvement were thoracic spine (80%; SDHB+/-: 83% vs 77%), lumbar spine (78%; SDHB +/-: 78% vs 75%), and pelvic and sacral bones (78%; SDHB +/-: 91% vs 65%, P=0.04). Subjects with SDHB mutation also showed significantly higher involvement of long bones (SDHB +/-: 78% vs 30%, P=0.007) than those without the mutation. The best overall sensitivity in detecting bone metastases demonstrated positron emission tomography (PET) with 6-[(18)F]-fluorodopamine ([(18)F]-FDA; 90%), followed by bone scintigraphy (82%), computed tomography or magnetic resonance imaging (CT/MRI; 78%), 2-[(18)F]-fluoro-2-deoxy-d-glucose ([(18)F]-FDG) PET (76%), and scintigraphy with [(123/131)I]-metaiodobenzylguanidine (71%). In subjects with SDHB mutation, imaging modalities with best sensitivities for detecting bone metastases were CT/MRI (96%), bone scintigraphy (95%), and [(18)F]-FDG PET (92%). In subjects without SDHB mutations, the modality with the best sensitivity for bone metastases was [(18)F]-FDA PET (100%). In conclusion, bone scintigraphy should be used in the staging of patients with malignant pheochromocytoma and paraganglioma, particularly in patients with SDHB mutations. As for PET imaging, [(18)F]-FDG PET is highly recommended in SDHB mutation patients, whereas [(18)F]-FDA PET is recommended in patients without the mutation.     

A common polymorphism in the brain-derived neurotrophic factor gene in patients with adult-onset primary focal and segmental dystonia

Brain-derived neurotrophic factor (BDNF) modulates neuroplasticity. A functional polymorphism [Val66Met (G196A)] in BDNF has been reported to modify cortical plasticity in humans. Physiologic investigations have revealed that dystonia might be a consequence of the pathologic plasticity of the sensorimotor cortex. We aimed to investigate the role of the Val66Met polymorphism in a cohort of Serbian patients with adult-onset primary focal and segmental dystonia (PTD). One hundred and forty-nine patients with primary adult-onset PTD, 194 patients with Parkinson’s disease (PD), and 366 healthy control subjects were recruited for the study. Patients with PTD and PD, as well as healthy controls had a similar distribution of genotypes and allele frequencies. There was no any significant difference in the allelic distribution at the Val66Met SNP of the BDNF gene among patients with adult-onset PTD, PD, and healthy volunteers from the same geographic areas. In addition, the presence of the Met allele did not influence the clinical characteristics of PTD patients. Patients with the Met variant did not differ by age at onset, number of affected regions, and efficacy of a sensory trick. Met66Met is not associated with an increased risk of dystonia.     

Brain activation patterns elicited by the 'Faces Symbol Test' -- a pilot fMRI study

The Faces Symbol Test (FST) has recently been proposed as a brief and patient-friendly screening instrument for the assessment of cognitive dysfunction in patients with multiple sclerosis (MS). However, in contrast to well-established MS screening tests such as the Paced Auditory Serial Addition Test, the neural correlates of the FST have not been investigated so far. In the present study, we developed a functional MRI (fMRI) version of the FST to provide first data on brain regions and networks involved in this test. A sample of 19 healthy participants completed a version of the FST adapted for fMRI, requiring matching of faces and symbols in a multiple choice test and two further experimental conditions drawing on cognitive subcomponents (face matching and symbol matching). Imaging data showed a differential involvement of a fronto-parieto-occipital network in the three conditions. The most demanding FST condition elicited brain activation patterns related with sustained attention and executive control. These results suggest that the FST recruits brain networks critical for higher-order cognitive functions often impaired in MS patients.     

Estimation of the enterogastric reflux by modified scintigraphic method

BACKGROUND/AIMS: The aim of the study was to introduce the chosen and modified model of the nuclear medicine method for the detection and quantification of enterogastric reflux, as well as evaluation of its clinical validity. METHODOLOGY: The study was performed in 172 patients: with gastric and duodenal ulcer, after Billroth I and Billroth II gastrectomy, with gastroesophageal reflux, after cholecystectomy, with chronic cholecystitis and chronic duodenal disease. Acquisition was performed with a gamma camera, during 90 min after intravenous application of 185MBq 99mTc-Dietil IDA. Test meal was given in the 30th minute, while the gastric region was marked at the end of the study. On the basis of the radioactivity changes in the regions of the stomach and hepatobiliary system, the presence of enterogastric reflux was determined and its index calculated. RESULTS: In all the groups of patients, values were significantly higher than in the controls (P < 0.05). The most frequent occurrence and the largest quantity of reflux was present in patients after Billroth II gastrectomy with significantly different values from other groups of patients (P < 0.05). CONCLUSIONS: The obtained results approve clinical value of the chosen and modified scintigraphy of enterogastric reflux, as a non-invasive and physiological method, which provides exact data about its presence and quantity.     

Social participation in early and established rheumatoid arthritis patients

Purpose: The aim of the study was to examine whether rheumatoid arthritis (RA) patients with different levels of restriction in social participation differ in disease related as well as psychosocial variables and whether a similar pattern can be found among early and established RA patients.

Method: Two samples of RA patients with early (n?=?97; age?=?53?±?12.3 years; disease duration?= 2.8?±?1.2 years; 76% women) and established (n?=?143; age?=?58?±?10.3 years; disease duration?= 16.1?±?3.6 years; 86% women) were collected. The pattern of differences for the patients with different level of participation restriction (no restriction, mild, moderate or high restriction) was explored by the Jonckheere–Terpstra test. Results: Significant differences were found between patients with different levels of social participation restrictions in both samples in pain, fatigue, functional disability, anxiety, depression and mastery. Generally, it was found that patients with higher restrictions experienced more pain and fatigue, more anxiety and depression and reported lower mastery. Similar pattern of differences concerning disease activity and self-esteem was found mainly in the established group. Conclusions: The study shows that the level of perceived restrictions in social participation are highly relevant regarding the disease related variables such as pain, fatigue and functional disability as well as psychological status and personal resources in both early and established RA.

• Implications for Rehabilitation

• Supporting involvement and participation of individuals with rheumatoid arthritis is important for decreasing the impact of RA symptoms on everyday life.

• Recognition and empowerment of individual resources such a mastery and self-esteem of RA patients could be beneficial for overcoming restrictions in participation.

     

Liver disease and COVID-19: The link with oxidative stress,antioxidants and nutrition

Varying degrees of liver injuries have been reported in patients infected with the severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2). In general, oxidative stress is actively involved in initiation and progression of liver damage. The liver metabolizes various compounds that produce free radicals. Maintaining the oxidative/antioxidative balance is important in coronavirus disease 2019 (COVID-19) patients. Antioxidant vitamins, essential trace elements and food compounds, such as polyphenols, appear to be promising agents, with effects in oxidative burst. Deficiency of these nutrients suppresses immune function and increases susceptibility to COVID-19. Daily micronutrient intake is necessary to support anti-inflammatory and antioxidative effects but for immune function may be higher than current recommended dietary intake. Antioxidant supplements (β-carotene, vitamin A, vitamin C, vitamin E, and selenium) could have a potential role in patients with liver damage. Available evidence suggests that supplementing the diet with a combination of micronutrients may help to optimize immune function and reduce the risk of infection. Clinical trials based on the associations of diet and SARS-CoV-2 infection are lacking. Unfortunately, it is not possible to definitively determine the dose, route of administration and best timing to intervene with antioxidants in COVID-19 patients because clinical trials are still ongoing. Until then, hopefully, this review will enable clinicians to understand the impact of micronutrient dietary intake and liver status assessment in COVID-19 patients.     

A missense mutation in the 3-ketodihydrosphingosine reductase FVT1 as candidate causal mutation for bovine spinal muscular atrophy

The bovine form of the autosomal recessive neurodegenerative disease spinal muscular atrophy (SMA) shows striking similarity to the human form of the disease. It has, however, been mapped to a genomic region not harboring the bovine orthologue of the SMN gene, mutation of which causes human SMA. After refinement of the mapping results we analyzed positional and functional candidate genes. One of three candidate genes, FVT1, encoding 3-ketodihydrosphingosine reductase, which catalyzes a crucial step in the glycosphingolipid metabolism, showed a G-to-A missense mutation that changes Ala-175 to Thr. The identified mutation is limited to SMA-affected animals and carriers and always appears in context of the founder haplotype. The Ala variant found in healthy animals showed the expected 3-ketodihydrosphingosine reductase activity in an in vitro enzyme assay. Importantly, the Thr variant found in SMA animals showed no detectable activity. Surprisingly, in an in vivo assay the mutated gene complements the growth defect of a homologous yeast knockout strain as well as the healthy variant. This finding explains the viability of affected newborn calves and the later neuron-specific onset of the disease, which might be due to the high sensitivity of these neurons to changes in housekeeping functions. Taken together, the described mutation in FVT1 is a strong candidate for causality of SMA in cattle. This result provides an animal model for understanding the underlying mechanisms of the development of SMA and will allow efficient selection against the disease in cattle.     

Kinetics of gene expression in murine cutaneous graft-versus-host disease

The kinetics of gene expression associated with the development of cutaneous graft-versus-host disease (GVHD) were examined in a mouse model of MHC-matched allogeneic hematopoietic stem cell transplantation. Ear skin was obtained from recipient mice with or without GVHD between 7 and 40 days after transplantation for histopathological analysis and gene expression profiling. Gene expression patterns were consistent with early infiltration and activation of CD8(+) T and mast cells, followed by CD4(+) T, natural killer, and myeloid cells. The sequential infiltration and activation of effector cells correlated with the histopathological development of cutaneous GVHD and was accompanied by up-regulated expression of many chemokines and their receptors (CXCL-1, -2, -9, and -10; CCL-2, -5, -6, -7, -8, -9, -11, and -19; CCR-1 and CCR-5), adhesion molecules (ICAM-1, CD18, Ly69, PSGL-1, VCAM-1), molecules involved in antigen processing and presentation (TAP1 and TAP2, MHC class I and II, CD80), regulators of apoptosis (granzyme B, caspase 7, Bak1, Bax, and BclII), interferon-inducible genes (STAT1, IRF-1, IIGP, GTPI, IGTP, Ifi202A), stimulators of fibroblast proliferation and matrix synthesis (interleukin-1beta, transforming growth factor-beta1), and markers of keratinocyte proliferation (keratins 5 and 6), and differentiation (small proline-rich proteins 2E and 1B). Many acute-phase proteins were up-regulated early in murine cutaneous GVHD including serum amyloid A2 (SAA2), SAA3, serpins a3g and a3n, secretory leukocyte protease inhibitor, and metallothioneins 1 and 2. The kinetics of gene expression were consistent with the evolution of cutaneous pathology as well as with current models of disease progression during cutaneous GVHD.