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Anatomical Record (Hoboken, N.J. : 2007) Jun 2024The existence of a previously unrecognized subarachnoid lymphatic-like membrane (SLYM) was reported in a recent study. SLYM is described as an intermediate... (Review)
Review
The existence of a previously unrecognized subarachnoid lymphatic-like membrane (SLYM) was reported in a recent study. SLYM is described as an intermediate leptomeningeal layer between the arachnoid and pia mater in mouse and human brains, which divides the subarachnoid space (SAS) into two functional compartments. Being a macroscopic structure, having missed detection in previous studies is surprising. We systematically reviewed the published reports in animals and humans to explore whether prior descriptions of this meningeal layer were reported in some way. A comprehensive search was conducted in PubMed/Medline, EMBASE, Google Scholar, Science Direct, and Web of Science databases using combinations of MeSH terms and keywords with Boolean operators from inception until 31 December 2023. We found at least eight studies that provided structural evidence of an intermediate leptomeningeal layer in the brain or spinal cord. However, unequivocal descriptions for this layer all along the central nervous system were scarce. Obscure names like the epipial, intermediate meningeal, outer pial layers, or intermediate lamella were used to describe it. Its microscopic/ultrastructural details closely resemble the recently reported SLYM. We further examined the counterarguments in current literature that are skeptical of the existence of this layer. The potential physiological and clinical implications of this new meningeal layer are significant, underscoring the urgent need for further exploration of its structural and functional details.
PubMed: 38924700
DOI: 10.1002/ar.25524 -
Journal of Biomedical Materials... Oct 2023The fabrication of biodegradable, bioabsorbable, and biocompatible vascular scaffolds with enhanced mechanical and biological properties that are able to modulate local...
The fabrication of biodegradable, bioabsorbable, and biocompatible vascular scaffolds with enhanced mechanical and biological properties that are able to modulate local inflammation and induce endothelialization after surgical implant is still a challenge. In this work, a fibrous scaffold, made of poly(ε-caprolactone) and poly(glycerol sebacate), was fabricated to be potentially used as a small-diameter graft in vascular surgery. The novelty of this research is represented by the direct incorporation of quercetin, a well-known antioxidant compound with several biological properties, into a polymeric scaffold obtaining a vascular construct able to modulate two key factors involved in postsurgical inflammation, matrix metalloproteinase-9 and endothelial nitric oxide synthase. For its production, an electrospinning apparatus, a solution made of the two polymers (both 20% (w/v), mixed at the ratio 1:1 (v/v)), and free quercetin (0.05% (w/v)) were used. Scanning electron and atomic force microscopies were employed to investigate the morphological properties of the fabricated electrospun scaffolds. Furthermore, physicochemical properties, including Fourier-transform infrared spectroscopy, mass loss, fluid uptake, quercetin release, mechanical properties, and biological activity of the scaffolds were studied. The expression of matrix metalloproteinase-9, tissue inhibitor of metalloproteinase-1, and of endothelial nitric oxide synthase was evaluated when the quercetin-functionalized scaffold was exposed to human endothelial cells treated with tumor necrosis factor-α. The results of this study confirmed the feasibility of incorporating free quercetin during the electrospinning process to impart biological properties to small-diameter vascular prostheses.
Topics: Blood Vessel Prosthesis; Humans; Cell Line; Cell Survival; Biocompatible Materials; Quercetin
PubMed: 37128974
DOI: 10.1002/jbm.a.37535 -
Molecular Neurobiology Mar 2024Subarachnoid hemorrhage (SAH) is a neurological emergency that can lead to fatal outcomes. It occurs when bleeding happens in the subarachnoid space, a small gap between...
Causal Relationships Between Gut Microbiota, Inflammatory Cells/Proteins, and Subarachnoid Hemorrhage: A Multi-omics Bidirectional Mendelian Randomization Study and Meta-analysis.
Subarachnoid hemorrhage (SAH) is a neurological emergency that can lead to fatal outcomes. It occurs when bleeding happens in the subarachnoid space, a small gap between the arachnoid and pia mater. This condition results from the rupture of diseased or damaged blood vessels at the brain's base or surface. This study combined various omics approaches with Mendelian randomization analysis, including MR-IVW, MR Egger, MR weight median, and MR weight mode, to generate preliminary results. It also employed reverse Mendelian randomization, treating SAH as the exposure. Finally, a meta-analysis was conducted to summarize these findings. The study found positive correlations between SAH and both GBPA-Pyridoxal 5 phosphate biosynthesis I (OR=1.48, 95% CI, 1.04-2.12) and GBPA-glucose biosynthesis I (OR=0.68, 95% CI, 0.52-0.90). Increased levels of urokinase-type plasma activator were also associated with SAH (OR=1.17, 95% CI, 1.04-1.32). Associations were observed with SAH for CD80 on CD62L+ plasmacytoid dendritic cells, CD80 on plasmacytoid dendritic cells, CD123 on CD62L+ plasmacytoid dendritic cells, and SSC-A on plasmacytoid dendritic cells. This study, through Mendelian randomization and meta-analysis, established links between SAH and four inflammatory cells, one inflammatory protein, and two gut microbiota-related pathways. These findings suggest potential treatment targets for SAH, highlighting the importance of modulating gut microbiota and utilizing anti-inflammatory drugs in its management.
PubMed: 38523223
DOI: 10.1007/s12035-024-04101-y -
Frontiers in Neurology 2023Relapsing polychondritis (RP) is a rare rheumatologic disorder that may affect the neurological system with various presentations. In this study, we present a case and...
BACKGROUND AND PURPOSE
Relapsing polychondritis (RP) is a rare rheumatologic disorder that may affect the neurological system with various presentations. In this study, we present a case and summarize the clinical characteristics of RP-associated meningoencephalitis.
CASE PRESENTATION
A 48-year-old man presented with first-ever seizures that were well controlled by valproate. Physical examination results were unremarkable, except for binaural deformation. The initial brain magnetic resonance imaging (MRI) without contrast and electroencephalogram (EEG) findings were normal. However, the patient subsequently developed recurrent fever, scleritis, headache, lethargy, and left arm paresis. Repeated brain MRI with contrast demonstrated increased enhancement of the pia mater and abnormal diffusion-weighted imaging (DWI) signals in the bilateral auricles. The cerebrospinal fluid (CSF) analysis showed 2 leukocytes/μL, 736.5 mg/L of protein, and no evidence of infectious disease or autoimmune encephalitis. Meningoencephalitis secondary to RP was considered. The patient's condition improved significantly and quickly with the administration of dexamethasone (10 mg per day). Oral methylprednisolone was continued, and the patient remained well without relapse during the 9-month follow-up period.
CONCLUSION
RP-associated meningoencephalitis is rare but fatal. Although symptoms vary, red or deformed ears remain the most common and suggestive features. Non-specific parenchymal changes and/or meningeal enhancement can be observed on brain MRI scans. CSF lymphocytic pleocytosis with mild protein elevation was observed in most patients.
PubMed: 38033767
DOI: 10.3389/fneur.2023.1265345 -
International Journal of Surgery Case... Aug 2023Spinal tumors constitute 15 % of all tumors in the central nervous system. Pain is often the initial symptom, which can be localized, nocturnal, or radiated to the arms...
INTRODUCTION
Spinal tumors constitute 15 % of all tumors in the central nervous system. Pain is often the initial symptom, which can be localized, nocturnal, or radiated to the arms and/or limbs. We report a rare case with a subpial lipoma in the cervicothoracic spine and review the current literature.
CASE PRESENTATION
A 22-year-old female presented with the chief complaint of tetraparesis for three months before admission. Magnetic resonance imaging revealed an intradural tumor on the fifth cervical to fourth thoracic vertebrae. She underwent a laminectomy to remove the tumor completely. Histopathological examination revealed a proliferation of mature fat cells amongst fibrous connective tissue. Surrounding nerve fibers and erythrocyte-filled blood vessels were also found, suggesting a subpial fibrolipoma. Postoperatively, there was an improvement in muscle strength six weeks after surgery. Motoric strength was grade 5 for the upper extremities and grade 4 for the lower extremities.
DISCUSSION
In this patient, cervicothoracic laminectomy and tumor removal were performed without instrumentation. Total tumor resection is the primary goal when removing a pathological lesion. However, this depends on the lesion's adhesion to the surrounding tissue. Therefore, partial tumor resection may be possible, given the neurological complications that can occur.
CONCLUSION
Because subpial lipomas are rare, their treatment is highly specialized. An assessment of the patient's physical condition and imaging assessments can provide information about potential treatment strategies and outcomes.
PubMed: 37544094
DOI: 10.1016/j.ijscr.2023.108616 -
ACS Applied Materials & Interfaces Jan 2024Charge-transfer (CT) interactions between co-facially aligned π-donor/acceptor (π-D/A) arrays engender unique optical and electronic properties that could benefit...
Charge-transfer (CT) interactions between co-facially aligned π-donor/acceptor (π-D/A) arrays engender unique optical and electronic properties that could benefit (supra)molecular electronics and energy technologies. Herein, we demonstrate that a tetragonal prismatic metal-organic cage (MOC1) having two parallel π-donor tetrakis(4-carboxyphenyl)-Zn-porphyrin (ZnTCPP) faces selectively intercalate planar π-acceptor guests, such as hexaazatriphenylene hexacarbonitrile (HATHCN), hexacyanotriphenylene (HCTP), and napthanelediimide (NDI) derivatives, forming 1:1 πA@MOC1 inclusion complexes featuring supramolecular π-D/A/D triads. The π-acidity of intercalated π-acceptors (HATHCN ≫ HCTP ≈ NDIs) dictated the nature and strength of their interactions with the ZnTCPP faces, which in turn influenced the binding affinities () and optical and electronic properties of corresponding πA@MOC1 inclusion complexes. Owing to its strongest CT interaction with ZnTCPP faces, the most π-acidic HATHCN guest enjoyed the largest (5 × 10 M), competitively displaced weaker π-acceptors from the MOC1 cavity, and generated the highest electrical conductivity (2.1 × 10 S/m) among the πA@MOC1 inclusion complexes. This work demonstrates a unique through-space charge transport capability of πA@MOC1 inclusion complexes featuring supramolecular π-D/A/D triads, which generated tunable electrical conductivity, which is a rare but much coveted electronic property of such supramolecular assemblies that could further expand their utility in future technologies.
PubMed: 38108279
DOI: 10.1021/acsami.3c15959 -
Child's Nervous System : ChNS :... Nov 2023Retethering is not an unusual operation for a congenital lumbosacral dysraphic spinal lesion. The present study aimed to assess a new surgical technique for preventing...
OBJECTIVE
Retethering is not an unusual operation for a congenital lumbosacral dysraphic spinal lesion. The present study aimed to assess a new surgical technique for preventing retethering.
SURGICAL TECHNIQUE
After untethering the spinal cord, the pia mater or scar tissue at the caudal end of the conus medullaris is anchored to the ventral dura mater loosely using 8-0 thread, and the dura mater is closed directly. This technique is called ventral anchoring.
RESULTS
Ventral anchoring was performed in 15 patients (aged 5 to 37 years old, average age: 12.1 years old) between 2014 and 2021. All but one patient showed improvement or stabilization of the preoperative symptoms. No complication directly related to the procedure was observed. Postoperative MRI demonstrated that the dorsal subarachnoid space was restored in 14 patients but was undetectable or absent in three patients on follow-up MRI. No patients have experienced a recurrence of the tethered cord syndrome during the follow-up period.
CONCLUSION
Ventral anchoring is effective for restoring the dorsal subarachnoid space after untethering the spinal cord. This preliminary study suggested that ventral anchoring has the potential to prevent the postoperative radiographic recurrence of tethered spinal cord in patients with a congenital lumbosacral dysraphic spinal lesion.
Topics: Humans; Child; Child, Preschool; Adolescent; Young Adult; Adult; Spinal Cord; Neural Tube Defects; Magnetic Resonance Imaging
PubMed: 37115276
DOI: 10.1007/s00381-023-05972-7 -
ACS Applied Electronic Materials Sep 2023Printed circuit boards (PCBs) physically support and connect electronic components to the implementation of complex circuits. The most widespread insulating substrate...
Printed circuit boards (PCBs) physically support and connect electronic components to the implementation of complex circuits. The most widespread insulating substrate that also acts as a mechanical support in PCBs is commercially known as FR4, and it is a glass-fiber-reinforced epoxy resin laminate. FR4 has exceptional dielectric, mechanical, and thermal properties. However, it was designed without considering sustainability and end-of-life aspects, heavily contributing to the accumulation of electronic waste in the environment. Thus, greener alternatives that can be reprocessed, reused, biodegraded, or composted at the end of their function are needed. This work presents the development and characterization of a PCB substrate based on poly(lactic acid) and cotton fabric, a compostable alternative to the conventional FR4. The substrate has been developed by compression molding, a process compatible with the polymer industry. We demonstrate that conductive silver ink can be additively printed on the substrate's surface, as its morphology and wettability are similar to those of FR4. For example, the compostable PCB's water contact angle is 72°, close to FR4's contact angle of 64°. The developed substrate can be thermoformed to curved surfaces at low temperatures while preserving the conductivity of the silver tracks. The green substrate has a dielectric constant comparable to that of the standard FR4, showing a value of 5.6 and 4.6 at 10 and 100 kHz, respectively, which is close to the constant value of 4.6 of FR4. The substrate is suitable for microdrilling, a fundamental process for integrating electronic components to the PCB. We implemented a proof-of-principle circuit to control the blinking of LEDs on top of the PCB, comprising resistors, capacitors, LEDs, and a dual in-line package circuit timer. The developed PCB substrate represents a sustainable alternative to standard FR4 and could contribute to the reduction of the overwhelming load of electronic waste in landfills.
PubMed: 37779887
DOI: 10.1021/acsaelm.3c00799 -
DNA Damage and Senescence in the Aging and Alzheimer's Disease Cortex Are Not Uniformly Distributed.Biomedicines Jun 2024Alzheimer's disease (AD) is a neurodegenerative illness with a typical age of onset exceeding 65 years of age. The age dependency of the condition led us to track the...
Alzheimer's disease (AD) is a neurodegenerative illness with a typical age of onset exceeding 65 years of age. The age dependency of the condition led us to track the appearance of DNA damage in the frontal cortex of individuals who died with a diagnosis of AD. The focus on DNA damage was motivated by evidence that increasing levels of irreparable DNA damage are a major driver of the aging process. The connection between aging and the loss of genomic integrity is compelling because DNA damage has also been identified as a possible cause of cellular senescence. The number of senescent cells has been reported to increase with age, and their senescence-associated secreted products are likely contributing factors to age-related illnesses. We tracked DNA damage with 53BP1 and cellular senescence with p16 immunostaining of human post-mortem brain samples. We found that DNA damage was significantly increased in the BA9 region of the AD cortex compared with the same region in unaffected controls (UCs). In the AD but not UC cases, the density of cells with DNA damage increased with distance from the pia mater up to approximately layer V and then decreased in deeper areas. This pattern of DNA damage was overlaid with the pattern of cellular senescence, which also increased with cortical depth. On a cell-by-cell basis, we found that the intensities of the two markers were tightly linked in the AD but not the UC brain. To test whether DNA damage was a causal factor in the emergence of the senescence program, we used etoposide treatment to damage the DNA of cultured mouse primary neurons. While DNA damage increased after treatment, after 24 h, no change in the expression of senescence-associated markers was observed. Our work suggests that DNA damage and cellular senescence are both increased in the AD brain and increasingly coupled. We propose that in vivo, the relationship between the two age-related processes is more complex than previously thought.
PubMed: 38927534
DOI: 10.3390/biomedicines12061327 -
Acta Neurochirurgica Jul 2023The cerebellopontine angle (CPA) is a frequent region of skull base pathologies and therefore a target for neurosurgical operations. The outer arachnoid is the key...
PURPOSE
The cerebellopontine angle (CPA) is a frequent region of skull base pathologies and therefore a target for neurosurgical operations. The outer arachnoid is the key structure to approach the here located lesions. The goal of our study was to describe the microsurgical anatomy of the outer arachnoid of the CPA and its pathoanatomy in case of space-occupying lesions.
METHODS
Our examinations were performed on 35 fresh human cadaveric specimens. Macroscopic dissections and microsurgical and endoscopic examinations were performed. Retrospective analysis of the video documentations of 35 CPA operations was performed to describe the pathoanatomical behavior of the outer arachnoid.
RESULTS
The outer arachnoid cover is loosely attached to the inner surface of the dura of the CPA. At the petrosal surface of the cerebellum the pia mater is strongly adhered to the outer arachnoid. At the level of the dural penetration of the cranial nerves, the outer arachnoid forms sheath-like structures around the nerves. In the midline, the outer arachnoid became detached from the pial surface and forms the base of the posterior fossa cisterns. In pathological cases, the outer arachnoid became displaced. The way of displacement depends on the origin of the lesion. The most characteristic patterns of changes of the outer arachnoid were described in case of meningiomas, vestibular schwannomas, and epidermoid cysts of the CPA.
CONCLUSION
The knowledge of the anatomy of the outer arachnoid of the cerebellopontine region is essential to safely perform microsurgical approaches as well as of dissections during resection of pathological lesions.
Topics: Humans; Cerebellopontine Angle; Retrospective Studies; Magnetic Resonance Imaging; Arachnoid; Meningeal Neoplasms; Cadaver
PubMed: 37133788
DOI: 10.1007/s00701-023-05601-x