HIV and COVID-19: two pandemics with significant (but different) central nervous system complications.

Human immunodeficiency virus (HIV) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) cause significant neurologic disease. Central nervous system (CNS) involvement of HIV has been extensively studied, with well-documented invasion of HIV into the brain in the initial stage of infection, while the acute effects of SARS-CoV-2 in the brain are unclear. Neuropathologic features of active HIV infection in the brain are well characterized whereas neuropathologic findings in acute COVID-19 are largely non-specific. On the other hand, neuropathologic substrates of chronic dysfunction in both infections, as HIV-associated neurocognitive disorders (HAND) and post-COVID conditions (PCC)/long COVID are unknown. Thus far, neuropathologic studies on patients with HAND in the era of combined antiretroviral therapy have been inconclusive, and autopsy studies on patients diagnosed with PCC have yet to be published. Further longitudinal, multidisciplinary studies on patients with HAND and PCC and neuropathologic studies in comparison to controls are warranted to help elucidate the mechanisms of CNS dysfunction in both conditions.

Low-grade B-cell lymphoma of the central nervous system with plasmacytic differentiation and amyloid deposition.

A 65-year-old woman with a resolved history of epilepsy due to a motor vehicle accident and hippocampal sclerosis presented with recurrent de novo seizures. Brain imaging demonstrated enhancement in the left parieto-occipital lobe. At histopathological examination, the lesion displayed a diffuse lymphoid infiltrate comprised of small atypical lymphocytes, plasmacytoid lymphocytes, and scattered plasma cells with amyloid deposition. Pathology workup demonstrated a monotypic B-cell phenotype of the lymphoid infiltrate, expressing lambda light chain restriction and plasmacytic differentiation without MYD88 mutations. The patient had no systemic evidence of lymphoma, plasma cell dyscrasia, or amyloidosis. A diagnosis of low-grade B-cell lymphoma of the central nervous system with plasmacytic differentiation and amyloid deposition was made.

A 62-Year-Old Woman With Nodules, Cysts, and Activated Bone Marrow.

CASE PRESENTATION: A 62-year-old woman with a long-term smoking history was evaluated at our lung cancer clinic for a new 2.5-cm lung nodule. She had a history of well-controlled COPD and hypertension. She was in overall good health until 3 weeks before her evaluation in an ED for new-onset exertional dyspnea. Her physical examination was unremarkable, except for diffuse hyperpigmented scaly scalp lesions that coalesced into plaques. Her subjective symptoms were nonproductive cough, exertional dyspnea, unintentional weight loss of 10 lb, and fatigue that had started 2 months earlier. She did not have fever or night sweats.

Engineering of TeO2-ZnO-BaO-Based Glasses for Mid-Infrared Transmitting Optics.

In this paper, the glass systems, TeO2-ZnO-BaO (TZB), TeO2-ZnO-BaO-Nb2O5 (TZB-Nb) and TeO2-ZnO-BaO-MoO3 (TZB-Mo), were fabricated by the traditional melt-quench protocol for use as mid-infrared (mid-IR) transmitting optical material. The effect of Nb2O5 and MoO3 on the key glass material properties was studied through various techniques. From the Raman analysis, it was found that the structural modification was clear with the addition of both Nb2O5 and MoO3 in the TZB system. The transmittance of studied glasses was measured and found that the optical window covered a region from 0.4 to 6 µm. The larger linear refractive index was obtained for the Nb2O5-doped TZB glass system than that of other studied systems. High glass transition temperature, low thermo-mechanical coefficient and high Knoop hardness were noticed in the Nb2O5-doped TZB glass system due to the increase in cross-linking density and rigidity in the tellurite network. The results suggest that the Nb2O5-doped TZB optical glasses could be a promising material for mid-infrared transmitting optics.

Endoscopic Management of Ganglioneuroma in the Stomach.

Ganglioneuromas are rare benign tumors of neuroblastic origin that can occur anywhere along the sympathetic chain. They are rarely found in the gastrointestinal tract and can appear as solitary polypoid lesions or diffuse as part of a familial syndrome. They are often asymptomatic but may present with nonspecific symptoms depending on their anatomic location. They have no special endoscopic appearance and are diagnosed by histology and immunohistochemistry staining. We present a case of solitary gastric ganglioneuroma treated successfully with endoscopic resection.

A complete inorganic colour converter based on quantum-dot-embedded silicate glasses for white light-emitting-diodes.

A complete inorganic quantum dot color converter for a white LED is achieved using silicate-based quantum-dot-embedded glasses (QDEGs). The white LED exhibits a high CRI of 90 and highly improved thermal stability up to 200 °C, demonstrating its robustness and practicality. The CdSe/CdS core/shell structure within the silicate glass is expected to enhance the colour converting efficiency.

Genomic DISC1 Disruption in hiPSCs Alters Wnt Signaling and Neural Cell Fate.

Genetic and clinical association studies have identified disrupted in schizophrenia 1 (DISC1) as a candidate risk gene for major mental illness. DISC1 is interrupted by a balanced chr(1;11) translocation in a Scottish family in which the translocation predisposes to psychiatric disorders. We investigate the consequences of DISC1 interruption in human neural cells using TALENs or CRISPR-Cas9 to target the DISC1 locus. We show that disruption of DISC1 near the site of the translocation results in decreased DISC1 protein levels because of nonsense-mediated decay of long splice variants. This results in an increased level of canonical Wnt signaling in neural progenitor cells and altered expression of fate markers such as Foxg1 and Tbr2. These gene expression changes are rescued by antagonizing Wnt signaling in a critical developmental window, supporting the hypothesis that DISC1-dependent suppression of basal Wnt signaling influences the distribution of cell types generated during cortical development.

Mechanosensitivity of fibroblast cell shape and movement to anisotropic substratum topography gradients.

In this report, we describe using ultraviolet (UV)-assisted capillary force lithography (CFL) to create a model substratum of anisotropic micro- and nanotopographic pattern arrays with variable local density for the analysis of cell-substratum interactions. A single cell adhesion substratum with the constant ridge width (1 microm), and depth (400 nm) and variable groove widths (1-9.1 microm) allowed us to characterize the dependence of cellular responses, including cell shape, orientation, and migration, on the anisotropy and local density of the variable micro- and nanotopographic pattern. We found that fibroblasts adhering to the denser pattern areas aligned and elongated more strongly along the direction of ridges, vs. those on the sparser areas, exhibiting a biphasic dependence of the migration speed on the pattern density. In addition, cells responded to local variations in topography by altering morphology and migrating along the direction of grooves biased by the direction of pattern orientation (short term) and pattern density (long term), suggesting that single cells can sense the topography gradient. Molecular dynamic live cell imaging and immunocytochemical analysis of focal adhesions and actin cytoskeleton suggest that variable substratum topography can result in distinct types of cytoskeleton reorganization. We also demonstrate that fibroblasts cultured as monolayers on the same substratum retain most of the properties displayed by single cells. This result, in addition to demonstrating a more sophisticated method to study aspects of wound healing processes, strongly suggests that even in the presence of adhesive cell-cell interactions, the cues provided by the underlying substratum topography continue to exercise substantial influence on cell behavior. The described experimental platform might not only further our understanding of biomechanical regulation of cell-matrix interactions, but also contribute to bioengineering of devices with the optimally structured design of cell-material interface.

Guided Cell Migration on Microtextured Substrates with Variable Local Density and Anisotropy.

This work reports the design of and experimentation with a topographically patterned cell culture substrate of variable local density and anisotropy as a facile and efficient platform to guide the organization and migration of cells in spatially desirable patterns. Using UV-assisted capillary force lithography, an optically transparent microstructured layer of a UV curable poly(urethane acrylate) resin is fabricated and employed as a cell-culture substrate after coating with fibronectin. With variable local pattern density and anisotropy present in a single cell-culture substrate, the differential polarization of cell morphology and movement in a single experiment is quantitatively characterized. It is found that cell shape and velocity are exquisitely sensitive to variation in the local anisotropy of the two-dimensional rectangular lattice arrays, with cell elongation and speed decreasing on symmetric lattice patterns. It is also found that cells could integrate orthogonal spatial cues when determining the direction of cell orientation and movement. Furthermore, cells preferentially migrate toward the topographically denser areas from sparser ones. Consistent with these results, it is demonstrated that systematic variation of local densities of rectangular lattice arrays enable a planar assembly of cells into a specified location. It is envisioned that lithographically defined substrates of variable local density and anisotropy not only provide a new route to tailoring the cell-material interface but could serve as a template for advanced tissue engineering.