Complex IV subunit isoform COX6A2 protects fast-spiking interneurons from oxidative stress and supports their function.

Parvalbumin-positive (PV+ ) fast-spiking interneurons are essential to control the firing activity of principal neuron ensembles, thereby regulating cognitive processes. The high firing frequency activity of PV+ interneurons imposes high-energy demands on their metabolism that must be supplied by distinctive machinery for energy generation. Exploring single-cell transcriptomic data for the mouse cortex, we identified a metabolism-associated gene with highly restricted expression to PV+ interneurons: Cox6a2, which codes for an isoform of a cytochrome c oxidase subunit. Cox6a2 deletion in mice disrupts perineuronal nets and enhances oxidative stress in PV+ interneurons, which in turn impairs the maturation of their morphological and functional properties. Such dramatic effects were likely due to an essential role of COX6A2 in energy balance of PV+ interneurons, underscored by a decrease in the ATP-to-ADP ratio in Cox6a2-/- PV+ interneurons. Energy disbalance and aberrant maturation likely hinder the integration of PV+ interneurons into cortical neuronal circuits, leading to behavioral alterations in mice. Additionally, in a human patient bearing mutations in COX6A2, we found a potential association of the mutations with mental/neurological abnormalities.

Foam-Based Drug Delivery: A Newer Approach for Pharmaceutical Dosage Form.

Foam is a dispersal of gas in solid foam or liquid foam. Solid foams are generally formed through quick curing of liquid foams. Because of their positive characteristics, simplicity of application, and improved patient acceptability/compliance, foams are an appealing and promising delivery strategy for medical, cosmetic, and pharmaceutical, applications. Recent breakthroughs in topical foams for cosmetic and dermal applications are described here, as well as categorization based on foam formulation and recent assessment techniques of critical physical properties of the topical foam. Despite the expanding amount of knowledge on topical foams for cutaneous applications, the majority of research has focused on the stability and structure of foam in contact with solid nonporous surfaces. It is still difficult to figure out how such foams destabilize when they come into touch with porous surfaces like skin or skin-like membranes. The foam-covered wide surface area and easily applied to the affected area. This type of delivery system also eliminates the chance of secondary infection that is associated with ointment and creams, which need to be applied to the affected area with help of fingers or an applicator.

Rapid prototyping technology for cranioplasty: A case series.

Cranial vault defects may be acquired or congenital in origin. Rehabilitation of these patients often poses challenge to the operating team and prosthodontist. Polymethylmethacrylate is a commonly used alloplastic graft material which is used for the fabrication of cranial prosthesis. Nowadays, with the advancement in the bioengineering, custom-made template and cranial prosthesis can be made by rapid prototyping technology (RPT) by patient three-dimensional (3D) computed tomography (CT) scan images. This series of two cases explained two different techniques for the rehabilitation of the patient with frontotemporoparietal cranial defect. Case 1 had a history of cerebrovascular accident, followed by decompression craniotomy which led to frontotemporoparietal defect of the left side. This defect area was associated with the cerebrospinal fluid accumulation which made delineation of underlying bony margins difficult and interfered with conventional impression procedures. Case 2 had a road traffic accident which led to intracerebral hemorrhage followed by decompression craniotomy which resulted in frontotemporoparietal defect of the right side. The patient had a poor neuromuscular control which impedes with the upright posture of the head during impression making of the defect area. Therefore, these cases were planned to rehabilitate by RPT. In these techniques, the prosthesis was made using custom-made skull template produced by RPT, using the data of 3D-CT scan images. This technique resulted in the prosthesis with good esthetics and better fit of the prosthesis. The contours of the prosthesis were replicated in the same manner as compared to the contralateral side. RPT is an additive manufacturing technology which is now used in the field of dentistry too. This technique is easy to use; fabricate prosthesis with high precision is less time-consuming and has fewer chances of error.

Advances in nickel-catalyzed cycloaddition reactions to construct carbocycles and heterocycles.

Transition-metal catalysis has revolutionized the field of organic synthesis by facilitating the construction of complex organic molecules in a highly efficient manner. Although these catalysts are typically based on precious metals, researchers have made great strides in discovering new base metal catalysts over the past decade. This Account describes our efforts in this area and details the development of versatile Ni complexes that catalyze a variety of cycloaddition reactions to afford interesting carbocycles and heterocycles. First, we describe our early work in investigating the efficacy of N-heterocyclic carbene (NHC) ligands in Ni-catalyzed cycloaddition reactions with carbon dioxide and isocyanate. The use of sterically hindered, electron donating NHC ligands in these reactions significantly improved the substrate scope as well as reaction conditions in the syntheses of a variety of pyrones and pyridones. The high reactivity and versatility of these unique Ni(NHC) catalytic systems allowed us to develop unprecedented Ni-catalyzed cycloadditions that were unexplored due to the inefficacy of early Ni catalysts to promote hetero-oxidative coupling steps. We describe the development and mechanistic analysis of Ni/NHC catalysts that couple diynes and nitriles to form pyridines. Kinetic studies and stoichiometric reactions confirmed a hetero-oxidative coupling pathway associated with this Ni-catalyzed cycloaddition. We then describe a series of new substrates for Ni-catalyzed cycloaddition reactions such as vinylcyclopropanes, aldehydes, ketones, tropones, 3-azetidinones, and 3-oxetanones. In reactions with vinycyclopropanes and tropones, DFT calculations reveal noteworthy mechanistic steps such as a C-C σ-bond activation and an 8π-insertion of vinylcyclopropane and tropone, respectively. Similarly, the cycloaddition of 3-azetidinones and 3-oxetanones also requires Ni-catalyzed C-C σ-bond activation to form N- and O-containing heterocycles.

An in Situ Approach to Nickel-Catalyzed Cycloaddition of Alkynes and 3-Azetidinones.

An efficient and convenient procedure that generates the active Ni(0) catalyst in situ from cheap, air stable Ni(II) precursors is developed for the [4 + 2]-cycloaddition of alkynes and 3-azetidinones. The reaction affords useful 3-dehydropiperidinones in comparable yields to the reported Ni(0) procedure. Additionally, the cycloaddition with 3-oxetanone afforded the 3-dehydropyranone product. Chiral 2-substituted azetidinones were also tolerated to form substituted dehydropiperidinones in high yield and enantiomeric excess.

Ni(NHC)]-catalyzed cycloaddition of diynes and tropone: apparent enone cycloaddition involving an 8π insertion.

A Ni/N-heterocyclic carbene catalyst couples diynes to the C(α)-C(ß) double bond of tropone, a type of reaction that is unprecedented for metal-catalyzed cycloadditions with aromatic tropone. Many different diynes were efficiently coupled to afford [5-6-7] fused tricyclic products, while [5-7-6] fused tricyclic compounds were obtained as minor byproducts in a few cases. The reaction has broad substrate scope and tolerates a wide range of functional groups, and excellent regioselectivity is found with unsymmetrical diynes. Theoretical calculations show that the apparent enone cycloaddition occurs through a distinctive 8π insertion of tropone. The initial intramolecular oxidative cyclization of diyne produces the nickelacyclopentadiene intermediate. This intermediate undergoes an 8π insertion of tropone, and subsequent reductive elimination generates the [5-6-7] fused tricyclic product. This initial product undergoes two competing isomerizations, leading to the observed [5-6-7] and [5-7-6] fused tricyclic products.

HYENA detects oncogenes activated by distal enhancers in cancer.

Somatic structural variations (SVs) in cancer can shuffle DNA content in the genome, relocate regulatory elements, and alter genome organization. Enhancer hijacking occurs when SVs relocate distal enhancers to activate proto-oncogenes. However, most enhancer hijacking studies have only focused on protein-coding genes. Here, we develop a computational algorithm "HYENA" to identify candidate oncogenes (both protein-coding and non-coding) activated by enhancer hijacking based on tumor whole-genome and transcriptome sequencing data. HYENA detects genes whose elevated expression is associated with somatic SVs by using a rank-based regression model. We systematically analyze 1,146 tumors across 25 types of adult tumors and identify a total of 108 candidate oncogenes including many non-coding genes. A long non-coding RNA TOB1-AS1 is activated by various types of SVs in 10% of pancreatic cancers through altered 3-dimensional genome structure. We find that high expression of TOB1-AS1 can promote cell invasion and metastasis. Our study highlights the contribution of genetic alterations in non-coding regions to tumorigenesis and tumor progression.

Quatramer™ encapsulation of dual-targeted PI3-Kδ/HDAC6 inhibitor, HSB-510, suppresses growth of breast cancer.

Multiple studies have shown that the progression of breast cancer depends on multiple signaling pathways, suggesting that therapies with multitargeted anticancer agents will offer improved therapeutic benefits through synergistic effects in inhibiting cancer growth. Dual-targeted inhibitors of phosphoinositide 3-kinase (PI3-K) and histone deacetylase (HDAC) have emerged as promising cancer therapy candidates. However, poor aqueous solubility and bioavailability limited their efficacy in cancer. The present study investigates the encapsulation of a PI3-Kδ/HDAC6 dual inhibitor into hybrid block copolymers (polylactic acid-methoxy polyethylene glycol; polylactic acid-polyethylene glycol-polypropylene glycol-polyethylene glycol-polylactic acid) (HSB-510) as a delivery system to target PI3-Kδ and HDAC6 pathways in breast cancer cells. The prepared HSB-510 showed an average diameter of 96 ± 3 nm, a zeta potential of -17 ± 2 mV, and PDI of ˂0.1 with a slow and sustained release profile of PI3-Kδ/HDAC6 inhibitors in a nonphysiological buffer. In vitro studies with HSB-510 have demonstrated substantial growth inhibition of breast cancer cell lines, MDA-MB-468, SUM-149, MCF-7, and Ehrlich ascites carcinoma (EAC) as well as downregulation of phospho-AKT, phospho-ERK, and c-Myc levels. Importantly, bi-weekly treatment of Balb/c wild-type mice harboring EAC cells with HSB-510 at a dose of 25 mg/kg resulted in significant tumor growth inhibition. The treatment with HSB-510 was without any significant effect on the body weights of the mice. These results demonstrate that a novel Quatramer encapsulation of a PI3-Kδ/HDAC6 dual inhibitor (HSB-510) represents an approach for the successful targeting of breast cancer and potentially other cancer types.

Local delivery of biodegradable pirfenidone nanoparticles ameliorates bleomycin-induced pulmonary fibrosis in mice.

Our purpose was to assess sustained delivery and enhanced efficacy of pirfenidone-loaded nanoparticles after intratracheal instillation.Poly(lactide-co-glycolide) nanoparticles containing pirfenidone (NPs) were prepared and characterized. Biodistribution of NPs and solution was assessed using LC-MS after intratracheal administration in C57Bl/6 mice at 3 and 24 h and 1 week post-administration. Efficacy was tested in C57Bl/6 mice in a bleomycin-induced pulmonary fibrosis model. Mice received 10 µg pirfenidone intratracheally in solution or NPs, once a week, for 3 weeks after bleomycin administration. Drug effects were monitored on day 28. Lung hydroxyproline content, total number of cells, and numbers of macrophages, lymphocytes, and neutrophils in bronchoalveolar lavage (BAL) were assessed. Numbers of macrophages, lymphocytes, and neutrophils were assessed in the lung as well.NPs sustained significantly higher levels of pirfenidone in the lungs and BAL at 24 h and 1 week, compared to the solution group. Pirfenidone solution and NPs significantly reduced hydroxyproline levels by 57 and 81%, respectively, compared to bleomycin alone. At the end of 4 weeks, BAL cellularity was reduced by 25.4% and 56% with solution and NP treatment, respectively. The numbers of lymphocytes and neutrophils in the BAL were also reduced by 58.9 and 82.4% for solution and 74.5% and 89.7% for NPs, respectively. The number of inflammatory macrophages in the lung was reduced by 62.8% and the number of neutrophils was reduced by 59.1% in the NP group and by 37.7% and 44.5%, respectively, in the solution group, compared to bleomycin alone.In conclusion, nanoparticles sustain lung pirfenidone delivery and enhance its anti-fibrotic efficacy.

Polyamidoamine dendrimer hydrogel for enhanced delivery of antiglaucoma drugs.

Dendrimer hydrogel (DH), made from ultraviolet-cured polyamidoamine dendrimer G3.0 tethered with three polyethylene glycol (PEG, 12,000 Da)-acrylate chains (8.1% w/v) in pH 7.4 phosphate buffered saline (PBS), was studied for the delivery of brimonidine (0.1% w/v) and timolol maleate (0.5% w/v), two antiglaucoma drugs. DH was found to be mucoadhesive to mucin particles and nontoxic to human corneal epithelial cells. DH increased the PBS solubility of brimonidine by 77.6% and sustained the in vitro release of both drugs over 56-72 hours. As compared to eye drop formulations (PBS-drug solutions), DH brought about substantially higher human corneal epithelial cells uptake and significantly increased bovine corneal transport for both drugs. DH increased timolol maleate uptake in bovine corneal epithelium, stroma, and endothelium by 0.4- to 4.6-fold. This work demonstrated that DH can enhance the delivery of antiglaucoma drugs in multiple aspects and represents a novel platform for ocular drug delivery. FROM THE CLINICAL EDITOR: Dendrimer hydrogel was studied as agent for simultaneous delivery of two anti-glaucoma drugs, one hydrophobic and one hydrophilic. Superiority over standard PBS-based formulation was clearly demonstrated for both drugs. The work may be a novel platform for ocular drug delivery.

Reconstruction of cranial defect with patient-specific implants: Four different cost-effective techniques.

Cranial defects secondary to trauma, surgery or pathological causes, result in large cranial imperfection, which affects the appearance of the patient as well as results in sinking flap syndrome. Rehabilitation of such a defect can be done using prosthetic options like custom-made polymethyl methacrylate (PMMA) cranial prosthesis or surgical options like outer table calvarial graft segments. It is usually observed that the conventional moulage impression of the defective site is the most difficult task. The accuracy of the prosthesis is affected by conventional moulage impression, a moulage cast of the defect and techniques of fabricating wax pattern. Orthodox method is to mark the tentative outline of the defect and make a conventional moulage impression of the site. However, this is an arbitrary method which offers challenges to accurate replication of the borders of the defect. Recently, medical imaging and digital modeling in dentistry have paved the way for digital dental practice and additive manufacturing replacing most manual or subtractive procedures. The use of computerized tomography scan to obtain a 3 D digital image of cranial defect for fabricating a replica with rapid prototyping has markedly improved the accuracy at the margin of the defect/prosthesis interface, resulting in a better fit and optimal contour lending itself to the improved esthetic outcome. It is a more reliable method of fabricating a cranial implant prosthesis, which requires minimum adjustment when the patient is on the OT table. These case reports compare rehabilitation of cranial defect with custom-made PMMA cranial prosthesis using the conventional methods as well as rapid prototyping technique. It is seen that the rapid prototyping method is expensive but accurate and gives a better esthetic outcome.

Effect of Metal-Cored Filler Wire on Surface Morphology and Micro-Hardness of Regulated Metal Deposition Welded ASTM A387-Gr.11-Cl.2 Steel Plates.

Environmental and human-friendly welding is the need of the hour. In this context, this study explores the application of the regulated metal deposition (RMD) technique for ASTM A387-Gr.11-Cl.2 steel plates. To examine the effect of metal-cored filler wire (MCFW), MEGAFIL 237 M was employed during regulated metal deposition (RMD) welding of 6 mm thick ASTM A387-Gr.11-Cl.2 steel plates. The welding was carried out at an optimized current (A) of 100 A, voltage (V) of 13 V, and gas flow rate (GFR) of 21 L/min. Thereafter, the as-welded plates were examined for morphological changes using optical microscopy. Additionally, the micro-hardness of the as-welded plates was measured to make corroboration with the obtained surface morphologies. In addition to this, the as-welded plates were subjected to heat treatment followed by surface morphology and micro-hardness examination. A comparison was made between the as-welded and heat-treated plates for their obtained surface morphologies and microhardness values. During this, it was observed that the weld zone of as-welded plates has a dendritic surface morphology which is very common in fusion-based welding. Similarly, the weld zone of heat-treated plates has a finer and erratic arrangement of martensite. Moreover, the obtained surface morphologies in the weld zone of as-welded and heat-treated plates have been justified by their respective hardness values of 1588.6 HV and 227.3 HV.

Influence of drug solubility and lipophilicity on transscleral retinal delivery of six corticosteroids.

The influence of drug properties including solubility, lipophilicity, tissue partition coefficients, and in vitro transscleral permeability on ex vivo and in vivo transscleral delivery from corticosteroid suspensions was determined. Solubility, tissue/buffer partition coefficients for bovine sclera and choroid-retinal pigment epithelium (CRPE), and in vitro bovine sclera and sclera-choroid-retinal pigment epithelium (SCRPE) transscleral transport were determined at pH 7.4 for triamcinolone, prednisolone, dexamethasone, fluocinolone acetonide, triamcinolone acetonide, and budesonide in solution. Ex vivo and in vivo transscleral delivery was assessed in Brown Norway rats after posterior subconjunctival injection of a 1 mg/ml suspension of each corticosteroid. Corticosteroid solubility and partition coefficients ranged from ∼ 17 to 300 µg/ml and 3.0 to 11.4 for sclera and from 7.1 to 35.8 for CRPE, respectively, with the more lipophilic molecules partitioning more into both tissues. Transport across sclera and SCRPE was in the range of 3.9 to 10.7% and 0.3 to 1.8%, respectively, with the transport declining with an increase in lipophilicity. Ex vivo and in vivo transscleral delivery indicated tissue distribution in the order CRPE ≥ sclera > retina > vitreous. Tissue partitioning showed a positive correlation with drug lipophilicity (R(2) = 0.66-0.96). Ex vivo and in vivo sclera, CRPE, retina, and vitreous tissue levels of all corticosteroids showed strong positive correlation with drug solubility (R(2) = 0.91-1.0) but not lipophilicity (R(2) = 0.24-0.41) or tissue partitioning (R(2) = 0.24-0.46) when delivered as suspensions. In vivo delivery was lower in all eye tissues assessed than ex vivo delivery, with the in vivo/ex vivo ratios being the lowest in the vitreous (0.085-0.212). Upon exposure to corticosteroid suspensions ex vivo or in vivo, transscleral intraocular tissue distribution was primarily driven by the drug solubility.

Pazopanib, a multitargeted tyrosine kinase inhibitor, reduces diabetic retinal vascular leukostasis and leakage.

OBJECTIVE: To determine the efficacy of pazopanib eye drops in the streptozotocin induced diabetic retinopathy rat model. METHODS: A 0.5% w/v pazopanib suspension was prepared in phosphate buffered saline (PBS, pH 7.4) in the presence of 0.5% w/v sodium carboxymethyl cellulose. Brown Norway rats were divided into three groups (n=4) - (1) healthy, (2) diabetic, and (3) diabetic with treatment. The drug suspension was administered twice daily as eye drops to group 3 for 30 days. Efficacy parameters including the number of adherent leukocytes in the retinal vasculature (leukostasis), blood-retinal FITC-dextran leakage, and vitreous-to-plasma protein ratio were measured. RESULTS: Pazopanib suspension in the form of eye drops significantly reduced leukostasis (32%), FITC-dextran leakage (39%), and the vitreous-to-plasma protein ratio (64%) in diabetic animals compared to untreated diabetic group. CONCLUSION: Pazopanib eye drops can alleviate retinal complications of diabetic retinopathy.

Rehabilitation of Auricular Defect with Implant-Retained Auricular Prosthesis - A Case Report.

RATIONALE: Maxillofacial defect is of great concern physically, emotionally, and psychologically for a patient. However, it is an even bigger challenge for a team attempting rehabilitation, as a crucial decision has to be made between surgical approach and/or prosthetic rehabilitation. However, if both are combined, it will result in best of esthetics and function with ease of maintainance, resulting in a sucessful rehabilitation. This case report represents a case of auricular defect rehabilitated with a combination of implants and bar-retained silicone prosthesis. PATIENT CONCERN: A 38-year-old male patient with right auricular defect reported with the main concern of esthetic rehabilitation of a lost part of the external ear. DIAGNOSIS: With through evaluation and examination, a diagnosis of acquired partial auricular defect of the right side secondary to trauma was established. TREATMENT: An implant-retained auricular prosthesis was planned for this case. Surgically, three intraoral implants were placed in the mastoid bone, and after healing, bar framework was fabricated and attached. Finally, silicone prosthesis was fabricated and delivered to the patient. OUTCOME: A successful rehabilitation was carried out in this case using implants and bar attachment for retention of the silicone prosthesis. This prosthesis provided excellent retention and restored the appearance and confidence of the patient. TAKE-AWAY LESSONS: Rehabilitation of the auricular defect can be carried out with surgical approach, which involves multiple surgeries, and still, the results may not be esthetically favorable. Prosthetic rehabilitation is an option, but retention is generally a hindrance. However, implant-retained prosthesis has really paved a way for rehabilitation of the maxillofacial defect esthetically and more reliably. Cone-beam computerized tomography (CT) can be used for planning and evaluation instead of CT, which will save the patient from a lot of radiation exposure. Hence, in the maxillofacial defect, attempts should be made to explore the option of implant-retained prosthesis.

Prosthetic Management of Microstomia with Customized Dynamic Splint.

Microstomia is a clinical condition of reduced mouth opening that can be acquired or congenital in origin. Problems associated with microstomia can be related to function, esthetics, or both. Management of microstomia due to facial burns is complex due to the presence of hypertrophic and contracture scars. Available treatment options can be broadly classified as surgical, nonsurgical, or both. Splints can be used to prevent the contraction of perioral musculature or to recuperate lost mouth opening. Various intraoral or extraoral, tooth-borne or tissue-borne, and static or dynamic appliances are in clinical use, but their designs are case specific. This case report explains the management of microstomia secondary to facial burns by using a dynamic splint in combination with intralesional injections of triamcinolone acetonide and hyaluronidase.

Total Synthesis of Indolizidine Alkaloids via Nickel-Catalyzed (4 + 2) Cyclization.

A Ni-catalyzed (4 + 2) cycloaddition of alkynes and azetidinones toward piperidinones was used as key reaction in the enantioselective synthesis of naturally occurring indolizidine alkaloids. The reaction benefits from the use of an easily accessible azetidinone as an advanced and divergent intermediate to build the indolizidine core. This methodology has been applied in the total syntheses of (+)-septicine, (+)-ipalbidine, and (+)-seco-antofine to illustrate the applicability of the general approach.

Author Correction: Identification of epilepsy-associated neuronal subtypes and gene expression underlying epileptogenesis.

A Correction to this paper has been published: https://doi.org/10.1038/s41467-020-19869-5.

Identification of epilepsy-associated neuronal subtypes and gene expression underlying epileptogenesis.

Epilepsy is one of the most common neurological disorders, yet its pathophysiology is poorly understood due to the high complexity of affected neuronal circuits. To identify dysfunctional neuronal subtypes underlying seizure activity in the human brain, we have performed single-nucleus transcriptomics analysis of >110,000 neuronal transcriptomes derived from temporal cortex samples of multiple temporal lobe epilepsy and non-epileptic subjects. We found that the largest transcriptomic changes occur in distinct neuronal subtypes from several families of principal neurons (L5-6_Fezf2 and L2-3_Cux2) and GABAergic interneurons (Sst and Pvalb), whereas other subtypes in the same families were less affected. Furthermore, the subtypes with the largest epilepsy-related transcriptomic changes may belong to the same circuit, since we observed coordinated transcriptomic shifts across these subtypes. Glutamate signaling exhibited one of the strongest dysregulations in epilepsy, highlighted by layer-wise transcriptional changes in multiple glutamate receptor genes and strong upregulation of genes coding for AMPA receptor auxiliary subunits. Overall, our data reveal a neuronal subtype-specific molecular phenotype of epilepsy.

Design, Synthesis, and Biological Evaluation of Quinazolin-4-one-Based Hydroxamic Acids as Dual PI3K/HDAC Inhibitors.

A series of quinazolin-4-one based hydroxamic acids was rationally designed and synthesized as novel dual PI3K/HDAC inhibitors by incorporating an HDAC pharmacophore into a PI3K inhibitor (Idelalisib) via an optimized linker. Several of these dual inhibitors were highly potent (IC50 < 10 nM) and selective against PI3Kγ, δ and HDAC6 enzymes and exhibited good antiproliferative activity against multiple cancer cell lines. The lead compound 48c, induced necrosis in several mutant and FLT3-resistant AML cell lines and primary blasts from AML patients, while showing no cytotoxicity against normal PBMCs, NIH3T3, and HEK293 cells. Target engagement of PI3Kδ and HDAC6 by 48c was demonstrated in MV411 cells using the cellular thermal shift assay (CETSA). Compound 48c showed good pharmacokinetics properties in mice via intraperitoneal (ip) administration and provides a means to examine the biological effects of inhibiting these two important enzymes with a single molecule, either in vitro or in vivo.