Fabrication of nanocrystal forms of á´ -cycloserine and their application for transdermal and enteric drug delivery systems.

ᴅ-cycloserine (DCS), an FDA-approved medicine for the treatment of tuberculosis, is also a partial agonist at the glycine recognition site of N-methyl-ᴅ-aspartate (NMDA) receptor and has shown significant treatment efficacy for central nervous system (CNS) disorders including depression, schizophrenia, Alzheimer's disease, and post-traumatic stress disorder. The physicochemical properties of DCS, however, limit the options of formulation and medicinal applications of DCS, and warrants further investigation for the development of CNS therapeutics. Nanocrystals play an important role in pharmaceutic design and development. The properties of nanocrystals are remarkably different from their bulk material counterpart, attributed to the large surface-area-to-volume ratio which can improve the bioavailability. In this study, for the first time, DCS, a highly water-soluble compound, has formed nanocrystals and this was confirmed by scanning electronic microscopy and X-ray powder diffraction. Furthermore, DCS nanocrystals were applied to several formulations to test their stability and then to the in vitro Franz diffusion test with reservoir patch formulation as well as in vivo pharmacokinetics study with enteric capsules. We tested these formulations regarding their nanocrystal physical properties, size effect, and dissolution rate, respectively. We found that DCS nanocrystals showed good performance in the Franz diffusion test and rodent pharmacokinetic studies due to the nanoparticle size and faster dissolution as compared with the commercial DCS powder. These DCS nanocrystal formulations could offer a new approach for the development of an advanced drug delivery system for the treatment of CNS disorders.

The Development of a Regulator of Human Serine Racemase for N-Methyl-D-aspartate Function.

It is crucial to regulate N-methyl-D-aspartate (NMDA) function bivalently depending on the central nervous system (CNS) conditions. CNS disorders with NMDA hyperfunction are involved in the pathogenesis of neurotoxic and/or neurodegenerative disorders with elevated D-serine, one of the NMDA receptor co-agonists. On the contrary, NMDA-enhancing agents have been demonstrated to improve psychotic symptoms and cognition in CNS disorders with NMDA hypofunction. Serine racemase (SR), the enzyme regulating both D- and L-serine levels through both racemization (catalysis from L-serine to D-serine) and ß-elimination (degradation of both D- and L-serine), emerges as a promising target for bidirectional regulation of NMDA function. In this study, we explored using dimethyl malonate (DMM), a pro-drug of the SR inhibitor malonate, to modulate NMDA activity in C57BL/6J male mice via intravenous administration. Unexpectedly, 400 mg/kg DMM significantly elevated, rather than decreased (as a racemization inhibitor), D-serine levels in the cerebral cortex and plasma. This outcome prompted us to investigate the regulatory effects of dodecagalloyl-α-D-xylose (α12G), a synthesized tannic acid analog, on SR activity. Our findings showed that α12G enhanced the racemization activity of human SR by about 8-fold. The simulated and fluorescent assay of binding affinity suggested a noncooperative binding close to the catalytic residues, Lys56 and Ser84. Moreover, α12G treatment can improve behaviors associated with major CNS disorders with NMDA hypofunction including hyperactivity, prepulse inhibition deficit, and memory impairment in animal models of positive symptoms and cognitive impairment of psychosis. In sum, our findings suggested α12G is a potential therapeutic for treating CNS disorders with NMDA hypofunction.

Lewis Acidic Support Boosts C-C Coupling in the Pulsed Electrochemical CO2 Reaction.

Copper-oxide electrocatalysts have been demonstrated to effectively perform the electrochemical CO2 reduction reaction (CO2RR) toward C2+ products, yet preserving the reactive high-valent CuOx has remained elusive. Herein, we demonstrate a model system of Lewis acidic supported Cu electrocatalyst with a pulsed electroreduction method to achieve enhanced performance for C2+ products, in which an optimized electrocatalyst could reach ∼76% Faradaic efficiency for C2+ products (FEC2+) at ∼-0.99 V versus reversible hydrogen electrode, and the corresponding mass activity can be enhanced by ∼2 times as compared to that of conventional CuOx. In situ time-resolved X-ray absorption spectroscopy investigating the dynamic chemical/physical nature of Cu during CO2RR discloses that an activation process induced by the KOH electrolyte during pulsed electroreduction greatly enriched the Cuδ+O/Znδ+O interfaces, which further reveals that the presence of Znδ+O species under the cathodic potential could effectively serve as a Lewis acidic support for preserving the Cuδ+O species to facilitate the formation of C2+ products, and the catalyst structure-property relationship of Cuδ+O/Znδ+O interfaces can be evidently realized. More importantly, we find a universality of stabilizing Cuδ+O species for various metal oxide supports and to provide a general concept of appropriate electrocatalyst-Lewis acidic support interaction for promoting C2+ products.

Adipose stem cells preincubated with theanine exert liver regeneration through increase of stem cell paracrine VEGF and suppression of ROS, pyroptosis as well as autophagy markers in liver damage induced by N-nitrosodiethylamine.

AIMS: Liver diseases induce a severe decrease in quality of life. Stem cell based therapy shows therapeutic potential in the treatment of liver injury. Theanine is a unique amino acid found in green tea and could confer beneficial effects on cell protection. This study investigates if protective effect on the liver by stem cells preincubated with theanine is better than that from stem cells without preincubated theanine. METHODS: We transplanted theanine preincubated adipose-derived stem cells (ADSC) to male Wistar rats with liver dysfunction induced by N-nitrosodiethylamine. The viability, migration and antioxidant capabilities were performed in the ADSC pre-incubated with theanine. Hepatic functional, structural and molecular assays were determined in the animals with or without theanine preincubated ADSC. KEY FINDINGS: Cell model revealed that ADSC preincubated with green tea theanine (T-ADSC) increased cell capabilities including viability, migration and paracrine secretion. In vivo results indicated that several pathological conditions were observed in rats with liver injury induced by DEN including structural changes and expression of pyroptosis as well as autophagy markers. The above pathological conditions were improved when the rats received both ADSC and T-ADSC treatment. Furthermore, T-ADSC showed better therapeutic effect on rats with liver injury than ADSC due to significant suppression of pyroptosis markers caspase-1 and IL-1ß as well as autophagy marker LC3-II accompanied with intensive paracrine VEGF from T-ADSC. SIGNIFICANCE: Increased paracrine VEGF secretion from T-ADSC plays a crucial role in liver regeneration. A future clinical study may be designed for further verification of these experimental in vivo findings.

L-Theanine-Treated Adipose-Derived Mesenchymal Stem Cells Alleviate the Cytotoxicity Induced by N-Nitrosodiethylamine in Liver.

BACKGROUND: Liver inflammation is the main cause of severe liver diseases, including liver fibrosis, steatohepatitis, cirrhosis and hepatocellular carcinoma. Cell therapy topics are receiving increasingly more attention. The therapeutic applications of mesenchymal stem cells (MSC) have become one of the most discussed issues. While other stem cells have therapeutic effects, they have only one or two clinical applications. MSCs are responsible for repairing a variety of tissue injuries. Moreover, MSCs could be derived from several sources, including adipose tissue. MSCs are usually more abundant and easier to obtain compared to other stem cells. METHODS: To prove the concept that MSCs have homing ability to the injured tissue and assist in tissue repair, we examined the effects of intravenous injected adipose-derived mesenchymal stem cells (ADSCs) in a N-nitrosodiethylamine (DEN)-induced liver injury rat model. RESULTS: The significant repairing ability of ADSCs was observed. The levels of fibrosis, apoptosis, and tumorigenesis in the DEN-injured liver tissues all decreased after ADSC treatment. Furthermore, to enhance the therapeutic effects of ADSCs, we pretreated them with L-theanine, which promotes the hepatocyte growth factor secretion of ADSC, and therefore improved the healing effects on injured liver tissue. CONCLUSION: ADSCs, especially L-theanine-pretreated ADSCs, have anti-inflammation, anti-apoptosis, and anti-tumorigenesis effects on the N-nitrosodiethylamine-induced liver injury rat model.

Global epidemiology of vaccine-derived poliovirus 2016-2021: A descriptive analysis and retrospective case-control study.

Background: Vaccine derived poliovirus (VDPV) remains a major barrier to polio eradication, and recent growing emergences are concerning. This paper presents the global epidemiology of circulating VDPV (cVDPV) by exploring associations between demographic and socioeconomic factors with its recent rise. Methods: Data on reported cVDPV cases and isolates between January 1 2016 and June 30 2021 were compiled from EPIWATCH, an open-source observatory for outbreak scanning and analysis, the World Health Organisation (WHO) and ProMed, and analysed descriptively. Reports containing cVDPV case information were included while duplicates and defective links were excluded. Data collection occurred from April 5 2021 to July 16 2021. To identify factors associated with cVDPV, a retrospective case-control study comparing socioeconomic profiles of countries which reported cVDPV with those that did not was undertaken with weighted logistic regression analysis. Findings: cVDPV caused by serotype 2 poliovirus was the predominant strain (95%) of 1818 total human cVDPV cases reported. Of 40 countries reporting cVDPV cases or isolates, 22 (55%) had polio vaccination coverages below 80%. Low vaccination coverage (Adjusted OR = 83·41, 95% CI: [5·01, 1387·71], p = 0·0020) was found to be associated with increased odds of reporting cVDPV after adjusting for confounding effects of GDP per capita, female adult literacy rates, maternal mortality rate, and Global Peace Index. Interpretation: Our findings reinforce the importance of maintaining high levels of vaccination, as risk of re-emergence rises when immunity wanes. Interventions to increase vaccination and standards of living in developing countries, coupled with robust surveillance are required if humanity hopes to eradicate polio in the near future. Funding: This research was supported by the MRFF 2021 Frontier Health and Medical Research Grant (ID RFRHPI000280), Department of Health, the Australian Government.

Cinnamaldehyde decreases the invasion and u-PA expression of osteosarcoma by down-regulating the FAK signalling pathway.

Cancer metastasis is the major cause of the high mortality risk of patients with osteosarcoma. Cinnamaldehyde has been shown to exhibit multiple tumour-suppressing activities, but its role in human osteosarcoma is not yet completely defined. In this study, the antimetastatic effect of cinnamaldehyde on highly metastatic human osteosarcoma cells was observed in vitro and in vivo using Saos-2 and 143B cells. Cinnamaldehyde reduced the activity and protein level of urokinase-type plasminogen activator (u-PA) and suppressed the invasion ability of osteosarcoma cells by inhibiting the phosphorylation of focal adhesion kinase. In addition, cinnamaldehyde reduced cell movement, cell-matrix adhesion, and the expression of the mesenchymal markers of epithelial-to-mesenchymal transition, namely, fibronectin and N-cadherin. Importantly, the oral administration of cinnamaldehyde remarkably suppressed the pulmonary metastasis of osteosarcoma in mice. Results indicated that cinnamaldehyde has therapeutic potential for inhibiting osteosarcoma metastasis.

NO Reduction to N2O Triggered by a Dinuclear Dinitrosyl Iron Complex via the Associated Pathways of Hyponitrite Formation and NO Disproportionation.

In spite of the comprehensive study of the metal-mediated conversion of NO to N2O disclosing the conceivable processes/mechanism in biological and biomimetic studies, in this study, the synthesis cycles and mechanism of NO reduction to N2O triggered by the electronically localized dinuclear {Fe(NO)2}10-{Fe(NO)2}9 dinitrosyl iron complex (DNIC) [Fe(NO)2(µ-bdmap)Fe(NO)2(THF)] (1) (bdmap = 1,3- bis(dimethylamino)-2-propanolate) were investigated in detail. Reductive conversion of NO to N2O triggered by complex 1 in the presence of exogenous ·NO occurs via the simultaneous formation of hyponitrite-bound {[Fe2(NO)4(µ-bdmap)]2(κ4-N2O2)} (2) and [NO2]--bridged [Fe2(NO)4(µ-bdmap)(µ-NO2)] (3) (NO disproportionation yielding N2O and complex 3). EPR/IR spectra, single-crystal X-ray diffraction, and the electrochemical study uncover the reversible redox transformation of {Fe(NO)2}9-{Fe(NO)2}9 [Fe2(NO)4(µ-bdmap)(µ-OC4H8)]+ (7) ↔ {Fe(NO)2}10-{Fe(NO)2}9 1 ↔ {Fe(NO)2}10-{Fe(NO)2}10 [Fe(NO)2(µ-bdmap)Fe(NO)2]- (6) and characterize the formation of complex 1. Also, the synthesis study and DFT computation feature the detailed mechanism of electronically localized {Fe(NO)2}10-{Fe(NO)2}9 DNIC 1 reducing NO to N2O via the associated hyponitrite-formation and NO-disproportionation pathways. Presumably, the THF-bound {Fe(NO)2}9 unit of electronically localized {Fe(NO)2}10-{Fe(NO)2}9 complex 1 served as an electron buffering reservoir for accommodating electron redistribution, and the {Fe(NO)2}10 unit of complex 1 acted as an electron-transfer channel to drive exogeneous ·NO coordination to yield proposed relay intermediate κ2-N,O-[NO]--bridged [Fe2(NO)4(µ-bdmap)(µ-NO)] (A) for NO reduction to N2O.

Attribute-Aware Recommender System Based on Collaborative Filtering: Survey and Classification.

Attribute-aware CF models aim at rating prediction given not only the historical rating given by users to items but also the information associated with users (e.g., age), items (e.g., price), and ratings (e.g., rating time). This paper surveys work in the past decade to develop attribute-aware CF systems and finds that they can be classified into four different categories mathematically. We provide readers not only with a high-level mathematical interpretation of the existing work in this area but also with mathematical insight into each category of models. Finally, we provide in-depth experiment results comparing the effectiveness of the major models in each category.

Evidence of tandem repeat and extra thiol-groups resulted in the polymeric formation of bovine haptoglobin: a unique structure of Hp 2-2 phenotype.

Human plasma Hp is classified as 1-1, 2-1, and 2-2. They are inherited from two alleles Hp 1 and Hp 2, but there is only Hp 1 in almost all the animal species. Hp 2-2 molecule is extremely large and heterogeneous associated with the development of inflammatory-related diseases. In this study, we expressed entire bovine Hp in E. coli as a alphabeta linear form. Interestingly, the antibodies prepared against this form could recognize the subunit of native Hp. In stead of a complicated column method, the antibody was able to isolate bovine Hp via immunoaffinity and gel-filtration columns. The isolated Hp is polymeric containing two major molecular forms (660 and 730 kDa). Their size and hemoglobin binding complex are significantly larger than that of human Hp 2-2. The amino-acid sequence deducted from the nucleotide sequence is similar to human Hp 2 containing a tandem repeat over the alpha chain. Thus, the Hp 2 allele is not unique in human. We also found that there is one additional -SH group (Cys-97) in bovine alpha chain with a total of 8 -SH groups, which may be responsible for the overall polymeric structure that is markedly different from human Hp 2-2. The significance of the finding and its relationship to structural evolution are also discussed.

An improved method for haptoglobin 1-1, 2-1, and 2-2 purification using monoclonal antibody affinity chromatography in the presence of sodium dodecyl sulfate.

Human haptoglobin (Hp) is classified as three phenotypes: Hp 1-1, 2-1, and 2-2. Previously, we had isolated this protein by affinity columns using either hemoglobin or monoclonal antibody (mAb) prepared against Hp beta-chain (clone 8B1-3A). The isolated Hp from both methods, however, contaminates plasma apolipoprotein A-I (apoA-I). In the present report, we have developed a novel affinity column procedure using an mAb prepared against alpha-chain of Hp (clone 3H8) for Hp purification. Plasma was first chromatographed onto the column followed by a normal wash with a buffer containing 0.12 M NaCl and 0.02 M phosphate, pH 7.4 (PBS). The bound proteins were then prewashed with a 0.04% sodium dodecyl sulfate (SDS)-PBS, pH 7.4, to remove the low-affinity bound apoA-I from Hp. Finally, the bound Hp was eluted with a 0.1% SDS-PBS, pH 11, and collected in tubes containing 1 M Tris-HCl, pH 6.8. As a result, the isolated Hp was devoid of apoA-I and was able to retain the biological function by forming an Hp-hemoglobin complex. The homogeneity of each isolated Hp 1-1, 2-1, or 2-2 was greater than 95% with an yield greater than 50%. The procedure described here is significantly improved in time consumption, recovery, and purity. The rationale, design, and optimization for each step are described in detail.