Assessing antiviral treatment efficacy and risk factors for severe COVID-19 in kidney transplant recipients during the Omicron subvariant-dominant period: a retrospective study.

BACKGROUND: Kidney transplant recipients (KTRs) are at risk of severe coronavirus disease 2019 (COVID-19), and even now that Omicron subvariants have become dominant, cases of severe disease are certain to occur. The aims of this retrospective study were to evaluate the efficacy of antiviral treatment for COVID-19 and to identify risk factors for severe disease in KTRs during Omicron subvariant-dominant periods. METHODS: A total of 65 KTRs diagnosed with COVID-19 who received antiviral treatment between July 2022 and September 2023 were analyzed. Mild cases received oral molnupiravir (MP) as outpatient therapy, while moderate or worse cases received intravenous remdesivir (RDV) as inpatient therapy. In principle, mycophenolate mofetil was withdrawn and switched to everolimus. We investigated the efficacy of antiviral treatment and compared the clinical parameters of mild/moderate and severe/critical cases to identify risk factors for severe COVID-19. RESULTS: Among 65 cases, 49 were mild, 6 were moderate, 9 were severe, and 1 was of critical severity. MP was administered to 57 cases; 49 (86%) improved and 8 (14%) progressed. RDV was administered to 16 cases; 14 (87%) improved and 2 (13%) progressed. Seventeen (26%) cases required hospitalization, and none died. Comparisons of the severe/critical group (n = 10) with the mild/moderate group (n = 55) demonstrated that the severe/critical group had a significantly higher median age (64 vs. 53 years, respectively; p = 0.0252), prevalence of diabetes (70% vs. 22%, respectively; p = 0.0047) and overweight/obesity (40% vs. 11%, respectively; p = 0.0393), as well as a significantly longer median time from symptom onset to initial antiviral therapy (3 days vs. 1 day, respectively; p = 0.0026). Multivariate analysis showed that a longer time from symptom onset to initial antiviral treatment was an independent risk factor for severe COVID-19 (p = 0.0196, odds ratio 1.625, 95% confidence interval 1.081-2.441). CONCLUSION: These findings suggest that a longer time from symptom onset to initial antiviral treatment is associated with a higher risk of severe COVID-19 in KTRs. Initiating antiviral treatment as early as possible is crucial for preventing severe outcomes; this represents a valuable insight into COVID-19 management in KTRs.

Optimum conditions for high-speed solid-liquid separation by ballasted flocculation.

In the ballasted flocculation, high-speed sedimentation of suspensions is achieved using a microsand as a ballast material and a polymer flocculant combined with microflocs made of polyaluminum chloride (PAC) as an inorganic coagulant. In this study, three turbid water samples containing kaolin clay (kaolin concentration: 20, 200, and 500 mg/L) were treated by coagulation-sedimentation and ballasted flocculation. The effects of pH and PAC dosage, which are the controlling parameters for coagulation, and the microsand (silica sand) and polymer dosages, which are the controlling parameters for ballasted treatment, on the treatment efficiency and floc settling velocity were examined. The floc settling velocity under the optimum conditions was 17 times higher than that of the conventional coagulation-sedimentation process using PAC. The turbidity was 0.54 turbidity unit (TU) (TU as the kaolin standard), and its removal efficiency was 99.7%. Furthermore, turbid water samples with different kaolin concentrations (20 and 500 mg/L) were treated via the ballasted flocculation. In this study, fundamental information on the optimization of each dosage condition of coagulant, ballast, and polymer and pH condition in ballasted flocculation was obtained, and the removal mechanisms under optimal, underoptimistic and overoptimistic conditions were proposed.

NMR-guided directed evolution.

Directed evolution is a powerful tool for improving existing properties and imparting completely new functionalities to proteins1-4. Nonetheless, its potential in even small proteins is inherently limited by the astronomical number of possible amino acid sequences. Sampling the complete sequence space of a 100-residue protein would require testing of 20100 combinations, which is beyond any existing experimental approach. In practice, selective modification of relatively few residues is sufficient for efficient improvement, functional enhancement and repurposing of existing proteins5. Moreover, computational methods have been developed to predict the locations and, in certain cases, identities of potentially productive mutations6-9. Importantly, all current approaches for prediction of hot spots and productive mutations rely heavily on structural information and/or bioinformatics, which is not always available for proteins of interest. Moreover, they offer a limited ability to identify beneficial mutations far from the active site, even though such changes may markedly improve the catalytic properties of an enzyme10. Machine learning methods have recently showed promise in predicting productive mutations11, but they frequently require large, high-quality training datasets, which are difficult to obtain in directed evolution experiments. Here we show that mutagenic hot spots in enzymes can be identified using NMR spectroscopy. In a proof-of-concept study, we converted myoglobin, a non-enzymatic oxygen storage protein, into a highly efficient Kemp eliminase using only three mutations. The observed levels of catalytic efficiency exceed those of proteins designed using current approaches and are similar with those of natural enzymes for the reactions that they are evolved to catalyse. Given the simplicity of this experimental approach, which requires no a priori structural or bioinformatic knowledge, we expect it to be widely applicable and to enable the full potential of directed enzyme evolution.

Aqueous Solutions of a Porous Host-Poly-L-lysine Complex with Information on Solids as Different Fluorescence by Guests.

N,N'-Dipyrid-3-yl-1,4,5,8-naphthalenediimide linked to two tris(pentafluorophenyl)borane (1) exhibits strong fluorescence emission in the solid state by the formation of a charge-transfer complex containing small aromatic guest molecules. Hydrophobic 1 was dissolved in water by mixing with poly-L-lysine (PLL) as a solubilizing agent. The 1-PLL complex could include small aromatic guest molecules in water, significantly increasing the fluorescence. The fluorescence maxima of 1 in aqueous solution and solid state were different depending on the guest molecule. Therefore, compound 1 was prepared as aqueous solution with information of fluorescence on solids by complexation with PLL.

Advances in Understanding the Mechanism of Ophthalmic Viscosurgical Device Retention in the Anterior Chamber or on the Corneal Surface during Ocular Surgery.

Retention durability, especially in the eye, is one of the most important properties of ophthalmic viscosurgical devices (OVDs) during ocular surgery. However, the information on the physical properties of OVDs is insufficient to explain their retention durability. The purpose of this study is to clarify the mechanism of OVD retention to improve understanding of the behavior of OVDs during ocular surgery. To elucidate the mechanism of OVD retention, we have developed a new test method for measuring repulsive force. As a result, the maximum repulsive force of OVDs was positively and well correlated with the retention durability of investigated OVDs. Consequently, we demonstrated that the repulsive force could be used as an index of retention durability on the ocular surface and in the eye. We directly compared the intraocular retention durability of three OVDs (Shellgan, Viscoat, and Opegan-Hi) in ex vivo porcine eyes. Opegan-Hi was immediately removed from the anterior chamber, but Shellgan and Viscoat remained largely in the anterior chamber as determined by fluorescence imaging. These results showed that the intraocular retention behavior of OVDs was similar to their ocular surface behavior in our previous report, suggesting that retention durability is dependent on the OVD itself. The retention durability of Shellgan seemed to be higher than that of Viscoat, and the maximum repulsive force of Shellgan was 1.35-fold higher than that of Viscoat. Therefore, the repulsive force might be a useful index for assessing the difference in the retention durability between OVDs such as Shellgan and Viscoat.

The structure of SeviL, a GM1b/asialo-GM1 binding R-type lectin from the mussel Mytilisepta virgata.

SeviL is a recently isolated lectin found to bind to the linear saccharides of the ganglioside GM1b (Neu5Ac[Formula: see text](2-3)Gal[Formula: see text](1-3)GalNAc[Formula: see text](1-4)Gal[Formula: see text](1-4)Glc) and its precursor, asialo-GM1 (Gal[Formula: see text](1-3)GalNAc[Formula: see text](1-4)Gal[Formula: see text](1-4)Glc). The crystal structures of recombinant SeviL have been determined in the presence and absence of ligand. The protein belongs to the [Formula: see text]-trefoil family, but shows only weak sequence similarity to known structures. SeviL forms a dimer in solution, with one binding site per subunit, close to the subunit interface. Molecular details of glycan recognition by SeviL in solution were analysed by ligand- and protein-based NMR techniques as well as ligand binding assays. SeviL shows no interaction with GM1 due to steric hindrance with the sialic acid branch that is absent from GM1b. This unusual specificity makes SeviL of great interest for the detection and control of certain cancer cells, and cells of the immune system, that display asialo-GM1.

[Access to grocery stores and nutrition/food intake observed in the National Health and Nutrition Survey: Focusing on the substitution-complementary relation].

Objective　This study aimed to identify the characteristics of nutrition and food intake among people who have limited access to grocery stores (hereinafter, "people with limited access").Method　Data from the 2011 National Health and Nutrition Survey and 2011 Comprehensive Survey of Living Conditions were compiled using a data-linkage method. These are the only surveys that contain data regarding people's access to grocery stores. Nutrition and food intake among people with limited access were examined using an econometric method targeting 1,051 women aged 65 years and older. The objective variables for the analysis were caloric intake (kcal) from energy-providing nutrients, namely, proteins, fats, and carbohydrates, and 17 items in different food groups (g/1,000 kcal). The analysis used the seemingly unrelated regressions model, a simultaneous equations model designed to address endogeneity through simultaneous determinations of objective variables. This model indicated, by way of coefficients, the influence of the factors (variables) that define caloric intake from each nutrient and food group. The substitution-complementary relation among the nutrients and among the food groups was expressed as a correlation matrix between error terms.Results　The characteristics of people with limited access were examined targeting women aged 65 years and older with respect to their access to grocery stores and intake of energy-providing nutrients. The results indicated that their caloric intake (kcal) of carbohydrates was significantly high, whereas their caloric intake (kcal) of fats was significantly low. Their caloric intake by food group (g/1,000 kcal) also confirmed similar results: their intake of grains was high, but that of fats was low. Thus, the results indicated a strong likelihood that people with limited access, even after accounting for the substitution-complementary relation, had a diet that was too high in carbohydrates.Conclusion　People with limited access tended to have a diet that was too high in carbohydrates. This tendency had a strong likelihood to be because of not simply the prices or their preferences but their food environment-that is, their limited access to grocery stores. The food environment prescribes people's diet, even when individuals' financial situations are taken into account. Therefore, the study indicated the necessity for chain store operators to cooperate with one another and with the government to create an environment that facilitates shopping-support services.

Comparison of Objective and Perceived Access to Food Stores Associated with Intake Frequencies of Vegetables/Fruits and Meat/Fish among Community-Dwelling Older Japanese.

This cross-sectional study aimed to compare access to the nearest food stores with perceived access associated with intake frequencies of vegetables/fruits and meat/fish among older Japanese people. We used intake frequencies of vegetables/fruits and meat/fish from a self-administered questionnaire in the Japan Gerontological Evaluation Study among 83,384 adults aged over 65 years. We defined distance over 1 km as poor objective access in community level. We performed multilevel regression analysis to investigate the association of objective and perceived access with intake frequencies of vegetables/fruits and meat/fish, respectively. Participants who lived in poor objective access had a significantly higher intake frequency of vegetables/fruits than those who lived in good access. In contrast, residents with poor perceived access consumed lower frequent intake of vegetables/fruits (beta coefficient (standard error) 0.086 (0.021) for objective access; -0.093 (0.009) for perceived access). There was no significant association between objective access and intake frequency of meat/fish, but poor perceived access showed a significant association with lower intake frequency of meat/fish. There was inconsistency between objective and perceived measurement of access to food stores associated with dietary habits among older Japanese adults. Food access needs to be comprehensively assessed, while considering characteristics of measurements.

The Association between Self-Reported Difficulty of Food Access and Nutrient Intake among Middle-Aged and Older Residents in a Rural Area of Japan.

We investigated the association of self-reported difficulty of food access, accounting for the perception of food-store accessibility, with nutrient intake among 474 inhabitants (145 men and 329 women) aged ≥40 y in a rural area of Japan. Information on self-reported difficulty of food access and dietary intake was obtained via a self-administrated questionnaire. Analysis of covariance was performed to evaluate the adjusted associations between difficulty of food access and percentages of total energy (i.e., protein, fat, and carbohydrates). Among men, the adjusted means of percent energy from fat in the "difficulty of food access" group (19.2% energy) were significantly lower (by 2.4%) and the percent energy from carbohydrates for this group (57.3% energy) was significantly higher (by 3.3%) than for the "non-difficulty" group. In conclusion, this study found nutritional balance among residents experiencing difficulty of food access results in lower fat and higher carbohydrate intake than for those with non-difficulty of food access among middle-aged and older Japanese men in a rural area.

Inhibition of PC3 human prostate cancer cell proliferation, invasion and migration by eicosapentaenoic acid and docosahexaenoic acid.

The n-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), found in fish oil, exert a number of beneficial effects, and they are used in the treatment of hyperlipidemia. In recent years, EPA and DHA have been found to affect cancer cell proliferation. In the present study, PC3 cells, which are androgen-independent prostate cancer cells that resemble castration-resistant prostate cancer cells, were used to investigate a possible novel treatment for castration-resistant prostate cancer. The PC3 cells were cultured and incubated with various concentrations of EPA or DHA. Cancer proliferation was confirmed by trypan blue microscopy. Invasion and migration assays were used in the upper chamber in PC3 cells, and serum-free medium and various concentrations of EPA or DHA were placed in the lower chamber in serum-containing medium. EPA and DHA decreased PC3 cell proliferation, invasion and migration. The effect of EPA on PC3 cells was dose-dependent and significant differences were observed at concentrations of 100 and 200 µg/ml. The effect of DHA on PC3 cells was similar to that of EPA. In the migration assay, EPA exerted almost no effects at 25 µg/ml, but migration was reduced at 50 µg/ml. Similar to EPA, DHA exerted almost no effects at 25 µg/ml, but further reduction was observed at the 50 µg/ml concentration. In the invasion assay, EPA at 25 µg/ml was not significantly different from the control, but suppressed invasion at 50 µg/ml. DHA decreased invasion compared with the control at 25 µg/ml, whereas invasion was significantly reduced at a DHA concentration of 50 µg/ml. In conclusion, it was demonstrated that EPA and DHA were effective in decreasing the proliferation, invasion and migration of prostate PC3 cancer cells. However, the detailed underlying mechanisms have not yet been fully elucidated.

Well-structured bimetallic surface capable of molecular recognition for chemoselective nitroarene hydrogenation.

Unprecedented molecular recognition ability governed by a simple bimetallic surface is reported. A series of Rh-based ordered alloys supported on silica gel (Rh x M y /SiO2, where M is Bi, Fe, Ga, Ge, In, Ni, Pb, Sb, Sn, or Zn) were tested in the hydrogenation of nitrostyrene to form aminostyrene. RhIn/SiO2 showed remarkably high catalytic activity and good selectivity under 1 atm H2 at room temperature. Moreover, various other nitroarenes containing carbonyl, cyano, or halo moieties were selectively hydrogenated into the corresponding amino derivatives using RhIn/SiO2. Kinetic study and density functional theory (DFT) calculations revealed that the high selectivity originates from RhIn/SiO2 adsorbing nitro groups much more favorably than vinyl groups. In addition, the DFT calculations indicated that the RhIn ordered alloy presents concave Rh rows and convex In rows on its surface, which are able to capture the nitro group with end-on geometry while effectively minimizing vinyl-π adsorption. Thus, the specific and highly ordered surface structure of RhIn enables the chemoselective molecular recognition of nitro groups over vinyl groups through geometric and chemical effects.

Regeneration of intervertebral disc by the intradiscal application of cross-linked hyaluronate hydrogel and cross-linked chondroitin sulfate hydrogel in a rabbit model of intervertebral disc injury.

The degeneration of intervertebral disc (IVD) is a major cause of low back pain. However, there is no satisfactory preventive treatment for degenerative disc disease (DDD). In this study, we examined the effects of a novel cross-linked hyaluronate hydrogel and cross-linked chondroitin sulfate (CS) hydrogel on a rabbit model of IVD injury. We injected 300 microl of phosphate buffer saline, 1% sodium hyaluronate, cross-linked hyaluronate hydrogel, or cross-linked CS hydrogel into the injured IVDs. One, three or six months after treatment, the whole spinal columns were dissected and magnetic resonance (MR) images of the IVDs were examined. It was noted that the IVD, which was injected with cross-linked hyaluronate hydrogel or cross-linked CS hydrogel mostly retained the normal signal intensity of the MR images. These IVDs exhibited a higher degree of staining with safranin-O than the control discs or 1% sodium hyaluronate-injected discs, suggesting that the intradiscal application of cross-linked hyaluronate hydrogel or cross-linked CS hydrogel probably inhibits the degenerative cascade of the DDD. The intradiscal administration of these drugs is safe, easy and costs less. In the near future, these intradiscal injections may become the standard therapy for the treatment of DDD instead of the spine surgeries.

New artificial nerve conduits made with photocrosslinked hyaluronic acid for peripheral nerve regeneration.

For peripheral nerve regeneration, three-dimensional distribution and growth of cells within the porous scaffold are of clinical significance. We demonstrate that cultured rat Schwann cells and neurospheres grow in vitro on new artificial nerve conduits made with photocrosslinked hyaluronic acid (HA). HA tubular conduits have an inner diameter of 1.2 mm with porous nano-structure of 50 microm. After 3 weeks of cultivation, HA conduits remained circular with a round lumen, and construct of cell-conduits maintained the size and shape of the original architecture of the tube. HA itself has the function to facilitate a pathway for cellular and axonal ingrowth during peripheral nerve regeneration. These findings provide the feasibility of using the HA conduits for better cell adhesion and differentiation, leading to axonal regeneration in peripheral nerve reconstruction.

[The application of cross-linked hyaluronate hydrogel to trabeculectomy].

PURPOSE: We investigated the possibility of applying cross-linked hyaluronate hydrogel (HA gel) during trabeculectomy in rabbit eyes. SUBJECTS AND METHODS: 1. We injected 0.9% salt solution (n = 3), Opegan-HI (n = 3), or HA gel (n = 3) into the subconjunctiva to make a follicle, and investigated its size. 2. After making a limbal-based conjunctival flap and a scleral flap, we injected HA gel or 0.9% salt solution into the subconjunctiva of rabbit eyes and sutured each flap (n = 4 each). Three weeks after the operation, we incised the conjunctiva and investigated the case of peeling away the conjunctival flap or the scleral flap. 3. We performed trabeculectomy with and without subconjunctival HA gel (n = 7 and 6, respectively), and compared the reduction of intraocular pressure between the two groups. RESULTS: The results showed that the formation of the follicle was excellent and it was easy to peel away the adhesion. The reduction of intraocular pressure was statistically significant 4 weeks after the operation in which the HA gel was used. CONCLUSIONS: It could be useful to apply HA gel in trabeculectomy to prevent adhesion.