UiO-66/AgNPs Coating for Dental Implants in Preventing Bacterial Infections

Titanium (Ti)-based biomaterials lack inherent antimicrobial activities, and the dental plaque formed on the implant surface is one of the main risk factors for implant infections. Construction of an antibacterial surface can effectively prevent implant infections and enhance implant success. Silver nanoparticles (AgNPs) exhibit broad antibacterial activity and a low tendency to induce drug resistance, but AgNPs easily self-aggregate in the aqueous environment, which significantly impairs their antibacterial activity. In this study, UiO-66/AgNP (U/A) nanocomposite was prepared, where zirconium metal-organic frameworks (UiO-66) were employed as the confinement matrix to control the particle size and prevent aggregation of AgNPs. The bactericidal activity of U/A against methicillin-resistant Staphylococcus aureus and Escherichia coli increased nearly 75.51 and 484.50 times compared with individually synthesized Ag. The antibacterial mechanism can be attributed to the enhanced membrane rupture caused by the ultrafine AgNPs on UiO-66, leading to protein leakage and generation of intracellular reactive oxygen species. Then, U/A was loaded onto Ti substrates (Ti-U/A) by using self-assembly deposition methods to construct an antibacterial surface coating. Ti-U/A exhibited excellent antibacterial activities and desired biocompatibility both in vitro and in vivo. The U/A nanocomposite coating technique is thus expected to be used as a promising surface modification strategy for Ti-based dental implants for preventing dental implant infections.

Achievement of Target Gain Larger than Unity in an Inertial Fusion Experiment

On December 5, 2022, an indirect drive fusion implosion on the National Ignition Facility (NIF) achieved a target gain G_{target} of 1.5. This is the first laboratory demonstration of exceeding "scientific breakeven" (or G_{target}>1) where 2.05 MJ of 351 nm laser light produced 3.1 MJ of total fusion yield, a result which significantly exceeds the Lawson criterion for fusion ignition as reported in a previous NIF implosion [H. Abu-Shawareb et al. (Indirect Drive ICF Collaboration), Phys. Rev. Lett. 129, 075001 (2022)PRLTAO0031-900710.1103/PhysRevLett.129.075001]. This achievement is the culmination of more than five decades of research and gives proof that laboratory fusion, based on fundamental physics principles, is possible. This Letter reports on the target, laser, design, and experimental advancements that led to this result.

Final Results from a Prospective Randomized Pilot Trial of Stereotactic Body Radiation Therapy vs. Radiofrequency Ablation for the Management of Small Renal Masses (RADSTER)

PURPOSE/OBJECTIVE(S)

The benefits of stereotactic body radiation therapy (SBRT) as a primary treatment modality for small renal masses (SRMs) ≤4cm are unclear. Our objective was to evaluate both SBRT and radiofrequency ablation (RFA) for SRMs to determine the utility of a future Phase III randomized controlled trial (RCT).

MATERIALS/METHODS

Patients with SRMs who declined active surveillance, surgery or were deemed inoperable were recruited at a single tertiary academic center. After meeting inclusion/exclusion criteria, participants were assigned 1:1 to SBRT or RFA, with crossover allowed if technical or patient factors precluded either treatment. SBRT included an initial simulation and a single delivered fraction of 25 Gy to the planning target volume. RFA was conducted percutaneously with 2 cycles of up to 8 minutes each upon reaching target temperature. Renal protocol imaging (CT or MRI) was completed q3 months (up to 1 year) post-procedure. Diagnostic and 1-year renal biopsies were also required. The objective of this trial was feasibility of randomization, with the aim of recruiting 24 patients based on this assumption.

RESULTS

From January 2020 to June 2021, 33 patients were screened, with 24 recruited and initially randomized (SBRT = 12; RFA = 12). Median age was 67 years (53-85) and 17/24 were male. Seventeen patients had clear cell renal cell carcinoma (RCC), 6 had papillary RCC, and 1 had chromophobe RCC. Following randomization, a total of 14 patients had SBRT, 7 had RFA, and 3 declined treatments. Crossover mainly occurred from RFA to SBRT due to technical inability to perform RFA. One grade 2 acute pain flare occurred in the SBRT group (none in the RFA group). No late toxicity up to 1 year was reported in either group. At 1 year, no radiographic local failure (RECIST) was observed, although RFA patients were more likely to have loss of arterial enhancement (83.3% vs 23%, p = 0.041). Mean reduction of estimated glomerular filtration rate was similar at 1 year (RFA -3 mL/min, SBRT -5.3 mL/min, p = 0.7). Biopsies were performed in 20/24 patients at 1 year, on per-protocol analysis 7/7 (100%) of RFA patients had no evidence of residual RCC, whereas with SBRT 4/13 (31%) patients had no evidence of residual RCC, 2/13 (15%) had scant/minimal residual disease, and 7/13 (54%) had evidence of RCC. No patients developed distant failure or death from RCC during follow-up.

CONCLUSION

Recruitment, randomization and follow-up of patients with SRMs was feasible in this study. More patients received SBRT compared to RFA, highlighting the need for thorough multidisciplinary evaluation prior to randomization. Both treatments have excellent safety profiles, with RFA demonstrating initial higher rates of pathological/radiologic response, however long-term follow-up is required. This trial supports the need for a large scale RCT with appropriate radiographic and pathological endpoints built in.

Evaluation of Volumetric Response Assessment from Stereotactic Ablative Radiotherapy (SABR) for Renal Cell Carcinoma (RCC)

PURPOSE/OBJECTIVE(S)

SABR has recently been proven to be a safe, effective treatment for RCC. However, long term follow-up assessment can be challenging as traditional methods of assessment such as RECIST may not identify tumor response, and delayed responses to SABR are common. The purpose of this study was to quantify SABR response using volumetric changes from baseline throughout follow-up.

MATERIALS/METHODS

We conducted a single-center retrospective study including all patients treated with SABR for RCC from 2013 to 2020. Patients were included if they had no metastatic disease, no resection after SABR, and had follow-up imaging available for at least 12 months following SABR. All available follow-up CT scans were collected and aligned, and tumors were contoured on all follow-up scans to measure volume and maximum linear dimension. Response to SABR was assessed by comparing tumor volume at follow-up to the initial tumor volume at the time of CT simulation.

RESULTS

Twenty-four patients with 25 tumors were included. The dose was between 25Gy and 42Gy in 1-5 fractions; 64% of tumors received 35Gy in 5 fractions. Follow-up time was between 16 and 67 months; median follow-up was 32 months. A total of 164 follow-up scans were contoured. The relative volume and standard deviation (compared to baseline) at 3, 6, 9, 12, 24, 36, and 48 months was 0.76 (SD 0.22), 0.80 (SD 0.27), 0.76 (SD 0.32), 0.75 (SD 0.26), 0.61 (SD 0.33), 0.53 (SD 0.41), and 0.34 (SD 0.22) respectively. One tumor (4%) showed continued growth after SABR, while 24 of 25 tumors (96%) had durable volumetric response after SABR. Eighteen of 25 tumors (72%) decreased in volume on first follow-up scan and continued to shrink, while 6 of 25 tumors (24%) displayed growth after SABR (average 33% increase in volume) before shrinking below their initial volume. The median time to any volumetric response was 3.5 months (range 2-19 months). Nineteen tumors (76%) had 30% volumetric response. Median time to 30% volumetric response was 7 months (range 3-55 months). In contrast, 12 tumors (48%) had 30% decrease in maximum linear size, with median time to 30% linear response of 16 months (range 4-42 months). Thirteen tumors (52%) had 50% volumetric response; median time to 50% volumetric response was 11 months (range 4-37 months). Among tumors for which contrast-enhanced scans were available, 15 of 22 tumors (68%) displayed arterial enhancement at their most recent follow-up scan, at a median time of 24 months after SABR.

CONCLUSION

SABR is a highly effective treatment for RCC, achieving durable local control in 96% of cases. Initial growth after SABR is common before volumetric response occurs. Volumetric response is more frequent and occurs earlier than decrease in maximum linear dimension, even with persistent arterial contrast enhancement following SABR.

A high-quality genome compendium of the human gut microbiome of Inner Mongolians

Metagenome-based resources have revealed the diversity and function of the human gut microbiome, but further understanding is limited by insufficient genome quality and a lack of samples from typically understudied populations. Here we used hybrid long-read PromethION and short-read HiSeq sequencing to characterize the faecal microbiota of 60 Inner Mongolian individuals (n = 180 samples over three time points) who were part of a probiotic yogurt intervention trial. We present the Inner Mongolian Gut Genome catalogue, comprising 802 closed and 5,927 high-quality metagenome-assembled genomes. This approach achieved high genome continuity and substantially increased the resolution of genomic elements, including ribosomal RNA operons, metabolic gene clusters, prophages and insertion sequences. Particularly, we report the ribosomal RNA operon copy numbers for uncultured species, over 12,000 previously undescribed gut prophages and the distribution of insertion sequence elements across gut bacteria. Overall, these data provide a high-quality, large-scale resource for studying the human gut microbiota.

Lawson Criterion for Ignition Exceeded in an Inertial Fusion Experiment

For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion.

Probiotics synergized with conventional regimen in managing Parkinson's disease

Parkinson's disease (PD) is mainly managed by pharmacological therapy (e.g., Benserazide and dopamine agonists). However, prolonged use of these drugs would gradually diminish their dopaminergic effect. Gut dysbiosis was observed in some patients with PD, suggesting close association between the gut microbiome and PD. Probiotics modulate the host's gut microbiota beneficially. A 3-month randomized, double-blind, placebo-controlled clinical trial was conducted to investigate the beneficial effect of probiotic co-administration in patients with PD. Eighty-two PD patients were recruited and randomly divided into probiotic [n = 48; Bifidobacterium animalis subsp. lactis Probio-M8 (Probio-M8), Benserazide, dopamine agonists] and placebo (n = 34; placebo, Benserazide, dopamine agonists) groups. Finally, 45 and 29 patients from Probio-M8 and placebo groups provided complete fecal and serum samples for further omics analysis, respectively. The results showed that Probio-M8 co-administration conferred added benefits by improving sleep quality, alleviating anxiety, and gastrointestinal symptoms. Metagenomic analysis showed that, after the intervention, there were significantly more species-level genome bins (SGBs) of Bifidobacterium animalis, Ruminococcaceae, and Lachnospira, while less Lactobacillus fermentum and Klebsiella oxytoca in Probio-M8 group (P < 0.05). Interestingly, Lactobacillus fermentum correlated positively with the scores of UPDRS-III, HAMA, HAMD-17, and negatively with MMSE. Klebsiella oxytoca correlated negatively with feces hardness. Moreover, co-administering Probio-M8 increased SGBs involved in tryptophan degradation, gamma-aminobutyric acid, short-chain fatty acids, and secondary bile acid biosynthesis, as well as serum acetic acid and dopamine levels (P < 0.05). Taken together, Probio-M8 synergized with the conventional regimen and strengthened the clinical efficacy in managing PD, accompanied by modifications of the host's gut microbiome, gut microbial metabolic potential, and serum metabolites.

Na,K-ATPase beta-subunit is required for epithelial polarization, suppression of invasion, and cell motility

The cell adhesion molecule E-cadherin has been implicated in maintaining the polarized phenotype of epithelial cells and suppression of invasiveness and motility of carcinoma cells. Na,K-ATPase, consisting of an alpha- and beta-subunit, maintains the sodium gradient across the plasma membrane. A functional relationship between E-cadherin and Na,K-ATPase has not previously been described. We present evidence that the Na,K-ATPase plays a crucial role in E-cadherin-mediated development of epithelial polarity, and suppression of invasiveness and motility of carcinoma cells. Moloney sarcoma virus-transformed Madin-Darby canine kidney cells (MSV-MDCK) have highly reduced levels of E-cadherin and beta(1)-subunit of Na,K-ATPase. Forced expression of E-cadherin in MSV-MDCK cells did not reestablish epithelial polarity or inhibit the invasiveness and motility of these cells. In contrast, expression of E-cadherin and Na,K-ATPase beta(1)-subunit induced epithelial polarization, including the formation of tight junctions and desmosomes, abolished invasiveness, and reduced cell motility in MSV-MDCK cells. Our results suggest that E-cadherin-mediated cell-cell adhesion requires the Na,K-ATPase beta-subunit's function to induce epithelial polarization and suppress invasiveness and motility of carcinoma cells. Involvement of the beta(1)-subunit of Na,K-ATPase in the polarized phenotype of epithelial cells reveals a novel link between the structural organization and vectorial ion transport function of epithelial cells.

Reflex control of sympathetic activity during simulated ventricular tachycardia in humans

BACKGROUND

Ventricular tachyarrhythmias present a unique set of stimuli to arterial and cardiopulmonary baroreceptors by increasing cardiac filling pressures and decreasing arterial pressure. The net effect on the control of sympathetic nerve activity (SNA) in humans is unknown. The purpose of this study was to determine the relative roles of cardiopulmonary and arterial baroreceptors in controlling SNA and arterial pressure during ventricular pacing in humans.

METHODS AND RESULTS

Two experiments were performed in which SNA and hemodynamic responses to ventricular pacing were compared with nitroprusside infusion (NTP) in 12 patients and studied with and without head-up tilt or phenylephrine to normalize the stimuli to either the arterial or cardiopulmonary baroreceptors in 9 patients. In experiment 1, the slope of the relation between SNA and mean arterial pressure was greater during NTP (-4.7+/-1.4 U/mm Hg) than during ventricular pacing (-3.4+/-1.1 U/mm Hg). Comparison of NTP doses and ventricular pacing rates that produced comparable hypotension showed that SNA increased more during NTP (P=0.03). In experiment 2, normalization of arterial pressure during pacing resulted in SNA decreasing below baseline (P<0.05), whereas normalization of cardiac filling pressure resulted in a greater increase in SNA than pacing alone (212+/-35% versus 189+/-37%, P=0. 04). Conclusions--These data demonstrate that in humans arterial baroreflex control predominates in mediating sympathoexcitation during ventricular tachyarrhythmias and that cardiopulmonary baroreceptors contribute significant inhibitory modulation.

Screening anti-HIV Chinese materia medica with HIV and equine infectious anemic virus reverse transcriptase

The inhibitory activities of human immunodeficiency virus reverse transcriptase (HIV-RT) inhibitors PFA and Suramin against HIV-RT and equine infectious anemic virus reverse transcriptase (EIAV-RT) were studied in this paper. The 50% inhibitory concentration (IC50) of HIV-RT and EIAV-RT treated by PFA and Suramin were 0.2 mumol, 9.8 mumol and 17 mumol, 19.9 mumol, respectively. More than thirty Chinese medicines, including recipes, herbs, extracts of traditional materia medica and isolated compounds were tested using HIV-RT and EIAV-RT as target enzymes. It was found that 5 crude extracts such as Rhizoma Polygoni Cuspidati, and Radix Notoginseng, 7 isolated compounds like Flavone of Ramulus Visci, Flavone of Ajuga Decumbens Thumb, and Aristolochic acid, as well as the extract of the complex prescription Xiao Chai Hu Tang have shown various inhibitory actions on these two enzymes. The activities of the two enzymes were comparable, but HIV-RT was more sensitive, suggesting that HIV-RT can be used as index for the screening of anti-aids drugs.