Derangement in Nicotinamide Adenine Dinucleotide Metabolism is Observed During Acute Kidney Injury Among Male Agricultural Workers at Risk for Mesoamerican Nephropathy.

Introduction: Mesoamerican nephropathy (MeN) is a chronic kidney disease (CKD) which may be caused by recurrent acute kidney injury (AKI). We investigated urinary quinolinate-to-tryptophan ratio (Q/T), a validated marker of nicotinamide adenine dinucleotide (NAD+) biosynthesis that is elevated during ischemic and inflammatory AKI, in a sugarcane worker population in Nicaragua with high rates of MeN. Methods: Among 693 male sugarcane workers studied, we identified 45 who developed AKI during the harvest season. We matched them 1:1 based on age and job category with 2 comparison groups: (i) "no kidney injury," active sugarcane workers with serum creatinine (sCr) <1.1 mg/dl; and (ii) "CKD," individuals no longer working in sugarcane due to their CKD, who had additional 1:1 matching for sCr. We measured urine metabolites using liquid chromatography coupled tandem mass spectrometry (LC-MS/MS) and compared Q/T and other metabolic features between the AKI and comparison groups. Results: Urine Q/T was significantly higher in workers with AKI than in those with no kidney injury (median interquartile Range [IQR]: 0.104 [0.074-0.167] vs. 0.060 [0.045-0.091], P < 0.0001) and marginally higher than in workers with CKD (0.086 [0.063-0.142], P = 0.059). Urine levels of the NAD+ precursor nicotinamide were lower in the AKI group than in comparison groups. Conclusion: Workers at risk for MeN who develop AKI demonstrate features of impaired NAD+ biosynthesis, thereby providing new insights into the metabolic mechanisms of injury in this population. Therapeutic use of oral nicotinamide, which may ameliorate NAD+ biosynthetic derangement and fortify against kidney injury, should be investigated to prevent AKI in this setting.

Evaluation of a Novel Ablative 1940 nm Pulsed Laser for Skin Rejuvenation.

BACKGROUND: Skin rejuvenation is a widely sought-after goal, prompting advancements in laser technology for noninvasive and effective treatments. Ablative lasers, in particular, have evolved to address diverse skin concerns, with fractional ablative lasers offering better-tolerated outcomes. The introduction of a novel ablative Thulium pulsed laser, based on Thulium-doped Yttrium aluminum Perovskite (Tm:YAP) crystal, delivers precise and controlled skin rejuvenation by allowing customization of ablative microcolumns. METHODS: A pilot in vivo study was conducted on the abdominal skin of a live female pig. Using the Laser Team Medical (LTM) prototype laser, treatments were administered with varying coagulation settings (minimal and maximum) and energies (32, 80, 120, and 160 mJ per microcolumn). Biopsies were harvested, fixed, and stained for subsequent analysis. The penetration depth and width of the microcolumns were evaluated. RESULTS: Low coagulation settings produced ablative microcolumns with thermal affected zones of 160 µm width, while high coagulation settings resulted in wider zones of 400-530 µm. The ablation cavities' width was estimated to be less than 100 µm in both settings. The novel 1940 nm pulsed laser demonstrated superior microcolumn properties, offering potential advantages such as shorter downtime and increased efficacy compared to existing fractional ablative lasers. CONCLUSION: This study presents encouraging preliminary results regarding the efficacy and safety of the first ablative 1940 nm pulsed laser. The results show ablative microcolumns thinner than the counterpart devices, showing the device safety and potential higher efficacy along with short downtime. The LTM novel ablative 1940 nm pulsed laser holds immense potential for enhancing skin rejuvenation treatments due to its superior microcolumns properties. The versatility of this laser can open new treatment procedures and may extend to different areas of dermatology.