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Laser lithotripsy mechanisms can cause the chemical decomposition of stone components and the emergence of different end products. However, the potentially toxic end products formed during thulium fiber laser (TFL) lithotripsy of cystine stones have not been sufficiently investigated. The aim of our in vitro study is to analyze the chemical content of the gas products formed during the fragmentation of cystine stone with TFL. Human renal calculi consisting of 100% pure cystine, calcium oxalate monohydrate, or uric acid were fragmented separately with TFL in experimental setups and observed for gas release. After the lithotripsy, only the cystine stones showed gas formation. Gas chromatography-mass spectrometry was used to analyze the gas qualitatively, and scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX) and X-ray diffraction was used to examine the dried cystine stone fragments. Fragmentation of the cystine stones released free cystine, sulfur, hydrogen sulfide, and carbon disulfide gas. The SEM-EDX and X-ray diffraction analyses revealed that the free cystine in the dried fragments contained 43.1% oxygen, 28.7% sulfur, 16.1% nitrogen, and 12.1% carbon atoms according to atomic weight. The detection of potentially toxic gases after lithotripsy of cystine stones with TFL indicates a risk of in vivo production. Awareness needs to be increased among healthcare professionals to prevent potential inhalation and systemic toxicity for patients and operating room personnel during TFL lithotripsy of cystine stones. [ABSTRACT FROM AUTHOR]

Purpose: We aimed to evaluate the diagnostic sensitivity and specificity of the miRNA-371a-3p for the primary diagnosis of germ cell tumors (GCT) and to investigate its relationship with pathological factors and clinical stage in the Turkish population. Materials and Methods: In this prospective study, a total of 60 patients with GCTs, and 40 healthy male controls were examined for serum levels of miRNA-371a-3p before orchiectomy and again two weeks after surgery. The miRNA-371a-3p, alpha-fetoprotein (AFP), and beta-human chorionic gonadotropin (bHCG) levels in the preoperative and postoperative periods were compared at different clinical stages. Receiver operating characteristics curve analyses were performed to determine the sensitivity and specificity of miRNA-371a-3p. Clinical and pathological factors such as clinical stage (CS), tumor size, histology, rete testis invasion, and lymphovascular invasion, potentially impacting miRNA-371a-3p expression levels (relative quantity, RQ), were evaluated statistically. Results: The sensitivity of miR-371a-3p in GCT patients was 98.3%, and the specificity was 95% (AUC = 0.997 [95%Cl:0.99–1], p < .001). miR-371a-3p expression was not detected in two patients with teratoma. The median miR-371a-3p RQ was 489 times in GCT and 2.2 times in the Control group (p < .001). In the postoperative period, there was a significant decrease in AFP and bHCG levels in all CS-1 (p = .01) and 30% of the other CS (p = .3). Throughout this time there was a decrease of 19 times at the miR-371a-3p RQ in CS-1(p < .001) and 1.6 times in the other CS (p < .001). The miR-371a-3p RQs were correlated with tumor size and CS. Conclusion: The miR-371a-3p seems to have higher diagnostic accuracy than classical serum tumor markers in GCT. [ABSTRACT FROM AUTHOR]