ABSTRACT
The SARS-CoV-2 main protease is an essential molecule for viral replication and is often targeted by medications to treat the infection. In this study, we investigated the possible inhibitory action of endogenous quinones on the enzyme. Recombinant SARS-CoV-2 main protease was exposed to tryptamine-4,5-dione (TD) or quinone from 5-hydroxyindoleacetic acid (Q5HIAA). As a result, the protease activity was considerably decreased in a dose-dependent manner. The IC50 values of the quinones toward the enzyme were approximately 0.28 µM (TD) and 0.49 µM (Q5HIAA). Blot analyses using specific antibodies to quinone-modified proteins revealed that quinones were adducted to the enzyme at concentrations as low as 0.12 µM. Intact mass analyses showed that one or two quinone molecules were covalently adducted onto the main protease. Chymotrypsin-digested main protease analyses revealed that the quinones bind to thiol residues at the enzyme's active site. When TD or Q5HIAA were exposed to cultured cells expressing the viral enzyme, quinone-modified enzyme was identified in the cell lysate, suggesting that even extracellularly generated quinones could react with the viral enzyme expressed in an infected cell. Thus, these endogenous quinones could act as inhibitors of the viral enzyme.
Subject(s)
COVID-19 , Quinones , Humans , Quinones/chemistry , Serotonin/pharmacology , SARS-CoV-2 , Coronavirus 3C Proteases , Cells, Cultured , Protease InhibitorsABSTRACT
PURPOSE: We used a lateral or posterior approach to perform retroperitoneoscopic adrenalectomy for adrenal tumors and compared the results to determine which approach is more advantageous. PATIENTS AND METHODS: We removed 42 adrenal tumors from 42 patients by retroperitoneoscopic surgery. We used the posterior approach in 17 cases and the lateral approach in 25 cases. We compared the operating time, complications, and surgical advantages for the two approaches. RESULTS: The mean operating time was significantly shorter with the lateral approach, 141 +/- 64 minutes v 225 +/- 88 minutes for the posterior approach (P = 0.0019), which we believe reflects the technical advantages of the lateral approach. Complications included one case of pneumothorax and an instance of pulmonary edema in a patient with chronic renal failure using the lateral approach and one occurrence each of pneumothorax and bleeding using the posterior approach. Retroperitoneoscopic adrenalectomy could not be performed in 1 of 25 cases (4.0%) using the lateral approach and in 3 of 17 cases (17.6%) using the posterior approach. CONCLUSION: Our series suggests that the lateral approach is preferable to the posterior approach for retroperitoneoscopic adrenalectomy.
Subject(s)
Adrenal Gland Neoplasms/surgery , Adrenalectomy/methods , Laparoscopy , Adrenalectomy/adverse effects , Adult , Aged , Female , Humans , Laparoscopy/adverse effects , Male , Middle Aged , Retroperitoneal Space , Treatment OutcomeABSTRACT
The objective of this study was to develop a new simplified method using thin-layer chromatography (TLC) for determining isoniazid (INH) compliance in patients receiving antituberculosis chemotherapy. TLC was performed on silica gel plates using a standard solution of INH and acetylisoniazid (AcINH) and ethyl acetate-methanol (70:30 v/v) as the developing solvent. The spots of compound were detected by iodine. In the human study, fractional urine samples were collected over 24 hours from 4 healthy human subjects genotyped for NAT2* and to whom 400 mg of INH were administered orally. These samples were used for TLC analysis. The results of TLC were compared with those of high-performance liquid chromatography (HPLC). This method indicated good separation between INH and AcINH in standard solutions. The detection limits for INH and AcINH (applied volume; 20 microl of standard solution) were 2.2 nmole and 5 nmole, respectively, as detected by iodine. In the human study, the INH spot in urine was not detected on the TLC plate, except in one sample over the 0- to 4-hour period from 1 volunteer. However, the AcINH spot was detected in all urine samples from all volunteers. The total experimental time from application of the urine sample to analysis on TLC was 30 minutes. The results suggest that this method for detecting AcINH on TLC is an excellent, convenient, and simple method for determining INH compliance in patients receiving standard antituberculosis chemotherapy regimen or INH preventative therapy, regardless of the patient's NAT2* genotype.
