Rapid diagnosis of disseminated Mycobacterium mucogenicum infection in formalin-fixed, paraffin-embedded specimen using next-generation sequencing: A case report.

BACKGROUND: Mycobacterium mucogenicum (M. mucogenicum) belongs to the group of rapidly growing Nontuberculous mycobacteria. This microorganism is associated with a wide spectrum of infectious diseases. Due to a low detection rate or the time required for conventional culture methodology, a rapid and broad-spectrum method is necessary to identify rare pathogens. CASE SUMMARY: A 12-year-old immunocompetent girl presented with painful masses for five months. The first mass was found in the right upper quadrant of the abdomen, and was about 1 cm × 1.5 cm in size, tough but pliable in texture, with an irregular margin and tenderness. An abscess gradually formed and ulcerated with suppuration of the mass. Three new masses appeared on the back one by one. Chest computed tomography showed patchy and streaky cloudy opacities in both lungs. Needle aspiration of the abscess was performed, but the smear and conventional culture were negative, and the pathological examination showed no pathogens. We then performed next-generation sequencing using a formalin-fixed, paraffin-embedded specimen to identify the pathogen. A significantly high abundance of M. mucogenicum was detected. The patient's abscesses gradually decreased in size, while inflammation in both lungs improved following 12-wk of treatment. No recurrence was observed four months after the end of the one-year treatment period. CONCLUSION: Next-generation sequencing is a promising tool for the rapid and accurate diagnosis of rare pathogens, even when using a formalin-fixed, paraffin-embedded specimen.

Mechanistic understanding of the different effects of Wuzhi Tablet (Schisandra sphenanthera extract) on the absorption and first-pass intestinal and hepatic metabolism of Tacrolimus (FK506).

We recently reported that the blood concentrations of Tacrolimus (FK506) in rats were markedly increased following the intake of a Chinese herbal preparation, Wuzhi Tablet (WZ, Schisandra sphenanthera extract). In order to identify the underlying mechanisms of the increase in FK506 level, we investigated the effects of WZ on the absorption and first-pass intestinal and hepatic metabolism of FK506 in vitro and in vivo. When co-administered with WZ, the AUC(0-infinity) value after oral FK506 dosing was increased by 2.1 fold, the oral bioavailability (F(oral)) was increased from 5.4% to 13.2% (p=0.0002), and the (F(abs) x F(G)) was 111.4% (p<0.01), much greater than that when FK506 was given alone. However, the F(H) was only 21.2% greater than that when FK506 was given alone, which indicates that the reduction of intestinal first-pass effect was the major cause of the increased FK506 oral bioavailability when co-administered with WZ. In the Caco-2 cell transport study, the transport ratio of FK506 with WZ extract was significantly lower than that of FK506 alone, which suggested WZ extract inhibited P-gp-mediated efflux of FK506. Furthermore, 100 microM of WZ extract almost completely inhibited FK506 metabolism in rat and human liver microsomes, indicating WZ extract potently inhibited the CYP3A-mediated metabolism of FK506. In conclusion, WZ inhibited P-gp-mediated efflux and CYP3A-mediated metabolism of FK506, and the reduction of intestinal first-pass effect by WZ was the major cause of the increased FK506 oral bioavailability.

Induction of cytochrome P450 3A by the Ginkgo biloba extract and bilobalides in human and rat primary hepatocytes.

Ginkgo biloba is one of the most popular herbal medicines in the world, due to its purported pharmacological effects, including memory-enhancing, cognition-improving, and antiplatelet effects. The study aimed to investigate the activity and expression of cytochrome P450 (CYP) 3A in human and rat primary hepatocytes treated with standardized G. biloba extract (100, 500, and 2500 ng/ml) for 72 hr, and to measure the protein expression of CYP3A in human and rat primary hepatocytes treated with bilobalide (2, 10, and 50 ng/ml) and ginkgolides B (2, 10, and 50 ng/ml). The activity of CYP3A was measured by the quantification of dehydronifedipine formation using a validated tandem liquid chromatography mass spectrometry (LC/MS/MS) method. The levels of mRNA and protein of CYP3A were determined by reverse transcription-polymerase chain reaction (RT-PCR) and Western-blotting analysis, respectively. The G. biloba extract at 100-2,500 ng/ml significantly induced the activity, protein and mRNA expression of CYP3A in a dose-dependent manner in human and rat primary hepatocytes. Bilobalide at 2-50 ng/ml significantly increased CYP3A protein expression in a dose-dependent manner in human and rat primary hepatocytes. However, ginkgolide B did not affect CYP3A protein expression in vitro. The results indicate that G. biloba extract pretreatment significantly induced the expression of CYP3A protein and mRNA and increased CYP3A activity, and there was no significant species difference between human and rat. G. biloba may cause potential interactions with substrate drugs of CYP3A. Bilobalide might play a key role in the enzyme-inducing effects of G. biloba extract. Further study is needed to identify the substances in GBE that induce CYPs in vivo, and elucidate the molecular mechanism of CYP3A induction by GBE and bilobalides.