Simultaneous Determination of Rifamycin Antibiotics and Their Active Metabolites in Human Plasma Using UHPLC-MS/MS to Evaluate Their Impact on Target Peak Concentrations: A Short Communication.

BACKGROUND: Standard and proper antituberculosis (anti-TB) treatment is essential for patients with TB, and rifamycin antibiotics are key components of anti-TB therapy. Therapeutic drug monitoring (TDM) of rifamycin antibiotics can shorten the time to response and complete treatment of TB. Notably, antimicrobial activities of the major active metabolites of rifamycin are similar to those of their parent compounds. Thus, a rapid and simple assay was developed for simultaneous determination of rifamycin antibiotics and their major active metabolites in plasma to evaluate their impact on target peak concentrations. Here, the authors have developed and validated a method for simultaneous determination of rifamycin antibiotics and their active metabolites in human plasma using ultrahigh-performance liquid chromatography tandem mass spectrometry. METHODS: Analytical validation of the assay was performed in accordance with the bioanalytical method validation guidance for industry described by the US Food and Drug Administration and the guidelines for bioanalytical method validation described by the European Medicines Agency. RESULTS: The drug concentration quantification method for rifamycin antibiotics, including rifampicin, rifabutin, and rifapentine, and their major active metabolites was validated. Significant differences in the proportions of active metabolites in rifamycin antibiotics may affect the redefinition of their effective concentration ranges in the plasma. The method developed herein is expected to redefine the ranges of "true" effective concentrations of rifamycin antibiotics (including parent compounds and their active metabolites). CONCLUSIONS: The validated method can be successfully applied for high-throughput analysis of rifamycin antibiotics and their active metabolites for TDM in patients receiving anti-TB treatment regimens containing these antibiotics. Proportions of active metabolites in rifamycin antibiotics markedly varied among individuals. Depending on the clinical indications of patients, the therapeutic ranges for rifamycin antibiotics may be redefined.

Dynamic monitoring of serum liver function indexes in patients with COVID-19.

BACKGROUND: Some patients with the novel 2019 coronavirus disease (COVID-19) display elevated liver enzymes. Some antiviral drugs that can be used against COVID-19 are associated with a risk of hepatotoxicity. AIM: To analyze the clinical significance of the dynamic monitoring of the liver function of patients with COVID-19. METHODS: This was a retrospective study of patients diagnosed with COVID-19 in January and February 2020 at the Department of Infection, Shantou Central Hospital. The exclusion criteria for all patients were: (1) History of chronic liver disease; (2) History of kidney disease; (3) History of coronary heart disease; (4) History of malignancy; or (5) History of diabetes. The serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), γ-glutamyltransferase, and total bilirubin of patients with COVID-19 were measured on days 1, 3, 7 and 14 after admission, and compared to non-COVID-19 patents. RESULTS: Twelve patients with COVID-19 (seven men and five women) and twelve controls (eight men and four women) were included. There were one, two, and nine patients with severe, mild, and moderate COVID-19, respectively. There were no differences in age and sex between the two groups (both P > 0.05). No significant differences were found in albumin, ALT, AST, γ-glutamyltransferase, or total bilirubin between the controls and the patients with COVID-19 on day 1 of hospitalization (all P > 0.05). Serum albumin showed a decreasing trend from days 0 to 7 of hospitalization, reaching the lowest level on day 7. Total bilirubin was higher on day 3 than on day 7. ALT, AST, and γ-glutamyltransferase did not change significantly over time. The severe patient was observed to have ALT levels of 67 U/L and AST levels of 75 U/L on day 7, ALT of 71 U/L and AST of 35 U/L on day 14, and ALT of 210 U/L and AST of 123 U/L on day 21. CONCLUSION: Changes in serum liver function indicators are not obvious in the early stage of COVID-19, but clinically significant changes might be observed in severe COVID-19.

Characteristics of Renal Function in Patients Diagnosed With COVID-19: An Observational Study.

Objective: The aim of the study was to analyze the characteristics of renal function in patients diagnosed with COVID-19. Methods: In this retrospective, single-center study, we included all confirmed cases of COVID-19 in a tertiary hospital in Guangdong, China from January 20, 2020 to March 20, 2020. Blood and urine laboratory findings related to renal function were summarized, and the estimated glomerular filtration rate (eGFR) and endogenous creatinine clearance (Ccr) were also calculated to assess the renal function. Results: A total of 12 admitted hospital patients were diagnosed with COVID-19, included 3 severe cases, and 9 common cases. Serum creatinine (Scr) was not abnormally elevated in all of the patients, and blood urea nitrogen (BUN) was abnormally elevated in only 25.0% of the patients. However, compared with the recovery period, the patient's Scr and BUN increased significantly in peak of disease (p-scr = 0.002 & p-bun < 0.001). By observing the fluctuations in Scr and BUN from admission to recovery, it was found that the peak of Scr and BUN appeared within the first 14 day of the course of the disease. Urinary microprotein detection indicated that the abnormally elevated rates of urine microalbumin (UMA), α1-microglobulin (A1M), urine immunoglobulin-G (IGU), and urine transferring (TRU) standardized by urinary creatinine in peak of disease were 41.7, 41.7, 50.0, and 16.7%, respectively. The abnormal rates of the calculated eGFR and Ccr were 66.7 and 41.7%. Conclusion: Scr and BUN were generally increased during the course of COVID-19. Detection of urinary microproteins and application of multiple indicators assessment could be helpful for discovering abnormal renal function in patients with COVID-19. However, the evidence is limited due to the small sample size and observational nature. Additional studies, especially large prospective cohort studies, are required to confirm these findings.

Characterization of the transcriptomes of Atoh1-induced hair cells in the mouse cochlea.

Postnatal mammalian cochlear hair cells (HCs) can be regenerated by direct transdifferentiation or by mitotic regeneration from supporting cells through many pathways, including Atoh1, Wnt, Hedgehog and Notch signaling. However, most new HCs are immature HCs. In this study we used RNA-Seq analysis to compare the differences between the transcriptomes of Atoh1 overexpression-induced new HCs and the native HCs, and to define the factors that might help to promote the maturation of new HCs. As expected, we found Atoh1-induced new HCs had obvious HC characteristics as demonstrated by the expression of HC markers such as Pou4f3 and Myosin VIIA (Myo7a). However, Atoh1-induced new HCs had significantly lower expression of genes that are related to HC function such as Slc26a5 (Prestin), Slc17a8 and Otof. We found that genes related to HC cell differentiation and maturation (Kcnma1, Myo6, Myo7a, Grxcr1, Gfi1, Wnt5a, Fgfr1, Gfi1, Fgf8 etc.) had significantly lower expression levels in new HCs compared to native HCs. In conclusion, we found a set of genes that might regulate the differentiation and maturation of new HCs, and these genes might serve as potential new therapeutic targets for functional HC regeneration and hearing recovery.

Changes in DTI parameters in the optic tracts of macaque monkeys with monocular blindness.

For humans and non-human primates, the alteration of the visual pathway's white matter fibers after visual deprivation has been partially explored. However, the changes in the optic tracts after the transection of the optic nerve have not been well characterized. In the current study, we attempted to investigate the differences in optic tracts between normal and unilateral optic nerve transected macaque monkeys using diffusion tensor imaging (DTI). Four healthy neonatal macaque monkeys were randomly divided into 2 groups, with 2 in each group. Group A served as a control group, and Group B underwent unilateral (right eye) optic nerve transection to produce monocular blindness. Sixteen months (Group B16M) and thirty-two months (Group B32M) after optic nerve transection, diffusion tensor imaging was performed on all monkeys. Then, we compared fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD) and radial diffusivity (RD) in bilateral optic tracts between Group A and Group B and between Group B16M and Group B32M. In both Group B16M and Group B32M, when compared with normal monkeys in Group A, FA was decreased and MD, AD and RD were increased in the bilateral optic tracts of monkeys with monocular blindness. Furthermore, compared with Group B16M, FA was reduced and MD, AD, RD were more obviously increased in the bilateral optic tracts of Group B32M, and noticeable differences in MD, AD and RD were found between the left and right optic tracts in group B32M. We believe that the results of this study would be helpful in investigation of the histological abnormalities of the integrity damage, axonal degeneration and demyelination of optic tracts in macaque monkeys with monocular blindness by DTI parameters in noninvasively and quantitatively.

Simple colorimetric bacterial detection and high-throughput drug screening based on a graphene-enzyme complex.

A simple, colorimetric, sensitive, cost-effective and high-throughput system based on a positively charged graphene oxide-enzyme complex was developed for bacterial detection and drug screening.

Targeted photothermal ablation of pathogenic bacterium, Staphylococcus aureus, with nanoscale reduced graphene oxide.

Nowadays, bacterial infection is very common in the world. As a result of overusing antibiotics, several human pathogenic bacteria have become resistant to most of the clinically approved antibiotics. This has created an urgent need for the development of new methods to kill pathogenic bacteria. Here, we describe a novel method for the selective killing of pathogenic bacteria using antibody functionalized nanoscale reduced graphene oxide (NRGO). The antibody-NRGO complex exhibited little toxicity without near-infrared (NIR) irradiation. However, when irradiated with a NIR laser at a low power density (400 mW cm-2), the antibody-NRGO complex exhibited excellent photothermal properties and killed captured pathogenic bacteria specifically.

[Differential liver histopathological features of chronic HBV infection patients with normal and mildly elevated serum ALT].

To study the liver histopathological features that are distinctive between chronic hepatitis B virus (HBV) infection patients who have normal serum alanine aminotransferase (ALT)/asparatate aminotransferase (AST) and those with mildly elevated serum ALT/AST. One-hundred-and-thrity-four chronic HBV infection patients with normal serum ALT/AST and 165 chronic HBV infection patients with mildly elevated serum ALT/AST were included in the study. Liver biopsies were performed and used to assess the histological changes by hematoxylin-eosin and reticular fiber staining; mild to severe scoring for inflammation was made as grade G0-G4 and for fibrosis stage as S0-S4. HBV DNA levels were detected by fluorescent quantitative PCR. HBV serological markers were examined by chemiluminescence. The mildly elevated serum ALT/AST group had more male patients than the normal serum ALT/AST group. In the normal serum ALT/AST group, 50.0% (67/134) of the patients had moderate histological changes and only 3.0% (4/134) had severe changes (G3-4 and/or S3-4). In the mildly elevated ALT/AST group, 65.7% (174/265) of patients had moderate histological changes and 16.2% (43/265) had severe changes (G3-4 and/or S3-4). Hepatic inflammation and fibrosis were significantly more severe in the mildly elevated serum ALT/AST group than in the normal ALT/AST group (x2 = 26.386, P less than 0.01; x2 = 15.299, P less than 0.01). In the normal ALT/AST group, the severity of inflammation and fibrosis were positively correlated with age (rs = 0.620, P less than 0.01; rs = 0.347, P less than 0.01). In the mildly elevated ALT/AST group, the severity of inflammation and fibrosis were negatively correlated with age (rs = -0.807, P less than 0.01; rs = -0.557, P less than 0.01). In both groups, the severity of inflammation and fibrosis were negatively correlated with HBV DNA levels (rs = -0.215, P less than 0.01, rs = -0.527, P less than 0.01, rs = -0.951, P less than 0.01; rs = -0.715, P less than 0.01) and were not positively correlated with HBeAg. The majority of the chronic HBV infection patients with normal serum ALT/AST and those with mildly elevated serum ALT/AST had moderate liver pathological changes. All patients with low HBV DNA levels were closely followed-up, regardless of HBeAg-positive status.

[Gene copy number, mRNA transcription and protein expression of PD-1 gene in primary hepatocarcinoma patients].

OBJECTIVE: To study the gene copy number, mRNA transcription and protien expression of programmed cell death 1 (PD-1) gene in primary hepatocellular carcinoma (PHC) patients and normal control individuals (NC) who are anti-HBs positive, and to investigate the variations in PD-1 gene copy numbers and its relationship with PHC. METHODS: Real-time PCR was adopted to detect the PD-1 gene copy numbers and their mRNA expressions in peripheral blood mononuclear cells (PBMCs) from 24 samples of PHC patients and 26 of NC. Protein expression level of PD-1 on CD8+ T was analyzed by flow cytometry. RESULTS: In terms of number of PD-1 gene copy numbers, the percentage of cases of haploid (single) was 34.62% and 4.17% in PHC group and control group respectively while the percentage of cases of diploid (double) was 61.54% and 95.83% respectively. The difference between the two was statistically significant (chi2 = 7.639, P = 0.006). The rate of cases with double PD-1 gene copy numbers was found to be higher in patients with PHC than in control group. It was also found that the average expression of PD-1 mRNA was 2.35E-03 in control group and 1.23E-03 in PHC group. The expression level was significant lower in PHC group than that in control group when compared by using Mann-whitey technic (U = 153, P = 0.009). Furthermore, the frequency of PD-1 protein expression on CD8+ T cells was 3.72 +/- 0.32 in control group and 16.13 +/- 1.68 in PHC group. The level of PD-1 mRNA expression was higher in PHC and significant differences was shown between two groups (t = -7.073, P = 0.000). CONCLUSIONS: Our study suggests that the variation in PD-1 gene copy number may trigger primary hepatocellular carcinoma to HBV carriers. The relationship between the variation of PD-1 gene copy numbers and its association with primary hepatocellular carcinoma is worth further focus.

General colorimetric detection of proteins and small molecules based on cyclic enzymatic signal amplification and hairpin aptamer probe.

In this work, we developed a simple and general method for highly sensitive detection of proteins and small molecules based on cyclic enzymatic signal amplification (CESA) and hairpin aptamer probe. Our detection system consists of a hairpin aptamer probe, a linker DNA, two sets of DNA-modified AuNPs, and nicking endonuclease (NEase). In the absence of a target, the hairpin aptamer probe and linker DNA can stably coexist in solution. Then, the linker DNA can assemble two sets of DNA-modified AuNPs, inducing the aggregation of AuNPs. However, in the presence of a target, the hairpin structure of aptamer probe is opened upon interaction with the target to form an aptamer probe-target complex. Then, the probe-target complex can hybridize to the linker DNA. Upon formation of the duplex, the NEase recognizes specific nucleotide sequence and cleaves the linker DNA into two fragments. After nicking, the released probe-target complex can hybridize with another intact linker DNA and the cycle starts anew. The cleaved fragments of linker DNA are not able to assemble two sets of DNA-modified AuNPs, thus a red color of separated AuNPs can be observed. Taking advantage of the AuNPs-based sensing technique, we are able to assay the target simply by UV-vis spectroscopy and even by the naked eye. Herein, we can detect the human thrombin with a detection limit of 50 pM and adenosine triphosphate (ATP) with a detection limit of 100 nM by the naked eye. This sensitivity is about 3 orders of magnitude higher than that of traditional AuNPs-based methods without amplification. In addition, this method is general since there is no requirement of the NEase recognition site in the aptamer sequence. Furthermore, we proved that the proposed method is capable of detecting the target in complicated biological samples.

[Study on the copy numbers and mRNA expression levels of the programmed death-1 gene in chronic hepatitis B patients].

OBJECTIVE: To study the copy numbers and mRNA expression levels of the Programmed Death-1 gene in chronic hepatitis B patients and to analyze the differences of the copy numbers and mRNA expression levels of the gene in patients with different clinical outcomes. METHODS: Real time PCR was adopted to detect the PD-1 gene copy numbers and their mRNA expressions in peripheral blood mononuclear cells (PBMCs) from 27 samples from healthy donors in Control group, 31 samples from chronic asymptomatic HBV carriers (ASC, n=31), 19 samples from chronic severe hepatitis B patients (CSH, n=19) and 29 samples from Primary hepatitis B Virus-related hepatocarcinoma (PHC, n=29). The differences and relationship of copy numbers and their mRNA expression levels among those groups were compared and analyzed by adopting Chi-square test and Rank sum test. RESULTS: PD-1 gene copy number deviated from 0 copy to 3 copies among all the 106 samples. In control group, ASC group, CSH group and PHC group, the percentages of cases of haploid (single) were 37.0%, 35.5%, 26.3% and 6.9%, respectively, the percentages of cases of diploid (double) were 55.5%, 58.0%, 63.2% and 82.8%, respectively, and the percentages of cases of triploid (triple) were 3.7%, 6.5%, 10.5% and 10.3%, respectively. The percentage of cases of polyploid (diploid and triploid) in control group, ASC group, CSH group and PHC group were 59.3%, 64.5%, 73.7% and 93.1%, respectively. The different distribution of PD-1 gene copy number of polyploid was significant in total samples (x2=9.583, P<0.05). Compared with Control Group and ASC group, the percentage of cases of polyploid in PHC group was lower with the x2 equals to 8.985 and 7.215 respectively and both with P less than 0.05. The difference between the two groups was statistically significant. The mean PD-1 gene copy numbers for these four groups were 1.59+/-0.63, 1.70+/-0.52, 1.84+/-0.60 and 2.00+/-0.37 while the median were 0.002 54, 0.002 72, 0.002 55 and 0.001 33 respectively. Except the control group, there was a uptrend in the other three groups while PD-1 gene mRNA expression presented a downtrend. The mean of PD-1 gene copy numbers of 2 and their mRNA expression levels were 19.59, 32.57 and 33.22 for PHC, CSH and ASC groups among which PHC group had the lowest value, there was significant differences found in the comparison with F=5.395 and P<0.05. CONCLUSION: PD-1 gene copy numbers and their mRNA expression levels were different in chronic HBV infected patients with different transformation. It is valuable to follow up the patients with more than 1 copy number of PD-1 gene in long term.