Metabolomics analysis in pterygium tissue

Plasma Free Amino Acid Profile in HIV-Positive Cases

Background:

Increasing the sensitivity and availability of LC-MS / MS devices may provide advantages in terms of revealing the changes in metabolic pathways in HIV-positive patients and elucidating the physiopathology.

Introduction:

The aim of this study was to determine the difference in amino acid level between HIV-positive patients and healthy individuals by using LC-MS / MS, and to investigate its relationship with HIV infection.

Material and Methods:

Concentrations of 36 different amino acids and their derivatives were measured and compared in venous plasma samples from 24 HIV-positive patients and 24 healthy individuals by using the LC-MS/MS method (Shimadzu North America, Columbia, MD, USA).

Results:

HIV-positive subjects had significantly lower alanine, 1-methyl-L-histidine, valine, aspartate, cysteine, cystine, methionine, lysine, glutamine, imino acid, tyrosine, tryptophan, threonine, sarcosine, and argininosuccinic acid and significantly higher 3-methyl-L -histidine, asparagine glutamate, and carnosine levels as compared to healthy controls. No significant differences were detected in other amino acids.

Conclusion:

The significant differences in amino acid profile between HIV-positive and healthy subjects may represent an auxiliary biomarker of cellular damage in asymptomatic HIV-positive patients that may be examined in more detail in further studies. It may also provide guidance for symptomatic cases in terms of the association between symptoms, clinical manifestations and deficiency or excess of certain amino acids in the context of the complete metabolomics record of HIV-positive patients.

New Advances in Tissue Metabolomics: A Review

Metabolomics offers a hypothesis-generating approach for biomarker discovery in clinical medicine while also providing better understanding of the underlying mechanisms of chronic diseases. Clinical metabolomic studies largely rely on human biofluids (e.g., plasma, urine) as a more convenient specimen type for investigation. However, biofluids are non-organ specific reflecting complex biochemical processes throughout the body, which may complicate biochemical interpretations. For these reasons, tissue metabolomic studies enable deeper insights into aberrant metabolism occurring at the direct site of disease pathogenesis. This review highlights new advances in metabolomics for ex vivo analysis, as well as in situ imaging of tissue specimens, including diverse tissue types from animal models and human participants. Moreover, we discuss key pre-analytical and post-analytical challenges in tissue metabolomics for robust biomarker discovery with a focus on new methodological advances introduced over the past six years, including innovative clinical applications for improved screening, diagnostic testing, and therapeutic interventions for cancer.

Efficacy of bevacizumab in the treatment of pterygium: An updated meta-analysis of randomized controlled trials

Recurrence is the most common problem following pterygium surgery. Whether bevacizumab can prevent pterygium recurrence is controversial. To address this point, we carried out a meta-analysis of randomized controlled trials evaluating the efficacy and safety of bevacizumab in the treatment of pterygium. We searched the PubMed, EMBASE, Cochrane Library, Web of Science, Chinese Biomedical Literature, China National Knowledge Infrastructure, and Wan fang databases up to September 20, 2020 for relevant articles. We used the Cochrane assessment tool to evaluate the methodologic quality of the included studies, and calculated the relative risk (RR) and 95% confidence interval (CI) of the reported recurrence and complication rates. A total of 17 studies including 1124 patients with 1144 eyes were included in the meta-analysis. The combined results showed that bevacizumab significantly reduced the recurrence rate of pterygium after surgery (RR = 0.652, 95% CI: 0.504-0.845, Z = 3.24, P = 0.001) and was not significantly associated with the occurrence of postoperative complications compared to control treatments (RR = 0.832, 95% CI: 0.604-1.145, Z = 1.13, P = 0.259). A subgroup analysis showed that the rate of pterygium recurrence was significantly lower with bevacizumab than in the control group at a dose of 2.5 mg (RR = 0.47, 95% CI: 0.24-0.91) administered by subconjunctival injection (RR = 0.54, 95% CI: 0.39-0.75) after a follow-up time of ≤ 6 months (RR = 0.63, 95% CI: 0.45-0.88). Thus, bevacizumab can reduce the risk of pterygium recurrence after surgery, and does not differ from placebo or other drug treatments in terms of the risk of complications.