ABSTRACT
Background: Vitamin D may play a vital role in preventing the multi-system consequences of COVID-19 infections. The aim of this study is to evaluate the potential association between mean serum levels of vitamin D and COVID-19 and its correlation with severity and mortality. Results: A case-control study conducted on 80 Egyptian patients admitted at Ain Shams University designated hospitals, Cairo, Egypt, from March 2021 to September 2021. Regarding the laboratory investigations, we found that COVID-19 cases have significantly lower lymphocytic counts than controls. Regarding vitamin D, this study showed a statistically significant positive correlation between vitamin D and lymphocytes, and there were statistically significant negative correlations between vitamin D, neutrophil-lymphocyte ratio, C-reactive protein, blood urea nitrogen, serum creatinine, aspartate aminotransferase, alanine aminotransferase, ferritin, lactate dehydrogenase, and D-dimer. Conclusion: This study confirms that vitamin D deficiency is associated with the severity of COVID-19 clinically and laboratory.
ABSTRACT
BACKGROUND: Stem cell autophagy disruption is responsible for the development of hepatocellular carcinoma (HCC). Many non-coding RNAs are linked to the activation and inhibition of certain genes. The SQSTM1 gene controls stem cell autophagy as shown in previous studies. The upregulation of SQSTM1 is associated with the inhibition of autophagy in cancerous stem cells in patients with HCC. AIM: To determine whether serum microRNA, hsa-miR-519d, is linked to SQSTM1 gene and whether they could be used as diagnostic biomarkers for early-stage HCC. METHODS: In silico analysis was performed to determine the most correlated genes of autophagy with microRNAs. SQSTM1 and hsa-miR-519d were validated through this pilot clinical study. This study included 50 Egyptian participants, who were classified into three subgroups: Group 1 included 34 patients with early-stage HCC, Group 2 included 11 patients with chronic liver disease, and Group 3 (control) included 5 healthy subjects. All patients were subjected to full laboratory investigations, including viral markers and alpha-fetoprotein (AFP), abdominal ultrasound, and clinical assessment with the Child-Pugh score calculation. Besides, the patients with HCC underwent triphasic computed tomography with contrast to diagnose and determine the tumor site, size, and number. Quantitative real-time polymerase chain reaction was used to assess hsa-miR-519d-3p and SQSTM1 in the serum of all the study participants. RESULTS: Hsa-miR-519d-3p was significantly upregulated in patients with HCC compared with those with chronic liver disease and healthy subjects with an area under the curve (AUC) of 0.939, with cutoff value 8.34, sensitivity of 91.2%, and specificity of 81.8%. SQSTM1 was upregulated with an AUC of 0.995, with cutoff value 7.89, sensitivity of 97.1%, and specificity of 100%. AFP significantly increased in patients with HCC with an AUC of 0.794, with cutoff value 7.30 ng/mL, sensitivity of 76.5%, and specificity of 72.7%. CONCLUSION: This study is the first to show a direct relation between SQSTM1 and hsa-miR-519d-3p; they are both upregulated in HCC. Thus, they could be used as surrogate diagnostic markers for stem cell autophagy disturbance in early-stage HCC.
ABSTRACT
The present work describes cloning, expression, purification, characterization, and mutation of Plasmodium falciparum guanylate kinase (PlasmoDB ID PFI1420w). Amino-acid sequence alignment revealed important differences especially in K42-V51, Y73-A77, and F100-L110, which include residues important for kinase activity, and at helix 3, which is important for domain movements. The catalytic efficiency for dGMP was 22-fold lower than that for GMP, whose value is the lowest among known guanylate kinases. dGMP was found to a competitive inhibitor for GMP with K(i)=0.148 mM and a mixed-type inhibitor with regard to ATP with measured K(i)=0.4 mM. The specificity constant (K(cat)/K(m)) of the four examined mutants varied for natural substrate GMP/dGMP, indicating the involvement of different mechanisms in substrate recognition and subsequent loop-domain movement. These results show that P. falciparum guanylate kinase is structurally and biochemically distinct from other guanylate kinases and could be a possible target in drug development.
