To convert our units from milligrams to micrograms, use the following formula. There are 1, milligrams mg in a gram, and 1,, micrograms ug in a gram. That is 1, micrograms per 1 milligram. That gives us: 0. To determine amount of albumin in each tube, we now multiply the concentration of our original solution by the dilution factor of each tube. See table below. After dilution, each tube contained 1 ml of liquid. Next, 2 ml of dye was added to each tube, followed by 7 ml of water.
Thus, the final volume of each tube was 10 ml. Solution volume was a controlled variable in this experiment. We kept it the same for all tubes so we didn't have to worry that it would impact our results. Oxana Fox is a freelance writer specializing in medicine and treatment, computer software and hardware, digital photography and financial services.
She graduated from Moscow Medical College in with formal training in pediatrics. Conversion of PPM to Micromoles. How to Find Mass Percentage. Brine Vs. How to Calculate Percent Solids by Weight. As shown in Fig. Finally, 13 studies including our cohort study were included for this meta-analysis. The characteristics of these 13 studies were shown in Table 3.
Of the 12 studies other than our cohort study, 8 studies reported the absolute value of D-dimer in patients with severe disease and those with non-severe disease [ [10] , [11] , [12] , [13] , [14] , [15] , [16] , [17] ]. The odds ratio OR of severe infection in patients with D-dimer greater than 0. Characteristics of patients from 12 published studies and our cohort study included in the meta-analysis. Data of D-dimer value were shown in median IQR. For meta-analysis concerning the mean value of D-dimer, 9 studies including our cohort study were included, with patients in total.
The mean value of D-dimer of all patients was 0. Differences of mean value of D-dimer between severe and non-severe group was 0. Forest plot showing the weighted mean difference WMD of D-dimer values between patients with severe disease and those with non-severe disease. For meta-analysis concerning the odds of severe COVID, 4 studies and our cohort study were included.
Abnormal coagulation function, including elevated D-dimer, has been demonstrated to be involved in the disease progression of COVID [ 5 , 21 ]. In this study, we analyzed the association between elevated D-dimer levels and the disease severity of COVID based on the evidence from our cohort study and meta-analysis. In our retrospective cohort study, the level of D-dimer was markedly increased in patients with severe COVID, and the meta-analysis further confirmed that odds of severe COVID was associated with D-dimer greater than 0.
D-dimer assays are commonly used in clinical practice to exclude a diagnosis of deep vein thrombosis or pulmonary embolism, and elevated D-dimer indicates increased risk of abnormal blood clotting. Elevated levels of D-dimer were also found to be related with higher mortality rate of community-acquired pneumonia [ 22 ]. Patients with severe community-acquired pneumonia had significantly higher D-dimer levels, and D-dimer within normal range indicated low risk for complications [ 23 ].
Augmented activity of urokinase could cause hyperfibrinolysis, by increasing cleavage of plasminogen into the active plasmin, and finally led to diffuse alveolar damage and acute lung injury, in a mouse model of SARS-CoV disease [ 24 ].
In our cohort study, the level of coagulation function parameters, including prothrombin time, fibrinogen, fibrin ogen degradation products, and D-dimer, were found elevated in patients with severe COVID Clinical attention to venous thromboembolism risk should particularly be paid to those patients with severe COVID, who were often bedridden and presented with abnormal coagulation function [ 25 , 26 ].
Rapid deterioration was observed in cases with significantly increased D-dimer during the disease progression. In this regard, pulmonary embolism after deep vein thrombosis detachment should be considered and immediately on the alert, especially when patients presented clinical manifestations such as a rapid drop in blood pressure, sudden deterioration of oxygenation, and respiratory distress. In addition to thrombosis and pulmonary embolism, D-dimer might be a manifestation of severe virus infection.
A virus infection may develop into sepsis and induce coagulation dysfunction, which was common in serious disease progression. Moreover, the increase of D-dimer may be an indirect manifestation of inflammatory reaction, as inflammatory cytokines could cause the imbalance of coagulation and fibrinolysis in the alveoli, which may activate the fibrinolysis system, and then increase the level of D-dimer [ 27 , 28 ].
There were several limitations in our study. Firstly, a significant degree of heterogeneity and a publication bias were detected in the meta-analysis, because most of included studies were retrospective and non-randomized controlled trial.
Secondly, converting non-normally distributed statistics median and range to normally distributed statistics mean and SD may cause a bias, when evaluating the changes of D-dimer value between severe patients and non-severe patients. Thirdly, the methods of D-dimer assay were not clear in studies included in this meta-analysis. Finally, the odds of severe COVID associated with abnormal level of D-dimer, was based on univariable analysis or obtained by calculation in some studies [ 3 , [18] , [19] , [20] ].
Therefore, the bias may be inevitable. Nevertheless, our study demonstrated that the D-dimer level in patients with severe COVID was higher than that in mild cases.
Thus, the evidence that patients with elevated D-dimer levels might have a higher risk of severe infection from our cohort study and the meta-analysis, provided a timely reminder to physicians that those COVID patients with higher D-dimer should attract more attention in early time. Dai-Shi Tian and Wei Wang conceived and designed study. Chuan Qin performed statistical analyses about the cohort study, and Hai-Han Yu for the meta-analysis.
Final approval was required by all authors. Tian, to C. National Center for Biotechnology Information , U. Thromb Res. Published online Jul In other words, the abbreviation UGM may be used for other connotations not included in the list, since depending on the language or country where this abbreviation is used it may have another or other meanings. Abbreviations are used to shorten the name of something that is composed of several words in order to save letters when it is written.
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