Diagnostic accuracy and cellular origin of pleural fluid CXCR3 ligands for tuberculous pleural effusion.

BACKGROUND: Pleural biomarkers represent potential diagnostic tools for tuberculous pleural effusion (TPE) due to their advantages of low cost, short turnaround time, and less invasiveness. This study evaluated the diagnostic accuracy of two CXCR3 ligands, C-X-C motif chemokine ligand 9 (CXCL9) and CXCL11, for TPE. In addition, we investigated the cellular origins and biological roles of CXCL9 and CXCL11 in the development of TPE. METHODS: This double-blind study prospectively enrolled patients with undiagnosed pleural effusion from two centers (Hohhot and Changshu) in China. Pleural fluid on admission was obtained and levels of CXCL9 and CXCL11 were measured by an enzyme-linked immunosorbent assay (ELISA). The receiver operating characteristic (ROC) curve and the decision curve analysis (DCA) were used to evaluate their diagnostic accuracy and net benefit, respectively. THP-1 cell-derived macrophages were treated with Bacillus Calmette-Guérin (BCG), and quantitative real-time PCR (qRT-PCR) and ELISA were used to determine the mRNA and protein levels of CXCL9 and CXCL11. The chemoattractant activities of CXCL9 and CXCL11 for T helper (Th) cells were analyzed by a transwell assay. RESULTS: One hundred and fifty-three (20 TPEs and 133 non-TPEs) patients were enrolled in the Hohhot Center, and 58 (13 TPEs and 45 non-TPEs) were enrolled in the Changshu Center. In both centers, we observed increased CXCL9 and CXCL11 in TPE patients. The areas under the ROC curves (AUCs) of pleural CXCL9 and CXCL11 in the Hohhot Center were 0.70 (95 % CI: 0.55-0.85) and 0.68 (95 % CI: 0.52-0.84), respectively. In the Changshu Center, the AUCs of CXCL9 and CXCL11 were 0.96 (95 % CI: 0.92-1.00) and 0.97 (95 % CI: 0.94-1.00), respectively. The AUCs of CXCL9 and CXCL11 decreased with the advancement of age. The decision curves of CXCL9 and CXCL11 showed net benefits in both centers. CXCL9 and CXCL11 were upregulated in BCG-treated macrophages. Pleural fluid from TPE and conditioned medium from BCG-treated macrophages were chemotactic for Th cells. Anti-CXCL9 or CXCL11 neutralizing antibodies could partly block the chemotactic activity. CONCLUSIONS: Pleural CXCL9 and CXCL11 are potential diagnostic markers for TPE, but their diagnostic accuracy is compromised in elderly patients. CXCL9 and CXCL11 can promote the migration of peripheral Th cells, thus representing a therapeutic target for the treatment of TPE.

Diagnostic value of soluble biomarkers for parapneumonic pleural effusion.

Parapneumonic pleural effusion (PPE) is a common complication in patients with pneumonia. Timely and accurate diagnosis of PPE is of great value for its management. Measurement of biomarkers in circulating and pleural fluid have the advantages of easy accessibility, short turn-around time, objectiveness and low cost and thus have utility for PPE diagnosis and stratification. To date, many biomarkers have been reported to be of value for the management of PPE. Here, we review the values of pleural fluid and circulating biomarkers for the diagnosis and stratification PPE. The biomarkers discussed are C-reactive protein, procalcitonin, presepsin, soluble triggering receptor expressed on myeloid cells 1, lipopolysaccharide-binding protein, inflammatory markers, serum amyloid A, soluble urokinase plasminogen activator receptor, matrix metalloproteinases, pentraxin-3 and cell-free DNA. We found that none of the available biomarkers has adequate performance for diagnosing and stratifying PPE. Therefore, further work is needed to identify and validate novel biomarkers, and their combinations, for the management of PPE.

Pleural fluid biochemical analysis: the past, present and future.

Identifying the cause of pleural effusion is challenging for pulmonologists. Imaging, biopsy, microbiology and biochemical analyses are routinely used for diagnosing pleural effusion. Among these diagnostic tools, biochemical analyses are promising because they have the advantages of low cost, minimal invasiveness, observer independence and short turn-around time. Here, we reviewed the past, present and future of pleural fluid biochemical analysis. We reviewed the history of Light's criteria and its modifications and the current status of biomarkers for heart failure, malignant pleural effusion, tuberculosis pleural effusion and parapneumonic pleural effusion. In addition, we anticipate the future of pleural fluid biochemical analysis, including the utility of machine learning, molecular diagnosis and high-throughput technologies. Clinical Chemistry and Laboratory Medicine (CCLM) should address the topic of pleural fluid biochemical analysis in the future to promote specific knowledge in the laboratory professional community.

Age affects the diagnostic accuracy of the cancer ratio for malignant pleural effusion.

BACKGROUND AND OBJECTIVE: Cancer ratio (CR), which is defined as serum lactate dehydrogenase (LDH) to pleural fluid adenosine deaminase (ADA) ratio, has been reported to be a useful diagnostic marker for malignant pleural effusion (MPE). Whether its diagnostic accuracy is affected by age remains unknown. This study aimed to investigate the effects of age on the diagnostic accuracy of CR. METHODS: The participants in this study were from a prospective cohort (SIMPLE cohort, n = 199) and a retrospective cohort (BUFF cohort, n = 158). All participants were patients with undiagnosed pleural effusion (PE). We used receiver operating characteristic (ROC) curves to evaluate the diagnostic accuracy of CR. The effect of age on the diagnostic accuracy of CR was investigated by adjusting the upper limit of age for participant enrolment. RESULTS: Eighty-eight MPE patients were verified in the SIMPLE cohort, and thirty-five MPE patients were verified in the BUFF cohort. The AUCs of CR in the SIMPLE and BUFF cohorts were 0.60 (95% CI: 0.52-0.68) and 0.63 (95% CI: 0.54-0.71), respectively. In both cohorts, the AUCs of CR decreased with the advancement of age. CONCLUSION: Age can affect the diagnostic accuracy of CR for MPE. CR has limited diagnostic value in older patients. KEY MESSAGE: Cancer ratio is a promising diagnostic marker for malignant pleural effusion. This study revealed that its diagnostic accuracy decreased in older patients. Its diagnostic accuracy is overestimated by previous studies using tuberculosis and pneumonia patients as controls.

Diagnostic utility of pleural cell-free nucleic acids in undiagnosed pleural effusions.

Pleural effusion (PE) is a common sign caused by various disorders. Microbiology, histology and cytology are reference standards for these disorders. However, these diagnostic tools have limitations, including invasiveness, high cost, long turnaround time, and observer-dependent. Soluble biomarkers in pleural fluid (PF) are promising diagnostic tools because they are mininvasive, economical, and objective. Recent studies have revealed that some cell-free nucleic acids (e.g., DNA, mRNA, microRNA, and lncRNA) in PF are potential diagnostic markers for many disorders. Here, we review the performance of PF cell-free nucleic acids for differentiating and stratification of PE.

Diagnostic accuracy of pleural fluid lactate dehydrogenase to adenosine deaminase ratio for tuberculous pleural effusion: an analysis of two cohorts.

BACKGROUND: This study aimed to evaluate the diagnostic accuracy of pleural fluid (PF) lactate dehydrogenase (LDH) to adenosine deaminase (ADA) (LDH/ADA) ratio for tuberculous pleural effusion (TPE). Especially to explore whether the LDH/ADA ratio provides added diagnostic value to ADA. METHODS: The diagnostic accuracy of PF LDH/ADA ratio and ADA for TPE was evaluated in two cohorts, named the BUFF (Biomarkers for patients with Undiagnosed pleural eFFusion) cohort (62 with TPE and 194 with non-TPE) and the SIMPLE (a Study Investigating Markers in PLeural Effusion) cohort (33 with TPE and 177 with non-TPE). Receiver operating characteristic (ROC) curve and decision curve were used to measure the diagnostic accuracy of the PF LDH/ADA ratio. The added diagnostic value of the LDH/ADA ratio to ADA was evaluated with net reclassification improvement (NRI) and integrated discrimination improvement (IDI). RESULTS: The area under the ROC curves (AUCs) of PF ADA and LDH/ADA ratio in the BUFF cohort were 0.76 and 0.74, respectively. In the SIMPLE cohort, the AUCs of PF ADA and LDH/ADA ratio were 0.80 and 0.85, respectively. The decision curves of PF LDH/ADA and ADA were close in both the BUFF and SIMPLE cohorts. The NRI and IDI analyses did not reveal any added diagnostic value of LDH/ADA to ADA. CONCLUSIONS: PF LDH/ADA ratio has moderate diagnostic accuracy for TPE. It does not provide added diagnostic value beyond ADA. The current evidence does not support LDH/ADA ratio for diagnosing TPE.

Diagnostic accuracy of N-terminal pro-brain natriuretic peptide for Kawasaki disease: An updated systematic review and meta-analysis.

OBJECTIVE: This study aimed to investigate the diagnostic accuracy of circulating N-terminal pro-brain natriuretic peptide (NT-proBNP) for Kawasaki disease (KD). METHODS: We searched the PubMed, Web of Science and EMBASE databases to identify the eligible studies investigating the diagnostic accuracy of NT-proBNP for KD. The revised tool for the quality assessment of diagnostic accuracy studies (QUADAS-2) was used to evaluate the eligible studies' quality. A meta-analysis was performed with the bivariate model and summary receiver operating characteristic (sROC) curve. We also performed subgroup, publication bias and sensitivity analyses. RESULTS: We included 12 studies with 2173 KDs and 1909 control. The pooled sensitivity and specificity of eligible studies were 0.80 (95%CI: 0.72-0.86) and 0.81 (95%CI: 0.73-0.88), respectively. The area under sROC curve was 0.88 (95%CI: 0.84-0.90). Patient selection bias and partial verification bias were the major design weakness of the eligible studies. Sensitivity analysis revealed that the results of this meta-analysis were robust. Subgroup analysis revealed that study design, NT-proBNP assay and participants' body temperature were not the source of heterogeneity across all eligible studies. No publication bias was observed. CONCLUSION: NT-proBNP has moderate diagnostic accuracy for KD. It cannot be used for ruling in or ruling out KD when used alone.

Conjugated bilirubin as a reflex test for increased total bilirubin in apparently healthy population.

BACKGROUND: Total, unconjugated and conjugated bilirubin levels are usually ordered together in health check-up populations. The aim of this study was to investigate whether using increased total bilirubin (TBIL) as a reflex test can reduce conjugated bilirubin (CBIL) test. METHODS: Medical records of 8433 males and 4496 females who visited Shuyang People's Hospital for health check-ups were retrospectively reviewed and the fasting serum TBIL, unconjugated bilirubin (UBIL) and CBIL of patients were extracted. Reference intervals for TBIL, UBIL, CBIL and C/TBIL were established using Q2.5 to Q97.5 . The relationship between TBIL and CBIL was analyzed by Spearman's approach. Receiver operating characteristics (ROC) curve analysis was used to evaluate the predictive accuracy of TBIL for abnormal CBIL and UBIL. RESULTS: The reference intervals for TBIL in males and females were 6.9-29.3 µmol/L and 6.1-23.8 µmol/L, respectively. For CBIL, the reference intervals were 1.9-10.4 µmol/L and 1.6-8.8 µmol/L for males and females, respectively. CBIL was significantly positively correlated with TBIL, either in males (r=.75) or females (r=.73). Area under curve (AUC) of TBIL for predicting abnormal CBIL was 0.99 in both male and females. The optimal threshold of TBIL for predicting abnormal CBIL and UBIL were 21.0 µmol/L in males and 17.0 µmol/L in females. At these thresholds, <2% of subjects with abnormal CBIL or CBIL might be missed, but approximately 87% of the CBIL test could be eliminated. CONCLUSION: Conjugated bilirubin measurement is not needed for the apparently healthy males with TBIL <21.0 µmol/L or females with TBIL <17.0 µmol/L.

Predictive accuracy of serum total calcium for both critically high and critically low ionized calcium in critical illness.

BACKGROUND: The accuracy of total calcium and its corrected value for predicting critically high and critically low ionized calcium in critical illness is controversial. The aim of this study was to investigate whether the concentration of total serum calcium, either corrected for albumin or not, could predict critically high or low values in critical illness. METHODS: This report describes a retrospective study using the Medical Information Mart for Intensive Care (MIMIC) III database. Test panels that contained serum albumin, total calcium, and ionized calcium (named ATI panels) with order time intervals of less than one hour were extracted. The predictive accuracy of total calcium, either corrected for albumin or not, was assessed using receiver operating characteristic (ROC) curve analysis. RESULTS: A total of 12 118 ATIs with 103 critically low and 92 critically high ionized calcium results were extracted. The areas under ROC curves (AUCs) of corrected and uncorrected total calcium for predicting critically low ionized calcium were 0.69 (95% CI: 0.61-0.76) and 0.70 (95% CI: 0.63-0.78), respectively. For predicting critically high ionized calcium, the AUCs were 0.98 (95% CI: 0.97-1.00) and 0.97 (95% CI: 0.95-1.00), respectively. With positive predictive values (PPVs) of 0.05 and 0.10, the sensitivities (both corrected and uncorrected) were approximately 0.50 for predicting critically low ionized calcium and 0.95 for predicting critically high ionized calcium. CONCLUSIONS: Total calcium, either corrected for albumin or not, is not a reliable test to predict critically low ionized calcium in critical illness. Total calcium's predictive accuracy for critically high ionized calcium is high.

Neutrophil to lymphocyte ratio (NLR) and platelet to lymphocyte ratio (PLR) were useful markers in assessment of inflammatory response and disease activity in SLE patients.

OBJECTIVE: Although there have been extensive investigations on neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR) and mean platelet volume (MPV) in many diseases, their roles in systemic lupus erythematosus (SLE) remain unclear. The purpose of the present study was to evaluate NLR, PLR, and MPV levels in adult SLE patients and explore their clinical significance. METHODS: A retrospective study involving 154 adult SLE patients and 151 healthy controls was performed. All clinical characteristics of the SLE patients were extracted from their medical records. NLR, PLR, and MPV levels between SLE patients and healthy controls were compared, and correlations between these indexes and clinical characteristics were analyzed. RESULTS: Increased NLR, PLR, and MPV were observed in SLE patients. NLR was positively correlated with C-reaction protein (r = 0.509, p < 0.01), erythrocyte sedimentation rate (r = 0.610, p < 0.01), and SLE Disease Activity Index (SLEDAI) scores (r = 0.471, p < 0.01). PLR was positively correlated with SLEDAI scores (r = 0.44, p < 0.01). SLE patients with nephritis had higher NLR and PLR levels than those without nephritis (p < 0.01, p = 0.03). In addition, an NLR level of 2.065 was determined as predictive cut-off value of SLE (sensitivity 74.7%, specificity 77.5%, AUC = 0.828). Multiple regression analysis suggested that NLR was independently associated with SLE disease activity. CONCLUSIONS: NLR and PLR could reflect inflammatory response and disease activity in SLE patients.

Computational insights into the inhibition and destabilization of morin on the oligomer of full-length human islet amyloid polypeptide.

The aggregation of human islet amyloid polypeptide (hIAPP) is closely related with the occurrence of type 2 diabetes (T2D). Natural flavonoid morin was confirmed to not only inhibit the amyloid formation of hIAPP, but disaggregate its preformed amyloid fibrils. In this study, with the goal of elucidating the molecular mechanism of inhibition and destabilization of morin on the full-length hIAPP(1-37) oligomer, molecular dynamics simulations were performed for hIAPP(1-37) pentamer in the presence and absence of morin. The obtained results show that during the protein-inhibitor interaction, morin can notably alter the structural properties of hIAPP(1-37) pentamer, such as morphology, solvent accessible surface area and secondary structure. Moreover, we identified three possible binding sites of morin on hIAPP, all of which located near the amyloidogenic region of this protein. From the binding free energy calculations, we found that Site II was the most possible one. Further conformational analysis together with energy decomposition showed that the residues His18, Phe23 and Ile26 play a key role in the binding with morin by hydrogen bond, π-π and hydrophobic interactions. The proposal of the theoretical mechanism of morin against hIAPP aggregation will provide valuable information for the development of new drugs to inhibit hIAPP aggregation.

Diagnostic value of total plasma lysophosphatidic acid in ovarian cancer: a meta-analysis.

OBJECTIVE: This study aimed to assess the diagnostic value of lysophosphatidic acid (LPA) in ovarian cancer. METHODS: A systematic review of related studies was performed; sensitivity, specificity, and other measures about the accuracy of serum LPA in the diagnosis of ovarian cancer were pooled using random-effects models. Summary receiver operating characteristic curve analysis was used to summarize the overall test performance. RESULTS: Six studies involving 363 patients with ovarian cancer and 273 healthy control women met the inclusion criteria. The summary estimates for LPA in diagnosing ovarian cancer in the included studies were as follows: sensitivity, 0.94 [95% confidence interval (CI), 0.91-0.96]; specificity, 0.88 (95% CI, 0.83-0.91); and diagnostic odds ratio, 141.59 (95% CI, 52.1-384.63). The area under the curve and Q value for summary receiver operating characteristic curves were 0.97 and 0.92, respectively. CONCLUSIONS: The LPA assay showed high accuracy and sensitivity for the diagnosis of ovarian cancer. The present study was limited by the small number of available studies and sample size; therefore, additional studies with a better design and larger samples are needed to further assess the diagnostic accuracy of LPA.

Neutrophil- and platelet-to-lymphocyte ratios are correlated with disease activity in rheumatoid arthritis.

BACKGROUND: Both neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) are reported to be increased in various inflammation-related diseases, but their clinical significance in rheumatoid arthritis (RA) remains unclear. The aim of the present study was to explore whether NLR and PLR were candidate indices for RA disease-activity assessment. METHODS: The medical records of 128 RA patients and 78 healthy individuals were retrospectively reviewed. Correlations of NLR and PLR with the disease activity of RA were evaluated. RESULTS: NLR and PLR were increased significantly in RA patients. NLR was significantly positively correlated with C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and Disease-Activity Score including 28 joints (DAS28) in RA patients, while PLR was positively correlated with CRP and DAS28, but not with ESR. CONCLUSIONS: Both NLR and PLR values may prove to be potential indices for RA disease-activity assessment.

[Attenuated Total Reflection Infrared Spectroscopy for Degradation Profile of High Density Polyethylene after Weathering Aging].

High density polyethylene (HDPE) was widely used as rotational packaging case in the material reserve field. The chemical changes of HDPE, exposed to particular climatic conditions of tropic marine atmosphere for one year-long in Wanning Hainan, were elucidated by the attenuated total reflection infrared spectroscopy (ATR-FTIR). The structural changes were studied qualitatively, mainly from the polymeric chain breaking, branching and oxidation to distinguish the degradation profile. The variations of crystallinity & carbonyl index were also studied quantitatively according to the characteristic peaks intensity & area ratio. Finally, the relationships between structural changes and mechanical properties were investigated. The results showed that the polymeric chain breaking & branching play a leading role before 3 months in the aging progress. Then oxidation phenomena gradually takes place during 3-6 months. The chain branching & oxidation were predominant factors after 6 months. Nine months later, the oxidation was saturated gradually. Furthermore, the aging process is positively correlated to the temperature and irradiation. After 12 months aging, the carbonyl index increased by 112 times and crystallinity was 10% higher than before. The tensile/bending modulus deceased faster than tensile/bending strength of HDPE. The linear degree of tensile modulus and carbonyl index was 0.97. The degree of linearity of tensile strength and crystallinity calculated by feature bands (720-730 cm(-1)) was 0.96. It showed that the mechanical properties of HDPE can be speculated from the structural changes by ATR-FTIR.

Pleural fluid carbohydrate antigen 72-4 and malignant pleural effusion: a diagnostic test accuracy study.

BACKGROUND: The prognosis of malignant pleural effusion (MPE) is poor. A timely and accurate diagnosis is the prerequisite for managing MPE patients. Carbohydrate antigen 72-4 (CA72-4) is a diagnostic tool for MPE. OBJECTIVE: We aimed to evaluate the diagnostic accuracy of pleural fluid CA72-4 for MPE. DESIGN: A prospective, preregistered, and double-blind diagnostic test accuracy study. METHODS: We prospectively enrolled participants with undiagnosed pleural effusions from two centers in China (Hohhot and Changshu). CA72-4 concentration in pleural fluid was measured by electrochemiluminescence. Its diagnostic accuracy for MPE was evaluated by a receiver operating characteristic (ROC) curve. The net benefit of CA72-4 was determined by a decision curve analysis (DCA). RESULTS: In all, 153 participants were enrolled in the Hohhot cohort, and 58 were enrolled in the Changshu cohort. In both cohorts, MPE patients had significantly higher CA72-4 levels than benign pleural effusion (BPE) patients. At a cutoff value of 8 U/mL, pleural fluid CA72-4 had a sensitivity, specificity, and area under the ROC curve (AUC) of 0.46, 1.00, and 0.79, respectively, in the Hohhot cohort. In the Changshu cohort, CA72-4 had a sensitivity, specificity, and AUC of 0.27, 0.94, and 0.86, respectively. DCA revealed the relatively high net benefit of CA72-4 determination. In patients with negative cytology, the AUC of CA72-4 was 0.67. CONCLUSION: Pleural fluid CA72-4 helps differentiate MPE and BPE in patients with undiagnosed pleural effusions.

Pleural carbohydrate antigen 50 and malignant pleural effusion: a prospective, double-blind diagnostic accuracy test.

Background: Serum carbohydrate antigen 50 (CA50) is an auxiliary diagnostic marker for various solid tumors, but it remains unclear whether CA50 in pleural fluid can assist in the diagnosis of malignant pleural effusion (MPE). This study aimed to evaluate the diagnostic accuracy of pleural fluid CA50 for MPE in pleural effusion patients with undetermined causes. Methods: This study prospectively recruited pleural effusion patients with undetermined causes who visited the Affiliated Hospital of Inner Mongolia Medical University between September 2018 and July 2021. We measured pleural fluid CA50 level with an electrochemiluminescence assay. We analyzed the diagnostic accuracy of CA50 and carcinoembryonic antigen (CEA) for MPE with the receiver operating characteristic (ROC) curve. The net benefits of CA50 and CEA were analyzed using the decision curve analysis (DCA). Results: We enrolled 66 MPEs and 87 benign pleural effusions (BPEs). MPE patients had significantly higher CA50 and CEA than BPE patients. The area under the ROC curve (AUC) of CA50 was 0.72 (95% CI: 0.63-0.80). CA50 had a sensitivity of 0.30 (95% CI: 0.19-0.41) and a specificity of 1.00 (95% CI: 1.00-1.00) at the threshold of 15 IU/mL. The decision curve of CA50 was above the reference line at the calculated risk probability of between 0.30 and 1.00. Venn diagram indicated that some patients with low CEA (<50 or <150 ng/mL) and/or negative cytology can be identified by positive CA50 (>15 IU/mL). Conclusions: Pleural fluid CA50 has moderate accuracy and net benefit for detecting MPE. CA50 >15 IU/mL can be used to diagnose MPE. The combination of CA50 and CEA improves the diagnostic sensitivity for MPE.

Apolipoprotein E in patients with undiagnosed pleural effusion: a prospective diagnostic test accuracy study.

INTRODUCTION: Pleural effusion is common in clinical practice, and its differential diagnosis remains challenging for clinicians. This study investigates the diagnostic value of apolipoprotein E (apoE) in patients with undetermined pleural effusion. METHODS: This prospective, double-blind study enrolled 152 patients with undiagnosed pleural effusion. Their pleural fluid apoE levels were measured, and a receiver operating characteristics (ROC) curve was used to evaluate the diagnostic accuracy of apoE. Decision curve analysis (DCA) was used to assess apoE's net benefit. Subgroup analyses were performed to investigate the effect of age on the diagnostic accuracy of apoE. RESULTS: Among the included participants, 23 had heart failure (HF). HF patients had the lowest apoE level among pleural effusion patients. The area under the curve (AUC) of apoE for HF was 0.79 (95%CI: 0.69-0.89). At the threshold of 40 mg/L, the sensitivity and specificity of apoE were 0.96 (95%CI: 0.87-1.00) and 0.33 (95%CI: 0.25-0.42), respectively. The decision curve for apoE was above reference lines. The AUC of apoE decreased in older patients. CONCLUSION: Pleural fluid apoE has moderate diagnostic value for HF and has net benefits in patients with undiagnosed pleural effusion. The diagnostic accuracy of apoE decreases with age.

Capillary electrophoresis applied to screening of trypsin inhibitors using microreactor with trypsin immobilized by glutaraldehyde.

An efficient and durable online capillary immobilized trypsin microreactor was successfully established to study the enzyme kinetics of trypsin and screen its inhibitors from natural extracts through capillary electrophoresis (CE). In this procedure, trypsin was immobilized on the inner wall at the inlet of the capillary treated with 3-aminopropyltrimethoxy silane (3-APTES), producing a trypsin microreactor via cross-linking of glutaraldehyde with 3-APTES and trypsin. The rest of the capillary was selected as a channel for separating the generated product and unreacted substrate of the trypsin enzymatic reaction. The parameters affecting the separation efficiency and activity of immobilized trypsin were evaluated systematically. The optimized conditions were as follows: 50 mM Tris-HCl (pH 8.0), 15 kV, 37 °C, 10 mM substrate, incubation for 2 min. Under optimal conditions, separation of the product and substrate was achieved through CE within 3.5 min. The obtained results of Michaelis constant, inhibition kinetics constant, and half-maximal inhibitory concentration for the immobilized trypsin using benzamidine hydrochloride hydrate as a model inhibitor were 1.56, 1.79 and 3.98 mM, respectively. The proposed method was successfully applied for screening of trypsin inhibitors from 19 kinds of natural extracts.

Red blood cell distribution width is a potential prognostic index for liver disease.

BACKGROUND: Red blood cell distribution width (RDW) is increased in liver disease. Its clinical significance, however, remains largely unknown. The aim of this study was to identify whether RDW was a prognostic index for liver disease. METHODS: We studied, retrospectively, 33 patients with non-cirrhotic HBV chronic hepatitis, 125 patients with liver cirrhosis after HBV infection, 81 newly diagnosed primary hepatocellular carcinoma (pHCC) patients, 17 alcoholic liver cirrhosis patients and 42 patients with primary biliary cirrhosis (PBC). Sixty-six healthy individuals represented the control cohort. We analyzed the relationship between RDW on admission and clinical features. The association between RDW and hospitalization outcome was estimated by receiver operating curve (ROC) analysis and a multivariable logistic regression model. RESULTS: Increased RDW was observed in liver disease patients. RDW was positively correlated with serum bilirubin and creatinine levels, prothrombin time, and negatively correlated with platelet counts and serum albumin concentration. A subgroup analysis, considering the different etiologies, revealed similar findings. Among the patients with liver cirrhosis, RDW increased with worsening of Child-Pugh grade. In patients with PBC, RDW positively correlated with Mayo risk score. Increased RDW was associated with worse hospital outcome, as shown by the AUC [95% confidence interval (CI)] of 0.76 (0.67-0.84). RDW above 15.15% was independently associated with poor hospital outcome after adjustment for serum bilirubin, platelet count, prothrombin time, albumin and age, with the odds ratio (95% CI) of 13.29 (1.67-105.68). CONCLUSIONS: RDW is a potential prognostic index for liver disease.