Clinical evaluation of droplet digital pcr for suspected ascites infection in patients with liver cirrhosis.

BACKGROUND: Droplet digital PCR (ddPCR) is increasingly used in diagnosing clinical pathogens, but its effectiveness in cirrhosis patients with suspected ascites infection remains uncertain. METHODS: The diagnostic performance of ddPCR was assessed in 305 ascites samples, utilizing culture and clinical composite standards. The quantitative value and potential clinical impact of ddPCR were further analyzed in patients with spontaneous bacterial peritonitis. RESULTS: With culture standards, ddPCR demonstrated a sensitivity of 86.5% and specificity of 83.2% for bacterial or fungal detection. After adjustment of clinical composite criteria, specificity increased to 96.4%. Better diagnostic performance for all types of targeted pathogens, particularly fungi, was observed with ddPCR compared to culture, and more polymicrobial infections were detected (30.4% versus 5.7%, p < 0.001). Pathogen loads detected by ddPCR correlated with white blood cell count in ascites and blood, as well as polymorphonuclear cell (PMN) count in ascites, reflecting infection status rapidly. A positive clinical impact of 55.8% (43/77) was observed for ddPCR, which was more significant among patients with PMN count ≤ 250/mm3 in terms of medication adjustment and new diagnosis. ddPCR results for fungal detection were confirmed by clinical symptoms and other microbiological tests, which could guide antifungal therapy and reduce the risk of short-term mortality. CONCLUSIONS: ddPCR, with appropriate panel design, has advantages in pathogen detection and clinical management of ascites infection, especially for patients with fungal and polymicrobial infections. Patients with atypical spontaneous bacterial peritonitis benefited more from ddPCR.

Clinical Evaluation of Metagenomic Next-Generation Sequencing Method for the Diagnosis of Suspected Ascitic Infection in Patients with Liver Cirrhosis in a Clinical Laboratory.

Metagenomic next-generation sequencing (mNGS), mostly carried out in independent clinical laboratories, has been increasingly applied in clinical pathogen diagnosis. We aimed to explore the feasibility of mNGS in clinical laboratories and analyze its potential in the diagnosis of infectious ascites. Two reference panels composed of 12 strains commonly appearing in peritonitis were constructed to evaluate the performance metrics based on in-house mNGS protocols. The mNGS clinical detection value was analyzed in 211 ascitic samples and compared with culture and composite standards. Finally, eight patients with cirrhosis were prospectively enrolled to verify the clinical value of mNGS in peritoneal infection diagnosis. The mNGS analytical performance showed that the assay had great linearity, specificity, stability, interference, and limits of detection of 33 to 828 CFU/mL. The sensitivity and specificity of mNGS for bacterial or fungal detection using culture standards were 84.2% and 82.0%, respectively. After adjustment using digital PCR and clinical judgment, the sensitivity and specificity increased to 87.2% and 90.1%, respectively. Compared with culture, mNGS detected a broad range of pathogens and more polymicrobial infections (49% versus 9%, P < 0.05). The pathogen results were obtained within 24 h using mNGS in eight prospective cases, which effectively guided antibiotics therapy. mNGS testing in clinical laboratories affiliated with a hospital has certain advantages. It has unique superiority in pathogens detection, particularly in patients with polymicrobial infections. However, considering spectrum characteristics and test cost, pertinent pathogen panels should be developed in clinical practice. IMPORTANCE This study established and evaluated a complete metagenomics next-generation sequencing assay to improve the diagnosis of suspected ascitic infection in a clinical laboratory affiliated with a hospital. The assay is superior to traditional culture testing and will aid in the early and accurate identification of pathogens, particularly in patients with polymicrobial infections. This assay is also essential for precision therapy and can reduce the incidence of drug resistance stemming from irrational use of antibiotics.

Liver stiffness measurement is a potent predictor of histological fibrosis regression after hepatitis C virus clearance.

BACKGROUND: Most of the studies on fibrosis regression prediction were based on noninvasive fibrosis markers and differ greatly. The 'Beijing fibrosis classification' can use histological results to classify fibrosis into progressive or 'nonprogressive' according to fibrotic septal morphology. We use this standard which served as the gold standard in order to find fibrosis regression predictors. AIM: To study the predictors of fibrosis regression after hepatitis C virus clearance according to histological fibrosis staging by the 'Beijing fibrosis classification'. MATERIALS AND METHODS: This was a prospective cohort study. A total of 68 patients with advanced liver fibrosis or compensated cirrhosis who achieved sustained virological response were enrolled. Patients with the Ishak scores lower than 3 seemed to have fibrosis regression. The others were divided into the fibrosis progressive group and the nonprogressive group according to the 'Beijing fibrosis classification'. Predictors of fibrosis regression were studied by logistic regression using baseline factors and the dynamic change in noninvasive fibrosis factors. RESULTS: Eighteen patients were assigned to the progressive group, and the others were assigned to the nonprogressive group. The baseline liver stiffness measurements (LSMs) of the progressive and nonprogressive groups were 14.35 (11.3, 27.3) kPa and 11.3 (8.3, 14.2) kPa, respectively, P = 0.02. The baseline LSM was the only predictor of fibrosis progression. With a cutoff of 11.85 kPa, the AUC was 0.71 (0.5, 0.9), and the negative predictive value was 0.92. CONCLUSIONS: The baseline LSM was found to be the only predictor of fibrosis regression, 11.85 kPa is a possible 'hepatic fibrosis return point'.

Lower Circulating Interferon-Gamma Is a Risk Factor for Lung Fibrosis in COVID-19 Patients.

Cytokine storm resulting from SARS-CoV-2 infection is one of the leading causes of acute respiratory distress syndrome (ARDS) and lung fibrosis. We investigated the effect of inflammatory molecules to identify any marker that is related to lung fibrosis in coronavirus disease 2019 (COVID-19). Seventy-six COVID-19 patients who were admitted to Youan Hospital between January 21 and March 20, 2020 and recovered were recruited for this study. Pulmonary fibrosis, represented as fibrotic volume on chest CT images, was computed by an artificial intelligence (AI)-assisted program. Plasma samples were collected from the participants shortly after admission, to measure the basal inflammatory molecules levels. At discharge, fibrosis was present in 46 (60.5%) patients whose plasma interferon-γ (IFN-γ) levels were twofold lower than those without fibrosis (p > 0.05). The multivariate-adjusted logistic regression analysis demonstrated the inverse association risk of having lung fibrosis and basal circulating IFN-γ levels with an estimate of 0.43 (p = 0.02). Per the 1-SD increase of basal IFN-γ level in circulation, the fibrosis volume decreased by 0.070% (p = 0.04) at the discharge of participants. The basal circulating IFN-γ levels were comparable with c-reactive protein in the discrimination of the occurrence of lung fibrosis among COVID-19 patients at discharge, unlike circulating IL-6 levels. In conclusion, these data indicate that decreased circulating IFN-γ is a risk factor of lung fibrosis in COVID-19.

Capsaicin-loaded nanolipoidal carriers for topical application: design, characterization, and in vitro/in vivo evaluation.

Capsaicin has been used in clinical applications for the treatment of pain disorders and inflammatory diseases. Given the strong pungency and high oil/water partition coefficient of capsaicin, capsaicin-loaded nanolipoidal carriers (NLCs) were designed to increase permeation and achieve the analgesic, anti-inflammatory effect with lower skin irritation. Capsaicin-loaded NLCs were prepared and later optimized by the Box-Behnken design. The physicochemical characterizations, morphology, and encapsulation of the capsaicin-loaded NLCs were subsequently confirmed. Capsaicin-loaded NLCs and capsaicin-loaded NLCs gel exhibited sustained release and no cytotoxicity properties. Also, they could significantly enhance the penetration amount, permeation flux, and skin retention amounts of capsaicin due to the application of NLCs. To study the topical permeation mechanism of capsaicin, 3,3'-dioctadecyloxacarbocyanine perchlorate (Dio) was used as a fluorescent dye. Dio-loaded NLCs and Dio-loaded NLCs gel could effectively deliver Dio up to a skin depth of 260 and 210 µm, respectively, primarily through the appendage route on the basis of version skin sections compared with Dio solution, which only delivered Dio up to 150 µm. In vivo therapeutic experiments demonstrated that capsaicin-loaded NLCs and capsaicin-loaded NLCs gel could improve the pain threshold in a dose-dependent manner and inhibit inflammation, primarily by reducing the prostaglandin E2 levels in the tissue compared with capsaicin cream and capsaicin solution. Meanwhile, skin irritation was reduced, indicating that application of NLCs could decrease the irritation caused by capsaicin. Overall, NLCs may be a potential carrier for topical delivery of capsaicin for useful pain and inflammation therapy.

Reversal of tumor growth by gene modification of mesenchymal stem cells using spermine-pullulan/DNA nanoparticles.

Mesenchymal stem cells (MSCs) are a promising tool for delivering of therapeutic agents in cancer treatment. In the present study, our findings suggested that both i.v. and intratumoral injection of MSCs could favor tumor growth under physiologic conditions. However, the anti-tumor effects of MSC-IL-12 were achieved using our strategy. Unlike the previously reported method, the genetic engineering of MSCs was conducted by non-viral transfection using the new vector, spermine-pullulan. The transfection, cytotoxicity, and the cellular internalization of this vector were evaluated. Then, the therapeutical gene, IL-12, was delivered to the MSCs using this vector. The in vitro secretions of IL-12 by MSC-IL-12 confirmed the success of using spermine-pullulan/DNA nanoparticles for the gene transfection. We used the MSC-IL-12 for the in vivo treatment of both B16F10 metastasis tumor and the established subcutaneous B16BL6 tumor. For the B16F10 metastasis tumor, treatment with MSC-IL-12 significantly reduced lung metastases. For the established subcutaneous B16BL6 tumor, intratumoral injected MSC-IL-12 cells considerably retarded tumor growth. Prolonged survival was observed when MSC-IL-12 cells were injected through the tail vein or intratumorally, indicating that the MSCs engineered with the therapeutic gene could reverse the tumor-promoting effects of MSCs using the nonviral transduction method. However, the intravenous injected MSC-IL-12 did not prevent the tumor growth of the established subcutaneous B16BL6 tumor. Thus, we examined the the in vivo distribution of MSCs in different organs and it was found that MSCs were mainly distributed in the lungs, which may explain the inability of intravenously injected MSC-IL-12 to inhibit the growth of the established subcutaneous tumor.

Impregnation of plasmid DNA into three-dimensional PLGA scaffold enhances DNA expression of mesenchymal stem cells in vitro.

Current efforts had been made to undertake a three-dimensional (3-D) reverse transfection of bone marrow-derived mesenchymal stem cells (BM-MSCs) in PLGA scaffolds. As a kind of multipotent stem cells, BM-MSCs show great potential and tremendous capacity in the gene transfection field and PLGA 3-D scaffold has been shown to be a biomaterial that provides structural support to cells proliferation and tissue engineering. The objective of this study was to assess the transfection efficiency of BM-MSCs with a 3-D reverse transfection method by using PLGA scaffold and observe the SEM photographs of BM-MSCs cultured on PLGA scaffold. BM-MSCs were cultured in 3-D PLGA scaffold which was incorporated with pullulan-spermine/pGL3. It was shown that the gene expression duration of BM-MSCs transfected using 3D reverse method with pullulan-spermine/DNA in the presence of serum maintained 12 days at high levels as compared with the plasmid DNA in medium, and scanning electronic microscopy (SEM) photographs of BM-MSCs cultured on PLGA scaffold exhibited robust cell attachment and viability when cultured in PLGA scaffold in vitro. This study demonstrates that the 3-D reverse transfection method of BM-MSCs using PLGA scaffold could achieve long gene expression in a relatively high level, therefore this transfection system is promising in gene transfection and tissue engineering.

TGF-ß1 gene-engineered mesenchymal stem cells induce rat cartilage regeneration using nonviral gene vector.

This study evaluated the potential of utilizing transfected pTGFß-1 gene-engineered rat mesenchymal stem cells (MSCs) using nonviral vector to promote cartilage regeneration. Pullulan-spermine was used as the nonviral gene vector and gelatin sponge was used as the scaffold. MSCs were engineered with TGF-ß1 gene with either the three-dimensional (3D) reverse transfection system or the two-dimensional (2D) conventional transfection system. For the 3D reverse transfection system, pullulan-spermine/pTGF-ß1 gene complexes were immobilized to the gelatin sponge, followed by the seeding of MSCs. Pullulan-spermine/pTGF-ß1 gene complexes were delivered to MSCs cultured in the plate to perform the 2D conventional transfection system, and then MSCs were seeded to the gelatin sponge. Then, TGF-ß1 gene-transfected MSC seeded gelatin sponge was implanted to the full-thickness cartilage defect. Compared with the control group, both groups of TGF-ß1 gene-engineered MSCs improved cartilage regeneration through optical observation and histology staining. So, with pullulan-spermine as the nonviral vector, TGF-ß1-gene engineered MSCs can induce cartilage regeneration in vivo.

Effective gene delivery to mesenchymal stem cells based on the reverse transfection and three-dimensional cell culture system.

PURPOSE: To enhance the level and prolong the duration of gene expression for gene-engineered rat mesenchymal stem cells (MSCs) using non-viral vector. METHODS: A novel transfection system based on reverse transfection method and three-dimensional (3D) scaffold was developed. The reverse gene transfection system was evaluated for transfection efficiency compared to conventional methods. Collagen sponge and polyethylene terephthalate non-woven fabric were introduced as scaffolds to perform 3D culture with reverse transfection. pDNA coding TGFß-1 was delivered to MSCs to assess its ability in inducing chondrogenesis with the 3D non-viral reverse transfection system. RESULTS: The reverse transfection method induced higher transgene levels than the conventional transfection in the presence of serum. The electric charge of the anionic gelatin plays an important role in this system by affecting the release pattern of the gene complexes and through the adsorption of serum protein to the substrate. During a long-time in vitro culture, MSCs cultured on 3D scaffolds exhibited a higher transgene expression level and more sustained transgene expression than those cultured and transfected on the two-dimensional substrate. CONCLUSIONS: The combination of reverse transfection system with 3D cell culture scaffold benefits the cell proliferation and long-time gene transfection of MSCs.

[Detection of hepatic progenitor cells in patients with severe hepatitis and their distribution].

OBJECTIVES: To identify hepatic progenitor cells (HPCs) in patients with severe hepatitis (SH) by detecting their markers and investigate the features of their distribution and location. METHODS: Liver tissues taken from 59 SH patients were tested for the receptor of stem cell factor (c-kit), pi-class glutathione S-transferase (GST-pi), cluster of differentiation 34 (CD34), cytokeratin 19 (CK19), cytokeratin 18 (CK18) and alpha fetoprotein (AFP) by immunohistochemistry (IHC). Meanwhile, 58 patients with acute or chronic hepatitis were also detected to act as controls. RESULTS: Hepatic progenitor cells could be seen in SH patients. Most of them existed as ductular cells that had been called "typical ductular proliferation (ADP)" or "typical ductular reaction" in previous research. These ductular cells were mainly located at the portal areas, fibro septa, periportal parenchyma and the border of the pseudolobuli and inflammatory foci. Further, c-kit, GST-pi, CK19 and CK18, but not CD34 and AFP could be detected in these cells. Another kind of HPC was the small hepatocyte-like cell (SHLC), which could express c-kit, GST-pi, and CK18, but not CK19, CD34 and AFP. The semi-quantitative analysis showed that the scope of ADP in SH patients was significantly larger than that in acute and chronic hepatitis patients (chi2= 63.62, P<0.05), and the scope of ADP in subacute severe hepatitis and chronic severe hepatitis patients was also significantly larger than that in acute severe hepatitis patients. CONCLUSION: In the course of regeneration of viral hepatitis, different types of pathology have different features. In acute and chronic hepatitis (G1-2), the regeneration is mainly owing to the proliferation of mature hepatocytes, and in chronic hepatitis (G3-4), there is the participation of HPCs, although they are limited. In severe hepatitis, however, since the replicative capacity of normal hepatocytes is impaired or prohibited, liver regenerates and restores mainly by the means of hepatic stem cells activation and proliferation. But the hepatic stem cells don't differentiate into their mature functional compartments directly at all. There are several intermediary or transition populations. In human severe hepatitis, they are mainly ductular cells, and parts of them are small hepatocyte-like cells.

[Clinical features of severe acute respiratory syndrome in forty-one confirmed health care workers].

OBJECTIVE: To investigate the clinical features of severe acute respiratory syndrome (SARS). METHODS: Forty-one medical care workers (aged 23 - 55 years, with a average of 32 years; men/women = 8/32) who were admitted to our hospital and diagnosed with SARS during March and April, 2003 were retrospectively analyzed. RESULTS: Thirteen of all the patients were physicians and the rest were nurses. The disease was mainly transmitted through air droplet in a short distance, and overwork induced tiredness was involved in disease stimulation. Seventy-three percent of the patients presented fever as their first symptom. Ten patients complained inertia and myalgia. One patient showed no clinical symptoms, and bilateral infiltrates was found in his chest X-ray. Among the 41 cases, 6 (15%) were diagnosed as severe type. At the first week, the counts of white blood cells (WBCs), lymphocyte and platelets were (4.4 +/- 1.5) x 10(9)/L, 0.22 +/- 0.12 and (143 +/- 37) x 10(9)/L, which were significantly lower when compared with those at the 2nd to 4th week. Abnormal liver function was found in 27 cases (mostly with elevated serum ALT), with 70% occurred at the 3rd or 4th week. In terms of CT, 30 patients (73%) showed pathological changes in lungs, and bilateral lung involvement was found in 35.59%. Of 36 cases treated with steroids, 86% received middle or low dosage (80 - 240 mg/d). Artificial ventilation was used for twenty-seven patients, and air pipe mechanical ventilation was used for 1 case. Mortality in this study was 5%. CONCLUSIONS: Inertia and myalgia may be the earlier symptoms of health care workers with SARS include, which are parallel to CT manifestations. There is no objective index for the assessment of the severity of the disease at early stage. The medicine associated toxicities may be the main reason of liver lesions. damages. Middle or low dosage of steroid was reasonable to be used as early as possible.

[A clinicopathological study on nonalcoholic steatohepatitis].

OBJECTIVE: To observe the pathological and clinical characters of nonalcoholic steatohepatitis (NASH). METHODS: Liver biopsy tissues taken from 97 patients negative for common viral detection with serological test and immunohistochemistry as well as in situ hybridization, were observed by routine light microscopic examination. And the clinical data of patients with NASH was analyzed. RESULTS: Among the chronic hepatitis patients with unknown etiology, the detection rate of NASH was 15.5% (15/97). The characteristic lesions in NASH patients included macrovesicular steatosis in zone 3 of lobules, hepatocytes ballooning degeneration, lobules diffused with acute and chronic inflammation, and perisinusoidal fibrosis. Grading and staging according to Brunt's method, histological lesions could be accounted for G1S1 in 7 patients, G2S2 in 3 patients, G3S1 in 4 patients and G3S2 in 1 patient. There were 14 patients with mild to moderate elevation of transaminase, 10 with hyperlipemia, 8 with diabetes and 9 with fatty liver by ultrasonography. CONCLUSION: Nonalcoholic steatohepatitis is a common form of unknown etiology chronic liver disease with certain clinic-pathological features.

Clinicopathological study on TTV infection in hepatitis of unknown etiology.

AIM: To investigate the state of infection, replication site, pathogenicity and clinical significance of transfusion transmitted virus (TTV) in patients with hepatitis, especially in patients of unknown etiology. METHODS: Liver tissues taken from 136 cases of non-A non-G hepatitis were tested for TT virus antigen and nucleic acid by in situ hybridization (ISH) and nested-polymerase chain reaction (PCR). Among them, TT virus genome and its complemental strand were also detected in 24 cases of autopsy liver and extrahepatic tissues with ISH. Meanwhile, TTV DNA was detected in the sera of 187 hepatitis patients by nested-PCR. The pathological and clinical data of the cases infected with TTV only were analyzed. RESULTS: In liver, the total positive rate of TTV DNA was 32.4% and the positive signals were located in the nuclei of hepatocytes. In serus, TTV DNA was detected in 21.4% cases of hepatitis A-G, 34.4% of non-A non-G hepatitis and 15% of healthy donors. The correspondence rate of TTV DNA detection between liver tissue with ISH and sera with PCR was 63.2% and 89.3% in the same liver tissues by ISH and by PCR, respectively. Using double-strand probes and single-strand probes designed to detect TTV genome, the correspondence rate of TTV DNA detected in liver and extrahepatic tissues was 85.7%. Using single-strand probes, TTV genome could be detected in liver and extrahepatic tissues by PCR, but its complemental strands (replication strands) could be observed only in livers. The liver function of most cases infected with TTV alone was abnormal and the liver tissues had different pathological damage such as ballooning, acidophilia degeneration, formation of apoptosis bodies and focus of necrosis, but the inflammation in the lobule and portal area was mild. CONCLUSION: The positive rate of TTV DNA among cases of hepatitis was higher than that of donors, especially in patients with non-A non-G hepatitis, but most of them were coinfected with other hepatitis viruses. TTV can infect not only hepatocytes, but also extrahepatic tissues. However, the chief replication place may be liver. The infection of TTV may have some pathogenicity. Although the pathogenicity is comparatively weak, it can still damage the liver tissues. The lesions in acute hepatitis (AH) and chronic hepatitis (CH) are mild, but in severe hepatitis (SH), it can be very serious and cause liver function failure, therefore, we should pay more attention to TTV when studying the possible pathogens of so-called "liver hepatitis of unknown etiology".