Non-invasive diagnosis of non-alcoholic fatty liver disease: Current status and future perspective.

Non-alcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease throughout the world. Hepatocellular carcinoma (HCC) and liver cirrhosis can result from nonalcoholic steatohepatitis (NASH), the severe stage of NAFLD progression. By some estimates, NAFLD affects almost one-third of the world's population, which is completely new and serious public health issue. Unfortunately, NAFLD is diagnosed by exclusion, and the gold standard for identifying NAFLD/NASH and reliably measuring liver fibrosis remains liver biopsy, which is an invasive, costly, time-consuming procedure and involves variable inter-observer diagnosis. With the progress of omics and imaging techniques, numerous non-invasive serological assays have been generated and developed. On the basis of these developments, non-invasive biomarkers and imaging techniques have been combined to increase diagnostic accuracy. This review provides information for the diagnosis and assessment of NAFLD/NASH in clinical practice going forward and may assist the clinician in making an early and accurate diagnosis and in proposing a cost-effective patient surveillance. We discuss newly identified and validated non-invasive diagnostic methods from biopsy-confirmed NAFLD patient studies and their implementation in clinical practice, encompassing NAFLD/NASH diagnosis and differentiation, fibrosis assessment, and disease progression monitoring. A series of tests, including 20-carboxy arachidonic acid (20-COOH AA) and 13,14-dihydro-15-keto prostaglandin D2 (dhk PGD2), were found to be potentially the most accurate non-invasive tests for diagnosing NAFLD. Additionally, the Three-dimensional magnetic resonance imaging (3D-MRE), combination of the FM-fibro index and Liver stiffness measurement (FM-fibro LSM index) and the machine learning algorithm (MLA) tests are more accurate than other tests in assessing liver fibrosis. However, it is essential to use bigger cohort studies to corroborate a number of non-invasive diagnostic tests with extremely elevated diagnostic values.

Determining optimal ALT cut-off values for predicting significant hepatic histological changes in patients with normal ALT in the grey zone of chronic hepatitis B virus infection.

BACKGROUND AND AIMS: We aimed to define gender-specific, optimal alanine aminotransferase (ALT) cut-off values for the prediction of significant liver histological changes (SLHC) in Chinese patients with grey zone (GZ) chronic hepatitis B (CHB) and normal ALT. METHODS: In a retrospective study, we included 1101 consecutive patients with GZ CHB and normal ALT assigned to training or internal validation cohorts. We included an independent cohort of 842 patients for external validation. We performed receiver operating characteristic (ROC) curve, smoothed curve fitting, and threshold effect analyses to determine optimal ALT cut-off values. Area under the curve (AUC) values were calculated to assess their predictive performance. RESULTS: A proportion of 79.3% of patients with GZ CHB and normal ALT (≤40 U/L) had SLHC. ROC curve analysis initially identified optimal ALT cut-off values of 29 U/L (male) and 22 U/L (female). After smoothed curve fitting and threshold effect analyses, new optimal cut-off values were 27 U/L for males and 24 U/L for females. AUCs for these values were 0.836 (male) and 0.833 (female) in the internal validation cohort, and 0.849 (male) and 0.844 (female) in the external validation cohort. The accuracy and discriminative ability of the newly defined ALT cut-off values were greater than those of the current recommendations. CONCLUSION: This study established novel optimal ALT cut-off values for more precise prediction of SLHC among Chinese patients with GZ CHB and normal ALT levels. This may help identify individuals who will benefit from timely antiviral therapy.

Liver histopathological lesions is severe in patients with normal alanine transaminase and low to moderate hepatitis B virus DNA replication.

BACKGROUND: Chronic hepatitis B virus (HBV) infection remains a major global public health problem. Chronic hepatitis B (CHB) patients can be divided into treatment indication and non-treatment indication individuals according to alanine transaminase (ALT), HBV DNA, serum hepatitis B e antigen status, disease status [liver cirrhosis, hepatocellular carcinoma (HCC), or liver failure], liver necroinflammation or fibrosis, patients' age, and family history of HCC or cirrhosis. For example, normal ALT patients in 'immune-tolerant' phase with HBV DNA higher than 107 or 2 × 107 IU/mL, and those in 'inactive-carrier' phase with HBV DNA lower than 2 × 103 IU/mL do not require antiviral therapy. However, is it reasonable to set the defined values of HBV DNA as the fundamental basis to estimate the disease state and to determine whether to start treatment? In fact, we should pay more attention to those who do not match the treatment indications (gray-zone patients both in the indeterminate phase and in the 'inactive-carrier' phase). AIM: To analyze the correlation of HBV DNA level and liver histopathological severity, and to explore the significance of HBV DNA for CHB with normal ALT. METHODS: From January 2017 to December 2021, a retrospective cross-sectional set of 1299 patients with chronic HBV infection (HBV DNA > 30 IU/mL) who underwent liver biopsy from four hospitals, including 634 with ALT less than 40 U/L. None of the patients had received anti-HBV treatment. The degrees of liver necroinflammatory activity and liver fibrosis were evaluated according to the Metavir system. On the basis of the HBV DNA level, patients were divided into two groups: Low/moderate replication group, HBV DNA ≤ 107 IU/mL [7.00 Log IU/mL, the European Association for the Study of the Liver (EASL) guidelines] or ≤ 2 × 107 IU/mL [7.30 Log IU/mL, the Chinese Medical Association (CMA) guidelines]; high replication group, HBV DNA > 107 IU/mL or > 2 × 107 IU/mL. Relevant factors (demographic characteristics, laboratory parameters and noninvasive models) for liver histopathological severity were analyzed by univariate analysis, logistics analysis and propensity score-matched analysis. RESULTS: At entry, there were 21.45%, 24.29%, and 30.28% of the patients had liver histopathological severities with ≥ A2, ≥ F2, and ≥ A2 or/and ≥ F2, respectively. HBV DNA level (negative correlation) and noninvasive model liver fibrosis 5 value (positive correlation) were independent risk factors for liver histopathological severities (liver necroinflammation, liver fibrosis, and treatment indication). The AUROCs of the prediction probabilities (PRE_) of the models mentioned above (< A2 vs ≥ A2, < F2 vs ≥ F2, < A2 and < F2 vs ≥ A2 or/and ≥ F2) were 0.814 (95%CI: 0.770-0.859), 0.824 (95%CI: 0.785-0.863), and 0.799 (95%CI: 0.760-0.838), respectively. HBV DNA level (negative correlation) was still an independent risk factor when diagnostic models were excluded, the P values (< A2 vs ≥ A2, < F2 vs ≥ F2, < A2 and < F2 vs ≥ A2 or/and ≥ F2) were 0.011, 0.000, and 0.000, respectively. For the propensity score-matched pairs, whether based on EASL guidelines or CMA guidelines, the group with significant liver histology damage (≥ A2 or/and ≥ F2) showed much lower HBV DNA level than the group with non- significant liver histology damage (< A2 and < F2). Patients in the moderate replication group (with indeterminate phase) had the most serious liver disease pathologically and hematologically, followed by patients in the low replication group (with 'inactive-carrier' phase) and then the high replication group (with 'immune-tolerant' phase). CONCLUSION: HBV DNA level is a negative risk factor for liver disease progression. The phase definition of CHB may be revised by whether the level of HBV DNA exceeds the detection low limit value. Patients who are in the indeterminate phase or 'inactive carriers' should receive antiviral therapy.

MicroRNA-219-5p Inhibits Morphine-Induced Apoptosis by Targeting Key Cell Cycle Regulator WEE1.

BACKGROUND To identify the effects of microRNA (miR)-219-5p on morphine-induced apoptosis by targeting WEE1. MATERIAL AND METHODS Forty Balb/C mice (Toll-like receptor 9, TLR9 knockout) were randomly allocated to the experimental and control groups (20 in each group). The baseline miR-219-5p expression was detected using quantitative real-time PCR (qRT-PCR). After morphine was injected at 6 h on the 2nd and 6th days, experimental and control groups received miR-219-5p mimics or miRNA-negative control (NC), respectively, compound injection. Tissues and cells were later obtained from subjects in each group separately after mice were killed. TUNEL assay was used to investigate apoptosis in both groups. RAW264.7 cells were treated with miR-219-5p mimics and controls, respectively. After 24 h, 10 µM of morphine was added at 24 h. Cell apoptosis was assessed by flow cytometer. The WEE1 and Phospho-cdc2 (Tyr15) expressions were examined by Western blotting. RESULTS MiR-219-5p expression in the experimental group was significantly lower than that in the control group (P<0.05). Mice injected with miR-219-5p mimic experienced an evident increase in apoptosis rate compared with the control group (P<0.05). The miR-219-5p NC group and the morphine group both presented an elevated apoptosis rate compared with the blank control group (both, P<0.05). The apoptosis rate in the miR-219-5p mimic group was 10.06%, remarkably lower than in the miR-219-5p NC group and blank control group (both P<0.05). WEE1 and Tyr15 protein expressions in the miR-219-5p NC group and morphine group were obviously stronger than those in the blank control group (all P<0.05). In the miR-219-5p mimic group, WEE1 and Tyr15 protein expressions were significantly lower compared with those in the miR-219-5p NC group and morphine group (all P<0.05). CONCLUSIONS Morphine significantly downregulated the expression of miRNA-219-5p, which targets WEE1 to suppress Tyr15 expressions and activate Cdc2, thus inhibiting the morphine-induced macrophage apoptosis.

Outcomes of Interferon/Ribavirin Therapy in Patients with HCV Defined by Expression of Plasma Soluble Human Leukocyte Antigen-G but Not IL-37.

BACKGROUND Chronic hepatitis C virus (HCV) infection leads to life-threatening complications worldwide. Immunomodulation signals the response to virus clearance. The immune-suppressive molecule human leukocyte antigen-G (HLA-G) has been shown to function in inhibiting both innate and adaptive immune responses. The objective of this study was to investigate the expression of HLA-G and IL-37 in sustained virological response (SVR) and non-SVR HCV-positive patients before and after complete treatment with a combination of pegylated interferon (IFN) and ribavirin (RBV). MATERIAL AND METHODS Our study included 132 chronic hepatitis C patents who received combined therapy with IFN-a and RBV. Both SVR and non-SVR patients were included. The end-of-treatment response was defined as undetectable HCV RNA at week 48. Patients with end-of-treatment response were detected by HCV RNA at 24 weeks after therapy. The expression levels of HLA-G and IL-37 at the end and 24 weeks after treatment were detected by ELISA. RESULTS Plasma HLA-G and IL-37 were significantly increased in HCV-infected patients compared with healthy individuals before treatment. Furthermore, HLA-G in SVR patients was noticeably decreased after treatment, while HLA-G in non-SVR patients had no changes after treatment. Additionally, both in SVR and non-SVR patients, the expression of IL-37 was remarkably reduced compared with baseline after treatment. CONCLUSIONS These findings suggest that elevation of HLA-G and IL-37 in HCV may play an important role in response to combined therapy with IFN-a and RBV. Monitoring the expression of HLA-G during therapy could contribute to adjusting the treatment program of HCV-infected patients.

Evaluation of a rapid method for the simultaneous quantification of ribavirin, sofosbuvir and its metabolite in rat plasma by UPLC-MS/MS.

A rapid and sensitive ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method for the determination of ribavirin, sofosbuvir and its metabolite GS-331007 in rat plasma was established. The analytes and the internal standard (midazolam) were separated on an Acquity UPLC BEH C18 chromatography column (2.1mm×50mm, 1.7µm) using gradient elution with a mobile phase of acetonitrile and 0.1% formic acid in water at a flow rate of 0.4mL/min. The detection was performed on a triple quadrupole tandem mass spectrometer by multiple reaction monitoring (MRM) mode to monitor the precursor-to-product ion transitions of m/z 245.1→113.1 for ribavirin, m/z 530.3→243.1 for sofosbuvir, m/z 261.5→113.1 for GS-331007 and m/z 326.2→291.1 for midazolam (IS) using a positive electrospray ionization interface. The method was validated over a concentration range of 5-1000ng/mL for ribavirin, 10-2000ng/mL for sofosbuvir and 10-2000ng/mL for GS-331007. Total time for each chromatograph was 3.0min. The intra- and inter-day precision and accuracy of the quality control samples at low, medium, and high concentration levels exhibited relative standard deviations (RSD) <10.0% and the accuracy values ranged from -10.6% to 11.6%. The method was successfully applied to a pharmacokinetic study of ribavirin, sofosbuvir and GS-331007 in rats.

[Effects of autologous peripheral stem cell transplantation on acoustic radiation force impulse in patients with HBV-related decompensated cirrhosis].

OBJECTIVE: To perform a prospective study the effects of autologous peripheral blood stem cell (APBSC) transplantation on acoustic radiation force impulse (ARFI) in patients with hepatitis B virus (HBV)-related decompensated cirrhosis. METHODS: A total of 68 hospitalized patients with HBV-related decompensated cirrhosis undergoing conventional treatment were included in the study. Thirty-three of these patients also received APBSC transplantation therapy (treatment group) and 35 did not (control group). The treatment group was observed for postoperative adverse reaction, and changes (pre-vs.post-treatment) in total bilirubin, prothrombin time (PT), albumin (Alb), spleen size and ARFI imaging findings. Statistical analyses were carried out using the t-test, non-parametric test, and chi-square test. RESULTS: The patients who received APBSC transplantation showed improving levels of Alb and PT, but not of total bilirubin, at postoperative weeks 24, 36 and 48, and reduced spleen length and ARFI findings at postoperative weeks 36 and 48.Compared to the baseline data (week 0) for the treatment group and to the data for the control groups, these differences were statistically significant (P less than 0.05). CONCLUSIONS: APBSC transplantation can reduce ARFI imaging findings and improve the pathology of liver fibrosis in patients with HBV-related decompensated cirrhosis.

Resistant mutants induced by adefovir dipivoxil in hepatitis B virus isolates.

AIM: To investigate the loci of adefovir dipivoxil (ADV)-induced resistance in hepatitis B virus (HBV) isolates and optimize the management of ADV-treated patients. METHODS: Between June 2008 and August 2010, a cross-sectional control study was conducted comprising 79 patients with chronic HBV infection-related liver disease who had been administered ADV monotherapy. Patients underwent liver imaging. Serum DNA extracts were analyzed for HBV DNA levels, genotypes, and serology markers, and deep sequencing of the HBV P gene was performed. RESULTS: ADV-resistant patients were found either with a single mutated locus, or with coexisting mutated loci. The most prevalent mutations were rtA181T, rtV214A, and rtN236T. Twenty-six patients had more than two mutated loci. The mutants were distributed among the patients without any significant affinity for gender, age, end-stage of liver disease, complications of non-alcoholic fatty liver disease, or HBV DNA levels. Patients with the rtA181T mutant were primarily infected with genotype C and e-antigen negative HBV, while patients with the rtN236T mutant were primarily infected by genotype B HBV (χ(2) = 6.004, 7.159; P = 0.023, 0.007). The duration of treatment with ADV was shorter in the single mutant group compared with the multi-mutant group (t = 2.426, P = 0.018). CONCLUSION: Drug-resistant HBV mutants are complex and diverse. Patients should receive the standard and first-line antiviral treatment, strictly comply with medication dosage, and avoid short-term withdrawal.

Cryptotanshinone induces inhibition of breast tumor growth by cytotoxic CD4+ T cells through the JAK2/STAT4/ perforin pathway.

Cryptotanshinone (CPT), is a quinoid diterpene isolated from the root of the Asian medicinal plant, Salvia miotiorrhiza bunge. Numerous researchers have found that it could work as a potent antitumor agent to inhibit tumor growth in vitro, buith there has been much less emphasis on its in vivo role against breast tumors. Using a mouse tumor model of MCF7 cells, we showed that CPT strongly inhibited MCF7 cell growth in vivo with polarization of immune reactions toward Th1-type responses, stimulation of naive CD4+ T cell proliferation, and also increased IFN-γ and perforin production of CD4+ T cells in response to tumor-activated splenocytes. Furthermore, data revealed that the cytotoxic activity of CD4+ T cells induced by CPT was markedly abrogated by concanamycin A(CMA), a perforin inhibitor, but not IFN-γ Ab. On the other hand, after depletion of CD4+ T cells or blocked perforin with CMA in a tumor-bearing model, CPT could not effectively suppress tumor growth, but this phenomenon could be reversed by injecting naive CD4+ T cells. Thus, our results suggested that CPT mainly inhibited breast tumor growth through inducing cytotoxic CD4+ T cells to secrete perforin. We further found that CPT enhanced perforin production of CD4+ T cells by up-regulating JAK2 and STAT4 phosphorylation. These findings suggest a novel potential therapeutic role for CPT in tumor therapy, and demonstrate that CPT performs its antitumor functions through cytotoxic CD4+ T cells.

[Liver histopathological features influencing HBeAg seroconversion in patients with HBeAg-positive chronic hepatitis B responding to Peg-IFN treatment].

OBJECTIVE: To investigate the therapeutic efficiency of antiviral treatment with pegylated-interferon (Peg-IFN) for hepatitis B e antigen (HBeAg)-positive chronic hepatitis B (CHB) and to explore whether liver histopathological features or other factors influence the HBeAg seroconversion treatment response. METHODS: Eighty HBeAg-positive CHB patients with diagnosis confirmed by liver puncture were treated with Peg-IFN(2a or 2b)body weight dose, once weekly). At treatment week 48, the rate of HBeAg seroconversion was determined and used to analyze the influence of liver histopathological features (liver biopsy assessment of: inflammation, graded G0 to G4; fibrosis stage, graded S0 to S4), sex, age, differential levels (pre-treatment baseline vs. week 48 post-treatment) of serum alanine transferase (ALT), and HBV DNA, by binary logistic analysis. RESULTS: At week 48, the overall rate of HBeAg seroconversion was 30.0%. The rate of HBeAg seroconversion gradually advanced with increased liver inflammation (X2 = 8.435, P = 0.015): 9.09% of the 22 patients with G1; 31.58% of the 38 patients with G2; 47.30% of the 19 patients with G3; the one patient with G4. In contrast, the rate of HBeAg seroconversion showed a much weaker association with liver fibrosis (X2 = 5.917, P = 0.116). Only baseline HBeAg level, and no other baseline index, was significantly different between the patients who achieved HBeAg seroconversion and those who did not. Liver inflammation and baseline HBeAg level were identified as influencing factors of HbeAg seroconversion in response to Peg-IFN treatment. CONCLUSION: Peg-IFN therapy induces a higher rate of HBeAg seroconversion in HBeAg-positive CHB patients with severe liver inflammation; histological analysis of pre-treatment liver biopsies may help to identify patients most likely to benefit from the antiviral regimen.

[Clinical analysis of hepatitis B virus mutations related to adefovir dipivoxil among patients with chronic hepatitis B virus infection in eastern Zhejiang province].

OBJECTIVE: To explore the clinical characteristics of hepatic B virus (HBV) mutations related to adefovir dipivoxil (ADV) among patients with chronic HBV infection in eastern Zhejiang province and provide some reference values on normative usage of antiviral drugs. METHODS: The data of chronic HBV-infected patients with HBV mutations related to ADV (n = 88) and non-mutation (n = 202) from June 2008 to August 2010 were analyzed retrospectively. The gene resistance mutations of HBV P region were analyzed by gene sequencing. And the HBV genotypes, HBV serum markers, HBV DNA levels and liver imaging findings were also analyzed. RESULTS: There were 9 cases with pre-existing mutations in 88 patients. The mutated sites were multiple and complicated. And the mutated sites related to other antiviral drugs were all accompanied by ADV-related mutations. The single mutated site was mostly at rtA181T (46.59%) and at rtV214A (11.36%). There were 27 cases (30.68%) with ≥ two mutated sites. The constituent ratios of males, end-stage liver diseases, complicated nonalcoholic fatty liver disease (NAFLD) and HBV genotype C infection in the mutation group were higher than those in the non-mutation group (P < 0.01, < 0.01, 0.019, 0.045). The average ages in the mutation group were also higher than those in the non-mutation group (P < 0.001). But the constituent ratios of HBeAg positivity and the levels of HBV DNA were lower (P = 0.002, 0.02). CONCLUSION: There may be some cases with pre-existing ADV-related mutations in ADV treatment-naive patients. The mutated sites occur at multiple loci, mostly at rtA181T and rtV214A. The male patients and those with a longer history of HBV infection, HBeAg negativity, HBV genotype C infection, illness progression and complicated NAFLD may be more susceptible to mutation. It is important for patients to accept and implement standardized regimens of antiviral drugs so as to prevent resistance and avoid salvage therapy.

Clinicopathologic features and molecular analysis of enterovirus 71 infection: report of an autopsy case from the epidemic of hand, foot and mouth disease in China.

A 15-month boy with fatal hand, foot, and mouth disease (HFMD) exhibited atypical symptoms and progressed rapidly to death. An autopsy was performed the next day and tissue sections were stained for histopathological examination. His intestinal samples were tested for enterovirus 71 (EV71), and the whole-genome sequence of EV71 was analyzed. An autopsy revealed that the central nervous system, lungs, and gut displayed severe meningitis and brainstem encephalitis, remarkable pulmonary congestion, edema, moderate inflammatory infiltration, and hemorrhage as well as intestinal mucosal congestion, epithelial necrosis, thinning intestinal wall, and submucosal lymphoid follicular hyperplasia. The heart showed myocardial interstitial congestion, myocardial edema, and some inflammatory infiltrates. There were no significant alterations in the architecture of other organs. EV71 antigen and apoptotic cells were detected in brain, lung and intestine by immunohistochemical staining and TUNEL (TdT-mediated dUTP nick-end labeling) respectively. Intestinal contents and intestinal autopsy samples of this case were positive for EV71, and the EV71 strain was classified as subgenogroup C4. In China, the severe forms of HFMD were mostly caused by EV71 subgenogroup C4 infection. Severe intestinal damages may relate to EV71 subgenogroup C4 infection. Thus, children with severe EV71 HFMD may have serious pathological changes in their central nervous system, lungs, and gut. Physicians should pay special attention to infants with atypical symptoms, particularly in EV71 epidemic areas for early diagnosis and treatment.

Studies on separating the impedance change components of blood vessels and ventricles in thorax from mixed impedance signals on chest surface.

PURPOSE: The aim of the present study is to separate the impedance change components of the blood vessels and ventricles in thorax from the mixed impedance signals detected on the chest surface. METHODS: The mixed impedance signals on the chest surface are measured with a 15 electrode lead system. The thoracic impedance equations are established and solved iteratively with the algebraic reconstructed technique. Experiments were performed on 80 healthy, otherwise normal, adults. RESULTS: Five impedance change components for the aorta (AO), blood vessel in left lung (PL), blood vessel in right lung (PR), left ventricle (LV), and right ventricle (RV) are separated from the mixed impedance signals. The experiments show that the main waveform of the ventricular components LV and RV is contrary to that of the vascular components AO, PL, and PR, and the negative peak point of the waveform graphs of LV and RV are in phase with the second cardiac sound (S2). The waveform graphs of various components correspond with the physiological activities of the heart and blood vessels in a cardiac cycle. The statistical results for 80 normal adults show that the amplitude of AO is the largest and that of PL and PR is the next, while that of LV and RV is the smallest. There are significant differences between them (P < 0.01). CONCLUSIONS: The mathematical model and the measurement method for the separation in the present paper are feasible.

[Study on the relationship between HBV viral loads and the changes of liver pathological features in patients with HBeAg-negative chronic hepatitis B].

OBJECTIVE: To investigate the relationship between serum HBV DNA loads and liver histology damage in the patients with HBeAg-negative chronic hepatitis B. METHODS: The retrospective study was performed. The 514 patients were divided into two groups according to the HBeAg status and the HBeAg positive group was as control. The relationship among HBV DNA loads, live histological inflammation grades and fibrosis stages was analyzed. RESULTS: The HBV DNA loads in HBeAg-negative group and HBeAg-positive group were (5.38 +/- 1.27) log10 copies/ml and (6.80 +/- 1.18) log10 copies/ml respectively (P < 0.001). The inflammation grades and fibrosis stages of liver tissues in HBeAg-negative group were all significantly higher than those in HBeAg-positive group (P < 0.001). In HBeAg-negative group, HBV DNA loads displayed a positive correlation with the inflammation grades and fibrosis stages of liver tissues (P < 0.001). CONCLUSION: In the patients with HBeAg-negative chronic hepatitis B, HBV viral loads are lower than those with HBeAg-positive chronic hepatitis B, and HBV viral loads display a positive correlation with liver the inflammation grades and fibrosis stages of liver tissues.

Mechanism of the formation for thoracic impedance change.

The purpose of this study is to investigate the mechanism of the formation for thoracic impedance change. On the basis of Ohm's law and the electrical field distribution in the cylindrical volume conductor, the formula about the thoracic impedance change are deduced, and they are demonstrated with the model experiment. The results indicate that the thoracic impedance change caused by single blood vessel is directly proportional to the ratio of the impedance change to the basal impedance of the blood vessel itself, to the length of the blood vessel appearing between the current electrodes, and to the basal impedance between two detective electrodes on the chest surface, while it is inversely proportional to the distance between the blood vessel and the line joining two detective electrodes. The thoracic impedance change caused by multiple blood vessels together is equal to the algebraic addition of all thoracic impedance changes resulting from the individual blood vessels. That is, the impedance changes obey the principle of adding scalars in the measurement of the electrical impedance graph. The present study can offer the theoretical basis for the waveform reconstruction of Impedance cardiography (ICG).

[Analysis of risk factors of patients with chronic liver failure complicated invasive fungal infections].

OBJECTIVE: To evaluate the risk factors of chronic liver failure (CLF) complicated invasive fungal infections (IFI) and prevention and treatment. METHODS: The clinical data and risk factors of 52 patients with CLF complicated IFI were analyzed retrospectively and were compared with those not complicated IFI. Risk factors were analyzed by chi-square test and Logistic regression test and Ridit test. RESULTS: In 52 patients with CLF complicated IFI, there were 69 fungal infections in different tissue and organs, the most were in oral cavity, but other tissue and organs especially bellows infections were rising. Candida albicans infections were the most, but cryptococcus neoformans infections and aspergillus infections were rising. The risk factors included species of bacteria infections, serum total bilirubin, hospital days, times of antibiotics using, number of invasive operation, species of antibiotics and degrees of ascites. The mortality of patients with CLF complicated IFI were much higher than those not complicated IFI. CONCLUSION: Patients with CLF complicated IFI have poor progress and prognosis. The effective prevent methods are treating primary disease actively, reducing hospital days, detecting patients' body fluids closely, identifying source of infection as early as possible, using antibiotics correctly, reducing or avoiding invasive operation, using immunoactivators and disinfecting air regularly.