Search

Background and Aims: Chronic hepatitis B (CHB) can cause liver fibrosis and lead to cirrhosis and cancer. As the effectiveness of antiviral therapy to reverse liver fibrosis is limited, We aimed to evaluate the effect of An-Luo-Hua-Xian pill (ALHX) on fibrosis regression in CHB patients treated with entecavir (ETV)., Methods: Treatment-naïve patients with CHB were randomly treated with ETV alone or combined with ALHX (ETV+ALHX) between October 1, 2013 and December 31, 2020. Demographic, laboratory, and liver histology data before and after 78 weeks of treatment were collected. The Ishak fibrosis score (F) was used and fibrosis regression required a decrease in F of ≥1 after treatment., Results: A total of 780 patients were enrolled, and 394 with a second liver biopsy after treatment were included in the per-protocol population, 132 in ETV group and 262 in ETV+ALHX group. After 78 weeks of treatment, the fibrosis regression rate in the ETV+ALHX group was significantly higher than that of the ETV group at baseline F≥3 patients: 124/211 (58.8%) vs. 45/98 (45.9%), p =0.035. The percentage of patients with a decreased liver stiffness measurement (LSM) was higher in the ETV+ALHX group: 156/211 (73.9%) vs. 62/98 (63.%), p =0.056. Logistic regression analysis showed that ETV combined with ALHX was associated with fibrosis regression [odds ratio (OR)=1.94, p =0.018], and a family history of hepatocellular carcinoma was on the contrary. (OR=0.41, p =0.031)., Conclusions: ETV combined with ALHX increased liver fibrosis regression in CHB patients., Competing Interests: The authors have no conflict of interests related to this publication., (© 2023 Authors.)

Objective: To investigate whether the combination of neoadjuvant hyperthermic intraperitoneal chemotherapy (NHIPEC) plus intravenous neoadjuvant chemotherapy (IV NACT) has superior efficacy to IV NACT alone., Design: Retrospective cohort study., Setting: Two tertiary referral university hospitals., Population: Patients with ovarian cancer who received NACT-interval debulking surgery (IDS) between 2012 and 2020., Methods: The tumour response to NACT was evaluated with the chemotherapy response score (CRS) system. Survival outcomes were compared., Main Outcome Measures: CRS 3, progression-free survival (PFS), and overall survival (OS)., Results: In total, 127 patients were included, and 46 received NHIPEC plus IV NACT. The addition of NHIPEC was independently associated with an increased likelihood of CRS 3 (p = 0.033). Patients who received NHIPEC + IV NACT had significantly improved PFS compared with those who received IV NACT alone (median PFS: 22 versus 16 months, p < 0.001). The use of NHIPEC was identified as an independent predictor of PFS (p < 0.0001). OS did not differ significantly between treatment groups (p = 0.062), although a trend favouring NHIPEC was noted. Incidence of grade 3-4 adverse events and the surgical complexity score of IDS were similar between the two groups., Conclusions: Compared with IV NACT alone, the combination of NHIPEC and IV NACT resulted in improved tumour response and longer PFS. The addition of NHIPEC did not increase the risk of adverse effects or affect the complexity of IDS., (© 2022 John Wiley & Sons Ltd.)

Objective: To investigate whether CA125 normalization following neoadjuvant chemotherapy (NACT) can complement the chemotherapy response system (CRS) in the prognostication of patients with tubo-ovarian high-grade serous carcinoma (HGSC). Methods: In total, 118 HGSC patients who received NACT followed by interval debulking surgery (IDS) for FIGO stage IIIC-IV disease were included, and their clinical data were retrospectively reviewed. The primary endpoint was progression-free survival (PFS). Cox regression analysis was performed to identify predictors of PFS. Results: Following NACT, CRS3 was noted in 35 patients (29.7%), and CA125 normalization (≤ 35 U/ml) was noted in 54 patients (45.8%). Both CRS3 and CA125 normalization were identified as independent prognosticators of PFS. Combining these two factors, we stratified the 106 patients into three groups with different risks of recurrence: low-risk group (CRS3 + post-NACT CA125≤ 35 U/ml; n = 17, 14.4%), intermediate-risk group (CRS3 + post-NACT CA125 > 35 U/ml; n = 19, 16.1%) and high-risk group (CRS1-2; n= 82, 69.5%). The differences in PFS between the three groups were significant (log-rank test, P < 0.0001). In Cox regression analyses, the new stratification method was found to have an independent prognostic effect. Conclusion: Both the CRS system and the normalization of CA125 following NACT could reliably predict the risk of recurrence following primary treatment. The combination of the two factors refined the prognostic stratification of HGSC patients who were treated with NACT and IDS., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)

Background: The chemotherapy response score (CRS) system is a reproducible prognostic tool for patients receiving neoadjuvant chemotherapy (NACT) for tubo-ovarian high-grade serous carcinoma (HGSC). Achieving CRS 3 following NACT can be used as a surrogate for progression-free survival (PFS) and overall survival (OS). This study aimed to identify predictors of CRS 3 and develop a predictive nomogram. Methods: Data were extracted from 106 HGSC patients receiving NACT. Logistic regression was used to identify independent predictors for CRS 3. A nomogram was established based on the multivariate regression model. Results: All patients received three cycles of NACT, and CRS 3 was observed in 24 (22.6%) patients. Compared with patients in the CRS 1-2 group, patients in the CRS 3 groups had significantly improved PFS (log-rank test P < 0.0001). The multivariate regression analysis identified post-NACT CA125, percent decrease in CA125, post-NACT human epididymis protein 4 (HE4), and post-NACT hemoglobin level as independent predictors of CRS 3. The Hosmer-Lemeshow test showed goodness-of-fit of this regression model ( P = 0.272). The nomogram including these factors presented good discrimination (area under the curve = 0.82), good calibration (mean absolute error = 0.039), and a net benefit within the threshold probabilities of CRS 3 > 5%. Conclusions: We validated the prognostic role of the CRS system and developed a nomogram that predicts the possibility of CRS 3 following NACT. The nomogram helps to identify patients who would benefit the most from NACT. More studies are warranted to validate this model., (Copyright © 2020 Liang, Li, Wu, Liu, Wu and Li.)

Objective: In 2012, we proposed and described a modified triple incision technique (MTIT) for vulvar cancer patients with locally advanced disease. The MTIT has undergone a series of modifications, and a modified MTIT (M-MTIT) has been developed. The purpose of this study was to introduce the M-MTIT and compare it with the MTIT. Study design: This was a retrospective cohort study. Fifty-seven vulvar cancer patients with clinical stage T2 (≥ 4 cm) or T3 disease were included. Of these patients, 28 underwent the MTIT and 29 underwent the M-MTIT. Data on surgery-related complications and survival outcomes were compared. Results: Patients who were treated with the M-MTIT developed significantly less surgery-related morbidities than patients treated with the MTIT (24.1% vs. 60.7%, P = 0.005). Wound breakdown was the most common complication in our cohort, which occurred less frequently in the M-MTIT group than in the MTIT group (10.3% vs. 35.7%, P = 0.022). Multivariate logistic regression analysis identified the M-MTIT as an independent predictor of a reduced risk of wound breakdown. The incidence of other complications, including lymphedema, wound infection and cellulitis, was lower in the M-MTIT group than in the MTIT group; however, the differences did not reach statistical significance. The median follow-up time of this study was 33 months. Kaplan-Meier survival graphs did not show significant differences in recurrence-free survival or overall survival between the two groups. Conclusions: The M-MTIT correlates with lower morbidity rates than the MTIT and does not compromise oncological safety. The M-MTIT can be considered a safe and feasible option for vulvar cancer patients with locally advanced disease., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)

The deregulation of Bcl2L12 expression in cancer has been recognized, but the causative factors are unknown. Histone acetyltransferases (HAT) play critical roles in the regulation gene transcription. This study tests a hypothesis that the aberrant activities of HAT induce deregulation of Bcl2L12 in nasopharyngeal cancer (NPC). In this study, human NPC tissues were collected from the clinic. The expression of Bcl2L12 and HATs in NPC cells was analyzed by real time RT-PCR and Western blotting. NPC cell apoptosis was analyzed by flow cytometry. The results showed that by screening the subtypes of HAT, the levels of HAT1 were uniquely higher in NPC as compared with non-cancer nasopharyngeal tissue. The levels of Bcl2L12 in NPC cells were positively correlated with HAT1. HAT1 involved in the STAT5 binding to the Bcl2L12 promoter. HAT1 increased the expression of Bcl2L12. Bcl2L12 mediated the effects of HAT1 on suppressing NPC cell apoptosis. Absorption of the HAT1 shRNA plasmid-carrying liposomes induced NPC cell apoptosis. In conclusion, inhibition of HAT1 can induce NPC cell apoptosis via increasing Bcl2L12 expression, which can be a potential therapy for NPC treatment., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Coxsackievirus A16 (CA16) is one of the major pathogens associated with human hand, foot, and mouth disease (HFMD) in the Asia-pacific region. Although CA16 infections are generally mild, severe neurological manifestations or even death has been reported. Studies on CA16 pathogenesis and vaccine development are severely hampered because the small animal models that are currently available show major limitations. In this study, gerbils (Meriones unguiculatus) were investigated for their suitability as an animal model to study CA16 pathogenesis and vaccine development. Our results showed that gerbils up to the age of 21 days were fully susceptible to CA16 and all died within five days post-infection. CA16 showed a tropism towards the skeletal muscle, spinal cord and brainstem of gerbils, and severe lesions, including necrosis, were observed. In addition, an inactivated CA16 whole-virus vaccine administrated to gerbils was able to provide full protection to the gerbils against lethal doses of CA16 strains. These results demonstrate that gerbils are a suitable animal model to study CA16 infection and vaccine development.

Neurogenic pulmonary edema caused by severe brainstem encephalitis is the leading cause of death in young children infected by Enterovirus 71 (EV71). However, no pulmonary lesions have been found in EV71-infected transgenic or non-transgenic mouse models. Development of a suitable animal model is important for studying EV71 pathogenesis and assessing effect of therapeutic approaches. We had found neurological disorders in EV71-induced young gerbils previously. Here, we report severe pulmonary lesions characterized with pulmonary congestion and hemorrhage in a gerbil model for EV71 infection. In the EV71-infected gerbils, six 21-day-old or younger gerbils presented with a sudden onset of symptoms and rapid illness progression after inoculation with 1×105.5 TCID50 of EV71 via intraperitoneal (IP) or intramuscular (IM) route. Respiratory symptoms were observed along with interstitial pneumonia, pulmonary congestion and extensive lung hemorrhage could be detected in the lung tissues by histopathological examination. EV71 viral titer was found to be peak at late stages of infection. EV71-induced pulmonary lesions, together with severe neurological disorders were also observed in gerbils, accurately mimicking the disease process in EV71-infected patients. Passive transfer with immune sera from EV71 infected adult gerbils with a neutralizing antibody (GMT=89) prevented severe pulmonary lesion formation after lethal EV71 challenge. These results establish this gerbil model as a useful platform for studying the pathogenesis of EV71-induced pulmonary lesions, immunotherapy and antiviral drugs.

Background: Recent reports have characterized virological and clinical features of the novel reassortant avian-origin influenza A (H7N9) virus. However, cardiovascular involvement during H7N9 infection is still unclear. In this study, we evaluate cardiac injury among H7N9-infected patients., Materials and Methods: A total of 40 patients who were laboratory-confirmed with H7N9 infection were retrospectively included and grouped by Acute Physiology and Chronic Health Evaluation II (APACHE II) score into four subgroups I(0-10), II(11-20), III(21-30) and IV(31-71). Cardiovascular complications and markers of cardiac injury including creatinine kinase (CK), CK iso-enzyme (CK-MB), cardiac troponin I (cTNI) and brain natriuretic peptide (BNP) were assessed. Electrocardiogram (ECG) and echocardiography (ECHO) were also performed., Results: Half of patients manifested with cardiovascular complications, with hypotension (47.5%) and heart failure (40.0%) the most prevalent. CK, CK-MB and cTNI showed marked increase with H7N9 virus infection but significantly decreased after H7N9 viral tests turned negative. More than half of patients presented with an abnormal ECG, but most of them are benign changes. ECHO examination showed different degree of impairment of cardiac function. Pulmonary artery systolic pressure was increased in all groups. Cardiac damage was more evident in patients with higher APACHE II score., Conclusions: H7N9 virus exerts a transient impairment on the cardiovascular system. Patients with a higher APACHE II score are more susceptible to cardiac damage., (© 2014 Stichting European Society for Clinical Investigation Journal Foundation.)

Objectives: In the winter of 2013, people were facing the risk of human-to-human transmission of the re-emerging influenza A(H7N9) virus. We report herein information on the clinical features of two patients from the same family infected with this virus, the genomic sequences of the viruses harbored, and antiviral drug sensitivity., Methods: Clinical and epidemiological data of two patients from the same family were collected and analyzed. Sequencing was done for the viruses isolated from these two patients and one epidemiologically related chicken, and the sequences of the eight gene segments of the viruses were analyzed phylogenetically. The sensitivity of the viruses to antiviral drug treatment was determined by neuraminidase inhibitor susceptibility test., Results: The two patients from one family cluster shared the same symptoms but had different outcomes, and had a strong epidemiological link. Three strains, two from these two patients and one from the chicken, were isolated. Genome sequencing and analyses of phylogenetic trees demonstrated that the two viruses were almost identical. We noted the presence of the PB2 E627K amino acid substitution that was not present in isolates from the first wave, as well as two new mutations in the NA gene and six in the PB2 gene. Drug sensitivity testing showed that the new isolates were resistant to oseltamivir but sensitive to peramivir., Conclusions: The two patients from one family cluster were probable human-to-human transmission cases. The new isolates were sensitive to peramivir but showed reduced sensitivity to oseltamivir., (Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background: Appropriate antimicrobial dosing for patients receiving continuous venovenous hemofiltration (CVVH) is complex. Pharmacist participation in antimicrobial dosing adjustment for patients receiving CVVH may be advantageous., Methods: A comparative study was performed in a China hospital intensive care unit (ICU).Patients receiving CVVH in the intervention group received antimicrobial dosing adjustment service by pharmacists from January 2012 to June 2012, whereas patients in the control group received routine medical care between July 2012 and December 2012. The primary outcomes including patients' length of ICU stay, mortality in ICU, ICU hospitalization costs, and the occurrence of adverse drug events (ADEs) were then compared., Results: 87 and 93 patients were included in the control and intervention groups. During the intervention period, pharmacists made 256 antimicrobial dosing adjustment recommendations for 93 enrolled patients receiving CVVH, of which 224 (87.5%) recommendations were accepted by physicians. Changing in CVVH-related variables (175, 68.4%) were the most common risk factors for dosing errors, whereas β-lactams (131, 51.2%) were the most frequency of antimicrobials associated with dosing errors. Compared with the control group, pharmacist dosing adjustment resulted in £1637.7 cost savings per patient, and 2.36 times reduction of antimicrobial-related adverse drug events (ADEs) (11 vs 26, P=0.002), while length of ICU stay and mortality in ICU showed no significant difference (P>0.05)., Conclusions: The involvement of pharmacist to participate in the ICU team rounds for patients receiving CVVH is associated with cost savings and reduction of ADEs. Hospital may consider employing ICU pharmacists., (Copyright © 2014 European Federation of Internal Medicine. Published by Elsevier B.V. All rights reserved.)

Background: During the spring of 2013, a novel avian-origin influenza A (H7N9) virus emerged and spread among humans in China. Data were lacking on the clinical characteristics of the infections caused by this virus., Methods: Using medical charts, we collected data on 111 patients with laboratory-confirmed avian-origin influenza A (H7N9) infection through May 10, 2013., Results: Of the 111 patients we studied, 76.6% were admitted to an intensive care unit (ICU), and 27.0% died. The median age was 61 years, and 42.3% were 65 years of age or older; 31.5% were female. A total of 61.3% of the patients had at least one underlying medical condition. Fever and cough were the most common presenting symptoms. On admission, 108 patients (97.3%) had findings consistent with pneumonia. Bilateral ground-glass opacities and consolidation were the typical radiologic findings. Lymphocytopenia was observed in 88.3% of patients, and thrombocytopenia in 73.0%. Treatment with antiviral drugs was initiated in 108 patients (97.3%) at a median of 7 days after the onset of illness. The median times from the onset of illness and from the initiation of antiviral therapy to a negative viral test result on real-time reverse-transcriptase-polymerase-chain-reaction assay were 11 days (interquartile range, 9 to 16) and 6 days (interquartile range, 4 to 7), respectively. Multivariate analysis revealed that the presence of a coexisting medical condition was the only independent risk factor for the acute respiratory distress syndrome (ARDS) (odds ratio, 3.42; 95% confidence interval, 1.21 to 9.70; P=0.02)., Conclusions: During the evaluation period, the novel H7N9 virus caused severe illness, including pneumonia and ARDS, with high rates of ICU admission and death. (Funded by the National Natural Science Foundation of China and others.).

A reliable disease model mimicking Enterovirus 71 (EV71) infection in humans is essential for understanding pathogenesis and for developing a safe and effective vaccine. Commonly used rodent models including mouse or rat models are not suitable for vaccine evaluation because the rodents are resistant to EV71 infection after they reach the age of 6 days. In this study, 21-day-old gerbils inoculated intraperitoneally (IP) with a non mouse-adapted EV71 strain developed neurological lesion-related signs including hind limb paralysis, slowness, ataxia and lethargy similar to those of central nervous system (CNS) infection of EV71 in humans. The infected gerbils eventually died of the neurological lesions and EV71 could be isolated from lung, liver, spleen, kidney, heart, spinal cord, brain cortex, brainstem and skeletal muscle. Significantly high virus replication was detected in spinal cord, brainstem and skeletal muscle by cellular analysis, real-time quantitative PCR (RT-PCR) and immunohistochemical staining. Histopathologic changes such as neuronal degeneration, neuronal loss and neuronophagia were observed in spinal cord, brain cortex, brainstem, and skeletal muscle along with necrotizing myositis and splenic atrophy. Gerbils that received two doses of inactive whole-virus vaccine showed no EV71-specific symptoms after challenged with EV71. In contrast, gerbils that received mock vaccination died of EV71-induced neuropathology after challenged with EV71. The result indicates that gerbils can serve as a reliable disease model for evaluating safety and efficacy of EV71 vaccine.

Objective: To investigate the expression of CD95 and special marker for activation of peripheral blood lymphocytes in patients with hand foot and mouth disease (HFMD) and its significance., Methods: Immunofluorescent two-color flow cytometry was used to study the expression of CD95 and HLA-DR on lymphocytes in 58 patients with HFMD and 34 normal controls., Results: Expression of CD3+ T cells was significantly lower in patients (63.82 +/- 7.74)% than that in controls (P < 0.001), meanwhile the expression of CD4+ T cells was (34.29 +/- 7.33)%, significantly lower than that of the controls (P < 0.005). The percentage of lymphocytes expressing HLA-DR in patients was (23.77 +/- 5.78)%, significantly higher than that of the controls (P < 0.005). Significant difference was observed in the expression of HLA- DR on CD8+ T cells in patients (1.34 +/- 1.12)% as compared with controls (P < 0.005). No significant difference in the expression of CD95 on lymphocytes was observed between patients and the controls (P > 0.05)., Conclusion: The findings support that cellular immunodeficiency exists in patients and that lymphocytes were abnormally activated in the patients. The activation of peripheral blood T lymphocytes in patients mainly involves CD8 subset and it may play an important role in the immune response to antiviral infection.

Objective: To study the application of decision tree in the research of anemia among rural children., Methods: In the Enterprise Miner module of software SAS 8.2, 3000 observations were sampled from database and the decision tree model was built. The model using decision tree of CART bases on Gini impurity index., Results: The misclassification rate of decision tree model was, training set 21.2%, validation set 21.9%. The Root ASE of decision tree model was, training set 0.399, validation set 0.404. The area under the ROC curve was larger than the reference line. The diagnostic chart showed that the corresponding percentage was higher than the other. The decision tree model selected 9 important factors and ranked them by their power, among which mother of anemia (1.00) was the most important factor. Others were children's age (0.75), time of ablactation (0.53), mother's age (0.32), the time of egg supplementation (0.26), category of the project county (0.26), the time of milk supplementation (0.16), number of people in the family (0.13), the education status of the mother (0.12). Decision tree produced simple and easy rules that might be used to classify and predict in the same research., Conclusion: Decision tree could screen out the important factors of anemia and identify the cutting-points for factors. With the wide application of decision tree, it would exhibit important application values in the research of the rural children health care.

A 4-factorial (water temperature, salinity, nitrogen, and phosphorus) experiment was designed to study the niche characteristics of four common microalgae communities in prawn-aquaculture pond. The results showed that the niche breadth was the greatest for Cryptomonas erosa in temperature and salinity resources (0.980 and 0.988, respectively) and for Niztzschia closterium in nitrogen and phosphorus resources (0.990), but the smallest for Chlorella pyrenoidosa in all test resources, with an average value of 0.926. As for niche overlap, it was the smallest for C. erosa and C. pyrenoidosa in temperature and salinity resources (0.809 and 0.702, respectively) and for C. erosa and N. closterium in nitrogen and phosphorus resources (0.829), but the greatest for C. pyrenoidosa and Nannichloropsis oculata in temperature, salinity, and nitrogen and phosphorus resources, with the values being 0.986, 0.974 and 0.989, respectively. All of these suggested that in prawn-aquaculture pond, C. erosa could be bred with any other three of the microalgae communities, while N. oculata and C. pyrenoidosa should not be bred together for their obvious competition

A pPICZ alpha1 vector was reconstructed with pPICZ alpha vector and PCR product of His4-Kan sequence from pPIC9K vector. The sequence encoding human brain-derived neurotrophic factor (hBDNF) was inserted into pPICZ alpha1. The expression vectors carrying 1, 2, 3, 6 copies of expression cassettes were constructed and transformed into Pichia pastoris GS115 respectively. The transformants were screened with G418/Zeocin and induced by 0.5% methanol, and the results of SDS-PAGE confirmed that the expression protein was about 14 kD and the percentage of the protein was about 20% of the total secreted protein. ELISA and Western blot analysis demonstrated that the protein could be specifically combined with chicken antibodies to human-BDNF.

Objective: To explore the point mutation in hepatitis B virus polymerase (HBV P) gene in HBV-infected patients resistant to lamivudine., Methods: HBV P gene was amplified by PCR and the products was sequenced to analyze the YMDD mutation. Then the variants were detected by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) with the following restriction enzymes: Fok I, Ssp I, Alw441 and were separated by 8.0% polyacrylamide gel electrophoresis., Results: Comparing with the sequences of standard HBV genome, there were 16 patients with G743C mutation and 1 patient with G743A mutation, and the codon ATG turned to ATC and ATA, YMDD motif changed into YIDD. But this kind of YIDD mutation was not proved by PCR-RFLP assay in the 17 patients., Conclusions: The G743C and G743A mutations in HBV P gene, resulting in YMDD motif changed into YIDD, are detected only by direct sequencing, not by PCR-RFLP. The new kind of G743C and G743A point mutations in HBV P gene is important for the detection of HBV P gene YMDD mutation.

Objective: To study the types and emergence time of YMDD motif mutation in hepatitis B virus (HBV) polymerase gene during lamivudine treatment., Methods: The serum samples were collected from 33 patients with HBV DNA rebounding and 2 non-responders after at least one year lamivudine treatment. HBV polymerase gene was amplificated by PCR, then the products were detected by restriction fragment length polymorphism (RFLP) and by direct sequence analysis., Results: The variants with YMDD mutation were 14 out of the 35 patients. Mutation patterns detected in these patients included four YIDD, six YVDD, three YI/VDD and one YI/MDD. The mean emergence time of YMDD variants was 11.07+/-3.65 months after the treatment, and the earliest one and the latest one occurred 5 months and 17 months after the treatment respectively. The emergence times of YIDD, YVDD, YI/VDD were (10.00 +/- 1.41) months, (11.67 +/- 4.41) months and (13.33 +/- 3.31) months respectively, which had no statistical significance (F = 0.543, P < 0.05). Three patients treated with lamivudine 200 mg every day after the mutation were followed up for 6 months, whose HBV variants had not vanished., Conclusions: There are many kinds of HBV variants after lamivudine treatment, including YIDD, YVDD, YI/VDD and YI/MDD. The emergence time of variants is quite variable between different types and the mean time is (11.07 +/- 3.65) months after treatment, and there is no relationship between the type of YMDD mutation and the time of lamivudine administration.

Objective: To analyse the emergence of YMDD motif (tyrosine-methionine-aspartate-aspartate) variants in patients with hepatitis B treated with lamivudine., Methods: The amino acid substitution from methionine or isoleucine at the YMDD motif at the HBV polymerase gene is a main mutation resistant to lamivudine treatment. Generated from a fragment of domain C of the polymerase gene, patients' HBV DNA, which had been positive previously became positive again ever since it had been negative during lamivudine therapy. Variants were detected by cleavage of the products of the three PCRs with following enzymes: FokI, SspI, Alw441. The results of PCR-RELP were analysed by 8.4% polypropylene acidemide gel electrophoresis. PCR-RFLP assay was compared to direct sequencing., Results: HBV DNA was positive again in 33 patients and positive for one year in 2 patients. YMDD variants were detected in serum 14 of 35 patients, YIDD variants in 4, YVDD variants in 6, and YI/MDD variants in 1; all were in concordance with the results of direct sequencing. The samples of other 3 patients showed YI/VDD mutations, as shown by direct sequencing. The results of PCR-RFLP assay of the mixed sera of YIDD and YVDD variants were similar to those sera of YI/VDD variants., Conclusion: PCR-RFLP is suitable for rapid detection of YMDD variants of viral polymerase in hepatitis B virus patients treated with lamivudine.