Slit1 promotes regenerative neurite outgrowth of adult dorsal root ganglion neurons in vitro via binding to the Robo receptor.

Secreted Slit proteins have previously been shown to signal through Roundabout (Robo) receptors to negatively regulate axon guidance and cell migration. During vertebrate development, Slit proteins have also been shown to stimulate branching and elongation of sensory axons and cortical dendrites. In this study, Slit1/Robo2 mRNA and protein expressions were detected in adult rat dorsal root ganglion (DRG) and in cultured DRG neurons. Treatment of both models with recombinant, soluble Slit1 protein was found to promote neurite outgrowth and elongation. In contrast, treatment with a recombinant human Robo2/Fc chimera inhibited neurite outgrowth and elongation. When adult DRG and cultured DRG neurons were pretreated with soluble recombinant human Robo2/Fc chimera, neurite outgrowth and elongation was not induced. These findings indicate that Slit1/Robo2 signaling may have a role in regulating peripheral nerve regeneration.

Sensitive detection of the K103N non-nucleoside reverse transcriptase inhibitor resistance mutation in treatment-naïve HIV-1 infected individuals by rolling circle amplification.

Primary or transmitted antiretroviral drug resistance mutations pose a significant obstacle for optimizing antiviral treatment. When present at low-levels, resistance mutations are less likely to be detected by standard genotyping assays. This study utilizes a novel rolling circle amplification (RCA) method using padlock probes to achieve the sensitive, specific and low-level detection of the NNRTI resistance K103N from 59 HIV+ treatment-naïve patients from Beijing, China. Using standard genotyping methods, primary drug resistance mutations to either protease or RT inhibitors were found in 25% (15/59) of patients attending hospital clinics in Beijing. Among these 15 patients with antiretroviral (ARV) resistance mutations, standard sequence-based genotyping revealed that most (10/15) had the 103N. Using a highly sensitive RCA assay, 5 more patients among the 59 treatment-naïve cohort were found to have the 103N, but at low-levels, leading to an overall rate of 103N at 25.4% (15/59) in this population. The high prevalence of the 103N suggests that baseline resistance testing should be performed before treatment in this population. Importantly, the new RCA technology allows large-scale, sensitive detection of drug resistance mutations, including detection of minority populations with minimal equipment requirement.

Correlation of hepatitis B virus (HBV) genotypes and mutations in basal core promoter/precore with clinical features of chronic HBV infection.

BACKGROUND/AIMS: To investigate the correlation of hepatitis B virus (HBV) genotypes and basal core promoter (BCP) and precore (PC) mutations in patients with chronic hepatitis B. METHODS: HBV genotyping, nucleotide mutation, serum HBV DNA level and serological markers were analyzed in 121 patients with chronic HBV infection using INNO-LiPA HBV genotyping, polymerase chain reaction (PCR) product-based sequencing, fluorescence quantitative PCR and enzyme-linked immunosorbent assays respectively. RESULTS: Forty (33.0%), 77 (63.6%), two (1.7%) and two (1.7%) patients had genotypes B, C, B/C and D infections respectively. Significant differences were found in serum HBV DNA levels (log10 copies/ml: 6.18 vs. 5.61, P=0.042) and mutations at nucleotide (nt) 1762/1764 (71.4% vs. 42.5%, P=0.002) between genotypes C- and B-infected patients. There were significant differences in the mean age, serum biochemical parameter levels and mutation rates in BCP/PC among hepatitis e antigen (HBeAg)-positive and -negative chronic hepatitis B (CHB) and liver cirrhosis (LC) groups. CONCLUSION: Genotypes C and B are predominant in China, and the frequent nt 1762/1764 mutation, which occurs commonly in HBeAg-negative CHB, especially in genotype C patients, may be associated with the progress of chronic HBV infection.

[Relationship between B virus hepatitis genotypes and therapeutic efficacy in early treatment for chronic hepatitis B by using lamivudine].

OBJECTIVE: To investigate the relationship between hepatitis B virus (HBV) genotype and therapeutic efficacy during the early phase of lamivudine treatment. METHODS: Totally 595 patients with chronic hepatitis B were treated with lamivudine 100 mg/day for 12 months. HBV genotypes, contents of HBV DNA, HBeAg/anti-HBe and YMDD mutation after lamivudine treatment for 12 months were determined. The data were analyzed with SPSS software. RESULTS: In 595 patients, 8 (1.4%) were genotype A; 53 (8.9%) genotype B; 360 (60.5%) genotype C; 112 (18.8%) were coinfection of genotype B and C; 14 (2.4%) of A and C; 15 (2.5%) A and B; 6 (1.0%) of A, B, and C, and remaining 27 (4.5%) were unspecified. Patients were treated with lamivudine 100 mg/day for 12 months. Genotype B with HBV DNA levels turned to be negative (HBV DNA < 0.1 ng/L) was 87.2%, genotype C was 89.51%, coinfection of genotype B and C was 93.04% (P > 0.05). HBeAg seroconversion of genotype B was 11.65%, of genotype C was 20.64%, and of coinfection of genotype B and C was 18.57% (P > 0.05). All 69 strains of YMDD mutation were detected after lamivudine treatment for 12 months, in which genotype B was in 16.98%, genotype C in 15.38%, and coinfection of genotype B and C was in 13.86% (P > 0.05). CONCLUSION: There was no difference in HBV genotypes and the rate of development of YMDD mutations, HBeAg seroconversion, descending of HBV DNA level in Chinese patients with chronic hepatitis B.

[Dynamics of peripheral blood B lymphocytes and natural killer cells in patients with severe acute respiratory syndrome].

OBJECTIVE: To study the dynamics of peripheral blood B lymphocytes and natural killer (NK) cells in patients with severe acute respiratory syndrome (SARS). METHODS: The absolute numbers of peripheral blood B lymphocytes and NK cells in 602 serial samples from 240 patients with SARS were counted, using flow cytometry, and compared with that of normal population. RESULTS: The absolute numbers of peripheral blood B lymphocytes and NK cells in SARS patients were significantly lower than that of the normal population (P < 0.001) and were much lower in SARS patients with severe or extremely severe types, as compared with that of moderate or mild type cases (P < 0.001). The amount of B lymphocytes in recovery SARS patients increased at the 2nd week after onset, and gradually becoming normal at the 5th week of the disease onset. The number of NK cells was in the low level at onset, and keep decreasing at the 2nd week. However, it was increasing with the recovery of the disease, but did not reach to normal level at the 5th week after onset. CONCLUSION: The absolute numbers of peripheral blood B lymphocytes and NK cells were associated with the severity of the disease, and detection of these two kinds of cells was useful for predicting the prognosis of SARS.

[Dynamics of peripheral blood lymphocytes and their subpopulations in patients with severe acute respiratory syndrome].

OBJECTIVE: To study on the dynamics of peripheral blood lymphocytes and their subpopulations in patients with severe acute respiratory syndrome. METHODS: Using flow cytometry, the absolute numbers of peripheral blood lymphocytes and their subpopulations in 240 SARS patients (696 specimens) and 51 individuals as controls, were counted and compared. RESULTS: The absolute numbers of peripheral blood lymphocytes and their subpopulations (CD45, CD3, CD4, CD8) were 1298 +/- 785, 897 +/- 606, 510 +/- 372, 362 +/- 263/mm(3), respectively, significantly lower in SARS patients as compared to the normal controls (2024 +/- 423, 1391 +/- 289, 795 +/- 129, 551 +/- 183/mm(3)). Of SARS patients, severe group (1095 +/- 740, 740 +/- 562, 419 +/- 346, 304 +/- 244/mm(3)) had lower counts than that of mild group (1404 +/- 788, 991 +/- 612, 564 +/- 378, 396 +/- 267/mm(3)), and in group with deaths (587 +/- 493, 369 +/- 371, 204 +/- 191, 150 +/- 130/mm(3)) was lower than that of recovery group (1355 +/- 776, 948 +/- 603, 539 +/- 375, 382 +/- 263/mm(3)). There were significant differences (P < 0.01) for CD45, CD3, CD4, CD8, but with no significant difference (P > 0.05) for CD4/CD8 ratio between severe and mild, recovery and death groups. The lymphocytes and their subpopulations (CD45, CD3, CD4, CD8) declined in the 1st week and to the lowest level (977 +/- 579, 641 +/- 466, 360 +/- 275, 270 +/- 216/mm(3)) in the 2nd week. Then the lymphocytes and their subpopulations gradually increased during the recovery of the disease. CONCLUSION: The absolute numbers of peripheral blood lymphocytes and their subpopulations in SARS patients might be used as one of the methods for diagnosis on the severity and prognosis of the disease.

[Detection for severe acute respiratory syndrome (SARS) coronavirus RNA in stool of SARS patients].

OBJECTIVE: To investigate excretion of severe acute respiratory syndrome coronavirus RNA (SARS-CoV) in stool of SARS patients. METHODS: SARS-CoV RNA was detected in stool specimens with fluorescent quantitative polymerase chain reactions (FQ-PCR) in 101 SARS patients on the 10 to 55 days after onset, 27 non-SARS patients and 400 individuals with health check-up. RESULTS: SARS-CoV RNA was positive in stool specimens by FQ-PCR in 58 of 101 SARS patients (57.4%), and all negative in 27 non-SARS patients and 400 healthy individuals. Positive rate of SARS-CoV RNA was 100% (8/8), 67.7% (21/31), 47.4% (27/57) and 40.0% (2/5) on the 10 - 19, 20 - 29, 30 - 39 and 40 - 55 days after onset of fever, respectively, with values of logarithm of SARS-CoV RNA load of 6.06 +/- 2.05, 4.51 +/- 1.23, 3.82 +/- 1.44 and 3.57 +/- 1.25, respectively. CONCLUSION: Positive rate and load of SARS-CoV RNA in stool of SARS patients was the highest at their acute phase, and decreased with the extension of its course.

[Rapid detection of genotypes of TT virus using a heteroduplex mobility assay].

OBJECTIVE: To establish a simple, sensitive, specific and less-costly method for detecting genotypes of TT virus (TTV). METHODS: TTV DNA was tested by nested polymerase chain reaction (nPCR) in sera from 180 patients with different types of viral hepatitis and 96 normal individuals in Beijing. TTV genotypes were determined in 40 sera collected from TTV DNA positive patients by heteroduplex mobility assay (HMA) and through sequencing. RESULTS: The positive rates of TTV DNA in viral hepatitis patients and normal individuals were 22.2% (40/180) and 19.8% (19/96), respectively (chi(2) = 0.220, P = 0.639). TTV DNA positive rates of patients with hepatitis A, B, C, E and non-A to E were 20.0% (6/30), 16.7% (5/30), 23.3% (7/30), 36.7% (11/30) and 18.3% (11/60), respectively. Of 40 TTV DNA positive patients, 20 (50.0%) were TTV G1, 7 (17.5%) TTV G2, 10 (25.0%) coinfected with different genotypes of TTV, and 3 untyped by HMA. Twenty G1 and 7 G2 detected by HMA were confirmed by sequence analysis. Of 10 patients coinfected with different genotypes of TTV, 5 were G1 and G2, 2 G1 and G3, 1 G1 and G4, 1 G1 and G3, and 1 with G1, G2 and G3 coinfections. CONCLUSION: HMA was recognized as simple, sensitive, specific and less-costly, thus could be used for genotyping of TTV.

Application of Molecular Adsorbents Recirculating System to remove NO and cytokines in severe liver failure patients with multiple organ dysfunction syndrome.

BACKGROUND: Molecular Adsorbents Recirculating System (MARS) is a new promising artificial liver support therapy, the aim of this study was to assess the effectiveness of MARS to remove nitrous oxide (NO) and cytokines in severe liver failure patients with multiple organ dysfunction syndrome (MODS). METHODS: Sixty single MARS treatments were performed with length of 6-24 h on 24 severe liver failure patients (18 males/6 females) with MODS. RESULTS: The MARS therapy was associated with a significant removal of NO and certain cytokines such as TNF-alpha, IL-6, IL-8, and INF-gamma, together with marked reduction of other non-water-soluble albumin bound toxins and water-soluble toxins, these were associated with a improvement of the patients' clinical conditions including hepatic encephalopathy, deranged hemodynamic situation and as well as renal and respiratory function, thus resulted into marked decrease of Sequential Organ Failure Assessment (SOFA) score and improved outcome: nine patients were able to be discharged from the hospital or bridged to successful liver transplantation, the overall survival of 24 patients was 37.5%. CONCLUSION: We can confirm the positive therapeutic impact and safety to use MARS on liver failure patients with MODS associated with elevated levels of NO and cytokines.

[The treatment of molecular adsorbents recirculating system artificial liver in severe liver failure patients with multiple organ dysfunction syndrome].

OBJECTIVE: To evaluate the effectiveness and mechanisms of molecular adsorbents recirculating system (MARS) treatment in severe liver failure patients with multiple organ dysfunction syndrome (MODS). METHODS: 60 single MARS treatments were performed for 6 - 24 hours on 24 severe liver failure patients with MODS. RESULTS: MARS therapy was associated with marked reduction of albumin bound toxins and water soluble toxins, together with a significant removal of NO and certain cytokines, such as TNF-alpha, IL-6, IL-8, and INF-gamma. These were associated with a improvement of the patients' clinical conditions including hepatic encephalopathy, deranged hemodynamic situation, as well as renal and respiratory function, thus resulted into marked decrease of sequential organ failure assessment (SOFA) score (from 9.72+-1.89 to 6.98+-2.34), and improving outcome: 9 patients were able to be discharged from the hospital or bridged to successful liver transplantation. The overall survival rate of 24 patients was 37.5%. CONCLUSIONS: There is positive therapeutic impact and safety to use MARS on liver failure patients with MODS. The effectiveness of MARS is correlated with reducing the levels of NO and cytokines, except for completely removing of accumulated toxins in liver failure patients.

[Detection of SEN virus in sera of patients with chronic hepatitis B and general population in 5 cities of China].

OBJECTIVE: To study the prevalence of SEN virus (SENV) infection in CHB patients in five cities of China. METHODS: A nest-polymerase chain reaction (nPCR) was used for detection of SENV-D and SENV-H in sera of 595 CHB patients from 5 cities of China and 96 normal individuals from Beijing. A total of 7 SENV strains were analyzed by direct sequencing. RESULTS: The prevalence rates of SENV in CHB patients and normal individuals were 61.3% and 62.5%, respectively (chi(2) = 0.047, P = 0.829). The prevalence rates of CHB patients between 5 cities were different. Nucleotide sequence analysis showed that the homology between 4 SENV-D strains was 91% - 98% and 95% - 98% between 3 SENV-H strains isolated from 5 cities in China. CONCLUSION: SENV-D/H were prevalent in CHB patients of China and their prevalence rates were similar to that in normal individuals.

[Predictors associated with clinical deterioration in SARS patients].

BACKGROUND: To study the predictive factors associated with clinical deterioration in SARS patients. METHODS: The clinical data of 60 SARS patients were analyzed by logistic regression and Cox's proportional hazards analysis. RESULTS: In logistic regression models, both older age (P=0.009) and severe lymphopenia (P=0.004) were significant predictors of clinical deterioration. In Cox's proportional hazard models, severe lymphopenia was significant predictor associated with prolongation of stay in hospital. CONCLUSION: Older age and severe lymphopenia seem to be statistically significant for predicting the clinical deterioration in SARS patients.