Investigation of Single-stranded Deoxyribonucleic Acid Translocation Through α-Hemolysin Nanopore with Ionic Liquid Supporting Electrolytes / 分析化学

Due to the difference in spatial configuration and charge of the bases in a DNA molecule, characteristic translocation current pulses through a single nanopore could be obtained. This could become the basis of DNA sequencing method. However, due to the fast translocation speed (sub-micro seconds) and the small current change (about pA), it is still a challenge to obtain the accurate molecular substructure with present electronic techniques. In this work, in order to control the translocation behavior of ssDNA, two kinds of ionic liquids with high viscosity and conductivity were introduced to establish a viscosity gradient with the α-hemolysin single nanopore interface and the acidity of the solution was optimized. The trans chamber contained pure BmimPF6 and the cis chamber contained 1 mol/ L BmimCl and 10 mmol/ L Tris-HCl ( pH 5. 5 ). Preliminary experiment results under this electrolyte configuration showed that poly ( dC) 15 , poly ( dC) 15 , poly(dC) 30 and poly(dC) 50 exhibited obvious long duration pulses with high current suppression ratio. The blocking depth reached more than 95％ of long blocking events. The duration time of long blocking events prolonged to tens or hundreds of milliseconds. Meanwhile, the peak-peak of baseline noise was reduced by about 30％ .

Study on Interaction of Protamine and Single-stranded DNA by Current Pulses Through Single Nanopore / 分析化学

Single nanopore current pulse method is a new, rapid and simple detection method, which is promising for single-molecule DNA sequencing and bio-sensing. Due to the short duration and the low current amplitude of the pulses caused by molecular translocation under normal conditions, pulse detection system with fast response and high sensitivity is required. In this work, based on a lab-established pulse detection system, the effect of protamine in the regulation of single-stranded (ssDNA) current pulses with α-hemolysin (α-HL) single nanopore interface was investigated. Experimental results showed that the pulses positive charged protamine and negative ssDNA probes were both well observed with the established system, and both the pulse amplitude and duration of ssDNA were increased as a result of interaction with protamine. This study provides a way to improve the resolving power of current pulses based on molecular interactions.

Reduced zinc concentration in expressed prostatic secretion relates to the pain symptoms of types Ⅲ and Ⅳ prostatitis / 中华男科学杂志

<p><b>Objective</b>To determine the zinc levels in the expressed prostatic secretion (EPS) of the patients with different types of chronic nonbacterial prostatitis, and explore the reference value of zinc concentration in EPS in the diagnosis and treatment of prostatitis.</p><p><b>METHODS</b>We collected EPS samples from 35 healthy men and 173 patients with chronic nonbacterial prostatitis, including 65 cases of type ⅢA, 69 cases of type ⅢB, and 39 cases of type Ⅳ, according to the National Institutes of Health Chronic Prostatitis Symptom Index (NIH-CPSI). We compared the zinc levels in the EPS samples among different groups and analyzed the correlations of zinc concentration with the NIH-CPSI scores, WBC count, pH value, and age of the subjects.</p><p><b>RESULTS</b>The participants were aged 17－65 (32.5±8.5) years. The zinc concentrations in the EPS were significantly lower in the ⅢA (［162.2±10.8］ μg/ml) and ⅢB (［171.2±12.0］ μg/ml) than in the Ⅳ (［234.6±17.9］ μg/ml) (P<0.05 ) and the control group (［259.5±14.6］ μg/ml) (P<0.05 ). The zinc level was correlated negatively with the NIH-CPSI pain score (r=－0.248, P<0.01), quality of life score (r=－0.232, P<0.01), severity score (r=－0.270, P<0.01), total NIH-CPSI score (r=－0.281, P<0.01), and the pH value in EPS (r=－0.208, P<0.01), but showed no correlation with the WBC count and age of the subjects.</p><p><b>CONCLUSIONS</b>The reduced zinc concentration in the EPS of the patients with chronic nonbacterial prostatitis may be associated with the pain symptoms of the disease, which suggests the potential reference value of measuring the zinc concentration in EPS in the diagnosis and treatment of prostatitis.</p>

Low-dose daily de-escalatory administration of tadalafil for psychological erectile dysfunction / 中华男科学杂志

<p><b>OBJECTIVE</b>To investigate the effect of low-dose daily de-escalatory administration of tadalafil on psychological erectile dysfunction (ED).</p><p><b>METHODS</b>We randomized 84 psychological ED patients into an observation and a control group of equal number to receive low-dose daily de-escalatory administration and on-demand medication of tadalafil, respectively, both for 2 months. We compared the scores on IIEF-5 and erection hardness (EHS) between the two groups before and after the treatment.</p><p><b>RESULTS</b>The treatment and follow-up were accomplished for 79 cases, with 5 withdrawals in the control group. The IIEF-5 and EHS scores were remarkably improved in both the observation and control groups after treatment. The rate of therapeutic effectiveness was significantly higher in the observation group than in the control (95.2% vs 86.5%, P < 0.05).</p><p><b>CONCLUSION</b>Low-dose daily de-escalatory administration of tadalafil is highly effective and even better than on-demand medication of tadalafil for psychological ED.</p>

Low-dose testosterone undecanoate capsules combined with tadalafil for late-onset hypogonadism accompanied with ED / 中华男科学杂志

<p><b>OBJECTIVE</b>To observe the clinical effect of low-dose testosterone undecanoate capsules combined with tadalafil on late-onset hypogonadism (LOH) accompanied with ED.</p><p><b>METHODS</b>Ninety cases of LOH accompanied with ED who met the inclusion criteria were randomly divided into a control group and a combination therapy group, the former treated with tadalafil and the latter with low-dose testosterone undecanoate capsules combined with tadalafil. The LOH symptoms, IIEF-5 scores, sexual encounter profile (SEP) scores, prostate volumes, and the levels of total testosterone (TT), free testosterone (FT) and prostatic specific antigen (PSA) were recorded and compared between the two groups before and after treatment.</p><p><b>RESULTS</b>The IIEF-5 and SEP scores and the TT and FT levels were 20.6 +/- 3.8, 4.02 +/- 1.08, (15.4 +/- 3.4) nmol/L and (0.391 +/- 0.062) nmol/L, respectively, in the combination therapy group after treatment, significantly higher both than 15.7 +/- 3.9, 1.49 +/- 0.82, (10.1 +/- 1.2) nmol/L and (0.200 +/- 0.045) nmol/L before treatment (P < 0.01) and than 8.6 +/- 3.6, 3.50 +/- 1.21, (10.2 +/- 1.2) nmol/L and (0.210 +/- 0.051) nmol/L in the control group after treatment (P < 0.01).</p><p><b>CONCLUSION</b>Low-dose testosterone undecanoate capsules combined with tadalafil has a definite clinical effect and no obvious adverse reactions in the treatment of LOH accompanied with ED.</p>

Combination of compound Xuanju capsule and tamoxifen citrate for idiopathic oligozoospermia / 中华男科学杂志

<p><b>OBJECTIVE</b>To evaluate the clinical effects of Compound Xuanju Capsule combined with tamoxifen citrate on the seminal parameters of men with idiopathic oligozoospermia.</p><p><b>METHODS</b>We equally assigned 120 men with idiopathic oligozoospermia to receive Compound Xuanju Capsule plus tamoxifen citrate (experiment group) or tamoxifen citrate alone (control group). After 3 months of medication, we compared the concentration and total number of sperm with the baseline, and analyzed the influence of the duration of natural infertility on the therapeutic effect.</p><p><b>RESULTS</b>Both the concentration and total number of sperm were significantly increased in both the experiment and the control groups after 3 months of medication as compared with the baseline (P < 0.05), and the increases were even more significant in the former than in the latter group (P < 0.05). The therapeutic efficacy was remarkably better in the patients with natural infertility < or = years than in those > 3 years (P < 0.05).</p><p><b>CONCLUSION</b>Compound Xuanju Capsule combined with tamoxifen citrate produces satisfactory results in the treatment of idiopathic oligozoospermia, and therefore can be used as a first-line therapy for this disease.</p>

Endoscopic surgery for 89 cases of nasal inverted papilloma / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To evaluate the effect of endoscopic surgery for nasal inverted papilloma.</p><p><b>METHODS</b>The clinical data of 89 patients treated with endoscopic surgery in our department from May 2003 to May 2008 were retrospectively analysed. The clinical classification was assessed by preoperative endoscopy and CT or MRI. All cases were routinely followed up from 1 to 5 years.</p><p><b>RESULTS</b>The recurrence rates in group of endoscopic management and group of endoscopic plus Caldwell-Luc management were 12.5% and 11.8% respectively (chi(2) = 0.007, P > 0.05). The recurrence rates in group of grade I, grade II and group of grade III patients were 9.1% (5/55), 17.2% (5/29) and 20% (1/5) respectively (P > 0.05). The recurrence rate in the two times operation group (27.3%) was significantly higher than that in the one time group (7.5%, chi(2) = 4.311, P < 0.05). There were 70 lesions certified to be resected completely, six of these patients (8.6%) recurred. Nineteen lesions were certified to be resected uncompletely, five of these patients (26.3%) recurred. The difference was no significant (chi(2) = 2.860, P = 0.09).</p><p><b>CONCLUSIONS</b>The endoscopic surgery in nasal inverted papillomas was an effective method with minimally invasiveness, but it still had a high recurrence. The pathological examine of surgical margin could partially judge the prognosis.</p>

Correlation analysis of two serum specific IgE test systems and skin prick test in allergic rhinitis patients / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To evaluate the correlation between two serum specific IgE and skin prick test (SPT) for the diagnosis of allergic rhinitis.</p><p><b>METHODS</b>Two hundred and sixteen patients were referred to the allergist for a suspected allergic rhinitis between June and October in 2009. Patients were classified as positive for inhalant allergy if they had a positive clinical history and a related positive SPT for the suspected inhalant allergen. Statistical analysis was performed using SPSS13.0 software.</p><p><b>RESULTS</b>One hundred and fifty-eight patients had a positive SPT, comparing with the SPT, the diagnostic indexes (accuracy, sensitivity, specificity) of the ImmunoCAP system and the AllergyScreen system were 0.810 and 0.819, 0.872 and 0.780, 0.741 and 0.862 respectively. The accuracy was similar between the two systems (χ(2) = 0.112, P > 0.05). The ImmunoCAP system had a higher sensitivity (χ(2) = 7.361, P < 0.05). The AllergyScreen system had a higher specificity (χ(2) = 10.222, P < 0.05).</p><p><b>CONCLUSIONS</b>This data supported the use of ImmunoCAP system and AllergyScreen system to identify potentially significant individual allergens in the diagnosis of allergic rhinitis. The ImmunoCAP system had a higher sensitivity. The AllergyScreen system had a higher specificity. The AllergyScreen system can be used as a complementary with the ImmunoCAP system.</p>

Calcium overload is a critical step in programmed necrosis of ARPE-19 cells induced by high-concentration H₂O₂ / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>Oxidative stress plays an important role in retinal pigmental epithelium (RPE) death during aging and the development of age-related macular degeneration. Although early reports indicate that reactive oxygen species (ROS) including H₂O₂ can trigger apoptosis at lower concentrations and necrosis at higher concentrations, the exact molecular mechanism of RPE death is still unclear. The purpose of this study was to investigate the molecular pathways involved in RPE death induced by exogenous ROS, especially at higher concentrations.</p><p><b>METHODS</b>Cultured ARPE-19 cells were treated with H₂O₂ at different concentrations and cell viability was measured with the MTT assay. Cell death was morphologically studied by microscopy using APOPercentage assay and PI staining. Furthermore, the impact of oxidative stress on ARPE-19 cells was assessed by HO-1 and PARP-1 Western blotting and by the protection of antioxidant EGCG. Calcium influx was determined using the fura-2 calcium indicator and the role of intracellular calcium overload in ARPE-19 cell death was evaluated following cobalt treatment to block calcium effects.</p><p><b>RESULTS</b>H₂O₂ reduced the viability of ARPE-19 cells in a concentration-dependent manner, which was presented as a typical s-shaped curve. Cell death caused by high concentrations of H₂O₂ was confirmed to be programmed necrosis. Morphologically, dying ARPE-19 cells were extremely swollen and lost the integrity of their plasma membrane, positively detected with APOPercentage assay and PI staining. 24-hour treatment with 500 μmol/L H₂O₂ induced remarkable up-regulation of HO-1 and PARP-1 in ARPE-19 cells. Moreover, antioxidant treatment using EGCG effectively protected cells from H₂O₂-induced injury, increasing cell viability from 14.17%±2.31% to 85.77%±4.58%. After H₂O₂ treatment, intracellular calcium levels were highly elevated with a maximum concentration of 1200 nM. Significantly, the calcium channel inhibitor cobalt was able to blunt this calcium influx and blocked the necrotic pathway, rescuing the ARPE-19 cell from H₂O₂-induced death.</p><p><b>CONCLUSIONS</b>At high concentrations, H₂O₂ induces ARPE-19 cell death through a regulated necrotic pathway with calcium overload as a critical step in the cell death program.</p>

Jinleng undershorts palliates varicocele / 中华男科学杂志

<p><b>OBJECTIVE</b>To investigate the effect of Jinleng undershorts on the elevated scrotal temperature induced by varicocele as well as on other clinical symptoms of the disease.</p><p><b>METHODS</b>Fifty-one varicocele patients received the treatment of wearing Jinleng undershorts for 30 min twice a day for a course of 90 days. Comparisons were made between the scrotal temperatures and other clinical symptoms of varicocele before and after the treatment.</p><p><b>RESULTS</b>After 90 days of treatment with Jinleng undershorts, the left scrotal temperature of the varicocele patients was significantly reduced from (32.16 +/- 0.79) degrees C to (31.53 +/- 0.77) degrees C (P < 0.01), and the right scrotal temperature decreased from (31.91 +/- 0.73) degrees C to (31.81 +/- 0.63) degrees C (P > 0.05). Compared with pretreatment, significant improvement was found in such symptoms as wetness, fever and swelling of the scrotum, backache, headache, dizziness, fatigue and anxiety (P < 0.05), as well as in testicular pain (P < 0.01) and IIEF-5 score, which was increased from 15.89 +/- 6.13 to 20.04 +/- 3.87 (P < 0.01).</p><p><b>CONCLUSION</b>Jinleng undershorts can be used for the treatment of mild and moderate varicocele.</p>

Atypical magnetic resonance imaging vs pathological findings of leiomyoma in the female reproductive system / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate magnetic resonance imaging (MRI) findings of the atypical leiomyoma in the female reproductive system in comparison with the pathological features of the neoplasms.</p><p><b>METHODS</b>A retrospective analysis of the MRI findings and the pathological features was conducted in 24 cases of atypical leiomyoma involving the female reproductive system.</p><p><b>RESULTS</b>Atypical leiomyomas were displayed by MRI as solid tumor mass surrounded by cystic degeneration, pseudotumors, or solid mass with homogeneous signal intensity. Intrauterine lesions were found in 19 cases, involving the subserosal layer (n=11), intramural region (n=4), broad ligament (n=3), cervix (n=2), submucous layer (n=2), vagina (n=1), and the ovary (n=1). Except for two cases with submucous lesions shown as solid mass, all the cases had lesions appearing as solid cystic mass, whose solid part showed hypo or isointense signals on T1WI and moderate hyperintense signals on T2WI, with heterogeneous enhancement after contrast agent injection. Tumor cell and interstitial cell swelling, vascular hyalinosis, hyalinosis, myxoedema, cystic degeneration, and hemorrhage were found in the lesions.</p><p><b>CONCLUSION</b>Leiomyoma can occur at almost any site in the female reproductive system, and atypical leiomyoma usually are shown as solid cystic mixed mass in the pelvic cavity. Evaluation of the relationship between the solid mass and cystic portion and observation for the presence of low signal on T2WI may help in the diagnosis of atypical leiomyoma.</p>

Identification of a functional ITAM-like sequence within G1 cytoplasmic tail of Hantaan virus / 病毒学报

The G1 cytoplasmic tail of Hantaan virus (HTNV) harbors a highly conserved region, which is homologous to immunoreceptor tyrosine-based activation motifs (ITAM) and is termed the ITAM-like sequence. To demonstrate the potential signal-transducing activity of G1 ITAM-like sequence resembling the canonical ITAM within immune and endothelial cells, a series of experiments were performed to define its interaction with cellular kinases. The synthesized G1 ITAM-like peptide was shown to coprecipitate with cellular phosphoprotein complexes by an immune-complex kinase assay. Mutational analyses showed that this ITAM-like sequence was a substrate for the Src family kinase Fyn, and two conserved tyrosine residues were required for coprecipitating Lyn, Syk, and ZAP-70 kinases. These findings demonstrated that HTNV envelope glycoprotein G1 contains a functional ITAM-like sequence in its cytoplasmic tail, which can bind critical cellular kinases that regulate immune and endothelial cell functions.

The role of insulin-like growth factor-2 gene differentially methylated regions in TCDD-induced malformation / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To study the effects of 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD) on the development of fetal rats and to explore the relationship between TCDD-induced abnormal development in rats and the expression and the methylation of insulin-like growth factor 2 gene (Igf2).</p><p><b>METHODS</b>A single dose of 10 microg/kg TCDD was given to gestation day (GD) 10 pregnant rats by gavage. On GD20, the fetuses were taken out and examined. The crown-rump length, the body weight and the placental weight were measured. The expression of Igf2 in liver was detected by real-time quantitative reverse transcription (RT-PCR) and Western blot. The methylation of Igf2 differentially methylated regions (DMRs) in liver was analyzed by a methylation-sensitive restriction enzyme Hpa II PCR assay and a bisulfite-modified DNA sequencing procedure.</p><p><b>RESULTS</b>In the treatment group, 12.2% of the fetuses were either dead or absorbed, and 11.6% of them were malformed. For the live fetuses, their crown-rump length, body weight and placental weight were significantly lower than those of the control group. The relative amount of Igf2 mRNA in the treated livers and the control livers was 0.77 +/- 0.11 and 0.27+/- 0.15, respectively. The number was significantly higher in the treatment group than in the control group (P < 0.01). Western blot also showed a remarkable up regulation of Igf2 protein in liver after treatment. The two groups showed no difference in the methylation status of Igf2 DMR1 in liver. The DMR2 Igf2 was significantly hypomethylated in the treated livers than in the control livers.</p><p><b>CONCLUSION</b>Exposure to TCDD in pregnancy can lead fetal rats to death, absorption, malformation and intrauterine growth retardation (IUGR). The TCDD led abnormal development in rats may be associated with the hypomethylated DMR2 of Igf2 and the up regulation of Igf2 in liver.</p>

Correlation analysis and identification of G421C in regulatory region of CYP4F2 gene with essential hypertension / 中国医学科学院学报

<p><b>OBJECTIVE</b>To investigate the correlation between G421C polymorphism in the regulatory region of CYP4F2 gene and essential hypertension and its molecular mechanism.</p><p><b>METHODS</b>Totally 196 hypertensive patients (hypertension group) and 219 normotensive subjects (control group) were genotyped by polymerase chain reaction-restriction fragment length polymorphism. The promoter activity with different alleles was evaluated by reporter assay. A Myb responsive element was identified using gel retardation assay.</p><p><b>RESULTS</b>Significant differences were found in distribution of genotype and allele frequency of G421C between hypertension group and control group (P < 0.05), and homozygous GG genotype was independently associated with hypertension after adjustment for age, gender, body mass index, and other risk factors (odds ratios 1.87, 95% CI 1.11-3.13, P < 0.05). 421G reporter construct showed decreased promoter activity compared with 421C reporter construct. 421G existed in Myb responsive element, whereas 421C damaged this motif.</p><p><b>CONCLUSION</b>G421C polymorphism in the regulatory region of CYP4F2 gene is correlated with essential hypertension. 421G allele inhibits transcription by binding affinity of Myb responsive element.</p>

The construction and primary screening of a phage display library of HCV C and E1 genes evolved with an artificial pattern / 中华肝脏病杂志

<p><b>OBJECTIVES</b>To construct and screen a primarily phage display library of HCV C and E1 genes evolved with an artificial pattern.</p><p><b>METHODS</b>Two genes of about 1 kb with different genotypes were evolved by DNA shuffling. The re-assembled HCV C and E1 genes were cloned into a phage vector. After being rescued with helper phage M13KO7, a phage display library was constructed. Then the library was screened with anti-C and E1 McAb. Double-antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) was carried out on twenty individual phage clones selected randomly to detect their binding and reactive activity with high-titer HCV-positive sera. Normal sera were used as controls.</p><p><b>RESULTS</b>The phage display library of HCV C and E1 genes which evolved with an artificial pattern was constructed. Their capacity amounted to 1.64 x 10(6), and 86 percent of the clones contained C and E1 genes. After four rounds of panning, the phage library was specifically enriched. Twelve positive clones were successfully screened.</p><p><b>CONCLUSION</b>The capacity and diversity of the constructed library are enough for screening. The results demonstrate the superiority of the specific binding and reactive activity and affinity of the 12 phage clones from the HCV positive sera.</p>

Inhibition of vascular endothelial growth factor gene expression by T7-siRNAs in cultured human retinal pigment epithelial cells / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Retinal pigment epithelial (RPE) cells play an important role in the occurrence of choroidal neovascularization (CNV). Vascular endothelial growth factor (VEGF) as a positive regulatory growth factor is produced by the RPE in an autocrine or paracrine manner, promoting CNV development. Duplexes of 21 nt RNAs, known as short interfering RNAs (siRNAs), efficiently inhibit gene expression by RNA interference when introduced into mammalian cells. We searched for an efficient siRNA to interfere with VEGF expression in RPE cells and shed light on the treatment of CNV.</p><p><b>METHODS</b>Human primary RPE (hRPE) cells were cultured and identified. Three pairs of siRNAs were designed according to the sequence of VEGF 1-5 extrons and synthesized by T7 RNA polymerase transcription in vitro. To evaluate the inhibitory activity of T7-siRNAs, hRPE cells were transfected via siPORT Amine. The interfering effect of T7-siRNAs in hRPE cells was examined by semiquantitative reverse transcription-polymerase chain reaction and immunofluorescence.</p><p><b>RESULTS</b>Three pairs of T7-siRNAs synthesized by in vitro transcription with T7 RNA polymerase suppressed VEGF gene expression with efficiency from 65% to 90%. T7-siRNA (B), targeted region at 207 nt to 228 nt and double stranded for 21 nt with 2 nt UU 3' overhangs, was the most effective sequence tested for inhibition of VEGF expression in hRPE cells. Compared with nontransfected cells, the mean fluorescence in hRPE cells transfected with T7-sRNAs was significantly less (P < 0.01). siRNA with a single-base mismatch and ssRNA(+) did not show suppressing effect. Furthermore, it was found that siRNAs had a dose dependent inhibitory effect (5 to 10 pmol).</p><p><b>CONCLUSION</b>T7-siRNA can effectively and specifically suppress VEGF expression in hRPE cells and may be a new way to treat CNV.</p>