Integration of piezo-capacitive and piezo-electric nanoweb based pressure sensors for imaging of static and dynamic pressure distribution

Recently, highly flexible and soft pressure distribution imaging sensor is in great demand for tactile sensing, gait analysis, ubiquitous life-care based on activity recognition, and therapeutics. In this study, we integrate the piezo-capacitive and piezo-electric nanowebs with the conductive fabric sheets for detecting static and dynamic pressure distributions on a large sensing area. Electrical impedance tomography (EIT) and electric source imaging are applied for reconstructing pressure distribution images from measured current-voltage data on the boundary of the hybrid fabric sensor. We evaluated the piezo-capacitive nanoweb sensor, piezo-electric nanoweb sensor, and hybrid fabric sensor. The results show the feasibility of static and dynamic pressure distribution imaging from the boundary measurements of the fabric sensors.

Analysis and comparison of the cost-effectiveness of statins according to the baseline low-density lipoprotein cholesterol level in Korea

WHAT IS KNOWN AND OBJECTIVE

There are a few Korean studies on the economics of statins based on reduction in low-density lipoprotein cholesterol (LDL-C) data from other countries. This study aimed to analyse and compare the cost-effectiveness of statins according to the baseline LDL-C level in Korea.

METHODS

Between January 2009 and December 2015, the data of patients who were prescribed statins for the first time were extracted from electronic medical records. We performed a cost-effectiveness analysis (CEA) based on the LDL-C reduction rate (CEA-RR) and target achievement rate.

RESULTS AND DISCUSSION

Among high-intensity statins, the CEA-RR value of rosuvastatin (20 mg) was significantly lower than that of atorvastatin (40 mg) at all baseline LDL-C levels, except levels of 160-189 mg/dL. Additionally, at baseline LDL-C levels of 130-159 mg/dL, the CEA-RR value of rosuvastatin (20 mg) was three times lower than that of atorvastatin (40 mg) (9·1 ± 2·5 $/% vs. 31·7 ± 15·0 $/%, P < 0·001). Among moderate-to-low-intensity statins, rosuvastatin (5 mg) showed the lowest CEA-RR value (4·0 ± 0·6 $/%), and the value significantly increased for pitavastatin (2 mg) (8·0 ± 0·6 $/%), atorvastatin (10 mg) (9·5 ± 0·5 $/%), simvastatin (10·8 ± 1·1 $/%) and pravastatin (40 mg) (11·5 ± 0·9 $/%) in order (P < 0·0001). On changing from atorvastatin (10 mg) to atorvastatin (20 mg), the additional yearly cost was 16·0 and additional CEA-RR value was 2·74 $/%. On the other hand, on changing from atorvastatin (10 mg) to rosuvastatin (10 mg), the additional yearly cost was -16·3 and additional CEA-RR value was -1·8 $/%.

WHAT IS NEW AND CONCLUSION

We successfully compared the cost-effectiveness of statins according to the baseline LDL-C level in Korea. It is expected that our findings will help clinical decision-making with regard to statin prescription, and this will help reduce national medical expenditure.

Abstract P6-05-05: The expression of lysyl oxidase and fibrotic focus is related to inflammation in breast cancer

Background: Lysyl oxidase (LOX) is an extracellular matrix enzyme that catalyzes the

cross-linking of collagens or elastin. Our hypothesis is that LOX contributes to the formation

of a fibrotic focus (FF), which is related to inflammation in breast carcinogenesis.

In this study, we analyzed the association between the expression LOXs and FF, and

investigated prognostic significance in breast cancer.

Methods: Tissue microarrarys were constructed from the specimens of 444 patients

with primary invasive breast cancer. Immunohistochemical staining for LOX, LOXlike

(LOXL)-, LOXL-2 and LOXL-3 was performed. The status of FF within the tumor

was assessed. The number of CD4+ T cells, CD8+ T cells, CD68+ macrophages was

counted, and intratumoral and peritumoral lymphocyte infiltration were evaluated.

The clinicopathologic characteristics of the patients were analyzed.

Result: The percentage of positive FF was 39.2% and positive rate of LOX expression

was 50% in primary breast cancer tissues. FF was found to be significantly associated

with intratumoral and peritumoral inflammation, lymph node metastasis, high histologic

grade, larger tumor size. LOX was associated with intratumoral and peritumoral

inflammation, CD8+ T cells and menopausal status. LOXL-3 was significantly associated

with positive expression of ER and PR, and molecular subtype.

Conclusions: FF and the expression of LOX were associated with inflammation in

breast cancer in this study. Our results suggest that LOXs may contribute to the formation

of a FF indirectly in relation with inflammation in breast cancer. Further studies

are needed to clarify the role of LOXs, FF and inflammation in tumorigenesis and

prognostic value of them in breast cancer.

Citation Format: Park SH, Jeong YJ, Bong JG, Oh HK. The expression of lysyl oxidase and fibrotic focus is related to inflammation in breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P6-05-05.

Comparative analysis of the efficacy of omega-3 fatty acids for hypertriglyceridaemia management in Korea

WHAT IS KNOWN AND OBJECTIVE

This study aimed to compare the ability of statin monotherapy (ST group), omega-3 fatty acid monotherapy (OM_A group) and combination therapy with omega-3 fatty acids and a statin (OM_S group), to reduce triglyceride (TG) levels in patients with hypertriglyceridaemia.

METHODS

In this retrospective cohort study, we extracted data from the electronic medical records of patients initially prescribed either a statin or omega-3 fatty acids between January, 2009 and December, 2013. We performed a comparative analysis of the change in cholesterol levels between baseline and an average of 3 months later.

RESULTS AND DISCUSSION

Data were extracted for 2071 patients. The average daily eicosapentaenoic acid (EPA) ethyl ester and docosahexaenoic acid (DHA) ethyl ester intake was 1689 mg, and 79-86% of the OM_A and OM_S groups were prescribed two omega-3 fatty acid capsules. At a baseline TG level of between 200 and 500 mg/dL, TG levels were reduced by 16 ± 2·8% in the ST group, 28 ± 2·8% in the OM_A group and 29 ± 2·3% in the OM_S group (P = 0·001 for ST group vs. OM_A and OM_S groups), with no difference between the OM_A and OM_S groups. At a baseline TG level ≥500 mg/dL, there was no difference in TG level reduction between the three groups (54 ± 7·3%, 55·8 ± 3·5% and 51·8 ± 6·8%, respectively, P = 0·851).

WHAT IS NEW AND CONCLUSION

Although omega-3 fatty acids are not considered the primary medication for hypertriglyceridaemia, the prescription of omega-3 fatty acids is justifiable if reduction in TG levels is judged to be necessary.

Highly precise nanofiber web-based dry electrodes for vital signal monitoring

Dry electrodes have been prepared through silver-plating elastic TPU and SBS electrospun nanofiber webs to improve electrode accuracy. The results revealed that the new dry electrodes can exhibit performance comparable to Ag/AgCl gel electrode.

Predictors for the progression of geographic atrophy in patients with age-related macular degeneration: fundus autofluorescence study with modified fundus camera

PURPOSE

We examined the association between abnormal fundus autofluorescence (FAF) features on images obtained by a modified fundus camera (mFC) and geographic atrophy (GA) progression in patients with age-related macular degeneration (AMD).

METHODS

Serial FAF images of 131 eyes from 131 patients with GA were included in the study. All FAF images were obtained with an mFC (excitation, ∼ 500-610 nm; emission, ∼ 675-715 nm). The GA area was quantified at baseline and 1 year later using a customized segmentation program. The yearly GA enlargement rate was then calculated. Abnormal FAF patterns in the junctional zone of GA were classified as None or Minimal change, Focal, Patchy, Banded, or Diffuse according to previously published classification based on confocal scanning laser ophthalmoscopy (cSLO). The relationship between GA enlargement and abnormal FAF was evaluated.

RESULTS

The mean rate of GA enlargement was the fastest in eyes with Diffuse pattern (1.74 mm(2) per year), followed by eyes with the Banded pattern (1.69 mm(2) per year). Binary logistic regression analysis revealed that eyes with the Banded and Diffuse pattern had significantly higher risk for GA enlargement compared with eyes with the other patterns.

CONCLUSIONS

FAF image obtained by mFC appears to be acceptable for evaluating GA in accordance with an established cSLO-based classification. Eyes with the Banded or the Diffuse patterns of abnormal FAF at baseline indicate a high risk for GA progression. Identifying patients at high risk for GA progression using an mFC is broadly available method that can provide additional information to help predict disease course.

Abstract P2-06-05: Association of promoter methylation status of the FHIT gene and Fhit expression with HER2/neu status in breast cancer

Purpose: Aberrant DNA methylation has been recognized to contribute to breast carcinogenesis, and promoter hypermethylation of many tumor suppressor genes has been correlated with decreased gene expression. The fragile histidine triad (FHIT) gene is a putative tumor suppressor gene in breast and other cancers, and loss of Fhit expression has been observed in breast cancers. The aim of this study was to evaluate the association between methylation of the FHIT gene and its expression in breast cancer, and to investigate whether methylation and expression of the FHIT gene would correlate with clinicopathological characteristics in relation to human epidermal growth factor receptor 2 (HER2) status.

Methods: Pyrosequencing of bisulfite treated DNA was performed to study the methylation status of the FHIT gene in 60 breast cancer samples from Korean women obtained at Daegu Catholic University Hospital. We examined the expression of FHIT using tissue microarrays by immunohistochemical staining. Association between the methylation status of the FHIT gene and its expression was analyzed, and the relationship between the FHIT expression and the clinicopathological characteristics of the patients was evaluated.

Results: FHIT methylation was detected in 96.7% and positive expression rate of Fhit was 87.3% of the patients. The mean methylation level of the FHIT gene was associated with intratumoral inflammation. Methylation level of the FHIT gene had no significant differences according to molecular subtypes. Loss of Fhit expression was associated with large tumor size, basal-like subtype and positive expression of EGFR. In HER2-negative breast cancers, loss of Fhit expression was significantly associated with tumor size, estrogen receptor status and Ki-67 proliferation index. There was no significant correlation between methylation of the FHIT gene and its expression in this study.

Conslusion: Our study revealed that loss of Fhit expression in breast cancer is associated with poor prognostic features, although there is no significance association between the FHIT gene methylation and Fhit expression. We found that in HER2-negatvie breast cancers, loss of Fhit expression was associated with poor prognostic features. These results support the possibility of potential complementation between HER2 and the Fhit pathway. The clinical significance of our findings needs to be further evaluated in larger cohorts with longer follow-up.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-06-05.

Comparison of chest digital tomosynthesis and chest radiography for detection of asbestos-related pleuropulmonary disease

AIM

To compare chest digital tomosynthesis (DTS) with digital radiography for the detection of asbestos-related pleuropulmonary disease.

MATERIALS AND METHODS

The institutional review board approved this study and all participants gave informed consent. Forty-five participants with a history of asbestos exposure were examined with DTS and radiography. Low-dose multidetector computed tomography (CT) in the prone position served as the reference. Two observers evaluated all images for the presence of pleural abnormalities and asbestosis. Interobserver agreement was analysed by using the k statistic. Diagnostic performance of the two imaging methods was compared using McNemar's test.

RESULTS

Interobserver agreement regarding DTS findings was moderate to very good (k = 0.544-0.846) and superior to the radiographic findings (k = 0.236-1.000). Overall, the diagnostic accuracy of DTS for the lesion detection was significantly better than with radiography (all p < 0.05, except that for the comparison of diagnostic accuracy of DTS versus radiographic detection of left diaphragmatic plaques and asbestosis). DTS was more sensitive than radiography for the detection of asbestosis (82% versus 27%, p = 0.031).

CONCLUSION

DTS is more accurate than radiography in the detection of pleural plaques and more sensitive than radiography in the detection of asbestosis. Interobserver agreements with respect to the DTS findings were superior to the radiographic findings.

CT differentiation of pyogenic liver abscesses caused by Klebsiella pneumoniae vs non-Klebsiella pneumoniae

OBJECTIVE

Klebsiella pneumoniae is one of the organisms most commonly isolated from pyogenic liver abscesses in Asian populations. We compared CT findings in liver abscesses caused by K. pneumoniae with those caused by other bacterial pathogens.

METHODS

Of 214 patients with liver abscesses examined over a 5 year period, 129 patients with positive blood or aspirate cultures were enrolled. The patients were divided into two groups: the K. pneumoniae monomicrobial liver abscess (KLA) group (n = 59) and the non-K. pneumoniae monomicrobial or polymicrobial liver abscess (non-KLA) group (n = 70). Two radiologists blinded to the culture results evaluated the CT images, recording the number, size, location and configuration of abscesses, the thickness of the abscess wall, the pattern of rim enhancement, septal enhancement, the double target sign, internal necrotic debris, internal gas bubbles and underlying biliary disease. The presence of diabetes and metastatic infection was also compared between groups. Statistical analyses were performed using univariate (Student's t-test and χ(2) test) and multivariate analyses.

RESULTS

Multivariate analysis showed that a thin wall, necrotic debris, metastatic infection and the absence of underlying biliary disease were the most significant predictors of KLA. When three of the four criteria were used in combination, a specificity of 98.6% was achieved for the diagnosis of KLA.

CONCLUSION

A thin-walled abscess, internal necrotic debris, the presence of metastatic infection and the absence of underlying biliary disease may be useful CT findings in the early diagnosis of K. pneumoniae liver abscesses.

Miliary tuberculosis: a comparison of CT findings in HIV-seropositive and HIV-seronegative patients

The aim of this study was to determine the differences in CT findings of miliary tuberculosis in patients with and without HIV infection. Two radiologists reviewed retrospectively the CT findings of 15 HIV-seropositive and 14 HIV-seronegative patients with miliary tuberculosis. The decisions on the findings were reached by consensus. Statistical analysis was performed using the chi2 test, Mann-Whitney U-test and Fisher's exact test. All of the HIV-seropositive and -seronegative patients had small nodules and micronodules distributed randomly throughout both lungs. HIV-seropositive patients had a higher prevalence of interlobular septal thickening (p = 0.017), necrotic lymph nodes (p = 0.005) and extrathoracic involvement (p = 0.040). The seropositive patients had a lower prevalence of large nodules (p = 0.031). In conclusion, recognition of the differences in the radiological findings between HIV-seropositive and -seronegative patients may help in the establishment of an earlier diagnosis of immune status in patients with miliary tuberculosis.

Dural tears in spinal burst fractures: predictable MR imaging findings

BACKGROUND AND PURPOSE

The diagnosis of traumatic spinal dural tears is difficult to establish. The purpose of this study was to determine the reliable MR imaging findings suggesting dural tears in spinal burst fractures.

MATERIALS AND METHODS

We retrospectively reviewed spine MR images of 21 patients with dural tears (study group) and 33 patients without dural tears (control group), all of whom had spinal burst fractures. The following MR imaging features were compared between the 2 groups: the interpedicular distance, the angle of the retropulsed segments, the ratio of the central canal diameter, the presence or absence of laminar fractures, the degree of laminar fractures, and the extent of epidural hemorrhage.

RESULTS

The mean values of the grade of the laminar fracture, the interpedicular distance, the ratio of the central canal diameter, the angle of the retropulsed segment, and the extent of epidural hemorrhage in the study and control groups were as follows: 1.77 and 0.86 (P = .034), 28.7 and 26 mm (P = .02), 0.37 and 0.58 (P = .008), 112 degrees and 128 degrees (P = .05), and 2.37 and 1.4 (P = .11), respectively. The ratio of the central canal diameter was the most reliable factor suggesting dural tears compared with other factors.

CONCLUSIONS

Dural tears are likely when there are MR imaging findings of laminar fracture of more than grade 1, the interpedicular distance is >28 mm, the central canal ratio is <0.46, and the acute angle of the retropulsed segment is <135 degrees .

Dynamic CT of portal hypertensive gastropathy: significance of transient gastric perfusion defect sign

AIM

To evaluate the "transient gastric perfusion defect" sign as a way of diagnosing portal hypertensive gastropathy (PHG) on multidetector computed tomography (CT).

MATERIALS AND METHODS

Ninety-two consecutive patients with cirrhosis underwent three-phase CT and endoscopy. Endoscopy was performed within 3 days of the CT examination. As controls, 92 patients without clinical evidence of chronic liver diseases who underwent CT and endoscopy were enrolled; the findings at endoscopy were used as a reference standard for patients with PHG. Two radiologists who were unaware of the results of the endoscopy retrospectively interpreted the CT images. PHG was diagnosed on dynamic CT if the transient gastric perfusion defect sign was present. The transient gastric perfusion defect was defined as the presence of transient, segmental or subsegmental hypo-attenuating mucosa in the fundus or body of the stomach on hepatic arterial imaging that returned to normal attenuation on portal venous or equilibrium-phase imaging. The frequency of the transient gastric perfusion defect sign was compared between these two groups using Fisher's exact test. The frequency, sensitivity, specificity, positive predictive values, and negative predictive values of the transient gastric perfusion defect sign were also compared between patients with PHG and without PHG in the cirrhosis group.

RESULTS

Nine patients of 92 patients with cirrhosis were excluded because of previous procedure or motion artifact; the remaining 83 patients with cirrhosis were evaluated. In the cirrhosis group, 40 (48.1%) of 83 patients showed the transient gastric perfusion defect sign. In the control group, none of the 92 patients showed the transient gastric perfusion defect sign. In the cirrhotic group, the frequency of the transient gastric perfusion defect sign was significantly higher in the patients with PHG (75%, 36/48) than in patients without PHG (11.4%, 4/35). The sensitivity, specificity, positive predictive values, and negative predictive values of the sign for CT diagnosis of PHG in the cirrhosis group were 75, 88.6, 90, and 72.1% respectively.

CONCLUSION

The transient gastric perfusion defect sign could be used as a relatively specific sign of PHG in patients with cirrhosis.

259 DNA HYPOMETHYLATION OF FETAL FIBROBLASTS IMPROVES DEVELOPMENTAL COMPETENCY AND GENE EXPRESSION PATTERN IN PORCINE EMBRYOS FOLLOWING NUCLEAR TRANSFER

The inhibition of methyl groups in the DNA of donor cells has been hypothesized to improve the potential reprogramming by the enucleated ooplasm after nuclear transfer (NT). Previously, we reported that treatment of porcine fetal fibroblasts (PFF) with an inhibitor of methylation, 5-azacytidine (5-azaC) at 0.5 �m, results in the retention of desirable characteristics with a relative reduction in methylation, making cells more conducive for reprogramming (Mohana Kumar et al. 2006 Cell Tissue Res. 325, 445-454). To understand these observations further, the present study investigated the developmental competence and expression pattern of gene transcripts in porcine NT embryos from PFF (control) and 0.5 �m 5-azaC-treated PFF (PFF + 5-azaC) at 4-cell, 8-cell, morula, and blastocyst stages, and compared these with those of IVF and in vivo embryos. Cleavage rate was significantly (P &lt; 0.05) higher in IVF than in NT embryos from PFF and PFF + 5-azaC (86.7 � 5.2% vs. 65.8 � 5.3% and 69.3 � 4.4%, respectively). Similarly, significantly (P &lt; 0.05) higher blastocyst rates were observed in IVF embryos (27.2 � 2.1%). However, NT embryos from PFF + 5-azaC showed enhanced developmental potential with significantly (P &lt; 0.05) higher rates of blastocysts (21.3 � 2.2%) than NT embryos from PFF (14.8 � 1.9%). NT embryos from PFF + 5-azaC (33.8 � 4.1) had significantly (P &lt; 0.05) higher total cell numbers than from PFF (24.6 � 3.5), but did not differ in the proportion of apoptotic cells (6.9 � 1.8% and 7.2 � 2.1%, respectively). However, the high total cell number and lower incidence of apoptosis were observed in IVF and in vivo embryos (45.3 � 3.8, 2.7 � 0.8%, and 53.9 � 3.5, 1.2 � 0.9%, respectively). Alterations in the expression pattern of genes implicated in transcription and pluripotency (Oct4 and Stat3), DNA methylation (DNA methyltransferases: Dnmt1, Dnmt2, Dnmt3a, and Dnmt3b), histone acetylation (histone acetyltransferase 1-HAT1), and histone deacetylation (histone deacetylases-Hdac1, Hdac2, and Hdac3) were observed in NT embryos from PFF and PFF + 5-azaC compared with that in IVF and in vivo counterparts. However, the expression of genes in PFF + 5-azaC-NT embryos closely followed those of in vivo-derived embryos compared with PFF-NT embryos, and, interestingly, there was lower variability in the expression of genes related to DNA methylation. Our findings demonstrate that remodeling of the epigenetic status by partial reduction of somatic DNA methylation from donor cells is beneficial in improving the developmental competency of porcine NT embryos. Further, hypomethylated donors may be more efficiently reprogrammed to re-activate the expression of early embryonic genes. This work was supported by Grant No. R05-2004-000-10702-0 from KOSEF, Republic of Korea.

282 GENE EXPRESSION PATTERNS AND QUALITY OF BOVINE EMBRYOS PRODUCED UNDER DIFFERENT OXYGEN CONCENTRATIONS

Various factors are known to influence the survival and development of in vitro-produced embryos, including co-culture with somatic cells, antioxidants, and O2 tension. Studies in several species report that embryo development and quality were enhanced at low O2 concentrations. This study compared the effects of 2 O2 concentrations on IVP embryo development, embryo quality, and gene expression to those of in vivo counterparts. Cumulus–oocyte complexes were matured in vitro in TCM-199 with hormones and 10% FCS, and inseminated in TALP medium. Presumptive zygotes were cultured in SOF medium under either 5% or 20% O2 in air. In triplicate, sets of 5 embryos at the 2-cell, 4-cell, 8-cell, 16-cell, morula, and Day 7 blastocyst stages were used for analyzing the expression patterns of apoptotic (Bax and Bcl2), metabolism (Glut-1 and Glut-5), stress (Sox, Hsp70, and G6PDH), compaction (Cx43), oxidation (PRDX5, NADH, and MnSOD), and implantation (VEGF and IFN-tau) genes using real-time quantitative PCR. The expression of each gene was normalized to that of glyceraldehyde 3-phosphate dehydrogenase (GAPDH). Statistical analysis was performed with Bonferroni and Duncan tests by ANOVA (P &lt; 0.05). Cleavage rates did not differ among groups. Blastocyst and hatched blastocyst development in 5% O2 was significantly (P &lt; 0.05) higher than in 20% O2. Total cell number of in vivo blastocysts was significantly (P &lt; 0.05) higher than that of IVP blastocysts. ICM ratio and apoptosis of in vivo blastocysts were significantly (P &lt; 0.05) lower than for IVP blastocysts. The relative abundances (RAs) of Glut-1, Glut-5, MnSOD, NADH, PRDX5, Cx43, Bcl2, and IFN-τ were significantly (P &lt; 0.05) higher in in vivo embryos, whereas the RAs of Sox, G6PDH, Hsp70, Bax, and VEGF were significantly (P &lt; 0.05) lower than for IVP counterparts. In conclusion, culture at 5% O2 concentration resulted in higher rates of development to the blastocyst stage, higher total cell numbers, and decreased apoptosis. Furthermore, differences in expression of genes including Glut-1, Glut-5, Sox, G6PDH, Hsp70, Bax, Bcl2, Cx43, PRDX5, NADH, MnSOD, VEGF, and IFN-τ may prove useful in determining optimal culture conditions. This work was supported by ARPC (204119-03-SB010), Republic of Korea.

Cloning, sequence analysis, and characterization of the astA gene encoding an arylsulfate sulfotransferase from Citrobacter freundii

Arylsulfate sulfotransferase (ASST) transfers a sulfate group from a phenolic sulfate ester to a phenolic acceptor substrate. In the present study, the gene encoding ASST was cloned from a genomic library copy of Citrobacter freundii, subcloned into the vector pGEM3Zf(-) and sequenced. Sequencing revealed two contiguous open reading frames (ORF1 and ORF2) on the same strand and based on amino acid sequence homology, they were designated as astA and dsbA, respectively. The amino acid sequence of astA deduced from C. freundii was highly similar to that of the Salmonella typhimurium, Enterobacter amnigenus, Klebsiella, Pseudomonas putida, and Campylobacter jejuni, encoded by the astA genes. However, the ASST activity assay revealed different acceptor specificities. Using p-nitrophenyl sulfate (PNS) as a donor substrate, alpha-naphthol was found to be the best acceptor substrate, followed by phenol, resorcinol, p-acetaminophen, tyramine and tyrosine.

Poly(ethylene glycol)-block-poly(L-lysine) dendrimer: novel linear polymer/dendrimer block copolymer forming a spherical water-soluble polyionic complex with DNA

Methoxypoly(ethylene glycol)-block-poly(L-lysine) dendrimer was designed to form a water-soluble complex with plasmid DNA. The copolymer was synthesized by the liquid-phase peptide synthesis method. It was characterized by 1H NMR and matrix-assisted laser desorption ionization-time-of-flight (MALDI-TOF) mass spectrum. Agarose gel electrophoresis and DNase I protection assay proved that this linear polymer/dendrimer block copolymer assembled spontaneously with plasmid DNA, forming a water-soluble complex which increased the stability of the complexed DNA. Atomic force microscopy of the complex was evaluated at various charge ratios showing that the copolymer/DNA complex was like a globular shape.

Conservation of the segment 4 gene sequence and of a leucine zipper motif in VP4 among five US bluetongue viruses

Full-length cDNA copies of the segment 4 (M1) genes of US Bluetongue viruses serotype-2, -10, -11, -13, and -17 were selectively amplified using genomic double-stranded RNA segments from purified BTV virions as templates and a modified polymerase chain reaction (Clamp-R). They were then cloned into pUC19 plasmids and both strands of several clones were sequenced. The length of all five segment 4 genes is 1981 nucleotides, which is 30 nucleotides shorter than that of the BTV serotype-10 reported by Y. Yu, A. Fukusho, and P. Roy (Nucleic Acids Res. 15, 7206 (1987)). The 5'- and 3'-noncoding regions of all five segment 4 genes are identical among all serotypes. The plus sense strand of the BTV segment 4 gene, which encodes the VP4 protein, possesses a single long open reading frame with an initiation codon (ATG) at nucleotides 9-11 and a stop codon (TAA) at nucleotides 1941-1943. This open reading frame encodes for a protein of 644 amino acid residues with a predicted molecular weight of about 75 kDa and a pI of +7 to +7.9. A potential leucine zipper motif was detected near the carboxyl terminus of the deduced VP4 amino acid sequence. The phylogenetic analysis using the sequences of these five cognate segment 4 genes is consistent with the results of our previous phylogenetic studies of cognate genome segments 5, 6, 8, 9, and 10. Serotype-10, -11, -13, and -17 are closely related and serotype-2 is the most distantly related among the five US BTV serotypes.