Detection of enteric viruses and bacterial indicators in German environmental waters

Summary. A German mining lake and the supplying surface waters, which are located downstream of a sewage plant, were examined regarding their microbiological and virological quality. Between October 2002 and September 2003, specific PCR methods were used to determine the occurrence of enteric viruses in 123 water specimens drawn at different sites downstream of the waste water treatment plant and in 9 samples from the sewage plant influent. Detection rates in sewage plant effluents and surface water samples depended on sampling sites and were: 29–76% for enterovirus (EntV), 24–42% (astrovirus, AstV), 15–53% (norovirus, NV), 3–24% (rotavirus, RoV), 5–20% (hepatitis A virus, HAV) and 20% (adenovirus, AdV). AstV genome load of selected samples was between 3.7×10³ to 1.2×10⁸ genome equivalents per liter (gen.equ./l), depending on sampling location; NV average genome load ranged from 1.8×10⁴ to 9.7×10⁵gen.equ./l. Cell culture methods showed that three out of 18 PCR positive samples contained infectious EntV. Even though microbiolical parameters such as Escherichia coli, enterococci and coliphages indicated acceptable microbiological water quality, the virological data of this study suggest the possibility that surface waters may be a source for enteric viral infections.     

Mother-Baby psychiatric units (MBUs): National data collection in France and in Belgium (1999–2000)

Summary The French version of the Marcé checklist was used to collect data for 176 joint admissions to 11 psychiatric mother-baby units in 1999 and 2000. Mean age of the babies at admission ranged from 4 to 16 weeks. Two units also admitted older children. Mothers admitted were diagnosed with schizophrenia or chronic delusional disorders (n=44), acute transitory psychosis Bouffée délirante (n=20), bipolar disorders (n=20), depressive illness (n=38), personality disorders or intellectual disability (n=39), and other disorders (n=15). The mean duration of hospitalisation was 11 weeks. Units that also offered day-care admission in the same or a near-by unit had shorter mean admissions. More than half the womens partners (or babies fathers) had mental health problems. Women with schizophrenia or chronic delusional disorders and personality disorders or intellectual disability remained hospitalised longer, improved less, and were more often separated from their babies, or discharged with supervision, than women admitted with other diagnoses.     

The relationship between HPV16 and expression of CD44v6, nm23H1 in esophageal squamous cell carcinoma

Summary. The esophageal squamous cell carcinoma (ESCC) has high incidence in Shaanxi Province of China. More and more researches indicated that human papillomavirus type 16 (HPV16) might play an important role in carcinogenesis of ESCC but the relationship between HPV16 and CD44v6, nm23H1 has not been elucidated. HPV16 was detected by amplifying HPV16 E6 gene through polymerase chain reaction (PCR) method and the expression of CD44v6, nm23H1 in 40 ESCCs and fifteen normal esophageal mucosa (NEM) from Shaanxi Province was examined by Streptavidin-Peroxidase (SP) method using monoclonal antibody specific to CD44v6 and nm23H1. The positive rates of HPV16 E6 gene, CD44v6 and nm23H1 were 60% (24/40), 65% (26/40) and 45% (18/40) respectively in ESCCs and 26.67% (4/15), 33.33% (5/15) and 86.67% (13/15) respectively in NEMs. There exited statistical difference for HPV16, CD44v6 and nm23H1 between NEMs and ESCCs respectively (p<0.05). The relationship between HPV16 and the expression of CD44v6 in ESCCs was statistical significance (P=0.021), but no significant correlation was found between HPV16 and the expression of nm23H1 (P=0.436) in ESCCs. The infection rate of HPV16 had no statistical difference in all pathological features we observed, but the expression rates of CD44v6 and nm23H1 had statistical correlation with invasion (p=0.001, 0.013) and lymph nodes metastasis (p=0.014, 0.002) respectively. In different histology grade of ESSCs, the relationship between HPV16 and CD44v6 was statistical significance in grade I (p=0.044) but was not in grade II (p=0.165) and grade III (p=0.658), however as to the expression of nm23H1 there exited no statistical significance in all histology grades of ESCC (p>0.05). The expression rates of CD44v6 and nm23H1 were statistically different between grade I and II (p=0.004, 0.016) respectively and between grade I and grade III (p=0.014, 0.020), but not statistically different between grade II and III (p=0.792, 0.943) respectively. Our data firstly suggested that there existed the statistical relationship between the infection of HPV16 and the expression of CD44v6 in ESCCs and that HPV16 may be involved in invasion and metastasis of ESCC.     

A temperature-dependent inhibitory activity of serum on the capacity of Saccharomyces cerevisiae-derived hepatitis B surface antigen to bind to monocytes

Summary. Hepatitis B surface antigen, when produced in yeast (rHBsAg), is capable of binding to cells that express the lipopolysaccharide coreceptor CD14. This interaction is enhanced by a serum protein, the lipopolysaccharide binding protein (LBP). Here we report that most of the rHBsAg particles that attached to monocytes at 0°C, were not endocytosed but were released back into the serum-containing binding buffer at 37°C. Additionally, serum-dependent binding at 37°C was weak when compared to the serum-dependent attachment at 0°C. Pre-incubation at 37°C of cells together with serum did not abolish binding of freshly added rHBsAg at 0°C. However, pre-incubation of rHBsAg with serum at 37°C reduced attachment to cells following incubation at 0°C. Soluble CD14 and LBP, two serum proteins which can act as phospholipid transfer molecules, were shown not to be responsible for the inhibitory effect. Pre-incubation at 37°C of rHBsAg in serum-free hepatoma cell line-conditioned media resulted in a pronounced reduction in subsequent binding to cells at 0°C. These observations suggest that the temperature-dependent inhibitory effect is caused by serum factors that are probably secreted by hepatocytes.     

Usefulness of low-priming-volume cardiopulmonary bypass circuits and dilutional ultrafiltration in neonatal open-heart surgery

In neonate open-heart surgery, cardiopulmonary bypass (CPB) with extreme hemodilution induces an increased capillary permeability and accumulation of extravascular fluid, resulting in organ dysfunction. We evaluated the effects of a reduced priming volume for CPB and dilutional ultrafiltration (DUF) during neonatal open-heart surgery. Nineteen consecutive neonates with complete transposition of the great arteries who underwent an arterial switch operation were retrospectively assigned into two groups: the high-priming-volume circuit group (group A, n = 9) and the low-priming-volume circuit group (group B, n = 10). Patients in group B underwent surgery with a miniaturized CPB circuit and using the DUF technique. The priming volume of group B was nearly two-thirds that of group A. The water balance value after CPB and surgery was significantly lower in group B (–126 ± 118ml, –116 ± 116ml) than in group A (88 ± 218ml, 83 ± 165ml). Systolic blood pressure just after CPB was higher in group B (67.9 ± 9.1mmHg) than in group A (55.4 ± 10.3mmHg). Postoperative ventilatory support was shorter in group B (45 ± 19h) than in group A (68 ± 27h). In neonatal cardiac surgery, low-priming-volume CPB circuits and DUF improve the water balance during surgery and may attenuate any inflammatory reaction, which would help preserve postoperative organ function.     

Actin filaments around endothelial fenestrae in rat hepatic sinusoidal endothelial cells

The presence of microfilaments in the vicinity of sinusoidal endothelial fenestrae (SEF) suggests that the cytoskeleton of liver sinusoidal endothelial cells (LSEC) plays an important role in the modulation of SEF. In this study, we investigated actin filaments around SEF in LSECs. Monolayers of LSEC culture were established by infusing a rat liver with collagenase for 30min and then culturing in RMPI medium for 24h. Cells were reacted with 0.1% Triton X for 5s and 15% glycerinated PHEM buffer (60mM PIPES, 25mM HEPES, 10mM EGTA, 2mM MgCl, pH 6.9) containing heavy meromyosin for 10min and observed under a transmission electron microscope. By electron microscopy with the modified heavy meromyosin decorated reaction, actin filaments were clearly demonstrated around SEF in LSEC.     

The complete nucleotide sequence of the genome RNA of Lily symptomless virus and its comparison with that of other carlaviruses

Summary. The complete genomic nucleotide sequence and genome structure of Lily symptomless virus (LSV), a lily-infecting carlavirus, have been obtained. The genome of the Korean strain of LSV, LSV-Kr, was 8,394 nucleotides long and contained six open reading frames (ORFs) coding for proteins of Mr 220kDa (1,948aa), 25kDa (228aa), 12kDa (106aa), 7kDa (64aa), 32kDa (291aa) and 16kDa (140aa) from the 5 to 3 end, respectively, which is typical of carlaviruses. Genetic heterogeneity was observed in the ORF1 gene. A total of 221 of 5,847 nucleotides (nt) were heterologous in the ORF1 of replicase; 162nt portions were silent and 59nt resulted in amino acid changes. This heterogeneity indicates that the LSV-infecting lily plants contained a genetically heterogeneous population of LSV (quasispecies). Overall similarities to those of other carlaviruses for the six ORFs of LSV were from 76.1% to 31.6% and from 87.3% to 13.7%, at nucleotide and amino acid levels, respectively. The ORF1 replicase gene of LSV shares 40.9% to 56.8% and 48.9% and 58.6% identities with that of 5 other carlaviruses at the amino acid and nucleotide levels, respectively. LSV was closest to Blueberry scorch virus (BlScV) in this ORF, among the carlaviruses for which sequence information is available. The three triple gene blocks (ORF2-4), ORF5 (coat protein) and 3-proximal 16kDa ORF6 genes were further analyzed, and phylogenetic trees for the coding regions indicate that the LSV was the most closely related to Kalanchoe latent virus and BlScV. This is the first report of the complete nucleotide sequence and genome structure of LSV.Received December 13, 2002; accepted May 14, 2003 Published online July 17, 2003     

Analysis of cytosolic and lysosomal pH in apoptotic cells by flow cytometry

Several reports indicate that the cytosol is acidified during apoptosis although the mechanism is not yet fully elucidated. The most acidic organelle found in the cell is the lysosome, raising the possibility that lysosomal proton release may contribute to the cytosolic acidification. We here describe methods for measurement of the cytosolic and lysosomal pH in U937 cells by a dual-emission ratiometric technique suitable for flow cytometry. Cytosolic pH was analysed in cells loaded with the fluorescent probe BCECF, while lysosomal pH was determined after endocytosis of FITC-dextran. Standard curves were obtained by incubating cells in buffers with different pH in the presence of the proton ionophore nigericin. Apoptosis was induced by exposure of cells to 10ng/ml TNF- for 4h, and apoptotic cells were identified using a fluorescent marker for active caspases. By gating of control and apoptotic cells, the cytosolic and lysosomal pH were calculated in each population. The cytosolic pH was found to decrease from 7.2 ± 0.1 to 5.8s±0.1 and the lysosomal increased from 4.3±0.4 to 5.2±0.3. These methods will be useful in future attempts to evaluate the involvement of lysosomes in the acidification of the cytosol during apoptosis.     

Z-line structural diversity in frog single muscle fiber in the passive state

The structural changes of the Z-line between small square net (ss) and basket weave (bw) cross-sectional patterns were examined using intact single fibers and mechanically skinned fibers in the passive state to determine if the pattern is related to the sarcomere length (SL) and if the pattern undergoes a reversible transition in low- and high-osmotic medium.Frog single fibers were isolated from the anterior tibial muscle in Ringer's solution. Entirely or partially skinned single fibers were prepared in relaxing solution (also called low-osmotic medium).The high osmotic medium contained 10% polyvinylpyrrolidone (PVP) in relaxing solution.The sarcomere length (SL) of each fiber was measured directly by use of a laser beam or indirectly from electron micrographs with use of a correction factor. The ss and bw forms in cross sections were quantified by analysis of electron micrographs. The results show that the structural change of Z-line occurs around bw 2.3–2.4m ss (n = 25) and bw 3.1–3.2m ss (n = 13) in intact single fibers and skinned fibers, respectively. With the quick freeze-freeze substitution method, an intact single fiber with a SL of 2.35m showed almost 100% of ss form. The structural transition in cross section was also confirmed in four partially skinned fibers, where patterns went from mostly ss form (intact portion) to mostly bw form (skinned portion) at the SL between 2.40 to 3.20m.The reversibility of the change between ss and bw was proved by using low- and high-osmotic medium. The transition and reversion of cross-sectional patterns both occur in the passive state.     

Molecular and cytogenetic organization of the 5S ribosomal DNA array in chicken (Gallus gallus)

The 5S ribosomal (r) RNA genes encode a small (120-bp) highly-conserved component of the large ribosomal subunit. The objective of the present research was to study the molecular and cytogenetic organization of the chicken 5S rDNA. A predominant 2.2-kb gene (5S) consisting of a coding and intergenic spacer (IGS) region was identified in ten research and commercial populations. A variant gene repeat of 0.6kb (5S) was observed in some of the populations. Genetic linkage analysis and cytogenetic localization by fluorescence in-situ hybridization assigned the 5S rDNA to chromosome 9. The 5S rDNA array was determined to be 80.2±7.0kb upon electrophoretic sizing following EcoRV digestion. Sequence analysis of 5S IGS regions revealed considerable conservation between chicken subspecies (98.4% identity) as well as homology with vertebrate Pol III promoter and regulatory sequence motifs. Minor intraindividual sequence variation within 1000bp of IGS was observed in four cloned Red Jungle Fowl (Gallus gallus gallus) 5S repeats (95.5% identity in this region). Sequence comparisons between IGS regions of 5S and 5S genes indicated two short continuous (>20bp) and many short non-continuous homologous regions as well as other conserved features such as promoter and termination motifs.     

Synthesis of Seoul virus RNA and structural proteins in cultured cells

Summary. Seoul virus is a hantavirus that causes hemorrhagic fever with renal syndrome (HFRS). The virion has a tripartite (S, M, and L) negative-stranded RNA genome, which is characteristic of the family Bunyaviridae. However, the molecular basis of virus replication is not well known. We established a Northern blot hybridization (NB) procedure using digoxygenin-labeled RNA probes, to quantitate the hantaviral plus- and minus-strand RNAs separately. Virus RNA replication was analyzed in infected Vero E6 cells. When the Vero E6 cells were infected with Seoul virus strain KI-83-262 (KI) at m.o.i.=0.25, the plus-strand RNA was detected within 1h post-infection (hpi), and the minus-strand RNA was detected subsequently. Using laser confocal microscopy, the nucleocapsid protein (NP) was detected within 2hpi, and accumulated as scattered granules in the cytoplasm until 24hpi. In contrast, the G2 protein first appeared at 8hpi, was immediately transported to the Golgi, and accumulated in the Golgi until 24hpi. Infectious virus particles were released into the medium at 24hhpi. These findings indicate that hantavirus RNA replication starts with the appearance of NP at 2hpi, glycoproteins then accumulate gradually in the Golgi, and virion formation is initiated once the viral RNAs and proteins have accumulated.Received October 10, 2002; accepted April 25, 2003 Published online July 17, 2003     

A virus related to <Emphasis Type="Italic">Soybean mosaic virus</Emphasis> from <Emphasis Type="Italic">Pinellia ternata</Emphasis> in China and its comparison with local soybean SMV isolates

Summary. A potyvirus isolated from Pinellia ternata in China was characterised and shown to be related to Soybean mosaic virus (SMV). The virus was pathogenic on P. ternata and some soybean cultivars, whereas the local soybean SMV isolate HH5 did not infect P. ternata. Western blot experiments demonstrated a serological relationship between the virus from Pinellia, SMV and Watermelon mosaic virus (WMV). The complete nucleotide sequences of the Pinellia virus (isolate P-1, 9735nt) and of the Chinese soybean SMV isolates HH5 (9585nt) and HZ (9588nt) were determined. A 1733nt sequence at the 3-terminus of a second isolate from Pinellia (isolate P-2) was also determined. The predicted polyprotein of isolate P-1 has 83% amino acid (aa) identity with those of published SMV sequences. In many parts of the genome, aa identity was about 90% but it was much lower in the P1 protein region (24–29%), where it more closely resembled Dasheen mosaic virus (62%). The partial sequence of isolate P-2 had 91%nt identity to P-1 and both isolates resembled a recent sequence in the public databases (AF469171) wrongly named Zantedeschia mosaic virus. The two complete SMV soybean sequences had 93–95%nt identity with those of the previously sequenced isolates and >97% amino acid identity. Phylogenetic analysis and comparisons of coat proteins suggest that the Pinellia, WMV and SMV potyviruses should probably be treated as strains of the same species.     

Molecular analysis of <Emphasis Type="Italic">Fiji disease virus</Emphasis> genome segments 5, 6, 8 and 10

Summary. The complete sequences of Fiji disease virus (FDV) genome segments 5 (S5), S6, S8 and S10 were obtained and comprised 3150nt, 2831nt, 1959nt and 1819nt, respectively. Each segment contained a single ORF which encoded putative proteins of 115kDa, 97kDa, 69kDa and 63.0kDa, respectively. The putative amino acid sequences encoded by S5 and S6 contained putative leucine zipper motifs while FDV S5 and S8 each contained an ATP-GTP-binding motif. At the amino acid level, FDV S5, S6, S8 and S10 showed most similarity to the corresponding segments of Rice black-streaked dwarf virus. Based on sequence similarities, it is predicted that FDV S8 encodes a minor core protein, while FDV S10 encodes an outer capsid protein. The evolutionary relationships of FDV to other reoviruses are discussed.The nucleotide sequence data for FDV S5, S6, S8 and S10 are available in the DDBJ/EMBL/GenBank databases under the accession numbers AY029521, AF356083, AY297693 and AY297694, respectively.     

Strains of coxsackie virus B4 differed in their ability to induce acute pancreatitis and the responses were negatively correlated to glucose tolerance

Summary. The outcome of infections with three CVB4 strains known to replicate in human pancreatic islet cells (E2, V89 4557 and VD2921) and one CVB3 strain (Nancy) in CBA/J mice with regard to viral replication, inflammation and glucose tolerance was studied. Isolation of virus from hearts, livers and pancreata was performed 7, 14 and 21 days post infection (pi). All strains could be equally well isolated from the pancreata and all but one strain, V89 4557, could be isolated from the hearts. The titers of neutralizing antibodies in the mice infected with the CVB4 strain V89 4557 were significantly lower than in mice infected with the other strains (p<0.01). Even though virus was isolated from both heart and pancreata, immunohistochemical staining only revealed inflammatory cells in the latter. Seven days pi there was a significant difference between the strains in this respect i.e. mice infected with CVB3 and the E2 strain revealed more CD4⁺ lymphocytes, macrophages and granulocytes compared to mice infected with the other CBV strains (p<0.05). Glucose tolerance tests performed at day 14 and at day 115 pi revealed normal kinetics of glucose absorption from the blood in the control mice and in mice infected with the strains that induced severe inflammation of the pancreas (E2 and CVB3). In contrast, the glucose clearance in mice infected with the CVB4 strains V89 4557 and VD2921 were significantly impaired compared to uninfected controls and compared to mice infected with the other CVB strains (p<0.01). Mice infected with CVB4 strains V89 4557 also had a significantly impaired clearance of glucose 120min after injection (p<0.05) even though no virus could be isolated and no inflammation was detected in the pancreata at that time point. These results show that there is a clear strain difference with regard to the ability to affect clearance of glucose from the blood as late as 115 days pi as well as the degree of inflammation in the pancreas. This indicates that the in vitro diabetogenic strains (VD2921 and V89 4557) also in vivo can induce a pre-diabetic state in CBA/J mice.     

Changes in level of virus accumulation and incidence of infection are critical in the characterization of <Emphasis Type="Italic">Rice tungro bacilliform virus</Emphasis> (RTBV) resistance in rice

Summary. Analysis by enzyme-linked immunosorbent assay showed that Rice tungro bacilliform virus (RTBV) accumulated in a cyclic pattern from early to late stages of infection in tungro-susceptible variety, Taichung Native 1 (TN1), and resistant variety, Balimau Putih, singly infected with RTBV or co-infected with RTBV+Rice tungro spherical virus (RTSV). These changes in virus accumulation resulted in differences in RTBV levels and incidence of infection. The virus levels were expressed relative to those of the susceptible variety and the incidence of infection was assessed at different weeks after inoculation. At a particular time point, RTBV levels in TN1 or Balimau Putih singly infected with RTBV were not significantly different from the virus level in plants co-infected with RTBV+RTSV. The relative RTBV levels in Balimau Putih either singly infected with RTBV or co-infected with RTBV+RTSV were significantly lower than those in TN1. The incidence of RTBV infection varied at different times in Balimau Putih but not in TN1, and to determine the actual infection, the number of plants that became infected at least once anytime during the 4wk observation period was considered. Considering the changes in RTBV accumulation, new parameters for analyzing RTBV resistance were established. Based on these parameters, Balimau Putih was characterized having resistance to virus accumulation although the actual incidence of infection was >75%.Received December 18, 2002; accepted March 19, 2003 Published online June 5, 2003     

Pattern of <Emphasis Type="Italic">N</Emphasis> gene-mediated systemic hypersensitive response and turnover of viral replicase protein in tobacco

Summary. We examined the pattern of the N gene-mediated systemic hypersensitive response (HR), which was induced by tobacco mosaic virus upon temperature shift, and analyzed the distribution of the coat protein and the virus-encoded 126kDa replicase protein (126K protein) by immunoblot analysis. In the middle- and lower-positioned leaves, HR occurred in the advancing edge of the infected area, where we detected both the coat protein and the 126K protein. In the areas between the main vein and the advancing edge of these leaves, we observed no HR and did not detect 126K protein, though virus was present in these areas. In the upper-positioned mosaic leaves, patterns of the HR were different depending on the leaf age. In these mosaic leaves, the mechanism preventing the virus from invading dark green tissue seemed to be broken down in 8–14 days old leaves, and HR was observed only in the tissue just invaded by the virus, where we detected the 126K protein. Those results suggested that the viral 126K protein was present when the viral replication was taking place, and easily degraded when the amount of the virus was saturated in the cells.     

Identification and Characterization of the UL24 Gene Product of Herpes Simplex Virus Type 2

The UL24 gene of herpes simplex virus type 2 (HSV-2) is predicted to encode a 281 amino acid protein with a molecular mass of 30.5kDa. In this study, the HSV-2 UL24 gene product has been identified by using a rabbit polyclonal antiserum produced against a recombinant protein containing the full-length UL24 gene product of HSV-2 fused to glutathione-S-transferase. The antiserum reacted specifically with a 32kDa protein in HSV-2 186-infected Vero cells and with 31 and 32kDa proteins in UL24-expressing Cos-7 cells. Accumulation of UL24 protein to detectable levels required viral DNA synthesis, indicating that the protein was regulated as a late gene. UL24 protein was found to be associated with purified HSV-2 virions and C capsids. Indirect immunofluorescence analysis demonstrated that the UL24-specific fluorescence was detected in perinuclear regions of the cytoplasm and/or in the nucleus as small discrete granules from 9h post infection (hpi). Furthermore, the UL24 protein expressed singly was detected predominantly in the nucleus and slightly in the cytoplasm at 24h after transfection, with branch-like cytoplasmic protruding structures. Strong nucleolus staining was visible in partial cells.     

<Emphasis Type="Italic">Rice stripe virus</Emphasis> 23.9 K protein aggregates and forms inclusion bodies in cultured insect cells and virus-infected plant cells

Summary. The genome of Rice stripe virus (RSV, genus Tenuivirus) contains seven open reading frames (ORFs). Little is known about the products of four of these ORFs, including the 23.9K protein encoded by the virus-sense ORF of RNA3. Western blotting revealed that the 23.9K protein was synthesized in the host plant and also in the planthopper vector of RSV. Using a baculovirus vector, the 23.9K protein was expressed, both unfused and fused with red-shifted green fluorescent protein, in Spodoptera frugiperda cells. Inclusion bodies were observed by light microscope in cells expressing fused or unfused proteins. Inclusion bodies in cells expressing the fused protein fluoresced under blue light. By immunoelectron microscopy, electron-dense inclusion bodies in cells expressing the unfused protein were specifically labeled with 23.9K protein antiserum. Moreover, electron-dense masses labeled with 23.9K protein antiserum were observed in virus-infected wheat tissue by electron microscopy. This paper thus demonstrates that RSV 23.9K protein can aggregate in vivo and form inclusion bodies in infected plant tissue.Received December 24, 2003; accepted June 11, 2003 Published online August 7, 2003     

Attenuated Lapinized Chinese Strain of Classical Swine Fever Virus: Complete Nucleotide Sequence and Character of 3′-Noncoding Region

The complete nucleotide sequence including precise 5- and 3-terminal non-coding regions (NCRs) of the attenuated lapinized Chinese strain (HCLV) of Classical Swine Fever Virus (CSFV) was determined from overlapping cDNA clones constructed by separated RT-PCR and rapid amplification of cDNA ends (RACE) methods. The genomic RNA of the HCLV strain consists of 12,310 nucleotides (nts) including 374nts and 242nts in the 5- and 3-NCRs, respectively. It contains one large open reading frame (ORF) encoding a polyprotein of 3,898 amino acids with a calculated molecular weight of 437.6kDa. There is one notable insertion of 12 continuous nts, CTTTTTTCTTTT in the 3-NCR of HCLV genomic cDNA when compared with its parental virulent Shimen strain. Sequence alignment of partial 3-NCR reveals two groups of CSFV vaccine strains carrying similar T-rich insertions at different positions in this region. Computer-predicted secondary structures suggest that T-rich insertion greatly change the structures and thus decrease the promoter functions of 3-NCRs during the replications of these two groups of CSFV vaccine strains.     

Comparison between closed-loop portal and peripheral venous insulin delivery systems for an artificial endocrine pancreas

To establish the ideal insulin delivery route for an artificial endocrine pancreas, we examined the effectiveness of closed-loop portal insulin delivery. We investigated the effects of the route of insulin delivery on net hepatic glucose balance (NHGB) in dogs under pancreatic clamp conditions with somatostatin plus basal glucagon and insulin infusions. A constant rate of suprabasal insulin was infused via the portal vein or a peripheral vein, and glucose was infused into the portal vein for 180min. The mean net hepatic glucose uptake (NHGU) values in the portal insulin infusion group (PI group) were significantly greater than those in the peripheral venous insulin infusion group (VI group); the changes from the baseline values at 180min were 3.54 ± 0.66 and 2.45 ± 0.82mgkg^–1min^–1 in the PI and VI groups, respectively, P < 0.05. Furthermore, dogs under pancreatic clamp conditions were controlled after a 2-g/kg oral glucose load by applying the closed-loop intraportal (PO) or intravenous (IV) insulin infusion algorithm. There were no significant differences in glycemic control and insulin requirements between these algorithms. However, the maximum peripheral venous and arterial plasma insulin concentrations with the PO algorithm were significantly lower than those with the IV algorithm [305.1 ± 68.9 and 468.1 ± 66.9pmol/l (peripheral vein) and 305.3 ± 62.9 and 469.6 ± 85.1pmol/l (artery) with the PO and IV algorithms, respectively, P < 0.05]. On the other hand, the maximum portal plasma insulin concentration with the PO algorithm was significantly higher than that with the IV algorithm (619.9 ± 101.7 and 414.3 ± 79.9pmol/l with the PO and IV algorithms, respectively, P < 0.05). The mean NHGU values with the PO algorithm were significantly greater than those with the IV algorithm. Our results confirmed that closed-loop portal insulin delivery is feasible with regard to both insulin profiles and hepatic glucose handling in vivo, and indicated that the portal vein is the most suitable insulin delivery route for the artificial endocrine pancreas.