Selection and use of reference genes in mouse mammary glands

Obtaining quantitative data concerning gene expression is important for understanding milk synthesis in mammary glands. Quantitative real-time PCR (qRT-PCR) is an efficient tool to calculate gene expression; however, it is necessary to find valid reference genes for normalization of qRT-PCR data. We applied the geNorm software to eight commonly used reference genes to identify the most stable and optimal genes for the mouse mammary gland. Based on this analysis, HPRT, RPL and GAPDH are the most appropriate reference genes for data normalization. We tested the expression of the alpha-lactalbumin and fatty acid synthase genes using these three reference genes, both normalized and non-normalized. The normalized mRNA expression ratio was significantly different from the non-normalized ratio. We recommend the use of these three reference genes for the normalization of qRT-PCR data in gene expression studies of mouse mammary glands.

Non-invasive foetal RHD genotyping via real-time PCR of foetal DNA from Chinese RhD-negative maternal plasma

BACKGROUND

A majority of studies predicting the foetal RhD blood group in free foetal DNA from RhD-negative maternal plasma have been conducted in Caucasian populations, whereas limited data have been accumulated for Asian populations. In this study, we assessed the feasibility of prenatal genotyping of RHD in RhD-negative Chinese pregnant women.

MATERIALS AND METHODS

Cell-free plasma DNA was extracted from 78 RhD-negative Chinese women carrying a singleton foetus (gestation between 14 and 40 weeks). Foetal DNA was confirmed by testing SRY or nine different polymorphic STR loci in the maternal plasma and buffy coat. Foetal RHD exons 5, 7 and 10 and intron 4 were successfully amplified with RQ-PCR. The RHD1227A allele was examined in all RhD-positive individuals. The foetal RHD genotyping results were compared with the infant cord blood serological analysis.

RESULTS

Among the 78 specimens, RHD genotyping results of 70 cases were in complete concordance with serological results from foetal umbilical cord blood. Sixty of these cases were identified as RhD-positive, and 10 cases were typed as RhD-negative. In addition, five cases were 'false-positives', while three cases were considered inconclusive. The detection rate was 89.7% (70/78). In four of the five 'false-positive' cases, the RhDel phenotype was assessed by detecting the RHD1227A allele. Thus, this method yielded a 94.9% (74/78) accuracy rate.

CONCLUSIONS

The correct foetal RhD phenotype may be accurately predicted from RhD-negative maternal plasma in Chinese subjects. The RHD1227A allele proved to be an important genetic marker in the RhDel Chinese population.

Human Hendra virus infection causes acute and relapsing encephalitis

AIM

To study the pathology of two cases of human Hendra virus infection, one with no clinical encephalitis and one with relapsing encephalitis.

METHODS

Autopsy tissues were investigated by light microscopy, immunohistochemistry and in situ hybridization.

RESULTS

In the patient with acute pulmonary syndrome but not clinical acute encephalitis, vasculitis was found in the brain, lung, heart and kidney. Occasionally, viral antigens were demonstrated in vascular walls but multinucleated endothelial syncytia were absent. In the lung, there was severe inflammation, necrosis and viral antigens in type II pneumocytes and macrophages. The rare kidney glomerulus showed inflammation and viral antigens in capillary walls and podocytes. Discrete necrotic/vacuolar plaques in the brain parenchyma were associated with antigens and viral RNA. Brain inflammation was mild although CD68(+) microglia/macrophages were significantly increased. Cytoplasmic viral inclusions and antigens and viral RNA in neurones and ependyma suggested viral replication. In the case of relapsing encephalitis, there was severe widespread meningoencephalitis characterized by neuronal loss, macrophages and other inflammatory cells, reactive blood vessels and perivascular cuffing. Antigens and viral RNA were mainly found in neurones. Vasculitis was absent in all the tissues examined.

CONCLUSIONS

The case of acute Hendra virus infection demonstrated evidence of systemic infection and acute encephalitis. The case of relapsing Hendra virus encephalitis showed no signs of extraneural infection but in the brain, extensive inflammation and infected neurones were observed. Hendra virus can cause acute and relapsing encephalitis and the findings suggest that the pathology and pathogenesis are similar to Nipah virus infection.

Alveolar macrophage inducible nitric oxide synthase-dependent pulmonary microvascular endothelial cell septic barrier dysfunction

Inducible nitric oxide (NO) synthase (iNOS) from neutrophils and alveolar macrophages (AM) contributes to the pathophysiology of murine septic acute lung injury (ALI). It is not known if AM iNOS has a direct effect on septic pulmonary microvascular endothelial cell (PMVEC) permeability. We hypothesized that AM iNOS mediates PMVEC permeability in vitro under septic conditions through NO and peroxynitrite. 100,000 confluent PMVEC on cell-culture inserts were co-incubated with iNOS+/+ vs. iNOS-/- AM, in various ratios of AM to PMVEC. PMVEC injury was assessed by trans-PMVEC Evans Blue-labelled albumin flux in the presence or absence of cytomix (equimolar TNF-alpha, IL-1beta and IFN-gamma). Cytomix stimulation dose-dependently increased trans-PMVEC EB-albumin flux, which was exaggerated (1.4+/-0.1% vs. 0.4+/-0.1% in unstimulated PMVEC, p<0.05) in the presence of iNOS+/+, but not iNOS-/-, AM in the upper compartment. Similarly, iNOS+/+, but not iNOS-/-, AM in the lower compartment also enhanced septic trans-PMVEC albumin leak. The mechanism of iNOS-dependent septic PMVEC permeability was pursued through pharmacologic studies with inhibitors of NOS, and scavengers of NO, superoxide, and peroxynitrite, and treatment of PMVEC with the NO donor, DETA-NONOate. Septic iNOS+/+ AM-dependent trans-PMVEC albumin leak was significantly attenuated by pharmacologic iNOS inhibition (L-NAME and 1400W), and scavenging of either NO (oxyhemoglobin), superoxide (PEG-SOD), or peroxynitrite (FeTPPS). Exogenous NO (DETA-NONOate) had no effect on PMVEC permeability. These data are consistent with a direct role of AM iNOS in septic PMVEC barrier dysfunction, which is likely mediated, in part, through peroxynitrite.

Viral morphogenesis and morphological changes in human neuronal cells following Tioman and Menangle virus infection

Tioman virus (TioPV) and Menangle virus (MenPV) are two antigenically and genetically related paramyxoviruses (genus: Rubulavirus, family: Paramyxoviridae) isolated from Peninsular Malaysia (2001) and Australia (1997), respectively. Both viruses are potential zoonotic agents. In the present study, the infectivity, growth kinetics, morphology and morphogenesis of these two paramyxoviruses in a human neuronal cell (SK-N-SH) line were investigated. Sub-confluent SK-N-SH cells were infected with TioPV and MenPV at similar multiplicity of infection. These cells were examined by conventional and immunoelectron microscopy, and virus titres in the supernatants were assayed. Syncytia were observed for both infections in SK-N-SH cells and were more pronounced during the early stages of TioPV infection. The TioPV titre increased consistently (10(1)) every 12 h after infection. In MenPV-infected cells, cellular material was frequently observed within budding virions, and microfilaments and microtubules were abundant. Viral budding was common, and extracellular MenPVs tended to be more pleomorphic compared to TioPVs, which appeared to be more spherical in appearance. The MenPV cytoplasmic viral inclusion appeared to be comparatively smaller, loose and interspersed with randomly scattered circle-like particles, whereas huge tubule-like cytoplasmic inclusions were observed in TioPV-infected cells. Both viruses also displayed different cellular pathology in the SK-N-SH cells. The intracellular ultrastructural characteristics of these two viruses in infected neuronal cells may allow them to be differentiated by electron microscopy.

Diagnostic value and complications of fine needle aspiration for primary liver cancer and its influence on the treatment outcome-a study based on 3011 patients in China

AIM

To determine the diagnostic value and major complications of fine-needle aspiration (FNA) for primary liver cancer (PLC) and its influence on the treatment outcome and prognosis.

METHODS

Information was gathered retrospectively for 3011 patients who presented with suspected PLC. Of which 2528 cases underwent ultrasound-guided fine-needle aspiration (US-FNA) biopsy. Patients were followed up through repeated office visits and imaging studies with a median follow-up of 7 months (range, 1-29 months).

RESULTS

The sensitivity, specificity, positive predictive value, negative predictive value and overall accuracy of cytological diagnosis by FNA biopsy for detection of liver malignancy were 91.5%, 100.0%, 100.00%, 59.1% and 92.4% respectively. All patients with AFP> or = 400 microg/L were associated with malignancy. Of 1154 patients with AFP<400 microg/L who were finally proved PLC, 945 were detected by FNA alone. Major complications included bleeding in 11 cases (5 of them died later), occurred mainly in hepatocellular carcinoma with superficial location, large tumors and severe cirrhosis, and implantation metastases in 5 cases, which were recognized as a subcutaneous nodule at the previous biopsy site. Implantation metastases were treated with resection or radiotherapy.

CONCLUSION

FNA biopsy is valuable for the diagnosis of PLC. However, complications of post-biopsy hemorrhage should not be ignored, as such bleeding may be fatal. Implantation seems to have little effect on the prognosis.

Effects of macrophage inducible nitric oxide synthase in murine septic lung injury

Inducible nitric oxide synthase (iNOS) contributes importantly to septic pulmonary protein leak in mice with septic acute lung injury (ALI). However, the role of alveolar macrophage (AM) iNOS in septic ALI is not known. Thus we assessed the specific effects of AM iNOS in murine septic ALI through selective AM depletion (via intratracheal instillation of clodronate liposomes) and subsequent AM reconstitution (via intratracheal instillation of donor iNOS+/+ or iNOS−/− AM). Sepsis was induced by cecal ligation and perforation, and ALI was assessed at 4 h: protein leak by the Evans blue (EB) dye method, neutrophil infiltration via myeloperoxidase (MPO) activity, and pulmonary iNOS mRNA expression via RT-PCR. In iNOS+/+ mice, AM depletion attenuated the sepsis-induced increases in pulmonary microvascular protein leak (0.3 ± 0.1 vs. 1.4 ± 0.1 μg EB·g lung−1·min−1; P < 0.05) and MPO activity (37 ± 4 vs. 67 ± 8 U/g lung; P < 0.05) compared with that shown in non-AM-depleted mice. In AM-depleted iNOS+/+ mice, septic pulmonary protein leak was restored by AM reconstitution with iNOS+/+ AM (0.9 ± 0.3 μg EB·g lung−1·min−1) but not with iNOS−/− donor AM. In iNOS−/− mice, sepsis did not induce pulmonary protein leak or iNOS mRNA expression, despite increased pulmonary MPO activity. However, AM depletion in iNOS−/− mice and subsequent reconstitution with iNOS+/+ donor AM resulted in significant sepsis-induced pulmonary protein leak and iNOS expression. Septic pulmonary MPO levels were similar in all AM-reconstituted groups. Thus septic pulmonary protein leak is absolutely dependent on the presence of functional AM and specifically on iNOS in AM. AM iNOS-dependent pulmonary protein leak was not mediated through changes in pulmonary neutrophil influx.

Demographic differences between consenters and non-consenters in an obstetric anesthesiology clinical study

Willingness to participate in obstetric anesthesiology clinical studies may be influenced by age, parity or ethnicity. This study was designed to determine whether there were demographic differences between consenters and non-consenters in a minimum local analgesic concentration clinical study. Four hundred and fifty-two women were approached for the study and the age, ethnicity and parity of patients who consented or declined to participate were collected. Ethnicity was categorized as Asian or Pacific Islander, black, Hispanic, white, or other. Parametric data were analyzed using t-tests and non-parametric data using chi(2) tests. There were no significant differences in the consent rate based on age or parity. Black Americans were more likely to consent than Asian Americans (P<0.001) and as likely to consent as white Americans. There were no statistically significant differences in the consent rate between Caucasian and Asian Americans. More studies are needed to determine the socioeconomic and demographic factors that affect consent rates of labor patients.

Effects of Anoectochilus formosanus Hayata extract and glucocorticoid on lung maturation in preterm rats

We investigated the effects of maternal administration of Anoectochilus formosanus extract and dexamethasone on lung maturation in preterm rats. A. formosanus group mothers were tube-fed A. formosanus extract (300 mg/kg body wt./day) for 7 days from days 12-18 of gestation. Dexamethasone group mothers were injected intraperitoneally with dexamethasone (0.2 mg/kg body wt.) in saline on day 18 of gestation. Control group mothers were similarly injected with saline alone. On day 19 of gestation, fetuses were delivered by cesarean section. A. formosanus treatment significantly increased the fetal lung/body weight ratio, as compared to dexamethasone treatment. Saturated phosphatidylcholine levels in fetal lung tissue and growth hormone levels in maternal serum were significantly increased in the A. formosanus- and dexamethasone-treated groups as compared to controls. The histological appearance of preterm rat lungs revealed extensive branching of intermediate airways, denser mesenchyme, and more epithelial tubules in the dexamethasone and A. formosanus groups as compared with the control group. These results suggest that antenatal A. formosanus treatment may play a role in accelerating fetal rat lung maturation.

Henipaviruses: recent observations on regulation of transcription and the nature of the cell receptor

Hendra virus (HENV) and Nipah virus (NIPV) are classified in the new genus Henipavirus, within the subfamily Paramyxovirinae, family Paramyxoviridae. The genetic and biological characteristics that differentiate henipaviruses from other members of the subfamily are summarized. Although they do not display neuraminidase and hemagglutination activities and in that regard resemble viruses in the genus Morbillivirus, several recent observations highlight similarities between henipaviruses and respiroviruses (genus Respirovirus) in structure and replication strategy. First, three-dimensional modeling studies suggest that the external globular head domain of the HENV G protein resembles that of respiroviruses rather than morbilliviruses. Second, the pattern of transcriptional attenuation in HENV-infected cells resembles that observed with Sendai virus, a respirovirus, and differs from that found in cells infected with measles virus, a morbillivirus. Henipaviruses have a broad host range in vitro and in vivo, indicating wide distribution of cellular receptor molecules. The extensive host range has been confirmed in a quantitative in vitro cell-fusion assay using recombinant vaccinia viruses expressing the attachment and fusion proteins of HENV and NIPV. Cell lines of diverse origin and which are permissive in the in vitro cell fusion assay have been identified and the pattern of relative susceptibilities is the same for both HENV and NIPV, implying that both viruses use the same cell receptor. Protease treatment of permissive cells destroys their ability to fuse with cells expressing viral envelope glycoproteins. Virus overlay protein binding assay (VOPBA) and radio-immune precipitation assays confirm that both HENV and NIPV bind to membrane proteins in the 35-50 kD range. Treatment of cell membrane proteins with N-glycosidase eliminates HeV binding activity in VOPBA whereas treatment with neuraminidase has no effect on binding. Thus preliminary evidence suggests that NIPV and HENV bind to the same glycoprotein receptor via a non-sialic acid-dependant mechanism.

Kinetics and hydrolysis mechanism of polymeric prodrugs containing ibuprofen, ketoprofen, and naproxen as pendent agents

Polymeric prodrugs were prepared using methacrylic acid (MA) copolymerization with 2-hydroxyethyl methacrylate (HEMA), covalently linked with ibuprofen (HI), ketoprofen (HK), or naproxen (HN). It was previously shown that the acceptable composition of drug-linked monomer in polymeric prodrugs to prevent gastric mucosa irritation and maintain water solubility was in the range of 20-40 mol%. To investigate the applicability of these polymeric prodrugs, hydrolysis rates of HK-25, HN-29, and HI-30 (the number indicates the mole percent of the drug-linked monomers in the polymeric prodrugs), were studied in vitro with or without esterase. The polymeric prodrugs released a major fraction of the parent drugs and a fraction of the hydroxyethyl ester drug derivatives (drug-EtOH). The calculated hydrolysis rate constants and results correlated to the drug structural solubility and steric hindrance are discussed. The anti-inflammatory properties of these polymeric prodrugs were evaluated using carrageenan-induced edema test. The results indicate that HK-25 and HN-29 display greater potency to inhibit acute inflammatory processes than the free drugs over long periods. HI-30, however, retains a potency comparable to that of free ibuprofen.

An estimation of the minimum number of SSR alleles needed to reveal genetic relationships in wheat varieties. I. Information from large-scale planted varieties and cornerstone breeding parents in Chinese wheat improvement and production

The genetic relationships of 43 wheat varieties were analyzed with SSR markers. The materials employed included 14 cornerstone breeding parents used before 1980 and another 29 other large-scale planted varieties currently in use in China. A total of 501 different alleles were amplified, including 166 alleles of the A genome, 174 of the B genome and 161 of the D genome. Data obtained were used to estimate genetic similarity using the DICE coefficient, and dendrograms were constructed using the UPGMA method. The dendrogram with 501 alleles successfully differentiated all the cornerstone breeding parents and the large-scale planted varieties, and the dendogram tree was basically consistent with the pedigrees of these varieties. The correlation coefficient between the genetic distance matrix of 501 alleles and that of 450 was 0.99. Correlation coefficients among random samples of alleles suggested that 350 to 400 alleles were needed to detect genetic relationships among common wheat varieties. Correlation coefficients of a genetic similarity matrix based on 580, and those of 501 and 400, random alleles were 0.96 and 0.94, respectively. However, there were marked differences between the matrix based on the 501 alleles and those based on markers located on the A-, B- or D-genome independently. The correlation coefficients between the genetic distance matrix of 501 alleles and alleles within A, B or D genomes were 0.77, 0.76 and 0.67. The estimation of genetic similarity should be based on data from all genomes rather than any one genome.

Photoelectron trapping in quadrupole and sextupole magnetic fields

A photoelectron-trapping phenomenon has been found in the simulation of the photoelectron cloud. It is found that the photoelectrons can be trapped in the quadrupole and sextupole magnetic fields for very long time until it longitudinally drifts out of the magnets, even a long bunch train separation is not sufficient to clear up the photoelectrons. Therefore, such a kind of long time trapped photoelectron cloud can cause coupled bunch instability. The trapping phenomenon is strongly beam dependent, especially on the bunch length. There is no such kind of trapping if the positron beam does not disturb the photoelectrons during the whole process. There is also no trapping for positron bunch with bunch length longer than the period of the photoelectron's gyration motion at the mirror points. The trapping is a mirror field trap which is caused by beam disturbance. The trapping phenomenon and mechanism will be presented in detail.

Synthesis and properties of a naproxen polymeric prodrug

A water-soluble polymeric prodrug containing a naproxen moiety was synthesized. The carboxylic groups of naproxen were condensed with the hydroxyl groups of 2-hydroxyethyl methacrylate (HEMA) to produce a drug-linked monomer, denoted HN. The polymeric prodrug was prepared by copolymerization of HN with methacrylic acid. The molar percentage of HN in the polymeric prodrug was 26 mol%, as determined by 1H NMR. To investigate the pertinence of this polymeric prodrug, the hydrolysis was studied in-vitro with or without esterase or lipase. The kinetics of enzymatic catalysis was calculated from a Lineweaver-Burk plot. The anti-inflammatory activity was evaluated using the carrageenan-induced oedema test. The polymeric prodrug released a major fraction of the free naproxen and a significant fraction of the hydroxyethyl ester derived-naproxen. The maximum hydrolysis rate Vmax, and the Michaelis constant Km were calculated to be 2.16 x 10(-5) equiv. mol L-1 min-1 and 5.11 x 10(-2) equiv. mol L-1. The maximum anti-inflammatory inhibition of free naproxen appeared at 2 h and quickly decreased thereafter. In contrast, the polymeric prodrug showed a maximum at around 2-3 h and then slowly decreased. This indicates that the polymeric prodrug displays greater potency than free naproxen in the inhibition of acute inflammatory processes over long periods.

Effect of dietary supplemental levels of vitamin A on the egg production and immune responses of heat-stressed laying hens

Two experiments were conducted to evaluate the effect of vitamin A supplementation of a commercial layer diet on the laying performance and immune function of heat-stressed hens. In Experiment 1, two different levels of vitamin A supplementation (3,000 and 9,000 IU/kg) were used to investigate the laying performance and antibody titer against Newcastle disease virus (NDV) of heat-stressed hens. Results showed that the high level of vitamin A supplementation (9,000 IU/kg) had a beneficial effect on the feed intake and laying rate of heat-stressed hens (P < 0.05), compared with the control group (3,000 IU/kg). The antibody titers were not influenced by the level of vitamin A (P > 0.05). In Experiment 2, the effect of four levels of vitamin A (3,000, 6,000, 9,000, and 12,000 IU/kg) on the antibody titer to NDV and T lymphocyte proportion was studied. The experimental birds were exposed to a high temperature (31.5 C) 15 d after NDV vaccination (Treatment 1) or immediately (Treatment 2). The results showed that the egg weight was increased (P < 0.01) by the high levels of vitamin A supplementation (6,000 and 9,000 IU/kg), but feed intake, laying rate, and body weight loss were not (P > 0.05). In Treatment 1, vitamin A had no significant effect on antibody titers against NDV in normal or hot environments but increased (P < 0.01) the proportion of alpha-naphthyl acetate esterase (ANAE)-positive cells. Vitamin A supplementation had a significant effect on NDV antibody titer and ANAE-positive cell proportion in Treatment 2 (P < 0.01). The results of the present study suggested that vitamin A supplementation in commercial layer diets to layer chickens under heat stress was beneficial to laying performance and immune function.

Functional expression and membrane fusion tropism of the envelope glycoproteins of Hendra virus

Hendra virus (HeV) is an emerging paramyxovirus first isolated from cases of severe respiratory disease that fatally affected both horses and humans. Understanding the mechanisms of host cell infection and cross-species transmission is an important step in addressing the risk posed by such emerging pathogens. We have initiated studies to characterize the biological properties of the HeV envelope glycoproteins. Recombinant vaccinia viruses encoding the HeV F and G open reading frames were generated and glycoprotein expression was verified by metabolic labeling and detection using specific antisera. Glycoprotein function and cellular tropism were examined with a quantitative assay for HeV-mediated membrane fusion. Fusion specificity was verified through specific inhibition by anti-HeV antiserum and a peptide corresponding to one of the alpha-helical heptad repeats of F. HeV requires both F and G to mediate fusion. Permissive target cells have been identified, including cell lines derived from cat, bat, horse, human, monkey, mouse, and rabbit. Fusion negative cell types have also been identified. Protease treatments of the target cells abolished fusion activity, suggesting that the virus is employing a cell-surface protein as its receptor.

[Experimental pharmacodynamic study on the anti-convulsion effect of shenpu decoction]

OBJECTIVE

To observe the anti-convulsion effect of Shenpu Decoction (SPD).

METHODS

Experiments were conducted in three acute convulsion models (cardiazol seizure, strychnine convulsion and maximal electrical shock). Models were divided into the control group (A, treated by normal saline), the high, middle and low dose SPD groups (B, C and D, treated with SPD 9 g/kg, 6 g/kg and 4 g/kg respectively), and the nitrazepam treated group (E). The anti-convulsion effect of SPD was evaluated by 50% convulsion dose (CD50) detected in each group.

RESULTS

In cardiazol convulsion model, the CD50 detected in group A-E were 63.3 +/- 3.4 mg/kg, 116.2 +/- 3.4 mg/kg, 105.6 +/- 3.7 mg/kg, 74.0 +/- 3.7 mg/kg and 197.2 +/- 3.3 mg/kg respectively, while they were 0.71 +/- 0.04 mg/kg, 1.21 +/- 0.04 mg/kg, 1.19 +/- 0.04 mg/kg, 0.94 +/- 0.04 mg/kg and 1.16 +/- 0.04 mg/kg respectively in the strychnine convulsion model, and 67.1 +/- 2.6 V, > 140 V, 109.4 +/- 3.5 V, 84.4 +/- 3.1 V and 128.4 +/- 3.9 V in the maximal electrical shock model respectively.

CONCLUSION

SPD has a good anticonvulsion effect.

Experimental infections of pigs with Japanese encephalitis virus and closely related Australian flaviviruses

The flavivirus Japanese encephalitis (JE) virus has recently emerged in the Australasian region. To investigate the involvement of infections with related enzootic flaviviruses, namely Murray Valley encephalitis (MVE) virus and Kunjin (KUN) virus, on immunity of pigs to JE virus and to provide a basis for interpretation of serologic data, experimental infections were conducted with combinations of these viruses. Antibody responses to primary and secondary infections were evaluated using panels of monoclonal antibody-based blocking enzyme-linked immunosorbent assays and microtiter serum neutralization tests (mSNTs). Identification of the primary infecting virus was possible only using the mSNTs. Following challenge, unequivocal diagnosis was impossible due to variation in immune responses between animals and broadened and/or anamnestic responses. Viremia for JE virus was readily detected in pigs following primary infection, but was not detected following prior exposure to MVE or KUN viruses. Boosted levels of existing cross-neutralizing antibodies to JE virus suggested a role for this response in suppressing JE viremia.

[Determination of the binding site of testis-specific nucleoporin BS-63 to transportin (karopherin beta 2) and the proof of their combination in vitro]

OBJECTIVE

To locate the binding site of testis-specific nucleoporin BS-63 to transportin (karopherin beta 2) and confirm their combination in vitro.

METHODS

Constructed different fragments of C terminal BS-63 was employed to localize the binding site of the testis-specific nucleoporin BS-63 to transportin by yeast two-hybrid system technique pull-down test was used to identify the interaction between the purified expressed fragments of BS-63 0.6 K and transportin in vitro.

RESULTS

BS-63 binding site to transportin was shortened from 1.6 kb to 0.6 kb which included a Ran binding domain (RanBD). SDS-PAGE and Western blot tests confirmed the recombinant purified protein coded by 0.6 kb fragment of BS-63 cDNA could interact with transportin in vitro.

CONCLUSIONS

In germ cells, the function of the testis-specific nucleoporin BS-63 localized at cytoplasmic side of NPC importing cargoes into nuclear may be accomplished by transportin cooperation.

Changes in hepatitis C virus population in serum and peripheral blood mononuclear cells in chronically infected patients receiving liver graft from infected donors

BACKGROUND

We have previously studied hepatitis C (HCV)-infected recipients of livers from HCV-infected donors and found that either the donor's strain or the recipient's strain predominate in serum. The current study was undertaken to determine whether these changes are complete and whether they are reflected in the population of virus associated with peripheral blood mononuclear cells (PBMCs).

METHODS

We analyzed HCV ribonucleic acid from sequential serum and PBMC samples from 11 and 8 patients, respectively. The relatively stable NS5 region was chosen for analysis because it allowed for dependable identification of donor and recipient strains. Viral sequences were analyzed by direct sequencing and by sensitive strain-specific polymerase chain reaction assays. These assays were capable of detecting the minor sequence present at a concentration 1:104-10-7 below that of the major sequence.

RESULTS

Five patients retained their original infecting strain; the donor strain was detected only transiently. In the remaining six patients, recipient strain was detected for the first few weeks, after which only the donor strain was consistently present. However, in one patient the second nondominant strain was detected from the background of the major strain on a single occasion 8 months after transplantation. All changes in serum were closely paralleled by those occurring in PBMCs.

CONCLUSIONS

Viral population changes in the setting of liver transplantation from HCV-infected donors to HCV-infected recipients occur simultaneously in PBMCs and serum. The takeover of one strain by another in PBMC- and serum-derived viral populations seemed to be complete and long lasting.

Extracellular domain of YWK-II, a human sperm transmembrane protein, interacts with rat Mullerian-inhibiting substance

The YWK-II protein in human spermatozoa is structurally related to the betaA4-amyloid precursor protein of Alzheimer disease and has high similarity with amyloid precusor homologues. Antibodies to the YWK-II protein agglutinate human spermatozoa and may be a potential cause of infertility. In the present study, a yeast two-hybrid system (MATCHMAKER Two-Hybrid System 2; Clontech, Palo Alto, CA) was used to screen a rat ovary cDNA library for potential ligands capable of interacting with the YWK-II component. Mullerian-inhibiting substance was found to interact with the extracellular domain of YWK-II protein. The interaction was confirmed by a binding experiment in vitro and surface plasmon resonance assays. The recombinant Mullerian-inhibiting substance can significantly increase the viability and longevity of human spermatozoa after 5 and 22 h of incubation, presumably through binding the YWK-II component on the sperm membrane. The results of this study indicate that the YWK-II sperm membrane protein may function as a receptor for Mullerian-inhibiting substance.

Relative contribution of hemopoietic and pulmonary parenchymal cells to lung inducible nitric oxide synthase (inos) activity in murine endotoxemia

Acute lung injury is an important feature of sepsis and increased iNOS expression and NO production contribute to the pathogenesis of this syndrome. We generated bone marrow-transplanted chimeric mice with iNOS expression limited to either inflammatory or pulmonary parenchymal cells, and assessed pulmonary iNOS activity and systemic levels of NO metabolites in an endotoxemic model of sepsis. We found that while both pulmonary parenchymal cells and inflammatory cells contribute to the increased lung iNOS activity in endotoxemia, pulmonary parenchymal cells contribute to a significantly greater degree. Using measurement of plasma NO(-)(x), whole body NO production was assessed in this model. We found that the main source of NO(-)(x) was again, parenchymal cells and not inflammatory cells. This is the first study to demonstrate that most of the increased NO production in this model of endotoxemic sepsis derives from parenchymal cells rather than inflammatory cells.

Molecular characterization of Menangle virus, a novel paramyxovirus which infects pigs, fruit bats, and humans

Menangle virus (MenV), isolated in August 1997 following an outbreak of reproductive disease in a piggery in New South Wales, is the second previously unclassified member of the family Paramyxoviridae to be identified in Australia since 1994. Similar to Hendra virus (HeV), MenV appears to be a virus of fruit bats (flying foxes) in the genus Pteropus. No serological cross-reactivity was detected between MenV and other known paramyxoviruses and to facilitate virus classification a cDNA subtraction method was used to obtain viral-specific cDNA from MenV-infected cells. Cloning and sequencing of the products enabled the entire sequences of the NP, P/V, M, F, and HN genes to be determined. Comparison of the nucleotide and deduced amino acid sequences for each gene with members of the family Paramyxoviridae, determination of the P gene mRNA editing strategy, and phylogenetic analyses confirmed that MenV is a new member of the genus Rubulavirus. However the deduced protein sequence of MenV HN exhibited only limited sequence homology when compared with attachment proteins of other paramyxoviruses. Key differences within the amino acid residues considered important determinants of neuraminidase activity suggest MenV HN is unlikely to possess the same degree of neuraminidase activity characteristic of other rubulavirus and respirovirus HN proteins.

Tioman virus, a novel paramyxovirus isolated from fruit bats in Malaysia

A search for the natural host of Nipah virus has led to the isolation of a previously unknown member of the family Paramyxoviridae. Tioman virus (TiV) was isolated from the urine of fruit bats (Pteropus hypomelanus) found on the island of the same name off the eastern coast of peninsular Malaysia. An electron microscopic study of TiV-infected cells revealed spherical and pleomorphic-enveloped viral particles (100--500 nm in size) with a single fringe of embedded peplomers. Virus morphogenesis occurred at the plasma membrane of infected cells and morphological features of negative-stained ribonucleoprotein complexes were compatible with that of viruses in the family Paramyxoviridae. Serological studies revealed no cross-reactivity with antibodies against a number of known Paramyxoviridae members except for the newly described Menangle virus (MenV), isolated in Australia in 1997. Failure of PCR amplification using MenV-specific primers suggested that this new virus is related to but different from MenV. For molecular characterization of the virus, a cDNA subtraction strategy was employed to isolate virus-specific cDNA from virus-infected cells. Complete gene sequences for the nucleocapsid protein (N) and phosphoprotein (P/V) have been determined and recombinant N and V proteins produced in baculovirus. The recombinant N and V proteins reacted with porcine anti-MenV sera in Western blot, confirming the serological cross-reactivity observed during initial virus characterization. The lack of a C protein-coding region in the P/V gene, the creation of P mRNA by insertion of 2-G residues, and the results of phylogenetic analyses all indicated that TiV is a novel member of the genus Rubulavirus.

Exposure of hepatitis C virus (HCV) RNA-positive recipients to HCV RNA-positive blood donors results in rapid predominance of a single donor strain and exclusion and/or suppression of the recipient strain

We have analyzed three cases of hepatitis C virus (HCV)-infected recipients who received blood from HCV-infected donors. Two recipients were exposed to two different HCV RNA-positive donors, and one was exposed to a single donor. All parental genomes from the actual infecting units of blood and the recipients were defined, and their presence in the follow-up serum samples was determined using sensitive strain-specific assays. The strain from one of the donors was found to predominate in all recipients' serum samples collected throughout the follow-up period of 10 to 30 months. In two recipients exposed to two infected donors, the strain from the second donor was occasionally found at very low level. However, the original recipients' strains were not detected. Our observations show that HCV-infected individuals can be superinfected with different strains, and this event may lead to eradication or suppression of the original infecting strain. Furthermore, our findings demonstrate that simultaneous exposure to multiple HCV strains may result in concomitant infection by more than one strain, although a single strain could rapidly establish its dominance. The results of the present study suggest the existence of competition among infecting HCV strains which determines the ultimate outcome of multiple HCV exposure.

Exposure of hepatitis C virus-negative recipients to > or =2 infected blood donors

This study analyzed 4 cases of hepatitis C virus (HCV)-naive transfusion recipients who developed hepatitis after receiving blood from >1 HCV-infected donor. One recipient was exposed to 4 donors, 2 were exposed to 3 donors, and 1 was exposed to 2 donors. For 3 recipients, the strain from 1 of the donors predominated in all follow-up samples collected for 8-40 months. For 2 recipients, the strain from the second donor was occasionally detectable with sensitive strain-specific assays. For the fourth recipient, the initially dominant strain was later supplanted by a strain from the other donor. Simultaneous exposure to multiple HCV strains may result in concomitant infection by >1 strain, although a single strain rapidly establishes its dominance. These observations are compatible with the presence of competition among infecting HCV strains that results in the dominance of 1 strain and competitive exclusion or suppression of other strains.

Inhibitory effect and mechanism of acarbose combined with gymnemic acid on maltose absorption in rat intestine

AIM: To compare the combinative and individual effect of acarbose and gymnemic acid (GA) on maltose absorption and hydrolysis in small intestine to determine whether nutrient control in diabetic care can be improved by combination of them.

METHODS: The absorption and hydrolysis of maltose were studied by cyclic perfusion of intestinal loops in situ and motility of the intestine was recorded with the intestinal ring in vitro using Wistar rats.

RESULTS: The total inhibitory rate of maltose absorption was improved by the combination of GA (0.1 g/L-1.0 g/L) and acarbose (0.1 mmol/L-2.0 mmol/L) throughout their effective duration (P < 0.05, U test of Mann-Whitney), although the improvement only could be seen at a low dosage during the first hour. With the combination, inhibitory duration of acarbose on maltose absorption was prolonged to 3 h and the inhibitory effect onset of GA was fastened to 15 min. GA suppressed the intestinal mobility with a good correlation (r = 0.98) to the inhibitory effect of GA on maltose absorption and the inhibitory effect of 2 mmol/L (high dose) acarbose on maltose hydrolysis was dual modulated by 1 g/L GA in vivo indicating that the combined effects involved the functional alteration of intestinal barriers.

CONCLUSION: There are augmented effects of acarbose and GA, which involve pre-cellular and paracellular barriers. Diabetic care can be improved by employing the combination.

A single chain Fv antibody displayed on phage surface recognises conformational group-specific epitope of bluetongue virus

A single chain fragment variable (scFv) antibody gene was isolated from hybridoma cell line secreting monoclonal antibody (MAb) 20E9 that recognises bluetongue virus (BTV) VP7. DNA fragments encoding variable regions of heavy and light chains were amplified by RT-PCR and library of scFv was constructed in phage vector. Two scFv clones that were selected showed specific reactivity with conformational epitope VP7. The N-terminal 22 amino acid residues of 20E9 light chain were identical to that deduced from scFv DNA sequence. An in-frame TAG stop codon was found in the coding sequence and its potential role in regulating the expression and stability of scFv in phage is discussed.

Evidence for the binding of a human sperm component with diaphanous protein

The YWK-II component of human sperm membrane is related to the betaA4-amyloid precursor protein (APP) of Alzheimer's disease. A yeast 2-hybrid system was used to screen a mouse testis cDNA expression library for potential ligands capable of interacting with the extracellular domain of the YWK-II component. One of the bound proteins was identified as hDIA1, which has 96% identity with p140mDia. These proteins are members of the formin homology family and participate in cytokinesis and organization of the actin cytoskeleton. By interacting with these diaphanous proteins, the YWK-II component may be involved in germ cell differentiation and in the structural formation of the acrosome.

Synthesis, characterization, antioxidative and antitumor activities of solid quercetin rare earth(III) complexes

Eight rare earth metal(II) complexes with quercetin ML3 x 6H2O [L=quercetin (3-OH group deprotonated); M = La, Nd, Eu, Gd, Tb, Dy, Tm and Y] have been synthesized and characterized by elemental analysis, complexometric titration, thermal analysis, conductivity, IR, UV, 1HNMR and fluorescence spectra techniques as well as cyclic voltammetry. The quercetin:metal stoichiometry and the equilibrium stability constant for metal binding to quercetin have been determined. The antioxidative and antitumor activities of quercetin x 2H2O and the complexes were tested by both the MTT and SRB methods. The results show that the suppression ratio of the complexes against the tested tumour cells are superior to quercetin x 2H2O. The property of LaL3 x 6H2O reacting with calf thymus DNA was studied by fluorescence methods. The La-complex binding to DNA has been determined by fluorescence titration in 0.05 M Tris-HCl, 0.5 M NaCl buffer (pH 7.0). The results indicate that the interaction of the complex with DNA is very evident.

Emerging viral diseases of Southeast Asia and the Western Pacific

Over the past 6 years, a number of zoonotic and vectorborne viral diseases have emerged in Southeast Asia and the Western Pacific. Vectorborne disease agents discussed in this article include Japanese encephalitis, Barmah Forest, Ross River, and Chikungunya viruses. However, most emerging viruses have been zoonotic, with fruit bats, including flying fox species as the probable wildlife hosts, and these will be discussed as well. The first of these disease agents to emerge was Hendra virus, formerly called equine morbillivirus. This was followed by outbreaks caused by a rabies-related virus, Australian bat lyssavirus, and a virus associated with porcine stillbirths and malformations, Menangle virus. Nipah virus caused an outbreak of fatal pneumonia in pigs and encephalitis in humans in the Malay Peninsula. Most recently, Tioman virus has been isolated from flying foxes, but it has not yet been associated with animal or human disease. Of nonzoonotic viruses, the most important regionally have been enterovirus 71 and HIV.

High levels of interleukin-8, soluble CD4 and soluble CD8 in bullous pemphigoid blister fluid. The relationship between local cytokine production and lesional T-cell activities

BACKGROUND

Bullous pemphigoid (BP) is an inflammatory subepidermal blistering disease associated with autoantibodies that recognize hemidesmosomal proteins. In addition to autoantibodies, the cell-mediated immune reaction is considered to play an important part in blister formation. Objectives To investigate some T-cell activation markers and inflammatory cytokines in the blister fluid and sera of patients with BP.

METHODS

We measured soluble CD4 (sCD4) and soluble CD8 (sCD8), which have been, respectively, associated with CD4 and CD8 T-cell activation. Enzyme-linked immunosorbent assays were also used to quantify the production of the leucocyte chemoattractant interleukin (IL) -8 and of the cytokines IL-1alpha, IL-1beta, IL-6, IL-10 and tumour necrosis factor-alpha in the blister fluid and sera of 11 patients with BP.

RESULTS

The mean +/- SD level of sCD4 in patients' blisters (42.4 +/- 25.0 units mL-1) was significantly elevated (P < 0.005) compared with that in their sera (11.2 +/- 8.9) and that in the suction blisters of 10 healthy people (11.4 +/- 5.4; P < 0.005). Mean +/- SD IL-8 concentrations in BP blisters (4683.6 +/- 3878.1 pg mL-1) were much higher than those in their sera (17.1 +/- 18.9; P < 0.001), and were very significantly elevated (P < 0.005) in comparison with those in suction blisters of healthy persons (512 +/- 292). sCD4 levels in BP blisters were inversely related to IL-10 levels (P = 0. 03, r2 = 0.85), IL-8 levels were positively related to sCD8 levels (P = 0.01, r2 = 0.54), and IL-1beta levels were positively related to sCD8 concentrations (P < 0.005, r2 = 0.65).

CONCLUSIONS

The correlations suggest that there is a delicately orchestrated network of cytokines and cell-mediated immunity operating in BP blisters.

Human sperm membrane protein (hSMP-1): a developmental testis-specific component during germ cell differentiation

Serum was obtained from an infertile woman having antibodies with sperm agglutinating activity. The antibodies interacted with a human sperm membrane protein (hSMP-1) with an estimated Mr of 55 kD. The gene (HSD-1) coding hSMP-1 was isolated from a human testis cDNA expression library and assigned the accession number U12978. The cDNA was conjugated to a prokaryotic expression vector to construct the recombinant vector, pRSET-HSD-I, which was expressed in Escherichia coli. The recombinant hSMP-1 was isolated and used to immunize rabbits to raise polyclonal antibodies. Usingan immunocytochemical technique, hSMP-1 protein was immunolocalized in germ cells of human testis at all stages of spermatogenesis. mRNAs were prepared from 16 different human tissues and analyzed by Northern blot using HSD-1 as probe. A positive reaction was elicited only with testis mRNA. The present findings suggest that the expression of hSMP-1 gene is testis-specific and occurs during the early stages of germ cell differentiation. In a comparative study, the location of the hSMP-I protein in sperm and in germ cells of the seminiferous tubules of rats was determined. The target antigen was immunolocated on the head and tail of rat sperm and in late spermatids and spermatozoa of rat testis. These results suggest that, in the rat, the HSD-1 gene is expressed during spermiogenesis.

The exceptionally large genome of Hendra virus: support for creation of a new genus within the family Paramyxoviridae

An outbreak of acute respiratory disease in Hendra, a suburb of Brisbane, Australia, in September 1994 resulted in the deaths of 14 racing horses and a horse trainer. The causative agent was a new member of the family Paramyxoviridae. The virus was originally called Equine morbillivirus but was renamed Hendra virus (HeV) when molecular characterization highlighted differences between it and members of the genus Morbillivirus. Less than 5 years later, the closely related Nipah virus (NiV) emerged in Malaysia, spread rapidly through the pig population, and caused the deaths of over 100 people. We report the characterization of the HeV L gene and protein, the genome termini, and gene boundary sequences, thus completing the HeV genome sequence. In the highly conserved region of the L protein, the HeV sequence GDNE differs from the GDNQ found in almost all other nonsegmented negative-strand (NNS) RNA viruses. HeV has an absolutely conserved intergenic trinucleotide sequence, 3'-GAA-5', and highly conserved transcription initiation and termination sequences similar to those of respiroviruses and morbilliviruses. The large genome size (18,234 nucleotides), the unique complementary genome terminal sequences of HeV, and the limited homology with other members of the Paramyxoviridae suggest that HeV, together with NiV, should be classified in a new genus in this family. The large genome of HeV also fills a gap in the spectrum of genome sizes observed with NNS RNA virus genomes. As such, it provides a further piece in the puzzle of NNS RNA virus evolution.

Immune responses in rats following oral immunization with attenuated Salmonella typhimurium expressing human sperm antigen

The HSD-I gene codes a human sperm membrane protein (hSMP-1) and has been assigned the accession number U12978. The gene is located on human chromosome 9, region p12-p13. When the 1.7-kb cDNA of HSD-I was digested sequentially with EcoRI, BamHI, and HindIII, a 550-bp cDNA fragment was formed, which codes for the extracellular domain. This fragment was cloned into the asd+ vector pYA3149 to construct pYA3149R. The recombinant plasmid was used to transform an avirulent deltacva, deltacrp, deltaasd vaccine strain of Salmonella typhimurium chi4550. The hSMP-1 component was localized on the surface of the head of mature rat spermatozoa by an immunofluorescence technique using polyclonal anti-hSMP-1 antibodies. Since rat sperm contain hSMP-1, this rodent can be used to assay the immunogenicity of pYA3149R. Female Wistar rats were immunized by oral administration of the recombinant Salmonella. Anti-hSMP-1 antibodies in blood and vaginal washes of immunized animals were determined. Both body fluids contained significant amounts of the antibodies, showing that the recombinant Salmonella is an effective oral immunogen in rats.

Effects of heat processing and storage on flavanols and sensory qualities of green tea beverage

This research was conducted to understand the effects of heat processing and storage on flavanols and sensory qualities of green tea extract. Fresh tea leaves were processed into steamed and roasted green teas by commercial methods and then extracted with hot water (80 degrees C) at 1:160 ratio (tea leaves/water by weight). Green tea extracts were heat processed at 121 degrees C for 1 min and then stored at 50 degrees C to accelerate chemical reactions. Changes in flavanol composition and sensory qualities of green tea extracts during processing and storage were measured. Eight major flavanols (catechin, epicatechin, gallocatechin, epigallocatechin, epicatechin gallate, catechin gallate, epigallocatechin gallate, and gallocatechin gallate) were identified in the processed tea extract. Among them, epigallocatechin gallate and epigallocatechin appeared to play the key role in the changes of sensory qualities of processed green tea beverage. The steamed tea leaves produced a more desirable quality of processed green tea beverage than the roasted ones.

Niacin protects the isolated heart from ischemia-reperfusion injury

Nicotinic acid (niacin) has been shown to decrease myocyte injury. Because interventions that lower the cytosolic NADH/NAD(+) ratio improve glycolysis and limit infarct size, we hypothesized that 1) niacin, as a precursor of NAD(+), would lower the NADH/NAD(+) ratio, increase glycolysis, and limit ischemic injury and 2) these cardioprotective benefits of niacin would be limited in conditions that block lactate removal. Isolated rat hearts were perfused without (Ctl) or with 1 microM niacin (Nia) and subjected to 30 min of low-flow ischemia (10% of baseline flow, LF) and reperfusion. To examine the effects of limiting lactate efflux, experiments were performed with 1) Ctl and Nia groups subjected to zero-flow ischemia and 2) the Nia group treated with the lactate-H(+) cotransport inhibitor alpha-cyano-4-hydroxycinnamate under LF conditions. Measured variables included ATP, pH, cardiac function, tissue lactate-to-pyruvate ratio (reflecting NADH/NAD(+)), lactate efflux rate, and creatine kinase release. The lactate-to-pyruvate ratio was reduced by more than twofold in Nia-LF hearts during baseline and ischemic conditions (P < 0.001 and P < 0.01, respectively), with concurrent lower creatine kinase release than Ctl hearts (P < 0.05). Nia-LF hearts had significantly greater lactate release during ischemia (P < 0.05 vs. Ctl hearts) as well as higher functional recovery and a relative preservation of high-energy phosphates. Inhibiting lactate efflux with alpha-cyano-4-hydroxycinnamate and blocking lactate washout with zero flow negated some of the beneficial effects of niacin. During LF, niacin lowered the cytosolic redox state and increased lactate efflux, consistent with redox regulation of glycolysis. Niacin significantly improved functional and metabolic parameters under these conditions, providing additional rationale for use of niacin as a therapeutic agent in patients with ischemic heart disease.

The presence of cross-reactive antibodies to rabbit haemorrhagic disease virus in Australian wild rabbits prior to the escape of virus from quarantine

Sera collected from Australian wild rabbits prior to the escape of rabbit haemorrhagic disease virus (RHDV) from Wardang Island were examined for RHDV antibodies using purified recombinant capsid protein VP60 expressed from baculovirus. A VP60-based indirect ELISA showed that 196 of 392 wild rabbit sera reacted (OD(450) >0.15) with VP60. Twenty sera (OD(450) ranging from 0.15-2.47), randomly chosen from the 196 positive sera, recognized the 64 kDa VP60 in Western blot analysis, indicating that the reactivity detected in ELISA is indeed specific to the VP60 antigen. In a separate study, sera of 23 rabbits from an RHD-free area after the escape of RHDV were tested by ELISA and 21 of the 23 rabbits were found to be positive. When these rabbits were challenged with a lethal dose of RHDV, 11 out of the 23 rabbits survived. The presence of RHDV-protective antibodies in some of these rabbits suggested that they had been exposed to a pre-existing non-virulent rabbit calicivirus closely related to RHDV. These results highlight the need to study the prevalence of, and to characterize, this viral agent in order to effectively control rabbit populations in Australia and New Zealand.

Comparison of serum specific IgE antibodies to staphylococcal enterotoxins between atopic children with and without atopic dermatitis

BACKGROUND

The skin of patients with atopic dermatitis (AD) exhibits a striking susceptibility to colonization and infection by Staphylococcus aureus. The exotoxins secreted by S. aureus can act as superantigens and classic allergens, inducing the production of functionally relevant specific IgE antibodies. The aim of this study was to compare the levels and positive rates of serum staphylococcal enterotoxin A (SEA)- and staphylococcal enterotoxin B (SEB)-specific IgE between atopic children with and without AD.

METHODS

Sixty children with AD, 55 children with respiratory allergy without AD, and 24 nonatopic healthy children were studied. The levels and positive rates of serum SEA- and SEB-specific IgE were compared among three groups. The correlation between the levels or positive rates of serum SEA/SEB-specific IgE and the severity of AD or the presence of previous skin infections was studied.

RESULTS

The children with AD had significantly higher levels and positive rates of serum SEA- and SEB-specific IgE than the atopic children without AD (P < 0.001) and the nonatopic children (P < 0.001). There was no significant difference in the levels and positive rates of serum SEA- and SEB-specific IgE between the atopic children without AD and the nonatopic children. With or without adjustment for the potential confounding effect of total serum IgE levels, the levels and positive rates of serum SEA- and SEB-specific IgE were significantly correlated with severity of AD (P <0.005), but they were not significantly different between AD children with and without previous skin infections.

CONCLUSIONS

SEA and SEB may contribute to chronic inflammation and exacerbation of AD through the IgE-mediated immune response.

Virus-like particles of calicivirus as epitope carriers

The VP60 of rabbit haemorrhagic disease virus (RHDV), when expressed in baculovirus, self-assembles into virus-like particles (VLP) which are antigenically and immunogenically indistinguishable from native virions. When the N-terminal 30 amino acid residues of VP60 were deleted and substituted by a well characterized six residue epitope from bluetongue virus capsid protein VP7 (Btag), the fusion protein retained its ability to self-assemble into VLPs. However, the size of these particles was only 27 nm, compared to 40 nm of VLPs derived from native VP60. The antigenicity of both VP60 and the Btag was retained as evident from ELISA and Western blot analyses. When Btag was fused at the C-terminus of VP60 without deletion, the fusion proteins formed VLPs of 40 nm in size and also retained their antigenicity, but the Btag antigenicity appeared weak at this fusion site.

Synthesis, characterization, and antibacterial activity of novel Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) complexes with vitamin K3-thiosemicarbazone

Vitamin K3-thiosemicarbazone (C12H11N3NaO4S2 x 5H2O, abbreviated as VT), a new Schiff base derivative, has been synthesized. Its crystal structure, determined by X-ray diffraction, is triclinic, space group P1. We have also prepared five novel complexes of VT with transition metals: [M(VT)(2)2H2O] x nH2O, (n = 1 and 2 for M = Cu(II) and Zn(II), respectively) and [M'(HVT)2Cl2] x mH2O, (m = 4, 5, and 7 for M' = Co(II), Mn(II), and Ni(II), respectively). These compounds were characterized by IR and UV-Vis spectroscopy, molar conductivity, thermal analyses, complexometric titration, and elemental analysis. In all the complexes, the VT ligand coordinates through sulfur and oxygen atoms, and the geometry around metal atom is best described as octahedral. In vitro tests of antibacterial activity showed that VT and its complexes with Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) all had strong inhibitory actions against G(+) Staphylococcus aureus, G(+) Hay bacillus, and G(-) Escherichia coli.

Hepatitis C epitopes from phage-displayed cDNA libraries and improved diagnosis with a chimeric antigen

A novel method for cloning DNase I fragments into bacteriophage display vector fUSE2 was used to create libraries expressing hepatitis C virus (HCV) protein fragments on the phage surface. Selection by panning with a mixture of sera from five HCV-seropositive individuals enabled identification of antigenic determinants in NS3 (amino acids 1,383-1,415), NS4 (amino acids 1, 930-1,938), and NS5 (amino acids 2,088-2,104). The NS3 result is the most accurate location to date of a major conformational determinant that cannot be mimicked by short peptides. Any expressed sequence from the phage library can be excised with Bgl II and cloned directly into the Bgl II site of an appropriate plasmid for bacterial expression. This enables production of chimeric proteins containing multiple antigenic determinants, illustrated by co-expression of the NS4P (amino acids 1,930-1,938) epitope with an NS4N fragment (amino acids 1,644-1,812) containing at least three linear HCV epitopes. When used to screen 35 individual HCV-positive sera by enzyme-linked immunosorbent assay (ELISA), the chimeric antigen detected eight more positives than NS4N alone and gave increased immunoreactivity with others. This approach of identifying antigenic regions by phage display and then co-expressing them as chimeric proteins may be generally applicable to the production of improved diagnostic antigens and recombinant vaccines.

Uneven distribution of hepatitis C virus quasispecies in tissues from subjects with end-stage liver disease: confounding effect of viral adsorption and mounting evidence for the presence of low-level extrahepatic replication

We have found differences among the populations of hepatitis C virus sequences in serum, peripheral blood mononuclear cells (PBMCs), and various tissues in patients with chronic hepatitis C. These results are compatible with the existence of independent viral compartments in the infected host. Our results also suggest that PBMCs, and probably various tissues, can selectively adsorb viral subpopulations differing in the E2 region.

Fasting limits norepinephrine release with myocardial ischemia and reperfusion

INTRODUCTION

Fasting for 24 hours improves functional recovery and reduces injury due to global ischemia and reperfusion. Since fasting affects catecholamine kinetics, and norepinephrine (NE) release has been implicated as a mediator of dysrhythmias and injury with myocardial ischemia, we hypothesized that fasting would limit NE release following ischemia and reperfusion as a mechanism of its beneficial effects.

METHODS

Hearts were isolated and perfused from rats either fed normally or fasted for 24 hours. Following baseline perfusion, hearts were subjected to 20 minutes of ischemia followed by reperfusion. Hemodynamics (developed and end-diastolic pressure) and dysrhythmias were monitored, and creatine kinase release on reperfusion was measured as a marker of cellular injury. NE tissue content was assessed prior to ischemia and NE release was measured upon reperfusion with and without blockade of the uptake1 carrier using desipramine.

RESULTS

The release of NE was reduced by fasting (0.52+/-0.14 vs. 1.47+/-0.15 nmol/gdw, p<0.001) associated with a reduction in dysrhythmias, lower creatine kinase release, and lower end-diastolic pressure on reperfusion. However, fasting did not reduce NE tissue stores prior to ischemia. Desipramine also reduced NE release on reperfusion and limited the frequency of dysrhythmias, but did not alter ischemic injury.

CONCLUSIONS

Fasting limits NE release after ischemia and reperfusion, an effect not due to lower NE stores. Lower NE release, either by fasting or blockade of the uptake1, carrier, significantly reduces the frequency of dysrhythmias. However, the amount of NE release, per se, does not alter ischemic injury, suggesting that the infarct limiting effect of fasting is not mediated by lower NE release.