Two G3 feline rotavirus strains lacking cross-neutralization reactions represent distinct subtypes of serotype G3

Two feline rotavirus strains, FRV-1 and FRV64, that have been shown to lack cross-neutralization reactions despite the sharing of serotype G3 were examined by plaque-reduction neutralization assays in relation to other G3 strains originating from cats, dogs, humans and monkeys. While FRV-1 and human G3 strains constituted one subtype (G3A), FRV64, canine strains and simian strains constituted another subtype (G3B).     

Isolation of a serotype G6P11 bovine rotavirus showing two-way cross-neutralization with the serotype G10P11 virus

Four stains designated as OB94-1 to OB94-4 of group A bovine rotavirus (BRV) were isolated from 35 fecal samples of calves with diarrhea in sporadic outbreaks. In VP7 (G) and VP4 (P) serotyping of these isolates, OB94-1 to OB94-3 were determined as G6P5, G6P5 and G10P5, respectively, by cross neutralization (NT) test and the G- and P- serotyping polymerase chain reaction (PCR) analysis. OB94-4 showed a one-way antigenic relation with the Lincoln stain (G6P1) and a weak antigenic relationship with the KK3 strain (G10P11), and was determined as G6P11 by the PCR method. Thus, OB94-4 was shown to be a new G6 BRV with different antigenic properties from the others in the NT test.     

Naturally occurring dual infection with human and bovine rotaviruses as suggested by the recovery of G1P8 and G1P5 rotaviruses from a single patient

Culture adaptation of rotaviruses from an infant with severe diarrhea in Cincinnati, Ohio, yielded not only a virus with the original RNA electropherotype (CJN) but also rotaviruses with other electropherotypes, the most dominant of which was called CJN-M [Ward RL, Knowlton DR, Schiff GM, Hoshino Y, Greenberg HB (1988) in J Virol 62: 1543-1549]. RNA-RNA hybridization and sequencing studies indicated that CJN was a typical G1P8 human rotavirus while CJN-M was a G1P5 strain and contained four gene segments (including segment 4) of a bovine rotavirus. Thus, the infant was apparently dually infected with human and bovine rotaviruses.     

Genetic variation in the VP7 gene of human rotavirus serotype 3 (G3 type) isolated in China and Japan

Sequence analysis of the VP7 gene was performed on twenty-one human isolates of serotype 3 related-rotavirus in China and Japan. The five Chinese isolates were found to be not similar to the 16 Japanese isolates and to SA11 (simian rotavirus). The Chinese isolates, especially CHW2 and CH-32, were different from the major serotype 3 human isolates. AU-1 and 02/92 which previously showed a wider spacing between RNA segments 10 and 11 by RNA polyacrylamide gel electrophoretic analysis, were more closely related to each other and could be differentiated from the other Chinese and Japanese isolates. For these reasons, serotype 3 viruses were considered to be intraserotypically more heterologous than serotype 1, 2 and 4 viruses.     

Increased Cat3-mediated cationic amino acid transport functionally compensates in Cat1 knockout cell lines

Arginine transport is important for a number of biological processes in vertebrates, and its transport may be rate-limiting for the production of nitric oxide. The majority of L-Arg transport is mediated by System y+, although several other carriers have been kinetically defined. System y+ cationic amino acid transport is mediated by proteins encoded by a family of genes, Cat1, Cat2, and Cat3. High affinity L-arginine transport was investigated in embryonic fibroblast cells derived from Cat1 knockout mice that lack functional Cat1. Both wild type and knockout cells transport arginine with comparable Km and Vmax. However, the apparent affinity for lysine transport was 2.4 times lower in Cat1(-/-) cells when compared with wild type cells, a property characteristic of Cat3-mediated transport. Northern analysis-documented Cat2 mRNA increased 2-fold, whereas Cat3 mRNA levels increased 11-fold in Cat1(-/-) relative to Cat1(+/+) cells. The low affinity Cat2a mRNA was not detectably expressed in these cells. Even though Cat3 expression is normally limited to adult brain, there was a large increase in the amount of Cat3 protein present at the plasma membrane of Cat1(-/-) embryonic fibroblast cells. These results suggest that Cat3 compensates for the loss of functional Cat1 in cells derived from Cat1 knockout mice and mediates the majority of high affinity arginine transport.     

Characterisation of G serotype dependent non-antibody inhibitors of rotavirus in normal mouse serum

Serotype specific (non-immunoglobulin) inhibitors of rotavirus have been identified in normal mouse serum obtained from BALB/c, CBA, and BL10 mice. Sialic acid was essential for the neutralising activity sera treated with the neuraminidase from Vibrio cholerae failed to neutralise rotavirus. G serotypes 4, 5, 7, 8, 9, and 10 were unaffected by the inhibitor(s) while G serotypes 1, 2, 6 and two G3 strains were neutralised to significant titres. Assessment of neutralisation of reassortants suggested that VP7 is the virus protein involved in the interaction although it remains possible that VP7 is influencing VP4 binding. Analysis of the sera by Western blot followed by virus overlay confirmed that binding is dependent on the presence of sialic acid. The human strain tested, Wa, bound to two (glyco) proteins (50 and 80 kDa) while the bovine strains tested, NCDV and UK bound to one (55 kDa) and two (36 and 55 kDa) proteins respectively. This indicates that while the bovine rotaviruses may bind to a common element, the human strain binds to clearly distinct proteins. We propose that these inhibitors interact with animal rotaviruses in a manner analogous to that by which they attach to target cells. The glycoprotein to which NCDV bound was purified and identified by N-terminal sequencing as murine alpha-1-anti-trypsin (MuAAT) and was confirmed to possess both neutralisation and anti-trypsin activity. Since MuAAT is known to possess only three N-linked glycans, identification and analysis of the actual virus-binding structure should now be possible.     

Epidemiology of symptomatic human rotaviruses in Bangalore and Mysore, India, from 1988 to 1994 as determined by electropherotype, subgroup and serotype analysis

Epidemiology of symptomatic rotaviruses from Bangalore and Mysore in Southern India was investigated. While serotype G3 predominated throughout the 7-year study period from 1988 to 1994 in Bangalore, serotype G1 was more predominant than serotype G3 in Mysore during 1993 and 1994. Serotype G2 strains were either not detected or infrequently observed in both the cities. However, several strains with subgroup I and 'short' RNA pattern that exhibited high reactivity with typing MAbs specific for serotype 2 as well as other serotypes were detected throughout the period. Among the nonserotypeable strains from both cities, several exhibited dual subgroup (SGI + II) or subgroup I specificity and 'long' RNA pattern indicating their probable animal origin. Notably, a gradual, yet highly significant reduction in rotavirus gastroenteritis, from 45.3% in 1988 to 1.8% during 1994, was observed in Bangalore in stark contrast to the consistently high (about 34%) incidence of asymptomatic infections among neonates by I321-like G10P11 type strains during the same period. Moreover, I321-like asymptomatic strains were not detected in children with diarrhea.     

Characterization of field strains of group A bovine rotaviruses by using polymerase chain reaction-generated G and P type-specific cDNA probes

Dot and Northern blot hybridization assays were used to analyze field strains of group A bovine rotaviruses (BRVs) by using nucleic acid probes representing P and G type specificities. The probes were prepared by polymerase chain reaction amplification of hyperdivergent regions of the cloned VP4 (nucleotides 211 to 686) and VP7 (nucleotides 51 to 392) genes from four serotypically distinct (in P or G types) strains of rotaviruses: NCDV (G6, P1), IND (G6, P5), 69M (G8, P10), and Cr (G10, P11). The P and G type cDNA probes were radiolabeled with [32P]dCTP and hybridized with RNA extracted from reference cell culture-passaged rotavirus strains or the field samples. The field samples were obtained from young diarrheic calves from Ohio, Nebraska, Washington State, and Canada. The cDNA probes were specific for their respective G or P types on the basis of analysis of known P and G type reference strains. The G typing analysis of 102 field samples revealed that 36.3% (37 of 102) were G6, 2.9% (3 of 102) were G8, 12.7% (13 of 102) were G10, and 23.5% (24 of 102) were untypeable. The P typing results for 93 samples indicated that 2.2% (2 of 93) were P1 (NCDV-like), 20.4% (19 of 93) were P5 (UK-like), 9.3% (10 of 93) were P11 (B223-like), and 40.8% (38 of 93) were untypeable. This is the first report of the identification among BRV strains in North America of a G type other than G6 or G10. Our report further confirms that G6, P5 rotaviruses are predominant among the BRV field strains that we examined, and the P types of these strains differ from that of the BRV vaccine strain used in the United States (G6, P1). The large number of untypeable G (23.5%) and P (40.8%) types suggests that other or new P and G types exist among BRV field strains.     

A molecular epidemiological study of porcine rotaviruses

15-20% of the CF mutation are expected to be rare and escape detection by systems designed to screen for common mutations. The highly polymorphic simple repeats would be particularly useful for genetic diagnosis in CF families where the mutations have not been identified. In this study, we used denaturing gradient gel electrophoresis with psoralen-modified oligonucleotide primers to study the GTnTm polymorphism previously identified at the intron 8 - exon 9 junction of the CFTR gene. Twelve characteristic patterns were identified. The most frequent genotype in CF alleles was GT10T9 and in non-CF alleles GT11T7. In this study, the heterozygous incidence is 70% in unrelated CF carriers. This polymorphism is full informative in 45% and half-informative in 50%. We conclude, that this polymorphism, easy to study by a relatively simple, rapid and cheap procedure, would be particularly useful in genetic counselling for CF and prenatal diagnosis in CF families in which mutations have not been yet identified.     

Enzyme-linked immunosorbent assay for measuring ileal symbiont intracellularis-specific immunoglobulin G response in sera of pigs

Proliferative enteritis (PE) is a common intestinal disease on pig farms. The disease is caused by ileal symbiont (IS) intracellularis (Campylobacter-like organisms) bacteria. An enzyme-linked immunosorbent assay (ELISA) was developed to measure IS intracellularis-specific immunoglobulin G (IgG) response in the sera of pigs. The antigen used in the ELISA was filtered, percoll gradient-purified IS intracellularis extracted from the intestines of pigs affected with proliferative hemorrhagic enteropathy. The antibody responses of pigs challenged with intestinal homogenates from pigs affected with proliferative hemorrhagic enteropathy containing IS intracellularis or percoll-gradient purified IS intracellularis were low and variable. The low IgG titers measured in challenged pigs support previous findings that IgG plays a minor role in the immune response of pigs to IS intracellularis. On a farm in which infection was endemic, pigs seroconverted at between 7 and 24 weeks of age. High IgG titers, indicative of maternally acquired antibody, were present in 3-week-old pigs. The IgG titers in piglets were lowest at 6 weeks of age, which approximates the age of onset of clinical disease. These results suggest that IgG plays a role in determining the susceptibilities of pigs to natural infection. Measurements of seroconversion by the ELISA might aid in epidemiological investigations of PE in naturally infected herds. However, the variable antibody responses in experimentally challenged pigs would seem to limit its usefulness as an antemortem diagnostic test for PE.     

Nigerian rotavirus serotype G8 could not be typed by PCR due to nucleotide mutation at the 3' end of the primer binding site

A rotavirus strain HMG89 from Nigeria with short electrophoretic pattern was typed G3 by PCR. A cDNA clone from the PCR product which hybridised in Northern blots to RNA segment 9 of the homologous Nigerian rotavirus strain HMG89 and laboratory reference strain 69M but not to other mammalian group A rotaviruses was sequenced. The VP7 gene 9 sequence is 1060 nucleotides long with two base deletions at positions 1034-1035. Sequence analysis of the primer (aAT8) used in the previous PCR serotyping assay revealed a mutation in one of the three nucleotide bases at the 3' end of the primer binding site accounting for our inability to serotype G8 strains in our samples. These findings demonstrate that PCR analysis can, albeit infrequently, lead to error in typing of rotaviruses due to small numbers of mutations in the primer binding region.     

Isolation of avian serotype 3 paramyxoviruses from imported caged birds in Israel

Ten avian serotype 3 paramyxoviruses were isolated for the first time in Israel from passerine and psittacine imported caged birds. The birds were submitted for investigation of an illness characterized by nonspecific signs of weakness, anorexia, vomiting, and sneezing. In addition, only the parakeets developed specific neurologic signs. In bacteriologic and pathologic investigation, cachexia and diarrhea were observed in both groups of birds. In psittacines, considerable alterations were observed in lungs, liver, and spleen. Some nonviral pathogens were occasionally isolated. The isolates appeared to belong to serotype 3b avian paramyxovirus (APMV), the prototype strain of which is APMV-3b/parakeet/Netherlands/449/75. The isolation of APMV-3 viruses from imported caged birds may represent a way of introduction of these viruses into the country.     

耐蚀合金G3、G3-Z和825热加工性的研究

用Thermomacmaster-Z热模拟机和TEM,SEM研究了G3(%:0.012C、46.51Ni、24.71Cr、8.88Mo、1.15W、1.72Cu、0.10Nb)、G3-Z(%:0.014C、46.53Ni、24.05Cr、6.89Mo、1.09W、1.70Cu)和825耐蚀合金(%:0.006C、43.77Ni、22.10Cr、3.24Mo、1.90Cu、0.86Ti)1 030～1 300℃、应变量(ε)0～0.8、应变速率1～2.5 s^-1的应力-应变曲线和温度对合金最大应力和断面收缩率的影响,并分析了合金发生动态再结晶的影响因素。结果表明,G3、G3-Z、825合金动态再结晶的晶粒大小随温度补偿系数Z的增大而减小;G3、G3-Z、825合金适宜的热加工温度范围分别为1 100～1 240℃、1 130～1 220℃和1 050～1 240℃。     

3G 智能手机三星 I9008

3G手机市场新品层出不穷,随着智能手机功能的不断强化,智能手机以成为移动办公中不可或缺的部分.三星新机19008 采用 4 英寸超大触摸屏设计,122.4×64.2×10.79mm的机身尺寸,124g的机身重量,纤薄轻巧为移动办公锦上添花.     

Receptor binding sites and antigenic epitopes on the fiber knob of human adenovirus serotype 3

The adenovirus fiber knob causes the first step in the interaction of adenovirus with cell membrane receptors. To obtain information on the receptor binding site(s), the interaction of labeled cell membrane proteins to synthetic peptides covering the adenovirus type 3 (Ad3) fiber knob was studied. Peptide P6 (amino acids [aa] 187 to 200), to a lesser extent P14 (aa 281 to 294), and probably P11 (aa 244 to 256) interacted specifically with cell membrane proteins, indicating that these peptides present cell receptor binding sites. Peptides P6, P11, and P14 span the D, G, and I beta-strands of the R-sheet, respectively. The other reactive peptides, P2 (aa 142 to 156), P3 (aa 153 to 167), and P16 (aa 300 to 319), probably do not present real receptor binding sites. The binding to these six peptides was inhibited by Ad3 virion and was independent of divalent cations. We have also screened the antigenic epitopes on the knob with recombinant Ad3 fiber, recombinant Ad3 fiber knob, and Ad3 virion-specific antisera by enzyme-linked immunosorbent assay. The main antigenic epitopes were presented by P3, P6, P12 (aa 254 to 269), P14, and especially the C-terminal P16. Peptides P14 and P16 of the Ad3 fiber knob were able to inhibit Ad3 infection of cells.     

Functional and structural analysis of the sialic acid-binding domain of rotaviruses

The infectivity of most animal rotaviruses is dependent on the interaction of the virus spike protein VP4 with a sialic acid (SA)-containing cell receptor, and the SA-binding domain of this protein has been mapped between amino acids 93 and 208 of its trypsin cleavage fragment VP8. To identify which residues in this region are essential for the SA-binding activity, we performed alanine mutagenesis of the rotavirus RRV VP8 expressed in bacteria as a fusion polypeptide with glutathione S-transferase. Tyrosines were primarily targeted since tyrosine has been involved in the interaction of other viral hemagglutinins with SA. Of the 15 substitutions carried out, 10 abolished the SA-dependent hemagglutination activity of the protein, as well as its ability to bind to glycophorin A in a solid-phase assay. However, only alanine substitutions for tyrosines 155 and 188 and for serine 190 did not affect the overall conformation of the protein, as judged by their interaction with a panel of conformationally sensitive neutralizing VP8 monoclonal antibodies (MAbs). These findings suggest that these three amino acids play an essential role in the SA-binding activity of the protein, presumably by interacting directly with the SA molecule. The predicted secondary structure of VP8 suggests that it is organized as 11 beta-strands separated by loops; in this model, Tyr-155 maps to loop 7 while Tyr-188 and Ser-190 map to loop 9. The close proximity of these two loops is also supported by previous results from competition experiments with neutralizing MAbs directed at RRV VP8.     

Differential tropism of EB rotavirus (serotype 3) to small intestine of homologous murine model

We are presenting the state of knowledge concerning intraoperative light-induced retinal injury, considered to be a combination of photic retinopathy and retinal photocoagulation. It may arise from retinal light exposure to the operating microscope or to the fiberoptic endoilluminator. Ultraviolet and short-wavelength visible light are more dangerous than longer wavelength light. Many risk factors may facilitate the onset of this iatrogenic disease following surgery. Many aspects of the retinal damage are still poorly understood. Many mid light-induced retinal injuries probably remain undiagnosed in routine postoperative examination. Current appropriate light filters are not the definitive solution. Appropriate precautions should be taken during both anterior segment and vitreoretinal surgery.     

Mutant alpha-subunit of the G protein G12 activates proliferation and inhibits differentiation of 3T3-F442A preadipocytes

We studied the G protein alpha-subunit Galpha12 in various tissues and cell lines. Significant amounts of Galpha12 were detected by immunoblots in liver, chromaffin cells, RINm5F cells, 3T3-F442A cells, and preadipocytes, but not in adipocytes, sperm, kidney, NB2A cells, or brain. To study the role of Galpha12 in adipose tissue differentiation, the preadipocyte cell line 3T3-F442A was transfected with wild-type Galpha12 or a constitutively activated mutant of Galpha12. Stable expression of the activated mutant of Galpha12 stimulated cell growth and inhibited preadipocyte differentiation. In contrast, wild-type Galpha12 overexpression inhibited preadipocyte differentiation, without any effect on cell proliferation. The role of Galpah12 on the Raf/MEK/mitogen-activating protein kinase (MAPK) cascade was studied. In confluent preadipocytes, expression of the activated mutant of Galpha12 induced an increase in B-Raf expression, but no change in MAPK activity. Differentiation was associated with a decrease in MAPK activity in control 3T3-F442A cells. Wild-type Galpha12 overexpression prevented the decrease in MAPK activity and induced MEK1, but not B-Raf, expression. Moreover, the activated mutant of Galpha12 induced an increase in MAPK activity and in the expression of both MEK1 and B-Raf. These data indicate that the activated mutant of Galpha12 stimulates the proliferation of 3T3-F442A preadipocytes, possibly through an increase in B-Raf expression, independently of the MEK/MAPK pathway, but prevents differentiation, probably through an increase in MEK1 expression and MAPK activity.     

A minor prevalent strain in a severe outbreak of foal diarrhea associated with serotype 3 rotavirus

An epizootic of foal diarrhea due to serotype 3 rotavirus (RV) was observed in 89 of 168 cases (53%) during the period from March to July in 1987. A total of 51 strains of RV were isolated from the 62 diarrheal feces examined, and one isolate (CH-3) showed a unique electropherotype of viral RNA which differed from the others that widely prevailed on this farm. No positive reaction was observed between strain CH-3 and each of the antisera against serotypes 1 to 12 of human and animal RV in neutralization tests. However, dsRNAs of the CH-3 virus were hybridized with a probe prepared from a strain of equine serotype 3 RV.