Importance of foot and mouth disease vaccine purity in interpreting serological surveys.

The aim of this study was to determine whether the degree of purity achieved in conventional vaccines against the foot and mouth disease virus in Argentina interferes with the interpretation of seroepidemiological surveys for confirming the absence of viral activity, which are performed to support the recognition of free zones practising vaccination. The evaluation of 168 vaccine series due to be marketed in Argentina (2006-2012) and subjected to official control testing in cattle, as well as repeated vaccination of cattle and other species using vaccines with high antigen concentrations, demonstrated that they did not induce antibodies to non-structural proteins (NSPs). The results show clearly that vaccines with satisfactory potency do not induce a response to NSPs, even by forcing the immune response through more concentrated doses with multiple valences and revaccination protocols at shorter irtervals than in vaccination campaigns. These results confirm that the vaccines used in routine vaccination programmes have a degree of antigen purification consistent with the needs observed on the basis of sampling for serological surveillance. Moreover, serological surveys conducted in 2006-2011 by Argentina's official Veterinary Services--the National Health and Agrifood Quality Service (SENASA)--on more than 23,000 sera per year from cattle included in the vaccination programme, in order to confirm the absence of virus circulation, revealed an average 0.05% of reactive results, consistent with the specificity of the tests. In conclusion, the vaccines produced by conventional methods and with proven potencythat are available in Argentina are sufficiently purified to ensure thatthey do not interfere with the interpretation of sampling for serological surveillance performed to support the recognition of FMD-free zones practising vaccination.

Local oceanographic variability influences the performance of juvenile abalone under climate change.

Climate change is causing warming, deoxygenation, and acidification of the global ocean. However, manifestation of climate change may vary at local scales due to oceanographic conditions. Variation in stressors, such as high temperature and low oxygen, at local scales may lead to variable biological responses and spatial refuges from climate impacts. We conducted outplant experiments at two locations separated by ~2.5 km and two sites at each location separated by ~200 m in the nearshore of Isla Natividad, Mexico to assess how local ocean conditions (warming and hypoxia) may affect juvenile abalone performance. Here, we show that abalone growth and mortality mapped to variability in stress exposure across sites and locations. These insights indicate that management decisions aimed at maintaining and recovering valuable marine species in the face of climate change need to be informed by local variability in environmental conditions.

Efficacy of a high quality O1/Campos foot-and-mouth disease vaccine upon challenge with a heterologous Korean O Mya98 lineage virus in pigs.

In 2010 serotype O foot-and-mouth disease virus of the Mya98 lineage/SEA topotype spread into most East Asian countries. During 2010-2011 it was responsible for major outbreaks in the Republic of Korea where a monovalent O/Manisa vaccine (belonging to the ME-SA topotype) was applied to help control the outbreaks. Subsequently, all susceptible animals were vaccinated every 6 months with a vaccine containing the O/Manisa antigen. Despite vaccination, the disease re-occurred in 2014 and afterwards almost annually. This study focuses on the in vivo efficacy in pigs of a high quality monovalent commercial O1/Campos vaccine against heterologous challenge with a representative 2015 isolate from the Jincheon Province of the Republic of Korea. Initially, viral characterizations and r1 determinations were performed on six viruses recovered in that region during 2014-2015, centering on their relationship with the well characterized and widely available O1/Campos vaccine strain. Genetic and antigenic analysis indicated a close similarity among 2014-2015 Korean isolates and with the previous 2010 virus, with distinct differences with the O1/Campos strain. Virus neutralisation tests using O1/Campos cattle and pig post vaccination sera and recent Korean outbreak viruses predicted acceptable cross-protection after a single vaccination, as indicated by r1 values, and in pigs, by expectancy of protection. In agreement with the in vitro estimates, in vivo challenge with a selected field isolate indicated that O1/Campos primo vaccinated pigs were protected, resulting in a PD50 value of nearly 10. The results indicated that good quality oil vaccines containing the O1/Campos strain can successfully be used against isolates belonging to the O Mya98/SEA topotype.

Antigenic and immunogenic spectrum of foot-and-mouth disease vaccine strain O1 Campos against representative viruses of topotypes that circulated in Asia over the past decade.

Identifying vaccine strains to control outbreaks of foot-and-mouth disease virus that could spread to new regions is essential for contingency plans. This is the first report on the antigenic/immunogenic relationships of the South American O1/Campos vaccine strain with representative isolates of the three currently active Asian type O topotypes. Virus neutralization tests using O1/Campos post-vaccination sera derived from cattle and pigs predicted for both species acceptable cross-protection, even after single vaccination, established by r1 values and by expectancy of protection using monovalent or polyvalent vaccines. The results indicate that effective oil vaccines containing the O1/Campos strain can be used against Asian isolates, expanding the scope of O1/Campos strain included in vaccine banks to control emergencies caused by Asian viruses, even on single-dose vaccination, and to cover the need of effective vaccines in Asia during systematic vaccination.

Rapid, small scale purification of rice hoja blanca and Echinochloa hoja blanca tenuivirus ribonucleoprotein.

Highly purified tenuivirus ribonucleoprotein was obtained from small amounts of leaf tissue by sedimenting the ribonucleoprotein particles from debris-free plant extract into a 30% sucrose cushion, in 1.5-mL microfuge tubes. Using this protocol, significant size differences were discovered in the double-stranded forms of the viral genomic RNAs of rice hoja blanca tenuivirus and a tenuivirus isolated from Echinochloa colonum, a common weed of rice cultivation.

A serological and biochemical study of new field isolates of foot-and-mouth disease virus type A in Peru, 1975 to 1981.

Three foot-and-mouth disease virus type A isolates recovered from field outbreaks in the Department of San Martin, Peru, during the period 1975 to 1981 were compared with each other, and the South American vaccine strains A24 and A27, by complement fixation (CF), virus neutralization (VN) and polyacrylamide gel electrophoresis (PAGE). Complement fixation and VN tests gave comparable results distinguishing the field isolates from each other and from the vaccine strains. Analysis of the structural polypeptides by PAGE also showed clear differences between all the viruses examined. Samples from tissue culture passaged and mouse adapted strains of one of the field isolates gave identical patterns in PAGE, but differences were observed in the polypeptide pattern of the A24/BRA/55 strain and the Peru vaccine strain, which were serologically indistinguishable. Results illustrate a continued antigenic variation in an endemic area where vaccination has been used; however, asymmetric serological reactions between the A24 vaccine strain and the most recent field isolate indicated that a vaccine incorporating A24 should still give adequate protection.

Plant regeneration of indica rice (Oryza sativa) cultivars from mature embryo-derived calli.

Plant regeneration from seven-week-old callus cultures derived from mature embryos of several indica rice cultivars was achieved with frequencies of morphogenic calli from 10 to 47%. Three media were tested both for callogenesis and plant regeneration. For 3 of the 7 genotypes examined, the best combination of media for plant regeneration was Murashige & Skoog basal medium: MSC (callogenesis) and MSR (regeneration). The rates of callogenesis were not related to the capacity for plant regeneration. Two genotypes CR-1113 and CR-5272 produced the highest number of regenerated green plants. The results of this study suggest that genetic differences could be directly linked to the ability to regenerate in these plant cultivars.

Sequence of the PV2 gene of rice hoja blanca tenuivirus RNA-2.

Comparison of a partial sequence of rice hoja blanca tenuivirus RNA-2 with 40% similarity to rice stripe tenuivirus RNA-2 revealed regions of high local sequence homology at the 5' terminus, within the coding region (the pv2 gene), and in the intergenic region separating this gene from the other protein (pc2) encoded by this ambisense RNA. Analysis of the conserved regions of the pv2 protein identified two motifs found principally in viral membrane glycoproteins and six motifs found each in a wide variety of proteins. The possible significance of these results is discussed.

Cauliflower mosaic virus gene II product forms distinct inclusion bodies in infected plant cells.

Turnip leaves infected with the aphid transmissible isolate of cauliflower mosaic virus (CaMV Cabb B-JI) showed two types of virus-containing inclusion bodies (IBs), which differed morphologically and in their protein composition when analyzed by immunogold labeling of ultrathin sections. Vacuolated IBs, typical of CaMV infections, contained P62 (the generally accepted IB protein) but lacked P18 (the aphid transmission factor), while electron-lucent IBs did not contain P62 but were the only detectable sites of P18 accumulation within the infected leaf cells. Both types of inclusions were detected in cells of the epidermis, vascular bundles, mesophyll, and spongy parenchyma. Electron-lucent IBs were not found in the aphid nontransmissible isolates of CaMV, Campbell and CM4-184.

Alpha 2-agonists block ADH action in toad bladder and this inhibition is not modified by indomethacin.

To identify the type of alpha-adrenoceptors involved in the inhibition of the hydrosmotic effect of antidiuretic hormone (ADH) on the toad bladder, we studied the effect of different alpha-adrenergic agonists and antagonists on ADH-induced water transport. Serosal addition of epinephrine (10(-6) M) and norepinephrine (10(-6) M) in the presence of 10(-4) M propranolol significantly inhibited the hydrosmotic effect of ADH (arginine vasopressin). This inhibitory effect of the catecholamines was completely reversed by 10(-5) M yohimbine but not by prazosin. Clonidine did not block ADH-induced water transport, but guanabenz, another alpha 2-agonist, inhibited water transport in response to ADH. In bladders pretreated with indomethacin to block prostaglandin synthesis, basal water permeability was increased, and even in this condition epinephrine inhibited ADH-induced water transport. These studies indicate that alpha 2-adrenergic receptors are involved in the inhibitory effect of catecholamines on ADH-mediated water permeability in the toad bladder. However, this effect was not mimicked by clonidine, as in the case of rabbit cortical collecting tubule. The inhibitory effect of epinephrine appears to be exerted independently of prostaglandin synthesis.

Comparative in vitro activity of a new fluorinated 4-quinolone, T-3262 (A-60969).

The in vitro activity of a new quinolone, T-3262 [A-60969; DL-7-(3-amino-1-pyrrolidinyl)-1-(2,4-difluorophenyl)-6-fluoro-1-, 4-dihydro-4-oxo-1,8-naphthyridine-3-carboxylic acid monohydrate], was compared with those of ciprofloxacin, ofloxacin, ceftazidime, imipenem, and gentamicin. T-3262 inhibited 90% of isolates of the family Enterobacteriaceae at a concentration of less than or equal to 0.25 micrograms/ml. It was two to four times more active than ofloxacin and similarly or slightly less active than ciprofloxacin. Ninety percent of isolates of Pseudomonas aeruginosa were inhibited at 0.5 micrograms/ml. It was 4- to 8-fold more active than ciprofloxacin and 8- to 16-fold more active than ofloxacin against Pseudomonas cepacia and Pseudomonas maltophilia, which were resistant to imipenem and gentamicin. Most Haemophilus influenzae, Neisseria gonorrhoeae, and Branhamella catarrhalis isolates were inhibited at concentrations of less than or equal to 0.008 micrograms/ml. The MIC for 90% of the Staphylococcus aureus isolates, including methicillin-resistant S. aureus, was 0.12 micrograms/ml; that for Staphylococcus epidermidis was 0.5 micrograms/ml, as was that for Enterococcus faecalis. It inhibited 90% of Bacteroides fragilis isolates at 2 micrograms/ml, considerably more active than ciprofloxacin and ofloxacin. The frequency of spontaneous point mutational resistance was less than 10(-10) for members of the family Enterobacteriaceae and Pseudomonas spp. Resistant strains could be selected by repeated subculture. Similar to other quinolones, its activity could be affected by culture conditions. T-3262 showed a postantibiotic suppressive effect on Escherichia coli, P. aeruginosa, and S. aureus.

Effect of a simultaneous potassium and carbohydrate load on extrarenal K homeostasis in end-stage renal failure.

Patients with chronic renal failure (CRF) are continuously exposed to hyperkalemia. In these patients the extrarenal disposal of a potassium load may be very important to determine the plasma potassium levels. We studied the effect of a combined oral load of potassium (0.5 mEq/kg body weight) and carbohydrate (0.5 g/kg body weight) to mimic normal ingestion of potassium. Eight CRF patients and 5 control subjects were studied. The maximal increase in plasma potassium levels achieved was significantly higher in the patients (1.07 +/- 0.1 mEq/l) than in controls (0.39 +/- 0.05 mEq/l). Basal insulin levels were higher in the CRF patients and increased with the oral potassium and carbohydrate load in both controls and patients. In the CRF patients only 58.9 +/- 3% of the potassium load was translocated to the intracellular space compared to 81 +/- 6% in the controls. No correlation was found between the acid base status and maximal potassium increase. We conclude that patients with CRF exhibit an impaired extrarenal handling of potassium and that this abnormality does not appear to be related to insulin secretion or acid base status.

Sequence analysis of rice hoja blanca virus RNA 3.

RNA 3 of rice hoja blanca tenuivirus (RHBV) has 2299 nucleotides and resembles RNA 3 of other tenuiviruses such as maize stripe (MStV) and rice stripe (RStV) viruses in potentially coding with an ambisense strategy for two proteins. Both the viral-sense protein of 23K and the complementary-sense protein of 35K have about 46% amino acid identity with the analogous proteins encoded by RNA 3 of MStV and RStV. As the proteins of MStV and RStV have about 65% identity between themselves, RHBV cannot be a South and Central American strain of the Asian RStV. The intergenic region resembles those of other tenuiviruses, being rich in A and U residues, but its predicted folding pattern is unlike those of other tenuiviruses. Instead, the predicted folding of the intergenic region was indistinguishable from that of the coding regions and there was no evidence for a distinct hairpin-loop structure. The significance to the evolution of tenuiviruses of the similarities that the two proteins have with their analogues in other tenuiviruses is discussed.

In situ immunogold labeling analysis of the rice hoja blanca virus nucleoprotein and major noncapsid protein.

Ribonucleoprotein particles (RNPs) of rice hoja blanca virus (RHBV) were purified and used for electron microscopic analysis and antibody production. Antibodies made to RNPs specifically decorated purified RNPs. The RNPs typically showed characteristic tenuivirus morphologies. They were approximately 8 nm in diameter, mostly circular in nature, and exhibited branching and a high degree of superhelicity. When the RNP antibodies were used for in situ immunogold labeling analysis of RHBV-infected tissues, no specific structures were identified, but gold particles were distributed throughout the cytosol of RHBV-infected but not healthy plants. However, amorphous semi-electron opaque inclusion bodies (ASO-IBs) were abundant in cells of RHBV-infected plants. While the ASO-IBs were not labeled with the anti-RNP antiserum, they were specifically labeled with antibodies to the RHBV major noncapsid protein (NCP) and with antibodies to the NCP of another tenuivirus, maize stripe virus.

Phylogenetic placement of a novel tenuivirus from the grass Urochloa plantaginea.

Evidence is presented that a tenuivirus recovered from the grass Urochloa plantaginea is probably a novel tenuivirus species, to be called Urochloa hoja blanca virus (UHBV). It is related to both Echinochloa hoja blanca virus (EHBV) and Rice hoja blanca virus (RHBV), and these three form a group distinct from Maize stripe virus (MStV) and Rice stripe virus (RStV). Phylogenetic analysis of the sequence data for RNA-3 and RNA-4 of these viruses supports the hypothesis that EHBV and UHBV may have evolved from an ancestral form of RHBV, precipitated by the introduction of Echinochloa colona and Urochloa plantaginea to America.

Sequence of rice hoja blanca tenuivirus RNA-2.

The sequence of rice hoja blanca tenuivirus RNA-2 is analysed and compared to its counter-part in rice stripe tenuivirus. The RNA encodes two proteins, in an ambisense arrangement. The 94 kD pc2, located in the complementary sense RNA, has several features typical of viral membrane (glyco)proteins, and also has regions of local homology to the glycoproteins of the Phleboviruses (Bunyaviridae). The 23 kD pv2 lies in the viral sense RNA and has two small conserved domains that are almost exclusively found in retro-viral membrane glycoproteins. Its genome location is analogous to the NSm protein of several of the Bunyaviridae species, which is thought to have a membrane-related function. The two open reading frames are separated by a large intergenic region which, in common with the other tenuivirus ambisense RNA segments, has a short region that is highly conserved between RStV and RHBV. The significance of these results with respect to the virus structure and gene expression is discussed.

Sequence of echinochloa hoja blanca tenuivirus RNA-5.

The sequence is presented of RNA-5 of Echinochloa hoja blanca tenuivirus, a second tenuivirus associated with rice cultivation in Latin America (after rice hoja blanca virus). The RNA is 1334 nucleotides long and contains in the complementary sense RNA a single long open reading frame. The deduced amino acid sequence of this open reading frame shows that it encodes a highly basic and hydrophilic 44 kD protein (pc5) with about 50% similarity to the pc5 protein of maize stripe virus (MStV). This and other features of the RNA are discussed.

Sequence of Echinochloa hoja blanca tenuivirus RNA-4.

The sequence is presented of RNA-4 of Echinochloa hoja blanca tenuivirus (EHBV), one of two tenuiviruses associated with rice cultivation in Latin America (together with rice hoja blanca virus; RHBV). Analysis of the sequence shows that the coding regions of EHBV RNA-4 are closely related to those of RHBV RNA-4. However, the intergenic region separating the two ambisense open reading frames, are highly distinct for the two viruses. The features of the RNA and the comparisons with the sequences of RNA-4 of RHBV, rice stripe virus (RStV) and maize stripe virus (MStV) are discussed.

Sequence of Echinochloa hoja blanca tenuivirus RNA-3.

Analysis of the sequence of the 2336 nucleotide RNA-3 of Echinochloa hoja blanca tenuivirus shows that it is closely related to RNA-3 of rice hoja blanca tenuivirus, the principal virus disease of rice in Latin America. This is especially true for the coding regions, where the viruses are almost 90% similar. However, the non-coding regions of RNA-3 of these viruses, principally the intergenic region separating the two ambisense open reading frames, are only about 50% similar, suggesting that these are distinct viruses. The results closely resemble those obtained for the analysis of RNA-4 of these viruses, both in the absolute and relative percentage similarities of the coding and non-coding regions. This implies a coordinated evolution of the different tenuivirus RNA segments. The features of the RNA and the comparisons with the sequences of RNA-3 of RHBV, rice stripe virus (RStV) and maize stripe virus (MStV) are discussed.

Mitochondrial changes during the apoptotic process of HeLa cells exposed to cisplatin.

HeLa cells undergo apoptosis after exposure to cisplatin. Since mitochondria have recently been proposed as a probable effector of this type of cell death, we performed an analysis using the fluorescent cation rhodamine 123, which is transported actively by this organelle. Cisplatin induces a decrease in the mitochondrial staining, as assessed by cytofluorometric analysis. Microscopic analysis demonstrated that this effect was accompanied by damage of the mitochondria. These features were not exclusive of cisplatin, as other antineoplasic agents (taxol, etoposide) elicited similar effects. These results point toward the notion of a general effect of antineoplasic drugs over the mitochondria during induction of apoptotic cell death.