Detection of classical swine fever vaccine virus in blood and tissue samples of pigs vaccinated either with a conventional C-strain vaccine or a modified live marker vaccine

Attenuated live classical swine fever (CSF) viruses are the most efficacious vaccines against the disease. However, little is known about the distribution and detection of CSF vaccine viruses in the host. We therefore compared the new recombinant attenuated marker vaccine virus CP7_E2alf with the conventional C-strain vaccine concerning virus isolation, antigen-, and genome-detection in different samples within the first 42 days post-vaccination (p.v.). Leukocytes and several organs such as tonsils, lymph nodes, spleen, thymus, parotis and kidney were also tested using highly sensitive real-time reverse transcription-polymerase chain reaction (RT-PCR) techniques. It was demonstrated that vaccine virus could be detected by live animal sampling only in a few leukocytes samples at very low titres and genome copy numbers within the first 14 days after immunisation. Vaccine virus could also be isolated from individual tonsil samples within the first 6 days after vaccine application. In contrast, vaccine virus genomes were consistently detected in the tonsils up to day 42 by real-time RT-PCR. Distribution, amount of virus and viral genome levels were similar for both tested vaccines. In conclusion, blood samples could be the sample material of choice for detecting CSF wild type virus infection even in vaccinated animals after more than 14 days p.v., while tonsil sampling provided appropriate material for long-term detection of both tested CSF vaccine viruses using real-time RT-PCR methods.

Virulence, immunogenicity and vaccine properties of a novel chimeric pestivirus

A chimeric pestivirus of border disease virus Gifhorn and bovine viral diarrhea virus CP7 (Meyers et al., 1996) was constructed. Virulence, immunogenicity and vaccine properties of the chimeric virus were studied in a vaccination-challenge experiment in pigs. The chimeric virus proved to be avirulent and neither chimeric virus nor viral RNA was detected in serum after vaccination. The safety of the vaccine was tested by horizontal transmission to sentinel pigs, which remained uninfected. The vaccine efficacy was examined by challenge infection with classical swine fever virus (CSFV) Eystrup. In 'challenge controls', the viral load of CSFV coincided with the development of pronounced clinical symptoms. In contrast, the vaccinated pigs showed transient and weak clinical signs. Analysis of the viral load in these pigs showed 1000-fold lower viral RNA levels compared to 'challenge controls' and horizontal transmission of challenge virus to sentinel pigs was not observed.

CP7_E2alf: a safe and efficient marker vaccine strain for oral immunisation of wild boar against Classical swine fever virus (CSFV)

Wild boar are an important reservoir of Classical swine fever virus (CSFV) in several European countries, where most of the primary outbreaks in domestic pigs are directly related to the endemic disease situation in the wild boar population. Oral immunisation has been introduced as an additional control measure to accelerate CSF eradication in wild boar in Germany since 1993. Immunisation with an oral bait vaccine based on the conventionally attenuated live vaccine strain "C" proved to be safe and effective, but does not allow differentiation between infected and vaccinated animals. Therefore, we examined the vaccine efficacy of the recently constructed chimeric pestivirus CP7_E2alf, whose coding sequences for the major envelope protein E2 of BVDV strain CP7 are replaced by E2 of the CSFV strain Alfort187 [Reimann I, Depner K, Trapp S, Beer M. An avirulent chimeric pestivirus with altered cell tropism protects pigs against lethal infection with classical swine fever virus. Virology 2004;322(1):143-57]. Following oral immunisation of wild boar, CP7_E2alf proved to be completely avirulent. Furthermore, all vaccinees were fully protected from clinical disease after a highly virulent CSFV challenge infection. The immunised animals seroconverted within 3 weeks after vaccination for CSFV E2-specific and CSFV neutralising antibodies, whereas prior to challenge infection no antibodies against CSFV E(rns) were detected with an appropriate CSFV-specific marker ELISA test. Thus, the BVDV backbone of CP7_E2alf enables serological and genetic differentiation from wild type CSFV infection. In conclusion, CP7_E2alf represents the first efficient and safe marker vaccine candidate for oral immunisation of wild boar against CSFV.

Novel marker vaccines against classical swine fever

Classical swine fever (CSF) is one of the most devastating epizootic diseases of pigs worldwide. For eradication and control purposes, CSF vaccination is an important tool, and efficacious and safe attenuated vaccines have been available for many decades (for example, the C-strain vaccines). In addition to administering them parenterally, live attenuated vaccines are also administered orally for the control and eradication of CSF in wild boar populations. However, antibodies against live attenuated vaccines do not allow to differentiate infected from vaccinated animals (DIVA principle) and the mechanism responsible for attenuation is not known. Only a few years ago the first DIVA vaccines based on baculovirus-expressed E2 glycoprotein have been put on the market [Hulst MM, Westra DF, Wensvoort G, Moormann RJ. Glycoprotein E1 of hog cholera virus expressed in insect cells protects swine from hog cholera. J Virol 1993;67(9):5435-42]. However, these subunit E2 marker vaccines are less efficient and more than one parenteral application is necessary. Furthermore, oral vaccination is not possible. Taking these disadvantages into account, the development of novel CSF vaccines has been focussed on five different strategies, mainly based on genetically engineered constructs: (1) immunogenic CSFV peptides, (2) DNA vaccines, (3) viral vectors expressing CSFV proteins, (4) chimeric pestiviruses, and (5) trans-complemented deleted CSFV genomes (replicons).

An avirulent chimeric Pestivirus with altered cell tropism protects pigs against lethal infection with classical swine fever virus

A chimeric Pestivirus was constructed using an infectious cDNA clone of bovine viral diarrhea virus (BVDV) [J. Virol. 70 (1996) 8606]. After deletion of the envelope protein E2-encoding region, the respective sequence of classical swine fever virus (CSFV) strain Alfort 187 was inserted in-frame resulting in plasmid pA/CP7_E2alf. After transfection of in vitro-transcribed CP7_E2alf RNA, autonomous replication of chimeric RNA in bovine and porcine cell cultures was observed. Efficient growth of chimeric CP7_E2alf virus, however, could only be demonstrated on porcine cells, and in contrast to the parental BVDV strain CP7, CP7_E2alf only inefficiently infected and propagated in bovine cells. The virulence, immunogenicity, and "marker vaccine" properties of the generated chimeric CP7_E2alf virus were determined in an animal experiment using 27 pigs. After intramuscular inoculation of 1 x 10(7) TCID(50), CP7_E2alf proved to be completely avirulent, and neither viremia nor virus transmission to contact animals was observed; however, CSFV-specific neutralizing antibodies were detected from day 11 after inoculation. In addition, sera from all animals reacted positive in an E2-specific CSFV-antibody ELISA, but were negative for CSFV-E(RNS)-specific antibodies as determined with a CSFV marker ELISA. After challenge infection with highly virulent CSFV strain Eystrup, pigs immunized with CP7_E2alf were fully protected against clinical signs of CSFV infection, viremia, and shedding of challenge virus, and almost all animals scored positive in a CSFV marker ELISA. From our results, we conclude that chimeric CP7_E2alf may not only serve as a tool for a better understanding of Pestivirus attachment, entry, and assembly, but also represents an innocuous and efficacious modified live CSFV "marker vaccine".

Trans-complementation of autonomously replicating Bovine viral diarrhea virus replicons with deletions in the E2 coding region

Autonomously replicating Bovine viral diarrhea virus (BVDV) genomes (replicons) were constructed from the full-length BVDV cDNA clone pA/BVDV/Ins- (G. Meyers et al., J. Virol. 70, 8606-8613, 1996). The sequences coding for envelope protein E2, for E2 without the C-terminal transmembrane region, or for E2 and nonstructural protein p7 were deleted, and the resulting mutants were tested for their ability to replicate after transfection. All deletion mutants were able to replicate and to express the inserted green fluorescent protein but did not produce infectious progeny virus in bovine kidney PT cells. The replicons were also tested for their ability to be trans-complemented in the bovine cell line PT_805, which constitutively expresses BVDV structural proteins. E2-negative BVDV mutants were complemented and >10(6) infectious units were obtained at 24 h after transfection. Complementing PT_805 cells could only inefficiently be infected using trans-complemented virions, however, and low levels of virus production were observed when complemented BVDV was passaged using PT_805 cells. Similarly, infection of PT_805 cells with BVDV was highly inefficient, but transfection of full-length BVDV NCP7 RNA into PT_805 resulted in 10,000-fold higher virus titers when compared to those obtained 24 h after transfection of parental PT cells. We concluded that self-replicating E2-deleted BVDV RNAs can be efficiently trans-complemented by constitutively expressed E2, and that expression of BVDV structural proteins markedly influences susceptibility of cells to BVDV infection as well as BVDV titers after transfection of full-length BVDV RNA.

Cattle Infected with Bovine Leukaemia Virus may not only Develop Persistent B-cell Lymphocytosis but also Persistent B-cell Lymphopenia

We investigated the distribution of B and T cells in the peripheral blood of haematologically inconspicuous (non-persistent lymphocytotic, PL-) cattle infected with the bovine leukaemia virus (BLV). Flow cytometric data were obtained from six PL- cattle and compared with six age-matched animals with persistent lymphocytosis (PL+) and five non-infected healthy controls (BLV-). In the PL- group, the percentage and number of surface immunoglobulin-positive (sIg+) B cells were significantly reduced. Whereas in BLV-cattle, about 40% of the peripheral blood lymphocytes (PBL) were sIg + and 24% were sIgM + B cells. In the PL- group, less than 20% of the PBL were sIg+ and sIgM+ B cells. Only 5% of the PBL co-expressed sIgM+ and CD5+ versus 16% in BLV-. This decrease was persistent over 3 years and predominantly affected: (i) B cells that did not express sIgM; (ii) sIgM + B cells co-expressing CD5 and CD11b; and (iii) equally both lambda- and K-type light chain B-cell subpopulations. In contrast, the number of all circulating lymphocytes, CD5- and CD11b- sIgM+ B cells and CD2+ T cells did not differ. In PL+ animals, about 75% of the PBL were sIgM+ CD5+ B cells. These cells were of polyclonal origin, as light chains of the lambda- and K-type were expressed in a ratio of 4:1 (57.7% of PBL lambda+, 14% kappa+) as in BLV- animals (33.6% of PBL lambda+, 8.7% kappa+). In PL+ cattle the absolute number of B-cells and, therefore, their relative percentage is significantly increased. For this reason, even in case of absolutely increased T-cell numbers, the relative percentage of T-cells could be lower than in normal controls. The cause for the observed B cell decrease in PL- cattle is unknown, but it can be assumed that cytotoxic T cells are involved in this B-cell lymphopenia.

In vitro and in vivo expression of foreign genes by transmissible gastroenteritis coronavirus-derived minigenomes

A helper-dependent expression system based on transmissible gastroenteritis coronavirus (TGEV) has been developed using a minigenome of 3.9 kb (M39). Expression of the reporter gene beta-glucuronidase (GUS) (2-8 microg per 10(6) cells) and the porcine respiratory and reproductive syndrome virus (PRRSV) ORF5 (1-2 microg per 10(6) cells) has been shown using a TGEV-derived minigenome. GUS expression levels increased about eightfold with the m.o.i. and were maintained for more than eight passages in cell culture. Nevertheless, instability of the GUS and ORF5 subgenomic mRNAs was observed from passages five and four, respectively. About a quarter of the cells in culture expressing the helper virus also produced the reporter gene as determined by studying GUS mRNA production by in situ hybridization or immunodetection to visualize the protein synthesized. Expression of GUS was detected in the lungs, but not in the gut, of swine immunized with the virus vector. Around a quarter of lung cells showing replication of the helper virus were also positive for the reporter gene. Interestingly, strong humoral immune responses to both GUS and PRRSV ORF5 were induced in swine with this virus vector. The large cloning capacity and the tissue specificity of the TGEV-derived minigenomes suggest that these virus vectors are very promising for vaccine development.

Subacute liver necrosis after experimental infection with rabbit haemorrhagic disease virus (RHDV)

Rabbit haemorrhagic disease (RHD) is usually peracute to acute, while subacute to chronic disease is rare. This paper describes gross and histopathological findings in four out of 20 rabbits aged 14 weeks, experimentally infected with one of two German field isolates of RHD virus. Eight rabbits survived the infection for 10 days and were killed after four of them, infected with 100 to 10 000 haemagglutination units, had started to develop progressive jaundice. Histopathologically, icteric livers showed severe subacute centrilobular bridging necrosis with calcification, and proliferation of periportal hepatocytes and bile ducts. Positive-strand RHDV RNA was detected by in-situ hybridization, mainly in periportal macrophages. Loss of the normal hepatic architecture, reparation (fibrosis) and hepatocellular regeneration, together with moderate inflammatory reaction, are signs of liver cirrhosis. These signs, observed in young rabbits given small doses of RHD virus, are interpreted as an unusual outcome of experimental inoculation.

[Gunshot wounds in a historical light]

At the beginning of the Renaissance the advent of firearms really progressed. The injuries needed new methods of treatment. Due to the high incidence of infection and the theory of poisoning an increased interest to remove the bullets with probes and forceps was seen. However, improvement in the treatment did not occur until the middle of the 19th century, when anaesthesia and antiseptic were generally known. The Medical History Museum has the disposal of a representative selection of instruments to remove bullets from gunshot wounds. A description concerning their origin as well as function is given.

[From the collection of instruments at the Museum of medical history. Tourniquets and compressors]

This article calls attention to the extensiveness of our collection of instruments we have chosen to publish a description of the tourniquets and compressors. The era of these instruments is limited, that is to say from the discovery by Morel in 1674 to Esmarch about 1870. The many different types mentioned in the literature are richly represented. They are named after the originators, who were the great surgeons and instrumentmakers at that time. In the oldest existing list of the instruments dated from 1760 more of the tourniquets are recorded, others are included in a protocol dated 1875. A hand-written book with lecture-notes from 1860 shows evidence of the level of education in surgery.

Opipramol for the treatment of somatoform disorders results from a placebo-controlled trial

Although somatoform disorders are highly prevalent, so far there is no established pharmacological treatment. Opipramol is a psychopharmacon widely prescribed in Germany. Early trials with opipramol showed the drug's effectiveness in anxiety states coupled with somatic complaints. Therefore, the efficacy of opipramol in somatoform disorders was evaluated using adequate clinical trial methods. A multicentre, randomized, 6-week, placebo-controlled clinical trial was performed in a total of 200 patients suffering from somatoform disorders according to ICD-10. In the main outcome criterion, the somatic subscore of the Hamilton Anxiety Scale, and in nearly all other outcome criteria opipramol (200 mg/day) was statistically more effective than placebo. A similar number of adverse events was noted in both groups. The results of this first-placebo-controlled study in somatoform disorders suggest efficacy of opipramol in this indication but need replication.

Pathogenic, antigenic and molecular properties of rabbit haemorrhagic disease virus (RHDV) isolated from vaccinated rabbits: detection and characterization of antigenic variants

Rabbit haemorrhagic disease virus (RHDV) isolates were obtained from several animals previously vaccinated with an inactivated vaccine. Seven isolates were analyzed by immunological and molecular biological methods and compared to reference strains. Antigenic characterization with monoclonal antibodies as well as haemagglutination assays demonstrated considerable differences between individual isolates. However, sequencing of the capsid protein genes revealed a high degree of homology between five of these isolates and the reference strain FRG. In contrast, two isolates specified remarkably different capsid proteins with a degree of variation not observed so far in RHDV. Amino acid alterations were found clustered between residues 301 and 328 (region C), 344 and 434 (region E) and also in the 3' region of the capsid protein gene. Interestingly, experimental vaccination of rabbits followed by challenge with the heterologous variant strains showed restricted cross-protection against one of the strains. In summary, we found a level of antigenic variation not detected in RHDV so far, and describe two distinct new antigenic variants.

Tissue-specific translational regulation of alternative rabbit 15-lipoxygenase mRNAs differing in their 3'-untranslated regions

By screening a rabbit reticulocyte library, an alternative 15-LOX transcript of 3.6 kb (15-LOX mRNA2) was detected containing a 1019 nt longer 3'-untranslated region (UTR2) than the main 2.6 kb mRNA (15-LOX mRNA1). In anaemic animals, northern blotting showed that 15-LOX mRNA2 was predominantly expressed in non-erythroid tissues, whereas 15-LOX mRNA1 was exclusively expressed in red blood cells and bone marrow. The 15-LOX 3'-UTR2 mRNA2 contained a novel 8-fold repetitive CU-rich motif, 23 nt in length (DICE2). This motif is related but not identical to the 10-fold repetitive differentiation control element (DICE1) of 19 nt residing in the 15-LOX UTR1 mRNA1. DICE1 was shown to interact with human hnRNP proteins E1 and K, thereby inhibiting translation. From tissues expressing the long 15-LOX mRNA2, two to three unidentified polypeptides with molecular weights of 53-55 and 90-93 kDa which bound to DICE2 were isolated by RNA affinity chromatography. A 93 kDa protein from lung cytosol, which was selected by DICE2 binding, was able to suppress translational inhibition of 15-LOX mRNA2, but not of 15-LOX mRNA1, by hnRNP E1. A possible interaction between DICE1/DICE2 cis / trans factors in translational control of 15-LOX synthesis is discussed. Furthermore, the 3'-terminal part of the highly related rabbit leukocyte-type 12-LOX gene was analysed. Very similar repetitive CU-rich elements of the type DICE1 (20 repeats) and DICE2 (nine repeats) were found in the part corresponding to the 3'-UTR of the mRNA.

Simultaneous expression of leukocyte-type 12-lipoxygenase and reticulocyte-type 15-lipoxygenase in rabbits

In rabbit reticulocytes an arachidonic acid 15-lipoxygenase (15-LOX) is expressed at high yield. Rescreening a rabbit reticulocyte cDNA library for alternative 15-LOX transcripts, a full length cDNA which encodes a novel lipoxygenase was isolated. The predicted amino acid sequence of this enzyme shared a high degree (99%) of identity with the reticulocyte-type 15-lipoxygenase. Among the six amino acid residues different in both enzymes a Phe-Leu exchange was detected at position 353. Recently, site-directed mutagenesis studies have revealed that this amino acid exchange converts a 15-lipoxygenase to a 12-lipoxygenase. In fact, when the novel enzyme was expressed in Escherichia coli, mainly 12-lipoxygenation of arachidonic acid was observed. The recombinant enzyme exhibited a rather broad substrate specificity. Various C-18 and C-20 polyenoic fatty acids and even complex substrates such as biomembranes were effectively oxygenated. Thus, the novel enzyme may be classified as leukocyte-type 12-lipoxygenase. Genomic polymerase chain reaction of the 3' region of the leukocyte-type 12-lipoxygenase gene indicated that introns 10 to 13 differed to about 10% from the corresponding sequences of the 15-lipoxygenase gene although their size and the intron-exon organization were very similar. In the 3'-untranslated region of the novel mRNA a C+U-rich, 20-fold repetitive element was found which appears to be highly related to the differentiation control element of the 15-lipoxygenase mRNA. Activity assays with a variety of cells and tissues prepared from normal rabbits suggested that only peripheral monocytes abundantly express the enzyme, suggesting a tissue-specific regulation of gene expression. These data indicate for the first time the co-expression of two separate genes for a reticulocyte-type 15-lipoxygenase and for a leukocyte-type 12-lipoxygenase in one species. This is of importance for the implication of both enzymes in red blood cell development and atherogenesis.

Human bone bank allografts stimulate bone resorption and inhibit proliferation in cultures of human osteoblast-like cells

Incorporation of a frozen human bone allograft requires osteoclast activity and ingrowth of recipient osteoblast precursors. We examined the effects of allografts on human osteoblasts. Allografts stimulated a release of factors from normal human osteoblast-like cells, capable of inducing osteoclastic bone resorption in vivo. Further allografts inhibited osteoblast proliferation in cultures. The response was detectable within 4 days of culture and was still present after 3 weeks. Devitalized bone autografts had a similar effect. This suggests that bone bank grafts may induce a resorptive reaction at the recipient site by stimulating release of factors from osteoblasts capable of inducing osteoclastic resorption. The storage temperature was crucial for preservation of the response, since the activity was lower in allografts stored for 6 months at -20 degrees C than in those stored at -80 degrees C.

Use of the polymerase chain reaction for the detection of reticuloendotheliosis virus in Marek's disease vaccines and chicken tissues

Reticuloendotheliosis virus (REV) proviral DNA appears to be a frequent contaminant in Marek's disease (MD) vaccines. A polymerase chain reaction (PCR) was established and evaluated for its ability to detect REV proviral DNA in infected cell cultures and chicken tissues. Deoxynucleotide primers were selected from the highly conserved gag region of the REV genome. The amplification products were identified by electrophoresis, nested PCR and by hybridization with a digoxigenine-labelled oligonucleotide. The PCR results correlated well with the diagnosis obtained by conventional procedures, i.e. virus isolation or indirect immuno-fluorescence test (IIFT).

Application of the photoionization detector for the determination of ethanol in aqueous solutions and human breath

A determination of ethanol is described, which is based on a purging system in conjunction with a photoionization detector. With that system a fast and reliable determination of ethanol in aqueous solutions is possible. The system has been used for the analysis of wine. The 3delta-detection limit has been 0.005% ethanol, the relative standard deviation 4.8 to 6.0% and the time constant of the entire analytical system 20 s. The photoionization detector has been also applied to the analysis of artificial and genuine human breath. A comparison with gas-chromatography and non-dispersive IR-detection has been proven the reliability of results.

Bone banking in Denmark, results of a nationwide survey

In a nationwide survey, all orthopaedic clinics were surveyed via a questionnaire about the use of bone allografts and how they managed their bone banks. Thirty-two clinics (100 per cent) responded to the questionnaire (mid 1991). Seventeen clinics had established bone banks on the basis of femoral heads obtained from donors during primary hip replacement. Only five used bone substitutes. The mean consumption was 30 capita per year (10-132) and ten clinics estimated an increasing demand for allografts. The storage method was by freezing at temperatures varying from minus 20 to minus 80 degrees Celsius. Contraindications to procurement comprised history of infection and malignancy, all clinics tested donors for HIV antibodies and all but one for hepatitis B. Testing for hepatitis C was about to be introduced. All but one clinic developed cultures from the procured bone. Informed consent was employed by nearly all clinics, but very few obtained written consent. Since this survey, revised recommendations have been directed from the Danish National Board of Health, these listing that an HIV-test should be performed with a 90-day interval, and that testing should also be done for hepatitis B and C. International experience and this survey show that the establishment of more specific and general national recommendations would be preferable to present practice.

Effect of adjuvant formulations on the induction of virus-neutralizing and virus-binding antibodies by chemosynthetic peptides of VP1 of foot-and-mouth-disease virus

Synthetic peptides corresponding to the 141-160 amino acid sequence of the protein VP1 of virus type O1 Kaufbeuren (O1K) and A5 Riems (A5R) were conjugated to thyroglobulin and mixed with complete Freund's adjuvant (CFA) or incomplete Freund's adjuvant (IFA) together with Quil A. Although the peptide of A5R, together with IFA and Quil A, or with CFA, elicited a high antibody response to the virus in the ELISA, formula containing both IFA and Quil A induced only high titres of virus-neutralizing antibodies in rabbits. These adjuvant formulas did not display significant differences with regard to side effects.