An abattoir survey of pneumonia and pleuritis in slaughter weight swine from 9 selected herds. IV. Bacteriological findings in chronic pneumonic lesions

A total of 855 pig lungs were collected at slaughter and evaluated macroscopically. Bacteriological examinations were carried out on tissue samples from chronic pleuropneumonic lesions (n = 196) and from chronic bronchopneumonic lesions with suppuration (n = 14). Samples from normal lung tissue (n = 22) were also included. Pasteurella multocida was isolated from 54%, Actinobacillus (Haemophilus) pleuropneumoniae from 11%, and Streptococcus spp. from 14% of the pneumonic lesions, respectively. From normal lung tissue P. multocida was isolated from 3 (14%) of the samples, A. pleuropneumoniae was not recovered and streptococci were isolated from only 1 (5%) of these samples. The above mentioned bacterial species were recovered either in pure cultures or mixed with various other microbes. A total of 109 P. multocida strains were further characterized by capsular serotyping and testing for production of dermonecrotic toxin. Ninety-nine (91%) of the strains were capsular type A 10 (9%) were type D. Out of the type A and the type D strains 94% and 90% were toxigenic, respectively. Most of the A. pleuropneumoniae strains were serotype 2. Strains of serotypes 1 and 7 were also identified. The majority of the streptococci were identified as either Streptococcus suis or Streptococcus dysgalactiae. Actinomyces pyogenes was isolated from 14% of the lesions and anaerobic bacteria from 18%, respectively. The significance of the various bacterial species in relation to the development of chronic pneumonic lesions is discussed. Special attention is paid to P. multocida, and it is concluded that this bacterial species is probably of importance for the development of both types of chronic pneumonias.

An abattoir survey of pneumonia and pleuritis in slaughter weight swine from 9 selected herds. I. Prevalence and morphological description of gross lung lesions

The prevalence and pathomorphology of gross lung lesions were studied in 855 slaughter weight pigs from 9 selected herds in south-eastern Norway. Pneumonic or pleuritic lesions were found in 84% of the lungs, ranging from 37% in the least affected herd to 97% in the one most affected. Bronchopneumonia indicative of a primary Mycoplasma hyopneumoniae infection was found in 70% of the lungs, ranging from 9% to 82% in the individual herds. The amount of bronchopneumonic lesions in individual lungs ranged from 0 to 69%, with an average of 7.8%. Pleuropneumonia indicative of Actinobacillus (Haemophilus) pleuropneumoniae infection was found in 29% of the lungs ranging from 0 in the least affected herd to 58% in the most affected. Diffuse pleuritis was found in 41% of the lungs and the prevalence ranged from 4% to 63%.

An abattoir survey of pneumonia and pleuritis in slaughter weight swine from 9 selected herds. III. Serological findings and their relationship to pathomorphological and microbiological findings

Blood samples from 777 pigs, originating from 9 different herds, were collected at slaughter and examined for antibodies to Mycoplasma hyopneumoniae and Actinobacillus (Haemophilus) pleuropneumoniae by the indirect hemagglutination assay (IHA) and the complement fixation (CF) test, respectively. Results were compared to pathological and microbiological findings. Antibodies to M. hyopneumoniae in positive titers of 1/80 or higher were found in 62% of the samples. The relationship between positive IHA titers to M. hyopneumoniae and gross findings indicative of enzootic pneumonia of pigs (EPP), histological findings indicative of EPP, the isolation of M. hyopneumoniae and the demonstration of M. hyopneumoniae by indirect immunofluorescent testing ranged from 64% to 68%. No correlation was noted between positive IHA titers and the isolation of Mycoplasma flocculare. Positive antibody titers to A. pleuropneumoniae of 1/10 or higher were detected in 5% to 85% of the samples from individual herds. Positive titers to A. pleuropneumoniae serotype 2 were found in 71% to 79% of the sampled animals from herds with high frequencies of pneumonic lesions indicative of pleuropneumonia. In herds with low frequencies of pleuropneumonia, positive titers were recorded in from 0 to 4% of the tested pigs. However, no statistical association was found between pleuropneumonia and positive titers to A. pleuropneumoniae serotype 2 in individual animals. Twenty-one per cent of samples with positive CF titers to A. pleuropneumoniae showed antibodies to more than one serotype.

An abattoir survey of pneumonia and pleuritis in slaughter weight swine from 9 selected herds. II. Enzootic pneumonia of pigs: microbiological findings and their relationship to pathomorphology

Lungs from 191 slaughter pigs with gross lesions indicative of enzootic pneumonia of pigs (EPP) and 80 grossly normal lungs, all originating from 9 different herds, were subjected to microbiological and pathological examinations. The microbiological studies included both bacterial and mycoplasmal culture and also testing for Mycoplasma hyopneumoniae antigen in tissue by indirect immunofluorescent technique. M. hyopneumoniae, Pasteurella multocida and Mycoplasma hyorhinis were detected in 83%, 43% and 37% of the pneumonic lungs, respectively. Mycoplasma flocculare was the most frequently isolated organism in the non-pneumonic lungs. The greatest amounts of macroscopic pneumonia (25.2%) were recorded in lungs with all the three agents M. hyopneumoniae, P. multocida and M. hyorhinis present. The amounts of pneumonia in lungs with M. hyopneumoniae alone and in concurrence with P. multocida, were 9.3% and 15.6%, respectively. M. hyorhinis was also, in this study, associated with higher frequency of diffuse pleuritis. These findings indicate that M. hyorhinis might be involved in the pathogenesis of pneumonia in slaughter pigs. Ninety-six per cent of the isolates of P. multocida from pneumonic lungs could be characterized as type A. In the herds which had the most severe pneumonia problems, toxin production was detected in 83% of the P. multocida strains while only 28% were toxigenic in herds with subclinical to moderate pneumonia problems.

Expression of Epstein-Barr virus-encoded proteins and B-cell markers in fatal infectious mononucleosis

We assessed 33 lymphoid tissues from 15 patients, including 7 with X-linked lymphoproliferative disease (XLP) and 8 patients with sporadic fatal infectious mononucleosis (IM), to determine whether the cellular infiltrate had the immunophenotype and expressed Epstein-Barr virus (EBV)-encoded proteins characteristic of either EBV-immortalized lymphoblastoid cell lines (LCL) or EBV-carrying Burkitt lymphoma (BL) cells. The results of these studies revealed that in 13 cases the proliferating B cells were polyclonal, LCL-like, and in 2 cases they were monoclonal, malignant lymphoma-like.

Isolation and analysis of naturally processed viral peptides as recognized by cytotoxic T cells

Virus-infected cells can be eliminated by cytotoxic T lymphocytes (CTL), which recognize virus-derived peptides bound to major histocompatibility complex (MHC) class I molecules on the cell surface. Until now, this notion has relied on overwhelming but indirect evidence, as the existence of naturally processed viral peptides has not been previously reported. Here we show that such peptides can be extracted from virus-infected cells by acid elution. Both the naturally processed H-2-Db-restricted and H-2-Kd-restricted peptides from influenza nucleoprotein are smaller than the corresponding synthetic peptides, which have first been used to determine the respective CTL epitopes. As with minor histocompatibility antigens, occurrence of viral peptides seems to be heavily dependent on MHC class I molecules, because infected H-2d cells do not contain the H-2-Db-restricted peptide, and infected H-2b cells do not contain the H-2-Kd-restricted peptide. Our data provide direct experimental proof for the above notion on MHC-associated viral peptides on virus-infected cells.

Cellular peptide composition governed by major histocompatibility complex class I molecules

Major histocompatibility complex (MHC) class I molecules present peptides derived from cellular proteins to cytotoxic T lymphocytes (CTLs), which check these peptides for abnormal features. How such peptides arise in the cell is not known. Here we show that the MHC molecules themselves are substantially involved in determining which peptides occur intracellularly: normal mouse spleen cells identical at all genes but MHC class I express different patterns of peptides derived from cellular non-MHC proteins. We suggest several models to explain this influence of MHC class I molecules on cellular peptide composition.

Characterization of naturally occurring minor histocompatibility peptides including H-4 and H-Y

Minor histocompatibility (H) antigens can be peptides derived from cellular proteins that are presented on the cell surface by major histocompatibility complex (MHC) class I molecules. This is similar to viral antigens, because in both cases cytotoxic T lymphocytes (CTLs) recognize artificially produced peptides loaded on target cells. Naturally processed minor H peptides were found to be similar to those artificial CTL-epitopes, as far as size and hydrophobicity is concerned. The peptides studied were isolated from a transfectant that expressed a model CTL-defined antigen, beta-galactosidase, from male cells that express H-Y, which has been known operationally since 1955, and from cells that express H-4, known since 1961.

The role of methylation in the phenotype-dependent modulation of Epstein-Barr nuclear antigen 2 and latent membrane protein genes in cells latently infected with Epstein-Barr virus

Seven virus-encoded proteins are regularly expressed in Epstein-Barr virus (EBV)-transformed lymphoblastoid (LCL) cell lines: the EBV nuclear antigens EBNA 1 to 6 and the latent membrane protein (LMP). In nasopharyngeal carcinoma (NPC), only EBNA 1 is regularly expressed; LMP is detected in about 50% of the tumours. In Burkitt's lymphoma (BL) tumours, only EBNA 1 is expressed. Also, in BL-derived cell lines that maintain the phenotypic markers characteristic of the in vivo tumour (group I), only EBNA 1 is expressed. EBV was rescued by induction or cocultivation from one BL cell line with a restricted group I pattern, and from one NPC tumour, into normal B cells. In the resulting LCLs EBNA 1 to 6 and LMP were expressed. We assessed the level of methylation in the genes encoding ENBNA 2 and LMP by restriction fragment analysis using the methylation-sensitive enzymes SmaI and HpaII. These genes were extensively methylated in the group I BL line Rael and the nude mouse-passaged C15 NPC tumour, but were demethylated in the derived LCLs. In the LMP-expressing NPC C15 tumour the 5' flanking region of the gene was hypomethylated, whereas the coding exons were methylated [corrected]. The EBNA 1 coding exon was methylated in the Rael line and in NPC, in spite of expression. In contrast, CpG pairs in oriP were originally hypomethylated and remained so after their transfer to LCLs. The cell phenotype-dependent pattern of EBV gene methylation correlated with the phenotype-dependent pattern of EBNA and LMP expression. The specific patterns of methylation localized to controlling regions (oriP and 5' flanking sequences) also suggest a specific role for methylation in the regulation of EBNA and LMP expression.

5-Azacytidine up regulates the expression of Epstein-Barr virus nuclear antigen 2 (EBNA-2) through EBNA-6 and latent membrane protein in the Burkitt's lymphoma line rael

Nonproductive infection of B lymphocytes by Epstein-Barr virus (EBV) is associated with a highly restricted expression of viral genes. In growth-transformed lymphoblastoid cell lines, the products of these genes include a complex of at least six EBV nuclear antigens (EBNAs) (EBNA-1 through EBNA-6) and one membrane protein (latent membrane protein [LMP]). EBV-carrying Burkitt's lymphoma (BL) biopsies and derived cell lines that have retained a representative phenotype (group I BL lines) express only EBNA-1 (M. Rowe, D. T. Rowe, C. D. Gregory, L. S. Young, P. J. Farrell, H. Rupani, and A. B. Rickinson, EMBO J. 6:2743-2751, 1987). We have found that EBNA-2 through EBNA-6 and LMP can be up regulated by treating the group I BL line Rael with the DNA-demethylating agent 5-azacytidine (5-AzaC). The drug acted in a time- and dose-dependent manner. EBNA-2-positive cells were detected by anti-complement immunofluorescence staining just 12 h after addition of 4 microM 5-AzaC and reached a maximum number at 72 h, when up to 75% of the population was positive. EBNA-2, EBNA-3, EBNA-4, EBNA-4, EBNA-6, and LMP were demonstrated immunoblots starting at 48 h. The EBV-encoded early antigens and viral capsid antigens were also induced but at a lower level. EBNA-2 and the lytic cycle-associated antigens appeared with a different time course and in largely nonoverlapping cell subpopulations, as demonstrated by double fluorescence staining. Thus, EBNA-2 expression was not restricted to lytically infected cells, nor was EBNA-2 required for entry into the lytic cycle. The coding and regulatory sequences of EBNA-2 and LMP were found to be highly methylated in Rael cells and were, as expected, demethylated after 5-AzaC treatment. These findings suggest that DNA methylation may participate in the regulation of growth transformation-associated viral genes in BL cells.

[Difficult intubation and anesthesia in Pfaundler-Hurler disease]

Because of increasing dyspnea, adenoidectomy and tonsillectomy were indicated in a 6-year-old girl with Pfaundler-Hurler disease. The main symptoms were cardiac insufficiency and chronic bronchitis. Because of the large skull with hypoplastic cervical spine, anomalies of facial bones, larynx and jawbone normal intubation was impossible. We therefore performed intubation during spontaneous breathing under inhalation anesthesia and topical anesthesia of the larynx. After exploratory laryngoscopy a preformed Woodbridge tube was inserted into the trachea blind and by ear during of inspiration. The patient's cardiac insufficiency and chronic bronchitis made a balanced anesthesia with reduced dosage of rapifen and halothane necessary. In spite of the poor general prognosis, after the operation a considerable relief of the patient's suffering was noted, because she was able to breathe freely.

Expression of Epstein-Barr virus-encoded proteins in nasopharyngeal carcinoma

Expression of the Epstein-Barr virus (EBV) encoded nuclear antigens (EBNA 1 to 6) and membrane-associated protein (LMP) was investigated by immunoblotting in 83 nasopharyngeal carcinoma (NPC) biopsies and 25 other tumor and normal tissue specimens from the head and neck region. Fifty-eight of the 83 NPC biopsies were large enough to yield parallel data on virus DNA and viral expression. All 16 cases of clinically diagnosed and histologically confirmed NPCs from North Africa contained EBV DNA and expressed EBNA-1. Of 31 clinically diagnosed NPCs from China, 29 contained EBV DNA and 25 of these expressed EBNA-1. One control tissue biopsy from the oropharynx of NPC patients contained EBV DNA, but none expressed EBNA-1. The latent membrane protein (LMP) was detected in 22/31 of the Chinese and in 10/16 of the North African NPC biopsies. None of the NPC biopsies or control tissues expressed detectable amounts of EBNA 2 or any of the other 4 nuclear antigens which are invariably expressed in EBV-transformed B cells. A smaller number of tumors from Malaysia and East Africa exhibited a similar pattern of expression. EBV was rescued from a nude-mouse-passaged North African NPC tumor by co-cultivation of the tumor cells with umbilical cord blood lymphocytes. The tumor expressed EBNA 1 and LMP, but not EBNA 2 or the other 4 EBNAs. The resulting LCLs expressed all 6 nuclear antigens, EBNA 1 to 6 and LMP. Our data suggest that expression of the EBV genome is regulated in a tissue-specific fashion.

The effect of trauma to the leg on the first-pass uptake of bacteria by the lung

Our previous studies have shown that the first-pass pulmonary uptake of lidocaine and serotonin were not impaired by bullet wounding of the leg. Since there is decreased resistance to bacterial infection with trauma, it was of interest to study the uptake of bacteria. First-pass pulmonary uptake of 51-chromium-labeled, killed Salmonella typhimurium bacteria was studied in 26 pigs. In 16 controls, four injections at hourly intervals revealed an initial uptake of 84.5% +/- 1.5 (Mean +/- S.E.M.) and a 95% first-pass uptake of 78.6% +/- 2.4, and no significant change with time. In the ten traumatized animals only the values at 5 hours were significantly lower than the controls. It is concluded that repeated injections of killed Salmonella typhimurium bacteria without trauma do not interfere with the ability of the lung to remove these bacteria during their first passage through the lung, but that with trauma to the leg do to a slight degree.

Progenitor and pre-B lymphocytes transformed by Epstein-Barr virus

By rosetting with SRBC coupled to rabbit-anti-human IgM, the surface IgM-negative cells of human fetal bone marrow were enriched, and subsequently infected and transformed by Epstein-Barr virus (EBV). Single clones of the transformed cells were obtained. Ninety percent of the resulting cell clones were surface-immunoglobulin-negative, and of 8 clones which were further studied, 5 lacked intracellular, cytoplasmic Ig as measured by immunofluorescence. Control cell clones derived from the same material without pre-selection expressed surface Ig and also secreted Ig. Utilization of a panel of B-cell-specific monoclonal antibodies (MAbs) showed no difference between the cell clones expressing surface Ig and those that did not. The progenitor B-cell lines did not show a phenotype resembling that of cell lines derived from B-cell malignancies, such as high agarose clonability. In spite of their immature Ig-phenotype, these clones showed rearrangement of at least one heavy chain Ig-allele. Efforts to induce differentiation in these clones were unsuccessful. These clones may represent progenitor B cells, or B cells with faulty heavy-chain rearrangement. EBV can apparently be used as a tool to derive cell lines representing different levels of B-cell differentiation, and can also transform immature B cells, which may be useful in the analysis of B-cell differentiation.

Lymphoblastoid cell lines and Burkitt-lymphoma-derived cell lines differ in the expression of a second Epstein-Barr virus encoded nuclear antigen

Twenty-seven Epstein-Barr virus (EBV)-transformed lymphoblastoid cell lines and 27 EBV-carrying Burkitt-lymphoma-derived lines were analyzed for expression of the second EBV-encoded nuclear antigen (EBNA-2) by immunoblotting and anticomplement immunofluorescence with EBNA-2-specific sera. While all lymphoblastoid cell lines expressed EBNA-2, only 10 of the 27 BL lines were EBNA-2-positive. Comparison of the EBNA-2 coding BamHI W-, Y- and H-fragments of EBV-DNA in the different cell lines by restriction enzyme analysis suggests that EBNA-2 negativity is due either to sequence diversity or to a deletion in the BamHI WYH region.

Epstein-Barr virus transformation of human pre-B cells

In vitro infection of human B lymphocytes with Epstein-Barr virus (EBV) results in establishment of B lymphoblastoid cell lines that reflect normal B cell phenotypes. In this study we have investigated whether immature B cells from fetal bone marrow and liver can serve as targets for EBV. The fetal bone marrow cells were readily transformed by EBV. Among the resulting cell lines, five were surface Ig (sIg)-negative. Three B cell-associated antigens defined by monoclonal antibodies were expressed to the same extent on the fetal cell lines, whether they belonged to the sIg- or sIg+ group. The various differentiation stages that these cell lines may represent are discussed.