Fine mapping of bovine herpesvirus-1 (BHV-1) glycoprotein D (gD) neutralizing epitopes by type-specific monoclonal antibodies and sequence comparison with BHV-5 gD

Overlapping fragments of the bovine herpesvirus-1 (BHV-1) glycoprotein (gD) ORF were expressed as trpE-gD fusion proteins in Escherichia coli to map linear neutralizing epitopes defined by BHV-1-specific MAbs. The MAbs 3402 and R54 reacted with the expressed fragments on Western blots that located the epitopes between the amino acids 52-126 and 165-216, respectively, of gD. Bovine covalescent sera with high neutralizing antibody titers against BHV-1 reacted with these bacterially expressed proteins containing both of the epitopes. Alignment of these sequences from BHV-1 with the corresponding region of the BHV-5 gD ORF sequences (reported here) identified several amino acid mismatches. Since the MAbs 3402 and R54 neutralize the BHV-1 and not BHV-5, it was presumed that these were important amino acids in defining the epitope. To further localize the neutralizing epitopes, synthetic peptides corresponding to these regions in the BHV-1 gD ORF were tested for their capacity to block monoclonal antibody neutralization of BHV-1 infectivity. The peptides encompassing amino acids 92-106 (3402 epitope) and amino acids 202-213 (R54 epitope) of the BHV-1 gD competed with BHV-1 for the binding by MAbs 3402 and R54, respectively, in a dose-dependent manner. Antisera produced in rabbits to these peptides conjugated to a carrier reacted strongly with a 30-kDa protein by Western blotting and had neutralizing antibody titers against BHV-1.

Epitope-specific antibody responses in market-stressed calves to bovine herpesvirus type 1

Reciprocal competition ELISA (rcELISA) was conducted to map monoclonal antibodies (mAbs) reactive with gI, gIII and gIV glycoproteins of bovine herpesvirus type 1 (BHV-1) into epitope groups. mAbs to glycoproteins gI and gIV were divided into six epitope groups each, while gIII mAbs had been previously divided into four areas. mAbs were chosen from each epitope group to compete in cELISA wih bovine sera collected during a typical regimen of vaccination and transportation from farm to auction to feedlot. The immunodominant epitopes were identified for each BHV-1 glycoprotein. With glycoprotein gI, three epitopes defined by mAbs 1F10, D9 and 4807 were the most dominant; with glycoprotein gIII epitopes defined by mAbs G2 and 1507, and with glycoprotein gIV epitopes defined by mAbs 1102, 1106, 3C1, 3402 and 3E7 showed the maximum responses. The overall cELISA responses to each glycoprotein among two vaccination groups were also compared and it was shown that cELISA responses were significantly higher for each glycoprotein in calves receiving two vaccinations, one on the farm of origin and one at auction, than in calves receiving only one vaccination at auction.

Experimental infection of neonatal calves with neurovirulent bovine herpesvirus type 1.3

A type of bovine herpesvirus, BHV-1.3, causes encephalitis in calves, whereas BHV-1.1 causes respiratory disease. Three colostrum-deprived calves and two colostrum-fed calves were inoculated with BHV-1.3 by intranasal aerosolization. Two colostrum-deprived calves were inoculated with BHV-1.1 by intranasal aerosolization. BHV-1.3-inoculated calves demonstrated severe encephalitis with minimal respiratory lesions, and BHV-1.1-inoculated calves demonstrated severe respiratory lesions and no clinical signs of neurologic disease. Calves fed colostrum that contained virus neutralizing antibodies were protected against neurologic disease. Colostrum-fed BHV-1.3-inoculated calves did not develop disease although they did become infected; virus was shed in respiratory secretions for 10-13 days postinoculation, similar to infected colostrum-deprived calves. BHV-1.3 was reactivated from a latent state from one colostrum-fed calf after administration of dexamethasone 60 days postinoculation. Histopathologic examination of the three colostrum-deprived BHV-1.3-inoculated calves revealed severe lesions of encephalitis. One of the two BHV-1.1-inoculated calves had one focal lesion of encephalitis. Virus was isolated from brain tissue of colostrum-deprived BHV-1.3-inoculated calves and from one BHV-1.1-inoculated calf. Immunohistochemical staining for BHV-1 antigen was observed in neurons from the colostrum-deprived BHV-1.3-inoculated calves.

Monoclonal antibodies that distinguish between encephalitogenic bovine herpesvirus type 1.3 and respiratory bovine herpesvirus type 1.1

Seven mouse hybridoma cell lines producing monoclonal antibodies (MAb) against an encephalitogenic strain of bovine herpesvirus type 1.3 (BHV-1.3) were established. The clones producing MAb were selected to be specific for BHV-1.3 by enzyme-linked immunosorbent assay. Only L1B neutralized virus without complement. With the addition of complement, five of the MAb neutralized BHV-1.3 but not the respiratory strain BHV-1.1. The anti-BHV-1.3-specific MAb Q10B, L6G, and L1B precipitated glycoproteins from BHV-1.3 that were analogous to the gI, GIII, and gIV glycoproteins of BHV-1.1, respectively. The other four MAb precipitated unknown proteins. None of the anti-BHV-1.3 MAb precipitated BHV-1.1 glycoproteins. The majority of the anti-BHV-1.3 MAb did not react with BHV-1.1 by immunoblotting, but O7E (unknown protein pattern by radioimmunoprecipitation) was reactive with five proteins (M(r)s of 33,000, 43,000, 70,000, 141,000, and 190,000) of BHV-1.3 and with a different pattern of proteins of BHV-1.1 (M(r)s of 30,000, 38,000, 83,000 and 144,000). Two of the MAb, L6G and O7E, conjugated with peroxidase were found to be useful for detecting BHV-1.3 antigen by immunochemistry in Formalin-fixed brain tissue from experimentally infected calves.

An immune suppressive factor derived from esophageal squamous carcinoma induces apoptosis in normal and transformed cells of lymphoid lineage

An immunosuppressive factor produced by an esophageal squamous carcinoma cell line mediates profound irreversible suppression of in vitro proliferative responses of lymphoid cells. Exposure of activated normal PBL to the immune suppressive factor (ISF) resulted in the induction of an irreversible anergic state with apoptosis evident in 20% of those cells. Flow cytometric cell cycle analysis of mitogenically stimulated normal lymphocytes exposed to the ISF revealed that despite exhibiting full activation status (IL-2 production, IL-2R, and transferrin receptor expression) PBL were arrested at the G1/S interphase of the cell cycle. Transformed lymphoid cell lines, NSO and JURKAT, displayed morphologies characteristic of apoptosis within 24 h of exposure to the ISF. Flow cytometric cell cycle analysis of the JURKAT cells incubated with ISF revealed that > 90% of these cells had undergone apoptosis within 24 h. Agarose gel electrophoresis of DNA extracted from the ISF-treated lymphoid cells resolved a DNA fragmentation pattern characteristic of apoptosis in both the NSO cells and to a lesser extent in the activated PBL exposed to the ISF but not in control cells. In JURKAT cells stimulated with anti-CD3 antibodies, Ca2+ mobilization was markedly enhanced in those cells exposed to ISF. Also, ISF independently induced a calcium flux in JURKAT cells. Induction of programmed cell death by ISF may account for the in vivo immune suppression local to the tumor site in squamous carcinoma of the esophagus.

An immune suppressive factor derived from esophageal squamous carcinoma induces apoptosis in normal and transformed cells of lymphoid lineage

An immunosuppressive factor produced by an esophageal squamous carcinoma cell line mediates profound irreversible suppression of in vitro proliferative responses of lymphoid cells. Exposure of activated normal PBL to the immune suppressive factor (ISF) resulted in the induction of an irreversible anergic state with apoptosis evident in 20% of those cells. Flow cytometric cell cycle analysis of mitogenically stimulated normal lymphocytes exposed to the ISF revealed that despite exhibiting full activation status (IL-2 production, IL-2R, and transferrin receptor expression) PBL were arrested at the G1/S interphase of the cell cycle. Transformed lymphoid cell lines, NSO and JURKAT, displayed morphologies characteristic of apoptosis within 24 h of exposure to the ISF. Flow cytometric cell cycle analysis of the JURKAT cells incubated with ISF revealed that > 90% of these cells had undergone apoptosis within 24 h. Agarose gel electrophoresis of DNA extracted from the ISF-treated lymphoid cells resolved a DNA fragmentation pattern characteristic of apoptosis in both the NSO cells and to a lesser extent in the activated PBL exposed to the ISF but not in control cells. In JURKAT cells stimulated with anti-CD3 antibodies, Ca2+ mobilization was markedly enhanced in those cells exposed to ISF. Also, ISF independently induced a calcium flux in JURKAT cells. Induction of programmed cell death by ISF may account for the in vivo immune suppression local to the tumor site in squamous carcinoma of the esophagus.

Antigenic differences between the major glycoproteins of bovine herpesvirus type 1.1 and bovine encephalitis herpesvirus type 1.3

Differences in the antigenic structure of the major glycoproteins, gI, gIII and gIV, of bovine herpesvirus type 1.1 (BHV1.1) and the neurovirulent BHV1.3 were demonstrated with a panel of monoclonal antibodies (MAbs) prepared against the BHV1.1 glycoproteins. Glycoprotein gIII of BHV1.3 was the most dissimilar, reacting with only four of 15 gIII-specific MAbs. Glycoproteins gI and gIV of BHV1.3 reacted with eight of 11 and eight of 12 specific MAbs, respectively. Monospecific bovine antisera to the two viruses supported findings from the MAb analysis in that gI and gIV glycoproteins were cross-recognized, but gIII was not. Virus-neutralizing MAbs reactive to each glycoprotein and which reacted with both viruses also neutralized both viruses. Previously undescribed glycoproteins which were antigenically related to the intact gIII glycoproteins, but of reduced sizes and lacking at least one gIII epitope, were found for both viruses. Tunicamycin inhibition experiments and immunoprecipitation data suggested that these proteins were intracellular degradation products. Comparisons of the peptide footprints of the glycoproteins from the two viruses using protease V8 digestion after immunoprecipitation with cross-reactive MAbs revealed distinctive footprint patterns for the respective glycoproteins.

Use of an immunoperoxidase technique to detect equine herpesvirus-1 antigen in formalin-fixed paraffin-embedded equine fetal tissues

An indirect immunoperoxidase (IP) procedure using the avidin-biotin-peroxidase complex detection technique was developed to detect viral equine herpesvirus-1 (EHV-1) antigen in formalin-fixed paraffin-embedded tissues from aborted equine fetuses. The procedure was applied to liver, lung, and other tissues from 20 cases of confirmed or suspected EHV-1-induced abortions. Specific staining was observed in tissue sections from EHV-1-infected fetuses. Positive IP staining was present in tissues of 7 cases that were also positive by fluorescent antibody (FA) and virus isolation (VI) and that had typical histologic lesions. There was no IP staining in 7 cases that had no histologic lesions and negative FA and VI results. Five cases had typical histologic lesions and positive results in only 1 laboratory test; 3 were positive by VI and 2 by FA. Liver of 1 case was positive by IP, but tissues were too autolytic for other tests to be evaluated.

Future challenges for behavioural research in adolescent health

Risk to health during adolescence is more likely due to behaviour than disease. Problems arise because behaviour is distally removed from its consequences and negative reinforcement is not contiguous with it. The paper reviews recent research and the problems faced by health workers in devising educational programmes when behaviour, in the cultural value system of adolescents, is present-oriented and outcomes are future-oriented. The challenge to the behavioural scientist is to develop health education programmes which have personal meaning to adolescents. Working against this aim are such processes as adolescent taboos, locus of control, the personal fable, risk behaviours and social-cognitive immaturity. Suggestions are made for research scientists to devise and evaluate programmes to change the operational liberalism of adolescent behaviour by installing more ideologically conservative attitudes in the hope that behavioural change will follow.

Serologic prevalence of selected infectious diseases in cats with uveitis

Serologic evidence of infection by Toxoplasma gondii, feline leukemia virus, feline coronaviruses, or feline immunodeficiency virus (FIV) is commonly found in cats with uveitis. Serum samples from 124 cats with uveitis were assayed by use of ELISA for the detection of T gondii-specific immunoglobulin M (IgM), IgG, and circulating antigens (Ag), as well as an ELISA for feline leukemia virus Ag, an ELISA for antibodies to FIV, and an indirect fluorescent antibody assay for antibodies to feline coronaviruses. Serologic evidence of infection by 1 or more of the infectious agents was detected in 83.1% of the samples. Serologic evidence of T gondii infection, defined as the detection of T gondii-specific IgM, IgG, or Ag in serum, was found in 74.2% of the samples. The seroprevalence of T gondii infection was significantly greater in cats with uveitis than in healthy cats from a similar geographic area. Serum samples from cats with serologic evidence of both T gondii and FIV infections were more likely to contain T gondii-specific IgM without IgG than samples from cats with serologic evidence of T gondii infection alone. Cats with serologic evidence of FIV and T gondii coinfection had a higher T gondii-specific IgM titer geometric mean and a lower T gondii-specific IgG titer geometric mean than did cats with serologic evidence of T gondii infection alone. Serologic evaluation for T gondii infection should include assays that detect IgM, IgG, and Ag, particularly in cats coinfected with FIV.

Abomasal erosions in feedlot cattle

The abomasa of 1,949 slaughtered feedlot cattle, 45 necropsied feedlot cattle that died 2 to 45 days after arrival, and 45 necropsied pastured cattle were opened and examined. Of these organs, 484, 1, and none, respectively, contained erosions. The slaughtered cattle were fattened at 3 locations: 1,305 with 430 eroded abomasa were fed a ration of corn in northeastern Colorado; 144 cattle with 4 affected abomasa fed a ration of milo in south-central Arizona; and 500 cattle with 50 affected abomasa fed a ration of milo and corn in northwestern Texas. The red-brown lesions developed late during the second semester of fattening and were located mostly on fundic folds. Those on fold edges were linear and were 2 to 15 cm long, whereas those on fold sides were punctate and were 2 to 15 mm in diameter. Normal fold edges contained fewer goblet cells and less surface mucus than did fold sides. Eroded folds had disruption of surface epithelium, damage to endothelial cells, and dilated, thrombosed, congested, and ruptured capillaries. Mean pH values of 16 normal and 17 eroded abomasa were 4.7 and 3.9, respectively. Necrosis of all tissue toward the mucosal surface of erosions was extensive. The cause of gastric erosion in cattle is not known.

The neurology of endemic cretinism. A study of two endemias

Endemic cretinism is the most severe manifestation of dietary iodine deficiency. Two forms of the syndrome are traditionally described: neurological and myxoedematous. Although this classification highlights the important neurological sequelae of the disorder it implies that myxoedematous cretins have an alternative mechanism. Further, the nature of the neurological deficit associated with both types of endemic cretinism has received scant attention in recent times considering that it remains a common disorder in many parts of the world. The nature and extent of the neurological deficit found in endemic cretinism was investigated in 104 cretins from a predominantly myxoedematous endemia in western China and in 35 cretins from central Java, Indonesia, a predominantly neurological endemia. We found a similar pattern of neurological involvement in nearly all cretins from both endemias, regardless of type (myxoedematous or neurological), and of current thyroid function. Hallmarks of the neurological features included mental retardation, pyramidal signs in a proximal distribution and extrapyramidal signs. Many patients exhibited a characteristic gait. This probably reflected pyramidal and extrapyramidal dysfunction, although joint laxity and deformity were important contributing factors. Other frequently encountered clinical features were squint, deafness, and primitive reflexes. Cerebral computerized tomography (CT) revealed basal ganglia calcification in 15 of 50 subjects. The presence of basal ganglia calcification was confined to cretins with severe hypothyroidism. Otherwise, cerebral CT scanning demonstrated only minor abnormalities which did not contribute to the localization of the clinical deficits. We conclude that the same neurological disorder is present in both types of endemic cretinism reflecting a diffuse insult to the developing fetal nervous system. These clinical findings support the concept of maternal and fetal hypothyroxinaemia, arising from severe iodine deficiency, as the primary pathophysiological event in endemic cretinism. Differences between the two types of cretinism may be explained by continuing postnatal thyroid hormone deficiency in the myxoedematous type, which results in impaired growth, skeletal retardation and sexual immaturity.

Detection of cattle infected with bovine viral diarrhea virus using nucleic acid hybridization

A ribonucleic acid (RNA) hybridization assay to identify cattle infected by bovine viral diarrhea virus (BVDV) is described. The RNA probe was derived from the coding region at the 3' end of the genome of the NADL strain of BVDV. Total RNA from infected cell cultures or peripheral blood leukocytes from suspect animals was extracted and applied to nylon membranes with a slot blot apparatus. Peripheral blood leukocytes were tested concurrently for BVDV by virus isolation. The results of hybridization and virus isolation were in agreement for 92% of the cases. When compared with virus isolation, hybridization had a sensitivity of detection of 59.5% and a specificity of 95%. Cross-reactivity to RNA extracts of border disease virus-infected cells was noted. No cross-reactivity was detected to other common bovine viruses (bovine herpesvirus-1, bovine respiratory syncytial virus, parainfluenza-3 virus, and bluetongue virus), to viruses classified in related families (equine arteritis virus and Venezuelan equine encephalitis virus), or to viruses having similar genomic organization (dengue virus type 2 and Japanese encephalitis virus).

Eperythrozoon wenyonii infection in dairy cattle

Approximately 10 of 100 young heifers that had recently delivered their first calf--members of a large Colorado dairy herd--had a syndrome of swollen teats and distal portions of the hind limbs, prefemoral lymphadenopathy, transient fever, rough coat, decreased milk production, and subsequent weight loss and reproductive inefficiency. Acute clinical signs of disease were associated with large numbers of Eperythrozoon wenyonii seen on blood smears, and resolution of signs correlated with reduction or disappearance of the parasite. Other known causes of peripheral edema could not be documented. The parasite was transmitted to 4 of 7 nonlactating dairy cows destined to be culled and a splenectomized calf via IV inoculation of blood from parasitemic heifers, but clinical signs of infection were not induced.

Tissue distribution of a coliphage and Escherichia coli in mussels after contamination and depuration

Experiments were undertaken to determine the tissue distribution of Escherichia coli and a coliphage after contamination of the common mussel (Mytilus edulis). Mussels were contaminated with high levels of feces-associated E. coli and a 22-nm icosahedral coliphage over a 2-day period in a flowing-seawater facility. After contamination, individual tissues were carefully dissected and assayed for E. coli and the coliphage. Contaminated mussels were also analyzed to determine the tissue distribution of the contaminants after 24- and 48-h depuration periods. The majority of each contaminant was located in the digestive tract (94 and 89% of E. coli and coliphage, respectively). Decreasing concentrations were found in the gills and labial palps, foot and muscles, mantle lobes, and hemolymph. Our results indicate that contamination above levels in water occurred only in the digestive tract. Contaminated mussels were depurated in a commercial-scale recirculating UV depuration system over a 48-h period. The percent reductions of E. coli occurred in the following order: digestive tract, hemolymph, foot and muscles, mantle lobes, and gills and labial palps. The percent reductions of the coliphage were different, occurring in the following order: hemolymph, foot and muscles, gills and labial palps, mantle lobes, and digestive tract. Our results clearly demonstrate that E. coli and the coliphage are differentially eliminated from the digestive tract. The two microorganisms are eliminated at similar rates from the remaining tissues. Our results also clearly show that the most significant coliphage retention after depuration for 48 h is in the digestive tract. Thus, conventional depuration practices are inappropriate for efficient virus elimination from mussels.

Use of in situ hybridization with a biotinylated probe for the detection of bovine herpesvirus-1 in aborted fetal tissue

Forty-five cases of bovine abortion were examined using in situ hybridization (ISH) with a biotinylated DNA probe specific for bovine herpesvirus-1 (BHV-1). Of the 45 cases, 16 were diagnosed as due to BHV-1, 15 were determined to be due to other causes, and 14 were of undetermined etiology. Direct comparisons between ISH and an immunoperoxidase (IP) test specific for BHV-1 were performed on formalin-fixed, paraffin-embedded tissue sections of lung, liver, kidney, spleen, thymus, and placenta; fluorescent antibody tests for BHV-1 and virus isolation were performed on fresh lung and liver. In comparison to these routine BHV-1 detection techniques, ISH had an overall sensitivity of 88.2% and a specificity of 89.3% in detecting BHV-1 in aborted fetuses. Immunoperoxidase was more sensitive than ISH with tissue sections from lung (87.5% vs. 69%), liver (92% vs. 17%), spleen, and placenta; results of the tests on tissue sections from kidney were concordant. Liver sections presented special problems in that nonspecific reactions were frequently observed with hybridization. With thymus sections, the rate of detection was higher by hybridization than by IP, but the specificity of some of these reactions could not be confirmed.

Iodine deficiency impairs intellectual and neuromotor development in apparently-normal persons. A study of rural inhabitants of north-central China

Intelligence was measured by means of the Hiskey-Nebraska Test of Learning Aptitude or the Griffiths Mental Development Scales in a sample of 369 patients from iodine-deficient rural villages (Baihuyao), iodine-sufficient rural villages (Huanglo) and urban populations to test for the damaging effects of iodine deficiency on the development of the nervous system in the presumed healthy section of a community. In urban school-children who were aged seven to 14 years (n = 78), a normal range of measured intelligence was found (mean +/- SD intelligence-quotient score, 107.0 +/- 18.3). By comparison, intelligence-quotient scores were lower in all rural cohorts (a rural suppression effect) but the distribution of intelligence-quotient scores showed a further shift to the left in the iodine-deficient township. In Baihuyaon villagers who were aged 30-35 years (n = 50), who were born during the period of severe iodine deficiency, 72% of villagers had an intelligence-quotient score of less than 70 compared with 41% (P less than 0.05) of villagers who were aged 28-35 years from Huanglo, a rural iodine-sufficient control group (n = 49). Although measured intelligence was higher in Baihuyaon children whose mothers had received iodized salt - 44% of seven- to 14-year-old children had intelligence-quotient scores of less than 70 (n = 141)--it remained significantly depressed compared with rural (n = 51) and urban (n = 78) control subjects (18% and 4%, respectively). These findings were consistent with other parameters (that is, the persistently-high rate of goitre), which indicated that the salt-iodization programme was inadequate. In the iodine-deficient village, lower intelligence-quotient scores showed a relationship with the detection by audiometry of nerve deafness and with the presence of abnormal neurological signs. The latter included spasticity and pyramidal signs which were of a similar pattern to the neurological deficits that have been demonstrated in overt neurological cretins. We conclude that iodine deficiency imposes a further suppressive effect on the intellectual performance of rural inhabitants, and results in a shift of the entire population distribution of cognitive skills to a lower level.

Differential depuration of poliovirus, Escherichia coli, and a coliphage by the common mussel, Mytilus edulis

The elimination of sewage effluent-associated poliovirus, Escherichia coli, and a 22-nm icosahedral coliphage by the common mussel, Mytilus edulis, was studied. Both laboratory-and commercial-scale recirculating, UV depuration systems were used in this study. In the laboratory system, the logarithms of the poliovirus, E. coli, and coliphage levels were reduced by 1.86, 2.9, and 2.16, respectively, within 52 h of depuration. The relative patterns and rates of elimination of the three organisms suggest that they are eliminated from mussels by different mechanisms during depuration under suitable conditions. Poliovirus was not included in experiments undertaken in the commercial-scale depuration system. The differences in the relative rates and patterns of elimination were maintained for E. coli and coliphage in this system, with the logarithm of the E. coli levels being reduced by 3.18 and the logarithm of the coliphage levels being reduced by 0.87. The results from both depuration systems suggest that E. coli is an inappropriate indicator of the efficiency of virus elimination during depuration. The coliphage used appears to be a more representative indicator. Depuration under stressful conditions appeared to have a negligible affect on poliovirus and coliphage elimination rates from mussels. However, the rate and pattern of E. coli elimination were dramatically affected by these conditions. Therefore, monitoring E. coli counts might prove useful in ensuring that mussels are functioning well during depuration.

Use of an immunoperoxidase test for the detection of bovine herpesvirus-1 in aborted fetal tissue

An indirect immunoperoxidase (IP) procedure using a specific monoclonal antibody and an avidin-biotin-peroxidase complex was developed and applied to detect virus antigen in formalin-fixed, paraffin-embedded tissue sections. This IP procedure was compared with currently used diagnostic tests for detection of virus-induced abortions caused by bovine herpesvirus-1 (BHV-1). The IP procedure was applied to detect BHV-1 antigen in sections of liver and lung from 87 aborted fetuses. Sixteen of these cases were positive for viral antigen by IP staining. Sections from both liver and lung were positive in 15 of the 16 cases. A fluorescent antibody test (FA), which was applied to acetone-fixed frozen sections of liver and lung, gave positive results on 12 of the 87 fetuses, 11 of which were also positive by IP. Seven of the 12 FA-positive cases were positive on both sections of liver and lung. When FA and IP were compared. FA had a sensitivity of 67% and IP had a sensitivity of 94%. Virus was isolated from one of the 67 cases tested. The tissues in which antigen was most frequently detected by IP were liver, lung, and kidney. Distinct multifocal staining was seen in positive sections of all these tissues.

Epitope specificity of the bovine antibody response to the gIII glycoprotein of bovine herpesvirus type 1

A panel of monoclonal antibodies (MAbs) to BHV-1, specific for gI and gIII glycoproteins and for a nonglycosylated core protein p100, was used to examine the epitope specificity of the immune response to the virus in naturally exposed and experimentally infected cattle. Sera from experimentally infected calves were analyzed in a competition ELISA (C-ELISA). Antibody to an epitope on gIII appeared as early as 4 days post infection, although virus-neutralizing antibody did not appear until day 8 or later. Antibody production peaked at 13 to 18 days post infection but the level of antibody to each gIII epitope varied. Competition by sera from cattle naturally exposed to BHV-1 was analyzed as a function of the virus neutralization (VN) titer of these sera. Competition with most of the MAbs correlated linearly with neutralization titer. However, competition with 2 of the MAbs, one specific for gIII and one specific for gI, was maximal even at the lowest neutralization titer, and competition with another MAb, specific for a non-glycosylated core protein, p100, was negative. Selected sera from the naturally exposed group were also examined by radioimmunprecipitation, and were shown to react predominantly with gI, gIII and gIV glycoproteins and in a few shown to react predominantly with gI, gIII and gIV glycoproteins and in a few MAbs were determined, and it was found that neutralization was enhanced by certain combinations. A mutually exclusive relationship between neutralization enhancement and competition for binding by MAbs (as determined by reciprocal C-ELISA) indicated an epitope-specific, rather than antibody-specific, mechanism for neutralization enhancement.

Prevalence and specificity of antibodies to bovine respiratory syncytial virus in sera from feedlot and range cattle

The specificity of serum antibodies for the polypeptides of bovine respiratory syncytial virus (BRSV) was examined, using sera obtained from feedlot and range cattle. Test results in sera from feedlot cattle indicated a 60% rate of seroconversion and 95% seropositivity to BRSV, associated with lack of clinical signs indicative of respiratory tract disease. Exposure to other common respiratory tract viruses also was high (greater than or equal to 92% to bovine herpesvirus type 1, bovine viral diarrhea virus, and para-influenza virus type 3). Test results in sera from range cattle indicated BRSV seropositive rates of 28% in calves, 49% in yearling cattle, and 70% in mature cows; clinical signs of respiratory tract disease were not observed in these cattle. Antibodies to BRSV in sera from cattle in both environments reacted predominantly with polypeptides of molecular weight 80,000 through 85,000, 40,000, and 28,000. Reactivity to a glycoprotein of molecular weight between 43,000 and 44,000 and to several glycopolypeptides of smaller molecular weight increased in serum specimens obtained from feedlot cattle between time of entry into the feedlot and slaughter.

Association of bovine respiratory syncytial virus with atypical interstitial pneumonia in feedlot cattle

Thirty-three cattle with fatal respiratory tract disease were examined for gross and histologic lesions and for the presence of viral and bacterial agents in the lungs. Fifteen cattle had lesions characteristic of atypical interstitial pneumonia (AIP), and 18 had other respiratory tract diseases, including infectious bovine rhinotracheitis, shipping fever pneumonia, bronchopneumonia, pulmonary abscess, and edema of the trachea. Gross necropsy findings in the cattle with AIP were uncollapsed and emphysematous lungs; histopathologic findings included interstitial edema, thickening of alveolar walls, hyaline membrane formation, and hyperplasia of type-II pneumonocytes. The infective agents found in the lungs of the 33 cattle included bovine respiratory syncytial virus, bovine herpesvirus type 1, Pasteurella sp, mycoplasmas, and Corynebacterium pyogenes. Bovine respiratory syncytial virus was detected by use of immunofluorescence and immunoperoxidase on lung tissue sections; bovine herpesvirus type 1 was detected by these techniques and by isolation of the virus. Bovine respiratory syncytial virus was significantly (P = 0.01) associated with lesions of AIP (11 of 15), compared with those of other respiratory tract diseases (5 of 18).

Validation of disease diagnoses reported to the National Animal Health Monitoring System from a large Colorado beef feedlot

Clinical observation and collection of biological specimens from a large beef feedlot (approximately 30,0000 animals) were used to evaluate 6 approaches for validation of a disease reporting system. Data collected during a 12-month period were used to evaluate each approach. A subsample of disease cases reported to the National Animal Health Monitoring System (NAHMS) was compared with the clinical observations of the investigators. Although the agreement between clinical diagnosis by the NAHMS veterinarian and by feedlot health crews was high, the sensitivity and specificity of specific diagnoses varied from 100 to 18% and from 99 to 76%, respectively, which suggests that regular clinical observations by a veterinarian are needed to validate disease diagnoses reported to NAHMS by producers. Subsampling of a group of cattle by means of paired serologic determination of antibodies to infectious bovine rhinotracheitis virus, bovine viral diarrhea virus, bovine respiratory syncytial virus, and parainfluenza-3 virus revealed a high serologic conversion rate to infectious bovine rhinotracheitis, and high levels of preexisting antibody to bovine respiratory syncytial and parainfluenza-3 viruses. It was concluded that the current method of data collection for Colorado feedlots provides an acceptable level of sensitivity and specificity for the program. However, disease events that are not of economic importance to the feedlot operator will be underestimated. If an objective of NAHMS is to develop a base line of animal health conditions, diagnosis of diseases by current methods will be satisfactory. Occasional validation through clinical observations by a veterinarian will suffice to monitor quality of collected data.(ABSTRACT TRUNCATED AT 250 WORDS)

Detection of cytopathic and noncytopathic bovine viral diarrhea virus in cell culture with an immunoperoxidase test

Bovine viral diarrhea virus (BVDV) antigen was detected in cell culture with an indirect immunoperoxidase (IP) procedure using a specific monoclonal antibody, and an avidin-biotin-peroxidase complex. Cytopathic and noncytopathic strains of the virus showed similar patterns of IP staining until 3 days post-infection. At six days post-infection, intensity of staining decreased in cell cultures infected with noncytopathic virus, but not with cytopathic virus. The IP procedure detected BVDV antigen in cells used to isolate virus from tissues of aborted bovine fetuses and peripheral blood lymphocytes of adult cattle. Immunoperoxidase detected BVDV isolates from 10 of 44 cases of abortion of which seven of these were noncytopathic. Noncytopathic BVDV isolates from the peripheral blood lymphocytes of 7 of 65 animals were identified.

Evaluation of an antigen-capture ELISA for the detection of bovine herpesvirus type 1 shedding from feedlot cattle

A total of 457 nasal swab specimens from cases of respiratory disease in 2 feed lots were evaluated for the detection of bovine herpesvirus Type 1 (BHV-1) by ELISA. Thirty-three were found to be positive for BHV-1 by the recovery of infectious virus and 21 of these were positive by ELISA, yielding a sensitivity of 64%. Fifteen other virus isolations were made and included bovine viral diarrhea viruses, rhinoviruses and parainfluenza Type 3 viruses; none of these cases were positive with the BHV-1 ELISA. Specificity of the ELISA was 100%. Eighty percent of the specimens with BHV-1 titers greater than 10(5) TCID50 were detected by ELISA; the median amount of virus in positive specimens that were detected by ELISA was 7 X 10(5) TCID50 and the median amount of virus in specimens not detected was 1.5 X 10(4) TCID50. BHV-1 infection was most frequently diagnosed in feedlot cattle that had been in the feedlot for 40-80 days. Approximately half of the infected cattle were carrying virus-neutralizing antibodies in their serum.

Rapid, sensitive, competitive serologic enzyme-linked immunosorbent assay for detecting serum antibodies to bovine herpesvirus type 1

An enzyme-linked immunosorbent assay (ELISA) for the detection of cattle antibodies to bovine herpesvirus type 1 was developed on the basis of competition between serum antibody and a virus-neutralizing mouse monoclonal antibody. The assay showed improved sensitivity over the virus neutralization (VN) test and over an enhanced VN test in which incubation of antibody-virus mixtures was carried out for 24 h. With the ELISA, antibodies in sera from experimentally infected cattle were detected earlier after infection and showed more rapid increases in levels. A comparison of the ELISA with the VN tests by using a set of 85 field sera with low levels of antibodies demonstrated that the ELISA was the most sensitive test, detecting 10 positive serum samples that were negative by the VN tests. The ELISA was inexpensive, rapid, and highly reproducible and showed a significant improvement in sensitivity over VN tests.

Shedding of enteric coronavirus in adult cattle

Electron microscopic examination of fecal specimens from adult dairy cows indicated seasonal coronavirus shedding. Fifty-two cows from a 300 cow herd were monitored for shedding of coronavirus. Approximately 50% to 60% of the cows monitored shed coronavirus during the winter months (November to March) of the first year of the study. During 2 subsequent years of monitoring the same cows, 20% to 30% of the cows shed coronavirus during the winter months. Virus shedding was not detected during the summer months (July to September). Half of the cows monitored were vaccinated with a modified-live rotavirus-coronavirus-Escherichia coli combination vaccine; however, vaccination did not influence seasonal shedding of coronavirus, as compared with shedding in the nonvaccinated cows. In nonvaccinated cows that calved in the winter months, the incidence of coronavirus shedding increased from 20% to 30% during the last 2 months of gestation to 65% to 70% at parturition. In vaccinated cows, the incidence of shedding did not increase at parturition.

Detection of bovine herpesvirus 1 DNA immobilized on nitrocellulose by hybridization with biotinylated DNA probes

A molecular hybridization technique using biotinylated DNA probes was used to detect bovine herpesvirus 1 (BHV-1) nucleic acid species immobilized on nitrocellulose. Seventeen recombinant plasmids containing HindIII restriction fragments of the BHV-1 genome were compared for their ability to detect immobilized BHV-1 DNA from purified virus and infected cells. One probe, pCB2, labeled by nick translation with either 3H or biotin, detected as little as 10 pg of viral DNA. In time course experiments, BHV-1 DNA could be detected by 2 h postinfection in 10(6) infected cells. BHV-1 DNA was detected in nasal swabs and exudate from experimentally infected cattle, even when specimens had been stored for over a year. In a retrospective study of a respiratory disease outbreak in a feedlot, hybridization was compared with virus isolation for diagnosis of BHV-1 infections. The sensitivity rate was 0.68 with virus isolation as the referent standard. Blot hybridization provides a novel approach with unique applications for the diagnosis of bovine herpesvirus infections.

Influence of age and body proportions on weight loss of obese women after treatment

At the conclusion of a treatment program for obesity, the influence of age and several pretreatment measures of body proportion (weight, height, symphysis height, finger tip span, body surface area, and linearity index) on weight loss were assessed. All 42 volunteering females lost weight; however, the extent of loss was uninfluenced by the above variables. Weight loss was highly correlated with changes in measures of body surface (.77) and linearity (— .92).

A single dilution enzyme-linked immunosorbent assay for the quantitative detection of antibodies to bovine herpesvirus type 1

Three serological assays were compared for detection of antibodies to bovine herpes-virus type 1. These were virus neutralization (VN), enhanced complement fixation (CF) and enzyme-linked immunosorbent assay (ELISA). The ELISA was developed using an infected cell lysate antigen and purified virus and was optimized in relation to antigen and antisera dilutions. The CF assay was enhanced by the addition of bovine complement. These 3 assays were compared for detection of: specific virus antibody titers; sero-conversions; early antibody response in experimentally-infected cattle. Both ELISA end-point titers and single dilution values were found to be more sensitive than the CF or VN assays for specific antibody level quantitation. With a single dilution ELISA test procedure a correlation was obtained between ELISA values and VN titers. Using the single dilution ELISA test the assay also detected antibodies in experimentally-infected cattle before either the VN or CF assays, and agreed with the VN test in 35/38 seroconversions found by 4-fold or more VN changes between acute and convalescent paired sera from naturally-infected animals. The single dilution ELISA was a rapid and sensitive test for routine antibody detection in bovine sera.

Neutralizing determinants defined by monoclonal antibodies on polypeptides specified by bovine herpesvirus 1

Monoclonal antibodies were used to study neutralizing determinants on polypeptides of bovine herpesvirus 1. Two of three monoclonal antibodies which recognized nonoverlapping epitopes on a glycoprotein of 82,000 daltons were found to neutralize. A second group of monoclonal antibodies that individually precipitated five viral glycopolypeptides ranging in size from 102,000 to 55,000 daltons also neutralized. Two monoclonal antibodies which were the most efficient in neutralization recognized a non-glycosylated protein of 115,000 daltons which was the major polypeptide on the virus. A fourth group of monoclonal antibodies precipitated a non-glycosylated polypeptide of 91,000 daltons and several smaller polypeptides, but these antibodies demonstrated only limited neutralizing activity.

Rapid detection of canine parvovirus in feces using monoclonal antibodies and enzyme-linked immunosorbent assay

Monoclonal antibodies were used to develop a double antibody enzyme-linked immunosorbent assay for the detection of canine parvovirus (CPV) antigen in fecal samples. The assay was specific for the hemagglutinating protein of CPV and detected as little as 1.5 ng of virus within a 15-minute incubation period. The use of monoclonal antibodies against 2 epitopes on the CPV antigen permitted the simultaneous addition of test sample and enzyme-conjugated antibody, thus considerably simplifying the manipulations required for the assay. Results were visually determined without special instrumentation. Clinical studies revealed greater than 95% correlation between enzyme-linked immunosorbent assay results and hemagglutination titers.

Comparison of enzyme-linked immunosorbent assay, DNA hybridization, hemagglutination, and electron microscopy for detection of canine parvovirus infections

Canine fecal samples were analyzed by enzyme-linked immunosorbent assays (ELISA) by using monoclonal antibodies to the canine parvovirus hemagglutinating protein. These data were compared with results obtained with DNA hybridization assays, hemagglutination assays, and electron microscopy. The highest correlation was observed between the ELISA and the hemagglutination tests, with 94.4% of samples showing agreement. Lower correlation was obtained between ELISA and DNA hybridization tests (73.3%). Correlation between ELISA and electron microscopy was 60.9%. The studies indicated that the ELISA can be used as a sensitive and specific diagnostic assay for canine parvovirus infections.

Comparison of phage typing, plasmid mapping, and antibiotic resistance patterns as epidemiologic markers in a nosocomial outbreak of methicillin-resistant Staphylococcus aureus infections

Isolates of methicillin-resistant Staphylococcus aureus obtained during a nosocomial outbreak were analyzed by phage typing, plasmid mapping, and antibiotic susceptibility patterns for epidemiologic markers. Antibiotic susceptibility patterns were of limited use epidemiologically because of multiple resistance and similarity of the strains. Phage typing demonstrated that the outbreak consisted of multiple introductions of MRSA organisms into the hospital from the community and from other hospitals, and of circulation of one predominant phage type, 6/47/54/81. Plasmid mapping further subdivided the organisms of this phage type into two different groups, one of which carried two particular plasmids. Organisms carrying these plasmids were significantly more resistant to methicillin and cephalosporins and were isolated from patients who had received prior antibiotic treatment.

Body shape perception and its disturbance in anorexia nervosa

The perception of body shape was studied in 15 female patients with anorexia nervosa and 15 age matched controls. A lens was used which could be manipulated to cause a horizontal distortion of an image projected onto a video monitor. The patients showed a greater tendency to over- and under-estimate their present body shape than did the controls. Further, the patients' desired body shape was significantly thinner than that of controls, as was their estimation of what constitutes a normal body shape. These findings are discussed in relation to the literature and it is suggested that they may have important implications for treatment.