Eradication of ovine pulmonary adenocarcinoma by motherless rearing of lambs.

The principles of maedi-visna eradication programmes were applied to a field trial for the eradication of ovine pulmonary adenocarcinoma (OPA). In two maternal flocks the prevalence of gross and histological lesions in slaughtered animals was 18.3 per cent and 29.8 per cent, respectively. The lambing period was supervised for three consecutive years from 1999 to 2001, during which the lambs were taken away from their mothers at birth, deprived of maternal colostrum, and hand-reared away from other sheep. Over the three-year period, 322 hand-reared animals, mainly male lambs between 10 and 14 months old, were slaughtered; their lungs were examined grossly, 52.5 per cent of them were examined histologically, and 105 samples of caudal mediastinal lymph nodes were examined by PCR. No OPA tumours were detected in the slaughter specimens from the derived flock, but one lamb had histological lesions in one lung location; intrauterine transmission was ruled out in this case. No clinical OPA has subsequently been observed in the hand-reared flock. Bronchoalveolar lavage samples from the breeding stock were examined by PCR in order to rule out further subclinical cases of OPA. No Jaagsiekte retrovirus was detected in any of the 488 samples.

PCR examination of bronchoalveolar lavage samples is a useful tool in pre-clinical diagnosis of ovine pulmonary adenocarcinoma (Jaagsiekte).

Ovine pulmonary adenocarcinoma (OPA) is a contagious lung tumour of sheep caused by Jaagsiekte sheep retrovirus (JSRV). The disease is a particular problem in flocks in many parts of the world. The aim of the study was to assess screening methods for individual animals as a prelude to future eradication trials. Results of histological examination were used as the standard to evaluate the relative sensitivity and specificity of an established heminested polymerase chain reaction (PCR) test for JSRV proviral DNA from blood and bronchoalveolar lavage (BAL) samples. PCR results from tissue samples are included as control data. PCR testing of blood samples was found to have an estimated sensitivity of only 10% (95% confidence interval (CI) 3-20) while the sensitivity of the PCR test on BAL samples was 89% (CI 79-96) in comparison to the results of histological examination. We conclude that PCR testing of BAL samples is an effective confirmatory test for sheep with suspected clinical OPA. It is also a useful tool for the pre-clinical identification of individual infected sheep within an infected flock and therefore may prove beneficial in future control or eradication programmes.

Jaagsiekte sheep retrovirus can be detected in the peripheral blood during the pre-clinical period of sheep pulmonary adenomatosis.

Peripheral blood leukocytes (PBLs) and tissue samples from 36 sheep were examined for jaagsiekte sheep retrovirus (JSRV) by hemi-nested PCR. Animals were classified according to the status of sheep pulmonary adenomatosis (SPA), which was confirmed by pathological examination, as follows: (i) sheep with classical SPA (cSPA, n=10), (ii) sheep with atypical SPA (aSPA, n=6), (iii) non-affected sheep from SPA-affected flocks (in-contact, n=10) and (iv) non-affected sheep from SPA-free flocks (control, n=10). JSRV proviral DNA was detected in the PBLs of 10/10 cSPA, 5/6 aSPA, 4/10 in-contact and 0/10 control sheep. Lung tumours and lymphoid organs were also found to be JSRV-positive. The number of positive PCR results was greater for sheep in the cSPA group than for those in the aSPA and in-contact groups. For the first time, it is concluded that JSRV can be detected in naturally infected sheep before the onset of clinical disease and even before the development of discernible tumours.

Faecal elastase 1: a marker of exocrine pancreatic insufficiency in cystic fibrosis.

Pancreatic elastase 1 (E1), a digestive protease, is synthesized by the acinar cells of the pancreas. Using an enzyme-linked immunosorbent assay, we evaluated stool E1 levels in the following groups of patients. (a) Specimens submitted for occult blood examination from 20 adults, over 3 consecutive days, to assess the inter-day variability in E1 excretion. There were no symptoms suggestive of pancreatic insufficiency in this group. The mean E1 concentration over all samples was 457 micrograms E1/g stool (range 124-1683). The intra-assay variation was 6.4% (n = 14) and the inter-assay variation was 8.8% (n = 12). The mean intra-patient variation was 17%. (b) Cystic fibrosis (CF) patients. Eight patients had E1 levels in the reference range (> 200 micrograms E1/g stool). The remaining 25 patients had undetectable E1 levels. (c) A control group of children presenting with unexplained bronchiectasis and/or recurrent respiratory infections and no symptoms of pancreatic dysfunction. The mean E1 concentration in the group was 519 micrograms E1/g stool (range 139-1941). There was no significant difference in E1 concentrations between the two non-CF groups, nor between the pancreatic-sufficient CF patients when compared with both non-CF groups. There was a significant difference between the pancreatic-sufficient and -insufficient CF groups (P < 0.001) using the Mann Whitney U test. All fifteen CF patients who were delta F508 homozygotes had undetectable E1. It may be possible to relate CF genotype to the presence or absence of E1 and to the degree of pancreatic insufficiency. Measurement of faecal E1 in children with CF appears to differentiate them into a group of children with normal pancreatic function and a larger group with severe insufficiency.

Analysis of creatine and creatinine in urine by capillary electrophoresis.

Creatine is found in the urine of subjects ingesting creatine monohydrate as an ergogenic aid. Creatinine, the catabolic breakdown product of creatine, is a major constituent of normal urine. It is of interest to follow the excretion of creatine and creatinine in urine as a function of time after creatine ingestion. In this study, creatine and creatinine were analyzed in urine by capillary electrophoresis. The optimization of the method was discussed, with the best results being obtained using a 30 mM phosphate-150 mM sodium dodecyl sulfate buffer at pH 6, with the detector set at 214 nm and an applied voltage of 15 kV across a 45 cm capillary. Verification of the method was provided by HPLC analysis and spiking. The application of the method was demonstrated by analysis of creatine and creatinine in urine samples collected in a 24-h period following creatine ingestion.

Lack of a specific immune response against a recombinant capsid protein of Jaagsiekte sheep retrovirus in sheep and goats naturally affected by enzootic nasal tumour or sheep pulmonary adenomatosis.

Enzootic nasal tumour (ENT) and sheep pulmonary adenomatosis (SPA) are two contagious adenocarcinomas of the respiratory tract of sheep and goats. Both diseases are associated with related, but distinct, type-D-retroviruses (ENTV and JSRV respectively). No evidence of circulating antibodies has been described in animals affected by either ENT or SPA using antigens from natural sources. We evaluated the usefulness of a recombinant JSRV capsid protein (JSRV-CA) as antigen to study the antibody responses of animals naturally affected by ENT or SPA, using immunoblotting. Positive reactions were detected in the sera of both affected and unaffected sheep and goats. The reactivity was abolished completely by absorption with the GST fusion partner but not by JSRV-CA, suggesting that it was not specific. The results support prior observations indicating that sheep and goats infected by JSRV and ENTV do not develop specific humoral responses to these retroviruses.

Epithelial tumour cells in the lungs of sheep with pulmonary adenomatosis are major sites of replication for Jaagsiekte retrovirus.

Sheep pulmonary adenomatosis (SPA) is a naturally occurring contagious lung tumour of sheep which has been associated aetiologically with a type D- and B-related retrovirus (Jaagsiekte retrovirus; JSRV). To improve understanding of the aetio-pathogenesis of SPA, the distribution and the sites of JSRV replication in sheep with naturally or experimentally induced SPA or in unaffected controls were identified. New immunological reagents were produced and a blocking enzyme-linked immunosorbent assay (B-ELISA) and an immunohistochemical technique for the detection of JSRV major capsid protein at the tissue and cellular levels were developed. JSRV was detected only in the respiratory tract of sheep affected by pulmonary adenomatosis and specifically in the transformed epithelial cells of the alveoli of SPA-affected sheep.

Experimental transmission of enzootic intranasal tumors of goats.

The successful experimental transmission of enzootic intranasal tumor (EIT) from goat to goat is described. Ten kids, less than 48 hours old, from a flock free of the disease and seronegative for ruminant lentiviruses were inoculated intranasally or intrasinusally with either nasal fluid from goats with naturally occurring EIT or EIT retrovirus concentrated from such fluids. EIT was induced in three kids after 12-24 months. The EIT retrovirus was demonstrated in tumor material from each of the three kids by western blotting and electron microscopy. All kids were seronegative for ruminant lentiviruses.

Enzootic nasal tumour of goats: demonstration of a type D-related retrovirus in nasal fluids and tumours.

Nasal exudate and tumour tissue from goats with enzootic nasal tumours were shown to contain a reverse transcriptase activity associated with a particle of buoyant density typical of retroviruses. The same particle contained a 25,000 Mr protein that cross-reacted with the p27 of Mason-Pfizer monkey virus (MPMV) and with p25 of sheep pulmonary adenomatosis retrovirus. It also contained a low Mr protein related to p10-12 of MPMV.

Pneumonia of lambs following inoculation of isolates of sheep herpesvirus (caprine herpesvirus 1) of different DNA genotypes.

One-day-old, specific pathogen-free lambs, were equally susceptible to infection with three isolates of caprine herpesvirus 1 (CHV1). One of these isolates was genomically different by DNA analysis. Lesions, which were confined to the lung, ranged from a mild interstitial reaction to widespread consolidation. CHV1 was recovered from lungs and less commonly from liver and adrenal gland. Three-week-old SPF lambs were also successfully infected with CHV1. Histopathological findings were similar to those in 1-week-old lambs.

Association of MHC antigens with susceptibility to and severity of rheumatoid arthritis in multicase families.

A study of HLA association with rheumatoid arthritis (RA) in multicase families has been performed in north east England. Two hundred and nineteen individuals from 13 families were assessed for the presence of RA, and all were HLA typed. Thirty-nine were found to have classical or definite RA by American Rheumatism Association (ARA) criteria. Thirty-five (90%) of these possess HLA-DR4, confirming the previously reported association of RA with DR4. A further 19 individuals were found to have probable RA or gave a convincing history of previous inflammatory polyarthritis. Thirteen (68%) of these possess HLA-DR4, and this is not significantly different from non-affected family members of whom 63% possess DR4. These results suggest that HLA-DR4 is associated only with the more severe forms of RA. Homozygosity for HLA-DR4 was not associated with either earlier onset or more severe disease when compared with heterozygous DR4. Possession of the haplotype most commonly inherited with the RA in individual families was not associated with earlier onset but may be associated with more severe disease. The severity of RA appears to be influenced by the major histocompatibility complex (MHC) in these families.

HLA-DR antigens in primary biliary cirrhosis: lack of association.

A study of HLA-DR antigen in 75 patients with primary biliary cirrhosis has been carried out in order to test the hypothesis that genetic factors related to genes controlling immune responses might be important in the pathogenesis of primary biliary cirrhosis. The frequencies of HLA-DR locus antigens was not significantly different from those in 200 normal controls, nor were those of tissue antigens on the A and B loci. No HLA-DR antigen was significantly associated with the appearance of granulomata on liver biopsy (possibly good prognosis) or with raised serum bilirubin (possibly bad prognosis); nor was there any association between any HLA-DR antigen and adverse reactions to D-penicillamine treatment in 17 patients with such adverse reactions. It is concluded that genetic traits related to HLA antigens studied are probably not important in the aetiology of the disease.

Bile reflux and degree of gastritis in patients with gastric ulcer: before and after operation.

The incidence and degree of bile reflux and gastritis has been measured in normal subjects and in patients with gastric ulcer before operation and after treatment by highly selective vagotomy with ulcer excision, Billroth 1 partial gastrectomy, and truncal vagotomy and drainage. Before operation patients had significantly higher (P less than 0.001) bile acid concentrations in the stomach than normal subjects. Treatment by highly selective vagotomy resulted in significantly lower bile acid concentrations than those before operation and those found after Billroth 1 partial gastrectomy. Antral and body gastritis was significantly less in normal subjects than in the preoperative and all postoperative groups. There was no significant difference in antral or body gastritis between the preoperative gastric ulcer patients and the patients after any of the surgical procedures despite the significant differences in bile acids. Though highly selective vagotomy in the treatment of gastric ulcer results in a reduction in duodenogastric reflux of bile there is no improvement in the gastritis that is present.

HLA antigens and spinal muscular atrophy.

Fifty-four patients with spinal muscular atrophy were examined and HLA typing performed on blood from each. A, B and DR antigens were determined. No statistical difference in antigen prevalence was found between patients and a control population. The clinical and genetic heterogeneity found in this disorder does not appear to be related to HLA status.

Bile acid and lysolecithin concentrations in the stomach in patients with duodenal ulcer before operation and after treatment by highly selective vagotomy, partial gastrectomy, or truncal vagotomy and drainage.

Duodenogastric reflux of bile acids and lysolecithin in the course of a standard test meal was measured in normal people and in patients with duodenal ulcer before operation and more than one year after highly selective vagotomy, Polya partial gastrectomy, truncal vagotomy and pyloroplasty, and truncal vagotomy and gastrojejunostomy. Before operation, duodenal ulcer patients had significantly higher fasting, post-prandial, and peak bile acid concentrations in the stomach than had normal subjects. After Polya partial gastrectomy, fasting, post-prandial, and peak concentrations of bile acids and lysolecithin were significantly higher than in preoperative duodenal ulcer patients. After highly selective vagotomy, in contrast, bile acid concentrations in the stomach were significantly lower than in preoperative duodenal ulcer patients and post-prandial and peak lysolecithin concentrations were less than half (NS) those recorded in preoperative duodenal ulcer patients. After highly selective vagotomy, bile acid concentrations were also significantly lower than bile acid concentrations after Polya partial gastrectomy, truncal vagotomy and pyloroplasty, and truncal vagotomy and gastrojejunostomy; and post-prandial and peak lysolecithin concentrations were significantly lower than after Polya partial gastrectomy and truncal vagotomy and gastrojejunostomy. Thus, when used in the treatment of patients with duodenal ulcer, highly selective vagotomy keeps ;bile' out of the stomach, probably through its effect on gastric smooth muscle, combined with the preservation of an intact antropyloroduodenal segment. In contrast, Polya partial gastrectomy, truncal vagotomy and gastrojejunostomy, and truncal vagotomy and pyloroplasty all lead to a significant increase in reflux of bile acids and lysolecithin into the stomach. The clinical importance of these findings is that both gastritis and, in the long term, gastric carcinoma may prove to be less common after highly selective vagotomy than after partial gastrectomy or vagotomy with a drainage procedure.