Detection of Jembrana disease virus in spleen, lymph nodes, bone marrow and other tissues by in situ hybridization of paraffin-embedded sections.

Jembrana disease virus (JDV) is a lentivirus that causes an acute, severe disease syndrome in infected Bali cattle in Indonesia. An in situ hybridization technique was developed that detected JDV genomic RNA in formalin-fixed paraffin-embedded tissue sections, using a digoxigenin-labelled riboprobe. Large numbers of JDV-infected cells were demonstrated in many tissue sections from experimentally infected animals early in the disease course, which was consistent with the extremely high circulating viraemia previously reported to occur during the febrile phase. The number of infected cells was consistently highest in sections of spleen, followed by many other tissues including lymph nodes, lungs, bone marrow, liver and kidney. Infected cells were also identified in the general circulation and within unusual intravascular lesions in lung sections. The relatively high level of infection found in bone marrow suggested that its involvement may be important in the disease pathogenesis, as it is with other lentiviruses.

Recent advances in the understanding of Jembrana disease.

Jembrana disease is a severe and acute clinical disease in Bali (Bos javanicus) cattle with a case fatality rate of about 20%, and a mild sometimes subclinical disease in other cattle types and buffalo. The aetiological agent has been identified as a lentivirus, designated as Jembrana disease virus (JDV). Preliminary sequence analysis has confirmed the identity of JDV as a lentivirus and has shown that it is distinguishable from BIV. There is antigenic cross-reactivity between the capsid protein of JDV and the previously identified bovine lentivirus designated bovine immunodeficiency virus (BIV). Serological tests that detect antibody to the capsid protein of JDV or BIV would not differentiate between antibody due to infection by either virus. The diseases induced by BIV and JDV infection in cattle are very different, and the pathogenesis of JDV infection in Bali cattle is unusual for a lentivirus infection.

Nucleotide sequence analysis of Jembrana disease virus: a bovine lentivirus associated with an acute disease syndrome.

The complete nucleotide sequence of the RNA genome of Jembrana disease virus (JDV), a lentivirus that causes an acute disease syndrome in Bali cattle (Bos javanicus), is reported. In addition to the gag, pol and env genes and flanking long terminal repeats (LTRs) that characterize all retroviruses, a number of accessory genes represented by small multiply spliced ORFs in the central and 3'-terminal regions of the genome, including tat and rev that are typical of lentiviruses, were identified. The genome of JDV was 7732 bp in length, 750 bp smaller than the genome of bovine immunodeficiency virus (BIV) strain BIV127. A striking feature of the genome was the many deletions relative to BIV127, the largest of which were 471 bp from the env gene and 157 bp from the U3 (promoter) region in the LTR. There were also several insertions of up to 33 bp in the JDV genome relative to BIV127 found in the env gene and small ORFs that overlap env. Other significant genomic differences between JDV and BIV127 included changes to cis-acting sequences throughout the genome such as promoter and enhancer sequences in the LTR, the trans-activation response region, splice sites and frameshift sequences; alterations to the gag precursor protein cleavage sites and thus the processed products; loss of the vpw and vpy ORFs; and amino acid changes in all coding regions. The significance of these changes is discussed in relation to the differences in pathogenicity between JDV and BIV.

Genomic sequence analysis identifies Jembrana disease virus as a new bovine lentivirus.

Jembrana disease virus, the cause of an acute, severe disease in Bali (Bos javanicus) cattle in Indonesia was recently identified as a retrovirus, and possibly a lentivirus. We have produced sequence data representing 598 bp of the pol gene, amplified by PCR from viral cDNA using broadly reactive universal primers for retroviruses and more specific genus-reactive primers for lentiviruses. When the sequence data were compared with that of known lentiviruses and other bovine retroviruses, the closest alignment was with bovine immunodeficiency-like lentivirus (BIV), showing 74% nucleotide sequence identity. This confirmed that JDV is a lentivirus and that it is distinguishable from BIV. The pathogenesis of Jembrana disease is most unusual for a lentivirus infection and differs markedly from that reported for BIV infection.

Failure to augment maximal limb blood flow in response to one-leg versus two-leg exercise in patients with severe heart failure.

Lower limb blood flow, oxygen uptake, and femoral vein O2 content were measured at rest and during maximal bicycle exercise, performed with two legs and one leg, in four normal subjects and in five patients with severe congestive heart failure. While in normal subjects femoral vein blood flow and lower limb vascular conductance were significantly greater during one-leg exercise than during two-leg exercise (6084 +/- 745 vs 5370 +/- 803 ml/min, p less than .05, and 52.3 +/- 8.0 vs 45.1 +/- 8.2 U X 10(3), p less than .05, respectively), in patients with severe congestive heart failure these values were similar during the two forms of exercise (1082 +/- 459 vs 1053 +/- 479 ml/min and 9.6 +/- 3.7 vs 9.4 +/- 3.5 U X 10(3), respectively). In five additional patients, one-leg maximal bicycle exercise was performed before and after administration of phentolamine into the femoral artery of the active leg. Regional alpha-adrenergic blockade with phentolamine did not alter maximal oxygen uptake attained during one-leg bicycle exercise (9.8 +/- 1.5 vs 10.3 +/- 1.9 ml/kg). Lower limb blood flow and femoral vein O2 content attained during maximal one-leg exercise were also similar before and after phentolamine. Thus, in contrast with normal subjects, patients with severe congestive heart failure were unable to further increase limb blood flow during one-leg bicycle exercise. Moreover, local alpha-adrenergic blockade does not augment blood flow to the active limb during maximal one-leg bicycle exercise. This suggests that the ability of the muscular vasculature to vasodilate during exercise is impaired and may be a limiting factor to maximal exercise capacity in such patients.