Antigens of Amblyomma americanum ticks recognized by repeatedly infested sheep

Sera were taken from 3 sheep that had been infested 5 times with Amblyomma americanum and that exhibited manifestations of humoral depression to homologous antigens and anti-tick resistance. Proteins extracted from the intestine or salivary glands of unfed ticks or salivary glands from partially (3-day) fed ticks were analyzed by polyacrylamide gel electrophoresis (PAGE) and sodium dodecyl sulfate-PAGE. Antigens recognized by the sheep in the same materials before and after each infestation were analyzed by western blots. The sheep responded to 44 antigens. Nine to 23 antigens were recognized by the preinfestation sera and the sera of 2 gnotobiotic sheep. Four antigens (34,000, 36,500, 38,000, and 115,000 MW) were revealed conspicuously by the serum of the first infestation but very weakly or not at all by the sera of the third infestation onward. Two antigens (35,500 and 29,000 MW) from fed salivary glands were revealed only by sera taken after manifestations of resistance had appeared. These antigens may be responsible for anti-tick protection. The 29,900 MW antigen was present also in salivary extracts of Boophilus microplus.     

Biologic properties and nucleotide sequence analysis of human papillomavirus type 51.

Human papillomaviruses (HPVs) may be grouped according to the site from which they are isolated and the disease with which they are associated. We recently identified and cloned HPV type 51 (HPV-51) from a low-grade precancerous lesion (G. Nuovo, E. DeVilliers, R. Levine, S. Silverstein, and C. Crum. J. Virol. 62:1452-1455, 1988). Molecular epidemiologic analysis of cervical lesions, including condylomata and low- and high-grade precancers, revealed that HPV-51 was present in about 5% of the samples we examined. We have now determined the complete nucleotide sequence of this virus and compared it with other sequenced HPVs. Our analysis reveals that the 7,808-bp genome is composed of eight open reading frames which are encoded on the same strand and that this virus is most closely related to HPV-31. Sequence comparisons place this virus in the group of high-risk viruses (those with an increased risk of progressing to malignancy) along with HPV-16, -18, -31, and -33. Morphologic transformation experiments demonstrated that HPV-51 had transformation potential and that transformed cells contained RNAs homologous to E6 and E7.     

Characterization of cloned chicken anemia virus DNA that contains all elements for the infectious replication cycle.

Circular double-stranded replication intermediates were identified in low-molecular-weight DNA of cells of the avian leukemia virus-induced lymphoblastoid cell line 1104-X-5 infected with chicken anemia virus (CAV). To characterize the genome of CAV, we cloned linearized CAV DNA into the vector pIC20H. Transfection of the circularized cloned insert into chicken cell lines caused a cytopathogenic effect, which was arrested when a chicken serum with neutralizing antibodies directed against CAV was added. Chickens inoculated at 1 day of age with CAV collected from cell lines transfected with cloned CAV DNA developed clinical signs of CAV. The 2,319-bp cloned CAV DNA contained all the genetic information needed for the complete replication cycle of CAV. The CAV DNA sequence has three partially overlapping major reading frames coding for putative peptides of 51.6, 24.0, and 13.6 kDa. The CAV genome probably contains only one promoter region and only one poly(A) addition signal. Southern blot analysis using oligomers derived from the CAV DNA sequence showed that infected cells contained double- and single-stranded CAV DNAs, whereas purified virus contained only the minus strand. It is the first time that the genome of one of the three known single-stranded circular DNA viruses has been completely analyzed.     

Organic anion transport study in mutant rats with autosomal recessive conjugated hyperbilirubinemia

The EHBR is a mutant rat strain with congenital conjugated hyperbilirubinemia bred from a Sprague-Dawley rat. Transport of conjugated bilirubin, indocyanine green, and tetrabromosulfophtalein from liver to bile is severely impaired in these rats. Serum bilirubin amounts to 6.0 +/- 0.05 mg/dl (n = 4) in adult rats, with 97% conjugates. The bile flow is reduced to about 65% of the control group, whereas total bile acid in 10-min bile samples is similar. Liver histology of 10 week-old rats revealed neither intracellular pigmentation nor architectural abnormalities.     

Lung contains an inhibitor for nicotinatemononucleotide pyrophosphorylase (carboxylating) of NAD biosynthesis

Rat, cow and foal lung extracts contained an inhibitor for the liver NAD biosynthetic-pathway enzyme, nicotinatemononucleotide pyrophosphorylase (carboxylating) [EC 2.4.2.19]. The inhibitor was not dialyzable, was labile at 100 degrees C, was retained by a 30,000 dalton pore size Amicon membrane and, when partially purified by precipitation at 40-100% ammonium sulfate, inhibited the enzyme stoichiometrically. Lung reportedly does not contain nicotinate-mononucleotide pyrophosphorylase or make NAD de novo. However, the inhibitor would mask detection of the enzyme in lung extracts. We detected a low nicotinatemononucleotide pyrophosphorylase-like activity (0.003 +/- 0.001 nanomoles CO2 produced from quinolinic acid per mg of extract protein) in rat lung but none in foal or cow lung.     

Molecular biological study of the vaccinia virus genome. IV. The late nonstructural 36K protein of vaccinia virus is vitally important

Two genetics markers: the herpes simplex virus thymidine kinase and Escherichia coli beta-galactosidase genes were inserted into the 36K protein gene of vaccinia virus located in a HindIII-P DNA fragment. An unstability of recombinant viruses with Lac(+)-phenotype were discovered. A mechanism of viruses unstable variants formation was proposed, it was confirmed by the results of hybridisation analyses of virus recombinant genomes. The importance of a late nonstructural 36K protein gene for virus reproduction was demonstrated.     

Organotin compounds induce aneuploidy in human peripheral lymphocytes in vitro

In vitro exposure of PHA-stimulated human lymphocytes to organotin compounds resulted in statistically significant increases in the frequencies of hyperdiploid cells. When taken together with our previous study demonstrating spindle inhibiting effects of the same organotin compounds by an indirect method (Jensen et al., 1989), the present study strongly indicates that organotin compounds are able to induce aneuploidy, probably by affecting spindle function.