DNA-dependent RNA polymerase from bacteriophage T3 transcribes and amplifies an RNA template in vitro.

RNA-based amplification systems that have been recently described are dependent upon the presence of more than one enzyme. In an attempt to minimize the number of polymerases required for efficient amplification, we have studied the template specificity of bacteriophage T3 RNA polymerase. A synthetic bacteriophage T3 promoter was covalently attached to an RNA template. The T3 promoter-RNA complex was found to be selective for its native polymerase, and dependent upon the presence of all four ribonucleoside precursors. The product of the RNA-directed transcription is complementary to the initial template.

Effects of dichlorvos treatment on mouse reproduction.

To test whether exposure to dichlorvos vapors for treatment of mouse ectoparasites resulted in temporary cessation of breeding, we exposed harem breeding groups of mice to varying concentrations of dichlorvos vapors and examined the effects of exposure on litter frequency and litter size. All exposure levels resulted in decreased plasma cholinesterase concentrations in treated mice for up to 10 days following the completion of exposure. Litter frequency and size were unaffected by dichlorvos exposure, and gestation times were not prolonged. Therefore, treatment with dichlorvos vapors during breeding did not affect reproduction in exposed mice.

Site-directed transcription initiation with a mobile promoter.

A method is described for the high-level transcription of any DNA segment using bacteriophage RNA polymerases (RNAPs). A synthetic mobile promoter with a template-complementary 3' extension is ligated to the target sequence of interest. Transcription with an appropriate RNAP results in an amplification of approx. 70-fold. In the presence of heterologous DNA, bacteriophage RNAPs are shown to be specific for their cognate mobile promoters.

Genomic organization and sequence of the Gus-s alpha allele of the murine beta-glucuronidase gene.

The Gus-s alpha allele of the mouse beta-glucuronidase gene exhibits a high degree of inducibility by androgens due to its linkage with the Gus-r alpha regulatory locus. We isolated Gus-s alpha on a 28-kilobase pair fragment of mouse chromosome 5 and found that it contains 12 exons and 11 intervening sequences spanning 14 kilobase pairs of this genomic segment. The mRNA cap site was identified by ribonuclease protection and primer extension analyses which revealed an unusually short 5' noncoding sequence of 12 nucleotides. Proximal regulatory sequences in the 5'-flanking DNA and the complete sequence of the Gus-s alpha mRNA transcript were also determined. Comparison of the amino acid sequence determined from the Gus-s alpha nucleotide sequence with that of human beta-glucuronidase indicated that the two human mRNA species differ due to alternate splicing of an exon homologous to exon 6 of the mouse gene.

A dot-immunobinding assay for the serodiagnosis of Pasteurella multocida infection in laboratory rabbits.

A dot-immunobinding assay was developed to detect serum IgG specific for lipopolysaccharide of rabbit isolates of P. multocida. The assay detected serum IgG as early as 1 week after experimental subclinical nasal infection, whereas 8 weeks were required to detect antibody by a gel diffusion precipitin test. The assay was more reliable than nasal cultures, in that up to 46% of 16 weekly nasal washings of some infected rabbits failed to yield P. multocida. The bacterial antigen (proteinase k digested cell lysate) used in the assay reacted with IgG that did not cross-react with lipopolysaccharide antigens of B. bronchiseptica, P. pneumotropica or P. hemolytica. The assay is sensitive and specific, easily performed, cost effective, requires no special laboratory instruments and provides a permanent easily stored record.

Pasteurellosis in laboratory rabbits: characterization of lipopolysaccharides of Pasteurella multocida by polyacrylamide gel electrophoresis, immunoblot techniques, and enzyme-linked immunosorbent assay.

The lipopolysaccharides (LPSs) of five isolates of Pasteurella multocida from rabbits were characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, immunoblots, and enzyme-linked immunosorbent assay. Silver-stained sodium dodecyl sulfate-polyacrylamide gel electrophoresis profiles of purified unaggregated LPSs resembled those of semirough strains of gram-negative enterobacteria and consisted of one or two bands that migrated within an interval just ahead or slightly behind the migration of the Ra chemotype of "Salmonella minnesota," which has a molecular size of 4.3 kilodaltons. Polyclonal rabbit antisera to P. multocida whole cells used in Western blots and enzyme-linked immunosorbent assays of unabsorbed and LPS-absorbed antisera revealed that the LPS of these isolates of P. multocida contained at least two types of antigens: a nonserospecific antigen and a serospecific antigen. The LPSs of four isolates each had a different serospecific antigen. The nonserospecific antigen was expressed in two isolates and was the only demonstrable LPS antigen in one other isolate.

Long-term effect of 2-hydroxyethyl retinamide on urinary bladder carcinogenesis and tumor transplantation in Fischer 344 rats.

The effects of HER upon early and late stages of BBN-induced bladder cancer in rats were examined. Female Fischer 344 rats were administered HER in the diet either before and during or continuously after BBN administration and were monitored periodically for up to 2 years. The total dose of BBN was 600 mg administered over a 6-week period. In a separate experiment, the effects of HER administration to syngeneic recipients of a transplanted primary bladder cancer were examined. No effects on neoplastic development were observed as the result of HER treatment before and during carcinogen administration. However, at the 1-year sacrifice, there was a significant increase in bladder tumor incidence in the animals receiving BBN followed by continuous retinoid treatment versus animals receiving BBN only. At the 2-year sacrifice, there was a significant increase in tumor progression in the continuous retinoid group versus the animals receiving BBN alone, based upon grading and staging of tumors, although tumor incidences were not significantly different. In the transplantation experiment, more recipients (9/20 versus 2/20) receiving continuous HER had large, anaplastic tumors following 9 months of observation than did control animals. This study supports the view that retinoids should not be considered as only inhibitors of carcinogenesis, but rather as modifiers which vary in their effects depending upon factors yet to be understood.

Shope papillomavirus transcription in benign and malignant rabbit tumors.

Shope papillomavirus induced benign and malignant tumors from both wild and domestic rabbits were analyzed by the Northern blotting technique for the presence of viral-specific RNAs. Virus-producing benign tumors of wild cottontail rabbits are shown to contain two major RNA species approximately 5000 and 3000 bases in length that originate in the early region and include the majority of the L1 and L2 late open reading frames. Non-productive tumors including wild-rabbit carcinomas, and benign warts and primary and metastatic carcinomas of domestic rabbits uniformly are shown to contain two major viral-specific RNA species, 2400 and 1400 bases in length. These transcripts map entirely within the early region of the viral genome. In addition, Southern blot analysis of metastatic tumors indicates that the viral DNA remains exclusively extrachromosomal and apparently unrearranged supporting previous findings with epithelial malignancies.

Synergy between adjuvant arthritis and collagen-induced arthritis in rats.

Adjuvant arthritis (AA) in rats is susceptible to cell-mediated passive transfer. Collagen-induced arthritis (CIA) in rats is susceptible to passive transfer with antibody to type II collagen. We report here the development of strikingly severe arthritis in Lewis rats as the result of synergy between passively transferred antibody to type II collagen from rats with CIA and concanavalin A (Con A)-stimulated lymph node or spleen cells from syngeneic rats with AA. Similar synergy was seen in rats with AA given anticollagen antibody, in rats with CIA given Con A-stimulated adjuvant spleen cells, and in rats actively immunized with CII and complete Freund's adjuvant. The synergistic process caused a very severe polyarthritis, characterized by marked swelling and erythema in all the joints of the distal extremities, with histologic and radiographic evidence of early, extensive erosion of articular cartilage. Synergy was apparent if the lymphoid cells from AA rats were given up to 1 mo after a single injection of anticollagen antibody. No synergy was seen when normal rat immunoglobulin or anti-ovalbumin antibody was substituted for anticollagen antibody, when Con A-stimulated lymphoid cells from normal rats or donors with CIA were used, or when Con A-stimulated AA lymphoid cells were irradiated before transfer. Synergy between separate immune effector mechanisms may represent a general phenomenon in the pathogenesis of inflammatory joint disease.

Experimental and naturally-occurring gastric foreign bodies in laboratory rabbits.

Gastric foreign bodies were induced in laboratory rabbits by orogastric infusion of a liquid latex containing radiopaque dye which polymerizes in the acid environment within the stomach to form a solid mass. The rabbits were monitored clinically and radiographically for 6 months at which time gastrotomies were performed to remove the masses, followed by a 4-week observation period. None of the 14 rabbits became ill or anorectic during the 6-month period of clinical monitoring, and all gained weight. At gastrotomy, eight rabbits had both latex bezoars and trichobezoars . Though two rabbits died post-operatively from respiratory complications, the remaining 12 rabbits recovered without complications and regained their pre-operative body weight within 4 weeks. Five of 10 rabbits necropsied 1 month after gastrotomy had gastric trichobezoars . This led to a survey of the stomachs of 208 healthy slaughter-rabbits which revealed that 48 (23.1%) had trichobezoars weighing 1 to 24 g. The data suggested that gastric trichobezoars were common in rabbits and that few animals with these foreign bodies developed chronic anorexia. In addition, there appeared to be a high likelihood that trichobezoars recur in a high percentage of rabbits within several weeks postoperatively.

Detection of early changes in androgen-induced mouse renal beta-glucuronidase messenger ribonucleic acid using cloned complementary deoxyribonucleic acid.

beta-Glucuronidase mRNA was purified from androgen-induced mouse kidney by immunoadsorption of polysomes to protein A-Sepharose. Cell-free translation of mRNA isolated from the protein A bound RNA followed by immunoprecipitation revealed that beta-glucuronidase mRNA represented approximately 2% of the purified mRNA fraction. This mRNA preparation was used to produce complementary DNA clones by recombination with pBR322. Clones containing sequences that were enriched during the purification procedure were selected by differential colony hybridization. These were further screened for homology with beta-glucuronidase mRNA by hybrid-selected translation. A beta-glucuronidase cDNA clone, designated pGUS7, was identified by these criteria. With this plasmid, the abundance of beta-glucuronidase mRNA in total poly(A) mRNA from androgen-induced mouse kidney was estimated to be less than 0.04%. The beta-glucuronidase cDNA plasmid hybridized to a mRNA of 2.6 kb in length, which was induced in an androgen receptor dependent fashion over a time course of 21 days. Treatment of female mice with a single dose of testosterone (10 mg) revealed that beta-glucuronidase mRNA concentration begins to increase between 12 and 24 h after hormone administration.

Rat-bite fever in animal research laboratory personnel.

A laboratory animal technician experienced undulating fever, chills, and myalgia 3 days after he was bitten by a laboratory rat. The clinical symptoms subsided with antibiotic therapy, but recurrent fever, malaise, and joint pain occurred when therapy was discontinued. Streptobacillus moniliformis was cultured from the patient's blood.

Immune complex glomerulonephritis in baboons (Papio cynocephalus) with indwelling intravascular catheters.

Baboons with long term, indwelling, intravascular catheters developed clinical signs of renal and hepatic impairment. These included proteinuria and hypoalbuminemia without edema, and albumin to globulin ratios were reversed. Serum IgM, IgG, rheumatoid factor, and liver enzyme concentrations were above normal. Immunofluorescent staining of renal glomerular capillary loops was positive for IgG, IgM, B1c, and C4. Major microscopic lesions were membranoproliferative glomerulonephritis, chronic active hepatitis, degenerative arthritis, and chronic sialoadenitis. Electron microscopy of renal glomeruli demonstrated dense deposits in a variety of locations, mesangial cell interpositioning, and foot process fusion. These alterations, found in conjunction with the isolation of Staphylococcus aureus from the blood of affected baboons as well as the intravascular catheters, suggested that chronic bacterial infection was important in the pathogenesis of this disease.