ABSTRACT
Two transgenic rabbits (TRI and TRIII) that carried cottontail rabbit papillomavirus (CRPV) DNA alone were identified; another (TRII) carried both CRPV DNA and EJ-ras. TRI and TRIII developed extensive skin papillomas at about 1 month of age, and transcripts of CRPV DNA were detectable only in skin and/or papillomas. TRII developed extensive squamous carcinomas of the skin at a very early age. Transcription of both CRPV DNA and EJ-ras was found in the skin cancers. Thus, the tissue specificity of CRPV DNA expression in transgenic rabbits was the same as in virion-infected animals. The expression of EJ-ras could be dependent on the expression of certain CRPV genes and may be a critical cofactor of CRPV DNA in the progression of carcinomas.
Subject(s)
Animals, Genetically Modified/genetics , Cottontail rabbit papillomavirus/genetics , Genes, Viral/genetics , Genes, ras/genetics , Rabbits/genetics , Skin/pathology , Animals , Animals, Genetically Modified/anatomy & histology , Carcinoma/genetics , DNA, Neoplasm/genetics , Papilloma/genetics , Rabbits/anatomy & histology , Tissue Distribution , Transcription, GeneticABSTRACT
The common bovine papilloma virus type 1 has been widely used to stimulate basic research on papilloma viruses involved in some cancers of mankind. The usually benign neoplasms of cattle caused by bovine papilloma viruses are frequent clinical problems for veterinarians. Approximately 240 experimentally induced cutaneous fibropapillomas on 8 susceptible calves had a uniform appearance of initial growth. Their size and duration ranged from about 2 months to nearly 3 years but were similar for the multiple papillomas of each calf. Sequential biopsies were done to examine the histologic changes and existence of viral antigen. Veterinarians in practice may encounter the common fibropapillomas caused by bovine papilloma virus 1 and 2 as well as papillomas with no fibromatous element. These types may develop on teats of cows in some herds. Interdigital papillomas cause a problem in some dairy herds and a virus suspected but not yet found. Prophylactic vaccination with a formalin-killed vaccine will protect against infection with bovine papilloma virus 1 and 2.
Subject(s)
Cattle Diseases/pathology , Papillomaviridae , Tumor Virus Infections/veterinary , Animals , Cattle , Male , Tumor Virus Infections/pathologyABSTRACT
The acyclic nucleotide PMEG was studied for effectiveness against Shope papillomavirus (CRPV) infection of rabbits and human papillomavirus type 11 (HPV-11) infections of human foreskin xenografts in athymic mice. PMEG given in the latent period strongly suppressed the subsequent growth rates of Shope papillomas. PMEG starting in the latent period and continuing for the duration of the experiment, inhibited HPV-11 infections of human skin, including condyloma growth, and synthesis of viral DNA and capsid antigen. Drug toxicity paralleled the therapeutic effects in rabbits but there was much less toxicity in athymic mice.
Subject(s)
Antineoplastic Agents/therapeutic use , Antiviral Agents/therapeutic use , Guanine/analogs & derivatives , Organophosphorus Compounds/therapeutic use , Papillomaviridae/drug effects , Tumor Virus Infections/drug therapy , Animals , Antigens, Viral/immunology , Capsid/immunology , DNA, Viral/biosynthesis , Female , Guanine/therapeutic use , Humans , Male , Papillomaviridae/genetics , Papillomaviridae/growth & development , RabbitsABSTRACT
A 4th of 667 cattle examined at a Wisconsin abattoir had teat papillomas. Excised teat papillomas were sorted by gross morphologic characteristics into 3 groups: (i) atypical filiform, (ii) atypical flat, and (iii) typical fibropapilloma. Bovine papilloma virus capsid antigen was detected in thin-section slides of the 3 groups of teat papillomas by peroxidase-antiperoxidase assay. The bovine papilloma virus involved with the atypical papillomas could not be characterized by molecular hybridization, because enough pure virus could not be harvested. Homogenates of the 3 groups of teat papillomas were inoculated on 2 ponies and 4 calves. Typical fibropapillomas were produced on the 4 calves, and fibromas, on the 2 ponies. Atypical papillomas were produced only in 2 heifers.
Subject(s)
Cattle Diseases/epidemiology , Mammary Glands, Animal , Neoplasms/veterinary , Papilloma/veterinary , Abattoirs , Animals , Antigens, Viral/analysis , Bovine papillomavirus 1/immunology , Cattle , Female , Immunoenzyme Techniques , Papilloma/epidemiology , WisconsinABSTRACT
The cesarean section rate has been rising in California since 1965. In this article, we describe the trend in cesarean section rates in California from 1960 to 1975 in relation to maternal and infant variables. Approximately proportionate increases in cesarean section rates by infant birth weight and maternal race were found. Cesarean section rates for women under 20 years of age and for those of first parity have risen proportionately more than rates for other age and parity groups. We also found that cesarean section rates for births at gestational age's exceeding 42 weeks have risen proportionately more than rates for births at other gestational ages. Maternal mortality ratios associated with cesarean section were twice those associated with noncesarean births for the years 1973, 1974, and 1975. Possible explanations of the current cesarean section rate include an increase in indications for the procedure, use of the fetal monitor, and the current medical-legal climate. The potential problems that cesarean section may create for the mother and infant are higher rates of iatrogenic prematurity and respiratory distress and of maternal morbidity and mortality.
