Abstract. Spontaneous enteric disease characterized by hemorrhagic diarrhea and high mortality occurred in puppies from commercial kennels in three midwestern states. Microscopic lesions resembling those of panleukopenia in cats were seen in the intestines. The predominant features were necrosis of crypt epithelium, collapse or dilation of crypt lumina and villous atrophy. Viral particles morphologically resembling parvovirus were found in the feces by direct electron microscopy. The canine virus reacted with antibody to feline panleukopenia virus by immunoelectron microscopy and fluorescent antibody technique. Fluorescent antibody was used to detect virus in the crypt epithelium of affected dogs. Feline kidney cells inoculated with fecal preparations had cytopathic effect and positive fluorescence by fluorescent antibody technique.Widespread outbreaks of severe enteric disease associated with a parvovirus-like agent occurred in dogs throughout the United States and Canada in 1978 [2, 5, 7, 191. Although a parvovirus was isolated from asymptomatic dogs in 1970 [6], the first association of parvovirus with canine diarrhea was made in 1977 (81.Intestinal infections with parvovirus have been associated with enteric disease in cats [lo, 121 and calves [l, 3, 171. Feline panleukopenia is caused by a parvovirus, and the distinctive histologic lesions are attributed to the requirement for rapidly dividing cells for viral replication [l 1, 141. Infected cells must proceed through the DNA synthesis phase of the cell cycle before replication of the parvovirus can occur [9, 11,16, 181. The canine enteric disease seems to bear more than superficial resemblance to feline panleukopenia. Leukopenia is a common feature in affected dogs, and the enteritis is characterized by involvement of the intestinal crypts (2, 5, Materials and MethodsThe material for this study was from five dogs submitted for necropsy and specimens of formalin-ftxed and refrigerated tissues from five additional dogs. Tissues for histologic evaluation were ftxed in neutral buffered to% formalin and routinely processed. Paraffmembedded sections were cut at 7 micrometers and stained with hematoxylin and eosin (HE).Intestinal contents were collected from seven dogs from which fresh or refrigerated viscera were available. The samples were prepared for negative contrast electron microscopy as described (41. For immunoelectron microscopy three drops of the fecal preparation were mixed with three drops of feline panleukopenia virus antiserum and incubated overnight at 4OC. 68071.
The purpose of this study was to determine whether sows shed rotavirus near the time of farrowing. Twelve sows purchased from a common source and seropositive for rotavirus were housed in isolation in farrowing crates from 5 days before to 3 weeks after farrowing. Fecal samples were collected at 3- to 4-day intervals and examined for the presence of rotavirus by direct electron microscopy. Samples were also treated with pancreatin and inoculated onto monkey kidney cells. Rotaviral antigens were detected by a direct immunofluorescence technique, and selected positive cultures were examined by immunoelectron microscopy. Rotavirus was detected in the feces of 5 of 12 sows as early as 5 days before to 2 weeks after farrowing. Diarrhea related to rotavirus developed in 4 of 12 litters. Two of these four litters were farrowed by sows which shed rotavirus at 7 and 10 and 14 days after farrowing. The results of this study indicate that sows immune to rotavirus can shed virus in their feces at a time when piglets are particularly susceptible to infection and that adult swine are of primary importance in the epidemiology of rotavirus as initiators of infection.
Discussed is the XENIX"' Operating System for the IBM Personal Computer AT. The operating system lncorpo• rates capabilities of a mainframe operating system multlusage, multitasking, file management and secu• rlty, program compilation, and networking. The XENIX shell structure Is Introduced. Pipes and pipellning are presented. The XENIX file structure is explained and illustrated with examples. Software development and text formatting are treated in detail. The ability to com pile C program code developed under XENIX and run It on the IBM Personal Computer Disk Operating System is explained. T his paper describes the IBM Personal Computer XENIX Operating System and options. {XENIX is a trademark of the Microsoft Corporation.) Dis cussed are the basic features of the XENIX Operating System, primarily for users who are new to UNIX, and enhancements of IBM Personal Computer XENIX. Since the first announcement of personal computers, users have sought operating systems to help them increase productivity. The XENIX system brings many of the features normally found on mainframe computers to the IBM Personal Computer AT. The IBM Personal Computer XENIX, developed in con junction with the Microsoft Corporation, is an en hanced version of the UNIX Operating System origi nally developed at Bell Laboratories. (UNIX is a trade mark of the AT&T Bell Telephone Laboratories, Inc.) The movement toward UNIX has resulted from its versatility and from the portability of its programs to compatible systems.
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