Strontium-90: effects of chronic ingestion on farrowing performance of miniature swine.

In experiments involving the ingestion of strontium-90 by nearly 800 female miniature swine and extending over three generations, no significant differences in litter size, percentage of stillborn, or birth weight were observed between controls and animals ingesting up to 625 microcuries of strontium-90 per day. At 625 microcuries per day, these animals were ingesting more than a million times the peak value of strontium-90 ever reported in the American diet. Animals on 3100 microcuries per day did not survive the gestation period. From these studies, it is evident that feeding levels of strontium-90 high enough to affect fetal or neonatal mortality in this species will not permit maternal survival long enough for the bearing of young.

Cyclosporine and skin allografts for the treatment of thermal injury. I. Extensive graft survival with low-level long-term administration and prolongation in a rat burn model.

The hypothesis tested in the present and accompanying study is that an effective treatment for severe burns involves early excision of necrotic tissue followed by skin allografting and cyclosporine (CsA) immunosuppressive therapy. LEW (RT1) rats served as recipients of thermal injury and/or skin allografts. BN x LEW F1 (LBN, RT1(l+n)) rats served as skin donors. LEW burn recipients received a hot water (90 degrees C for 10 sec) 30% body surface area (BSA) full-thickness burn. As expected, LEW recipients treated with CsA (25 mg/kg/day for 20 days) demonstrated significant graft prolongation compared with controls (P less than 0.005). Skin graft survival was similarly prolonged in LEW recipients undergoing burn injury, primary wound excision, and CsA administration compared with burn-skin allograft controls (P less than 0.001). Mortality was not increased in the thermal injury-CsA-treated recipients compared with burn controls. A final experiment was initiated to investigate how low-level long-term (greater than 100 days) maintenance CsA treatment influenced skin allograft survival for possible future consideration in burn trauma. Recipients receiving skin allografts plus CsA (20 days, 8mg/kg/day, followed by every other day thereafter) did not reject their grafts. However, a possible early sign of rejection (a single small ulcerative lesion) was noted in five of these long-term CsA-treated animals at a mean of 34 +/- 11 (SD) days. The lesion in these animals did not progress any further during CsA administration. Histopathologic study of selected animals removed from the CsA maintenance regimen for greater than 50 days following long-term administration revealed a number of interesting chronic lesions similar to those previously reported in the skin component of composite tissue (limb) allografts following long-term low-level CsA intervention. In conclusion, CsA was very successful in preventing rejection of skin allografts in a rat burn model without apparent adverse effects.

Composite tissue (limb) allografts in rats. I. Dose-dependent increase in survival with cyclosporine.

The dose-response effect of cyclosporine on rat limb transplant prolongation was investigated across the LBN-to-LEW histocompatibility barrier. This composite tissue allograft model has been shown to represent a strong transplantation barrier. Median limb allograft survival times increased in a dose-dependent manner with low cyclosporine doses, and then reached a plateau at higher levels. The cyclosporine dose that produced half-maximal survival based on a 20-day treatment was only 3.7 mg/kg/day. Histopathology revealed that the rejection process was distinctly different in limb allografts treated with cyclosporine compared with non-cyclosporine-treated controls. Rejection appeared to be delayed or partly arrested in certain areas of cyclosporine-treated limb allografts. These studies represent an initial step in laying the experimental foundation for clinical transplantation of composite tissue allografts using cyclosporine-induced immune suppression.

Composite tissue (limb) allografts in rats. II. Indefinite survival using low-dose cyclosporine.

Cyclosporine has reawakened interest in transplantation of peripheral composite tissue allografts (CTA) of skin, muscle, bone, vessel, and nerves. The purpose of this study was to examine whether cyclosporine could produce indefinite survival of CTA. Two groups of LEW recipients of LBN limb transplants were given different long-term treatments of cyclosporine. Tolerance was achieved in many of the animals. Several possibilities for the mechanism of this tolerance are discussed.

Composite tissue (limb) allografts in rats. III. Development of donor-host lymphoid chimeras in long-term survivors.

Eight LEW rat recipients possessing long-term-surviving (206-701 days) LBN vascularized hind limb allografts (CTAs) were tested for donor-host lymphoid chimerism. The recipients received various cyclosporine (CsA) treatment protocols in order to induce indefinite CTA acceptance. Histological examination of long-term-surviving CTAs demonstrated normal-appearing bone marrow in the donor limb. Lymphocytes isolated from host hemopoietic tissues (peripheral blood and/or spleen) by ficoll-hypaque density gradient centrifugation were tested against LEW-anti-BN antisera. Comparisons were made to standard curves employing various known concentrations of LBN and LEW cell combinations. The level of lymphocyte agglutination (dependent variable) showed a significant (P less than 0.025-0.005) linear relationship to the concentration of LBN donor cells (independent variable) present. Lymphocyte suspensions isolated from long-term CTA host peripheral blood and/or spleen showed a mean of 19.7% (+/- 9.7-95% confidence interval) donor LBN mononuclear cells present. Thus, it appeared that lymphoid cells originated from, and/or were released from LBN donor bone marrow into the circulation, resulting in chimeric repopulation of hemopoietic tissues. The presence of donor immunocytes in these limb allograft recipients may have been beneficial, and thus could have helped contribute to the long-term CTA survival observed.

Urinary tract infection after injection of pseudomonas into bladder.

Pseudomonas urinary tract infection was studied in female mice. The bladder was exposed by a lower midline incision and an overnight washed culture of Pseudomonas (0.05 ml.) was injected into the bladder. This resulted in infection of the kidneys in more than 50 per cent of mice at one week. At four hours, the microulceration of the bladder was observed with many Pseudomonas int the base of the ulcer. The presence of acute inflammation on the serosal surface of the bladder, the frequent death of the mice, the presence of cortical foci of polymorphonuclear leukocytes in the kidneys, and bacteremia suggested that bacteremia may play a significant role in the development of the renal infection in this model of urinary tract infection. Bacteria injected through the bladder wall of mice cannot be assumed to produce ascending infection of the kidney.

Nonmucinous nature of the surface material of the bladder mucosa.

The urinary bladder is lined by transitional epithelium, also known as urothelium. Some investigators have described a material known as mucin, which lines the luminal surface of the urothelium, but its nature is not well understood. The authors examined sections of bladder from rat, mouse, rabbit, and man and found that, although they reacted differently to common histochemical stains for complex carbohydrates, none showed any material that stained as mucin on the surface of the mucosa. Rather, intracellular granules that have varying staining characteristics in different animals were found on the luminal side of the urothelium. The authors speculate, based on their histochemical findings, that some form of mucin may be present in the urothelial granules in man and that studies on animals may not be applicable to man.

Malignant lymphoma of the meninges in two dogs.

Two cases of malignant lymphoma of the leptomeninges in dogs are described. Both involved the subarachnoid space overlying the cerebrum and cerebellum and in one dog there was infiltration of neoplastic lymphocytes into the leptomeninges of the cervical spinal cord and nerve roots. These cases appeared to represent primary meningeal lymphoma, except that lymphoma was present in an ovary of one of the dogs and here the meningeal lymphocytes were demonstrated to be B cells by the peroxidase-antiperoxidase method for cytoplasmic immunoglobulin. Meningeal lymphoma, primary or metastic, is rare in dogs. The differential diagnosis is discussed and includes reticulosis, sarcomatosis of the meninges, and the diffuse spread of an oligodendroglioma in the subarachnoid space. A tentative diagnosis of meningeal lymphoma in these cases could be made by examination of the cerebrospinal fluid cells.

Canine bladder epithelial cells in culture: susceptibility to canine distemper and measles viruses.

A canine bladder epithelial cell strain was established in culture for the study of canine distemper virus. Epithelial cells were scraped off the bladder with a scalpel and were cultured in enriched Eagle's medium. Cells were enzymatically dispersed and passed over 46 population doublings which covered a period of more than 3 years. The cells were heteroploid when karyotyped at passage level 5 and 42. This cell strain permitted direct isolation of canine distemper virus and also showed susceptibility to laboratory strains of measles virus. Seemingly, establishment of cell strains from canine bladder epithelium can be accomplished without difficulty.

Epidemiologic and pathologic aspects of an epizootic of malignant catarrhal fever in exotic hoofstock.

An epizootic of malignant catarrhal fever (MCF) occurred at the Los Angeles Zoological Park which resulted in the deaths of four exotic ungulates. The source of infection was considered to be a newly purchased wildebeest bull (Connochaetes taurinus taurinus) that had been negative for antibody to MCF virus by an indirect immunofluorescent test. The need to re-evaluate regulations for the transportation and housing of young wildebeest is emphasized by this MCF outbreak. The diagnostic technology now available for identifying asymptomatic carriers of MCF virus and the present understanding of the behavior and pathogenesis of this highly cell-associated herpesvirus in exotic ruminants should provide a basis for the prevention and control of MCF in zoological parks.

Acute viral hepatitis in California sea lions.

Acute viral hepatitis was diagnosed in five California sea lions (Zalophus californianus) stranded along the Los Angeles coast. Light microscopy revealed large nuclear inclusion bodies in hepatocytes. Electron microscopy provided evidence that these inclusion bodies were composed of adenovirus-like virions. Attempts to grow the virus in cell culture systems were unsuccessful.

Hepatic and gastric amebiasis in black and white colobus monkeys.

Three cases of hepatic amebiasis and one case of gastric amebiasis were diagnosed in black and white colobus monkeys during a 9-month period. The diagnosis was difficult because of the absence of trophozoites and cysts in the feces and because of few trophozoites found in many of the hepatic lesions. Indirect hemagglutination titers were diagnostic in 2 monkeys.

Pulmonary tuberculosis in a sulfur-crested cockatoo.

An adult, female sulfur-crested cockatoo (Kakatoe sp) was examined because of dyspnea associated with hemoptysis. On radiographic examination there was a large cystic pulmonary mass that, on aspiration, was found to contain thick sanguineous fluid. Ziehl-Neelsen staining of aspirate smears revealed numerous acid-fast organisms. Gross necropsy and microscopic findings suggested a diagnosis of tuberculosis, with primary focus of infection in the pulmonary tissues. Bacteriologic isolation and typing confirmed a diagnosis of tuberculosis and established Mycobacterium avium as the etiologic agent.