Changes in the leukocyte phenotype profile of goats infected with the caprine arthritis encephalitis virus.

The proportions of different sub-populations of leukocytes in five healthy goats and five goats infected with the caprine arthritis encephalitis virus (CAEV) were examined using immunofluorescence and flow cytometry. A panel of monoclonal antibodies that identified a monocytegranulocyte marker (GMI); the CD4, CD8, IgM, MHC Class I, MHC Class II and T19 antigens, and the gamma delta (gamma delta) T cell receptor was used. We observed a significant (P = 0.016) reduction in the proportion of monocytes in the peripheral blood of infected (5.98%) compared with healthy control goats (9.92%). There was also a decrease in the proportion of CD4+ T lymphocytes that approached significance (P = 0.076) accompanied by a slight increase in the proportion of CD8+ T lymphocytes, in infected compared with uninfected animals. Consequently, three of the five infected animals had lower CD4:CD8 ratios than any of the healthy animals and two of these three ratios were inverted. Approximately 14% of T cells in the peripheral blood of healthy goats was identified as gamma delta T cells and all expressed the T19 antigen. A significantly elevated level of gamma delta T cells (P = 0.030) and an elevated level of T19 cells were observed in infected, compared with healthy animals. The proportion of leukocytes expressing surface IgM (B cells) was also elevated, although not significantly, in CAEV-infected compared to healthy controls. The changes in peripheral blood leukocyte subsets in infected goats suggest that immune responses to the infection are probably altered in these animals with eventual progression to severe disease and death.

Detection of caprine arthritis-encephalitis virus by polymerase chain reaction.

Detection of caprine arthritis-encephalitis virus (CAEV) infection in goats is currently limited to serologic testing or cell culture. We developed a polymerase chain reaction (PCR) assay to detect CAEV sequences in peripheral blood mononuclear cells (PBMC), synovial fluid cells (SFC), and milk cells (MC) obtained from infected goats. Results were positive for 18 of 20 PBMC, 8 of 8 MC, and 5 of 5 SFC samples from seropositive goats, whereas 3 of 33 PBMC samples and none of 8 MC or 5 SFC samples from seronegative goats were positive. Two of the PCR-positive and seronegative goats seroconverted upon follow-up testing 2 months later. This PCR assay provides a useful method for detecting CAEV infection in goats.

Effects of microgravity or simulated launch on testicular function in rats.

Testes from flight rats on COSMOS 2044 and simulated-launch, vivarium, or caudal-elevation control rats (5/group) were analyzed by subjective and quantitative methods. On the basis of observations of fixed tissue, it was evident that some rats had testicular abnormalities unassociated with treatment and probably existing when they were assigned randomly to the four treatment groups. Considering rats without preexisting abnormalities, diameter of seminiferous tubules and numbers of germ cells per tubule cross section were lower (P less than 0.05) in flight than in simulated-launch or vivarium rats. However, ratios of germ cells to each other or to Sertoli cells and number of homogenization-resistant spermatids did not differ from values for simulated-launch or vivarium controls. Expression of testis-specific gene products was not greatly altered by flight. Furthermore, there was no evidence for production of stress-inducible transcripts of the hsp70 or hsp90 genes. Concentration of receptors for rat luteinizing hormone in testicular tissue and surface density of smooth endoplasmic reticulum in Leydig cells were similar in flight and simulated-launch rats. However, concentrations of testosterone in testicular tissue or peripheral blood plasma were reduced (P less than 0.05) in flight rats to less than 20% of values for simulated-launch or vivarium controls. Thus spermatogenesis was essentially normal in flight rats, but production of testosterone was severely depressed. Exposure to microgravity for greater than 2 wk might result in additional changes. Sequelae of reduced androgen production associated with microgravity on turnover of muscle and bone should be considered.

Comparative study of spermatogonial survival after x-ray exposure, high LET (HZE) irradiation or spaceflight.

Spermatogonial cell loss has been observed in rats flown on Space Lab 3, Cosmos 1887, Cosmos 2044 and in mice following irradiation with X-ray or with high energy (HZE) particle beams. Spermatogonial loss is determined by cell counting in maturation stage 6 seminiferous [correction of seminferous] tubules. With the exception of Iron, laboratory irradiation experiments (with mice) revealed a similar pattern of spermatogonial loss proportional to the radiation dose at levels less than 0.1 Gy. Helium and Argon irradiation resulted in a 5% loss of spermatogonia after only 0.01 Gy exposure. However, significant spermatogonial loss (45%) occured at this radiation level with Iron particle beams. The loss of spermatogonia during each space flight was less than 10% when compared to control (non-flight) animals. This loss, although small, was significant. Although radiation may be a contributing factor in the loss of spermatogonia during space flight, exposure levels, as determined by dosimetry, were not significant to account for the total cell loss observed.

Effects of spaceflight on the spermatogonial population of rat seminiferous epithelium.

Testes from rats flown on Cosmos 1887 were compared with vivarium control and synchronous control samples. The mean weights of flight testes, normalized for weight per 100 g, were 6.4% less when compared with the vivarium controls. Counts of spermatogonia from tissue sections (seminiferous tubules in maturation stage 6) from five animals in each group revealed 4% fewer spermatogonia in flight testes compared with synchronous controls and 11% fewer spermatogonia in flight samples compared with vivarium controls.

Morphological and biochemical examination of Cosmos 1887 rat heart tissue: Part I--Ultrastructure.

Morphological changes were observed in the left ventricle of rat heart tissue from animals flown on the Cosmos 1887 biosatellite for 12.5 days. These tissues were compared to the synchronous and vivarium control hearts. While many normal myofibrils were observed, others exhibited ultrastructural alterations, i.e., damaged and irregular-shaped mitochondria and generalized myofibrillar edema. Analysis of variance (ANOVA) of the volume density data revealed a statistically significant increase in glycogen and a significant decrease in mitochondria compared to the synchronous and vivarium controls. Point counting indicated an increase in lipid and myeloid bodies and a decrease in microtubules, but these changes were not statistically significant. In addition, the flight animals exhibited some patchy loss of protofibrils (actin and myosin filaments) and some abnormal supercontracted myofibrils that were not seen in the controls. This study was undertaken to gain insight into the mechanistic aspects of cardiac changes in both animals and human beings as a consequence of space travel (1). Cardiac hypotrophy and fluid shifts have been observed after actual or simulated weightlessness and raise concerns about the functioning of the heart and circulatory system during and after travel in space (2-4).

The distribution of C-bands in canine transmissible venereal tumor cells.

Colchicine-arrested metaphase preparations, derived from canine transmissible venereal tumor (TVT) cells grown in culture, were characterized based on the occurrence and distribution of constitutive heterochromatin. Analysis of the data with regard to the distribution of C-bands in the pericentric, interstitial and telomeric segments revealed a nonrandom distribution along the arms of many chromosomes with the bulk of the bands occurring in the centromeric region. The frequency of C-banded regions differed from those reported for normal dog cells and both primary and transplanted tumors. These results suggest that similar nondifferentially-stained TVT karyotypes do not necessarily exhibit identical distribution of constitutive heterochromatin.

The effect of high energy (HZE) particle radiation (40Ar) on aging parameters of mouse hippocampus and retina.

Eight month old C57BL6 mice were exposed (head only) to 0.5 rad or 50 rads of Argon particles at the Lawrence Berkeley Radiation Facility, CA. Neuromotor performance was assessed monthly for six months beginning twelve weeks post-irradiation using a "string test". The decline in motor performance was dose-related and none of the animals was able to complete the task after four months of testing. Morphological changes were monitored six and twelve months post-irradiation by light and electron microscopy. The synaptic density in the CA-1 area of the hippocampus decreased six and twelve months after irradiation. The decrease after twelve months was less than after six months. The width of the outer nuclear layer (ONL) of the retina increased with increasing dose. The number of blood vessels between the ONL and the ganglion layer decreased twelve months after irradiation and this area did not show significant accumulation of age pigment.

Response of the seminiferous epithelium of the mouse exposed to low dose high energy (HZE) and electromagnetic radiation.

This study was undertaken to observe the response of a rapidly dividing cell population (spermatogonial) to Helium and Argon ions as compared to x-rays. Low doses (below 100 rads) were used to more nearly simulate radiation encountered during space missions. The methods used proved compatible for both light and electron microscope studies. The average relative biological effectiveness (RBE) for Helium ions is 1, while Argon is twice as effective in killing spermatogonial cells. Part of this mixed population of cells exhibits a higher sensitivity to radiation below 15 rads. Quantitation of the radiation effects by counting the necrotic cells is not feasible because of their rapid removal, therefore all measurements were done using the surviving fraction (S/So) of spermatogonial cells.

Cytogenetic observations on the canine venereal tumor in long-term culture.

Cytogenetic observations are reported on five canine venereal tumor tissue culture cell lines maintained over periods of 13 to 30 months. In all instances, a karyotype was observed that is strikingly similar to those reported elsewhere for spontaneous or transplanted venereal tumors. The modal number in all lines was close to 59, containing 17 to 19 abnormal metacentric chromosomes. Three of the metacentric chromosomes were identified as markers. Assays for oncogenic properties were undertake in heterologous and homologous hosts. Attempts to induce tumor formation in homologous hosts using the cultured venereal tumor cell were uniformly unsuccessful.

Studies on the kidneys of pregnant hamsters infected with Leptospira canicola.

An electron microscopic study on the histopathological changes in the kidneys of pregnant hamsters resulting from infection with Leptospira canicola was undertaken. The experiment revealed damage to the glomeruli as well as the tubules. The severity of these lesions increased with the progress of the disease and examination of kidney sections showed leptospires in the tissue. It is suggested that the stress of pregnancy has some influence on the severity of the lesions seen in this disease.

Histopathologic evaluation of livers of pregnant hamsters infected with Leptospira canicola.

Pregnant hamsters were inoculated with Leptospira canicola by an intraperitoneal route. Grossly, the livers were enlarged and pale yellow. On light microscopic examination, disruption of the hepatic cords, as well as granulation of hepatocyte cytoplasm, was evident. On electron microscopic examination, the livers had evidence of severe cellular degradation as early as post-inoculation hour (PIH) 24. At PIH 96, pathologic changes were more pronounced. The rough endoplasmic reticulum was swollen and there was membrane disruption. These changes were not observed in the livers of control animals. In addition, livers of the fetuses at PIH 72 exhibited severe degenerative changes.

Light and electron microscopic study of the livers of pregnant mice infected with Listeria monocytogenes.

Listeria monocytogenes cells were observed in the hepatic cell cytoplasm or in the phagosome at 24 and 48 hours but not at 72 hours after inoculation in pregnant mice. The presence of bacteria initially in a membrane-bound vesicle indicates that the bacteria enter the hepatic cells by endocytosis, resulting in eventual destruction of hepatic cells. Characteristic lesions of the liver at 24 and 48 hours after inoculation consist of multiple focal areas of necrosis. The initial neutrophilic reaction seems to give way to a mononuclear reaction (listeriomas) at 72 hours after inoculation. Dilation of rough endoplasmic reticulum and release of many of the bound ribosomes with a relative increase in the number of free ribosomes was observed. Hepatic lesions were not observed in control (nonpregnant) mice.

Cosmic ray effects on the eyes of rats flown on Cosmos No. 782, experimental K-007.

The eyes from six rats were fixed at the recovery site in Russia after they had circled the earth for 19.5 d in a 62.8 degree orbit. The eyes of six more flight rats were fixed 25 d later. These two preparations and eyes exposed to 1000 rad of neon and argon were compared to obtain data on possible radiation effects on the retina. Most of the flight eye tissue was normal; however, necrotic nuclei were found in the outer nuclear layer and channels were located in the outer segment area. Macrophages were seen between the pigment layer and outer segments. Comparison of the Day zero znd 25-d postflight eyes suggested some possible recovery. Light flashes seen by space travelers and damage from cosmic rays appear to arise from two different sites of interaction. The flashes are created by cosmic ray transversal of the outer segments while pathologic change, when it occurs, is quite possibly from interaction with some part of the nucleus. Nevertheless, direct interaction with other cellular components could also occur. Other factors, such as secondaries from spacecraft shielding, may play an important role.