Characterization of orally efficacious influenza drug with high resistance barrier in ferrets and human airway epithelia

Influenza viruses constitute a major health threat and economic burden globally, frequently exacerbated by preexisting or rapidly emerging resistance to antiviral therapeutics. To address the unmet need of improved influenza therapy, we have created EIDD-2801, an isopropylester prodrug of the ribonucleoside analog N ⁴-hydroxycytidine (NHC, EIDD-1931) that has shown broad anti-influenza virus activity in cultured cells and mice. Pharmacokinetic profiling demonstrated that EIDD-2801 was orally bioavailable in ferrets and nonhuman primates. Therapeutic oral dosing of influenza virus-infected ferrets reduced group pandemic 1 and group 2 seasonal influenza A shed virus load by multiple orders of magnitude and alleviated fever, airway epithelium histopathology, and inflammation, whereas postexposure prophylactic dosing was sterilizing. Deep sequencing highlighted lethal viral mutagenesis as the underlying mechanism of activity and revealed a prohibitive barrier to the development of viral resistance. Inhibitory concentrations were low nanomolar against influenza A and B viruses in disease-relevant well-differentiated human air-liquid interface airway epithelia. Correlating antiviral efficacy and cytotoxicity thresholds with pharmacokinetic profiles in human airway epithelium models revealed a therapeutic window >1713 and established dosing parameters required for efficacious human therapy. These data recommend EIDD-2801 as a clinical candidate with high potential for monotherapy of seasonal and pandemic influenza virus infections. Our results inform EIDD-2801 clinical trial design and drug exposure targets.

The significance of galectin-3 as a new basal cell marker in prostate cancer

Prostate cancer may originate from distinct cell types, resulting in the heterogeneity of this disease. Galectin-3 (Gal-3) and androgen receptor (AR) have been reported to play important roles in the progression of prostate cancer, and their heterogeneous expressions might be associated with different cancer subtypes. Our study found that in various prostate cancer cell lines Gal-3 expression was always opposite to AR expression and other luminal cell markers but consistent with basal cell markers including glutathione S-transferase-π and Bcl-2. This expression pattern was confirmed in human prostate cancer tissues. Our results also showed that prostate cancer cells positive with basal cell markers were more aggressive. Downregulation of Gal-3 expression resulted in increased apoptotic potential and decreased metastasis potential of prostate cancer cells. Our findings demonstrate for the first time that Gal-3 may serve as a new marker for basal characteristics of prostate cancer epithelium. This study helps us to better understand the heterogeneity of prostate cancer. The clinical significance of this study lies in the application of Gal-3 to distinguish prostate cancer subtypes and improve treatment efficacy with designed personalized therapy.

Attenuation of a virulent Aeromonas hydrophila with novobiocin and pathogenic characterization of the novobiocin-resistant strain

AIM

To determine whether novobiocin resistance strategy could be used to attenuate a virulent Aeromonas hydrophila AH11P strain and to characterize the growth and pathogenic differences between the novobiocin-resistant strain and its virulent parent strain AH11P.

METHODS AND RESULTS

A novobiocin-resistant strain AH11NOVO was obtained from a virulent Aer. hydrophila strain AH11P through selection of resistance to novobiocin. AH11NOVO was found to be avirulent to channel catfish (Ictalurus punctatus), whereas AH11P was virulent. When AH11NOVO vaccinated channel catfish were challenged with AH11P at 14 days postvaccination, relative per cent of survival of vaccinated fish was 100%. The cell proliferation rate of AH11NOVO was found to be significantly (P < 0.05) less than that of AH11P. In vitro motility assay revealed that AH11NOVO was nonmotile, whereas AH11P was motile. AH11NOVO had significantly (P < 0.05) lower in vitro chemotactic response to catfish mucus than that of AH11P. Although the ability of AH11NOVO to attach catfish gill cells was similar to that of AH11P, the ability of AH11NOVO to invade catfish gill cells was significantly (P < 0.05) lower than that of AH11P.

CONCLUSIONS

The novobiocin-resistant AH11NOVO is attenuated and different from its parent AH11P in pathogenicity.

SIGNIFICANCE AND IMPACT OF THE STUDY

The significantly lower chemotactic response and invasion ability of AH11NOVO compared with that of its virulent parent strain AH11P might shed light on the pathogenesis of Aer. hydrophila.

Immunomodulation of caprine lentiviral infection by interleukin-16

Interleukin-16 (IL-16) is a proinflammatory cytokine produced by a variety of cells including lymphocytes, macrophages, mast cells, and eosinophils. We have shown in our previous studies increased expression of IL-16 mRNA and protein in caprine arthritis-encephalitis virus (CAEV)-infected goats blood. In this study, we determined the immunomodulatory effects of IL-16 in vitro using cells derived from CAEV infected and uninfected goats. Human recombinant IL-16 (rhIL-16) significantly increased chemotaxis of peripheral blood mononuclear cells (PBMCs) of both control and CAEV-infected goats. Pretreatment of PBMC with anti-goat CD4 monoclonal antibody inhibited IL-16-induced chemotaxis of PBMC of control and infected goats suggesting that IL-16 exerts its action in goats primarily by binding to CD4. The CAEV proviral DNA was less in caprine monocytes treated with rhIL-16 infected in vitro with CAEV. These data suggest inhibitory effect of IL-16 on viral integration. Flow cytometric studies indicated a trend toward IL-16-induced increased expression of lymphocyte activation markers. Combined with our previously reported data, these experiments suggest that increased IL-16 expression during CAEV infection may inhibit viral integration.

Ancestral consanguinity and mortality among three endogamous populations of Chittoor District, Andhra Pradesh, India

Consanguineous marriages have been practiced around the globe by many societies from time immemorial, particularly in South India. Consanguineous marriages play a major role in the health of a population, and diseases leading to mortality of the progeny are a consequence of detrimental recessive genes. To evaluate the effects of ancestral consanguinity on mortality in relation to consanguineous marriage, we have ascertained data from 1,500 women belonging to three endogamous communities (Akuthota Reddy, Odde, and Madiga) of Chittoor District, Andhra Pradesh, India. There were 500 women from each community. For each marriage we drew a family pedigree, extended upward to two earlier generations on either side of the spouses, to determine the prevalence and pattern of consanguinity, with detailed information on fertility and mortality. We observed a significant difference in the mortality rates between consanguineous and nonconsanguineous marriages when all the marriages of the women, women's parents, and (women's) husband's parents were considered in all three communities. In inbreeding, the offspring of earlier generations might have passed on deleterious genes to later generations (under unfavorable conditions), which resulted in a negative aspect of reproduction (among the offspring of the present couple).

Diversity and divergence among the tribal populations of India

Tribal populations of the Indian subcontinent have been of longstanding interest to anthropologists and human geneticists. To investigate the relationship of Indian tribes to Indian castes and continental populations, we analyzed 45 unlinked autosomal STR loci in 9 tribal groups, 8 castes, and 18 populations from Africa, Europe and East Asia. South Indian tribal populations demonstrate low within-population heterozygosity (range: 0.54 - 0.69), while tribal populations sampled further north and east have higher heterozygosity (range: 0.69 - 0.74). Genetic distance estimates show that tribal Indians are more closely related to caste Indians than to other major groups. Between-tribe differentiation is high and exceeds that for eight sub-Saharan African populations (4.8% vs. 3.7%). Telugu-speaking populations are less differentiated than non-Telugu speakers (F(ST): 0.029 vs. 0.079), but geographic distance was not predictive of genetic affinity between tribes. South Indian tribes show significant population structure, and individuals can be clustered statistically into groups that correspond with their tribal affiliation. These results are consistent with high levels of genetic drift and isolation in Indian tribal populations, particularly those of South India, and they imply that these populations may be potential candidates for linkage disequilibrium and association mapping.

Comparison of culture, multiplex, and 5' nuclease polymerase chain reaction assays for the rapid detection of Yersinia enterocolitica in swine and pork products

Bacteriological culture was compared with multiplex and fluorogenic (TaqMan) polymerase chain reaction (PCR) assays for the detection of attachment invasion locus (ail)-bearing Yersinia enterocolitica in market weight swine, chitterlings, and ground pork. The TaqMan assay detected 1 pg of purified Y. enterocolitica DNA, whereas conventional gel-based PCR detected I ng of the same. The presence of ail-bearing Y. enterocolitica was tested in pork and feces artificially inoculated with Y. enterocolitica strain NADC 5561. The sensitivity limits of culture, multiplex, and TaqMan PCR assays were 4 x 10(3), 4 x 10(2), and 0.4 CFU/g, respectively, for the artificially inoculated pork. The sensitivity limits were 4 x 10(2), 4 x 10(2), and 0.4 CFU/g, respectively, for feces after a 48-h enrichment in a Yersinia selective broth. By the culture method, Y. enterocolitica was not detected in any of the swine specimens (n = 2,403) examined. By contrast, it was detected in 48 (2%) of the swine samples screened using the multiplex PCR and in 656 (27.2%) of these samples using the TaqMan assay. Using the culture method, Y. enterocolitica was detected in 8% of chitterling samples (n = 350) and in none of the ground pork samples (n = 350). It was identified in 27% of the chitterling samples using multiplex PCR and in 79% of these samples using the TaqMan assay. Ten percent of the ground pork samples contained Y. enterocolitica, as determined by the multiplex PCR, and 38% based on the TaqMan assay. The results suggest that pork products harbor more ail-bearing Y. enterocolitica than selected organs of freshly slaughtered hogs and that the TaqMan assay is more sensitive than either the multiplex PCR or traditional culture methods.

Genetic evidence on the origins of Indian caste populations

The origins and affinities of the approximately 1 billion people living on the subcontinent of India have long been contested. This is owing, in part, to the many different waves of immigrants that have influenced the genetic structure of India. In the most recent of these waves, Indo-European-speaking people from West Eurasia entered India from the Northwest and diffused throughout the subcontinent. They purportedly admixed with or displaced indigenous Dravidic-speaking populations. Subsequently they may have established the Hindu caste system and placed themselves primarily in castes of higher rank. To explore the impact of West Eurasians on contemporary Indian caste populations, we compared mtDNA (400 bp of hypervariable region 1 and 14 restriction site polymorphisms) and Y-chromosome (20 biallelic polymorphisms and 5 short tandem repeats) variation in approximately 265 males from eight castes of different rank to approximately 750 Africans, Asians, Europeans, and other Indians. For maternally inherited mtDNA, each caste is most similar to Asians. However, 20%-30% of Indian mtDNA haplotypes belong to West Eurasian haplogroups, and the frequency of these haplotypes is proportional to caste rank, the highest frequency of West Eurasian haplotypes being found in the upper castes. In contrast, for paternally inherited Y-chromosome variation each caste is more similar to Europeans than to Asians. Moreover, the affinity to Europeans is proportionate to caste rank, the upper castes being most similar to Europeans, particularly East Europeans. These findings are consistent with greater West Eurasian male admixture with castes of higher rank. Nevertheless, the mitochondrial genome and the Y chromosome each represents only a single haploid locus and is more susceptible to large stochastic variation, bottlenecks, and selective sweeps. Thus, to increase the power of our analysis, we assayed 40 independent, biparentally inherited autosomal loci (1 LINE-1 and 39 Alu elements) in all of the caste and continental populations (approximately 600 individuals). Analysis of these data demonstrated that the upper castes have a higher affinity to Europeans than to Asians, and the upper castes are significantly more similar to Europeans than are the lower castes. Collectively, all five datasets show a trend toward upper castes being more similar to Europeans, whereas lower castes are more similar to Asians. We conclude that Indian castes are most likely to be of proto-Asian origin with West Eurasian admixture resulting in rank-related and sex-specific differences in the genetic affinities of castes to Asians and Europeans.

Cloning and characterization of the gene encoding the glutamate dehydrogenase of Streptococcus suis serotype 2

Given the lack of effective vaccines to control Streptococcus suis infection and the lack of a rapid and reliable molecular diagnostic assay to detect its infection, a polyclonal antibody was raised against the whole-cell protein of S. suis type 2 and used to screen an S. suis gene library in an effort to identify protective antigen(s) and antigens of diagnostic importance. A clone that produced a 45-kDa S. suis-specific protein was identified by Western blotting. Restriction analysis showed that the gene encoding the 45-kDa protein was present on a 1.6-kb pair DraI region on the cloned chromosomal fragment. The nucleotide sequence contained an open reading frame that encoded a polypeptide of 448 amino acid residues with a calculated molecular mass of 48.8 kDa, in close agreement with the size observed on Western blots. A GenBank database search revealed that the derived amino acid sequence is homologous to the sequence of glutamate dehydrogenase (GDH) protein isolated from various sources, including conserved motifs and functional domains typical of the family 1-type hexameric GDH proteins, thus placing it in that family. Because of these similarities, the protein was designated the GDH of S. suis. Hybridization studies showed that the gene is conserved among the S. suis type 2 strains tested. Antiserum raised against the purified recombinant protein was reactive with a protein of the same molecular size as the recombinant protein in S. suis strains, suggesting expression of the gene in all of the isolates and antigenic conservation of the protein. The recombinant protein was reactive with serum from pigs experimentally infected with a virulent strain of S. suis type 2, suggesting that the protein might serve as an antigen of diagnostic importance to detect S. suis infection. Activity staining showed that the S. suis GDH activity is NAD(P)H dependent but, unlike the NAD(P)H-dependent GDH from various other sources, that of S. suis utilizes L-glutamate rather than alpha-ketoglutarate as the substrate. Highly virulent strains of S. suis type 2 could be distinguished from moderately virulent and avirulent strains on the basis of their GDH protein profile following activity staining on a nondenaturing gel. We examined the cellular location of the protein using a whole-cell enzyme-linked immunosorbent assay and an immunogold-labeling technique. Results showed that the S. suis GDH protein is exposed at the surface of intact cells.

Measurement of peripheral vestibular blood flow in a gerbil model of endolymphatic hydrops

Presently, many investigators believe that the dysfunction of microcirculatory mechanisms may be responsible for vestibular symptoms in Meniere's disease. This study, using intravital microscopy (IVM), a technique that provides in vivo microcirculatory measures, was designed to determine whether impaired vestibular blood flow exists in endolymphatic hydrops. Hydrops was induced in the gerbil model by obliteration of the vestibular aqueduct and was confirmed histologically after IVM. Posthydrops gerbil subjects at 8 weeks as well as control animals were prepared for IVM. With a customized intravital microscope, red blood cell velocity and vessel diameter measurements were calculated for individual arterioles and capillaries from the microvascular bed at the horizontal ampulla. Mean arteriole diameter was significantly larger in the control group than in the hydrops group, whereas mean capillary diameters were similar for both groups. No significant difference was observed for mean red blood cell velocity in capillaries or arterioles between control and hydrops animals.

Growth factor receptor gene and protein expressions in the human lens

In this study the mRNAs encoding epidermal growth factor receptor (EGFR), basic fibroblast growth factor receptor (FGFR-2) and insulin-like growth factor receptor (IGFR-1) genes of the human normal lenses at ages varying from 0.5 to 72 years, were identified by semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR). Regulation of EGFR gene expression in the lens did not change with aging, and of FGFR-2 and IGFR-1 genes also remained unaltered up to age 53 years. However, expressions of FGFR-2 and IGFR-1 genes were decreased at ages above 60 years. EGFR, FGFR-2 and IGFR-1 proteins were detected by immunoblot analysis in the epithelial cell membranes of lens at age varying from 40 to 72 years. There was no detectable amount of EGFR protein in fiber cell membranes of the lens, and the levels of FGFR-2 and IGFR-1 proteins were much lower than those in the epithelial cell membranes. The low levels of these receptor proteins in the fiber cell membranes of lens, suggest their possible role in keeping the differentiated function of these unique transparent cells. The findings of the increased protein levels with age of EGFR with the appearance of some degradation products at age 48 years and higher, and the increased FGFR-2 protein at age 60 years and higher in the epithelial cell membranes of lens, were of interest. It appears that this could be a compensatory protective response of the lens to aging process for lifelong continuation of normal growth by proliferation and differentiation of its epithelial cells into new fiber cells in the germinative zone at the equatorial region. Thus, these results could provide a basis for further studies on growth factor receptor gene and protein regulations in the mechanism of lens aging and progression of age-related human cataract.

Lens-specific regulation of the thioredoxin-1 gene, but not thioredoxin-2, upon in vivo photochemical oxidative stress in the Emory mouse

Thioredoxin (TRX)-1 and TRX-2 redox-regulatory genes were analyzed in the lens and some other tissues of the Emory mouse, a model for age-related human cataract. The cDNA transcripts of mRNAs encoding TRX-1 and TRX-2 genes were isolated and cloned by RT-PCR from the lens, liver, kidney, and tail, and the cDNA sequences were similar to the reported sequences of murine TRX-1 and TRX-2 genes. In vivo photochemical oxidative stress to the Emory mice resulted in fivefold upregulation of the lens TRX-1 gene at 3 weeks and declined thereafter. Western blot analysis revealed a fourfold increase of TRX-1 protein in the lens at 3 weeks after oxidative stress. The TRX-2 gene in the lens was not changed up to 5 weeks and decreased by 50% thereafter. However, the expressions of these genes in the liver, kidney, and tail were not changed. Fluorescent light or riboflavin alone did not affect the expressions of TRX-1 and TRX-2 genes in the lens. Thus, we show the expressions of TRX-1 and TRX-2 genes in the lens, liver, kidney, and tail and lens-specific upregulation of the TRX-1 gene and protein expressions, possibly as a protective response to the altered redox state of the lens after in vivo oxidative stress to the Emory mouse.

Facial nerve rehabilitation after radical parotidectomy

OBJECTIVE

Examine functional outcomes in patients undergoing radical parotidectomy and facial nerve grafting. Identify factors that may affect rehabilitation in these patients.

STUDY DESIGN

Retrospective chart review and photographic analyses of 12 patients undergoing radical parotidectomy with interposition nerve grafts for facial nerve reconstruction.

METHODS

Data obtained for each patient regarding age, sex, histology of parotid neoplasm, cable graft source, administration of postoperative radiotherapy, and treatment for eye rehabilitation. Functional outcomes were assessed with the House-Brackmann grading system at 6 months, 1 year, and 2 years after surgery.

RESULTS

All nerve grafts were harvested from cervical plexus sensory nerves with microscopic epineural repair performed for all neurorrhaphies. Overall, 9 of 12 patients achieved a grade III 2 years after surgery. All patients under age 30 obtained a grade III. Of the seven patients receiving postoperative radiation, five achieved a grade III. Older patients often required surgical procedures to facilitate eye closure.

CONCLUSIONS

Facial nerve rehabilitation after radical parotidectomy can be successfully achieved with cervical plexus interposition nerve grafts. Postoperative radiotherapy did not appear to affect return of function, and younger patients consistently achieved good functional outcomes after nerve grafting. Older patients frequently require surgical procedures for eye rehabilitation after radical parotidectomy.

Multiple origins of the mtDNA 9-bp deletion in populations of South India

The origins and genetic affinities of the more than 500 tribal populations living in South Asia are widely disputed. This may reflect differential contributions that continental populations have made to tribal groups in South Asia. We assayed for the presence of the intergenic COII/tRNALys 9-bp deletion in human mtDNA in 646 individuals from 12 caste and 14 tribal populations of South India and compared them to individuals from Africa, Europe, and Asia. The 9-bp deletion is observed in four South Indian tribal populations, the Irula, Yanadi, Siddi, and Maria Gond, and in the Nicobarese. Length polymorphisms of the 9-bp motif are present in the Santal, Khonda Dora, and Jalari, all of whom live in a circumscribed region on the eastern Indian coast. Phylogenetic analyses of mtDNA control region sequence from individuals with the 9-bp deletion indicate that it has arisen independently in some Indian tribal populations. Other 9-bp deletion haplotypes are likely to be of Asian and African origin, implying multiple origins of the 9-bp deletion in South India. These results demonstrate varying genetic affinities of different South Indian tribes to continental populations and underscore the complex histories of the tribal populations living in South Asia.

Novel euglycemic and hypolipidemic agents. 1

A series of [[(heterocyclyl)ethoxy]benzyl]-2,4-thiazolidinediones have been synthesized by the condensation of corresponding aldehyde 1 and 2,4-thiazolidinedione followed by hydrogenation. Both unsaturated thiazolidinedione 2 and its saturated counterpart 3 have shown antihyperglycemic activity. Many of these compounds have shown superior euglycemic and hypolipidemic activity compared to troglitazone (CS 045). The indole analogue DRF-2189 (3g) was found to be a very potent insulin sensitizer, comparable to BRL-49653 in genetically obese C57BL/6J-ob/ob and 57BL/KsJ-db/db mice. Pharmacokinetic and tissue distribution studies conducted on BRL-49653 and DRF-2189 (3g) indicate that these drugs are well-distributed in target tissues. On the basis of euglycemic activity as well as enhanced selectivity against reduction of triglycerides in plasma, DRF-2189 (3g) has been selected for further evaluation.

Structure-based design and synthesis of a series of hydroxamic acids with a quaternary-hydroxy group in P1 as inhibitors of matrix metalloproteinases

Examination of the S1 area of the active site of pro-stromelysin has led us to the design of novel and potent inhibitors of matrix metalloproteinases containing constrained quaternary-hydroxy group at P1. The synthesis and biological activity of these compounds with variations at P1', P2', and P3' will be described.

Requirements for both Rac1 and Cdc42 in membrane ruffling and phagocytosis in leukocytes

Specific pathways linking heterotrimeric G proteins and Fcgamma receptors to the actin-based cytoskeleton are poorly understood. To test a requirement for Rho family members in cytoskeletal events mediated by structurally diverse receptors in leukocytes, we transfected the full-length human chemotactic peptide receptor in RAW 264.7 cells and examined cytoskeletal alterations in response to the chemotactic peptide formyl-methionyl-leucyl-phenylalanine (FMLP), colony stimulating factor-1 (CSF-1), IgG-coated particles, and phorbol 12-myristate 13-acetate (PMA). Expression of Rac1 N17, Cdc42 N17, or the GAP domain of n-chimaerin inhibited cytoskeletal responses to FMLP and CSF-1, and blocked phagocytosis. Accumulation of F-actin- rich "phagocytic cups" was partially inhibited by expression of Rac1 N17 or Cdc42 N17. In contrast, PMA-induced ruffling was not inhibited by expression of Rac1 N17, but was blocked by expression of Cdc42 N17, indicating that cytoskeletal inhibition by these constructs was nonoverlapping. These results demonstrate differential requirements for Rho family GTPases in leukocyte motility, and indicate that both Rac1 and Cdc42 are required for Fcgamma receptor- mediated phagocytosis and for membrane ruffling mediated by structurally distinct receptors in macrophages.

LP-BM5 virus causes changes in lactic dehydrogenase and oxygen radical production in splenocytes of C57BL/6J mice

The LP-BM5 murine leukemia virus causes acquired immunodeficiency syndrome in C57BL/6J mice (MAIDS), similar to that of AIDS in humans. The objective of this study was to determine the effect of LP-BM5 viral infection on cellular activation and membrane integrity of splenocytes. Oxidative burst in splenocytes in response to exposure to PMA (20 microg/ml) was significantly higher (p<.02) in infected than in control mice at two weeks post-infection using luminol-enhanced chemiluminescence. By 13 weeks post-infection superoxide anion production in infected mice was significantly lower when compared to controls coinciding with decreased proliferative response to mitogens. The extent of cell membrane damage as indicated by lactic dehydrogenase (LDH) activity in serum was significantly higher in infected than in control mice (p<.001). The results from this study suggests that LP-BM5 virus causes an initial stimulation of cellular activity followed by a decreased cell activation characterized by decreased proliferation of splenocytes and decreased oxygen radical production. Decreased cell membrane integrity indicated by increased LDH activity may partly be responsible for these changes.

Effect of vitamin C on prostate cancer cells in vitro: effect on cell number, viability, and DNA synthesis

BACKGROUND

Many studies describe the protective role of vitamin C (ascorbic acid) against cancer development and in treatment of established cancer. The present study investigated whether ascorbic acid demonstrates a therapeutic benefit for prostate cancer.

METHODS

Androgen-independent (DU145) and androgen-dependent (LNCaP) human prostate cancer cell lines were both treated in vitro with vitamin C (0-10 mM). Cell counts, cell viability, and thymidine incorporation into DNA were determined.

RESULTS

Treatment of DU145 and LNCaP cells with vitamin C resulted in a dose- and time-dependent decrease in cell viability and thymidine incorporation into DNA. Vitamin C induced these changes through the production of hydrogen peroxide; addition of catalase (100-300 units/ml), an enzyme that degrades hydrogen peroxide, inhibited the effects of ascorbic acid. Superoxide dismutase, an enzyme that dismutates superoxide and generates hydrogen peroxide, did not prevent decreases in cell number and DNA synthesis, suggesting further the involvement of hydrogen peroxide in vitamin C-induced changes. These results clearly indicate that reactive oxygen species (ROS) are involved in vitamin C-induced cell damage. However, that singlet oxygen scavengers such as sodium azide and hydroquinone and hydroxyl radical scavengers such as D-mannitol and DL-alpha-tocopherol did not counteract the effects of ascorbic acid on thymidine incorporation suggests that vitamin C-induced changes do not occur through the generation of these ROS.

CONCLUSIONS

Vitamin C inhibits cell division and growth through production of hydrogen peroxide, which damages the cells probably through an as yet unidentified free radical(s) generation/mechanism. Our results also suggest that ascorbic acid is a potent anticancer agent for prostate cancer cells.

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.

Effect of bovine herpesvirus-1 on expression of interleukin-2 receptors and effect of interleukin-12 on lymphocyte proliferation

Expression of the interleukin-2 receptor alpha chain (IL-2R alpha) by peripheral blood mononuclear cells (PBMC) from Holstein calves, both experimentally-infected with bovine herpesvirus-l (BHV-l) and controls, was measured by flow cytometry. Expression of IL-2R alpha was 35 percent and 23 percent higher in infected calves than controls, on days 2 and 3 postinfection (PI), respectively. Concurrent with this increase in IL-2R alpha expression, a significant decrease (P < 0.001) was observed in the PHA-induced proliferative responses of PBMC from infected compared with control calves. In vitro treatment with recombinant human (rhu) IL-12 enhanced PHA-induced proliferative responses of PBMC from both infected and control calves. This rhuIL-12 enhancement of mitogen-induced proliferative responses was significant (P < 0.001) in infected calves on day 2 PI and was sufficient to abrogate the decrease observed due to BHV-1 infection. Since the expression of the beta and gamma chains of IL-2R was not measured it is difficult to speculate as to the status of high affinity receptor expression during BHV-1 infection. However results of the present study suggest that the decrease in proliferative responses observed during infection may not be due to a decrease in IL-2R alpha expression but may possibly be due to a selective down-regulation of signal transduction through IL-2R and/or by modulation of the expression of other cytokines involved in lymphocyte activation and proliferation.

Molecular characterization of a caprine adenovirus

Restriction endonuclease site maps were constructed for the genome of a caprine adenovirus (GAdV), strain NC90-7261, which was isolated in 1990 from a 3-year-old goat with encephalitis. Genomic GAdV DNA was digested with seven restriction endonucleases (RE). Genomic DNA libraries of GAdV were constructed by cloning BamHI and HindIII restriction fragments into a plasmid vector. Using cloned GAdV genomic fragments as probes in Southern blot hybridizations, an RE site map was constructed. The position of several clones was confirmed by limited nucleotide sequencing and the location of several RE sites was determined by single or double RE digestions of cloned fragments. The size of the GAdV genome was determined to be 28.2 kbp. The restriction pattern described in this report is different from that of other adenoviruses. Although the genomic organization of this GAdV is likely to be similar to that of other adenoviruses, the overall level of sequence similarity is low.

Effect of stress on interleukin-2 receptor expression by bovine mononuclear leukocytes

Holstein calves given three consecutive i.m. injections of dexamethasone (DEX) (0.04 mg kg-1) showed lymphopenia and neutrophilia with increased numbers of mature neutrophils on post-injection Days 1 and 2, but these values returned to normal levels by post-injection Day 3. Interleukin-2 receptor (IL-2R) expression by peripheral blood mononuclear cells (PBMC) was evaluated by flow cytometry using a monoclonal antibody specific for bovine IL-2R alpha. Treatment with DEX significantly decreased expression of IL-2R alpha in Concanavalin A (Con A)-activated PBMC on Day 1 (P < 0.02) and on Day 2 (P < 0.1). On Day 3, expression of IL-2R alpha by PBMC was similar in control and DEX-treated calves. This decrease in IL-2R alpha expression correlated with decreased proliferative responses of PBMC to the T-cell mitogens, phytohemagglutinin (PHA) and Con A. Following in vitro treatment with recombinant human (rhu) interleukin-12 (IL-12) Con A-induced proliferative responses of PBMC tended to be higher in both groups. However, the rhu IL-12 induced increase of Con A activated proliferative responses were significantly greater in DEX-treated calves than in control calves. IL-2R alpha expression by PBMC was found to be less in calves transported 800 km in a truck as compared to that in PBMC from controls. These data suggest that stress-induced immunosuppression in calves may involve decreased IL-2R alpha expression and decreased IL-12 production. Serum chemistry results indicated a trend toward higher creatine kinase (CK) levels in DEX-treated calves. This may be due to the lysis of corticosteroid sensitive lymphocytes.

Pathogenic mechanisms of caprine arthritis-encephalitis virus

Goats infected with caprine arthritis-encephalitis virus (CAEV) show chronic arthritis and cachexia, which are progressive in nature. The immunopathogenic mechanisms responsible for these progressive clinical symptoms have not been fully elucidated. Various haematological and immunological parameters were evaluated in experimentally-infected goats showing typical signs of CAEV-induced disease. Infected goats showed recurrent lymphocytosis that may be due to constant presentation of antigen by infected cells of a monocyte/macrophage lineage. The serum alkaline phosphatase and gamma-glutamyl transferase concentrations were elevated in infected goats, a characteristic of hepatic and bone disorders. All other serum chemistry parameters were similar between infected and control goats. Importantly, the serum tumour necrosis factor-alpha (TNF-alpha) levels were higher in infected goats. The cachexia seen in infected goats may be at least partly due to altered metabolism as a result of prolonged elevation of serum TNF-alpha levels. Depressed natural killer cell activity was observed in infected goats and may contribute towards the establishment of a persistent infection with CAEV.

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.

The effect of pre- and postweaning exposure to soybean meal on growth performance and on the immune response in the early-weaned pig

The effect of pre- and postweaning exposure to soybean meal on postweaning growth performance and immune response by the early-weaned pig was analyzed. In Exp. 1, treatments were assigned in a 2 x 2 x 2 factorial arrangement. Pigs were derived from gilts fed either a soybean meal- or a corn gluten meal-based diet during gestation and lactation. Six to eight pigs per litter were either stomach-infused with or without (placebo) soybean meal during d 5 to 9 after farrowing. At weaning, 240 pigs (initially 5.1 kg, 21 +/- 1 d) were randomly allotted to either a corn-soybean meal or a corn-dried skim milk-dried whey diet based on gilt and infusion treatments. Average daily gain, ADFI, and gain:feed ratio were decreased (P < .05) on d 0 to 14 postweaning for pigs fed a soybean meal diet compared with pigs fed a milk diet. Skin-fold thickness after intradermal injection of soy protein and casein extracts on d 6 and measured on d 7 postweaning was not affected (P > .10) by dietary treatment, but serum immunoglobulin G titers to soybean glycinin and beta-conglycinin were increased (P < .01). From d 14 to 35 postweaning, all pigs were fed a common (1.25% lysine) corn-soybean meal diet containing 10% dried whey. Average daily gain, ADFI, and gain:feed ratio were decreased (P < .05) from d 14 to 35 for pigs fed a milk diet on d 0 to 14 postweaning. Serum immunoglobulin G titers were higher (P < .01) on d 21 postweaning for pigs fed soybean meal for the entire nursery period. Cumulative ADG (d 0 to 35) and gain:feed ratio were decreased (P < .05) for pigs fed a milk diet from d 0 to 14 compared with pigs fed a soybean meal diet. In Exp. 2, 104 pigs (initially 5.3 kg, 21 +/- 1 d of age) were used to determine the effect of 0, 7.5, 15.0, and 22.5% soybean meal in a high-nutrient-dense starter pig diet. Differences were not detected (P > .10) in ADG, ADFI, and gain:feed ratio during d 0 to 14, but ADFI decreased (linear, P < .05) and gain:feed ratio increased (linear, P < .05) during d 14 to 35 and for the entire 35-d trial as the level of soybean meal increased.(ABSTRACT TRUNCATED AT 400 WORDS)

Immunopotentiation of bovine respiratory disease virus vaccines by interleukin-1 beta and interleukin-2

Three experiments, using 85 crossbred beef calves, were conducted to evaluate the adjuvanticity of single, multiple, and combined doses of recombinant bovine IL-1 beta (rBoIL-1 beta) and recombinant bovine IL-2 (rBoIL-2), with a modified-live bovine herpesvirus-1/parainfluenza-3 (BHV-1/PI-3) virus vaccine and a killed bovine viral diarrhea (BVD) virus vaccine. Cytokines were administered intramuscularly at vaccination but at different injection sites. All cytokine treatments increased non-major histocompatibility complex (MHC)-restricted cytolytic capability of peripheral blood mononuclear cells (PBMC) against virus-infected target cells and serum neutralizing (SN) antibody titers to BHV-1 and BVD virus. Multiple, consecutive injections of rBoIL-2 generally showed the greatest adjuvant effect, and no additive effect was observed when rBoIL-1 beta and rBoIL-2 were administered together. In a challenge experiment, calves were vaccinated with a modified-live BHV-1/PI-3 vaccine and infected with BHV-1 on Day 21. Cytokine-treated calves had higher SN antibody titers to BHV-1 than did the control calves at the time of challenge. Calves that were administered rBoIL-2 on 5 consecutive days shed less BHV-1 and had the highest SN antibody titer to BHV-1 (Day 28). These data suggest that rBoIL-1 beta and rBoIL-2 may be useful immunoadjuvants for bovine respiratory disease virus vaccines.

Isolation and characterization of monoclonal antibodies to recombinant bovine interleukin-1 beta

We describe the preparation of monoclonal antibodies (Mabs) directed against recombinant bovine interleukin-1 beta (rBoIL-1 beta). These anti-IL-1 beta Mabs were designated SA10, SA12, SA13, SA15, and SA22, and were characterized on the basis of their epitope specificity and cross-reactivity with homologous and heterologous cytokines in enzyme-linked immunosorbent assays and immunoblot analyses. Additionally, the ability of these Mabs to neutralize IL-1 beta was tested in thymocyte costimulation assays. The ELISA titers of all Mabs ranged from 9.4 x 10(6) to 1 x 10(7). Data indicate that Mabs SA10, SA12, SA15, and SA22 neutralized both bovine macrophage-derived IL-1 (1:4) and rBoIL-1 beta (1 ng ml-1). All the Mabs against rBoIL-1 beta (SA10, SA12, SA13, SA15, SA22) were specific and did not cross-react with other cytokines tested, except recombinant human IL-1 beta (rHuIL-1 beta). This finding suggests that these Mabs recognize epitopes common to human and bovine IL-1 molecules. Competition experiments suggested that Mab SA22 recognized a different epitope and Mabs SA10, SA12, SA13, and SA15 recognized the same epitope on the rBoIL-1 beta molecule. These observations suggest that these Mabs could be useful reagents for developing immunoassays to measure bovine IL-1 beta from biological fluids and to study the immunoregulatory role of IL-1 in the bovine immune system.

Neutrophil and lymphocyte response to supplementation with vitamins C and E in young calves

Calves, beginning at 3 d of age, were bottle-fed milk replacer unsupplemented, or supplemented with 10 g of vitamin C, or supplemented with 10 g of vitamin C plus 57 IU of vitamin E/kg of dry milk replacer (10 calves per treatment). Neutrophils from wk 2 and 4 blood samples were assayed for Staphylococcus aureus phagocytosis and neutrophil-mediated, antibody-dependent cellular cytotoxicity, and lymphocytes from those samples were assayed for concanavalin A-induced, phytohemagglutinin-induced, or pokeweed mitogen-induced proliferation. Ocular and nasal discharges of calves supplemented with vitamins C or C and E were less than those of controls for wk 1 to 8. Calves receiving supplementation with vitamin C and E tended to have higher mitogen-induced lymphocyte proliferative responses at wk 2. Neutrophil-mediated phagocytosis and antibody-dependent cellular cytotoxicity were lower at wk 2 and 4 for calves supplemented with vitamin C than for controls. Neutrophil function of calves supplemented with vitamins C and E together was near, or slightly higher than, that of unsupplemented calves for wk 2 and 4, suggesting that the addition of vitamin E negated the adverse effects that vitamin C alone had on neutrophil functions.

Interleukin 2 treatment of Staphylococcus aureus mastitis

A study was conducted in dairy cows to evaluate the efficacy of recombinant bovine interleukin 2 (rBoIL-2) as an adjunct to antibiotic therapy in Staphylococcus aureus mastitis. In normal, non-mastitic cows, intramammary infusion of rBoIL-2 caused a tenfold increase in somatic cell counts (SCC) in milk. Co-administration of 2 mg of rBoIL-2 and sodium cephapirin in cows with established S. aureus mastitis decreased SCC and shedding of S. aureus compared with values from cows that were given only sodium cephapirin or 10 mg rBoIL-2 with sodium cephapirin. Cows in the 2 mg rBoIL-2 group cleared the infection earlier and at 2 weeks after treatment had not relapsed with staphylococcal mastitis. These data suggest that rBoIL-2 may be useful as an immunotherapeutic agent in controlling mastitis.

Repeated restraint and isolation stress alters adrenal and lymphocyte functions and some leukocyte differentiation antigens in lambs

Lambs were used to evaluate the effect of repeated restraint and isolation stress (RIS) on secretion of cortisol, lymphocyte proliferative responses to mitogens, production of interleukin-2, and expression of leukocyte differentiation antigens. Differentiation antigens evaluated included cluster of differentiation antigens 2, 4, and 8 (CD2, CD4, and CD8, respectively); B cells; and major histocompatibility complex (MHC) class II, DQ, and DR. Lambs were assigned to either control (CON; n = 12) or to RIS treatment (n = 12) then were stanchioned in environmentally controlled rooms at 18 degrees C and constant light for 11 d before jugular vein catheters were inserted on d 0 of the experiment. On d 12, 13, and 14, lambs in the RIS treatment were removed to another location, restrained, and isolated from visual and tactile contact with other lambs for 6 h on each day. Following the 6-h stress treatment, lambs were returned to their home stanchions. The CON lambs remained in their stanchions. Samples of serum were obtained from all lambs, beginning before RIS (0 h) and at .5-h intervals until the completion of stress (6 h) on d 12 and 14. In addition, samples of whole blood were obtained at 0 and 6 h on d 12, 13, and 14 for evaluation of immune function characteristics. Fitted polynomial curves describing the cortisol response in RIS and CON lambs differed (P less than .005) on both d 12 and 14, reflecting the unmistakable increase in cortisol in response to the stressor.(ABSTRACT TRUNCATED AT 250 WORDS)

Response of young dairy calves with lasalocid delivery varied in feed sources

Growth, age at weaning, fecal scores, and blood metabolites of young dairy calves were measured to determine the most effective method of lasalocid administration. Forty Holstein bull calves were blocked by date of birth and assigned randomly to one of four treatment groups: no lasalocid; lasalocid in starter; lasalocid in prestarter and starter; or lasalocid in milk, prestarter, and starter for a 12-wk period. Calves were fed milk twice daily until they consumed 227 g/d of prestarter, at which time the p.m. milk feeding was discontinued, and starter was offered for ad libitum intake as a mixture with the 227 g/d of prestarter. When total dry feed consumption reached 1.3% of birth weight, the calf was weaned. When the calf was 5 wk of age, the prestarter was discontinued. Daily gain tended to be greatest during the first 6 wk for the calves receiving lasalocid in milk, prestarter, and starter. These calves also were weaned with less variation in days to weaning. By wk 8 through 12, there were no differences in gain among the treatment groups.

Interrelationship between hypersensitivity to soybean proteins and growth performance in early-weaned pigs

The objective of this growth trial was to determine the interrelationship between immunological criteria, gut morphology, and performance of starter pigs fed soybean proteins processed by different methods. One hundred twenty-five pigs were orally infused with 6 g/d of either dried skim milk, soybean meal (48% CP), soy protein concentrate, extruded soy protein concentrate, or experimental soy protein concentrate from 7 to 11 d of age and then fed a diet containing the same protein sources from weaning (d 21) to 35 d of age. All pigs were fed a corn-soybean meal diet containing 10% dried whey, 1.25% lysine, and 3% soybean oil for the remaining 21 d of the experiment. Xylose absorption and anti-soy immunoglobulin G (IgG) titers were measured on d 6 postweaning, and skin-fold thickness after intradermal injection of protein extracts was measured on d 7 postweaning. A total of 25 pigs (five pigs/treatment) was euthanatized on d 7 postweaning. Villus height and crypt depth from duodenum samples were measured. These measurements were obtained to elucidate a relationship between the hypersensitivity responses to soybean products and growth performance of baby pigs. Pigs fed diets containing soybean meal had a lower (P less than .05) rate of gain (d 0 to 14) and villus height, higher (P less than .01) serum anti-soy IgG titers, and increased skin-fold thickness (d 6 and 7 postweaning) after intradermal injection compared with those fed dried skim milk. Pigs fed other soy proteins also had lower ADG from d 0 to 14 postweaning; however, pigs fed moist extruded soy protein concentrate tended (P less than .09) to have higher ADG and improved feed utilization when compared with pigs fed soybean meal (d 0 to 14).(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of recombinant fibroblast interferon and recombinant immune interferon on growth and the antigenic phenotype of multidrug-resistant human glioblastoma multiforme cells

To study the effect of drug resistance on the response of stage IV astrocytomas to interferon, a human glioblastoma multiforme cell line, GBM-18, was transfected with an expression-vector plasmid containing a human multidrug resistance (MDR) gene (pHaMDR1/A), and clones surviving in colchicine were isolated. GBM-18 multidrug-resistant subclones displayed cross-resistance to other chemotherapeutic agents, including vincristine, doxorubicin, and dactinomycin. The multidrug-resistant phenotype was reversible when GBM-18 multidrug-resistant cells were cultured in colchicine and the calcium-channel blocker verapamil. The level of the MDR1 gene (also known as PGY1) message was increased in GBM-18 multidrug-resistant cells selected for increased resistance to colchicine, and this effect was not correlated with an amplification of the MDR1 gene. In both parental GBM-18 and GBM-18 multidrug-resistant cells, growth was suppressed to a greater degree when cultures were treated with the combination of fibroblast interferon (IFN-beta) and immune interferon (IFN-gamma). Parental cells and multidrug-resistant subclones varied in their de novo and/or interferon-modulated expression of HLA class I and class II antigens, a high-molecular-weight melanoma-associated antigen, and intercellular adhesion molecule 1 (ICAM-1). Of the antigens tested, ICAM-1 and HLA class I antigens were the most sensitive to enhanced expression induced by IFN-beta and IFN-gamma when used alone or in combination. The results of the present study indicate that multidrug-resistant human glioblastoma multiforme cells retain their increased sensitivity to the antiproliferative activity of the combination of IFN-beta plus IFN-gamma, and differences in antigenic phenotype are apparent in independent multidrug-resistant glioblastoma multiforme clones.

Measuring suitability of soybean products for early-weaned pigs with immunological criteria

Two trials were conducted to determine the suitability of soybean products for baby pigs. Weanling pigs (n = 40 and 48 in Trials 1 and 2, respectively) were infused orally (6 g/d) with dried skim milk, soybean meal (SBM, 48% CP); soy protein concentrate, moist extruded soy protein concentrate, or soy protein isolate from d 7 to 12 of age. Pigs were then fed a diet containing the same protein source for 1 (Trial 1) or 2 (Trial 2) wk after weaning (d 21 of age). To avoid exposure of pigs to soybean proteins, the dams of pigs were fed a corn-corn gluten meal-based diet supplemented with lysine and tryptophan from d 109 of gestation. All pigs in Trial 1 were killed at 28 d of age, and samples of ileal digesta and small intestine were obtained. In Trial 2, the soy protein isolate was not included, and all pigs were fed a diet containing 4% soybean oil and 1.25% lysine for the last 3 wk of the trial. Growth performance, skin-fold thickness, after intradermal injection of extracts of the corresponding proteins, and anti-soy immunoglobulin G (IgG) titers were measured. Results indicated that pigs fed diets containing SBM had lower (P less than .05) villus height and xylose absorption but higher (P less than .05) serum anti-soy IgG titers and increased skin-fold thickness compared with the mean of pigs given milk and all other soy treatments.(ABSTRACT TRUNCATED AT 250 WORDS)

Repeated restraint and isolation stress in lambs increases pituitary-adrenal secretions and reduces cell-mediated immunity

Rambouillet crossbred ewe lambs were used to evaluate the effect of repeated restraint and isolation stress (RIS) on endocrinological and immunological functions. Lambs were blocked by weight and assigned to either RIS (n = 6) or to control (CON; n = 6) treatments. All lambs were tethered in environmentally controlled rooms at 22 degrees C with constant light and, at this time (d 0), were given 1 mg of ovalbumin in adjuvant. On d 12, catheters were placed nonsurgically into the jugular vein of all lambs, and they were reimmunized with .5 mg of ovalbumin in incomplete adjuvant. Each lamb in the RIS treatment group was removed from its home stanchion, isolated from visual and tactile (but not auditory and olfactory) contact with other lambs, and restrained for 6 h on d 14, 15, and 16. Lambs in CON treatment remained undisturbed in their home stanchions. Lymphocyte blastogenic function and production of interleukin-2 (IL-2) were assessed in samples of blood collected before and at the conclusion (0 and 6 h) of each of the three stress bouts. In addition, ACTH and cortisol secretion in response to RIS was evaluated in samples of plasma and serum collected at .5-h intervals on the first and last days of stress (d 14 and 16). Finally, antibody production in response to immunization against ovalbumin was assessed in samples of serum obtained 14 d after reimmunization on d 12 of the study. Polynomial curves fit to the ACTH and cortisol data differed (P less than .005) on both d 14 and 16 between RIS and CON treatments.(ABSTRACT TRUNCATED AT 250 WORDS)

Removal of nocturnal secretion of melatonin fails to reduce antibody synthesis and interleukin-2 production of lambs

Crossbred ewe and wether lambs were used to evaluate the effects of a normal, nocturnal elevation in the concentration of melatonin in the serum on immunological functions. The nocturnal elevation in melatonin was eliminated by exposing half the lambs to constant light (LL), whereas the remainder received a 12-h light, 12-h dark cycle (LD). Immune function was challenged by treating half the lambs in LL and half of the lambs in LD with dexamethasone (DEX; .04 mg/kg); the remainder of the lambs received only a saline vehicle (SAL). The resulting treatment combinations were designated LD+SAL (n = 5), LD+DEX (n = 5), LL+SAL (n = 5), and LL+DEX (n = 5). Lambs were stanchioned individually in environmental rooms; photoperiod treatments commenced on that day (d -14). Also on d -14, lambs were given 1 mg ovalbumin/lamb in adjuvant. Lambs were given a booster injection of .5 mg ovalbumin/lamb on d 0. Treatments with DEX and SAL also began on d 0 and were repeated every 48 h through d 14. Catheters were placed in the jugular vein of all lambs on d 12; samples of plasma and serum were collected hourly from 0800 on d 14 to 0800 on d 15; plasma was assayed for adrenocorticotropic hormone (ACTH) and serum was assayed for cortisol and melatonin. In addition, samples of serum obtained at 0800 on d 15 were used to evaluate antibody titers to ovalbumin. Samples of whole blood also were obtained at 0800 on d 15, and total and differential leukocyte numbers and production of interleukin-2 (IL-2) by lymphocytes were determined.(ABSTRACT TRUNCATED AT 250 WORDS)

Rat urate oxidase: cloning and structural analysis of the gene and 5'-flanking region

The structural gene (UOX) encoding rat urate oxidase (UOX) spans at least 23 kb and is composed of eight exons and seven introns. All of the exon-intron splice junction sequences conformed to the GT/AG consensus established for eukaryotic genes. The transcription start point (tsp) was determined using S1-type nuclease protection riboprobe, and assigned to an adenine 54 nucleotides (nt) upstream of the ATG start codon. A 456-bp 5'-terminal fragment, starting at the ATG codon, carries a putative TATA (ATAAAA) sequence at -32, and two putative 'CAAT box' sequences at -62 and -71 bp upstream from the tsp. No sequence resembling 'GC' box hexanucleotides (GGGCGG or CCGCCC) was found. The structural features of the 5'-flanking region of the UOX gene are distinct from the 5'-flanking sequences of peroxisomal beta-oxidation system genes which contain one or more 'GC' box elements but lack TATA- and CAAT-like features [Osumi et al., J. Biol. Chem. 262 (1987) 8138-8143; Ishii et al., J. Biol. Chem. 262 (1987) 8144-8150]. The 5'-flanking region of the UOX gene reveals a sequence, TTAGTAATT at nt -276 from the tsp, which appears to be complementary to the underlined part of the liver-specific LF-B1/HNF-1 consensus sequence, GTTAATNATTAAC (where N = A, C, T, G or no nt).

Induction of immune response to bovine herpesvirus-1 with anti-idiotypic antibodies

Previously, we prepared rabbit anti-idiotypic (anti-Id) antibodies against murine monoclonal antibodies (MAbs) specific for the major bovine herpesvirus-1 (BHV-1) envelope glycoproteins. Glycoprotein III (gIII) contains neutralization epitopes and may be the virus attachment protein. Anti-Id antibodies to a neutralizing MAb that reacts with gIII were purified by sequential immunoaffinity chromatography. Immune responses to the purified anti-Id reagent and BHV-1 were compared in mice. Both groups of mice produced BHV-1-specific neutralizing antibodies. However, lymphocyte proliferative responses and interferon and interleukin-2 production were specific for the respective immunizing antigens. These results suggest that the anti-Id reagent may bear an internal image of a B-cell-stimulating epitope of glycoprotein gIII; however, this epitope does not stimulate a virus-specific cellular immune response in mice.

Bovine recombinant granulocyte-macrophage colony-stimulating factor enhancement of bovine neutrophil functions in vitro

Neutrophils were purified from blood of dexamethasone-treated (0.04 mg/kg of body weight) and untreated calves. Cells were untreated (controls) or cultured in media containing 5 or 10 ng of bovine recombinant granulocyte-macrophage colony-stimulating factor (rbGM-CSF)/ml for 10 to 12 hours before being tested for various functions. Dexamethasone treatment of calves decreased luminol-dependent chemiluminescence, decreased phagocytosis of Pasteurella multocida and several Staphylococcus spp by various degrees, and decreased antibody-dependent cell-mediated cytotoxicity against bovine herpesvirus-infected cells by 26 to 32%. The percentage phagocytosis of coagulase-positive S aureus and S intermedius was higher than that of coagulase-negative S epidermidis for neutrophils from all calves. Culture of neutrophils with rbGM-CSF significantly increased (P less than 0.05) all of the aforementioned functions, compared with control neutrophils; however, rbGM-CSF-induced increases in function tended to be higher in neutrophils from dexamethasone-treated calves than in neutrophils from untreated calves.

Transient hypersensitivity to soybean meal in the early-weaned pig

An experiment was conducted to determine whether baby pigs develop hypersensitivity to dietary soybean proteins. Thirty-two pigs were orally infused with either dried skim milk (5 g/d; control) or soybean meal (48% CP; 5 g/d) from d 7 to 14 after birth. Sows were fed a corn-corn gluten meal-based diet supplemented with lysine and tryptophan to avoid exposure of pigs to soybean proteins. Pigs were weaned at 21 d of age and fed diets containing either soybean meal or milk proteins until d 56. One half of the pigs were killed at 28 d of age and the rest at 56 d of age. Segments of small intestine were collected, and intraepithelial lymphocytes were isolated. At 28 d of age, pigs fed diets containing soybean meal had lower (P less than .05) villus height (221 vs 298 microns) and rate of gain (86 vs 204 g/d) than control pigs did. Pigs fed a diet containing soybean meal had higher (P less than .05) immunoglobulin G (IgG) titers to soybean protein than did pigs fed a milk protein-based diet. Blood and intestinal lymphocytes collected on d 28 and 56 did not exhibit any proliferative response when cultured with purified soy proteins (2.5 or 5 microns/ml). Phytohemagglutinin- and pokeweed mitogen-induced lymphocyte proliferations were higher (P less than .05) at d 56 than at d 28, but there were no differences attributable to protein source. There were no differences (P greater than .05) in skin-fold thickness measurements following intradermal injection with soy or milk proteins. Decreased villus height and increased serum IgG titers to soybean proteins coinciding with inferior performance of early weaned pigs fed diets containing soybean meal indicate that conventionally processed, commercial soybean meal may retain some antigens that can cause transient hypersensitivity in piglets.

Bovine recombinant interleukin-2 augments immunity and resistance to bovine herpesvirus infection

The in vivo administration of bovine recombinant interleukin-2 (rIL-2) was evaluated in calves vaccinated and then challenged with bovine herpesvirus-1 (BHV-1). In Experiment 1, 24 calves were allotted to four groups: control; bovine rIL-2; BHV-1 vaccine (modified-live); and bovine rIL-2 + BHV-1 vaccine. Serum neutralizing antibody titers to BHV-1 were increased sixfold, and virus shedding was fourfold less in calves vaccinated and treated with rIL-2 (25 micrograms/kg, intramuscularly) when compared to calves that received vaccine only. Treatment with rIL-2 induced lymphokine-activated killer activity that was eliminated by pretreating effector cells with complement and a monoclonal antibody (B26A) specific for the sheep red blood cell receptor. The rIL-2 treatment in BHV-1-vaccinated calves increased the calves' ability to withstand a BHV-1 challenge. However, during treatment with rIL-2, calves developed diarrhea and mild fever that abated after IL-2 treatment was stopped. A second experiment was then conducted to determine a dose of rIL-2 that would enhance immunity to BHV-1 without causing adverse side effects. Twenty-five calves were allotted to five groups that received injections of rIL-2 at 0.0, 25.0, 2.5, 0.25, or 0.025 micrograms kg-1 day-1 for 5 days. All calves received a modified-live BHV-1 vaccine. Calves treated with 25.0 micrograms kg-1 day-1 showed similar adverse side effects as in the first experiment but all other calves were normal. Compared to control calves, those treated with 25.0, 2.5, and 0.25 micrograms kg-1 day-1 of rIL-2 had higher (P less than 0.05) serum antibody titers to BHV-1 and following challenge lower (P less than 0.05) BHV-1 titers in nasal secretions; additionally, clinical disease as evidenced by nasal and ocular discharge was less severe (P less than 0.05). In vitro cytotoxic responses against BHV-1-infected bovine kidney cells were increased (P less than 0.05) in calves treated with rIL-2 in a dose dependent manner. These data suggest that bovine rIL-2 at 2.5 to 0.25 micrograms/kg may be an effective adjuvant to immunization.

Effects of bovine respiratory disease viruses and isoprinosine on bovine leukocyte function in vitro

Peripheral blood mononuclear cells obtained from 4- to 6-month-old-calves were inoculated in vitro with bovine herpesvirus-1, parainfluenza-3, or bovine virus diarrhea viruses. No increase in infectious virus progeny was observed; however, the viruses were detected in the cells for at least 96 h post-infection without any significant reduction in cell viability. The three viruses, either alone or in combination, suppressed phytohemagglutinin-induced proliferation of the mononuclear cells. The greatest suppression was observed in cultures inoculated with bovine virus diarrhea virus. Addition of isoprinosine partially restored this viral-induced suppression of proliferative response, and the efficiency of reversal was greater in bovine virus diarrhea virus-infected cells. Interleukin-2 activity was higher in cultures of virus-infected mononuclear cells than in cultures of non-infected cells.

Cloning and expression in Escherichia coli of an esterase-coding gene from the oil-degrading bacterium Acinetobacter calcoaceticus RAG-1

A putative esterase gene (est) from Acinetobacter calcoaceticus RAG-1 has been cloned into Escherichia coli. Esterase-positive clones exhibited high levels of esterase activity even in intact cells. In addition, expression of the est gene conferred on E. coli the ability to grow on simple triglycerides such as triacetin (TAC). The original esterase-positive plasmid pRA17 carried a 2.2-kb insert from a partial MboI digest of RAG-1 DNA, which gave a single band with RAG-1 DNA following Southern hybridization. By subcloning and sequencing the est gene was found to contain a sequence of 870 bp which could be translated to yield a protein of Mr 32,700. In support of the sequencing results was the finding that when pRA17 was expressed in minicells, a unique peptide of Mr 32,500 was identified. This peptide was not found in minicells transformed with esterase-negative plasmids, such as pRA176, which contained a Tn5 insertion in the est gene. The fact that the production of active esterase depended on the orientation of the est gene within the vector suggested that transcription proceeded from the tet promoter in pBR322.

The nucleotide sequence of a full length cDNA clone encoding rat liver urate oxidase

Recently we reported the sequence of a cDNA clone (pUOX-1), isolated from a lambda gt11 cDNA library, which encoded for rat liver urate oxidase (EC 1.7.3.3), but this clone lacked the nucleotide sequences encoding the N-terminal region for this enzyme. Using the cDNA insert from the pUOX-1 clone as a probe, we have now isolated a full length cDNA clone, pUOX-2, from a lambda gt10 library by plaque hybridization. Nucleotide sequence analysis of the pUOX-2 clone showed that it has 1379 base pairs with an open reading frame coding for 303 amino acid residues corresponding to a molecular mass of 34,931 daltons. In addition to the open reading frame the pUOX-2 contains 439 bp of 3'-untranslated and 41 bp of 5'-untranslated sequences. The consensus polyadenylation signal AATAAA precedes a stretch of poly(A)+ residues at the 3' end.

Bovine herpesvirus-1 and parainfluenza-3 virus interactions: clinical and immunological response in calves

Calves infected with bovine herpesvirus-1 (BHV-1) or both BHV-1 and parainfluenza-3 virus (PIV-3) developed clinical signs including fever, cough, and nasal and ocular discharges. Animals infected with both viruses appeared more depressed and showed higher rectal temperature, while calves inoculated with PIV-3 alone had a very mild clinical disease. Both BHV-1 and PIV-3 were recovered from nasal secretions up to six to eight days postinoculation. However, the virus titers were lower in calves with mixed infection. An increase in serum antibodies to both BHV-1 and PIV-3 was detected by serum neutralization and enzyme-linked immunosorbent assay. Antibody responses were delayed and significantly lower in calves given mixed infection than in calves infected with a single virus. Interleukin-2 activity in cultures of lymphocytes from BHV-1 and BHV-1 plus PIV-3 infected calves was higher compared to control calves.

Differential induction and regulation of peroxisomal enzymes: predictive value of peroxisome proliferation in identifying certain nonmutagenic carcinogens

Hypolipidemic drugs and certain plasticizers markedly increase the number of peroxisomes in liver parenchymal cells. Continued exposure to peroxisome proliferators has been shown to produce essentially similar pleiotropic responses leading eventually to the development of liver tumors in rats and mice. These agents are not mutagenic in short-term test systems and do not appear to interact with or damage DNA. Accordingly, the events leading to or associated with the induction of peroxisome proliferation have been postulated to play a role in the development of liver tumors. Recent evidence indicates that persistent peroxisome proliferation leads to the formation of 8-hydroxyguanosine in rat liver DNA, which supports the role for oxidative stress. The mRNAs of the three peroxisomal beta-oxidation genes are induced over 20-fold in the livers of rats treated with nafenopin, Wy-14643, BR-931, and other structurally diverse peroxisome proliferators. This increase in beta-oxidation mRNAs is evident within 30 min to 1 hr and was maximal 8 to 16 hr after the administration of a single dose of these agents by gavage. The peroxisomal catalase and urate oxidase mRNAs increase about 2-fold in the livers of rats treated chronically with peroxisome proliferators. These results indicate that peroxisome proliferators differentially regulate different peroxisomal enzymes. The tissue specificity of peroxisomal beta-oxidation gene regulation by xenobiotics supports the contention that the development of liver tumors following exposure to peroxisome proliferators correlates well with the inducibility of peroxisome proliferation and the beta-oxidation genes. Although these agents are known to exert mitogenic response in liver, it is unlikely that stimulation of DNA synthesis alone is responsible for tumor development. Cell proliferation may, however, play a secondary role. The morphological phenomenon of peroxisome proliferation should serve as a simple, sensitive, and valuable biological indicator for the identification of nongenotoxic or nonmutagenic chemicals that may be carcinogenic. An understanding of the cellular and molecular basis of peroxisome proliferation is a prerequisite for the evaluation of toxicological implications of this phenomenon.