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Biomedical subjects

D A Mosier

Publications and source records attributed to D A Mosier.

At least 37 records · Page 2Linked to original sources
PubMed1995

Passive protection of calves with Pasteurella haemolytica antiserum.

Four colostrum-deprived calves each were immunized passively with antisera to whole Pasteurella haemolytica, leukotoxin-containing supernatants of P haemolytica, P haemolytica lipopolysaccharide, or newborn calf serum. Calves were challenge exposed intrabronchially with 5 x 10(9) P haemolytica, and 24 hours later, the resulting lesions were evaluated. The greatest protection against challenge exposure was provided by the antiserum to whole P haemolytica (lesion score = 6.3), whereas newborn calf serum provided the least protection (lesion score = 28.3). Calves that received antiserum to P haemolytica supernatants were moderately protected (lesion score = 16.3), and the antiserum to lipopolysaccharide provided minimal protection (lesion score = 21.8). Antibodies that were unique to whole P haemolytica antiserum and produced dense bands on immunoblots were detected to antigens at 66, 50, and 30 kd. Antibodies in the supernatant preparation that produced prominent bands reacted to antigens between 100 and 90 kd. Collectively, antibodies to these antigens may be responsible for enhancing resistance to experimentally induced pneumonic pasteurellosis. Antibodies to antigens in P haemolytica lipopolysaccharide provided little to no protection.

Animals↗
PubMed1994

Identification of a potentially important antigen of Pasteurella haemolytica.

To identify antigens which may be important for stimulating immunity to pneumonic pasteurellosis, a bovine antiserum to whole P. haemolytica was used to screen a recombinant lambda gt11/P. haemolytica expression library. One of the recombinant bacteriophage clones identified with the bovine antiserum, SW20C, expressed a fusion protein which was also recognized by rabbit antiserum to partially purified P. haemolytica culture supernatant and was found to be immunogenic in guinea pigs. The guinea pig antibody recognized a 100 kDa protein in P. haemolytica cell lysates. Sequence analysis of the cloned DNA from SW20C identified a fragment of 1446 bp with a small open reading frame that was contiguous with the lacZ sequence. The 153 bp P. haemolytica-specific open reading frame encoded a polypeptide of approximately 6 kDa. Homology searches of Genbank and the EMBL data bases revealed no homology of this open reading frame with any other bacterial sequences including P. haemolytica leukotoxin and Ssa1. Evaluation of sera from calves that were scored either susceptible or resistant to experimental pneumonic pasteurellosis demonstrated a significant (P < 0.001) correlation between the intensity of the antibody response to the SW20C antigen and resistance to disease.

Amino Acid Sequence↗
PubMed1994

Seroprevalence of cryptosporidial antibodies during infancy, childhood, and adolescence.

Cryptosporidium parvum causes mild to moderately severe diarrhea in immunocompetent individuals. Cryptosporidial antibodies in the sera of 803 children seen at Children's Hospital of Oklahoma were measured by means of an ELISA. Thirteen percent of children younger than 5 years of age were seropositive for antibodies to C. parvum. The seropositivity rate for children who attended day-care facilities was higher than that for those who did not. In addition, children in this age group with a history of recent diarrhea were seropositive at a higher rate than were children without diarrhea. Thirty-eight percent of children (5-13 years of age) and 58% of adolescents (14-21 years of age) were seropositive for antibodies to C. parvum. Blacks and Native Americans in these age groups had higher seropositivity rates than did White non-Hispanics. There were no differences in seropositivity rates between sexes or between residents of the largest urban counties in Oklahoma and residents of the more rural counties. Exposure to C. parvum during childhood is common in Oklahoma. Socioeconomic factors may play a role in early exposure to this protozoal pathogen.

Adolescent↗
PubMed1994

Experimental Brucella abortus strain 19 arthritis in young cattle.

Several reports have shown an association between lameness in cattle and vaccination with Brucella abortus strain 19. Affected joints are culture negative for Brucella, but the synovial fluid is positive for B. abortus antibodies. The joints contain cloudy fluid, with villous proliferation of the synovium. Brucella abortus antigens are often found in the synovium with fluorescent antibody staining. This report describes the experimental reproduction of a chronic synovitis in 6 young Angus steers using intra-articular injections of B. abortus strain 19. The carpal and tibial joints were injected with 5 x 10(9) colony-forming units/ml of B. abortus strain 19 and regularly biopsied over a 28-day period. Steers started becoming serologically positive for B. abortus on post-inoculation day (PID) 5 and were all positive by PID 7. Joints were cultured and examined by fluorescent antibody staining, immunohistochemical methods, and light and transmission electron microscopy. Lesions typical of the field cases were present by PID 21. Brucella abortus was cultured more often during PID 1-5 (6 of 9 joints) than during PID 7-28 (3 of 15 joints). Brucella abortus was only found on PID 1 and 5 by fluorescent antibody staining and in only 2 joints immunohistochemically on PID 5 and 7. The reproduction of lesions typical of field cases but the inability to locate B. abortus antigens in the synovium raises the question of whether in field cases the synovium is continually or intermittently seeded with bacteria or if factors other than just the bacterium are needed to perpetuate the lesion.

Animals↗
PubMed1994

Inability of interferon-gamma and aminoguanidine to alter Cryptosporidium parvum infection in mice with severe combined immunodeficiency.

Severe combined immunodeficiency (scid) mice have been useful in identifying specific host defense systems responsible for containing and eradicating Cryptosporidium parvum infection. Adult scid mice were given C. parvum oocysts and treated weekly with monoclonal antimurine interferon-gamma (anti-IFN-gamma). Anti-IFN-gamma-treated mice had more cryptosporidia seen in the intestines and had more severe morphologic changes associated with disease than control mice. To assess the mechanism of this effect, infected adult BALB/c and scid mice were treated with the nitric oxide synthase inhibitor, aminoguanidine. Infection in aminoguanidine-treated mice was not significantly different from that in control mice. Next, the effects of pharmacologic doses of IFN-gamma (10,000 IU) on the course of cryptosporidiosis in newborn scid mice were evaluated. IFN-gamma did not reverse the initial susceptibility of neonatal scid mice to cryptosporidiosis and continued treatment with IFN-gamma (10,000 IU weekly) did not alter survival. We conclude that IFN-gamma does not exert its anticryptosporidial effect by stimulation of nitric oxide production. Deficient IFN-gamma production by neonatal lymphocytes does not appear to be responsible for the increased severity of infection observed in neonatal animals. Also, IFN-gamma may not be useful in treating immunocompromised patients with cryptosporidiosis.

Amino Acid Oxidoreductases↗
PubMed1994

Acute effects of perineural administration of sodium hyaluronate on palmar digital neurectomy sites in horses.

Biaxial palmar digital neurectomy of all limbs was performed on 6 mixed-breed castrated adult male horses, using a standard guillotine method. Using a Teflon catheter, 20 mg (2 ml) of sodium hyaluronate (group 1), 2 ml of phosphate-buffered saline solution (group 2), or catheter placement with no infusion (group 3) was applied to 4 (group 1) or 2 (groups 2 and 3) of 8 incisions/horse. Treatments were administered after closure of the neurectomy incision, and the catheter was removed. Horses were evaluated daily for 1 week, then weekly over a 9-week period for evidence of lameness, swelling, and ultrasonographic changes. On week 9, horses were euthanatized and neurectomy sites were removed en bloc for histologic evaluation of axonal regrowth, inflammation, and fibrosis. Neither lameness nor sign of painful neuroma was observed clinically in any of the horses. Neurectomy eliminated cutaneous heel sensation in all limbs for the duration of the study. Swelling was evident at all neurectomy sites. There were no significant differences between treatment sites for measurement of pastern circumference or ultrasonographic evaluation of incisional swelling. Foci of ultrasonographic hyperechogenicity increased over time, but there was no significant difference in hyperechogenicity between treatment groups. Histologic evidence of neuroma formation was observed at all sites. Morphometric assessment of neuroma cross-sectional areas revealed no significant difference between the groups, as did subjective histologic assessment of neuroma density and fibrous tissue content.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Topical↗
PubMed1994

Antigenic composition of Pasteurella haemolytica serotype-1 supernatants from supplemented and nonsupplemented media.

Supernatant preparations containing antigens produced by Pasteurella haemolytica serotype 1 grown in nonsupplemented RPMI 1640 medium and 3 grown in supplemented RPMI 1640 media were evaluated. Antigens were detected by immunoblotting each supernatant preparation with sera from 20 cattle with various degrees of resistance to experimentally induced pneumonic pasteurellosis. Antigen-antibody bands at 49 and 30 kd were correlated with resistance in all 4 media. A 66-kd antigen-antibody band was correlated with resistance in 2 media, and antigen-antibody bands at 100 and 16 kd were correlated with resistance in 1 medium each. These results indicated that the number and relative amount of resistance-associated antigens in P haemolytica supernatants can be optimized on the basis of type of growth medium used.

Animals↗
PubMed1993

Cryptosporidium parvum infection after abrogation of natural killer cell activity in normal and severe combined immunodeficiency mice.

The role of natural killer (NK) cell activity in adult mice with severe combined immunodeficiency (scid mice) infected with Cryptosporidium parvum oocytes was evaluated. Adult BALB/c and scid mice were inoculated intragastrically with 10(6) C. parvum oocysts after the administration of anti-asialo-GM1 or control normal rabbit serum. Groups of animals were evaluated for splenic NK cell activity and examined histopathologically at 2, 4, and 6 wk postinfection. Virtual elimination of splenic NK cell activity by anti-asialo-GM1 treatment was demonstrated. Nonetheless, no differences in the occurrence of illness, death, or histopathologic evidence of infection were observed between anti-asialo-GM1-treated and control-treated BALB/c or scid mice. We conclude that NK cell activity, at least as measured in the spleen, does not play a significant role in murine host defense of cryptosporidial infection, even in the absence of functional B and T cells.

Animals↗
PubMed1992

Renal amyloidosis in a family of beagles.

Renal amyloidosis was confirmed in 6 related male and female Beagles, ranging in age from 5 to 11 years. The most commonly reported signs of illness included lethargy, anorexia, vomiting, and weight loss. Common clinicopathologic abnormalities were normocytic, normochromic anemia; hypoalbuminemia; azotemia; hypercholesterolemia; proteinuria; and urine specific gravity values below the normal range. Histologic examination of renal tissue from the 6 Beagles revealed moderate to severe glomerular amyloidosis with inconsistently observed mild medullary interstitial amyloidosis. Congo red-stained kidney sections from 4 of 4 affected dogs were potassium permanganate-sensitive, suggestive of reactive amyloidosis. Hereditary predisposition for renal amyloidosis was suspected in these Beagles.

Amyloidosis↗
PubMed1992

Co-migrating and shared antigens of selected Pasteurella haemolytica untypable strains.

Bacterial cell envelope preparations from eight untypable strains of Pasteurella haemolytica were compared by sodium dodecyl sulphate-polyacrylamide gel electrophoresis and immunoblotting with rabbit antisera prepared against the eight untypable strains (one untypable strain per rabbit) and with cattle antisera prepared against P. haemolytica serotypes 1, 2, 5, 6, 9 and against one heterologous untypable strain. Numerous comigrating and shared antigens were recognized by the eight rabbit antisera and the P. haemolytica serotype cattle antisera. Comigrating antigens at 43 and 30 kilodaltons (kDa) were recognized by all eight rabbit antisera. Shared antigens, detected by all eight rabbit antisera when reacting against P. haemolytica serotype 1, were recognized at 43, 32, 30, 20 and 15 kDa.

Animals↗
PubMed1992

Cryptosporidiosis in adult and neonatal mice with severe combined immunodeficiency.

Cryptosporidium parvum causes protracted diarrhoea in immunodeficient hosts. To characterize the role that T and B lymphocytes play in the eradication of the parasite from the intestinal mucosa, the course of infection in mice with severe combined immunodeficiency (SCID) was studied. Twenty-nine SCID and 26 BALB/c adult mice received 10(6) oocysts intragastrically. The course of infection in the two strains was similar until 2 months after inoculation, when moderate numbers of organisms were identified in the villous and crypt mucosa of the ileum and proximal colon of SCID mice. Three months after inoculation, SCID mice developed wasting and progressive intestinal and biliary tract disease. At 5 months, mortality of 72 and 0 per cent, respectively, was observed in the SCID and BALB/c mice. Twenty-four SCID and 26 BALB/c neonatal mice were also inoculated with C. parvum. Cryptosporidiosis occurred in SCID and BALB/c mice within 2 weeks of inoculation. Subsequently, BALB/c, but not SCID mice, eradicated the parasite from their intestinal mucosa. SCID mice developed progressively severe cryptosporidiosis which killed all animals within 7 weeks. Responses mediated by B or T cells, or both, appeared to play a role in eradicating C. parvum from the intestinal mucosa, since SCID mice were more severely affected than BALB/c mice. The different course of infection in adult and neonatal SCID mice indicated that other age-related factors also played a role in containing C. parvum infection.

Animals↗
PubMed1992

Bovine humoral immune response to Cryptosporidium parvum.

Cryptosporidiosis is a diarrheal disease predominantly affecting cattle and humans. Sera from experimentally infected calves and calves of various ages with no histories of exposure were evaluated for immunoglobulin G to Cryptosporidium parvum. An age-associated increase in immunoglobulin G was present in experimental calves and in calves with no histories of infection from 1 to 3, but not > 3, months of age.

Age Factors↗
PubMed1992

Hairy vetch (Vicia villosa Roth) poisoning in cattle: update and experimental induction of disease.

Hairy vetch poisoning (vetch-associated disease) of cattle is a generalized disease characterized pathologically by infiltration of skin and many internal organs by monocytes, lymphocytes, plasma cells, and often eosinophils and multinucleated giant cells and clinically by dermatitis, pruritus, often diarrhea, wasting, and high mortality. The disease was experimentally reproduced in an adult Angus female that had recovered from the natural disease 1 year earlier. She developed dermatitis on the 11th day of vetch feeding, and despite withdrawal from the vetch diet on the 12th day, death occurred 24 days after first day of vetch feeding. The cow developed lymphocytosis and hyperproteinemia. The results of other hematologic evaluations, blood chemical profiles, urinalysis, and cutaneous hypersensitivity tests using vetch lectin were normal. Lymphocyte blastogenesis studies with vetch lectin were not interpretable. Necropsy revealed gross lesions characteristic of the disease in the skin, heart, kidney, adrenal, and lymphoid tissues. Microscopically there was typical cellular infiltration in those organs and in the thyroid, liver, pancreas, salivary and mammary glands, urinary bladder, corpus luteum, and cerebral meninges. Cutaneous apocrine gland necrosis was present. The inflammatory reaction has qualities of a type-IV hypersensitivity reaction. Hypersensitivity may occur when constituents of the ingested plant are absorbed and act as antigens that sensitize lymphocytes and evoke the multisystemic granulomatous inflammatory response that characterizes the disease. Alternatively, vetch lectin may directly activate T lymphocytes to initiate the cellular response. Vetch-like diseases have been associated with a variety of diets that did not contain hairy vetch.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenal Glands↗
PubMed1991

Multisystemic granulomatous inflammation in a horse.

A one-year-old Thoroughbred filly was examined because of poor body condition and reluctance to move its neck. Complete blood count revealed leukocytosis (15,700 WBC/microliters) and hyperproteinemia (8 g/dl). Radiography of the cervical vertebrae revealed multifocal lesions of bone lysis surrounded by zones of sclerosis. The horse was euthanatized and necropsied. Granulomatous lesions were identified in the heart, spleen, lungs, bones, and lymph nodes. The multifocal granulomatous inflammatory lesions in this horse were suggestive of mycobacteriosis.

Animals↗
PubMed1990

Molecular aspects of virulence of Pasteurella haemolytica.

Pasteurella haemolytica is represented by two biotypes (A and T), 15 serotypes, and numerous untypable strains. Specific biotypes and serotypes are associated with fibrinous pleuropneumonia (pneumonic pasteurellosis) in cattle, sheep, and goats, septicemic pasteurellosis in lambs, and mastitis in ewes. Four virulence factors have been associated with P. haemolytica: fimbriae, a polysaccharide capsule, endotoxin [lipopolysaccharide (LPS)], and leukotoxin (LKT). The interactions of these virulence factors with components of the pulmonary alveolus are discussed as a model for the pathogenesis of pasteurellosis. Fimbriae on P. haemolytica may enhance colonization of the upper respiratory tract. The capsule of P. haemolytica varies in composition among serotypes. It inhibits complement-mediated serum killing as well as phagocytosis and intracellular killing of P. haemolytica. The capsule enhances neutrophil directed migration and adhesion of P. haemolytica to alveolar epithelium. Pasteurella haemolytica LPS can alter bovine leukocyte functions, by dose-dependent inhibition or augmentation; it is directly toxic to bovine endothelium; it modifies cardiopulmonary hemodynamics; and it elevates circulatory prostanoids, serotonin, cAMP, and cGMP. Leukotoxin is produced by all known serotypes and many untypable strains. Leukotoxin is a poreforming cytolysin that affects ruminant leukocytes and platelets by altering function at low levels but causing lysis at high levels.

Animals↗
PubMed1990

Pasteurella haemolytica lipopolysaccharide-induced arachidonic acid release from and neutrophil adherence to bovine pulmonary artery endothelial cells.

Bovine pulmonary artery endothelial cells (BPAEC) were labeled with 3H-arachidonic acid. Exposure of the labeled BPAEC to Pasteurella haemolytica lipopolysaccharide (LPS) resulted in a time- and dose-dependent release of radioactivity. The release was inhibited by 5 mM indomethacin, but inhibition was not caused by less than or equal to 500 microM indomethacin or hydrocortisone, which suggests that the release was caused primarily by a mechanism other than cyclooxygenase or phospholipase A2 metabolism of arachidonic acid. Pasteurella haemolytica LPS also caused increased adherence of bovine neutrophils to BPAEC through independent effects on both cell types. The increased adherence was inhibited by treatment of either cell type with cycloheximide or actinomycin D prior to LPS exposure, indicating that de novo protein synthesis was required in both cell types to promote the LPS-induced adherence. Lipopolysaccharide may be an important factor in neutrophil-mediated effects in pneumonic pasteurellosis by causing increased neutrophil adherence and, thus, the vascular sequestration of neutrophils. Together, these experiments provide additional evidence for the involvement of LPS in pneumonic pasteurellosis. Moreover, they provide evidence of LPS-induced endothelial activation, which could have broad ramifications in the inflammatory and immune responses of pneumonic pasteurellosis.

Animals↗