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In two studies with 50 male and 50 female undergraduates, differences in learning highly interfering paired-associate discrimination tasks were compared with or without visual mediational cues and with aural cues only. Visual mediational instruction reduced interference between similar signals and facilitated their association with the correct symbol. (SLD)

Oral immunization with 25 mg/day of ovalbumin resulted in a number of changes in non-specific immune responsiveness, including increases in antibody produced to T-dependent but not T-independent antigens and the abrogation of tolerance induced by both oral and intravenous routes. The effect was transient, sex- and strain-dependent. Evidence suggests that it is a consequence of cell-mediated immunity to the oral immunogen. [ABSTRACT FROM AUTHOR]

We report a girl with severe combined immunodeficiency with functional impairměnt of both humoral and cellular immunity despite normal numbers of B and T lymphocytes. Immunologic studies revealed hypergammaglobulinaemia, absent migratory response by polymorphonuclear leucocytes to chemoattractants, and diminished lymphocyte proliferative responses to mitogens, antigens and allogeneic leucocytes. However, stimulation of the patient's mononuclear leucocytes with the calcium ionophore, A23187, resulted in a normal proliferative response. We therefore postulate a membrane defect as the basis for immunologic dysfunction in this child. [ABSTRACT FROM AUTHOR]

The introduction of 25 mg of a new protein antigen into the diets of mice produced transient increases in PVP clearance which reached a maximum 60 hr after the change of diet and had disappeared by 4 days. At the same time the immune responsiveness to unrelated antigens given parenterally was also raised transiently, reaching a peak 5 days following the change and disappearing by 7 days. In contrast the responsiveness to the fed antigen was diminished. [ABSTRACT FROM AUTHOR]

The effect of feeding the B-cell mitogens Escherichia coli lipopolysaccharide and dextran sulphate on the development of orally induced tolerance to the contact sensitizing agent picryl chloride was studied in mice. Feeding either agent throughout the experiment or during tolerization, increased the tolerizing effect of a single feed of picryl chloride. [ABSTRACT FROM AUTHOR]

The secretory and systemic antibody responses to oral dead Escherichia coli were examined in A strain mice. The best responses were obtained in mice dosed with 1 x 1010 bacteria. Orally immunized animals showed an enhanced response to subsequent parenteral immunization with somatic antigens. This effect could be passively transferred with serum In contrast, the response to the capsular antigen K88 was reduced in the same animals. [ABSTRACT FROM AUTHOR]

The immune response of pigs to oral immunization with dinitrophenylated bovine gamma globulin (DNP-BGG) was assessed using the indirect macrophage migration assay. Two days' exposure to the antigen resulted in the inhibition of macrophage migration by supernatants of cultures from the intestine but not the mesenteric lymph node or spleen. Stimulation for 7 days resulted in macrophage inhibition by supernatants of lymphocyte cultures prepared from the intestine, mesenteric lymph node and spleen. Supernatants of splenic lymphocytes from animals stimulated for 2 or 3 days produced enhancement of macrophage migration. [ABSTRACT FROM AUTHOR]

The immunoglobulin content of porcine nasal, tracheal and bronchio-alveotar secretions was determined. IgA was the predominant immunoglobulin in nasal and tracheal secretions, there being no significant difference (P>0·1) between their IgA:IgG ratios of 2·7:1 and 2·4:1,respectively. In contrast, IgG was the predominant immunoglobulin in bronchioalveolar secretions, the IgA:IgG ratio being 0·7:1. The ability of tracheal and lung tissue to synthesize IgA and IgG was determined in vitro, Tracheal cultures synthesized more IgA than IgG whereas in the lungs the reverse occurred, the ratio of IgA: IgG synthesis being 1·4:1 and 0·4:1, respectively. The proportion of serum-derived IgA and IgG in respiratory tract secretions was determined by measuring the transfer of 125I - and 131I-labelled immunoglobulins from serum. It appeared that more than 97% of the IgA was produced locally. More significantly a proportion of the IgG was also synthesized locally. This proportion was smallest in nasal secretions (21·8%) and greatest in bronchio-alveolar secretions (62·6%). The results suggest that IgG, a large proportion of which is locally synthesized, is important in the homeostatic mechanisms of the lower respiratory tract. [ABSTRACT FROM AUTHOR]

Oral immunization of the lactating sow with live Escherichia coli (O8:K88) stimulated an IgA anti-K88 antibody response in mammary secretions und significantly enhanced the capacity of whey to inhibit adhesion of the inoculum E. coli strain to isolated pig enterocytes. An increase in agglutinating unti-O8 activity was also evident in milk and was associated with both the IgA and IgM immunoglobulin classes. These results are consistent with the concept of a gut mammary link, although measurement of specific antibody in the intestinal secretions of these animals suggested that there may he a difference in response duration at the two secretory sites. Prolonged oral administration of heat-killed organisms also stimulated specific antibody synthesis within the mammary gland, although the response, particularly to the O antigen, was both reduced und delayed in its appearance. [ABSTRACT FROM AUTHOR]

A nonclinical study was conducted to characterize the replication behavior of a modified live gE-deleted pseudorabies virus (PRV MS+1) in swine and potential for reversion to virulence after animal passages. Two to 3 week-old weaned pigs, negative for PRV, were maintained in isolation and challenged by intranasal instillation. For the first passage, 6 pigs were given 1 mL of PRV MS+1 (10(7.3)TCID(50)/mL) and 2 were necropsied at 3, 4 and 5 days post-inoculation (PI). Brain and secondary lymphoid tissues were collected, homogenized and the supernatants individually pooled for virus isolation, and PRV was recovered from each sample. No clinical signs of PRV infection were observed, but each pig had a nasal swab suspect or positive for PRV. For the second passage, 5 pigs were given 1 mL of the homogenate of mixed tissues from 1 animal in the previous passage (PRV at 10(1.9) TCID(50)/mL). At 5 days PI, all pigs were necropsied, and PRV was not recovered from their tissue homogenates or nasal swabs, and no clinical signs were observed. During a second attempt at a second passage, tissue homogenates from all pigs in the first passage (PRV at approximately 10(1.7)TCID50(50)/mL) were pooled and used to inoculate 15 pigs with 2 mL for 3 consecutive days. Ten pigs were monitored for clinical signs and seroconversion through 21 days PI, and 5 pigs were necropsied at 5 days PI. No clinical signs or PRV antibodies were detected in the 10 monitored pigs, and no PRV was recovered from the homogenates or nasal swabs of the 5 necropsied pigs. Thus, no evidence of reversion to virulence was demonstrated in pigs given the attenuated PRV.

Calves were inoculated with the bovine herpes virus 1 (BHV-1) vaccine strain (RLB 106), which is a temperature sensitive mutant. The route of inoculation was intranasal instillation or intramuscular (i.m.) injection (flank or neck). As a control, five calves were given placebo by i.m. injection of the neck. Regardless of the infection route, clinical symptoms did not occur. However, BHV-1 neutralizing antibodies were detected after inoculation demonstrating that sero-conversion occurred. At 60 days post-inoculation, dexamethasone was given by i.m. injection to attempt reactivation of RLB 106. Only those calves inoculated by the intranasal route shed virus leading to an increase in BHV-1 specific antibodies. As expected, viral DNA and the latency related-RNA were detected in trigeminal ganglia (TG) of calves inoculated by the intranasal route. In contrast, viral nucleic acid was not detected in TG of calves inoculated by the i.m. route or in calves inoculated with placebo. In cervical ganglia or sacral dorsal root ganglia, viral nucleic acid was not consistently detected. This study provides evidence that efficient latency and reactivation does not occur following i.m. inoculation. Since serum-neutralizing antibodies were detected in all inoculated calves, i.m. inoculation led to sero-conversion.

Four trials were conducted to study synchronous estrous response in beef cows and in beef and dairy heifers to Luprostiol (13, thia-PG-F(2)alpha analog) in comparison with other prostaglandin products. In Trial 1, 60 virgin beef heifers were observed for estrus for 5 d and artificially inseminated. Heifers not observed in estrus within 5 d were randomly assigned to receive 15 mg Luprostiol or 25 mg Lutalyse. In Trial 2, 75 multiparous, lactating beef cows were randomly assigned to receive either 15 mg Luprostiol, 25 mg Lutalyse or 500 mcg Estrumate. All cows received a second injection of the respective treatment 11 d later. In Trial 3, 96 multiparous, lactating beef cows were randomly assigned to receive 15 mg Luprostiol or 25 mg Lutalyse. All cows received a second injection of the respective treatment 11 d later. In Trial 4, virgin dairy heifers were palpated per rectum. Seventy-seven heifers with a palpable corpus luteum (CL) were randomly assigned to receive 15 mg Luprostiol or 500 mcg Estrumate. In all trials animals were artificially inseminated 12 h following observed estrus. Estrous response during the 5-d synchronized period was 44% for Luprostiol and 42% for Lutalyse treated heifers in Trial 1. It was 52, 56 and 60%, respectively, for Luprostiol, Lutalyse and Estrumate treated cows in Trial 2; 23% for Luprostiol and 19% for Lutalyse treated cows in Trial 3; and 68% for Luprostiol and 70% for Estrumate treated heifers in Trial 4. Treatment with Luprostiol results in a similar synchronous estrous response as with the other prostaglandin products used in these studies.

Infective 3rd-stage larvae of Ostertagia and Cooperia, obtained from the feces of nonmedicated and morantel sustained-release bolus (MSRB)-treated calves, were orally administered to 2 groups of parasite-free calves. After a 42-day maturation period, a therapeutic dose of morantel tartrate was administered to half of the calves from each group. All calves were necropsied 7 days after treatment. After comparing the nematode counts for the nonmedicated and morantel-treated calves of each group, morantel tartrate was demonstrated to be equally effective against the nonmedicated-derived and MSRB-derived nematode populations. The sensitivity of Ostertagia spp and Cooperia spp to morantel tartrate, therefore, was not diminished after use of the MSRB for a single grazing season.

Twenty-two cases of feline glomerulonephritis were investigated for the presence of immune complexes within the glomerulus using the peroxidase-antiperoxidase (PAP) method. This method was used with formalin-fixed paraffin-wax embedded tissues which were pretreated with trypsin and with frozen sections of kidney tissue. Of a total of 25 kidney specimens examined (two cats had repeated biopsies) the composition of the deposits was 23/25 IgG, 17/25 C3, 11/25 IgM and 2/25 IgA. Serial studies of two cats showed a progression of the disease from initial nephrotic syndrome to chronic renal failure. With the more severe form of the disease there was a tendency for the deposition of complement and more than one class of immunoglobulin within the glomeruli.

Intranasal vaccination with a cold-adapted strain of feline herpesvirus type 1 (FHV-1) two days before challenge gave partial protection, and four days before challenge gave complete protection, against feline viral rhinotracheitis. Protection at this time appeared to be specific since vaccination with FHV-1 did not affect the disease caused by the unrelated feline calicivirus. The time course of onset of protection also confirmed that the protective mechanism was likely to be specific. However, six days after vaccination only low levels of FHV-specific IgA and IgM antibody and of interferon were found in serum and nasal washings. In lymphocyte transformation assays neither peripheral blood lymphocytes nor tonsil lymphocytes gave a significant proliferative response in the presence of FHV antigen. Pathogenesis experiments demonstrated that the tonsil and nasal turbinates were the most important sites of virulent FHV-1 replication. Vaccination significantly reduced levels of infectious virus found in both sites. The results provide evidence that no one mechanism is responsible for protection following vaccination but local specific responses are more likely to be involved.

The morphology and some of the in vitro functional properties of the cells in the mammary secretions of sows have been examined. A mean cell yield of 1 x 10(7) cells/ml was obtained from sow colostrum but during the first week post-partum the yield decreased approximately 10 fold. The polymorphonuclear leucocyte was the predominant cell type in colostrum and milk and was associated with varying proportions of lymphocytes, macrophages and epithelial cells. The phagocytes of sow milk ingested heat-killed yeast, although the phagocytic index for milk macrophages was low compared with autologous neutrophils and alveolar macrophages. Milk whey provided an effective opsonising medium for yeast ingestion. Intra-mammary immunisation of sows with ovalbumin induced antigen-reactive lymphocytes in both peripheral blood and milk.

Food was given to pigs before weaning to determine whether a hypersensitive response to dietary antigen might be a predisposing factor to postweaning diarrhea. Small amounts of food increased the severity and accelerated the onset of postweaning diarrhea. Postweaning diarrhea was dependent on the presence within the diet of antigenic material (bovine casein). A weaning diet, containing little antigenic material (hydrolyzed casein), had less effect on sucrase concentration in intestinal brush borders than did diets rich in antigens (native casein). Seemingly, immune-mediated intestinal damage may predispose the pig to postweaning diarrhea.

The origin of the immunoglobulins of bovine colostrum and milk were examined by using radiolabeled protein. Colostrum was found to consist mainly of immunoglobulin derived from serum, although there was some local synthesis. In lactation the immunoglobulins of milk were almost entirely serum derived. The local immune system was very inactive but could be stimulated to activity by local immunization. The immunoglobulin profiles of the secretion from the stimulated gland were still relatively deficient in IgA compared to other species, notably the pig.

An antibody assay is described based on the principle of complement mediated lysis of sheep red blood cells labelled with antigen. The technique provides a sensitive class specific assay enabling antibody in all three major immunoglobulin classes to be quantitated independently. The assay may be performed in tubes allowing precise measurement of antibody concentration, or in microtitre plates which provides a rapid estimation of antibody titre.

The immune response of pigs fed 200 mg per day of dinitrophenylated bovine gamma globulin has been evaluated in terms of the antibody and lymphocyte responses and of the induction of tolerance and immune exclusion. Although dosing for ten days resulted in a small IgA response as indicated by splenic plaque forming cells, serum antibody could only be detected when dosing was continued for 42 days. secretory antibody was detected at any time. Antigen feeding for two weeks rendered the animals hyporesponsive to subsequent parenteral antigenic challenge but had little effect upon their ability to exclude an oral dose of antigen from the circulation.

Nine mares received cannulae to collect blood from the pituitary venous outflow in the intercavernous sinus (ICS) and the jugular vein; in 4 mares, only jugular cannulae were used. Those 4 mares and 3 of the mares with cannulae in both positions received 7.5 mg luprostiol i.m. and 1 mare with both cannulae was treated with 3.75 mg uprostiol i.v. Blood samples were kept before and after treatment at 2-, 5- or 10-min intervals and concentrations of LH, FSH and GnRH were determined by RIA. Treatments resulted in an immediate sharp rise of LH and FSH in ICS and jugular blood samples within 2-10 min, with ICS concentrations rising earlier, and with peak levels of LH 8 to 100 times higher, respectively. In ICS samples, GnRH was elevated consistently only after LH and FSH had reached peak levels. At both locations, LH and FSH concentrations remained elevated 60-120 min after treatment, but had returned to baseline by 240 min. In 5 untreated mares with cannulae at both locations, sampling at 5-min intervals for 12 or 24h revealed no pulses of LH or FSH in 3 mares, and only one pulse a day, preceded by several small rises of GnRH during the hour before the pulses, in 2 mares.

In an examination of the immunoglobulins of the small intestine of calve, IgG1 was the major immunoglobulin in the secretions, and IgA was present in smaller amounts. Immunohistochemical studies showed few IgA containing plasma cells but many cells that stained with anti-IgG antiserum. Histological evidence of transport of IgG1 across the crypt epithelial cell was found. Studies with 125I-labelled IgG1 indicated that a significant proportion of IgG1 in the intestine originated in serum.

Five-day-old pigs challenged with 10(3) pathogenic Escherichia coli (nalidixic acid resistant) showed no clinical signs of disease until subsequently weaned at three weeks. Dietary manipulation was shown to influence xylose malabsorption, diarrhoea and bacterial proliferation after weaning. Brief, but not continuous, contact with the diet before weaning markedly increased the severity of subsequent disease after weaning. Immunogenicity of the weaning diet was critical for the development of the disease. Two diets, identical except that in one the protein source (casein) had previously been enzymatically hydrolysed, were compared. Pigs fed the predigested diet showed no clinical signs of post weaning diarrhoea whereas those fed the untreated casein all developed diarrhoea.

Two groups of 10 parasite-free calves were maintained either for 2 weeks on a pasture grazed by nonmedicated cattle (pasture A) or for 3 weeks on a pasture grazed by morantel sustained-release bolus-treated cattle (pasture B) for the preceding 2 years. After a 4-week holding period to allow for maturation of acquired gastrointestinal nematodes, 5 calves from each group were administered a therapeutic dose (10 mg/kg of body weight) of morantel tartrate. All calves were necropsied 1 week later, and the abomasal and small intestinal nematodes were isolated, identified, and enumerated. A comparison of efficacies between nonmedicated and morantel tartrate-treated calves of each pasture demonstrated that morantel was equally effective against the gastrointestinal nematode infections, regardless of infection source (ie, pasture A vs pasture B). The overall nematode reductions due to morantel tartrate treatment of calves that grazed pastures A and B were 98% and 96%, respectively. It was concluded that the sensitivity of gastrointestinal nematodes to morantel tartrate was not diminished in calves maintained on pasture B, which had been stocked with morantel sustained-release bolus-treated calves for the preceding 2 grazing seasons.

Four injections of a long-acting oxytetracycline (20 mg/kg) were administered at 3-day intervals to 14 naturally infected anaplasmosis carrier cattle. Individual anaplasma serology titers were evaluated, using complement-fixation and rapid card-agglutination tests at frequent intervals during a 180-day posttreatment period. Serologic results indicated fluctuating complement-fixation titers during the trial period. However, at trial termination, 12 of 14 animals were negative by complement-fixation testing and all animals were card-test negative. Eight splenectomized calves given 10 ml of blood from the medicated cows at their posttreatment day 150 failed to manifest any clinical, hematologic, or serologic signs of anaplasmosis during 56 days. Susceptibility to anaplasmosis challenge exposure was demonstrated by positive clinical and serotest reactions when 3 of the recipient calves were inoculated with blood from a parasitemic carrier calf.

The efficacy of using a bolus containing morantel in a sustained-release preparation for controlling naturally acquired gastrointestinal parasitic infections in weaned calves and yearling cattle was investigated during the 1982 grazing season at selected sites in the United States and Canada. According to a common trial design under various climatic and management conditions, 10 field trials were conducted with the bolus. At the time of spring turnout, a bolus was administered to each calf or yearling in the treated group. Then, treated and control cattle grazed separate but equal areas of divided pasture(s). The epidemiologic pattern of parasitic gastroenteritis in control animals and the effect of treatment on this pattern was determined in each trial. Safety and practicality of use of the bolus also were established. When compared with untreated cattle (control), those given the bolus deposited significantly (P less than 0.05) fewer worm eggs (89% reduction) during the first 90 days of the grazing season, as well as significantly fewer (P less than 0.05) worm eggs (84% reduction) during the entire grazing season. Consequently, during the second half of the grazing season, larval populations on treated pastures remained significantly (P less than 0.05) lower (66% reduction), compared with numbers of larvae found on control pastures. For pastures grazed by treated and control cattle at trial initiation, mean worm counts recovered from tracer calves were equal, indicating comparable pasture contamination at the beginning of the grazing season.(ABSTRACT TRUNCATED AT 250 WORDS)

Immunoglobulin quantitation of fluids obtained from several regions of the female reproductive tract indicated the presence of IgG, IgA and IgM. IgG was almost invariably present in greatest amounts and IgM always made the smallest contribution. Although much of this immunoglobulin was derived from serum, evidence of the molecular size of IgA, the IgA and IgG ratios and that obtained from experiments involving the injection into sows of 125I-labelled immunoglobulin indicated that local synthesis within the tract also occurred.

The efficacy of a morantel sustained release bolus (MSRB) for control of gastrointestinal nematodes in yearling steers was evaluated over a 6-month grazing period commencing on 26 March 1982. Three groups of 15 steers were allotted to the following treatments: Group 1 -- one MSRB at start of trial; Group 2 -- one therapeutic dose of thiabendazole at start of trial; Group 3 -- untreated control. The treatment groups were grazed separately. Parasite egg counts (EPG), herbage larval counts, pepsinogen levels and weight gains were monitored. Every other month, sets of 2 parasite-free tracer calves were placed in the pasture grazed by each treatment group and allowed to graze for 3 weeks before being subsequently necropsied for worm counts. At the end of the trial, 6 animals from each group were also necropsied for worm counts. The MSRB treatment resulted in significantly lower egg counts, fewer infective larvae on pasture, lower pepsinogen levels and lower worm burdens in tracer calves than was the case for the untreated group, but generally the levels were not significantly different from those associated with the thiabendazole treatment. The mean weight gain for the MSRB treated steers showed a significant advantage (70.9 lb) over the untreated animals, but was not significantly different from those which received thiabendazole. Total worm counts at the end of the trial were not different from any treatment group.