Major histocompatibility (B) complex control of responses against Rous sarcomas

The chicken major histocompatibility (B) complex (MHC) affects disease outcome significantly. One of the best characterized systems of MHC control is the response to the oncogenic retrovirus, Rous sarcoma virus (RSV). Genetic selection altered the tumor growth pattern, either regressively or progressively, with the data suggesting control by one or a few loci. Particular MHC genotypes determine RSV tumor regression or progression indicating the crucial B complex role in Rous sarcoma outcome. Analysis of inbred lines, their crosses, congenic lines, and noninbred populations has revealed the anti-RSV response of many B complex haplotypes. Tumor growth disparity among lines identical at the MHC but differing in their background genes suggested a non-MHC gene contribution to tumor fate. Genetic complementation in tumor growth has also been demonstrated for MHC and non-MHC genes. RSV tumor expansion reflects both tumor cell proliferation and viral replication generating new tumor cells. In addition, the B complex controls tumor growth induced by a subviral DNA construct encoding only the RSV v-src oncogene. Immunity to subsequent tumors and metastasis also exhibit MHC control. Genotypes that regressed either RSV or v-src DNA primary tumors had enhanced protection against subsequent homologous challenge. Regressor B genotypes had lower tumor metastasis compared with progressor types. Together, the data indicate that B complex control of RSV tumor fate is strongly defined by the response to a v-src-determined function. Differential RSV tumor outcomes among various B genotypes may include immune recognition of a tumor-specific antigen or immune system influences on viral replication.

Resistance, susceptibility, and immunity to cecal coccidiosis: effects of B complex and alloantigen system L

This study examined alloantigen system L effects on resistance to initial infection and acquired immunity to Eimeria tenella infection in three B complex genotypes. Experimental progeny segregating for B and L genotypes were produced from pedigree matings of B2B5 L1L2 sires and dams. Chicks were weighed and inoculated with 30,000 E. tenella oocysts at 6 wk of age to evaluate resistance in four trials (n = 262). Immunity was studied in four additional trials (n = 244) by immunizing progeny with 500 E. tenella oocysts per day for 5 d beginning at 5 wk of age. Two weeks after the last immunization dose, the birds were weighed and challenged with 30,000 E. tenella oocysts. All birds were weighed again and scored for cecal lesion 6 d after the 30,000 oocyst dose challenge. Weight gain and cecal lesion scores were evaluated by ANOVA. Major histocompatibility (B) complex genotypes B2B2 and B5B5 did not affect resistance to initial challenge with E. tenella based on lesion score and weight gain. However, after immunization, the B5B5 and B2B5 genotypes had significantly lower cecal scores than the B2B2 genotype when the birds were rechallenged. Weight gain was not affected among immunized birds. No significant L system effects with or without immunization were detected. These results are consistent with previous research demonstrating B complex effects on immunity to cecal coccidiosis.

The effect of resin/crosslinker ratio on the mechanical properties and fungal deterioration of a maxillofacial silicone elastomer

Variation of the crosslinker/resin ratio of a room temperature condensation cure maxillofacial silicone elastomer has caused considerable changes in the mechanical properties and deterioration by Candida albicans. Increasing the crosslinker/resin ratio caused a decrease in the tensile strength and stiffness of the elastomer. However, tear strength appeared to show an optimum value at the recommended crosslinker/resin ratio. These effects were due to the low molar mass silicone polymer that acts as a carrier for the actual crosslinking additive. The general decrease in mechanical properties was accompanied by an increase in the hexane extractables content and an increase in the Si-H content of the elastomer. The unbound polymer (extractable material) content of the elastomer was found to influence the colonization of the material by C. albicans. An increase in the unbound polymer content corresponded to an increasing number of hyphae and blastospores observed penetrating into the elastomer. The data obtained in this study have significant implications concerning the degree of control of elastomer formulation and the deterioration of maxillofacial appliances.

Susceptibility to spontaneous atherosclerosis in pigeons: an autosomal recessive trait

The inheritance pattern for susceptibility to spontaneous (noninduced) aortic atherosclerosis in pigeons was determined by crossbreeding and backcrossing experiments with atherosclerosis-susceptible White Carneau and atherosclerosis-resistant Show Racer breeds. Susceptibility, assessed by the presence of grossly visible lesions at the celiac bifurcation of the aorta at 3 years of age, demonstrated an inheritance pattern consistent with an autosomal recessive Mendelian trait. Cell culture studies indicated that susceptibility is a constitutive property of aortic cells as evidenced by vacuole formation and lipid content in smooth muscle cells from various tissues in susceptible pigeons.

Allelic complementation between MHC haplotypes B(Q) and B17 increases regression of Rous sarcomas

Major histocompatibility (B) complex haplotypes B(Q) and B17 were examined for their effect on Rous sarcoma outcome. Pedigree matings of B(Q)B17 chickens from the second backcross generation (BC2) of Line UCD 001 (B(Q)B(Q)) mated to Line UCD 003 (B17B17) produced progeny with genotypes B(Q)B(Q), B(Q)B17, and B17B17. Six-week-old chickens were injected with subgroup A Rous sarcoma virus (RSV). The tumors were scored for size at 2, 3, 4, 6, 8, and 10 weeks postinoculation. A tumor profile index (TPI) was assigned to each bird based on the six tumor scores. Two experiments with two trials each were conducted. In Experiment 1, chickens (n = 84) were inoculated with 30 pock-forming units (pfu) RSV. There was no significant B genotype effect on tumor growth over time or TPI among the 70 chickens that developed tumors. Chickens (n = 141) were injected with 15 PFU RSV in Experiment 2. The B genotype significantly affected tumor growth pattern over time in the 79 chickens with sarcomas. The B(Q)B17 chickens had the lowest TPI, which was significantly different from B17B17 but not B(Q)B(Q). The data indicate complementation because more tumor regression occurs in the B(Q)B17 heterozygote than in either B(Q)B(Q) or B17B17 genotypes at a 15 pfu RSV dose and significantly so compared to B17B17. By contrast, the 30 pfu RSV dose utilized in the first experiment overwhelmed all genotypic combinations of the B(Q) and B17 haplotypes, suggesting that certain MHC genotypes affect the immune response under modest levels of viral challenge.

Nonmajor histocompatibility complex alloantigen effects on the fate of Rous sarcomas

Rous sarcoma virus-induced tumor outcome is controlled by the MHC (B). Additional data, using controlled segregation in families, has indicated non-MHC effects as well, but few studies have focused on blood groups other than the B complex. Segregating combinations of genes encoding erythrocyte (Ea) alloantigen systems A, C, D, E, H, I, P, and L in B2B5 and B5B5 MHC (B) backgrounds were examined for their effects on Rous sarcomas. Six-week-old chickens were inoculated in the wing-web with 30 pfu of Rous sarcoma virus (RSV). Tumors were scored six times over a 10-wk period. A tumor profile index (TPI) was assigned to each chicken based on the six tumor size scores. Response was evaluated using tumor size at each measurement period, TPI, and mortality. The genotypes of Ea systems A, C, D, E, H, I, and P had no significant effect on any parameter in either B complex population. The Ea-L system had an effect on Rous sarcomas in the B2B5 intermediate responders and B5B5 progressors. Tumor size, TPI, and mortality were all significantly lower in B2B5 L1L1 chickens than in B2B5 L1L2 chickens. Mortality was lower in the B5B5 L1L1 birds than in B5B5 L1L2 chickens. It appears that the Ea-L system, or one closely linked, is acting in a manner independent of the B complex in response to RSV challenge.

Decreased cerebral emboli during distal aortic arch cannulation: a randomized clinical trial

BACKGROUND

Cerebral emboli occur during cardiopulmonary bypass and are a principal cause of postoperative neurologic dysfunction. We hypothesized that arterial cannulation of the distal aortic arch, with placement of the cannula tip beyond the left subclavian artery, will result in fewer cerebral microemboli than conventional cannulation of the ascending aorta.

METHODS

Patients undergoing coronary bypass surgery with a single crossclamp technique were randomized to receive cannulation of the distal aortic arch (n = 17) or standard cannulation of the ascending aorta (control group, n = 17). Trendelenburg positioning was used whenever possible. Cerebral emboli were quantified by continuous transcranial Doppler monitoring of the middle cerebral artery.

RESULTS

Baseline demographics were similar for the 2 groups of patients, including cardiopulmonary bypass and crossclamp times. Cerebral microemboli were detected during cardiopulmonary bypass in all patients, with a range of 17 to 627 emboli. The total number of detected emboli was lower in the arch cannulation group (152 +/- 33, mean +/- standard error of the mean) than in the conventional cannulation group (249 +/- 35, P =.04). Embolization rates were lower in distal arch patients than in control patients during cardiopulmonary bypass (2.0 +/- 0.3 vs 4.2 +/- 0.9 per minute, respectively, P =.03). Reduction in cerebral emboli by distal arch cannulation was most pronounced during perfusionist interventions.

CONCLUSIONS

Cannulation of the distal aortic arch results in less cerebral microembolism than conventional cannulation of the ascending aorta. Provided it is performed safely, distal arch cannulation may be an important surgical option for patients with severe atherosclerosis of the ascending aorta.

Cerebral microemboli during cardiopulmonary bypass: increased emboli during perfusionist interventions

BACKGROUND

Microemboli to the cerebral circulation occur during cardiopulmonary bypass (CPB) and can contribute to postoperative neurologic dysfunction. Cerebral microemboli are known to occur during specific surgical interventions, but the source of a large proportion of emboli remains unexplained. We investigated whether interventions by the perfusionist could account for the appearance of cerebral microemboli.

METHODS

Transcranial Doppler ultrasonography was used to continuously monitor the middle cerebral artery of 18 patients undergoing coronary artery bypass grafting. The CPB circuit consisted of a softshell venous reservoir, a hollow-fiber membrane oxygenator, and a 32-microm arterial filter. The mean embolic rate was calculated for three time periods: (1) during surgical interventions (aortic cannulation and decannulation, cross-clamp application and removal, CPB start and end, and start of cardiac ejection); (2) during perfusionist interventions (blood sampling and drug administration into the venous reservoir); and (3) during baseline (all other time periods during CPB).

RESULTS

Microemboli were detected in all patients (mean +/- standard deviation, 207+/-142 per patient, median, 132). The number of emboli per minute was significantly (p < 0.001) higher during perfusionist interventions (6.9+/-4.5) than during surgical interventions (1.5+/-1.5) or during baseline (0.4+/-0.5). Drug administration resulted in a higher embolic rate than blood sampling.

CONCLUSIONS

Interventions by the perfusionist account for a large proportion of previously unexplained cerebral microemboli during CPB. These emboli likely represent air bubbles that are not eliminated by the arterial line filter. Although further studies of additional types of CPB circuits are required, we believe that air in the venous reservoir should be avoided whenever possible to minimize the risk of neurologic injury.

Cardiovascular and behavioral response to social confrontation: measuring real-life stress in the laboratory

Laboratory investigations of cardiovascular reactivity to mental stress often ignore concomitant differences in cognitive, affective, and behavioral responses that are commonly observed among study participants. To provide a more systematic laboratory methodology to examine relations among cardiovascular, behavioral, and self-report measures of cognitive and affective responses to stress, we developed and tested a social confrontation procedure involving standardized interactions during two scenes. Results of three investigations are presented to illustrate the utility of the social confrontation procedure. In the first two studies, this multidimensional assessment strategy produced results which may foster research projects that bridge separate areas of psychological inquiry. In one application, persons with hypertensive parents, in contrast to persons with normotensive parents, exhibited characteristic negative behavioral responses during both interactions as well as the more commonly-observed exaggerated blood pressure reactions. In the other study, students from less functional families (regarding cohesion and adaptability) were shown to exhibit exaggerated blood pressure reactions in addition to their commonly-reported negative cognitive and behavioral coping styles. Finally, a third study examined how a simple instructional set regarding the expression or suppression of anger influenced participants' responses. Significant differences were observed across response domains, with anger expression resulting in a more intense response than anger suppression. In sum, the social confrontation procedure represents an important methodological development for exploring the relation between response domains, the relation between cardiovascular response to stress and psychosocial risk for cardiovascular disease, and the physiological and behavioral distinction between anger expression and anger suppression.

Calcium dependency of interleukin-1 secretion by a chicken macrophage cell line

The role of calcium in transducing the signal for interleukin-1 (IL-1) secretion was examined in the MQ-NCSU chicken macrophage cell line. Cells were maintained in RPMI 1640 medium supplemented with 5% chicken serum and antibiotic-antimycotic solution at 40 C and 5% CO2. The effects of stimulation with lipopolysaccharide (LPS), calcium ionophore A23187, or a combination of both on IL-1 secretion were examined. Calcium ionophore A23187 did not replace LPS in MQ-NCSU stimulation but the LPS + A23187 combination stimulated more IL-1 than ionophore alone in these cells. The combination of LPS and ionophore did not increase IL-1 secretion above the levels observed with LPS alone. No synergistic effects between LPS and A23187 were evident. In order to demonstrate that IL-1 secretion by the MQ-NCSU cells is a calcium-dependent process, ethylene glycol bis(beta-aminoethyl ether)N,N,N',N'-tetraacetic acid (EGTA) was used to chelate free calcium in the cultures. Incorporation of 5 mM EGTA in the cultures lowered IL-1 stimulated by LPS + A23187 to control levels. Addition of 5 mM CaC12 to EGTA-suppressed cultures restored IL-1 secretion. These results indicate that the calcium ionophore, A23187, augments IL-1 secretion by LPS-stimulated MQ-NCSU macrophages and that IL-1 secretion by these cells is a calcium-dependent process.

B-complex associated immunity to Salmonella enteritidis challenge in congenic chickens

Six trials were conducted during which a total of 12 congenic lines (University of California-Davis, UCD) homozygous for various B-complex haplotypes, were challenged as neonates by intraperitoneal injection with either of two isolates of Salmonella enteritidis. Because these B haplotypes were expressed on a common genetic background (highly inbred Line UCD 003), and mortality differences among lines were statistically significant in three of the six trials, and morbidity (body weight) differences were significant in another trial; it is suggested that B-complex alleles affect the degree of immunity to these isolates. When all lines and trials were compared, line 342 (BC/BC) emerged as particularly resistant, whereas lines 253 (B18/B18) and 254 (B15/B15) were more susceptible. The remainder of the lines were of neutral (intermediate) susceptibility. Sex did not appear to influence the results of the challenge, but more resistance was observed with an increase in the age at inoculation. Although the mechanism that determined this resistance is unknown it was present as early as 3 d of age, and it is suggested that complement proteins, which have a known role in protection from bacterial infections, and are encoded by genes located within the B-complex, or acute phase proteins, may account for these observations. The results provide additional evidence for the importance of the B-complex in determining immunity to Salmonella.

Ropinirole for the treatment of early Parkinson disease: a 12-month experience. Ropinirole Study Group

OBJECTIVE

To evaluate ropinirole hydrochloride as dopaminergic monotherapy in patients with early Parkinson disease.

DESIGN

A 6-month extension of a double-blind, placebo-controlled study.

SETTING

Ambulatory care at 22 different sites in the United States.

PATIENTS

Patients who successfully completed the initial 6-month study could enter the 6-month extension study (ropinirole, n = 70; placebo, n = 77).

INTERVENTION

Use of ropinirole or placebo therapy.

MAIN OUTCOME MEASURES

The efficacy variables were the number of patients who successfully completed the 12-month study and did not require supplemental levodopa, the number of patients requiring supplemental levodopa, and the proportion of patients having an insufficient therapeutic response.

RESULTS

Significantly fewer ropinirole-treated patients met criteria for insufficient therapeutic response (23 [19.8%] of 116) or required the initiation of levodopa therapy (22 [19%] of 116) compared with placebo-treated patients (60 [48%] of 125 patients for insufficient therapeutic response; 57 [45.6%] of 125 patients for additional levodopa). Significantly more ropinirole-treated patients (51 [44.0%] of 116) successfully completed the 12-month study and did not require supplemental levodopa compared with placebo-treated patients (28 [22.4%] of 125). The incidence of adverse experiences and patient withdrawals was low.

CONCLUSION

Ropinirole was effective and well tolerated as monotherapy for 12 months in patients with early Parkinson disease.

Students in compensatory education programs: analysis of scores on performance assessments for the Iowa Test of Basic Skills

Analysis of Mathematics and Language Arts scores for 11,438 fourth- and 8,972 seventh-grade students in compensatory education programs on the performance assessments for the Iowa Test of Basic Skills indicated the students performed poorly, particularly in mathematics.

Abnormal proinsulin levels in thyroid dysfunction measured by a sensitive proinsulin immunochemiluminoassay

Abnormalities of carbohydrate metabolism in hyperthyroid patients have been long noted. Elevated proinsulin level is considered as an early marker of B-cell impairment. Proinsulin levels in hyperthyroid patients decreased after antithyroid drug therapy. However, proinsulin in hypothyroid patients was only rarely reported, and the difference was only demonstrated after glucose stimulation-there was a greater response of proinsulin secretion after thyroxine therapy-and the basal fasting proinsulin level was not different after therapy. One of the reasons might be that the assay was not sensitive enough to detect the change of basal proinsulin levels in patients with hypothyroidism after therapy. A newly developed immunochemiluminometric assay of proinsulin was used to demonstrate that the suppressed proinsulin level increased after thyroxine therapy in hypothyroid patients (4.2 +/- 2.4 vs. 10.0 +/- 5.6 pmol/L, p < 0.05; n = 7). On the other hand, our study also confirmed that the proinsulin levels decreased in hyperthyroid patients after antithyroid therapy by methimazole (27.8 +/- 26.0 vs. 15.8 +/- 15.7 pmol/L, p < 0.05; n = 12). In conclusion, proinsulin increased in hypothyroid patients after thyroxine therapy and decreased in hyperthyroid patients after methimazole therapy. The results demonstrated there is a high correlation between thyroid function and B-cell function in hypothyroid as well as hyperthyroid patients.

The influence of substratum topography on bacterial adhesion to polymethyl methacrylate

The effect of substratum roughness on the adhesion of Pseudomonas aeruginosa and Staphylococcus epidermidis was investigated using PMMA. A small increase in Ra values (0.04-1.24 microm) resulted in a significant increase (P<0.05) in bacterial attachment. Subsequent increases in surface roughness (Ra=1.86-7.89 microm) resulted in a decrease in adhesion, although adhesion was still higher than to the smooth surface. When the PMMA surfaces were coated with protein (bovine serum albumin), no difference (P<0.05) could be determined in the amount of protein adsorbed, irrespective of surface topography. However, the influence of the underlying topography on adhesion was still evident. Substratum topography is an important parameter affecting bacterial adhesion to surfaces.

Modulation of bacterial adhesion to hydrogel contact lenses by albumin

PURPOSE

The purpose of this investigation was to measure the abilities of Pseudomonas aeruginosa and Staphylococcus epidermidis strains to adhere to two hydrogel lens materials and measure the effect of a protein-coated surface on the number of adhered bacteria.

METHODS

Proteins absorbed to contact lenses during sleep were extracted, subjected to sodium dodecylsulphate polyacrylamide gel electrophoresis (SDS-PAGE), and probed for the presence of albumin. Bacterial adhesion was measured by counting bacteria adherent to contact lenses coated in vitro in increasing concentrations of albumin, examining the ability of albumin in solution to prevent adhesion to albumin-coated lenses, and examining the topography of bacterial adhesion by electron microscopy.

RESULTS

Albumin adsorbed to lenses during overnight wear. In vitro studies demonstrated that Polymacon lenses adsorbed more albumin than Etafilcon A lenses. In general, the numbers of adherent bacteria increased with increasing concentration of albumin. Bacteria adhered in higher numbers to Polymacon lenses than Etafilcon A (p < 0.05). P. aeruginosa showed an increased adhesion as the amount of albumin on Etafilcon A lenses increased. There was a decrease in numbers of bacteria adhering per milligram of albumin as the level of albumin increased on Polymacon lenses. Cells tended to adhere to "deposits" on albumin-coated lenses.

DISCUSSION

Albumin adsorbed onto the surface of contact lenses modulated the ability of P. aeruginosa and S. epidermidis to adhere. P. aeruginosa is commonly associated with contact lens-associated microbial keratitis, where bacterial adhesion to contact lenses is believed to be an important first step in the pathogenesis of the disease.

Increased parathyroid hormone-related peptide in patients with hypercalcemia associated with islet cell carcinoma

OBJECTIVE

To report the high prevalence of increased parathyroid hormone-related peptide (PTHrP) in patients with islet cell carcinoma and associated hypercalcemia.

DESIGN

We conducted a retrospective study of PTHrP levels in patients with hypercalcemia and eucalcemia associated with islet cell carcinoma and compared these findings with those in healthy subjects.

MATERIAL AND METHODS

Using a sensitive PTHrP immunochemiluminometric assay, we measured PTHrP levels in 17 patients with islet cell carcinoma and 110 healthy subjects. The differences between PTHrP levels in patients with normal and those with high serum calcium concentrations were analyzed statistically.

RESULTS

PTHrP levels were significantly higher (P < 0.01) in 10 patients with hypercalcemia and islet cell carcinoma (median, 14.0 pmol/L; range, undetectable to 40.1) than in 7 patients with eucalcemia and islet cell carcinoma (median, undetectable; range, undetectable to 1.3 pmol/L) or in the 110 healthy subjects (median, undetectable; range, undetectable to 4.2 pmol/L). The range of increased PTHrP levels in hypercalcemic islet cell carcinoma was 2 to 20 times the upper normal limit (2.0 pmol/L). Decreased PTHrP and serum calcium and increased parathyroid hormone levels were demonstrated in two patients after effective therapy. For all seven eucalcemic patients with islet cell carcinoma, PTHrP levels did not differ significantly from those in healthy subjects.

CONCLUSION

PTHrP levels are increased in a substantial proportion of patients with hypercalcemia and islet cell carcinoma and seem to decrease after treatment of the underlying tumor. Measurement of PTHrP levels may be useful for confirming the diagnosis of hypercalcemia associated with malignant disease and for monitoring of therapy.

Parathyroid-hormone-related peptide immunochemiluminometric assay. Developed with polyclonal antisera produced from a single animal

An immunochemiluminometric assay of parathyroid-hormone-related peptide (PTHrP) was developed with purified antisera produced from a single goat immunized with (1-86) PTHrP. One batch of purified antibodies was labeled with acridinium ester used as tracer antibodies; a second batch of the purified antibodies was immobilized onto plastic bead. Sensitivity of the assay was 0.1 pmol/L. The assay had no cross-reactivity with PTH. Seventy-five percent of healthy individuals had undetectable PTHrP (mean +/- S.D. were 0.73 pmol/L +/- 0.6; n = 110). The 95 percent upper reference limit was 2.0 pmol/L. Five of the seven patients with humoral hypercalcemia associated with malignancy (HHM) of solid-tumor had PTHrP greater than 2.0 pmol/L. The test efficacy in detecting HHM was 71 percent, which is similar to previous extraction radioimmunoassay (RIA) or immunoradiometric assay (IRMA). The new assay lowered the detection limit to 0.1 pmol/L, which is a great improvement from that of RIA at 2.0 pmol/L and IRMA at 1.0 pmol/L; however; it did-not improve the test efficacy in detecting patients with HHM. It may indicate the patients with HHM only have elevated plasma PTHrP in 70 percent of them. Technically, the method can be used as a model to develop chemiluminescent esoteric test for research or reference laboratories.

Ropinirole for the treatment of early Parkinson's disease. The Ropinirole Study Group

A prospective, randomized, placebo-controlled, double-blind, parallel-group, 6-month study assessed the efficacy and safety of ropinirole, a nonergoline D2-dopamine agonist, in patients with early Parkinson's disease (n = 241; Hoehn & Yahr stages I to III) with limited or no prior dopaminergic therapy. Patients (mean age, 62.8 years), stratified by concomitant use of selegiline, were randomized to ropinirole (n = 116) or placebo (n = 125). The starting dose of ropinirole was 0.25 mg tid with titration to at least 1.5 mg tid (maximum dose, 8 mg tid). Primary efficacy endpoint was the percentage improvement in Unified Parkinson's Disease Rating Scale (UPDRS) motor score. Ropinirole-treated patients had a significantly greater percentage improvement in UPDRS motor score than patients who received placebo (+24% vs -3%; p < 0.001). Ropinirole was well tolerated and patient withdrawals were infrequent. Most adverse experiences were related to peripheral dopaminergic activity. Ropinirole monotherapy is an effective and well-tolerated therapeutic option for treatment of early Parkinson's disease.

Resistance, susceptibility, and immunity to Eimeria tenella in major histocompatibility (B) complex congenic lines

The major histocompatibility (B) complex influence on resistance, susceptibility, and immunity to Eimeria tenella was examined in UCD B complex congenic chicken lines. In Experiment 1, 6-wk-old chicks from 12 UCD congenic lines were weighed and assigned to either challenge or control groups. The challenge group received a dose of 10,000 E. tenella oocysts. Response to challenge was evaluated by body weight gain and cecal lesion scores. Cecal lesion scores in B3B3 chickens were significantly lower than those of all other genotypes. Genotype B2B2 had the highest lesion scores, which were significantly different from the lesion scores calculated for B3B3, B18B18, and B21B21 chickens but were not significantly different from B14B14, B15B15, B17B17, B19B19, B24B24, BCBC, BJBJ, and BQBQ genotypes. The B21B21 chickens had significantly lower lesion scores than B2B2, B14B14, and BCBC chickens. No other significant lesion score differences were found among the remaining lines. The highest weight gain found in B19B19 chickens was significantly different from that of B3B3, B14B14, B15B15, B17B17, B18B18, B24B24, and BCBC chickens. The B15B15 chickens had the lowest weight gain, which was significantly different from that of B2B2, B19B19, B21B21, B24B24, BJBJ, and BQBQ chickens. Experiment 2 tested the immune response to E. tenella after low dose oocyst immunization. Chicks from 10 UCD 003 congenic lines were divided into three groups: control, challenge, and immune. At 5 wk of age, the immune group was immunized with 500 E. tenella oocysts for 5 consecutive d. Fourteen days after the last immunization all chicks were weighed, and 10,000 E. tenella oocysts were administered to the challenge and immune groups. Significant lesion score differences existed among all three treatments: control (0), immune (2.14 +/- 0.1); challenge (3.13 +/- 0.1). Among immune birds, B3B3 and BQBQ chickens had significantly lower lesion scores than B19B19, B24B24, B14B14, and B2B2 chickens. Neither B19B19 nor B24B24 chickens were well-protected, as indicated by their higher lesion scores. No significant differences in weight gain were found in immune birds. The B complex affected resistance and susceptibility as well as the immune response to E. tenella. Cecal lesion scores following challenge in naive birds or after immunization were influenced by the B complex, whereas weight gain was affected in naive birds only. These effects may be manifested through differences in immune competence at the time of challenge or immunization, the amount of parasite antigen production, or the threshold doses for effective immunization.

Characterization of immune response to Eimeria tenella antigens in a natural immunity model with hosts which differ serologically at the B locus of the major histocompatibility complex

A model to simulate natural immunity to Eimeria tenella was developed in three chicken lines which differ at the B locus of the major histocompatibility complex. Homozygous, 1-day-old chicks of the B19B19, B24B24, or B30B30 genotype were trickle immunized by being orally fed a small infectious dose of E. tenella oocysts for 5 consecutive days. These naturally exposed birds were then challenged at different times between 5 and 24 days after the final dose, and the level of protection was assessed 6 days after challenge, using body weight gain and intestinal lesion scores. The duration of immunity in naturally exposed birds differed among the major histocompatibility complex lines. Trickle immunization of the B19B19 haplotype afforded the longest and strongest level of protection compared to the other two haplotypes tested. In addition, in vitro splenic and peripheral blood lymphocyte proliferative responses in trickle-immunized birds were measured against sporozoite, merozoite, and tissue culture-derived E. tenella parasite antigens isolated from the recently described SB-CEV-1/F7 established cell line. The lymphocytes obtained from B19B19 birds trickle immunized responded in vitro to the E. tenella-infected SB-CEV-1/F7 tissue culture-derived parasite antigen. Furthermore, antigen-specific immune responses appeared earlier in immune, challenged B19B19 birds than in their naive, challenged counterparts. The development of a model simulating natural immunization will serve as a foundation to further characterize both humoral and cell-mediated responses to E. tenella tissue culture-derived parasite antigens and to better understand host protective immune responses to avian coccidiosis.

Governance of integrated delivery systems/networks: a stakeholder approach

The health care environment is complex and turbulent, and traditional governance forms face many challenges. As integrated delivery systems/networks are formed, governance structures must be responsive to both internal and external stakeholders. Both internal efficiencies and socially responsible actions are required of these relatively new organizational forms. To meet these needs, a two-tier governance structure is presented that consists of overarching and facilitating boards.

Sequence variation in the src gene product affects metastasis formation: the central, but not exclusive, role of the tumor immune response

Sequence variation in the src gene product could, in principle, influence metastasis formation through either of 2 effects: an alteration in tumor antigenicity or a non-immune-mediated change in one or more src-associated functions. Our present results establish that both mechanisms underlie the difference in relative levels of metastasis formation induced by the v-src vs. the c-src(527) oncogene. A point that emerges from this analysis is the segregation, within a chicken line genotypically uniform at the major histocompatibility (B) complex (MHC), of a phenotype defined by strong resistance to secondary v-src-induced tumor challenge. The pattern of segregation is consonant with the possibility that a gene unlinked to the MHC governs immune response levels to v-src-encoded tumor antigen.

Eliminating inappropriate classroom behavior using a DRO schedule: a preliminary study

The purpose of this study was to eliminate out-of-seat behavior of a 14-yr.-old boy with learning disabilities using a single-subject design. Based on functional analysis, a Differential Reinforcement of Other Behavior interval schedule was used to eliminate an inappropriate behavior. During baseline, an average of 15 out-of-seat behavior problems were recorded. After 4 wk. of intervention, the inappropriate out-of-seat behavior was eliminated and on-task behavior improved.

Assignment of Rfp-Y to the chicken major histocompatibility complex/NOR microchromosome and evidence for high-frequency recombination associated with the nucleolar organizer region

Rfp-Y is a second region in the genome of the chicken containing major histocompatibility complex (MHC) class I and II genes. Haplotypes of Rfp-Y assort independently from haplotypes of the B system, a region known to function as a MHC and to be located on chromosome 16 (a microchromosome) with the single nucleolar organizer region (NOR) in the chicken genome. Linkage mapping with reference populations failed to reveal the location of Rfp-Y, leaving Rfp-Y unlinked in a map containing >400 markers. A possible location of Rfp-Y became apparent in studies of chickens trisomic for chromosome 16 when it was noted that the intensity of restriction fragments associated with Rfp-Y increased with increasing copy number of chromosome 16. Further evidence that Rfp-Y might be located on chromosome 16 was obtained when individuals trisomic for chromosome 16 were found to transmit three Rfp-Y haplotypes. Finally, mapping of cosmid cluster III of the molecular map of chicken MHC genes (containing a MHC class II gene and two rRNA genes) to Rfp-Y validated the assignment of Rfp-Y to the MHC/NOR microchromosome. A genetic map can now be drawn for a portion of chicken chromosome 16 with Rfp-Y, encompassing two MHC class I and three MHC class II genes, separated from the B system by a region containing the NOR and exhibiting highly frequent recombination.

Antibody response to sheep red blood cells in major histocompatibility (B) complex aneuploid line of chickens

An integral part of the immune response is the production of antibodies specific for different antigenic challenges. Genes of the MHC encode products that regulate immunity. This study utilized the FCT-15 line of chickens, which is aneuploid for the chromosome containing the ribosomal RNA genes (rDNA) and the MHC or B complex to determine whether an antibody response to SRBC would vary as a function of B complex gene dose. Mating of trisomic parents (B15B15B15) animals produced progeny having either a disomic (B15B15), trisomic (B15B15B15), or tetrasomic (B15B15B15B15) B complex dosage. The number of B/rDNA chromosomes, and thus the B complex dosage was determined by feather pulp nucleolar typing of chicks at hatch. A 5% SRBC antigenic challenge, which induces a T cell-dependent antibody response, was injected at 6 wk of age. Samples taken prior to SRBC injection as well as 5, 8, and 12 d postinjection were assayed for total and mercaptoethanol-resistant antibody. Peak antibody titers (log2), day of peak titer and rate of titer decline were calculated using a quadratic equation for each bird. Differences among the three B complex dosages were evaluated by analysis of variance. Antibody titers rose from 5 to 8 d postinjection and declined thereafter without significant differences among the three B complex doses. Calculations from the quadratic equations showed that B complex dose affected neither peak antibody titer nor day of peak titer. However, trisomic and tetrasomic animals had significantly more rapid rates of decline from the maximum titer. In aneuploid chickens, changes in antigen processing, antigen presentation, or persistence of processed antigen may maintain levels of antibody production found in disomic chickens and explain the more rapid decline of titer.

Differential antibody responses in 6.B major histocompatibility (B) complex congenic chickens

Lines 6.6-2 (B2B2) and 6.15-5 (B2B2), congenic for the major histocompatibility (B) complex with > 99.9% background gene uniformity, were used to examine primary antibody responses to two antigens. In each of two trials, 1 mL of 5% SRBC, a T cell-dependent antigen, or 0.1 mL of Brucella abortus (BA), a T cell-independent antigen, was injected into separate groups of each B genotype aged 3 and 6 wk. Blood samples were taken from the chickens 7 d after immunization. Serum titers (log2) for both total antibody and mercaptoethanol (ME)-sensitive antibody to detect IgG were assayed by microtiter procedures. Least squares analysis of variance and Fisher's protected Least Significant Difference at P < 0.05 were used to evaluate the data. The total anti-SRBC antibody titer was significantly higher in B5B5 chicks than in B2B2 chicks at 4 and 7 wk of age. There was no significant difference in ME sensitive antibody to SRBC. Chicks of the B5B5 genotype also had significantly higher total and IgG antibody titers to BA at both ages than B2B2 chicks. The results indicate that 4- and 7-wk-old B5B5 chicks had a significantly stronger antibody response to SRBC or BA than B2B2 chicks.

Endogenous c-src as a determinant of the tumorigenicity of src oncogenes

We have compared the tumorigenicity of two src oncogenes, v-src and c-src(527), whose respective protein products pp60v-src and pp60c-src(527) show a different spectrum of amino acid substitutions vis-à-vis the c-src protooncogene-encoded product pp60c-src. Whereas the extent of primary tumor growth induced by c-src(527) was quite similar in the two chicken lines tested, the extent of v-src-induced tumor growth showed a marked line dependence. As examined with a line of chickens that shows immune-mediated regression of v-src-induced tumors, a weaker tumor immunity, as correlated with a greater level of primary tumor growth, resulted from inoculation of c-src(527) DNA than of v-src DNA. These observations indicated that the v-src-specific amino acid substitutions define a major tumor antigenicity. That a separate src-associated antigenicity is also targetable by the tumor immune response followed from the finding that the level of protective immunity against the growth of c-src(527) DNA-induced tumors was augmented under conditions of the prior regression of v-src DNA-induced tumors. As this latter antigenicity may include one or more c-src(527)-encoded peptides that are equivalent to c-src-encoded self peptides, these observations suggest that a host tolerance to pp60c-src can be broken so as to permit a tumor immune response based on recognition of self peptides of pp60c-src(527).

Avian hematopoiesis in response to avian cytokines

The objective of this study was to examine the hematopoietic cell proliferation and differentiation potential of growth factors produced by chicken macrophages. Bone marrow (BM) cells (25 x 10(3)) from newly hatched B15B15 K-strain Leghorn chicks were seeded in .5 mL serum-free semi-solid culture supplemented with 10% (vol/vol) of a conditioned medium (CM) from a chicken macrophage cell line, MQ-NCSU. The conditioned medium was obtained by culturing MQ-NCSU cells either in LM-HAHN (CMI) or RPMI-1640 (CMII) growth medium. The control cultures contained only LM-HAHN or RPMI medium. Bone marrow cells in the presence of CMI differentiated predominately into granulocyte colonies (Experiment 1 = 84 +/- 9.2; Experiment 2 = 105 +/- 5). No colonies were observed in the control cultures. Stimulation of MQ-NCSU cells with lipopolysaccharide (LPS) produced a CM that differentiated BM cells predominantly into macrophage colonies (122 +/- 16.3 in CMI and 92 +/- 5.6 in CMII). These data suggest that MQ-NCSU cells spontaneously secrete a factor with the potential to promote granulocyte differentiation. However, upon stimulation with LPS, the factor secreted had macrophage colony stimulation potential (M-CSF), which was similar in activity when compared with the activity of recombinant chicken myelomonocytic growth factor (r-cMGF). Another CM from chicken fibroblasts (FCM) was tested on BM cells from K-strain Leghorns and Arbor Acres x Arbor Acres broiler chicks. Data from three experiments showed that 25 x 10(3) BM cells from K-strain chicken yielded more macrophage and granulocytes colonies (82 +/- 14) than those from broilers (56 +/- 12). This study suggests that avian cytokines exhibit progenitor cell differentiation potential and that this activity is dependent upon the source of cytokines and their targets.

Proinsulin level in diabetes mellitus measured by a new immunochemiluminometric assay

Proinsulin, the precursor of insulin and C-peptide, is detectable in the circulation and is a potential marker of beta-cell dysfunction. Currently, circulating proinsulin can be measured accurately without the interference of insulin or C-peptide by immunometric assays and a few specific radioimmunoassays. An immunochemiluminometric assay was developed in our laboratory by using two immunopurified polyclonal antibodies of C-peptide and insulin from two goats. The C-peptide antiserum was labeled with acridinium ester. The insulin antiserum was immobilized onto a plastic bead. With this assay, proinsulin levels found in noninsulin-treated patients with noninsulin-dependent diabetes mellitus (63 +/- 58 pmol/L; n = 19) were significantly higher (p < 0.05) than levels in insulin-treated patients with noninsulin-dependent diabetes mellitus (30 +/- 24 pmol/L; n = 43), and both were significantly higher (p < 0.001) than proinsulin levels in patients with insulin-dependent diabetes mellitus. In addition, there was a negative correlation between proinsulin levels and duration of years on insulin therapy in patients with noninsulin-dependent diabetes mellitus (r = -0.4795; p < 0.01).

Identification of Salmonella enteritidis from experimentally infected hens using a colorimetric DNA hybridization method

Identification of Salmonella enteritidis from cloacally challenged commercial laying hens was studied by comparing bacterial isolations using conventional methods with detection by the use of the GENE-TRAK colorimetric DNA probe assay. More positive test results were obtained using the latter on days 14, 28, and 42 postchallenge, but the difference between the two methods was not statistically significant. Over the duration of the experiment, positive cloacal samples were statistically more frequent from a commercial strain of white leghorn hens when compared with a commercial brown egg-producing strain (28/60 vs. 9/57; chi-square 1 df = 12.9, P < 0.001). Eggs having various shell defects were produced by the infected hens only after Salmonella challenge. These defects included, in order of frequency, elongated shape, thin shells, off-white color (tints), small size, wrinkles, and pimples. No Salmonella could be recovered from 193 defective eggs, nor were positive isolates made from additional tests performed on 50 normal eggs. Proteus sp. was isolated from 10 eggs, however. Our observations demonstrate that the GENE-TRAK colorimetric method is comparable with conventional bacteriology for the identification of Salmonella in cloacal samples taken from laying hens. Moreover, the two methods demonstrate the existence of breed differences in susceptibility to S. enteritidis challenge.

Major histocompatibility (B) complex control of the formation of v-src-induced metastases

Previous observations have shown that the major histocompatibility (B) complex is a determinant of the growth of v-src-induced primary tumors. In the present study, we have observed with two chicken lines congenic for B complex alleles that the control of v-src-mediated oncogenesis by the B complex extends to metastasis formation. In addition, our results show that the differences in metastasis frequencies between these two lines are correlated with the relative strengths of their respective tumor immune responses.

Catecholamines modulate chicken immunoglobulin M and immunoglobulin G plaque-forming cells

Norepinephrine (NE) and epinephrine (E) function as chemical messengers in the central nervous and the endocrine systems of the chicken. The effects of in vivo and in vitro exposure of NE and E on IgM and IgG splenic plaque-forming cell (pfc) formation were determined to the antigen SRBC. Six-week-old Line UNH 105 New Hampshire chickens were injected i.v. with NE (500 micrograms/kg BW) or E (100 micrograms/kg BW) followed by 1 mL of 5% SRBC 30 min later. Five days after antigen injection, IgM and IgG pfc were assayed. Compared with controls, in vivo NE suppressed (P < .05) IgM and IgG pfc formation. In vitro NE treatment of splenic lymphocytes reduced (P < .05) IgM pfc but did not affect IgG pfc numbers. In vivo treatment with E increased (P < .05) IgM pfc whereas in vitro E exposure increased (P < .05) IgM pfc. Immunoglobulin G pfc were suppressed (P < .05) by both in vivo and in vitro E exposure. The presence of surface receptors for NE and E on splenic lymphocytes was determined using in vitro incubation with antagonists to alpha and beta receptors. These data suggest that there are alpha and beta receptor sites on lymphocytes for NE and E, and that these catecholamines have a regulatory role in plaque cell proliferation.

Continuous administration of dopamine alters cellular immunity in chickens

Dopamine administered continuously through osmotic pumps altered the PHA wattle response and in vitro leukocyte capillary tube migration in UNH 105 chickens. The PHA wattle response was suppressed significantly by 48 hr exposure to dopamine at a dose of 1 microgram/hr. Administration of 10 micrograms/hr dopamine for 48 hr enhanced significantly in vitro leukocyte migration.

Correlates of interventions with self-injurious behaviour

A review was conducted of published intervention research on the self-injurious behaviour (SIB) of individuals with severe or profound mental retardation. The review comprised articles published between 1980 and 1990. Thirty-eight biodemographic and environmental variables were investigated, with type of SIB and intervention type considered primary variable classes. Efficacy was also investigated as an additional variable. Cross-tabulations were performed on selected variables with 24 significant and five marginally significant results obtained. These results indicated that there were possible biases in treatment approaches, problems in compliance with standards of practice, and differential efficacy levels related to certain variable types. Findings were discussed in relation to establishing a prototype for successful SIB interventions.

Response of six major histocompatibility (B) complex recombinant haplotypes to Rous sarcomas

Six B complex recombinants, BR1 (F24-G23), BR2 (F2-G23), BR3 (F2-G23), BR4 (F2-G23), BR5 (F21-G19), and BR6 (F21-G23), from the fourth backcross generation to highly inbred line UCD 003 (B17B17) were studied for their response to Rous sarcomas. Eight hatches were produced from heterozygous (BRnB17) parents. Chicks were wingweb inoculated with 50 pock-forming units of Rous sarcoma virus (RSV) at 6 wk of age. A tumor profile index (TPI), based on degree of tumor regression, was evaluated by analysis of variance. BR2, BR3, and BR4 are serologically similar F2-G23 recombinants. Haplotype B2, the origin of BF2, is a known tumor regressor, yet BR2BR2 chickens had a significantly lower TPI than BR3BR3 and BR4BR4 chickens. The TPI of BR2BR2 (F2-G23) chickens was also significantly lower than the TPI of chickens homozygous for BR1 (F24-G23) and BR5 (F21-G19). The BR6BR6 (F21-G23) chickens had significantly lower TPI than all homozygotes except BR2BR2 (F2-G23). Among heterozygous genotypes, BR2B17, BR5B17, and BR6B17 differed significantly from BR1B17, BR3B17, and BR4B17. These results suggest that serologically similar recombinants that contain (F2-G23) possess different genes affecting tumor regression. In addition, degrees of tumor regression in BR5 (F21-G19) and BR6 (F21-G23), both of which contain BF21, may be due to genetic differences within the B-F/B-L or B-G regions.

Intraoperative monitoring of parathyroid procedures by a 15-minute parathyroid hormone immunochemiluminometric assay

OBJECTIVE

To report the recent development and validation of a sensitive 15-minute immunochemiluminometric assay (ICMA) of parathyroid hormone (PTH).

DESIGN

The characteristics and applications of a new "rapid" PTH ICMA are described, and the advantages in comparison with other assays are discussed.

MATERIAL AND METHODS

The 15-minute PTH ICMA was achieved by using a higher incubation temperature (45 degrees C rather than room temperature) and a concentration of tracer antibodies that was 5 times that in the regular 18-hour assay. The sensitivity, recovery, and linearity of dilution of the rapid ICMA were assessed, as was its ability to reflect intraoperative changes in PTH concentration after parathyroidectomy in patients with hyperparathyroidism.

RESULTS

The sensitivity of the ICMA was 0.3 pmol/L in comparison with 0.08 pmol/L for the regular 18-hour assay (normal range, 1.0 to 5.0). The recovery of added PTH was 84% by using ethylene-diaminetetraacetic acid-plasma as the specimen. Moreover, the linearity of specimens after dilution was good. The assay demonstrated a rapid response to parathyroid gland removal. In most patients, PTH levels declined precipitously (to less than 30% of basal values) within 5 minutes after parathyroid resection. PTH levels remained low to undetectable at 10 and 20 minutes after excision.

CONCLUSION

This rapid PTH ICMA may be of assistance to endocrine surgeons in the monitoring of PTH function after both parathyroid and thyroid surgical procedures.

Proinsulin by immunochemiluminometric assay for the diagnosis of insulinoma

We used a newly developed immunochemiluminometric assay of proinsulin to determine its relative utility vis-à-vis C-peptide and insulin for the diagnosis of insulinoma. The evaluation was conducted in 20 consecutive patients with histologically confirmed insulinoma and 22 normal subjects who underwent a prolonged fast according to a standard protocol. Patients with insulinoma fasted to the point of demonstrating Whipple's triad; normal subjects fasted to 72 h. At the end of the prolonged fast, when the glucose value was 2.8 mmol/L or less (50 mg/dL), all three hormones had equal sensitivity (100%) in detecting insulinoma with no overlap with the values of normal subjects. When glucose levels were between 2.8 mmol/L (50 mg/dL) and 3.3 mmol/L (60 mg/dL) at the end of the prolonged fast, proinsulin was better than C-peptide and insulin in the diagnosis of insulinoma. The sensitivity was 90% for proinsulin and 85% for both C-peptide and insulin. Therefore, proinsulin not only is useful for the diagnosis of insulinoma, but it may have greater diagnostic accuracy than C-peptide and insulin.

Resistance to Marek's disease in chickens with recombinant haplotypes to the major histocompatibility (B) complex

Genetic resistance to Marek's disease (MD) is associated with the B-F region of the MHC. The resistance of chickens possessing either of two MHC haplotypes to challenge with different strains of MDV was examined. Chickens with serologically similar MHC recombinants BR2 and BR4 (both BF2-G23) were backcrossed for four generations to the highly inbred UCD-003 line (B17B17). Heterozygotes (B17BF2-G23) were mated to produce BR2BR2 and BR4BR4 homozygotes with 93% background gene uniformity. Both genotypes were highly resistant to GA-5 MDV, having an incidence of 0 and 8% MD for BR2BR2 and BR4BR4, respectively, whereas the incidence of MD in the UCD-003 birds was above 80%. Challenge with the very virulent RB-1B strain caused 10% and 31% MD in the BR2BR2 and BR4BR4 chickens, respectively, compared with 100% and 52% in the B17B17 (UCD-003) and B23B23 (New Hampshire 105) lines, respectively. Viremia levels at 5 and 6 d postinfection were significantly lower in BR2BR2 and B23B23 than in B17B17 genotypes.

Analysis of macrophage functions in Rous sarcoma-induced tumor regressor and progressor 6.B congenic chickens

Macrophage functional competence was studied in two congenic chicken lines 6.6-2 (B2B2) and 6.15-5 (B5B5) which are regressors and progressors, respectively, of Rous sarcoma-induced tumors. Sephadex-elicited abdominal exudate cells (AEC) were harvested from 4-week-old chickens to determine their total number, glass adherence potential, percentage of adherent macrophages and phagocytosis of antibody coated (ops) and uncoated (unops) sheep red blood cells (SRBC). Tumoricidal abilities of culture medium conditioned with lipopolysaccharide treated macrophages and of macrophages cocultured with target cells were assessed against 51Cr-labelled tumor cell targets. The congenic lines did not differ in total AEC or percent macrophages. However, AEC from B5B5 birds exhibited significantly lower (P < 0.05) glass-adherence potential than AEC from B2B2 birds exhibited significantly lower (P < 0.05) glass-adherence potential than AEC from B2B2 birds. The percentage of phagocytic macrophages did not differ between lines for unop-SRBC, whereas a higher percentage of B5B5 compared with B2B2 birds (P < 0.05) macrophages phagocytized ops-SRBC. Macrophages from B5B5 birds had significantly (P < 0.05) lower activity in both tumoricidal tests. These results imply that the tumor progression in B5B5 birds is associated with reduced activation of macrophages towards a tumoricidal pathway.

Biogenic amines regulate avian immunity

Alzet mini-osmotic pumps were implanted subcutaneously to administer norepinephrine (NE) and epinephrine (E) to 6-wk-old line UNH 105 chickens. Dose-time studies showed the most effective NE and E dose and exposure time on two chicken cellular immune responses: the phytohemagglutinin (PHA) wattle response and leukocyte migration. Administration of 1 microgram/h NE for 72 h suppressed significantly the wattle stimulation index [2.48 +/- .3 (SE)] compared to that of saline controls (4.1 +/- .3) but enhanced mean leukocyte migration (7.7 +/- .3 versus 4.9 +/- .3). Epinephrine at 1 microgram/h for 72 h significantly suppressed the wattle index (1.8 +/- .2) compared to that of controls (2.8 +/- .3) but E at 1 microgram/h for 48 h enhanced leukocyte migration (9.5 +/- .2 versus 6.4 +/- .2). Continuous administration of NE and E at physiological levels alters cell-mediated immunity and appears to have an immune regulatory role in the chicken.

The effects of prolonged weightlessness and reduced gravity environments on human survival

The manned exploration of the solar system and the surfaces of some of the smaller planets and larger satellites requires that we are able to keep the adverse human physiological response to long term exposure to near zero and greatly reduced gravity environments within acceptable limits consistent with metabolic function. This paper examines the physiological changes associated with microgravity conditions with particular reference to the weightless demineralizatoin of bone (WDB). It is suggested that many of these changes are the result of physical/mechanical processes and are not primarily a medical problem. There are thus two immediately obvious and workable, if relatively costly, solutions to the problem of weightlessness. The provision of a near 1 g field during prolonged space flights, and/or the development of rapid transit spacecraft capable of significant acceleration and short flight times. Although these developments could remove or greatly ameliorate the effects of weightlessness during long-distance space flights there remains a problem relating to the long term colonization of the surfaces of Mars, the Moon, and other small solar system bodies. It is not yet known whether or not there is a critical threshold value of 'g' below which viable human physiological function cannot be sustained. If such a threshold exists permanent colonization may only be possible if the threshold value of 'g' is less than that at the surface of the planet on which we wish to settle.

Comparative development of Eimeria tenella in primary chick kidney cell cultures derived from coccidia-resistant and -susceptible chickens

A sixfold difference in resistance to coccidia (Eimeria tenella) infection between a resistant and a susceptible line of Auburn White Leghorn chickens, derived by selective breeding, has been reported. The purpose of the following study was to determine whether the resistance or susceptibility phenomenon in the Auburn lines could be manifested in a homogeneous group of isolated host kidney cells that support E. tenella development in vitro but not normally in vivo. Propagation of the parasite in host cells in vitro eliminates humoral and cellular elements of immunity, and allows the study of host genetic influences at the cellular level. Differences in parasite development were examined between the two lines of cells in vitro after 48 and 96 h of incubation; time periods that reflect initial infection of the host cells by the parasite and the subsequent asexual development. Quantification of differences by liquid scintillation counting was based on parasite-specific incorporation of pyrimidines, specifically [3H]-uracil. The results supported previous findings that overall E. tenella development was significantly greater in the host cells from the susceptible line than in the cells from the resistant cultures at both time periods.

Major histocompatibility (B) complex control of the growth pattern of v-src DNA-induced primary tumors

Observations that the major histocompatibility (B) complex is a determinant of the growth pattern of Rous sarcoma virus (RSV)-induced tumors raised the question as to whether control is exerted at the level of a v-src-determined, i.e., transformation-specific, function. To investigate this point, the tumor size scores and tumor profile indices of v-src-induced tumors were compared in two lines of chickens congenic for B complex genotypes. The finding that the growth patterns of tumors, induced by v-src DNA inoculation at 6 weeks posthatch, differ in these two lines establishes that the B complex exerts control over tumor growth at the level of a v-src-determined function. The potential importance of this control, in terms of the naturally occurring case of an avian sarcoma virus infection, is suggested by the observation that the patterns of tumor growth in a given congenic line are similar whether the tumors are induced by v-src DNA or by RSV.

Differential resistance to Staphylococcus aureus challenge in major histocompatibility (B) complex congenic lines

Ten inbred B-congenic Leghorn lines were challenged with two isolates of Staphylococcus aureus at 3 days and 6 wk of age. Significant differences in mortality were observed among such lines when challenged at 3 days with either S. aureus Isolate P4L (moderately pathogenic) or S. aureus Isolate 3727 (highly pathogenic). Line 331 (B2/B2 genotype) had lower mortality than either Line 004 (B17/B17, chi 2 = 4.13, P < .05) or Line 253 (B18/B18, chi 2 = 4.23, P < .05) challenged with Isolate P4L. The use of a susceptibility index allowed for the detection of additional differences among the various lines challenged by Isolate 3727. Line 336 (BQ/BQ) was more resistant than either Line 335 (B19/B19, P < .01) or Line 330 (B21/B21, P < .01). No significant differences were found among the lines challenged at 6 wk by either isolate. The results provide additional evidence for the importance of the B complex in genetically determined disease resistance, and further demonstrate the usefulness of congenic lines in such investigations.

C-peptide immunochemiluminometric assay developed from two seemingly identical polyclonal antisera

Two goats were immunized with synthetic C-peptide. Their antisera were immunopurified separately on a C-peptide affinity column. The purified antibodies from one goat were labeled with acridinium ester; the other goat's antibodies were immobilized on plastic beads. Standards were synthetic C-peptide. The new immunochemiluminometric assay (ICMA) for C-peptide was compared with our routine radioimmunoassay (RIA) by using Novo's 125I-labeled C-peptide and Cambridge Medical's antiserum. Good correlations were found between the new ICMA and the RIA (r = 0.951; ICMA = 1.07 RIA + 147; n = 112). The new ICMA showed good recoveries (91 percent to 108 percent) of added C-peptide and parallelism of diluted specimens. The incubation time was shortened from 48 hours for RIA to five hours for ICMA. In addition, it was shown that polyclonal antisera from two animals immunized by the same antigen and purified by the same affinity column can be used to prepare immunometric assays.