Normal human sera contain antibodies directed at Fab of IgA

Serum samples from 26 normal volunteers were evaluated by isotype-specific ELISA for the presence of IgG and IgM antibodies directed at IgA. Although there were wide variations in antibody levels, anti-IgA antibodies of both isotypes were found in all individuals tested. The anti-IgA activity was detected against a variety of polymeric and monomeric IgA1 and IgA2 myeloma proteins containing both kappa and lambda light chains. By using Fab and Fc fragments generated by incubation of an IgA1 myeloma protein with IgA1 protease, it was shown that the anti-IgA activity was specific for the Fab portion of the IgA molecule. It was also demonstrated that the serum of two individuals contained both IgG and IgM activity directed at autologous affinity-purified IgA. IgM antibody levels against both whole IgA and Fab of IgA were significantly higher than IgG antibody levels. Cells producing anti-IgA antibodies of both isotypes were detected in lipopolysaccharide-stimulated human spleen.

Normal human sera contain antibodies directed at Fab of IgA

Serum samples from 26 normal volunteers were evaluated by isotype-specific ELISA for the presence of IgG and IgM antibodies directed at IgA. Although there were wide variations in antibody levels, anti-IgA antibodies of both isotypes were found in all individuals tested. The anti-IgA activity was detected against a variety of polymeric and monomeric IgA1 and IgA2 myeloma proteins containing both kappa and lambda light chains. By using Fab and Fc fragments generated by incubation of an IgA1 myeloma protein with IgA1 protease, it was shown that the anti-IgA activity was specific for the Fab portion of the IgA molecule. It was also demonstrated that the serum of two individuals contained both IgG and IgM activity directed at autologous affinity-purified IgA. IgM antibody levels against both whole IgA and Fab of IgA were significantly higher than IgG antibody levels. Cells producing anti-IgA antibodies of both isotypes were detected in lipopolysaccharide-stimulated human spleen.

IgA antibody-producing cells in peripheral blood after antigen ingestion: evidence for a common mucosal immune system in humans

The finding that ingestion of antigens results in the selection induction of IgA antibodies in external secretions suggests that antigen sensitizes Peyer's patch lymphoid cells, which migrate to mucosal sites and generate local secretory IgA (S-IgA) antibody responses. Evidence for a common mucosal immune system in humans has been scanty because of the difficulty in demonstrating migratory behavior of Peyer's patch cells. In the present study, peripheral blood mononuclear cells (PBMC) from human volunteers who had ingested capsules containing killed Streptococcus mutans were assayed for spontaneous antibody-producing cells. Four of five volunteers exhibited circulating IgA-producing cells within 7 days and reached maximum responses by days 10-12. One IgA-deficient subject exhibited IgM responses with identical kinetics. Pokeweed-mitogen-stimulated PBMC produced anti-S. mutans antibodies predominantly of the IgA isotype. Significant S-IgA anti-S. mutans antibodies were detected in saliva and tears by day 14, and the antibodies reached maximum titers by 3 weeks. No changes in serum anti-S. mutans antibodies were noted. The IgA-deficient subject produced salivary secretory IgM antibodies. These results suggest that, after antigen ingestion, peripheral blood contains antigen-specific precursors of IgA plasma cells and that their presence precedes the appearance of S-IgA antibodies in external secretions. Therefore, these experiments provide further support for the existence of a common mucosal immune system in humans.

VHDJH formation and DJH replacement during pre-B differentiation: non-random usage of gene segments

The Abelson murine leukemia virus (A-MuLV) transformed cell line 300-19 was derived from the bone marrow of an adult NIH/Swiss outbred mouse. The original 300-19 clonal isolate carried DHH rearrangements of both JH alleles, a molecular genotype characteristic of early pre-B cells. During propagation in culture, the 300-19 line frequently generates secondary rearrangements of its JH alleles including rearrangements which append VH segments to the pre-existing DJH complexes to form complete VHDJH variable region genes and secondary D to JH rearrangements which replace the pre-existing DJH rearrangement by joining an upstream D to a downstream JH. The two types of secondary rearrangement events occur at approximately equal frequency. Approximately 30% of the VH to DJH joins lead to the production of mu heavy chains providing support for a regulated model of allelic exclusion. Like pre-B cell lines from other origins, the 300-19 line preferentially utilized VH gene segments from the more JH-proximal (3') families to form VHDJH rearrangements. However, the VH segments preferentially employed by 300-19 were from a different family than those previously demonstrated to be utilized by pre-B lines of BALB/c origin; we relate these different utilization patterns to differences in the organization of the more 3' VH families between the two strains. The initial DJH rearrangements of the 300-19 line employed more 3' (JH-proximal) D segments; however, the DJH replacements preferentially employed the most 5' D segment. We discuss this phenomenon in the context of a mechanism which may target recombinase to regions of the chromosome more 5' to the D locus (VH-containing regions) once an initial DJH complex is formed.

Dopamine inhibits the aldosterone response to upright posture

Aldosterone secretion in man is stimulated by potassium, ACTH, and angiotensin II and is inhibited by dopamine (DA). In normal sodium-replete supine individuals, aldosterone secretion is under maximum tonic inhibition by DA. Dopaminergic control of aldosterone secretion is modified by dietary sodium depletion. To determine the physiological significance of dopaminergic inhibition of aldosterone secretion, we studied the effect of DA on the aldosterone response to upright posture. Twelve normal men were studied while eating an ad libitum sodium diet, and the effect of DA was determined in the supine and upright positions. Plasma aldosterone (PAC), plasma cortisol (F), plasma aldosterone-stimulating factor (ASF), PRA, and blood pressure were measured while the men were supine and after 4 h of upright posture during an infusion of 5% dextrose vehicle and during a DA infusion of 4.0 micrograms/kg X min. The men also were studied as a time control in the supine position while receiving vehicle or DA. PAC increased from a mean basal value of 20.4 +/- 3.2 ng/dl (+/- SE) by 25.9 +/- 5.1 ng/dl to a peak of 44.4 +/- 2.4 ng/dl in response to upright posture during vehicle infusion. The PAC response to upright posture was reduced to 7.4 +/- 1.8 ng/dl (P less than 0.05) when DA was infused. The increase in PRA with upright posture was 3.7 +/- 1.3 ng/ml X h during the vehicle infusion and 4.1 +/- 1.1 ng/ml X h (P = NS) during the DA infusion. ASF, F, and blood pressure were not altered by upright posture and DA. PAC did not change in the six men infused with DA while supine. Therefore, DA inhibits upright aldosterone responses without affecting PRA, ASF, or F.

The human IgA system: a reassessment

In healthy adults the total daily production of secretory and serum IgA exceeds that of other immunoglobulin classes. Secretory and serum IgA display features of mutual independence: they are represented by molecules with different physiochemical and immunochemical properties and antibody activities and are produced by cells with different organ distributions. Secretory and serum IgA also exhibit different effector functions: interaction of secretory IgA with environmental antigens results in prevention of the penetration of such antigens by a variety of mechanisms. Although the function of polymeric serum IgA antibodies in certain animal species involves elimination of antigenic substances by noninflammatory means, the primary function of serum IgA remains unknown. It is proposed that in humans monomeric serum IgA (which prevents activation of the complement systems, inhibits phagocytosis and antibody-dependent cellular cytotoxicity) may protect endogenous antigens expressed on various cells and tissues by preventing their interaction with humoral and cellular immune mechanisms that may lead to tissue damage.

Circulating immune complexes and immunoglobulin A rheumatoid factor in patients with mesangial immunoglobulin A nephropathies

Circulating immune complexes (CIC) containing IgA and C3 were elevated in 48% of IgA nephropathy patients; IgA1 was the predominant subclass. IgA1-IgG CIC were detected in 44%, IgA2-IgG CIC in 7%, and IgM-IgA1 CIC in 16% of the patients. No IgM-IgA2 CIC were detectable. Sucrose gradient ultracentrifugation indicated that IgG-IgA1 CIC were predominantly of intermediate (13-19S) size whereas IgA1-C3 CIC sedimented from 11S to 19S. At acid pH, isolated CIC revealed the presence of substantial amounts of 7S IgA. One third of the patients had elevated serum IgA rheumatoid factor (RF) of both polymeric and monomeric forms despite normal levels of IgM-RF; 87% of patients with elevated IgA-RF had IgA1-IgG CIC. These results indicate that the IgA1 component of CIC in patients with IgA nephropathy is not necessarily of mucosal origin and suggest that a portion of these CIC consists of IgA RF immunologically complexed with autologous IgG.

Temperature-dependent surface charge modulation, membrane fluidity, and metastatic ability of L51178Y lymphoma

The isoelectric characteristics of Y/ES (metastasizing) and Y/E (non-metastasizing) DBA/2 lymphoma, and the effects of reducing the ambient temperature on the surface charge density of the cells have been investigated. The change in the surface charge density caused by lowering the temperature is greater in the Y/ES than in the Y/E cells. It is suggested that the protrusion of membrane proteins into the aqueous phase, the consequent expression of cell surface charge, and the temperature-dependent modulation of the latter may be related to the lateral mosaicism of membrane lipids and reflect the state of membrane fluidity.

Regulated progression of a cultured pre-B-cell line to the B-cell stage

The variable (V) regions of heavy and light immunoglobulin chains are encoded by multiple germline DNA elements which are assembled into complete variable-region genes in precursor(pre-) B lymphocytes. The heavy-chain V region (VH) is assembled from three separate germline DNA elements, the variable (VH), diversity (D) and joining (JH) segments; whereas light-chain variable regions of either the kappa or lambda type are assembled from two elements, the VL and JL. Analysis of tumour cell lines or sorted cell populations which represent early and late pre-B cells has suggested that heavy-chain assembly and expression generally precedes that of light chains; but, primarily because of the lack of appropriate model systems to study the phenomenon, the mechanism and significance of this apparently orderly differentiation process are much debated. Here we describe for the first time a transformed cell line, 300-19, which sequentially undergoes all of the immunoglobulin gene rearrangement and expression events associated with the differentiation of pre-B cells to surface immunoglobulin-positive B lymphocytes. Analysis of the in vitro differentiation of 300-19 cells provides direct evidence for distinct differentiation phases of first VH and subsequently VL assembly during B-cell differentiation. Furthermore, these analyses suggest that the mu heavy chain, resulting from a productive VHDJH rearrangement, has both a positive and a negative regulatory role in mediating this ordered differentiation process, that is, signalling the cessation of VH gene assembly and simultaneously signalling the onset of VL assembly.

Absorption, metabolism, and excretion studies of carbon 14- and tritium-labeled derivatives of a ketomethylene containing tripeptide

Tritium and Carbon 14 analogs of the angiotensin converting enzyme inhibitor ketoACE were synthesized and their oral absorption, metabolism and excretion in rats were investigated. KetoACE, a ketomethylene analog of the tripeptide Bz-Phe-Gly-Pro, was slowly absorbed at a 35% level upon oral administration. It is rapidly eliminated from the blood with a half-life of about 10 minutes. Its excretion is primarily via the bile duct and it is excreted as 80% unchanged drug. The only identified metabolite consisting of 5-10% of the excreted radioactivity was determined to be the reduced ketoACE in which the ketone group was reduced to a hydroxyl.

Pro-opiocortin peptides in rat cerebrospinal fluid

Cerebrospinal fluid (CSF) taken from rats implanted with chronic cisternal cannulae was subjected to gel filtration chromatography on Sephadex G-50. Fractions were monitored using radioimmunoassays for N-terminal pro-opiocortin (N-POC), gamma 3-melanotropin (gamma 3-MSH), C-terminal adrenocorticotropin (C-ACTH), alpha-endorphin, beta-endorphin, gamma-lipotropin (gamma-LPH) and alpha-MSH. Two peaks which corresponded in elution position to rat N-POC (1-74) and gamma 3-MSH were detected. The major C-ACTH-immunoreactive (IR) peak was found to correspond to 14k ACTH. While no alpha-endorphin immunoreactivity was detected in rat CSF, three beta-endorphin-IR peaks were identified in positions expected for beta-LPH, beta-endorphin (1-31) and beta-endorphin (1-27), as well as a major peak of activity with the elution characteristics and cross-reactivity of rat gamma-LPH. HPLC of the alpha-MSH-IR material in rat CSF revealed the presence of a major peak of immunoreactivity whose retention time did not correspond to the known oxidised and reduced forms of alpha-MSH and its desacetylated and diacetylated derivatives. The identity of this peak is unknown.

Pro-enkephalin peptides possessing Met-enkephalin-Arg6-Gly7-Leu8-immunoreactivity in rat CSF, striatum and adrenal gland

Cerebrospinal fluid (CSF) taken from rats implanted with chronic cisternal cannulae and extracts prepared from rat adrenal gland and striatum were subjected to Sephadex G-50 chromatography and HPLC. Fractions were monitored using specific radioimmunoassays (RIA) for the pentapeptide methionine enkephalin (Met-Enk) and methionine enkephalin-Arg6-Gly7-Leu8 (Met-EnkRGL). In rat CSF, striatum and adrenal gland, three Met-EnkRGL-immunoreactive (IR) peaks of Mrs 8000, 5000 and 1000 daltons were detected. The same peaks were also found to possess Met-Enk-immunoreactivity after enzyme digestion of Sephadex G-50 fractions with trypsin and carboxypeptidase B (CPB), suggesting their derivation from proenkephalin. HPLC of the 8K and 5K peaks on a column of Ultrapore RPSC showed them to elute discretely with similar retention times, indicative of hydrophobic peptides of large molecular weight. Their similar hydrophobicities yet significant separation during gel filtration would suggest that the 8K and 5K peptides are structurally closely related yet different with respect to their molecular weights. HPLC of the small molecular weight material from rat striatum and adrenal gland revealed the presence of Met-EnkRGL and Met-EnkRGL sulphoxide in both tissues. In rat striatum Met-Enk and its sulphoxide were also detected. The oxidised pentapeptide was found to be present in rat CSF, together with two unidentified small molecular weight Met-Enk-IR peaks detected without prior enzyme digestion of fractions. The small molecular weight Met-EnkRGL-IR material in rat CSF was found to be comprised of two unknown peptides which were less hydrophobic than Met-EnkRGL and its sulphoxide derivative.

Lymphocytotoxic antibodies in leukemic patients treated with bone marrow transplantation

Lymphocytotoxic antibodies were studied sequentially in a series of 42 patients with leukemia who received a bone marrow graft. Of these patients, 38% had cytotoxic antibodies before bone marrow transplantation (BMT). After BMT the antibody status changed with time, but 62% of the patients had antibodies at some time after BMT. During the first 10 weeks after BMT, 40% of the patients had antibodies. Thereafter the frequency rose to 50% and remained at that level beyond one year after BMT. In successful grafts the gamma globulins are of donor origin six months after BMT; thus donor B cells are capable of forming lymphocytotoxic antibodies even when the immune system is suppressed by cyclosporine. The antibodies had recognizable HLA specificity in about half the cases before and after BMT. When donor and patient were HLA-identical, HLA specificity did not correspond to donor/recipient antigens. In two cases in which the donor was matched for only one haplotype, antibodies formed by recipient cells, active against donor HLA antigens, were found.

Influence of basic and branched chain amino acid interactions on the lysine and valine requirements of young turkeys

Two experiments were conducted to determine the influence of amino acid interactions on the lysine and valine adequacy of a low protein diet fed to Large White turkeys from 7 to 19 days of age. Corn-soybean meal diets containing 22 and 30% protein served as controls in both experiments. Test diets involved supplementation of the 22% protein diet with several essential amino acid mixtures. Each diet was fed ad libitum to two pens of eight males and two pens of eight females in each of three trials, except that the 22% protein control diet was fed to four and two pens of each sex per trial in Experiments 1 and 2, respectively. Experiment 1 varied the levels of lysine (0, .60, and 1.20%) and arginine (0, .64, and 1.28%) included in the amino acid mixture. A decrease in supplemental lysine from .60 to 0% reduced weight gain and feed efficiency by 8.6 and 2.4%, respectively. The lysine deficiency was not exacerbated by arginine supplementation up to 179% of the requirement. The effects of altering the leucine (0, .54, and 1.08%) and isoleucine (0 and .4%) contents of the amino acid mixture on the valine requirement were investigated in Experiment 2. Leucine and isoleucine supplementation of diets containing 1.25% valine acted independently to reduce weight gain and feed intake, but the depressions were reversed with the addition of .44% valine. Maximum weight gain and feed efficiency were not achieved with diets containing 1.25% valine and no added leucine or isoleucine, which were indicative of a true valine deficiency in the basal 22% protein diet.(ABSTRACT TRUNCATED AT 250 WORDS)

Growth hormone releasing factor (GRF) immunoreactivity in human and rat gastrointestinal tract and pancreas

Rabbit antisera were raised against a synthetic growth hormone releasing factor, which was originally isolated from a human pancreatic endocrine tumor (hpGRF-44). The antisera obtained showed no significant cross-reactivity with a variety of neurohormonal peptides. In addition to its occurrence in the human, but not in the rat, hypothalamus, hpGRF-44-like immunoreactivity was identified in human gastric antrum and human as well as rat pancreatic islets, using an indirect immunoperoxidase technique. Staining of serial sections and double staining revealed that in the gastric antrum the immunoreactivity was largely confined to gastrin (G) cells, whereas in pancreatic islets polypeptide (pp) cells were reactive. The physiological significance of these findings remains to be established.

A rabbit helper T cell clone reactive against group-specific streptococcal carbohydrate

Cloned rabbit T cell lines specific for the group-specific carbohydrate of group C streptococcus were established to study T cell responses to this antigen. T cell lines and clones of these lines were prepared from peripheral blood lymphoid cells of animals previously hyperimmunized with group C streptococcal vaccine. All cell lines studied were antigen specific in that they proliferated in the presence of group C but not group A vaccine. Three clones from one rabbit showed strong proliferation in the presence of soluble group C carbohydrate, in addition to the particulate vaccine. One of these clones, 5317.1, upon additional characterization, was shown to possess helper activity in that it induced autologous B cells to produce anti-carbohydrate antibody. Interestingly, B cells could not be stimulated by this carbohydrate-responsive clone to produce anti-carbohydrate antibody in the presence of soluble carbohydrate; the intact vaccine was required to demonstrate the helper effect of the clone. Phenotypic characterization of this clone with a panel of monoclonal antibodies indicated that it was of the T1 subpopulation of peripheral T cells. No suppressor activity was observed for any of the lines studied. Although the use of outbred animals in T cell cloning experiments has certain disadvantages, the present results indicate that cloned rabbit T cells may be useful tools for the elucidation of phenotypic and functional differences of rabbit T cell subsets.

A rabbit helper T cell clone reactive against group-specific streptococcal carbohydrate

Cloned rabbit T cell lines specific for the group-specific carbohydrate of group C streptococcus were established to study T cell responses to this antigen. T cell lines and clones of these lines were prepared from peripheral blood lymphoid cells of animals previously hyperimmunized with group C streptococcal vaccine. All cell lines studied were antigen specific in that they proliferated in the presence of group C but not group A vaccine. Three clones from one rabbit showed strong proliferation in the presence of soluble group C carbohydrate, in addition to the particulate vaccine. One of these clones, 5317.1, upon additional characterization, was shown to possess helper activity in that it induced autologous B cells to produce anti-carbohydrate antibody. Interestingly, B cells could not be stimulated by this carbohydrate-responsive clone to produce anti-carbohydrate antibody in the presence of soluble carbohydrate; the intact vaccine was required to demonstrate the helper effect of the clone. Phenotypic characterization of this clone with a panel of monoclonal antibodies indicated that it was of the T1 subpopulation of peripheral T cells. No suppressor activity was observed for any of the lines studied. Although the use of outbred animals in T cell cloning experiments has certain disadvantages, the present results indicate that cloned rabbit T cells may be useful tools for the elucidation of phenotypic and functional differences of rabbit T cell subsets.

Endorphin-related peptides in rat cerebrospinal fluid

Cerebrospinal fluid (CSF) samples were taken from rats implanted with chronic cisternal cannulae and assayed for methionine-enkephalin, beta-endorphin and corticotropin (ACTH). Immobilization stress had little apparent effect on immunoreactive levels of the peptides in the CSF. Gel chromatographic analysis of the beta-endorphin- and ACTH-immunoreactive profiles in rat CSF revealed several peaks. beta-Endorphin-immunoreactive peaks were present at the expected positions of pro-opiocortin, beta-lipotropin and beta-endorphin. ACTH-immunoreactive peaks eluted at positions corresponding to pro-opiocortin, the 20-23K ACTH biosynthetic intermediate, 14K ACTH, and 4.5K ACTH. These results suggest that rat CSF contains peptides of the pro-opiocortin family similar to those previously described in rat pituitary.

The role of rabbit immunoglobulin allotypes in an immune network

The expression of latent allotypes is a well documented phenomenon in rabbits. Speculation about their molecular genetic basis and the mechanisms that control expression of these unexpected markers lead inevitably to questions about the Ig gene complement of the rabbit. This central question is under current study using probes derived originally from the mRNA of rabbit-mouse hybridomas secreting rabbit Ig chains. Some of the basic features of rabbit Ig genes are already clear from these studies, and DNA fragments that might encode latent allotypes have been identified with the first set of probes. Further gene closing sequencing should shortly provide a definitive answer to the question of latent allotypy and will also provide a detailed understanding of nominal Ig expression in rabbits.

Secretion of pro-opiocortin peptides from isolated perfused rat pars intermedia cells

The perfused, isolated, pituitary cell column was used to measure the release of alpha-melanotropin (alpha-MSH)-like immunoreactivity (LI), carboxyl terminal corticotropin (C-ACTH)-LI, gamma-lipotropin (gamma-LPH)-LI, alpha-endorphin-LI, beta-endorphin-LI and amino-terminal pro-opiocortin (N-POC)-LI from rat pars intermedia (PI) cells. Concomitant secretion of all PI peptides was observed during basal release and in response to all applied stimuli. Dopamine (DA) caused a dose-dependent (10(-9)-10(-5) M) simultaneous inhibition of peptide release which was antagonised by haloperidol. Isoprenaline stimulated the release of PI peptides in a parallel, dose-related (10(-10)-10(-6) M) manner and was blocked by propranolol. Stimulation of peptide secretion caused by low concentrations (10(-8) M), of adrenaline (AD) and noradrenaline (NA) changed to inhibition at high concentrations (10(-5) M) whereas intermediate concentrations (10(-6), 10(-7) M) possessed both inhibitory and excitatory effects. A 45 mM solution of K+ ions stimulated the release of PI peptides and both the K+-stimulated secretion and basal secretion were Ca++-dependent. MSH-release-inhibiting factor (MIF) and 5-hydroxytryptamine (5-HT) failed to alter peptide secretion from the perfused PI cells. We conclude that pro-opiocortin (POC) peptides are released concomitantly from rat PI cells and that biogenic amines are involved in their release.

Isolation and characterisation of genomic and cDNA clones for an androgen-regulated secretory protein of rat seminal vesicles

Testosterone controls the synthesis of seminal vesicle protein F in male rats by regulating the cellular concentration of its mRNA (mRNAF). Phage lambda recombinants have been isolated containing the complete F gene. In addition plasmids have been constructed containing cDNAF sequences some of which are probably full-length (approximately 700 bp). Detailed restriction mapping shows that the F gene is 1.7 kbp long and contains approximately 1.0 kbp of intervening sequence arranged in at least two introns (420 bp and 600 bp). Part of cDNAF has been sequenced showing that the terminal 125 bp of the 3' untranslated region of mRNAF has substantial (greater than 70%) sequence homology with the 3' end of the mRNA coding for another androgen-dependent seminal vesicle protein (protein S). The cloned F gene has been detected in liver and seminal vesicle DNA along with an homologous but structurally different gene. The hormonal control of mRNAF was examined with cDNAF. A pronounced (approximately 3000-fold) differential response to testosterone was observed.

An investigation of N-terminal pro-opiocortin peptides in the rat pituitary

Extracts of neurointermediate lobe (NIL) and anterior lobe (AL) of the rat pituitary, and material released from perfused rat pars distalis (PD) and pars intermedia (PI) cells were gel chromatographed and monitored using three antisera, each recognizing different regions of the non-corticotropin (ACTH)-lipotropin (LPH) portion of pro-opiocortin (POC). Two peaks (termed N-POC I) which emerged close to the elution position of rat beta-LPH were detected. The first peak was reduced significantly in the PI. Two smaller N-POC fragments which eluted near beta-endorphin were detected only in extracts and secretions of intermediate lobe tissue. One peak cross-reacted in the gamma 3-melanotropin (MSH) assay (N-POC III) whereas the other peak possessed amino (N)-terminal N-POC immunoreactivity (N-POC II). The results demonstrated differences in the distribution and nature of N-POC peptides released and extracted from the PD and PI of the rat pituitary, and suggest that the enzymic processing of N-POC is different in the two pituitary lobes.

Relative deficiencies of amino acids and nitrogen per se in low protein diets for young turkeys

Three experiments were conducted to determine the relative deficiencies of lysine, threonine, valine, and nitrogen per se in a low protein diet composed primarily of corn, soybean meal, and .3% added DL-methionine fed to young turkeys. Diets containing 22, 26, and 30% protein served as controls. A mixture of amino acids (AA) was added to the 22% protein diet. Additional diets were formulated by individually removing lysine, threonine, or valine from the AA mixture and by adding 4% glutamic acid to each to form a 5 X 2 design exclusive of 26 and 30% protein diets. In each experiment, each diet was fed ad libitum to two pens of nine male poults and two pens of nine female poults of a medium body-size variety from 8 to 19 or 20 days of age. Body weight gains and feed consumptions were increased (P less than .001) by supplementing the 22% protein diet with the AA mixture or by increasing the protein level to 26 or 30%. Removal of either lysine, threonine, or valine from the AA mixture produced body weight gains and feed efficiencies smaller (P less than .001) than from the fully supplemented diets but greater (P less than .05) than from the unsupplemented diets. The addition of 4% glutamic acid to the diets failed to improve performance, indicating that nitrogen per se is not the limiting factor for growth. From these results, it is postulated that sulfur AA appear more deficient than either lysine, threonine, or valine in the 22% protein corn-soybean meal diet containing .3% added methionine.

Long lived nonadherent rabbit macrophages obtained from spleen cell cultures

During the preparation of rabbit-mouse hybridomas, an unusual degree of cellular proliferation and a high level of rabbit immunoglobulin secretion in culture was noted. The proliferation seemed to be dependent on the use of relatively high levels (10%) of fetal bovine serum because it was not seen when spleen cells were cultured using either horse serum or autologous serum in a variety of media. The peak of the proliferative response occurs at 7 to 10 d in culture, after which the lymphoblast population dies rapidly, leaving a large, granular, nonadherent cell as the predominant component in the culture. These cells did not seem to divide further but persisted in very gradually diminishing numbers for many months. This long lived cell has been characterized as a nonadherent macrophage by its morphology, intense esterase staining, expression of an Fc receptor for rabbit IgG, phagocytosis of latex particles and opsonized sheep erythrocytes, and mediation of antibody dependent cell mediated cytotoxicity on chicken erythrocytes.

Differentiation antigens identify subpopulations of rabbit T and B lymphocytes. Definition by flow cytometry

A panel of six monoclonal antibodies produced against cell surface glycoproteins of a rabbit T lymphocyte line was used with flow cytometry to define rabbit lymphocyte subpopulations. Four thymocyte populations were characterized by size and expression of cell surface antigens and appear to represent stages in thymocyte differentiation. Rabbit spleen contained five subpopulations: two of T lineage, two of B, and a null cell subset. Bimodal distribution of staining of thymocytes and peripheral T cells was observed using an antibody (9AE10) directed against a Thy-1 analogue in the rabbit, suggesting two separate T cell lineages. One of the monoclonal reagents, L11/135, reacted strongly with peripheral rabbit T cells as shown by two-color immunofluorescence. In functional studies, only the L11/135-bearing cells responded to the T cell mitogens concanavalin A and phytohemagglutinin and to allogeneic splenocytes. The thymocyte subpopulations and the peripheral T and B cell subsets differ from those described in mouse and man.

Effect of dietary protein and energy on broiler performance and production costs

Varying levels of dietary protein (16, 20, 24, 28, 32, 36%) and energy (2600, 2800, 3000, 3200, 3400, 3600 kcal [metabolizable energy] ME/kg) were fed in a factorial arrangement to broilers to determine the effect of alteration in nutrient density on performance and economic traits. Body weight and feed efficiency improved with increased dietary protein or energy. However, a significant interaction between protein and energy indicated the importance of a balanced energy: protein ratio to achieve optimum performance. Sex differences in protein requirements were observed for 49-day body weights. Returns over feed costs remained essentially constant, providing a balance between dietary protein and energy was maintained. However, an increase above 28% crude protein or 3400 kcal ME/kg resulted in reduced returns as did excessive quantities of one nutrient relative to the other. Male broilers were able to accommodate a higher level of dietary protein (24%) than female broilers (20%) before returns were reduced. Regression equations were derived for prediction of performance and economic parameters. Reliable estimates were obtained with the inclusion of protein or energy intake in addition to diet composition.

Effect of dietary protein and energy on broiler carcass composition and efficiency of nutrient utilization

Day-old broilers were offered diets varying in dietary protein (16, 20, 24, 28, 32, 36%) and energy (2600, 2800, 3000, 3200, 3400, 3600 kcal [metabolizable energy] ME/kg) to 49 days of age to determine the effect of alteration in nutrient density on carcass composition and efficiency of nutrient utilization. Abdominal and total carcass fat contents responded similarly to alterations in dietary protein and energy, whether expressed on a percentage or absolute weight basis. However, maximum protein deposition occurred with the 20% crude protein diet, in contrast to the increase in percent carcass protein observed above this level. Although percent carcass protein decreased throughout the energy range tested, absolute carcass protein remained constant regardless of the dietary energy level. Dietary protein exerted similar effects on both absolute and percent carcass moisture. However, an increase in dietary energy resulted in a decrease in percent carcass moisture and an increase in absolute carcass moisture. Protein utilization decreased with each increment of dietary protein but increases in dietary energy resulted in small increases in protein utilization throughout the range tested. Changes in dietary protein and energy resulted in small differences in efficiency of energy utilization. Regression equations derived for carcass composition demonstrated that although diet composition is inadequate as a predictor of carcass parameters, the addition of carcass moisture (%) to the equation improves the reliability of the estimate. Equations for the prediction of nutrient utilization from diet composition are also presented.

Urology/sexuality clinic: results of counseling of 67 men

Of 67 psychogenically impotent men encountered in a new Urology/Sexuality Clinic during its first 36 months of operation at the University of California Medical Center in San Francisco, 52 returned for more than one urologic counseling visit, rendered individually by the senior author in all cases. There was a 79 percent success rate in the form of reinstatement of sexual activity, generally within three sessions, at weekly intervals. Success appeared, for the most part, unrelated to age, to previous treatment elsewhere, or even to major medical or surgical problems among some of these men who ranged in age from 18 to 78 years.

Microdetermination of rabbit immunoglobulin allotypes by ELISA using specific antibodies conjugated with peroxidase or with biotin

Enzyme-linked immunoadsorbent assays (ELISA) specific for the allotypes of rabbit heavy chain variable region (group a) and light chain constant region (group b) have been developed. These assays utilize affinity-purified allogeneic anti-allotype antibodies to coat polyvinyl microtiter plates. After test samples are added to the plates, the same affinity-purified antibody, coupled to the enzyme peroxidase, is used to detect binding of allotype-positive IgG samples to the coated plate. These assays can detect as little as 40 ng/ml of IgG of the appropriate allotype; the assays are highly specific and allow quantitative determination of allotype-defined IgG samples. In addition, the procedure can be modified by coupling of the antibody with biotin followed by development with avidin-peroxidase; this adaptation avoids the difficulties encountered in antibody-peroxidase conjugations. The ELISA assay is not influenced by the presence of anti-allotype antibody in the test sample, giving a distinct advantage over solid-phase radioimmunoassay procedures conventionally used for the quantitative determination of rabbit allotypes.

Ambiguity and implicature in children's discourse comprehension

21 first graders and 20 third graders were told to pick drawings of clowns out of an array on the basis of ambiguous messages. One of the messages could be taken to refer to either of two clowns, depending on which interpretive strategy the child employed. The other message could be given no definite interpretation. Although 23 of 41 children refused to make a definite choice for the second message, 31 specified choices for the first message. First graders applied an Antecedence Maxim strategy. Third graders used a Quantity Maxim strategy.

Shared idiotypes among anti-albumin antibodies of different species

A system designed to detect plasma cells that produce antibodies directed at autologous idiotypic determinants of anti-human serum albumin (HSA) antibodies in rabbits was used to determine whether anti-HSA antibodies of horse, goat, swine and chicken origin were cross-reactive with rabbit antibodies of the same specificity. Fluorochrome-tagged anti-HSA preparations of these diverse species were used to stain splenic plasma cells of HSA-immunized rabbits and a similarly immunized chicken. The degree of idiotypic cross-reactivity, as detected by binding of anti-HSA antibodies to anti-idiotype within plasma cells of HSA-immunized animals, was sometimes equal to autologous staining. However chicken anti-HSA, the most phylogenetically distant idiotype examined, was demonstrably less cross-reactive than that obtained from the other species. Likewise, chicken plasma cells usually did not bind mammalian anti-HSA antibodies to an appreciable degree, as compared with autologous staining. These findings provide evidence for serologic and possibly structural similarities of antibodies of the same specificity from different species.

beta-Adrenergic stimulation of the release of ACTH- and LPH-related peptides from the pars intermedia of the rat pituitary gland

The intermediate lobe of the rat pituitary gland produces a series of peptides related to ACTH and LPH. The spontaneous and isoproterenol-stimulated release of such peptides was studied during in vitro superfusion of rat neurointermediate lobes with Krebs-Ringer medium. Products released into the superfusion medium were quantified by direct measurement or after chromatography on Sephadex G-50. ACTH bioactivity was determined by use of adrenal cortical cell suspension assay. In addition, NH2-terminal ACTH, CO2H-terminal ACTH, alpha-MSH and beta-endorphin radioimmunoassays were used. The results show that 1. neurointermediate lobes of rats secret spontaneously various ACTH- and LPH-related peptides in amounts proportional to the amounts in which these peptides are found in extracts of the neurointermediate lobe; 2. the beta-adrenergic agonist, isoproterenol, stimulated the spontaneous release of various peptides, including alpha-MSH, ACTH, CLIP, glycosylated CLIP, and beta-endorphin-like peptides; 3. isoproterenol induced a dose-dependent (10(-9)-10(-7) M), parallel increase in the release of alpha-MSH and ACTH following similar time courses and showing identical EC50 values (about 10(-8)M). Although the spontaneous release of alpha-MSH and ACTH from rat neurointermediate lobes is not strictly coupled under the conditions used in this study, isoproterenol seems to affect the spontaneous release of these peptides to the same relative extent.

Atypical mycobacteria as the probable cause of positive tuberculin reactions in squirrel monkeys (Saimiri sciureus)

Three of 275 squirrel monkeys (Saimiri sciureus) demonstrated a positive reaction to Koch's old tuberculin within 72 hours after the test. The animals were again positive when retested 1 week later. Two of the monkeys were killed and necropsied. There was no gross nor histologic evidence of tuberculosis. Organisms were cultured from liver, spleen, and mediastinal lymph node. These were identified as Runyon Group II mycobacteria, Mycobacteria gordoneae.

Distribution of adrenocorticotrophic and lipotrophic peptides in the rat

Intermediate and anterior lobes from the pituitary glands of female Wistar rats were freshly dissected and chromatographed on Sephedex G-50 and BioGel P6. Fractions were monitored with radioimmunoassays for NH2- and CO2H-terminal adrenocorticotrophin (ACTH), alpha-melanocyte-stimulating hormone (alpha-MSH), and alpha- and beta-endorphin. A large molecular weight, glycosylated form of corticotrophin-like intermediate lobe peptide (CLIP) which we have termed big CLIP, and a beta-MSH-like molecule were identified in the pars intermedia and in both lobes, a major peak of activity with the elution characteristics and cross-reactivity of gamma-lipotrophic hormone (gamma-LPH) was detected. In the pars distalis, the larger peptides 1-39 ACTH and beta-LPH predominated, whereas in the pars intermedia, the smaller peptides alpha-MSH, CLIP, beta- and alpha-endorphin were more abundant. Chromatography of rat plasma revealed peaks of immunoreactivity in the corresponding positions to those detected in the pituitary gland.

Treatment of parotid neoplasms

Over a 25-year period 124 patients were admitted to St. Joseph's Hospital, Toronto with parotid neoplasms; 102 had benign and 22 had malignant lesions. Of 75 pleomorphic adenomas, 26 were enucleated and 11 of them (42%) recurred; no instances of recurrence followed parotidectomy. In 19 patients with Warthin's tumour there were no recurrences following any of the methods of excision. Mucoepidermoid carcinoma occurred in nine patients; eight tumours were of low-grade malignancy. All were treated by parotidectomy and there were no recurrences. Four patients had malignant mixed tumour--two with long-standing parotid masses; in three patients this malignant tumour occurred years after regional radiotherapy. Facial weakness was permanent in three patients after total parotidectomy. The correct treatment of parotid neoplasms is superficial parotidectomy or, for deep lobe tumours, total parotidectomy. Radiotherapy is used for unresectable or suspected residual carcinoma.