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Biomedical subjects

S Jackson

Publications and source records attributed to S Jackson.

At least 325 records · Page 18Linked to original sources
PubMed1983

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.

Amino Acids↗
PubMed1982

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.

Animals↗
PubMed1982

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.

Animals↗
PubMed1982

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.

Animal Feed↗
PubMed1982

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.

Adolescent↗
PubMed1981

Nature and control of peptide release from the pars intermedia.

Pro-opiocortin, the precursor of ACTH, LPH and gamma-MSH, is biosynthesized in both the cells of the pars intermedia and the corticotrophs of the pars distalis. In the pars distalis its processing does not vary significantly from species to species whereas in the pars intermedia large differences occur. The release of ACTH, beta-LPH and pro-gamma-MSH from the corticotrophs is under common positive control by hypothalamic corticotropin-releasing factor (CRF) and the nature of the peptides remains unchanged when they are secreted. The release of all five pars intermedia peptides that we have measured in vitro appears to be under tonic dopaminergic inhibition. The secreted peptides have also been identified chromatographically. The lack of unequivocal physiological function in the periphery, the diversity of the pars intermedia peptides and this common control mechanism tend to preclude a simple endocrine role for the pars intermedia. The neural effects of MSH and endorphin are well documented and specific neuronal uptake therefore cannot by dismissed. The absence of pars intermedia in the adult human pituitary suggests that such a site of synthesis of these peptides plays a minor role in learning and behaviour in a species (such as Homo sapiens) that has a highly evolved intelligence and may, instead, need to synthesize the peptides only in the brain.

Adrenocorticotropic Hormone↗
PubMed1981

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.

Animals↗
PubMed1981

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.

Adrenergic beta-Agonists↗
PubMed1981

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.

Animals↗
PubMed1980

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.

Adrenocorticotropic Hormone↗
PubMed1980

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.

Adenolymphoma↗
PubMed1979

Presence of plasma cells binding autologous antibody during an immune response.

Spleen and other lymphoid tissues of rabbits immunized with human serum albumin (HSA) and human lactoferrin (LF) were examined for the presence of cells forming anti-idiotype antibodies. To detect these cells, IgG, F(ab')2, or Fab' of specific antibodies were isolated, fluorochrome-tagged with tetramethylrhodamine isothiocyanate, and used as an idiotypic marker to detect splenic plasma cells that are producing anti-idiotypic antibody. By this procedure, we were able to demonstrate anti-idiotypic cells in surprisingly high numbers. For example, in six rabbits immunized with HSA for periods ranging from 36 to 542 d, the percentage of Ig-positive cells that stained with autologous idiotype ranged from 0.7 to 44; furthermore, cross-reactivity was observed among seven different anti-HSA preparations and two anti-LF antisera. The isotype of anti-idiotypic cells, determined by costaining with fluorescein isothiocyanate-labeled goat Fc-specific anti-rabbit Ig, was shown to be predominantly IgG. These findings provide evidence of the presence of plasma cells producing antibody to autologous idiotype during a vigorous immune response.

Animals↗
PubMed1978

The uptake and redistribution of 241pu within the gonads.

Male and female hamsters and a female rabbit were injected with 241Pu citrate. The hamsters were killed serially at 15 min, 2 hours, 1 day and 10 days after injection, and the rabbit 1 week after injection. The gonads were examined for 241Pu by tissue-section autoradiography. Soon after injection the plutonium was concentrated by the contents of atretic Graafian follicles and by thecal rings in the ovary, but was found to be dispersed throughout the testes. It is suggested that the disperse distribution in the testes which is only seen soon after injection may be an artefact of tissue processing. One day after injection, plutonium was accumulated by macrophages in both the follicles of the ovary and in the interstitial tissue of the testes. Macrophages containing plutonium later migrated away from the aretic ovarian follicles towards the ovarian medulla. This pattern of distribution and redistribution in the ovary is regarded as likely to lower the effective dose from a-emitting plutonium isotopes to the viable oocytes. No migration of macrophages was seen in the testes. Histochemical staining methods revealed the presence of acid protoglycans, including chondroitin sulphate, and glycoproteins at the sites of plutonium concentration in the ovary. These molecules are regarded as likely receptor sites for plutonium. In the testes no acidic carbohydrates were found, and it is suggested that the initial binding site for plutonium may be a compound lipid. This was deduced from the apparent inability of the interstitial tissue of the testes to bind plutonium in situ.

Animals↗
PubMed1978

Blood plasma constituents in 14-week old hypertensive and hypotensive strains of turkeys.

Plasma inorganic phosphorous, glucose, uric acid, total cholesterol, total protein, albumin, alkaline phosphatase, lactic dehydrogenase (LDH), and serum glutamic oxaloacetic transaminase (SGOT) were determined in 14-week old turkeys from lines genetically determined for high and low blood pressure. The turkeys received a commercial grower diet (control), control + 10% animal fat, or control + 10% animal fat and 1% cholesterol. Concentrations of uric acid in plasma were higher (P less than or equal to .05) in the control-diet group than in the other dietary groups, and the high blood pressure line had significantly higher (P less than or equal to .05) concentrations of uric acid in plasma than the low blood pressure line. Turkeys fed the diet containing added cholesterol had higher levels (P less than or equal to .05) of total plasma cholesterol than those receiving the other diets. Alkaline phosphatase levels of plasma were significantly lower (P less than or equal to .05) in the control-diet group than the other dietary groups. There were no other effects within either of the genetic blood pressure lines that indicated blood pressure had any influence on blood plasma constituents other than uric acid, nor was there any indication that dietary treatment had any effect within either blood pressure group. Blood pressure and plasma constituents were not correlated.

Alkaline Phosphatase↗