15038 studies
Cholinergic neurotransmission exerts a physiological control on GH secretion. Pirenzepine (Pz), an antagonist of muscarinic receptors, by enhancing hypothalamic somatostatin release, inhibits stimulated GH secretion in normal subjects but not in acro…
An 18-kDa hemagglutinin which possesses the property of inducing both aggregation of amebocytes and agglutination of erythrocytes has been isolated from Limulus polyphemus amebocytes and purified by ion exchange chromatography. This nonglycosylated,…
Glycyl-L-histidyl-L-lysine-copper (II) complex (GHK-Cu) is a naturally occurring tripeptide with potential healing properties. We studied the effect of GHK-Cu on the synthesis of glycosaminoglycans (GAGs) by normal human fibroblasts in culture. Cells…
Lymphoepithelial complexes known as thymic "nurse" cells (TNC) have been isolated and described in the thymus of several animal species including man. Most of the investigations on TNC have been carried out in enzymatically digested thymuses in which…
Serum concentrations of thymosin alpha-1 (TA-1), an immunoregulatory peptide, were assayed in patients with chronic hepatitis B infection and volunteer blood donor controls. Coded samples were tested using a radioimmunoassay. The TA-1 concentrations…
We have investigated the effects of a combination in vivo treatment with thymosin alpha 1 (TA1) and murine alpha/beta interferon (IFN) on natural killer (NK) activity and on tumor growth in B-16 melanoma tumor-bearing mice. The results indicated that…
To develop a model of how stress and other psychosocial constructs may interact to explain recurrences of genital herpes, assessments of major and minor life stress, locus of control, arousal or stimulation seeking, and social support were given to 1…
A study was made of the level of corticosterone in mouse blood plasma after 4-time daily administration of thymopthin (a drug containing 1% of thymosin-alpha 1, synthesized in the All-Union Research Institute of Technology of Blood Substitution and H…
The octapeptide corresponding to human interferon-alpha 2 (Hu IFN-alpha 2) sequence 131-138 has high affinity to murine thymocyte receptors (Kd = 4.2 x 10(-12) M, about 700 receptors per cell). The peptide receptor binding is inhibited by both Hu rIF…
Prothymosin alpha is a highly acidic protein which lacks an amino-terminal signal peptide, yet was once thought to be a precursor for thymosin alpha 1, a putative peptide hormone secreted by the thymus. Here, two lines of evidence are presented that…
We have investigated the effects of interleukin 2 (IL-2) on cytotoxic activity of spleen lymphocytes, from normal and cyclophosphamide (200 mg/kg) or B-16 melanoma suppressed mice, after in vitro or in vivo pretreatment with thymosin alpha 1 (TA1). T…
Monoclonal antibodies have been generated against a synthetic peptide of the nef protein of human immunodeficiency virus type 1 (HIV-1) in order to further characterize the biochemical and functional nature of this protein and its role in the control…
A fragment analog, [D-Arg30]prothymosin alpha fragment 1-30, containing D-arginine in place of arginine residue at position 30 was synthesized by the liquid phase procedure and studied for immunological effect on the impaired blastogenic response of…
Growth of normal and malignant cells is controlled by the interplay of several hormones and growth factors present in the body. The growth of the human breast cancer cell line MCF-7 is stimulated in vitro by estradiol which has been shown to induce t…
Rat prothymosin alpha fragment 29-111, an 83-residue polypeptide corresponding to desthymosin alpha 1-prothymosin alpha, has been synthesized by a solid-phase method. Hydrogen fluoride was used to deprotect and cleave the peptide from the resin. The…
Thymic peptides play an important role in aging and immune regulation, but little is known about their relationship to psychosocial factors. One thymic fraction, thymosin-alpha 1 (TSN-alpha 1) may be of particular interest given its hypothesized role…
Chronic hepatitis B is a severe and frequently progressive disease. We assessed the safety and efficacy of thymosin fraction 5 and thymosin-alpha 1 in a prospective, placebo-controlled trial in 12 patients with chronic hepatitis B. All patients had h…
A fragment corresponding to N-terminal octaeicosapeptide of rat parathymosin alpha was synthesized by assembling 5 peptide fragments, followed by deprotection with 1 M trifluoromethanesulfonic acid-thioanisole (molar ratio 1:1) in trifluoroacetic aci…
D-Amino acid substitutions in the anti-inflammatory/antipyretic Ac-alpha-MSH(11-13)-NH2 tripeptide of Ac-alpha-MSH(1-13)-NH2 were made and the altered peptides were injected in mice treated with picryl chloride. Ear swelling, measured 3 and 6 h after…
Degradation of a regulatory peptide ACTH(4-10) and its synthetic analog semax in rat blood and serum was studied using high-performance liquid chromatography. About one third to one half of the serum degrading activity could be ascribed to bestatin-s…