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PubMedDate not supplied

[The effectiveness of ultralow doses and concentrations of biologically active compounds].

Numerous data of literature are analysed on the biological activity of ultra-low (10(-12)-10(-19) M) concentrations and corresponding doses of same bioregulators. Our own data are presented on the modulation of lymphatic vessel contractility by peptides (thyroliberin, defensin, and tuftsin) in concentrations ranging from 10(-13) to 10(-16) M. Hypothetic mechanisms of these phenomena are discussed.

Animals↗
PubMed2003

Non-oncologic applications of radiolabeled peptides in nuclear medicine.

Radiolabeled peptides have been investigated for diagnostic imaging in a variety of non-oncologic diseases. For imaging thromboembolic disease, peptides which bind to various components of thrombi have been tested. For targeting the fibrin component of thrombi, peptide analogues of fibrin or fragments of fibronectin which have a distinct binding domain for fibrin have been studied. For targeting activated platelets within thrombi, linear and cyclic peptide antagonists of the glycoprotein IIb/IIIa receptor on platelets have been studied, as well as naturally occurring antagonists of this receptor which are found in venoms. Analogues of laminin and thrombospondin which bind to other receptors on platelets have also been tested. There is an approach which uses a peptide to target thrombin which is sequestered within a fibrin clot. Another area of investigation has been to develop an improved radiopharmaceutical for imaging sites of infection and/or inflammation. Peptides which would bind to leukocytes in vivo, such as antagonists to the tuftsin receptor, chemotactic peptides, interleukin-8, or a platelet factor 4 analogue, have been radiolabeled for this purpose. These agents would enable imaging of both infection and inflammation. Development of a radiopharmaceutical for specifically imaging infection has focused on antimicrobial peptides such as human neutrophil defensin, ubiquicidin, human lactoferrin and alafosfalin, which are expected to bind selectively to microorganisms and not to leukocytes. Radiolabeled peptides are also being explored as agents for assessing unstable atherosclerotic plaque (endothelin), amyloid deposits (amyloid beta peptides), and the consequences of diabetes mellitus (human C-peptide).

Alzheimer Disease↗
PubMed1991

[Use of synthetic carriers and adjuvants for increasing the immunogenicity of a synthetic peptide from the CS-protein of Plasmodium falciparum].

In order to increase immunogenicity of the peptide (NANP)3, we have prepared a large set of fully synthetic constructions based on the peptide, glycopeptide adjuvant GMDP and some synthetic carriers. Immunogenicity of these constructions was tested on mice (line C57B1/6) responding to the peptide polymer (NANP)40 without carrier and on mice (line BALB/c) not responding to this antigen. Immunogenic constructions based on synthetic polytuftsin induced as high titres of anti-(NANP)3 antibodies as the standard conjugate KLH--(NANP)3. The chimeric peptide consisting of (NANP)3 and tuftsin dimer induced anti-(NANP)3 antibodies in both lines of mice as well. The GMDP covalent attachment to the immunogenic constructions increased the antipeptide antibodies titre. The results are discussed in terms of an approach to synthetic vaccines.

Amino Acid Sequence↗
PubMed1986

Immunomodulation by some oligopeptides.

The influence of bradykinin, some of its analogues, substance P and different partial sequences on lymphoid cells was studied under in vitro conditions. The oligopeptides bradykinin and substance P were found to be able to induce the secretion of charge-changing and chemokinetic lymphokines in very low concentrations. In each case, bell-shaped dose-response curves were registered in a concentration range from 10(-12) to 10(-6) M. An analysis of the lymphokine patterns suggests that T cells are the producer cells of charge-changing lymphokines. Comparing the structure-activity relationships of the peptides, the amino acid sequence Arg-Pro at the N-terminal region of bradykinin and substance P or Pro-Arg at the C-terminal part of tuftsin and rigin appear to be responsible for the lymphokine secretion.

Adjuvants, Immunologic↗
PubMed1986

Chemotaxis of large granular lymphocytes.

The hypothesis that large granular lymphocytes (LGL) are capable of directed locomotion (chemotaxis) was tested. A population of LGL isolated from discontinuous Percoll gradients migrated along concentration gradients of N-formyl-methionyl-leucyl-phenylalanine (f-MLP), casein, and C5a, well known chemoattractants for polymorphonuclear leukocytes and monocytes, as well as interferon-beta and colony-stimulating factor. Interleukin 2, tuftsin, platelet-derived growth factor, and fibronectin were inactive. Migratory responses were greater in Percoll fractions with the highest lytic activity and HNK-1+ cells. The chemotactic response to f-MLP, casein, and C5a was always greater when the chemoattractant was present in greater concentration in the lower compartment of the Boyden chamber. Optimum chemotaxis was observed after a 1 hr incubation that made use of 12 micron nitrocellulose filters. LGL exhibited a high degree of nondirected locomotion when allowed to migrate for longer periods (greater than 2 hr), and when cultured in vitro for 24 to 72 hr in the presence or absence of IL 2 containing phytohemagluttinin-conditioned medium. The chemotactic LGL was HNK-1+, OKT11+ or HNK-1+, OKT11- on the basis of monoclonal antibody and complement depletion. They did not bear either T cell or monocyte cell surface markers, exhibiting an OKT3-, OKT4-, OKT8-, OKM1-, and MO2- phenotype, and did not form E rosettes at 29 degrees C, which is characteristic of lytic NK cells in contrast to T cells. Furthermore, a rat LGL leukemia (RNK) exhibited a chemotactic response to both f-MLP and casein. LGL chemotaxis to f-MLP could be inhibited in a dose-dependent manner by the inactive structural analog CBZ-phe-met, and the RNK tumor line specifically bound f-ML[3H]P, suggesting that LGL bear receptors for the chemotactic peptide.

Animals↗
PubMed1987

[The effect of splenectomy in immature mice].

Overwhelming postsplenectomy infection in childhood has been investigated extensively, both clinically and experimentally. The immunological change after splenectomy in immature mice is reported in this paper. The studies were carried out in 3-week-old immature mice and in 10-week-old mature mice groups. The immunological change after splenectomy in immature mice were as follows. One week after splenectomy, cellular immunity decreased, so that the phagocytosis of macrophages and the function of granulocytes were decreased. Three weeks after splenectomy, cellular immunity and the function of granulocytes improved but the phagocytosis of macrophages was still at the low level. Cellular immunity, the function of granulocytes and the phagocytosis of macrophages were within normal range 5 weeks after splenectomy. Several previous reports have demonstrated a lower IgM concentration. Tuftsin deficiency and activity decreased in opsonization after splenectomy. We showed the more primitive responses than cellular immunity are also depressed in this paper, that is, splenectomy in immature mice resulted in decrease in the phagocytosis of macrophages and dysfunction of granulocytes.

Animals↗
PubMed1983

Induction of tissue transglutaminase in mouse peritoneal macrophages.

Tissue transglutaminase accumulates rapidly and to very high levels (1-2% of cellular protein) in mouse peritoneal macrophages cultured in mouse serum. The induction is due to accelerated synthesis of the enzyme (150-fold increase) that occurs within 90 min of exposure of the cells to a heat-labile constituent of serum or plasma. The induction is reversible and is not reproduced by known activators of macrophage function such as lipopolysaccharide, muramyl dipeptide, and tuftsin. In animals, elevated levels of tissue transglutaminase are also found in inflammatory macrophages elicited by thioglycolate broth.

Acyltransferases↗
PubMed1983

In vivo antineoplastic activity of various biological response modifiers for tumors of the ovary and breast.

Fourteen pharmacologic agents reported to have biological activities which are directly or indirectly antineoplastic, were assayed for their ability to inhibit the growth of a mouse neoplasia (M5076) and a rat mammary adenocarcinoma (13762) implanted beneath the renal capsule of the host. Ascorbic acid, cimetidine hydrochloride. Corynebacterium parvum, dimethylsulfoxide, naloxone hydrochloride, indomethacin, muramyl-dipeptide, Protein A from Staphylococcus aureus, theophylline, tilorone (analog R11, 877DA), tuftsin diacetate and sodium ibuprofen were completely inactive as antineoplastic agents for these 2 tumors. In fact, theophylline and dimethylsulfoxide seemed to enhance the formation of 13762 metastases. Blue tongue virus and polyinocinic-polycytidylic acid were marginally effective antineoplastic agents for 13762. Polyinocinic-polycytidylic acid was an excellent antineoplastic agent for M5076; this agent not only prevented the growth of M5076, it was oncolytic.

Adjuvants, Immunologic↗
PubMed1984

[Protocols for the treatment of leukemia and lymphoma: toward escalation or toward reduction of degree?].

The present AML protocol which only applies one anthracycline associated with arabinosyl-cytosine gives a first remission plateau of 65% and a 75% survival plateau at five years. Contrary to other teams, we do not apply the allogenic bone marrow graft at the first remission but at the second one. The new protocol comprises application of two anthracyclines, adriamycin and aclacinomycin, a possible autologous bone marrow graft at first remission upon reinforcement, a combination of methotrexate and thioguanine as maintenance chemotherapy and immunotherapy with bestatine. The two protocols respectively applied to the ALL good prognosis and reserved prognosis, give 85% global survival. The autologous bone marrow graft is added at first remission to B or T forms or voluminous CALLA + types. The advantage of CNS radiotherapy is compared with its disadvantages. Bestatine is employed in immunotherapy. The immunoprevention protocol applied to CML blastic crisis (vaccination with a pool of CB blasts) from the second year has prolonged survival of patients suffering from this affection and also treated by splenectomy and hydroxyurea. Allogeneic or autologous bone marrow graft is added to the protocol. The same protocol is applied to not very aggressive LLC and LNH (lymphocytic and centrofollicular with small cleaved nucleus cells) and includes maximum remission induced by chemotherapy followed by immunotherapy (by thymuline and then, if immunity disorders are not corrected, by zinc, then bestatine and finally tuftsin). A similar sequence was applied to the myeloma, comprising MLP-PDN-CPM chemotherapy to induce remission, combination of MLP-PDN and CPM and, if there is resistance, CLB, 6-TG, PDN and TNP. Interferon is appropriate with certain cytopenic forms. A protocol comprising VCR, ADM, PDN, CPM and TNP is applied to centrofollicular NHL with small non cleaved nucleus cells or large cells. As Hoerni and Jones have obtained significant benefits with BCG, its terminal application is compared with that of bestatine. Finally a less mutagenic protocol than MOPP and/or ABVD is proposed for Hodgkin's disease. In this protocol, two cycles alternate, and they combine: a) firstly VCR, PDN, THP-ADM and VPS, and b) secondly VLB, DXM, ACM and TNP with alternatively BLM and PPM between the cycles. This chemotherapy is followed by the same immunorestoration protocol as that applied to LLC and myeloma.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1982

[Should splenic tissue be re-implanted after splenectomy due to birth trauma?].

Splenectomy results in loss of about 1/4 of the reticulo-endothelial system and 1/3 of the lymphatic tissue. Reduced phagocytosis and "clearing" capacity are reflected in the appearance of Howell Jolly bodies, thrombocytosis and decreased circulating immune-complexes. Reduction of IgM and compensatory increase of IgG and IgA levels further indicate immunological impairment. Transitory reduction of complement activity and the number of T-lymphocytes in the first weeks post-splenectomy constitute a significant limitation of immunological function and are accompanied by low serum tuftsin levels. These factors help explain the increased susceptibility to overwhelming infection seen in splenectomized patients. The lethality rate due to sepsis has been reported to be as high as 50%. Patients with hematological disorders, with systemic malignancies and children under 4 years of age who undergo splenectomy because of abdominal trauma are at especially high risk. The most common infectious agents are Haemophilus influenzae and Pneumococcus. The present report describes 2 infants who underwent splenectomy for the treatment of splenic rupture due to birth trauma. In one case, splenic tissue was homogenized and re-implanted; in the second case, splenectomy was followed by penicillin prophylaxis. The clinical course in the latter patient was complicated by Candida meningitis.

Bacterial Infections↗
PubMed1981

Inhibition of C1-mediated immune hemolysis by monomeric and dimeric peptides from the second constant domain of human immunoglobulin G.

Activation of the classical complement cascade by immunoglobulin G involves binding of the first complement component (C1) to a multivalent antigen-IgG complex. Binding occurs by interaction of a site on the surface of the C gamma 2 domain of IgG with a globular head of the C1q subcomponent of C1. Previously we found that the synthetic decapeptide consisting of residues 281-290 from the second constant domain of the gamma-chain of the human IgG1 protein Eu inhibited the binding of human C1 to sensitized erythrocytes. The present study describes inhibition of monomeric and dimeric peptides containing residues 289-292 or 282-292: (formula: see text). On a molar basis, monomeric peptide 282-292 is just as active an inhibitor of C1 binding as peptide 281-290, whereas monomeric peptide 289-292 (tuftsin) is 4 times less active. Peptides 282-292 and 289-292 were each cross-linked at the amino terminus through terephthaloyl-bis(iminodiacetic acid) (Tid). Each dimeric peptide is twice as active on a molar basis as the corresponding monomeric peptide. Dimeric peptide Tid(282-292)2 is just as active on a molar basis as the monomeric 7S form of human IgG1 and 60% as active as the Fc fragment of IgG in inhibiting the binding of human C1 to sensitized erythrocytes. These results suggest that the positively charged residues His-285, Lys-288, Lys-290, and Arg-292, which are located on the outer surface of the C gamma 2 domain, may be involved in the C1q-binding site of human IgG.

Animals↗
PubMed1980

Microoorganisms labeled with 14C for measurement of phagocytosis.

An isotopic method for determination of phagocytic activity is presented. The method of labeling of Staphylococcus aureus 519 with 14C is described. Effects of various parameters (e.g. time of incubation, serum dilution, number of phagocytes and bacteria used in the test on phagocytosis were studied. The effect of tuftsin and its lysine analogue on phagocytes is also described.

Animals↗
PubMed1994

Protective effects of pidotimod against experimental bacterial infections in mice.

Pidotimod ((R)-3-[(S)-(5-oxo-2-pyrrolidinyl) carbonyl]-thiazolidine-4-carboxylic acid, PGT/1A, CAS 121808-62-6) protected mice against experimental bacterial infections in different experimental models. In all tests the drug's effect was measured as protection from death. The activity of pidotimod was evident and statistically significant after 5 administrations before the bacterial challenges. Pidotimod was active against many bacterial species infections, its active dosages ranging from 0.01 to 100 mg/kg i.p. x 5 times. Pidotimod showed against some bacterial infections a protection similar or better than those of bestatin, N-acetylmuramyl-L-Ala-D-isoGlu-OH and tuftsin. It showed high protection against bacterial infections in cyclophosphamide-immunodepressed mice. Finally, pidotimod showed an additive or synergic activity in combination with beta-lactam antibiotics (cefotaxime, ampicillin) against bacterial infections in mice.

Adjuvants, Immunologic↗
PubMed1992

Neurons in the cockroach nervous system reacting with antisera to the neuropeptide leucokinin I.

Antisera were raised against the myotropic neuropeptide leucokinin I, originally isolated from head extracts of the cockroach Leucophaea maderae. Processes of leucokinin I immunoreactive (LKIR) neurons were distributed throughout the nervous system, but immunoreactive cell bodies were not found in all neuromeres. In the brain, about 160 LKIR cell bodies were distributed in the protocerebrum and optic lobes (no LKIR cell bodies were found in the deuto- and tritocerebrum). In the ventral ganglia, LKIR cell bodies were seen distributed as follows: eight (weakly immunoreactive) in the subesophageal ganglion; about six larger and bilateral clusters of 5 smaller in each of the three thoracic ganglia, and in each of the abdominal ganglia, two pairs of strongly immunoreactive cell bodies were resolved. Many of the LKIR neurons could be described in detail. In the optic lobes, immunoreactive neurons innervate the medulla and accessory medulla. In the brain, three pairs of bilateral LKIR neurons supply branches to distinct sets of nonglomerular neuropil, and two pairs of descending neurons connect the posterior protocerebrum to the antennal lobes and all the ventral ganglia. Other brain neurons innervate the central body, tritocerebrum, and nonglomerular neuropil in protocerebrum. LKIR neurons of the median and lateral neurosecretory cell groups send axons to the corpora cardiaca, frontal ganglion, and tritocerebrum. In the muscle layer of the foregut (crop), bi- and multipolar LKIR neurons with axons running to the retrocerebral complex were resolved. The LKIR neurons in the abdominal ganglia form efferent axons supplying the lateral cardiac nerves, spiracles, and the segmental perivisceral organs. The distribution of immunoreactivity indicates roles for leucokinins as neuromodulators or neurotransmitters in central interneurons arborizing in different portions of the brain, visual system, and ventral ganglia. Also, a function in circuits regulating feeding can be presumed. Furthermore, a role in regulation of heart and possibly respiration can be suggested, and probably leucokinins are released from corpora cardiaca as neurohormones. Leucokinins were isolated by their myotropic action on the Leucophaea hindgut, but no innervation of this portion of the gut could be demonstrated. The distribution of leucokinin immunoreactivity was compared to immunolabeling with antisera against vertebrate tachykinins and lysine vasopressin.

Animals↗
PubMed2007

Long range behavior of high-rank topological multipole moments.

The construction of a high-rank multipolar force field (for peptides) is a complex task, leading to several intermediate questions in need of a clear answer. Here we focus on the convergence of the (electrostatic) multipolar expansion at medium and long range. Using molecular electron densities, quantum chemical topology (QCT) defines the atoms as finite volumes, each endowed with multipole moments. The terms in the multipole expansion are grouped according to powers of the internuclear distance, R(-L). Given two atom types at a given distance, we determine which rank (L) is necessary for the electrostatic energy to converge to the exact interaction energy within a certain error. With this information, the rank of the expansion for each interaction can be adapted to the required accuracy and the available computing power.

Carbon Monoxide↗
PubMed2004

Synthesis and structural characterization of bioactive peptide conjugates using thioether linkage approaches.

Applications of cysteine-insertion and thioether linkage approaches to the preparation of a number of bioactive peptide conjugates are reported. Peptides containing epitopes from (i) herpes simplex virus type 1 glycoprotein D, (ii) a specific N-terminal beta-amyloid epitope recognized by therapeutically active antibodies, and (iii) a GnRH-III peptide from sea lamprey with antitumour activity, were elongated with Cys residues and attached to a chloroacetylated tetratuftsin derivative carrier via a thioether linkage either directly, or by insertion of a spacer. The structures and molecular homogeneity of all the peptide conjugates were ascertained by HPLC, MALDI and electrospray mass spectrometry. The use of a spacer such as an oligoglycine or GFLG-tetrapeptide gave an increased yield in the conjugation reaction and enhanced reaction rates. In the formation of cysteinyl-thioether linkages, it was found that the position of flanking Cys residues markedly influenced the conjugation reaction and the formation of intermolecular epitope disulfide-dimers. C-terminal Cys residues gave thioether conjugates with significantly diminished epitope-dimerization, while Cys at the N-terminal caused rapid disulfide-dimerization, thereby preventing efficient conjugation.

Acetates↗
PubMed2006

Synthesis of oligotuftsin-based branched oligopeptide conjugates for chemotactic drug targeting.

The synthesis and chemotactic properties of a new class of branched oligopeptide-based conjugates are described. Tetratuftsin derivatives containing chemotactic formyl tripeptides (For-MLF, For-NleLF or For-MMM) in branches were prepared by stepwise solid-phase peptide synthesis. The influence of the composition and ionic charge of the carrier-branched oligopeptide on the chemotactic behaviour of the conjugate was studied in Tetrahymena pyriformis. Conjugates with methotrexate (Mtx) as a drug component was also prepared. For this, a GFLGC spacer, cleavable by cathepsin B, was used. The spacer with N-terminal methotrexate was coupled to the chloroacetylated chemotactic carrier molecule by thioether bond formation. The chemotactic activity and cytotoxity of Mtx conjugates were also studied.

Amino Acid Sequence↗