Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Tuftsin”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 325 records · Page 18Linked to original sources
PubMed1989

Neurotensin regulation of macrophage colony-stimulating factor-stimulated in vitro myelopoiesis.

Neurotensin, at less than or equal to 10(-9) M, in the presence of an optimal concentration of macrophage CSF (CSF-1), stimulated a dose-dependent enhancement of colony formation by murine marrow-derived mononuclear phagocyte progenitor cells. The additional colonies arose from the cell cycle and Ia Ag-positive subpopulation previously identified as two-signal-dependent progenitors. Two-signal colony formation diminished when the peptide was added at concentrations greater than 10(-9) M. Neurotensin binds specifically to two distinct receptors, a high affinity receptor (KD approximately 10(-9) M) and a lower affinity (KD approximately 10(-7) M) receptor identified as the tuftsin receptor. Rat liver ferritin and an inhibitory tuftsin analog. (ALA1)-tuftsin, which inhibit two-signal colony formation stimulated by tuftsin and tuftsin-like peptides in combination with CSF-1, did not inhibit colony formation stimulated by CSF-1 and 10(-9) M neurotensin. Both inhibitors, however, reversed the loss of two-signal colony growth in the presence of higher neurotensin concentrations. Neurotensin fragment 1-6, unlike ferritin and (ALA1)-tuftsin, inhibited two-signal colony formation stimulated by 10(-9) M neurotensin. However, like ferritin and (ALA1)-tuftsin, fragment 1-6 permitted full expression of two-signal colony formation in the presence of CSF-1 and 10(-7) M neurotensin. The data indicated that occupancy of both receptors at neurotensin concentrations greater than 10(-9) M might be responsible for the diminished progenitor response. The data further support a potential role for neurotensin as an inflammatory mediator. In addition to direct effects on mature phagocytic leukocytes, neurotensin, at least in vitro can influence the production of new mononuclear phagocytes.

Animals↗
PubMed1981

Rigin, another phagocytosis-stimulating tetrapeptide isolated from human IgG. Confirmations of a hypothesis.

Structure-function and conformational studies of the molecule of phagocytosis-stimulating tetrapeptide tuftsin permitted the conclusion that among products resulting from splitting of H-chain of IgG Human EU by trypsin, besides tuftsin (sequence 289-292), tuftsin-like tetrapeptide Gly-Gln-Pro-Arg may be also present; theoretical conformational analysis shows a considerable similarity of spatial arrangement of this tetrapeptide and tuftsin which testifies in favour of potential tuftsin-like activity of the tetrapeptide. Gly-Gln-Pro-Arg was synthesized and its phagocytosis stimulating activity was found equal to that of tuftsin.

Amino Acid Sequence↗
PubMed2002

The value of partial splenic autotransplantation in patients with portal hypertension: a prospective randomized study.

HYPOTHESIS: Splenic autotransplantation plays a role in preserving immune function of the spleen in patients with portal hypertension and liver cirrhosis. DESIGN: Prospective randomized study. SETTING: University hospital. PATIENTS: Twenty patients (19 men and 1 woman; aged 33-80 years) suffering from portal hypertension and liver cirrhosis were randomly allocated into 2 groups. Each group consisted of 10 patients. INTERVENTIONS: All patients underwent modified Sugiura operation. In the control group, splenectomy was performed, while partial splenic autotransplantation into the retroperitoneal space was additionally completed in the splenic autotransplantation group. MAIN OUTCOME MEASURES: Serum tuftsin and IgM were measured preoperatively and 2 months after surgery. Dynamic scintigraphy with technetium Tc 99m-labeled heat-damaged erythrocytes was performed at 2-month intervals during the 8-month follow-up. RESULTS: There was no statistical difference in the mortality of the groups. The preoperative levels of serum tuftsin and IgM showed no statistical difference between groups. However, although these measures had decreased remarkably in the control group 2 months after operation (P<.001 for serum tuftsin; P =.04 for serum IgM), they remained stable in the splenic autotransplantation group (P =.25 for serum tuftsin; P =.12 for serum IgM). Four patients within the splenic autotransplantation group showed positive scanning of the transplanted splenic fragment during follow-up, whereas there was no positive scanning in the control group. CONCLUSION: Our results suggest that partial splenic autotransplantation can preserve immune function of the spleen, as measured by serum levels of tuftsin and IgM, in patients with portal hypertension and liver cirrhosis.

Adult↗
PubMed1981

Postsplenectomy splenic activity.

Evidence of recurring activity of splenic tissue was investigated in patients who had undergone splenectomies. Methods included technetium 99m sulfur colloid scan, serum tuftsin assay, serum immunoglobulin concentration, blood cell counts, and search for Howell-Jolly bodies. Positive scans were observed together with normal levels of tuftsin in 54% of the patients. In 46% of the patients, no splenic activity was detected by scanning and low levels of tuftsin were noticed. The difference in tuftsin levels between the two groups was statistically significant. Howell-Jolly bodies and decreased serum levels of IgM featured all patients. The possible application of combined splenic scan and tuftsin assessment for screening recurring splenic activity in the postsplenectomy population at great risk is suggested.

Adolescent↗
PubMed1987

Proteolysis of human C-reactive protein produces peptides with potent immunomodulating activity.

We have studied the ability of human C-reactive protein to modulate the immune response in vitro. Whereas native C-reactive protein did not induce phagocytic leukocytes to chemotax or to produce superoxide, treatment of purified C-reactive protein with human neutrophil-derived acid proteases produced substances with potent effects on leukocyte function. Close examination of the primary structure of human C-reactive protein revealed three regions evenly distributed throughout the protein each of which contain peptide sequences closely resembling the amino acid sequence of the immunomodulator peptide tuftsin, Thr-Lys-Pro-Arg. We have synthesized the three peptides which include Thr-Lys-Pro-Leu ([Leu4]tuftsin), Gly-Lys-Pro-Arg ([Gly1]tuftsin), and Thr-Lys-Pro-Gln ([Gln4]tuftsin) and assayed them for biological activity. The three synthetic peptides were found to stimulate phagocytic leukocytes to chemotax, produce superoxide, and induce mononuclear cells to produce interleukin 1 in vitro at concentrations similar to those concentrations required for tuftsin to induce these phenomena. These results support a potentially important role for C-reactive protein as a possible immunomodulator during inflammation.

Amino Acid Sequence↗
PubMed1995

[The mechanism for splenic promoting effects on liver cirrhosis].

The model of liver cirrhosis was induced by CCl4 and alcohol in rats, which were subjected to splenectomy or given Tuftsin. The isolated and purified liver parenchymal, Kupffer and Ito cells were cultured with CCl4 and splenic conditional fluid or Tuftsin. The RNA isolated from the liver tissues of cirrhosis animals were hybridized with five kinds of cDNA probes. In this study we explored the mechanism of spleen's promoting effects on the liver cirrhosis formation at the whole body, cellular and molecular levels. The result showed that in cirrhosis model, the levels of IL1, IL6 and TNF alpha in serum of rats in imitative splenectomy or Tuftsin group were significantly increased compared to those in splenectomy group (P < 0.05). Cell culture showed that if medium contained CCl4 and splenic conditional fluid or Tuftsin, its cells can secrete more fibronectin, laminin and collagen I than those cultured in medium only contained CCl4 (P < 0.05). Slot blot hybridization showed that the RNA isolated from liver of rats in imitative splenectomy or Tuftsin group hybridized with probes of TNF alpha, IL1 beta, TGF beta and Collagen I had a more high density picture of X-ray than that isolated from liver of rats in the splenectomy group. Should be it a complex process for spleen to promote liver cirrhosis formation, in which the TGF beta gene expression enhancement may be the key of splenic effects on liver fibrosis.

Animals↗
PubMed2001

Autotransplant of spleen tissue in children with schistosomiasis: evaluation of splenic function after splenosis.

Autotransplantation of spleen tissue has been done, in the past ten years, in children with schistosomiasis mansoni with bleeding varices. The purposes of this investigation were: (1) to study the morphology and function of the remnant spleen tissue; (2) to quantify the production of tuftsin; and (3) to assess the immune response to pneumococcal vaccine of these patients. Twenty three children, who underwent splenectomy and autologous implantation of spleen tissue into the greater omentum were included in this investigation. The average postoperative follow-up is five years. Splenosis was proved by colloid liver-spleen scans. Search for Howell-Jolly bodies assessed the filtration function. Tuftsin and the titer of pneumococcal antibodies were quantified by ELISA. Splenosis was evident in all children; however, it was insufficient in two. Howell-Jolly bodies were found only in these two patients. The mean tuftsin serum concentration (335.0 +/- 29.8 ng/ml) was inside the normal range. The immune response to pneumococcal vaccination was adequate in 15 patients; intermediate in four; and inadequate in four. From the results the following conclusions can be drawn: splenosis was efficient in maintaining the filtration splenic function in more than 90% and produced tuftsin inside the range of normality. It also provided the immunologic splenic response to pneumococcal vaccination in 65% of the patients of this series.

Adolescent↗
PubMed1987

[Taftsin correction of pharmacologically induced behavioral disorders in white rats].

Tetrapeptide tuftsin in doses adapted to its physiological blood concentrations partially normalized locomotor activity and orientation behaviour of rats altered by drugs affecting aminergic brain systems. At the same time tuftsin had no effect when applied after the treatment by dopaminergic drugs (DTC, haloperidol, apomorphine). It can be concluded that the central effect observed in the first minutes after tuftsin administration is mediated through dopaminergic system. Elimination of some drug-induced behavioural disturbances by tuftsin opens new prospects for its therapeutic application.

Animals↗
PubMed1985

Inhibition by various peptides of the activation of C1, the first component of complement, and the interaction of C gamma 2 domain of IgG with C1q.

Three groups of peptides were synthesized, each of which was proposed to be a part of the C1q binding sites of the C gamma 2 domain of IgG. They were: Trp(277)-Tyr-Val-Asp-Gly (WYVDG), Thr(289)-Lys-Pro-Arg (tuftsin) and Gly(316)-Lys-Glu-Tyr-Lys (GKEYK) or portions of these peptides. Assays included CH50, consumption of serum complement induced by heat-aggregated IgG, C1 hemolysis and an enzyme immunoassay that directly measures interaction between C1q and IgG. Peptides near Gly(316) such as GKEY, GKE or EYK inhibited CH50 and heat-aggregated IgG-induced consumption of serum complement. WYVDG also inhibited CH50, with 50% inhibition at 2.05 mM, which was more than the concentrations of peptides near Gly(316) at 50% inhibition. Tuftsin was only slightly inhibitory in both systems. Results of C1 hemolysis indicated that dipeptides composed of two aromatic amino acids, especially Trp-Tyr, were more inhibitory than dipeptides of which one residue was an aromatic amino acid. Peptides such as EYK, GKEY or GKE were very inhibitory, and tuftsin was far less inhibitory than these peptides in C1 hemolysis. Results of enzyme immunoassay also showed that dipeptides composed of two aromatic amino acids were more inhibitory than dipeptides of which one residue was aromatic amino acid. WYVDG was most inhibitory in enzyme immunoassay, but tuftsin, EYK, GKEY GKE and KE were less effective.

Binding Sites↗
PubMed1983

Evaluation of factors affecting mortality rate after sepsis in a murine cecal ligation and puncture model.

A murine model was used to test the effects of various therapeutic modalities on the rate of death following intra-abdominal sepsis as produced by cecal ligation and puncture (CLP). There were no deaths among sham-operated control mice after ether anesthesia, whereas CLP produced a mortality rate of 100% by 24 hours. When CLP was followed at 16 hours by excision of the cecum and saline peritoneal lavage (CLPE), the mortality rate was 20% at 24 hours and 60% at 72 hours. The therapeutic modalities consisted of gentamicin (1.5 mg/kg) alone or in combination with methylprednisolone (50 mg/kg) or tuftsin (1 mg/kg) administered before CLP and at 16 and 24 hours after CLP. Separate groups of animals also received only methylprednisolone or tuftsin, a tetrapeptide produced by the spleen. Compared with the mortality rate in the CLPE group, mortality at 24 and 72 hours was decreased for gentamicin alone (0% and 10%, respectively), tuftsin alone (10%, 40%), or the two in combination (0%, 20%). As compared with CLPE, methylprednisolone led to increased mortality rates at 24 and 72 hours (70%, 80%). The data (significant at P less than 0.01, X2 analysis) suggest that gentamicin and tuftsin may improve the rate of early survival after intra-abdominal sepsis in this Model. Steroids do not seem to be beneficial and may, in fact, be harmful.

Anesthesia↗