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At least 397 records · Page 22Linked to original sources
PubMed1989

[Effect of splenectomy on phagocytic function of leucocytes].

By means of whole blood chemiluminescence, phagocytic function of leucocytes (PFL) and the opsonic activity of plasma (OAP) were examined in 27 patients to observe the effect of splenectomy on phagocytic function of leucocytes. It was found that, the PFL of splenectomized patients was significantly lower than that of healthy persons and patients with cholecystectomy. It was then believed that the impaired immunological function against infection in splenectomized patients was related to the abnormal PFL resulting from the disappearance of tuftsin in the circulation, an important leucocytic activator produced only in the spleen. It was showed in this paper that the whole blood chemiluminescence is a simple, rapid and useful method in detecting PFL and OAP.

Adolescent↗
PubMed1989

[Macrophage activation by synthetic peptides. I. Kinetic changes in the transport of fluorescein anions across the plasma membrane of macrophages].

As shown by cytofluorimetric technique, fluorescein anions formed in macrophages due to hydrolysis of fluorescein diacetate (FDA) release into the extracellular medium through the probenecid-inhibitable transport system of organic acids. Technical procedures have been elaborated to record separately the process of FDA hydrolysis characterising the activity of intracellular esterases, and the fluorescein anion transport representing secretion of organic acids by macrophages. It has been established that the tetrapeptide tuftsin stimulates the cell esterase activity without affecting the rate of fluorescein efflux. The peptide KPR (Lys-Pro-Arg) decreases both the esterase activity and the fluorescein anion efflux.

Amino Acid Sequence↗
PubMed1987

[Neuroimmunoregulatory properties of short protein fragments in rats exposed to immobilization stress].

The influence of short protein fragments on immobilization stress-induced alterations in neuroendocrine and immune systems (catecholamine content in the striatum, hypothalamus and adrenals, serum corticosterone concentration, specific antibody producing activity) was investigated. Immunoglobulin G fragments--tuftsin, rigin, polar amino acid set--polarin and thymus hormone fragment--thymopoetin, as well as substance P (as reference drug) were administered intraperitoneally at doses of 100 and 500 micrograms/kg 30 min before exposure to stress. Rigin and thymopentin showed high stress-protective activity. It is suggested that similar protein fragments, being endogenously formed, may play a regulating role in neuroimmunological homeostasis during exposure to stress.

Adjuvants, Immunologic↗
PubMed1988

[Characteristics of the action of psychostimulants on learning and memory in rats].

The effects of intraperitoneal injections of psychostimulant drugs: centrophenoxine (50 mg/kg) and peptide analog of tuftsin TP-1 (300 micrograms/kg) on the processes of elaboration and retention of conditioned reflex have been experimentally studied. The animals were trained with food reward in 30 trials per day. Psychostimulant drugs or saline were injected after the 10th trial. The elaboration of conditioned reflex was continued 30 min later. The retention was tested 24 h, 7 and 30 days later. It was established that both drugs induce an increase in memory traces stability during 30 days. These findings provide direct evidence that psychostimulant drugs, centrophenoxine and peptide substance TP-1, when injected during consolidation phase can enhance memory storage processes.

Animals↗
PubMed1985

An in vivo assay for chemoattractant activity.

We have devised an implantable device for the study of leukocyte chemoattraction. The device consists of a 0.25-mm thick patch of Dacron fabric coupled to a disc of ethylene vinyl acetate copolymer. Such polymers can release biologically active molecules at a constant rate for at least 18 days. Attracted cells invade and are trapped within the Dacron fabric. Upon removal from the host, the fabric patches are sectioned and stained to reveal the distribution of attracted cells. Distinct patterns of cellular accumulation can be seen for different chemoattractant molecules. These include the attraction of eosinophils by histamine, monocytes by tuftsin, and mast cells by glycyl-histidyl-lysine. Maximal accumulation of specific cell types occurs at postimplantation days 1 to 2 for neutrophils, days 3 to 5 for monocytes, and days 5 to 6 for macrophages and eosinophils. Control polymers fail to cause significant leukocyte accumulation, indicating that neither the polymer nor the Dacron fabric provokes an inflammatory response.

Alprostadil↗
PubMed1988

[Use of fluorescein diacetate for research on macrophage activation].

Kinetic of changes in the fluorescence intensity of macrophages in a medium containing fluorescein diacetate (FDA) has been analysed. It is shown that under certain conditions the intensity of macrophages retains a constant level for rather a long time. The addition of stimulants such as lipopolysaccharide or tuftsin to the incubation medium leads to characteristic changes in the cell fluorescence level related to the increase in the activity of FDA intracellular hydrolyses and fluorescein efflux from macrophages. It is concluded that the kinetic of changes in the macrophages fluorescence intensity in a medium with FDA may serves as a test for detecting early functional changes upon macrophage activation.

Animals↗
PubMed1987

Synthesis of a new carrier for immunization: polytuftsin. Two examples of its use with peptides selected in the hepatitis B surface antigen.

Sequential poly(Arg-Thr-Lys-Pro) consisting mainly of the repeat of tuftsin Thr-Lys-Pro-Arg was synthesized by condensing the p-nitrophenyl ester of Arg(HCl)-Thr-Lys-(2-Cl-Z)-Pro in the presence of HOBt. Two haptenic sequences of the Pre-S region of hepatitis B virus antigen (10-26 and 39-55) were prepared by solid phase and coupled to polytuftsin via glutaraldehyde. The peptides, either free or coupled to polytuftsin, were administrated to mice and the antisera were assayed by ELISA. Coupling the peptides to the polypeptide significantly improved the anti-peptide antibody titer in Freund complete adjuvant or in NaCl 0.9%. Cross-reaction between antibodies induced by the peptides and the native protein was also improved. Polytuftsin alone is very poorly immunogenic.

Animals↗
PubMed1979

Torsion of the spleen in a five-and-a-half-month-old infant.

In this report, we describe torsion of the spleen in a five-and-a-half-month-old infant, thus far the youngest reported patient in the literature. Celiac angiography and tuftsin determination confirmed the clinical impression that the pathology was confined to the spleen. The infant underwent a splenectomy and made an uneventful recovery.

Celiac Artery↗
PubMed1983

Enhancement of the permeability-increasing effect of bradykinin and substance P by a peptide derived from fibrinogen.

Two low molecular weight fibrin(ogen) degradation products, 6A (Ala-Arg-Pro-Ala-Lys) and 6D (Ser-Gln-Leu-Gln-Lys-Val-Pro-Pro-Glu-Trp-Lys) that are known to increase vascular permeability were injected together with bradykinin, substance P, neurotensin, histamine or tuftsin into the dorsal skin of rats. Effects on microvascular permeability were evaluated as leakage of intravenously injected 125I-labelled human serum albumin to tissues. It was found that peptide 6A potentiated the leakage caused by bradykinin and also, to a minor extent, that caused by substance P over a 30 min period, but not of any other substance. Peptide 6D increased bradykinin-induced leakage to a lower degree than did peptide 6A. Thus, it is shown that products resulting from fibrinolysis exert a selective effect upon the action of bradykinin and of substance P.

Animals↗
PubMed1984

[Life-threatening infections after splenectomy--the overwhelming post- splenectomy infection syndrome].

About 2.5% of the patients, on whom splenectomy is done, die later from fulminant bacterial infection. This particular late sequelae usually occurs within 5 years after surgery, however, - especially in adults, - it has been observed also decades after splenectomy. Pneumococci have been identified as infectious agents in about 70% of the cases concerned. This syndrome is caused by deficient clearance of bacteria, which is due to reduced phagocytosis, decreased IgM-production, disturbances of the complement system and lack of tuftsin. Prevention of this syndrome may be achieved by using surgical procedures saving part of the spleen, by appropriate use of antibiotics and by vaccination against pneumococci.

Adult↗
PubMed1981

Preservation of splenic function by autotransplantation of traumatized spleen in man.

Splenectomy is known to increase the risk of overwhelming bacterial infection. Characteristically, there is a decrease in immunoglobulin IgM, properdin, and T-lymphocytes; impaired primary antibody response to antigen challenge; an altered opsonic function; and a tuftsin deficiency. Because the spleen is important in host defense, preservation of traumatized splenic tissue has been advocated. Splenic autotransplantation has been suggested as a method of preserving function, and this concept is supported by experiments in animals. The present study describes autotransplantation of the traumatized spleen in human beings for the preservation of splenic function. Four patients operated on for blunt abdominal trauma required total splenectomy for hemostasis and were deemed suitable candidates for autotransplantation of the splenic tissue. In each, thinly sliced segments of spleen (roughly 20 gm.) were placed in a previously fashioned omental pouch. All patients survived without complications. Postoperative studies included blood and platelet counts, cell morphology, determination of serum immunoglobulin levels, and splenic scans. Four weeks postoperatively, Howell-Jolly bodies and target cells had disappeared from the red cells. Platelet counts returned to normal range. Initially low IgM and C3 complement levels increased to normal. Scans at 8 weeks confirmed the presence of functioning splenic tissue. Autotransplantation of the spleen is a safe method for preserving splenic function when total splenectomy is mandatory for hemostasis.

Adolescent↗
PubMed1978

Microorganisms labeled with 14C for measurement of phagocytosis.

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

Animals↗
PubMed1993

Treatment of the adult retina with microglia-suppressing factors retards axotomy-induced neuronal degradation and enhances axonal regeneration in vivo and in vitro.

To monitor the cascade of events initiated by injury of adult neurons, and to explore whether and how neighboring microglial cells contribute to the degradation of lesioned neurons, axotomy-induced ganglion cell degeneration was investigated in adult rats. Suppression of macrophage and microglia activity during the weeks following transection of the optic nerve was performed with the immunoglobulin-derived tripeptide Thr-Lys-Pro, which is a macrophage inhibitory factor (MIF) and retards the activity of cells of monocytic origin. Single or repeated injection of MIF into the vitreous body during and after transection of the optic nerve resulted in significant retardation of axotomy-induced ganglion cell degradation in the retina as detected by specific labeling with the retrogradely transported fluorescent dye 4Di-10ASP. MIF specifically altered the morphology of labeled microglial cells from a ramified to an oval, less ramified shape, indicating that these cells were targets of its activity. Injection of the tetrapeptide macrophage stimulating factor, also known as tuftsin (Thr-Lys-Pro-Arg), revealed effects opposite to those described for the MIF: it increased the number of labeled microglial cells and enhanced the devastating effects of axotomy on ganglion cells. The viability of rescued ganglion cells in retinas treated with the various drugs was assessed both in vivo and in vitro. (1) Intravitreal injection of MIF to prevent degradation of neurons combined with transplantation of autologous peripheral nerve grafts, which facilitate regrowth of the transected neurites, revealed that significantly more ganglion cells contributed to axonal regeneration (17.1%) than in untreated controls (9.5%). (2) Explantation of retinas that were pretreated with MIF in situ revealed higher incidence of axonal outgrowth in organ cultures than untreated control explants or retinas treated with either the basic fibroblast growth factor or brain-derived neurotrophic factor. The present results demonstrate that axotomy initializes a cascade of microglia-mediated autodestructive retinal responses, which culminate in degradation of "sick," but obviously viable neurons. We postulate that the retinal microglial system has a key role in recognizing and eliminating severed neurons.

Amino Acid Sequence↗
PubMed1995

Allotransplantation of whole spleen in patients with hepatic malignant tumors or hemophilia A. Operative technique and preliminary results.

BACKGROUND: It has been reported that the spleen performs a vital function in the fight against malignant tumors. The spleen is the primary producer of tuftsin, which can directly or indirectly kill tumor cells or inhibit their growth. The spleen is also believed to produce coagulating factor VIII. Therefore, allotransplantation of the spleen can be used in the treatment of patients with malignant tumors and hemophilia A. DESIGN: Heterotopic allotransplantation of whole spleen was performed in six patients with advanced hepatocellular carcinoma and hemophilia A. An adjuvant immunotherapy with interferon alfa was simultaneously administered in the patients with liver cancer. SETTING: Tongji Hospital, Tongji Medical University, Wuhan, China. RESULTS: Among six cases of allografting of whole spleen, five grafts were successful; one failed because of torsion of the splenic hilum. Three patients with hepatocellular carcinoma survived 9, 11, and 5 months after transplantation. Marked shrinkage of hepatic tumors and reduced serum alpha-fetoprotein levels were observed in these patients. On 5-year follow-up, three patients with hemophilia who had undergone splenic allografts were alive, and two had experienced substantial clinical improvement. In these two patients, when the grafts were functioning well and the recipients were free of acute rejection or graft-vs-host reaction, the mean plasma factor VIII activity remained between 30% and 36%, with peak factor VIII activities of 53.7% and 66.6%. We also evaluate operative technique and posttransplantation complications. CONCLUSION: Our results strongly imply that the spleen is one of the primary sites of synthesis of factor VIII and that the spleen has an inherent ability to fight malignant diseases. Allografting of whole spleen may be a promising technique for the treatment of patients with unresectable hepatocellular carcinoma and severe hemophilia A.

Adult↗
PubMed1988

Macrophage phagocytosis of biodegradable microspheres composed of L-lactic acid/glycolic acid homo- and copolymers.

A variety of biodegradable microspheres were prepared from L-lactic acid, DL-lactic acid, or glycolic acid homopolymers and copolymers of different molecular weights and monomer compositions. Phagocytosis of the microspheres by mouse peritoneal macrophages was studied in cell culture system using scanning electron microscopy as well as light microscopy. The diameter of microspheres prepared was less than 2 microns, regardless of the starting polymers. No dependence of the chemical nature of starting polymers was observed on the extent of phagocytosis of the microspheres by macrophages. Precoating the microspheres with water-soluble macromolecules such as proteins had great influence on phagocytosis by macrophages. It was demonstrated that precoating with bovine serum albumin and non-proteinaceous macromolecules reduced the phagocytosis of microspheres, while bovine gamma-globulin, human fibronectin, bovine tuftsin, and gelatin precoating enhanced the phagocytosis. This trend was not influenced by the presence of serum. Only in the case of gelatin precoating, the phagocytosis was greatly enhanced by the presence of serum as compared to precoating with other proteins. Microscopic observation clearly indicated that the phagocytosed microspheres were gradually degraded in the macrophage interior with the incubation time, leading to release of a fluorescent dye encapsulated in the microspheres. The rate of microsphere degradation in cells could be controlled by changing the molecular weight and the monomer composition of the copolymers comprising the microspheres.

Animals↗
PubMed1984

In vitro generation of hydrogen peroxide and of superoxide anion by bovine polymorphonuclear neutrophilic granulocytes, blood monocytes, and alveolar macrophages.

Studies were conducted to compare the capacity of bovine blood monocytes, polymorphonuclear granulocytes (PMNs), and alveolar macrophages (AMs) to generate hydrogen peroxide and superoxide anion. Following stimulation with opsonized zymosan, bovine PMNs respond with an immediate and vigorous liberation of both oxygen species, generating 4.7 +/- 0.3 nmol H2O2/10(6) cell and 12.3 +/- 1.8 nmol O2-/10(6) cell during the initial 15 min. This is more than twice the amount generated by AMs (1.2 nmol H2O2/10(6) cell; 2.5 and nmol O2-/10(6) cell) and blood monocytes (0.5 nmol H2O2/10(6) cell; 2.1 nmol O2-/10(6) cell) during the same period. However, AMs continue generating H2O2 and O2- at a steady rate for a longer period and consequently produce amounts equal to those of PMNs when measured over a longer time span. Also, AMs can be stimulated with nonopsonized zymosan in contrast to PMNs. However, the AM population appears to comprise at least two subpopulations, which can be clearly distinguished by their capacity for generation of reactive oxygen species, and which correlate with their tendency for adherence to a plastic surface. In contrast to what has been found in other species, the bovine phagocytes were found to lack receptors for tuftsin and formylated oligopeptides, and thus remained unresponsive to these compounds. The in vitro activity of the three cell types was found to be very dependent on culture conditions, such as cell density and an adherent versus suspended state. In addition, a comparison with macrophages and PMNs elicited into the mammary gland suggest that in vivo factors can significantly influence the in vitro activities. The mammary gland cells have lower activity than blood and alveolar cells, even though they have been "primed" by chemotactic factor(s), and this is probably caused by milk components, i.e., the microenvironment. Our observations are discussed with respect to the results obtained from different laboratories, different species, and different cell types; emphasis is placed on the problem of drawing conclusions about in vivo functions of cells from parameters assayed in vitro.

Animals↗
PubMed1993

Therapeutic effects of a synthetic peptide of C-reactive protein in pre-clinical tumor models.

Previous studies have shown that multilamellar vesicles (MLV) or other carriers containing purified human C-reactive protein (CRP) have therapeutic activity in preclinical tumor models. Here we evaluated the therapeutic effects of MLV containing novel synthetic peptides, derived from the structure of CRP, on the extent of (a) established lung metastases of fibrosarcoma T241 in C57Bl/6 mice, (b) survival of C57Bl/6 mice bearing established liver metastases of colon carcinoma MCA-38, and (c) primary tumor growth of Renca renal carcinoma in Balb/c mice. In all cases, a single synthetic CRP peptide, RS-83277, demonstrated significant antitumor effects comparable to that seen with intact CRP. Two other synthetic CRP peptides, RS-83287 and RS-83147, showed no therapeutic activity and were comparable to control MLV containing only buffer. None of the peptides contained sequences homologous with that of the phagocyte stimulant, tuftsin. Activity of MLV-encapsulated RS-83277 was dose-dependent, and a comparable dose of the soluble peptide, given either alone or following injection of buffer-MLV, was ineffective. These results demonstrate immunotherapeutic potential for a novel synthetic peptide derived from CRP, and endogenous acute-phase protein.

Adenocarcinoma↗
PubMed1979

Studies on the activity of phorbol myrystate acetate on the human polymorphonuclear leukocytes.

Phorbol myrystate acetate (PMA) activates nitroblue tetrazolium reduction in human polymorphs. The activation is inhibited by dibutyryl cyclic AMP, theophylline and phenylbutazone, but is not influenced by hydrocortisone in vitro, nor is it inhibited by leukocytes from patients treated with prednisone. Peptide analogues of Tuftsin also had no effect on this stimulatory activity. We conclude that the action of PMA on the nitroblue tetrazolium reduction is mediated through cyclic nucleotides.

Adult↗