The effect of ascorbic acid on production of human interferon and the antiviral activity in vitro

The effects of ascorbic acid on interferon production and on the antiviral effect of interferon in cultures of human cells were investigated. Ascorbic acid enhanced the interferon levels produced by human embryo skin and human embryo lung fibroblasts, induced by Newcastle disease virus and by polyinosinic-polycytidylic acid. The same concentrations of ascorbic acid had no effect on interferon production in two lymphoblastoid cell lines induced by Sendai virus. Leucocyte interferon assayed in lung fibroblasts titrated 0.2-0.3 log10 units higher in the presence of 5 mug ascorbic acid than in the absence of the latter.     

Mechanism of the inhibitory effect of melatonin on tumor necrosis factor production in vivo and in vitro

Melatonin is an antioxidant. Since other antioxidants inhibit the production of tumor necrosis factor (TNF) induced by lipopolysaccharide, we investigated its effect on TNF production in vivo and in vitro and on lethality associated with endotoxic shock. Administration of melatonin to mice (5 mg/kg, s.c., 30 min before or simultaneously with lipopolysaccharide) inhibited serum TNF levels by 50-80% and improved survival of mice treated with a lethal dose of lipopolysaccharide. By studying other, structurally related, indolamines (N-acetyl-5-hydroxytryptamine, 5-methoxytryptamine and 5-hydroxytryptamine) we found a good correlation between antioxidant activity (for which the 5-methoxy group is essential) and the inhibition of TNF production in vivo and in vitro in mononuclear cells. Melatonin did not increase serum corticosterone and did not modify the elevation of serum corticosterone levels by lipopolysaccharide or by interleukin-1. Furthermore, it exerted its inhibitory effect in adrenalectomized or hypophysectomized mice also, indicating that its effect is independent of the hypothalamus-pituitary-adrenal axis.     

In vivo and in vitro studies of the inhibitory effect of propofol on human platelet aggregation

BACKGROUND: The inhibitory effects of propofol on platelet aggregation are controversial because the fat emulsion used as the solvent for propofol may affect platelet function. The effects of propofol on platelet intracellular calcium ion concentration and on aggregation were investigated. METHODS: Platelet aggregation was measured in 10 patients who received an intravenous infusion of propofol. Intralipos, the propofol solvent, was infused in 10 healthy volunteers and platelet aggregation were measured. The in vitro effects of propofol and Intralipos on platelets were also investigated. The inhibitory effects of various concentrations of propofol were studied. The effects of propofol on the changes in intracellular calcium level using a fluorescent dye, fura-2, were also observed. Template bleeding time was measured to determine the effect of propofol in clinical use. RESULTS: Platelet aggregation was significantly inhibited by infusion of propofol, although bleeding time was not prolonged. Intralipos did not inhibit platelets either in vivo or in vitro. Propofol significantly inhibited platelet aggregation in vitro and at 5.81 +/- 2.73 microg/ml but not at 2.08 +/- 1.14 microg/ml. The increase of intracellular calcium concentration was inhibited both in influx and discharge of calcium. CONCLUSIONS: Propofol inhibited platelet aggregation both in vivo and in vitro. Inhibition of platelet aggregation appeared to be caused by propofol itself and not by the fat emulsion. This inhibitory effect was also supported by the suppressed influx and discharge of calcium. No change in the bleeding time suggests that this inhibitory effect does not impair hemostasis clinically.     

Interleukin-18 enhances lipopolysaccharide-induced interferon-gamma production in human whole blood cultures

Interleukin-18 (IL-18) is a newly described cytokine, formerly called interferon-gamma (IFN-gamma)-inducing factor. In a simple 24-h human whole blood culture, IFN-gamma was produced by the combination of lipopolysaccharide (LPS) plus IL-18. To liberate cytokines in the leukocyte and red cell compartments, the detergent Triton X-100 was added to the entire blood culture. The combination of low concentrations of LPS plus IL-18 induced a 3- to 5-fold greater production of IFN-gamma than did either stimulant alone. Tumor necrosis factor-alpha (TNF-alpha), IL-6, and IL-8 were also produced. The presence of IL-10 completely suppressed the production of IFN-gamma and reduced that of TNF-alpha, IL-6, and IL-8. Thus, IFN-gamma, TNF-alpha, IL-8, and IL-6 are produced in a single whole blood culture, making correlations in the synthesis of a T helper type 1 cytokine and proinflammatory cytokines with disease activity possible in a single culture.     

Effects of ketotifen on human lymphocytes in vitro and in vivo

The effects of the antiasthmatic drug ketotifen (CAS 34580-13-7) on human mononuclear leukocytes were studied in vitro and in vivo. In vitro ketotifen concentration-dependently inhibited mitogen-stimulated lymphocyte proliferation. High ketotifen concentrations also inhibited T-lymphocyte mitogen- and adenosine triphosphate stimulated increases in intracellular Ca2+ in lymphocytes and the U937 human monocyte precursor cell line, respectively; this involved inhibition of both Ca2+ influx and intracellular mobilization. In in vivo experiments, treatment of healthy volunteers with 1 mg ketotifen b.i.d. for 7 d did not alter the number or subset composition of circulating lymphocytes. Moreover, the mitogen-stimulated in vitro proliferation of lymphocytes obtained before and after ketotifen treatment in vivo was similar. It is concluded that high ketotifen concentrations can inhibit the activation of resting lymphocytes in vitro but standard ketotifen treatment does not notably affect the number of function of circulating lymphocytes in vivo.     

The effect of prednisolone on canine neutrophil function: in vivo and in vitro studies

It is generally accepted that growth of muscle tissue depends in part on biomechanical factors. However, the precise relationships that govern mechanically induced growth are not known. This paper uses available data to propose a set of biomechanical growth laws for striated and smooth muscle. For striated muscle fibers, transverse and longitudinal growth are hypothesized to depend on the active and passive fiber stress, respectively. For smooth muscle fibers in arteries, transverse growth is assumed to depend on the fiber stress (active behavior is ignored), with longitudinal growth depending on both fiber stress and the shear stress on the endothelium due to blood flow. In both types of muscle, the rate of growth is assumed to depend linearly on the stresses. Relatively simple models for skeletal muscle, the heart, and arteries are used to show that the proposed growth laws can predict many of the known characteristics of muscle growth during development and following load perturbations in the mature animal.     

Lead differentially modifies cytokine production in vitro and in vivo

An imbalance between helper T cell type 1 (Th1) and helper T cell type 2 (Th2) activation can result in immunodysregulations leading to impaired cell-mediated immunity with an increased incidence of infectious disease or cancer and/or aberrant humoral immunity that may culminate with an autoimmune disease. Mercury, a heavy-metal toxicant, is known to induce renal autoimmunity characterized by a predominant Th2 response. Lead, another metal toxicant, causes enhanced B cell activities and impairs host resistance to several bacterial and viral infections. In addition, Pb was reported to enhance Th2 proliferation and inhibit Th1 proliferation. The differential effects of Pb on Th subset activation have been further investigated. In vitro IL-4 production by a Th2 clone was significantly increased by the addition of PbCl2, whereas IFN gamma production by a Th1 clone was decreased by the addition of PbCl2. When BALB/c mice were subcutaneously exposed to PbCl2, ex vivo Il-4 production by anti-CD3-stimulated splenic T cells was enhanced, but IFN gamma production was inhibited. Additionally, the plasma IL-4 and IgE levels of Pb-exposed mice were increased, and the plasma IFN gamma levels were significantly lowered in the absence of any additional exogenous antigen. In vitro, ex vivo, and in vivo treatment with HgCl2 produced similar findings. This study is the first report of the preferential activation of a Th2 response by Pb in vivo and suggests that PB, like Hg, may induce autoimmune responses by upsetting the balance between Th1- and Th2-like cells, which could enhance production of antibodies to self antigens.     

Zinc aspartate in vivo and in vitro modulation of reactive oxygen species production by human neutrophils and monocytes

In April 1991, an oral health situation analysis team comprising oral health professionals from the Alaska Area Native Health Service, the World Health Organization, and the Moscow Medical Stomatological Institute visited the Magadan region of the Soviet Far East at the request of the Ministries of Health of both the Russian Republic and the then-Soviet Union. As few oral health data had been available specific to the Magadan region, the purpose of the trip was to gather data concerning oral diseases epidemiology, demography, and health systems of the communities of Magadan, Seymchan, and Provideniya as the basis for recommendations and plan development. The data were collected using standard WHO methodology. The analysis team examined children in the age cohorts of 3-5, 6-7, 12, and 15 years. In addition, adults aged 35-44 and 65-74 years were examined in Magadan and Seymchan. Both caries and periodontal rates are high, with a rate of 4.3 DMFT among 12-year-olds in the total region, but up to 5.4 DMFT in one location. Specific findings and recommendations have been forwarded to local community and health officials. The project is ongoing, and plans are underway to provide continuing assistance in designing and implementing an effective program for the prevention and treatment of oral diseases.     

The effect of Shakuyaku-kanzo-to on prostaglandin production in human uterine myometrium

Thymosin alpha 1 (T alpha 1) is an immune modulatory peptide which has been evaluated in a variety of clinical trials. Although no in vivo adverse effects, including enhancement of tumor growth, have been noted, in vitro studies suggesting a role for T alpha 1 in cell growth have been reported. The studies presented in this report evaluated both exogenously added T alpha 1 and endogenously expressed T alpha 1 as factors which could either promote growth of tumor cells or induce transformation. No effect of exogenous T alpha 1 on cell growth was found. NIH-3T3 cells transfected with cDNA for the precursor ProThymosin alpha (Pro T alpha) expressed elevated levels of authentic T alpha 1 but did not demonstrate either enhanced proliferation in liquid culture or transformation as defined by the loss of contact inhibition or anchorage independent growth in soft agar. Thus these studies argue against the hypothesis that T alpha 1 is either an intracellular or extracellular growth promoter.     

The effect of simian immunodeficiency virus infection in vitro and in vivo on the cytokine production of isolated microglia and peripheral macrophages from rhesus monkey

Microglia are the major target for human immunodeficiency virus (HIV) infection within the central nervous system. Because only a few cells are productively infected, it has been suggested that an aberrant cytokine production by this cell population may be an indirect mechanism leading to the development of neurological disorders in HIV-infected patients. Therefore we decided to study the secretion pattern of several interleukins (IL) by microglial cells and peripheral blood macrophages isolated from uninfected and simian immunodeficiency virus (SIV)-infected Rhesus monkeys. We found that uninfected, unstimulated primate microglia produce more IL-6 and less TNF alpha than peripheral blood macrophages, but generate comparable levels of IL-1 beta and IL-8. After infection with SIV in vitro, synthesis of all cytokines tested is increased compared to uninfected cultures and to peripheral blood macrophages. Microglia isolated from infected animals produce more IL-8 and TNF alpha than the uninfected cultures and display a strongly increased capacity to secrete TNF alpha upon stimulation with lipopolysaccharide. In addition, production of IL-6 by in vivo-infected microglia increases with time in culture to very high levels despite the fact that only a few cells contained replicating virus. These findings clearly show that the cytokine production of microglia is impaired after SIV infection both in vitro and in vivo and that a low level of viral replication is sufficient for these alterations to occur. In conclusion, the results of this study further support a possible role of cytokines in the pathogenesis of neuro-AIDS.     

The effect of octreotide on wound healing: an in vitro and in vivo experimental study

OBJECTIVE: To investigate the effect of octreotide on wound healing. DESIGN: Experimental studies in vitro and in rats. SETTING: Teaching hospital, Israel. MATERIAL: Cultured human diploid fetal fibroblasts, and 36 male Wistar rats. INTERVENTIONS: Octreotide was added to cultures of fibroblasts in doses of 2, 10, 30, 60 and 120 ng/ml and fibroblasts were counted after 2, 4, and 6 days. Intestinal anastomoses were made in 36 rats. Rats in the octreotide group (n = 18) were given subcutaneous injections of 0.25 microg/kg twice daily and 6 rats were killed at 3, 7, and 14 days. The control group were given injections of saline. Anastomotic bursting pressures and hydroxyproline content were measured at each of the three times. MAIN OUTCOME MEASURES: Fibroblast counts, anastomotic bursting pressures, and hydroxyproline concentrations. RESULTS: Octreotide did not inhibit fibroblast proliferation in any of the doses at any of the time periods. The anastomotic bursting pressure was slightly higher in the octreotide group at each of the time points, but not significantly so, and there was no difference in hydroxyproline content between the octreotide and control groups. Octreotide did not inhibit wound healing either in vitro or in vivo.     

Interleukin-17 and interferon-gamma synergize in the enhancement of proinflammatory cytokine production by human keratinocytes

OBJECTIVES: To investigate the correlation of epidermal growth factor receptor (EGFR) expression and its ligands EGF and transforming growth factor-alpha (TGF-alpha) with disease outcome in a cohort of patients with superficial bladder cancer. METHODS: Tumor samples of 21 patients with transitional cell carcinoma of the bladder were analyzed by immunohistochemistry for expression of EGFR, EGF, and TGF-alpha. Disease-related events were recorded during a routine clinical follow-up and analyzed for possible correlation with the expression status of the above-mentioned proteins. RESULTS: All Stage pT1 transitional cell carcinomas expressed EGFR, and 10 of 21 (48%) tumors showed focal areas of strong EGF and/or TGF-alpha expression. Of these, 80% with EGF positivity (8 of 10) had recurrences, whereas only 9% of patients without EGF staining (1 of 11) did so. The same pattern was observed with TGF-alpha. A strong association was confirmed between EGF/TGF-alpha positivity and tumor recurrence (P <0.005). We also found that EGF and TGF-alpha were expressed in stroma and/or around the vessels of tumor tissue in 48% and 38% of the tumors, respectively. No association was found between the recurrence rate/vascular invasion and the stromal/vascular wall expression of the growth factors. CONCLUSIONS: Expression of EGF and TGF-alpha is correlated with tumor recurrence. Also, there is the ability of vessel walls to express EGF and TGF-alpha in superficial bladder cancer. Further clarification of the impact of this expression on angioinvasion of tumor cells may be helpful in understanding the nature of local invasion and metastasis.     

The effect of in vitro human immunodeficiency virus infection on dendritic-cell differentiation and function

CD1a+ dendritic cells (DC) differentiate from a major population of nonadherent CD13(hi)lin- cells that appear when human cord blood CD34+ hematopoietic progenitor cells are cultured with stem-cell factor, granulocyte/macrophage (MA) colony-stimulating factor, and tumor necrosis factor-alpha (TNF-alpha) for 5 days. CD13hilin- cells, which also comprise MA and granulocyte precursors, are CD4+ and can thus be targets of human immunodeficiency virus (HIV). Low replication was noted when these day 5 cells were infected with lymphotropic HIV-1LA1 (p24: < or = 4 ng/mL on day 8 postinfection [PI]), while high virus production occurred with MA-tropic HIV-1Ba-L, HIV-1Ada, or HIV-1-m-n. (p24: 50 to > or = 1,000 ng/mL). Strong cytopathicity (CPE) was then observed in nonadherent cells as in adherent MA. However, FACS analysis on day 7 PI showed that HIV did not affect differentiation of DC that survived CPE: apart from CD4 downmodulation related to HIV production, overall expression of CD40, CD80, and CD86 costimulatory molecules, and of HLA-DR, was unchanged relative to controls. At that time, the capacity of DC from HIV-infected cultures to stimulate the mixed leukocyte reaction was only altered less than 10-fold. Immunocytochemistry on day 7 PI showed that most HIV-infected cells were included in syncytia that were stained by anti-CD1a, anti-S100, and anti-CD14 antibodies, indicating that syncytia consisted of DC and cells of the MA lineage. Polymerase chain reaction analysis of FACS-sorted CD1a+ cells confirmed that they harbored then HIV DNA. Viral DNA was also detected in CD1a+ DC from noninfected cultures that had been exposed to HIV only after sorting. Therefore, we examined whether in infected cultures DC precursors were infected at the onset or if virus spread later from other infected cells to differentiated DC. This was answered by showing that, 24 hours postexposure to HIV, viral DNA was preferentially detected in day 5 sorted CD13hilin- versus CD13hilin- cells, and that it was found in the CD1a+ progeny of CD13(hi)lin- cells 48 hours later. In addition, HIV replication did not affect myeloid clonogenic progenitors in day 0 to day 7 PI cultures, although viral DNA was detected in colony-forming unit-granulocyte/macrophage (CFU-GM)/CFU-M colonies derived from day 3 and 7 PI cultures. Thus, precursors of DC and their progeny are susceptible to HIV in vitro, but, apart from CPE, the effect of virus production on DC differentiation or function is limited.     

In vitro and in vivo effect of glucocorticoids on IgE and IgG subclass secretion

Hydrocortisone (HC) as well as its synthetic derivatives have been shown to strongly enhance interleukin-4 (IL-4)-induced in vitro IgE synthesis. To investigate possible effects on IgG subclasses, peripheral blood mononuclear cells (PBMC) were incubated with different glucocorticosteroids in the absence or presence of IL-4. The glucocorticoids alone led to a strongly enhanced secretion of IgG1, IgG2 and IgG3, but not IgG4. The addition of IL-4 induced marked increases in IgG1 and IgG4, no changes in IgG3, but a consistent decrease in IgG2 synthesis. In order to find out whether these profound in vitro effects of corticosteroids are also reflected by changes in antibody serum levels during steroid treatment, 10 healthy volunteers took 25 mg prednisone for 7 consecutive days. We could not observe any significant changes of IgE or IgG subclass serum levels during or after this period. However, cell cultures performed after the glucocorticoid treatment revealed a marked decrease in the ability to produce IgG4 and a significantly lower potential to produce IgE in response to IL-4 alone or IL-4 and HC. We conclude that, although strongly implicated by the in vitro results, glucocorticosteroid treatment does not result in an increased allergy risk.     

The effect of dexamethasone on CRH and prostanoid production from human term placenta

The human placenta at term produces large quantities of corticotropin releasing hormone (CRH) and prostanoids. These hormones play an important role in the maintenance of pregnancy, and the initiation and progress of labor; yet little is known of factors affecting their regulation and the interrelationship of CRH and prostanoid production. In these studies we have investigated the effect of dexamethasone on the production of CRH and prostanoids from fresh human term placental tissues. The basal release of prostaglandin E2 (PGE2), prostaglandin F2 alpha (PGF2 alpha), thromboxane B2 (TxB2) and 6-keto-prostaglandin F1 alpha (6-keto-PGF1 alpha) from human term placental explants increased from the fifth hour in culture, while the release of 13,14-dihydro-15-keto-PGF2 alpha (PGFM) was not significantly changed during this period. The addition of dexamethasone (10(-8) M) to the perifusing medium resulted in a rapid and dramatic inhibition of PGE2, PGF2 alpha, PGFM, TxB2 and 6-keto-PGF1 alpha release. On the other hand, CRH release was not significantly changed throughout the seven hours of incubation with dexamethasone. These data demonstrate that glucocorticoids at physiologic concentrations can inhibit human term placental prostanoid production, and thus glucocorticoid production may play an important role in the physiological regulation of placental prostanoid production in the human placenta. However, dexamethasone did not alter CRH release, demonstrating that the inhibition of placental prostanoids by dexamethasone is not a CRH mediated event.     

Phagocytosis-enhancing effect of lactoferrin on bovine peripheral blood monocytes in vitro and in vivo

The effect of lactoferrin (LF) on in vitro and in vivo phagocytic ability of bovine blood monocytes was studied. It was demonstrated that bovine LF enhanced in vitro phagocytosis of bacteria and ovine erythrocyte-antibody complexes and increased intracellular killing of Staphylococcus albus. Monocytes of colostrum deprived calves, which were intravenously injected with LF, also exhibited elevated phagocytic properties.     

The effect of heparin on the interaction of factor VIII and human platelets in vitro

Heparin was found to inhibit the interaction between human factor VIII and platelets. This was noted in two different systems, namely, platelet aggregation induced by neuraminidase-treated human cryoprecipitate and platelet aggregation induced by ristocetin-human factor VIII complex. Heparin appeared to have an inhibitory effect on the above systems similar to that reported on bovine factor VIII-induced platelet aggregation.     

The effect of platelets on invasiveness and protease production of human mammary tumor cells

Interaction of tumor cells with platelets facilitates metastasis of tumor cells. It has been proposed that platelets protect tumor cells against the host's immune defense and enhance tumor-cell extravasation. In the present work we show that platelets increase the invasiveness of 3 mammalian cell lines (MCF-7, ZR-51 and MDA-MB231) through extracellular matrix, and propose this as an additional mechanism by which platelets facilitate metastasis. Since gelatinase and urokinase have both been implicated in degradation of the extracellular matrix and cell migration, and therefore in tumor invasion, we have also analyzed whether the interaction of platelets with tumor cells can modify the secretion of these proteases by tumor cells. MDA-MB231, which was the most invasive cell line among the 3 tested and was the most potent in inducing platelet aggregation, secreted the highest level of urokinase and was the only one in which gelatinase was detected. While platelets had no significant effect on the urokinase activity expressed by these cells, they induced in MDA-MB231 an important increase in the secretion of gelatinase, which can be reproduced by both platelet membrane and platelet releasate of activated platelets. This increase in gelatinase could be responsible, at least in part, for the increased invasiveness of these cells, since added TIMP-1 significantly reduced the number of cells which traversed matrigel.     

The effect of basic fibroblast growth factor on coronary vascular tone in experimental hypercholesterolemia in vivo and in vitro

Twenty-three patients with symptomatic giant hemangioma of the liver were treated by surgery between 1979 and 1996 at the department of General Surgery, Faculty of Medicine, University of Cukurova. Twenty-three enucleations were performed in 21 patients, left lateral segmentectomy in one patient and enucleation plus left lobectomy in one patient. The tumors were enucleated along the interface between the hemangioma and normal liver tissue. The diameters of the tumors ranged from 5 x 5 to 25 x 15 cm. The mean blood loss for enucleations was 525 ml (range 500-1000 ml). There was no mortality and no postoperative bleeding. Three patients had postoperative complications. Enucleation is the best surgical technique for symptomatic giant hemangioma of the liver. It may be performed with no mortality, low morbidity and the preservation of all normal liver parenchyma.