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A Arena

Publications and source records attributed to A Arena.

At least 37 records · Page 2Linked to original sources
PubMed1997

In vitro effects of lithium chloride on TNF alpha and IL-6 production by monocytes from breast cancer patients.

It is well known that lithium chloride (LiCl) is able to trigger human monocytes to release tumor necrosis factor alpha (TNF alpha). In this study we have evaluated the in vitro effect of LiCl on TNF alpha and interleukin-6 (IL-6) release by monocytes from patients affected by non-metastatic (BCa/M0) and metastatic breast cancer (BCa/M1), preincubated with autologous serum (sPt). Our data demonstrate that monocytes from cancer patients (BCa) treated with LiCl released lower amounts of TNF alpha compared to those from healthy donors (HD). Preincubation in autologous serum (sPt) impaired TNF alpha production by monocytes from BCa with LiCl. On the contrary, our data indicate that IL-6 production by monocytes treated was not impaired. Moreover, the results obtained from the same cells, preincubated in sPt and treated with LiCl, indicate that serum factors may synergize with LiCl treatment in releasing IL-6.

Aged↗
PubMed1997

Productive HHV-6 infection in differentiated U937 cells: role of TNF alpha in regulation of HHV-6.

This study characterizes the effect of differentiation on the resistance of the human monocytic cell line U937 to human herpes virus type 6 (HHV-6). The use of monocytic cell line has the advantage of avoiding genetic variations among different donors. The HHV-6 infection was compared in undifferentiated U937 cells and U937 cells differentiated with a combination of vitamin D3 and retinoic acid. Undifferentiated U937 cells were highly resistant to HHV-6 infection. Differentiation of U937 cells was accompanied by an increase in permissiveness for HHV-6 demonstrated in terms of extracellular virus production and viral antigen positive immunofluorescent cells. Tumor necrosis factor alpha (TNF alpha) appears to be an essential mediator during the first line defences of the host against viruses, even though its role during viral infection remains controversial. For this reason we examined the behaviour of TNF alpha in differentiated U937 upon HHV-6 infection. No basal production of TNF alpha was found in culture supernatants, while HHV-6 infection up-regulated TNF alpha release. The addition of human recombinant-TNF alpha to HHV-6 infected cells induced a marked cytotoxic effect accompanied by an increased release of extracellular virus, whereas it did not affect viral replication, as shown by the unmodified percentage of antigen positive cells. In conclusion, TNF alpha acts as a soluble mediator of cytotoxicity against HHV-6 infected U937 cells, but it fails to induce an antiviral state.

Antibodies, Blocking↗
PubMed1997

Production of TNF alpha and interleukin 6 by differentiated U937 cells infected with Leishmania major.

Several cytokines play a crucial role in the defense of the host against protozoa belonging to the genus Leishmania. However, the role of tumor necrosis factor alpha (TNF alpha) and interleukin 6 (IL-6) in human leishmaniasis is still controversial. The aim of this work was to study, in an "in vitro" model, the interactions of human phagocytes with L. major. The U937 human monocytic cell line, differentiated with phorbol myristate acetate (PMA) or a combination of 1 alpha,25 dihydroxyvitamin D3 (VD) and retinoic acid (RA), was used in all the experiments. The rate of infection, as well as the production of TNF alpha and IL-6 by cells upon infection with promastigotes, were studied. It was found that, depending on the agent used for differentiation, U937 cells produced different patterns of cytokines. PMA differentiated cells produced significantly more TNF alpha, but less IL-6 than cells differentiated with VD-RA. No direct relationship was found between the ability of differentiated U937 cells to release TNF alpha or IL-6 and their leishmanicidal activity.

Animals↗
PubMed1997

Treatment of acute respiratory failure secondary to pulmonary oedema with bi-level positive airway pressure by nasal mask.

We report the successful outcome of first-line intervention of noninvasive positive pressure ventilation (NPPV) in four patients, three of whom had hypercapnic acute respiratory failure (ARF) and one hypoxaemic ARF, secondary to pulmonary oedema. The clinical condition showed rapid improvement and the NPPV, performed together with aggressive medical treatment, was effective in decreasing the respiratory frequency, and in correcting gas exchange abnormalities within the first 3 h. The average duration of nasal mask ventilation was 11 h (range 6-15 h). The patients were weaned, following ARF, by removing the ventilator whenever inspiratory positive airway pressure (IPAP) was 5 cmH2O. NPPV was applied, by nasal mask, using a bi-level positive airway pressure (BiPAP) delivering pressure support ventilation (PSV). We conclude that application of noninvasive positive pressure ventilation may be effective in correcting gas exchange abnormalities, in relieving respiratory distress and, perhaps, in avoiding endotracheal intubation in selected patients with acute respiratory failure secondary to reversible medical condition such as pulmonary oedema.

Aged↗
PubMed1996

Immunobiological activities of mould products: functional impairment of human monocytes exposed to aflatoxin B1.

In order to elucidate the effects upon the human immune system of aflatoxin B1 produced by the food-contaminating mould Aspergillus flavus, phagocytosis, microbicidal activity, superoxide production and intrinsic antiviral activity were studied in monocytes exposed to aflatoxin B1 for different times at concentrations ranging from 0.1 to 1 pg/ml. Phagocytosis and microbicidal activity were significantly impaired (p < 0.05) by aflatoxin B1 at doses as low as 0.1 pg/ml. However, pretreatment of monocytes with aflatoxin B1 did not modify intrinsic antiviral activity or superoxide production. These results confirmed data obtained from animals fed with mycotoxin-contaminated foods. The potential danger to human health of exposure to mycotoxins demonstrates the necessity for careful microbiological control of food.

Aflatoxin B1↗
PubMed1996

CA125 in culture medium of preimplantation embryo.

The first stage of the implantation is the adhesion of the embryonic pole of the blastocyst to the decidua. Such a phenomenon has been demonstrated to be dependent on the presence of glycoproteic compounds, produced partly by the decidua and partly by the embryo. CA125 is an antigenic determinant associated to a glycoprotein expressed by various embryonic tissues. The objective of our research has been to measure the production of CA125 by the embryo in the initial phase of its development. Patients were recruited from our in vitro fertilization program. The culture medium used for the oocytes and for the embryos was collected and CA125 levels were measured. The results indicate that there is not a statistically significative difference between the values of CA125 measured in the mediums where a pronucleus or an embryo was present and the negative controls. From our data, therefore, it can be concluded that CA125 expression begins later in the human embryonic development than 8-cells-stage embryo.

Blastocyst↗
PubMed1996

Halogenated isoniazid derivatives VI. Evaluation of anti-HSV-1 and anti-HIV-1 in vitro activities of fluorinated analogues.

The synthesis and evaluation of antiviral in vitro activity are reported of some 2'-(1-arylethyl)isonicotinohydrazides (5a-d) and N-(1-arylethyl)isonicotinohydrazonic acids (6a-d), obtained by reducing fluorinated acetophenone isonicotinoylhydrazones (2a-d) with sodium cyanoborohydride. These INH analogues, along with other ones previously prepared, i.e. benzaldehyde isonicotinoylhydrazones 1, 4-aryl-1-methoxyl-1-(4-pyridyl)-2,3-diaza-1,3-butadienes 3 and 5-aryl-4-methyl-2-(4-pyridyl)-delta 2-1,3,4-oxadiazolines 4, were assayed for anti-HSV-1 activity on the monoblastoid cell line U937. Only some compounds (1b, 1d, 4d and 4e) displayed a moderate antiherpetic activity. In addition, the reduced compounds 5 and 6, submitted to the anti-HIV-1 screening, did not display significant effects in reducing virus-induced cytopathogenicity. The cytotoxicity of all compounds has been assayed on Vero cells and some considerations in correlation with structure are discussed.

Animals↗
PubMed1996

Role of IFN gamma on TNF alpha, IL-1 beta and IL-6 release during HHV-6 infection.

The release of monokines such as Tumor Necrosis Factor a (TNF alpha), Interleukin-1 beta (IL-1 beta) and Interleukin-6 (IL-6) by activated monocytes/macrophages is an important step in the immune as well as in the inflammatory response. In this study the production of TNF alpha, IL-1 beta and IL-6 by human monocytes (HM) and peripheral blood mononuclear cells (PBMC) was evaluated after HHV-6 infection. Our results demonstrate that HHV-6 can selectively regulate monokine synthesis, in a time-dependent manner. Moreover, we observed a different response closely related to the cellular population (HM or PBMC) examined. The hypothesis we evaluated was that IFN gamma is an important factor triggering the activation of HHV-6 infected human monocytes, to release monokines.

Adjuvants, Immunologic↗
PubMed1996

[Changes in myocardial Tc-99m-sestamibi uptake in asynergic territories during low-dose echo-dobutamine test].

BACKGROUND: Recent data suggest that contractile reserve in dysfunctional but viable myocardium during low-dose dobutamine infusion might be elicited not only by a direct inotropic stimulation but also by an increase in coronary blood flow. Aim of the study was to evaluate the effects of low-dose dobutamine on myocardial perfusion and function in asynergic but viable myocardium. METHODS: Nineteen patients with coronary artery disease and severe regional dysfunction were studied. Both regional ventricular function and myocardial perfusion were assessed at rest (PRE), during low-dose dobutamine (DOB) and, in twelve patients, after revascularization (POST). Regional ventricular function was evaluated with two-dimensional echocardiography using a score index ranging from 1 to 4. Myocardial perfusion was studied using Tc-99m-sestamibi Single Photon Emission Tomography (SPET); uptake defects were graded from 0 (normal) to 4 (absent uptake). For both evaluations the left ventricle was divided in 16 segments and two vascular territories were considered. RESULTS: Low-dose dobutamine elicited contractile reserve in 12 of 24 asynergic vascular territories (DOB+). Compared with PRE scintigraphy, DOB SPET showed perfusion improvement in 10/12 DOB+ and in 3/12 DOB- asynergic territories (p = 0.006). Mean uptake score decrease significantly in DOB+ (from PRE SPET 21.0 +/- 7.2 to DOB SPET 17.6 +/- 7.1; p = 0.0005) but not in DOB- (from SPET PRE 19.0 +/- 5.3 to SPET DOB 19.5 +/- 6.8, p = NS) abnormal territories. Fourteen asynergic territories underwent revascularization. Among them, 9 showed functional recovery after intervention (viable myocardium) and 5 showed no changes (fibrotic myocardium). A functional improvement under dobutamine was observed in 7 viable and in 1 fibrotic territories. Conversely, perfusion improved under dobutamine in 8 viable and in one fibrotic territory. After revascularization the perfusion defect score decreased significantly in viable territories (from PRE SPET 22.1 +/- 7.9 to POST SPET 13.3 +/- 6.6; p = 0.00001) but not in fibrotic regions (from PRE SPET 17.8 +/- 6.0 to POST SPET 15.6 +/- 4.9). CONCLUSIONS: In asynergic myocardium contractile reserve elicited by low-dose dobutamine is associated in most cases with an improvement in Tc-99m-sestamibi uptake. This suggests a possible link between increased blood flow and functional improvement during dobutamine in viable myocardium.

Aged↗
PubMed1992

Acute intermittent porphyria. A perplexing case.

We report the case of a 58-year-old woman affected by polyneuropathy, vegetative disturbances and abdominal pain. A provisional diagnosis of acute intermittent porphyria was made and was confirmed by the increased levels of urinary delta-aminolevulinic acid (ALA) and porphobilinogen (PBG).

Acute Disease↗
PubMed1992

Generation of superoxide anion and candidacidal activity by lipopolysaccharide-treated macrophages from patients affected by neoplasia.

Macrophages, derived from in vitro cultured monocytes from both healthy donors and patients affected by metastatic breast cancer, treated or not with Escherichia coli lipopolysaccharide (LPS), were tested for phagocytosis and intracellular killing of Candida albicans and superoxide anion release. We found a marked impairment in intracellular killing closely linked to the lack of superoxide production in macrophages from patients affected by neoplasia treated or not with LPS. On the other hand, the LPS treatment significantly enhanced the phagocytic activity of all the macrophage populations tested, except for phagocytes obtained from patients affected by neoplasia and differentiated in autologous serum.

Adult↗
PubMed1992

Fluorocontaining D-cycloserines. Synthesis and in vitro evaluation of antimicrobial and antiviral activities.

Some fluoroacylderivatives at the side chain NH2 of D-cycloserine were synthesized and evaluated in vitro for antimicrobial activity against bacteria and tubercular or non-tubercular mycobacteria. Against the used Gram-positive and Gram-negative strains only trifluoroacetamide 1 exhibited comparable MIC values and lower MBC values than those of parent antibiotic. Other fluoroacycloserines, inactive at all on these bacteria, were found to inhibit the growth of mycobacteria when tested in liquid media. The in vitro anti-Herpex Simplex virus type-2 (HSV-2) activity was also investigated on HEp-2 and Vero cells. The obtained results demonstrated an antiviral activity of the compounds 1 and 3 when tested on Vero cell-lines, whereas the same cycloserine is inactive.

Animals↗
PubMed1991

Platelet activating factor involvement in splanchnic artery occlusion shock in rats.

Splanchnic artery occlusion shock was induced in anesthetized rats by clamping the splanchnic arteries for 45 min. The survival rate, plasma levels of thromboxane B2 (TxB2) and 6-keto-PGF1 alpha, serum and peritoneal levels of macrophage tumor necrosis factor (TNF alpha), the phagocytotic and killing activity of peritoneal macrophages and white blood cells count were evaluated. Shocked rats died within 2 h, while all sham-shocked rats survived more than 6 h. Plasma TxB2 and 6-keto-PGF1 alpha levels were increased in rats subjected to splanchnic artery occlusion shock compared to the levels in sham-shocked animals. Serum and peritoneal macrophage TNF alpha levels were undetectable in sham-shocked rats, whereas shocked rats exhibited increased levels of TNF alpha. Moreover, splanchnic artery occlusion shock reduced peritoneal macrophage phagocytotic and killing activity, and also produced severe leukopenia. A specific receptor antagonist of platelet activating factor (PAF), L-652, 731 (an i.v. bolus of 3.2 mg/kg 2 min after removal of the clamps followed, 5 min thereafter, by a continuous infusion of 0.16 mg/kg per min for 30 min) significantly increased the survival rate, lowered plasma TxB2 levels and reduced both serum and macrophage TNF alpha levels in shocked rats. In addition, L-652,731 completely restored macrophage phagocytosis, partially improved macrophage killing and significantly inhibited leukopenia. Finally, the administration of L-652,731 had beneficial effects on the cardiovascular changes induced by splanchnic artery occlusion shock. These findings are consistent with the involvement of PAF in splanchnic artery occlusion shock and indicate that PAF produces shock through direct and indirect (TxB2-mediated and TNF alpha-mediated) actions.

6-Ketoprostaglandin F1 alpha↗
PubMed1991

Serum TNF alpha in mouse typhoid and enhancement of a Salmonella infection by anti-TNF alpha antibodies.

Tumour necrosis factor alpha (TNF alpha) was detected by the L929 cell assay in the sera of mice 1 h after large i.v. inocula of virulent Salmonella typhimurium C5. TNF alpha was not detectable in sera from innately susceptible BALB/c mice during the course of a lethal infection commencing from a low inoculum, or from resistant A/J mice during the course of a lethal or sublethal infection, but only 1 h after i.v. challenge with large numbers of organisms. Administration of a single dose of rabbit polyclonal anti-TNF alpha antiserum on day 1 had no effect on the early course of a lethal infection in A/J mice. However, the same treatment exacerbated a sublethal infection in A/J mice. Anti-TNF alpha treatment did not accelerate the early bacterial net growth rate in the RES. Instead, the cfu count in treated mice continued to increase past the point at which the host response suppressed a further increase in bacterial numbers (the plateau phase) in normal controls. A second dose of anti-TNF alpha antiserum on day 4 together with a higher but still sublethal challenge caused a lethal infection in A/J mice. The results indicate that TNF alpha is important in mediating the plateau phase in a salmonella infection, and its effect may be local.

Animals↗
PubMed1991

Modulation of the intrinsic antiviral activity by Escherichia coli endotoxin in macrophages from patients with neoplasia.

Macrophages from patients with breast cancer showed an impairment of their antiviral activity. The capability to hinder herpes simplex virus type 2 replication of macrophages from healthy donors and from patients with breast cancer was compared to the in-vitro treatment with Escherichia coli lipopolysaccharide (LPS). The LPS showed a dose-dependent effect on the different macrophage populations studied. Nevertheless, macrophages from healthy donors appeared to be more sensitive to LPS in comparison with macrophages from the patients under our observation. On these cells LPS treatment was not able to modify the antiviral property, when these macrophages were differentiated in autologous serum.

Analysis of Variance↗
PubMed1990

Heterotopic gray matter. Report of a case.

We report the case of a 40 year old man who presented a tonic-clonic seizure. The CT scan and MRI revealed heterotopic gray matter in the right frontoparietal cortex.

Adult↗
PubMed1990

Role of exogenous interferons on intrinsic antiviral activity of macrophages from patients affected by neoplasia.

Macrophages derived from in vitro cultured monocytes were infected with herpes simplex virus type 2. A marked impairment in the intrinsic antiviral activity was found in macrophages obtained from patients with breast cancer or melanoma. Moreover, the antiviral activity of macrophages from healthy donors, differentiated in serum from patients with neoplasia, was also impaired. The aim of this work was the evaluation of alpha, beta, gamma exogenous interferon in restoring the intrinsic antiviral activity of macrophages from patients affected by breast cancer or melanoma under different conditions. Pretreatment of macrophages with alpha, beta interferons, but not gamma interferon, restored their impaired intrinsic antiviral activity.

Aged↗