Search results for " gamma"

Accumulation of Amphotericin B in Human Macrophages Enhances Activity against Aspergillus fumigatus Conidia: Quantification of Conidial Kill at the S…

1998

ABSTRACT A cytofluorometric assay that allowed assessment of damage to phagocytosed Aspergillus fumigatus conidia at the single-cell level was developed. After ingestion by monocyte-derived macrophages (MDMs), conidia were reisolated by treatment of the cells with streptolysin O, a pore-forming toxin with lytic properties on mammalian cells but not on fungi. The counts obtained by staining of damaged conidia with propidium iodide and quantification by cytofluorometry correlated with colony counts. By the use of this method, we demonstrate that MDMs differentiated in vitro by low-dose granulocyte-macrophage colony-stimulating factor and gamma interferon have only a limited capacity to damage…

In vivo γδ T Cell Priming to Mycobacterial Antigens by Primary Mycobacterium tuberculosis Infection and Exposure to Nonpeptidic Ligands

1999

The recognition of phosphorylated nonpeptidic microbial metabolites by Vγ9Vδ2 T cells does not appear to require the presence of MHC molecules or antigen processing, permitting rapid responses against microbial pathogens. These may constitute an important area of natural anti-infectious immunity. To provide evidence of their involvement in immune reactivities against mycobacteria, we measured the responsiveness of peripheral blood Vγ9Vδ2 T cells in children with primary Mycobacterium tuberculosis (MTB) infections. Peripheral blood mononuclear cells from 22 children with MTB infections and 16 positivity of tuberculin (PPD)-negative healthy children were exposed to nonpeptidic antigens in vit…

Granulysin‐Dependent Killing of Intracellular and ExtracellularMycobacterium tuberculosisby Vγ9/Vδ2 T Lymphocytes

2001

Contribution of Vgamma9/Vdelta2 T lymphocytes to immune protection against Mycobacterium tuberculosis is still a matter of debate. It was reported earlier that Vgamma9/Vdelta2 T lymphocytes kill macrophages harboring live M. tuberculosis through a granule-dependent mechanism that results in killing of intracellular bacilli. This study found that Vgamma9/Vdelta2 T lymphocytes reduce the viability of both extracellular and intracellular M. tuberculosis. Granulysin and perforin, both detected in Vgamma9/Vdelta2 T lymphocytes, play a major role, which indicates that Vgamma9/Vdelta2 T lymphocytes directly contribute to a protective host response against M. tuberculosis infection.

Selective depression of interferon-γ and granulysin production with increase of proliferative response by Vγ9/Vδ2 T cells in children with tuberculos…

2002

Vgamma9/Vdelta2 T cells can contribute to protective immune response against Mycobacterium tuberculosis, although the extent to which and mechanisms by which they could actually protect against human tuberculosis remain unclear. We have previously reported that Vgamma9/Vdelta2 T cells from tuberculin purified protein derivative (PPD)-positive children, either healthy or affected by different clinical forms of tuberculosis, strongly proliferate to different phosphoantigens in vitro, whereas Vgamma9/Vdelta2 T cells from PPD-negative healthy subjects proliferate very poorly. We report here that Vgamma9/Vdelta2 T cells from tuberculous children have an increased proliferative activity, but decr…

Antiproliferative and chemomodulatory effects of interferon-γ on doxorubicin-sensitive and -resistant tumor cell lines

1993

Biological agents might offer various therapeutic opportunities in the treatment of cancer, including a direct and/or host-mediated antiproliferative effect and also the possibility to favorably modulate tumor resistance to antineoplastic drugs. We studied the in vitro antiproliferative effects of interferon (IFN)-gamma on the mouse B16 melanoma and Friend erythroleukemia, and the human K562 erythroleukemia, as doxorubicin (DXR)-sensitive and -resistant (multidrug resistant) variants. These effects were marked in B16 melanoma and rather slight in K562 erythroleukemia, without any difference between the DXR-sensitive and -resistant lines. The chemosensitive variant of Friend erythroleukemia …

Free radical biology of the cardiovascular system

2012

Most cardiovascular diseases (CVDs), as well as age-related cardiovascular alterations, are accompanied by increases in oxidative stress, usually due to increased generation and/or decreased metabolism of ROS (reactive oxygen species; for example superoxide radicals) and RNS (reactive nitrogen species; for example peroxynitrite). The superoxide anion is generated by several enzymatic reactions, including a variety of NADPH oxidases and uncoupled eNOS (endothelial NO synthase). To relieve the burden caused by this generation of free radicals, which also occurs as part of normal physiological processes, such as mitochondrial respiratory chain activity, mammalian systems have developed endogen…

Gamma interferon administration differently affects sensitive or doxorubicin resistant P388 leukemia cells; a relationship with antioxidant defenses?

1989

Educazione e recalcitranza. Brevi note sulla nozione di paideia in Aristotele

2020

Leonardo Samonà dedica delle interessanti riflessioni al concetto di paideia nel libro Gamma e proprio prendendo spunto da tali riflessioni, pur da una prospettiva diversa e con intenti teorici differenti, il saggio si concentra su questo peculiare uso di paideia che si ritrova nei testi aristotelici, con particolare attenzione alle sue implicazioni in Metafisica Gamma. Un uso che ha a che fare con la questione dei principi primi, con il tema dell'adeguatezza epistemologica e con la relazione conflittuale e problematica con la figura del recalcitrante.

Unit Interval Time and Magnitude Monitoring Using Beta and Unit Gamma Distributions

2022

Quick detection of an assignable cause is necessary for process accuracy with respect to the specifications. The aim of this study is to monitor the time and magnitude processes based on unit-interval data. To this end, maximum exponentially weighted moving average (Max-EWMA) control chart for simultaneous monitoring time and magnitude of an event is proposed. To be precise, beta and unit gamma distributions are considered to develop the Max-EWMA chart. The chart’s performance is accessed using average run length (ARL), the standard deviation of run length (SDRL), and different quantiles of the run length distribution through extensive Monte Carlo simulations. Besides a comprehensive simula…

Beta Decay Studies of Neutron Rich Nuclei Using Total Absorption Gamma-ray Spectroscopy and Delayed Neutron Measurements

2010

International audience; A complete characterisation of the β-decay of neutron-rich nuclei can be obtained from the measurement of β-delayed gamma rays and, whenever the process is energetically possible, β-delayed neutrons. The accurate determination of the β-intensity distribution and the β-delayed neutron emission probability is of great relevance in the fields of reactor technology and nuclear astrophysics. A programme for combined measurements using the total absorption gamma-ray spectroscopy technique and both neutron counters and neutron time-of-flight spectrometers is presented.