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Association of beta-cell-specific expression of endogenous retrovirus with development of insulitis and diabetes in NOD mouse.

The administration of cyclophosphamide to nonobese diabetic (NOD) male mice produces a rapid progression to overt diabetes (greater than 70%) with severe insulitis in 2-3 wk, whereas none of the untreated control NOD male mice became diabetic. When the thin sections of islets from the NOD male mice, which received silica for the preservation of islets and subsequently cyclophosphamide, were examined under the electron microscope, clusters of endogenous retrovirus-like particles (type A) were frequently found in the beta-cells. In contrast, retrovirus-like particles were rarely found in the bet

Expression of CONNEXIN43 is highly sensitive to ionizing radiation and other environmental stresses.

To gain a greater understanding of the mechanisms underlying the cellular responses to low-dose ionizing radiation, gene expression profiles were examined by microarray analysis of cDNA from confluent human diploid fibroblast cultures exposed to very low fluences of alpha-particles. The data, supported by Northern and Western analyses, indicate that radiation induces a significant up-regulation of CONNEXIN43 expression. This phenomenon was observed in a variety of irradiated cell types. These findings are consistent with our previous observations that connexin43 (cx43)-mediated gap-junction in

Radioactivity in bottled waters sold in Mexico.

Measurements of gross alpha and beta activities were made on 21 domestic and international brands of bottled (purified and mineral) water sold in the Mexican market to assess its radiological quality. Alpha and beta activities were determined using a liquid-scintillation detector with pulse-shape analysis feature. All the purified water had values of beta activity lower than the limit for potable drinking water (1.0 Bq/l), while three brands surpassed the limit of alpha activity (0.1 Bq/l). The limit for alpha radioactivity content was exceed by three mineral waters; the results show a correla

In vivo evidence of free radical formation in the rat lung after exposure to an emission source air pollution particle.

Exposure to air pollution particles can be associated with increased human morbidity and mortality. The mechanism(s) of lung injury remains unknown. We tested the hypothesis that lung exposure to oil fly ash (an emission source air pollution particle) causes in vivo free radical production. Electron spin resonance (ESR) in conjunction with the spin trap alpha-(4-pyridyl 1-oxide)-N-tert-butylnitrone (4-POBN) was used to detect radical adducts. Rats were instilled with 500 micrograms of either oil fly ash or saline. Twenty-four hours later, ESR spectroscopy of the chloroform extract from lungs o

The role of macrophages in osteolysis of total joint replacement.

The osteolysis associated with conventional polyethylene on metal total joint replacements is associated with the formation of an inflamed periprosthetic membrane rich in macrophages, cytokines and implant-derived wear particles. There is a wealth of evidence to indicate that the presence and activation of macrophages in the periprosthetic tissues around joint replacements is stimulated by UHMWPE particles. Particles within the size range 0.1-1.0 microm have been shown to be the most reactive. Animal studies have provided increasing evidence that, of the milieu of cytokines produced by particl

Basolateral entry and release of New and Old World arenaviruses from human airway epithelia.

Transmission of arenaviruses from rodent hosts to humans is generally thought to occur through inhalation or ingestion of dust or droplets containing viral particles. Here we demonstrate that two identified arenavirus receptors, alpha-dystroglycan (alpha-DG) and transferrin receptor 1 (TfR1), are expressed in polarized human airway epithelia. Lymphocytic choriomeningitis virus strains with high or low alpha-DG affinity and Junin virus, which binds TfR1, efficiently infected polarized epithelia only when applied to the basolateral surface or when injury compromised tight junction integrity. Vir

Characterization of mode II-wear particles and cytokine response in a human macrophage-like cell culture.

UNLABELLED: Informations about wear particles in metallosis (mode II wear) and their effects in vitro and in vivo are limited. The aim of this study was to characterize wear particles obtained intraoperatively and to analyse their effects on cytokine response in an established human macrophage-like cell culture model. METHOD: Wear particles were obtained intraoperatively from four patients with metallosis resulting from CrCoMo/PE/TiAIV-implants (mode II wear) (3 knee, 1 hip prosthesis). After purification, particles were characterized regarding to their composition and size (particle size ana

Synergistic effects of Al, Ga, and In doping on ZnO nanorod arrays grown via citrate-assisted hydrothermal technique for highly efficient and fast scintillator screens.

To be used as efficient alpha particle scintillator in the fields of nuclear security, nuclear nonproliferation and high-energy physics, scintillator screens must have high light output and fast decay properties. While there has been a great deal of progress in scintillation efficiency, achieving fast decay time properties are still a challenge. In this work, the near band edge (NBE) UV luminescence and alpha particle induced scintillation properties of vertically aligned densely packed ZnO nanorods (NRs) doped with Al, Ga, and In have been thoroughly investigated. The high crystalline hexagon

Induction of apoptosis by protease-defective particle preparations of human immunodeficiency virus type 1 is specific to a subset of U937-derived subclones.

Several recent reports support the hypothesis that apoptosis occurring in leukocytes of human immunodeficiency virus type 1 (HIV-1)-infected individuals is important in progression to AIDS. Specifically, apoptosis of uninfected bystander cells appears critical in the pathogenesis of disease. Here, we present evidence that protease-defective, gp120-containing HIV-1 (L-2) particle preparations specifically induce apoptosis in cells obtained from a subset of promonocytic U937-derived subclones. The rate of apoptosis induction was inversely correlated with the susceptibility of the U937 subclones

Asbestos exposure stimulates pleural mesothelial cells to secrete the fibroblast chemoattractant, fibronectin.

Parietal pleural plaques and visceral pleural fibrosis are well-recognized stigmata of occupational asbestos exposure. However, their pathogenesis is poorly understood. Conceivably, phagocytosis of asbestos fibers by pleural mesothelial cells may stimulate the recruitment of fibroblasts to sites of asbestos-induced pleural injury. To test this hypothesis, rat parietal pleural mesothelial cells were cultured for 6 to 96 h with or without crocidolite or chrysotile asbestos fibers (concentration range, 2 to 100 micrograms/cm2). Asbestos fibers were actively phagocytosed by pleural mesothelial cel

Effects of diesel exhaust particles on human alveolar macrophage ability to secrete inflammatory mediators in response to lipopolysaccharide.

Ambient particulate matter (PM) has been shown to be associated with mortality and morbidity. Diesel exhaust particles (DEP) contribute to ambient PM. Alveolar macrophages (AM) are important targets for PM effects in the lung. The effects of DEP exposure on human AM response to lipopolysachharide (LPS; from gram-negative bacteria) challenge in vitro were determined by monitoring the production of interleukin 8 (IL-8), tumor necrosis factor-alpha (TNF-alpha) and prostaglandin E(2) (PGE(2)). The roles of organic compounds and carbonaceous core of DEP in response to LPS were evaluated by comparin

Evidence for macrophage activation in dialysis patients exposed to silicone filing.

Spleen cell suspensions of 2 dialysis patients with hepatosplenomegaly and pancytopenia were studied in vitro. Spleen cells of a cadaver kidney donor were studied as control. In spleen macrophages of the patients, silicone particles could be demonstrated with TEM and electron microprobe analysis. Under basal conditions and after stimulation with zymosan and concanavalin A, release of PGE2, TXB2 and 6-keto-PGF1 alpha from patient cells was higher than control cells. This anecdotal observation parallels previous animal studies and suggests that loading of human macrophages with foreign material

Thorotrast-induced oro- and hypopharyngeal fibrosis with recurrent bleeding.

Thorium dioxide, widely used as a contrast material, is a producer of alpha particle radiation. This is well demonstrated by autoradiography. The case described illustrates that life-threatening, thorium dioxide-induced pharyngeal haemorrhage may occur even with an occluded carotid artery. The radiation exposure caused an intense foreign body reaction with a marked cell-deficient fibrosis. The alpha particles are well demonstrated by autoradiography. In addition, we were able to show a defect in the wall of the carotid artery due to the Thorotrast injection, which was closed by cell-depleted c…

Astatine-211 based radionuclide therapy: Current clinical trial landscape.

Astatine-211 (211At) has physical properties that make it one of the top candidates for use as a radiation source for alpha particle-based radionuclide therapy, also referred to as targeted alpha therapy (TAT). Here, we summarize the main results of the completed clinical trials, further describe ongoing trials, and discuss future prospects.

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… Numerous preclinical studies have demonstrated dramatic effects using alpha-particle-emitting radionuclides to treat small-scale diseases in mouse models with peritoneal growth of ovarian cancer ( 21 – 23 ). … The rationale for these clinical trials is logical and relates to the possible ability of alpha particles to eradicate single cells and limit the dose to surrounding healthy tissues. …

Responses of 4 X-ray-sensitive CHO cell mutants to different radiations and to irradiation conditions promoting cellular recovery.

Four X-ray-sensitive mutants of CHO cells, described previously by Jeggo and Kemp (1983), showed enhanced sensitivity to both 60Co gamma-rays and 238Pu alpha-particles relative to the responses of the parent line. The enhanced response to a densely ionising radiation (alpha-particles) was less than that to X- or gamma-rays, suggesting that these mutants are deficient mainly in the repair of damage from relatively sparsely ionising radiation tracks. Plateau-phase cultures of the parental CHO cells showed considerable recovery upon irradiation with low-dose-rate gamma-rays, compared to irradiati

Dutasteride nanoemulsion preparation to inhibit 5-alpha-hair follicle reductase enzymes in the hair follicle; an ex vivo study.

Alopecia is a treatable disorder that usually occurs due to high levels of 5-alpha dihydrotestosterone in hair follicles. To enhance the storage capacity of hair follicles and alleviate the inherent characteristics of dutasteride, 5-alpha reductase inhibitor, a prolonged-release nanocarrier was synthesised, and its influence on rat abdomen's skin was investigated. Results showed the lower ratio of S/Co (higher ethanol concentration) increased the hydrodynamic nanocarriers' particle size due to thermodynamic disturbance and Ostwald ripening. In contrast, an increase in surfactant through a decr

Increasing apoA-I production as a target for CHD risk reduction.

Dyslipidemia leading to coronary heart diseases (CHD) enables venues to prevent or treat CHD by other strategies than only lowering serum LDL cholesterol (LDL-C) concentrations, which is currently the most frequently targeted change. Unlike LDL-C, elevated high-density lipoprotein cholesterol (HDL-C) concentrations may protect against the development of CHD as demonstrated in numerous large-scale epidemiological studies. In this review we describe that besides elevating serum HDL-C concentrations by increasing alpha-HDL particles, approaches to elevate HDL-C concentrations by increasing pre-be

Estimation of LET distributions ofα-particles from measured scintillator-based trajectory images.

Objective. Linear energy transfer (LET) measurements ofα-particles are increasingly important for micro-dosimetric evaluation in targetedα-radionuclide therapy. However, direct LET measurements remain challenging due to the extremely short range ofα-particles in matter. In this study, we propose a method to estimate LET distributions using quenching effects observed inα-particle trajectory images.Approach. α-particle trajectories were imaged using an ultra-high-resolution imaging system consisting of a Gd3Al2Ga3O12scintillator, an optical magnification unit, and an electron-multiplying charge-

Energy-resolved imaging ofαparticles emitted by the decay products of Pb-212 using a YAP(Ce)-based imaging detector for targeted radionuclide therapy.

Objective.Lead-212 (Pb-212) is attracting considerable interest as a radionuclide fortargeted α-therapy, yet energy-resolved imaging ofαparticles originating from its decay chain has been technically difficult.Approach.To address this issue, we employed a YAP(Ce)-basedα-particle imaging detector to perform energy-resolved imaging ofαparticles emitted from Pb-212 progeny and evaluated its performance for energy-discriminativeα-particle imaging.Main results.The system provided a spatial resolution better than 1.0 mm full width at half maximum (FWHM) and an energy resolution of approximately 14.9

The effects of particulate wear debris, cytokines, and growth factors on the functions of MG-63 osteoblasts.

BACKGROUND: Particle-challenged cells release cytokines, chemokines, and eicosanoids, which contribute to periprosthetic osteolysis. The particle-induced activation of macrophages and monocytes has been extensively studied, but only limited information is available on the response of osteoblasts to particulate wear debris. This study examines the effects of particulate wear debris, proinflammatory cytokines, and growth factors on osteoblast functions. METHODS: MG-63 osteoblasts were treated with metal particles (titanium, titanium alloy, and chromium orthophosphate) or polymeric particles (po