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Biomedical subjects

P Galle

Publications and source records attributed to P Galle.

At least 19 recordsLinked to original sources
PubMed1996

Hepatitis B virus nucleic acids associated with human peripheral blood mononuclear cells do not originate from replicating virus.

There have been numerous reports suggesting that human peripheral blood mononuclear cells (PBMCs) can be productively infected with human hepatitis B virus (HBV). We therefore examined whether the PBMCs can be used to establish an in vitro infection system for HBV. Freshly purified PBMCs were incubated with HBV with or without mitogen stimulation. Successful infection was tested using a newly developed PCR method that can differentiate between the relaxed circular (RC) DNA of the virus inoculum and the covalently closed circular (CCC) DNA which is formed only after successful virus entry. This method enables virus uptake to be proven even if the infection is abortive because there is no gene expression because of the lack of liver specific gene expression factors. All attempts to detect CCC DNA after incubation of PBMCs with HBV failed. On the contrary, CCC DNA could easily be detected in infected liver or after in vitro infection of primary human hepatocytes. Because this result appeared to be contradictory to the published data, we analyzed PMBCs isolated from infected patients. We could confirm that HBV DNA and RNA are associated with these cells. However, even after restimulation with mitogens, we could only detect RC DNA. Moreover, we could also demonstrate that viral RNA is present in free virus. Apparently, a certain amount of defective particles do not reverse transcribe the packaged pregenomic RNA. In summary we found no evidence that PMBCs can be infected with HBV and conclude that all previous observations can be explained by adsorbed virus.

Base Sequence↗
PubMed1996

[Early ultrastructural lesions of kidney cells after intravenous administration of 239 plutonium citrate in rats].

After intravenous administration of (5 x 2.3 kBq and 5 x 9.25 kBq) plutonium citrate in adult male Sprague Dawley rats, their kidneys are withdrawn and prepared for observation under a transmission electron microscope. Seven days after the first injections, deep cellular alterations are observed in the proximal convoluted tubules. These alterations are mainly mitochondrial. The affected mitochondria are of swollen aspect and have their cristae partially or completely destroyed. Nevertheless within the same tubule we observe non altered cells directly in contact with deeply altered cells. In all the cases the lysosomes of the altered cells appear to be perfectly normal. The cell nuclei are mostly unaltered but a few cases of nuclear fragmentation exist. We also notice some architectural modifications in the brush border and in the betacytomembranes of the proximal convoluted tubule. Equally important mitochondrial alterations are also noticed in the different varieties of glomerular cells. We observe no other glomerular alterations. The major subcellular alterations in the proximal convoluted tubules and in the different varieties of glomerular cells deeply contrast with the distal convoluted tubules which are found to be totally unaltered. These mitochondrial alterations may be due to the alpha particle disintegration of plutonium which may either directly react with the mitochondria or, through the products of radiolysis of water react with the mitochondria respiration process. However the direct chemotoxicity of plutonium cannot be neglected.

Animals↗
PubMed1995

Intranuclear sites of Np 237 in mammalian cells: a study using electron microscopy and electron probe microanalysis.

Two methods, electron microscopy and wavelength dispersive electron probe microanalysis, were used to determine the intracellular sites and chemical form of concentrations of neptunium nitrate 237 after chronic intoxication by the intraperitoneal route in two organs in the rat known to concentrate this element (kidney, liver). Abnormal intranuclear formations in the form of clusters of dense granules containing neptunium, phosphorus, sulphur, and calcium were found in the nuclei of kidney proximal tubule cells and hepatocytes. These formations had a maximum diameter of the order of 2 microns and were located in the central part of the nucleus, away from the nucleolus and peripheral chromatin. Serious nuclear and cytoplasmic ultrastructural lesions are often associated in cells containing neptunium inclusions. The absorbed doses in the kidney and the liver were very low. A relationship between these abnormal intranuclear structures and the carcinogenic effect of neptunium remains to be clarified. This effect is related more probably to the chemical toxicity of Np 237.

Animals↗
PubMed1995

Primary hyperparathyroidism: is technetium 99m-Sestamibi/iodine-123 subtraction scanning the best procedure to locate enlarged glands before surgery?

Technetium99m (99mTc)-Sestamibi/123I subtraction scanning was prospectively performed in 30 patients with primary hyperparathyroidism in an attempt to locate enlarged glands before first surgery. Imaging results were compared to surgical findings; the surgeon tried to identify all parathyroid glands. Twenty-seven patients were found to have a solitary adenoma during surgery, and 3 had multiglandular parathyroid hyperplasia. Twenty-six parathyroid adenomas (96%) were accurately located before surgery. The smallest gland detected weighted 125 mg. Preoperative detection of two mediastinal adenomas allowed them to be excised by median sternotomy during the initial operation. 99mTc-Sestamibi/123I subtraction scanning predicted multiglandular involvement in two patients with parathyroid hyperplasia, whereas it showed a solitary image in the third. Ten patients (33%) had associated nodular thyroid disease, hindering image analysis and leading to one false positive result. 99mTc-Sestamibi scanning seems to be better for locating enlarged parathyroid glands than other noninvasive imaging techniques. However, 1) difficulties associated with thyroid nodules call for complementary thyroid scanning; and 2) images showing a solitary enlarged parathyroid gland do not rule out multiglandular disease. This technique should help in detecting lesions, such as mediastinal glands, that are difficult to find at initial surgery.

Adult↗
PubMed1995

Interaction of selenium with copper, silver, and gold salts. Electron microprobe study.

The interaction of selenium with elements of group 1b of the periodic system, i.e. copper, silver, and gold was studied. Electron probe microanalysis was used to detect elements in intracellular organelles. Administration of copper, silver, or gold salts (the latter being used in chrysotherapy) showed that these elements were concentrated in the lysosomes of the liver or kidney in the presence of sulfur. Silver salts were also precipitated in glomerular basement membranes. The action of selenium enhances this intralysosomal process of concentration and precipitation. Sulfur and selenium are detected in the lysosome and this makes identification of the precipitate difficult. The action of selenium, which consists in removing toxic elements from the systemic circulation and concentrating them in the lysosomes, is in most cases beneficial for the organism. This mechanism, which has already been studied for arsenic, is extended in this study to other elements.

Animals↗
PubMed1995

Scanning ion microscopy mapping of basement membrane elements and arterioles in the kidney after selenium-silver interaction.

The effects of selenium and silver salts was studied by scanning ionic microscopy during experimental argyria mapping of the different basement membrane elements. The ionic microscope (IMS 4F) was equipped with a high resolution spectrometer giving high spatial resolution on the image obtained. After long-term treatment with silver salt alone, silver and sulphur deposits were observed in the membranes. After administration of selenium and silver salt, it was possible to map nitrogen, sulphur, selenium and silver to the glomerular basement membrane as well as to the wall of the kidney arterioles. In the latter, sulphur, selenium and silver were localized only in the elastic laminae of the walls. This process of precipitation of silver deposits in the membrane can be interpreted as process of selenium "detoxification" of the organism.

Animals↗
PubMed1995

Subcellular localization of gadolinium injected as soluble salt in rats: a microanalytical study.

The rare earth gadolinium (Gd) is used in modern industry. Solubilized DTPA Gd and DOTA Gd complexes are used as contrast media in nuclear magnetic resonance imaging. In order to determine the subcellular localization of Gd, rats were injected intraperitoneally with Gd nitrate. Two microanalytic methods, ion microanalysis and electron microprobe, enabled the distribution and the intracellular localization of Gd to be determined in the liver, spleen, bone marrow, kidneys and lung. The results showed: a) a punctual distribution of Gd in the tissues (liver, spleen, bone marrow and lung) as observed by ion microscopy; b) a selective concentration of Gd in the lysosomes of macrophages of the liver (hepatocytes), spleen (macrophages), bone marrow (macrophages) and lung (phagocyte cells), as determined by electron probe X-ray microanalysis. In all these sites the Gd is associated to phosphorus. Results are compared to those found for other rare earths and metal elements.

Animals↗
PubMed1994

Advantages of the scanning ion microscopy for mapping halogen corticoids in normal and transformed cells in culture.

The intra-cellular distribution of eight halogen glucocorticoids was investigated by ion microscopy in two cellular varieties of cultured non-cancer cells (fibroblast 3T3) and cancer cells (human breast tumor cells MCF-7). Two types of ion microscopy helped to determine this distribution, a direct imaging ion microscope (SMI 300) with low spatial resolution, and a scanning ion microscope (IMS4F), featuring high resolution, serving to obtain maps representing the intra-cellular distribution of the fluorine elements and drugs present in these monolayer cultured cells. The fluorine images representative of the drugs containing fluorine showed that these drugs are essentially concentrated in the cell nuclei. In these nuclei, the distribution of these drugs is different from that of heterochromatin and of the nucleolus.

3T3 Cells↗
PubMed1994

Detection and cartography of the fluorinated antimalarial drug mefloquine in normal and Plasmodium falciparum infected red blood cells by scanning ion microscopy and mass spectrometry.

Due to the presence of fluorine atoms in its molecule, the antimalarial drug mefloquine (MQ) can be easily detected in normal and Plasmodium falciparum infected red blood cells (RBC) by scanning ion microscopy and mass spectrometry. The P falciparum infected RBC exhibited intense distribution of MQ inside the parasite. The main compartments of the parasite which accumulate the drug were the food vacuole and the cytoplasm. The correlation between fluorine (19F-) and phosphorus (31P-) as well as probes for the DNA synthesis (BrdU and IdU) emissions shows that the parasite nucleus is also accessible to the drug. This study demonstrates that SIMS technique on smear preparations is an efficient approach for the direct detection and cartography of fluorinated antimalarial drugs in normal and P falciparum infected RBC, without radioactive labelling.

Animals↗
PubMed1994

Subcellular localization of gold in suprarenal testicle and thyroid glands after injection of allochrysine in rats.

Gold injected under the form of anti-rheumatoid polyarthritis soluble solutions provokes, as observed by electron microscope, a deposit of crystalline micro-needles in different tissues, like in cells of adrenal and suprarenal glands, in Leydig cells of the testicles, in isolated thyrocytes and in thyroid endothelial cells. They are present as bundles, often of incurvated type, of high electron-density, present in lysosomes, which contain moreover a hyaline, emptied vesicle. These structures are named "aurosomes". The microanalysis, using the MS 46 (Cameca) and the Camebax (MBX) demonstrates that these crystalline structures are composed by gold associated with sulphur, and not with phosphate.

Animals↗
PubMed1994

Selenium-arsenic interaction in renal cells: role of lysosomes. Electron microprobe study.

Selenium can modify the toxicity of different elements. Selenium and the element form a complex that is precipitated in the tissues and inhibits the toxicity of the element. We studied the interaction of arsenic and selenium at the subcellular level in rat kidney cells using electronic probe microanalysis that permits detection of elements in the intracellular organelles. This showed that arsenic and selenium are concentrated and precipitated in the lysosomes of the renal cells in the form of insoluble selenide (As2Se). In the long term, the lysosomes and their precipitate are eliminated in the urine. These processes enable the lethal toxicity of arsenic to be inhibited. This intralysosomal concentration and precipitation can serve as a model for the mechanism of interaction of selenium with other elements and can be compared with other mechanisms of concentration and precipitation of elements in the lysosomes.

Animals↗
PubMed1993

Selective intra-lysosomal concentration of niobium in kidney and bone marrow cells: a microanalytical study.

Niobium is used as an alloy in the industrial and biomedical fields. The concentration of the toxic element in organs of a number of animal species has been defined by using radioactive niobium (95Nb). However, tissue lesions induced by niobium have only been studied at the light microscopy level. In this study, we used an electron probe X-ray analyzer equipped with a transmission electron microscope to define the localization of this element in kidney and bone marrow cells. Results demonstrated that niobium is located in the lysosome and that this element coprecipitates with phosphate. In kidney, lysosomes and precipitates are eliminated in the tubular lumen. In contrast, precipitates appear to be eliminated more slowly from the lysosomes of bone marrow macrophages. These processes therefore correspond to one of the mechanisms by which lysosomes eliminate certain toxic mineral elements and thus play a role in the more general process of the body's defenses.

Animals↗
PubMed1992

Mapping the cellular distribution of labelled molecules by SIMS microscopy.

We took advantage of one of the main possibilities of ion microscopy, ie isotopic analysis, to study the cellular distribution of molecules labelled either with carbon 14 or with stable isotopes of low natural abundance such as nitrogen 15 and deuterium. The surface of the sample is bombarded with an ion beam (O2+, Cs+ etc). Secondary ions emitted from the sample are filtered by a mass spectrometer and the distribution of the labelling isotope is recorded. In this way, we obtained images showing the characteristic distribution of 14C-thymidine and D-arginine in human fibroblasts, and of 15N-adenine in organotypic cultures of human breast cancer cells. The spatial resolution on the acquired images was close to 0.1 micron when using the UPS-ONERA ion microprobe. The sensitivity of the method for detecting carbon 14 is far greater than that of autoradiography and the technique is both fast and quantitative. On the other hand, the capacity of ion microscopy for studying the tissular distribution of molecules labelled with stable isotopes, opens the way for biological and pharmacological tracer studies of human diseases.

Adenine↗
PubMed1992

SIMS microscopy: a tool to measure the intracellular concentration of carbon 14-labelled molecules.

Monolayer cultures of human fibroblasts were incubated for 24 h with 14C-arginine and observed by means of SIMS microscopy (ion microscopy). Carbon 14 imaging showed the intracellular distribution of labelled arginine which featured high nuclear incorporation. The local concentration of this amino acid in different cells and intracellular structures was assessed through local isotopic 14C/12C ratio measurement. This relates the signal intensity of the labelling isotope carbon 14 to that of the corresponding natural isotope (carbon 12) of known tissular concentration. Using this method we were able to measure minor variations in the molecular concentration of arginine (expressed as mumol/g of tissue) between different fibroblasts. Results of this study indicate that SIMS microscopy is well adapted to carbon 14 detection and can provide quantitative maps of the cellular and subcellular distribution of 14C-labelled molecules.

Adult↗
PubMed1992

Mapping of intracellular halogenous molecules by low and high resolution SIMS microscopy.

The subcellular distribution of halogenous molecules has been studied by SIMS microscopy in cultured cells of a human breast carcinoma (MCF-7 cell line). Two instruments of microanalysis were used. A low lateral resolution ion microscope (SMI 300 CAMECA) and a prototype scanning ion microscope equipped with a cesium gun that gives high lateral resolution images. This apparatus has been developed by G Slodzian, in Onera Laboratories (Office National d'Etudes et de Recherches Aérospatiales). Molecules studied by low lateral resolution ion microscope were halogenous steroids: fluorometholone, triamcinolone, bromocriptine and bromoandrosterone. Analytical images show that the first two compounds are mainly localized in the nuclear structure of MCF-7 cells whereas the last two molecules are localized in cytoplasm of these cells. Images were obtained with a resolution of 1 micron. With the scanning ion microscope, it is now possible to obtain images at the ultrastructural level. Four analytical images can be simultaneously obtained by a single scan of the imaged area, corresponding to a depth of erosion of the section of ten nm. The intranuclear distributions of three pyrimidine analogs, 5-bromo-2'-deoxyuridine, 5-iodo-2'-deoxyuridine and 5-fluorouracil have been studied in phase S and M of MCF-7 cells and these images have been compared to the distribution of sulfur, nitrogen and phosphorus. All these images have been obtained with a lateral resolution better than 100 nm.

Adrenal Cortex Hormones↗
PubMed1992

Subcellular localization of two neurotropic drugs in three varieties of central nervous system cells by secondary ion mass spectroscopy (SIMS) microscopy.

The intracellular localization of two neurotropic drugs, flunitrazepam (benzodiazepine) and triflupromazine (phenothiazine), was studied by secondary ion mass spectrometry microscopy (SIMS) in three varieties of cells. The images of the intracellular distributions of the two drugs are easily obtained by selecting the fluorine atom of the molecules. These images show that the drug from the benzodiazepine group is mainly located in the nuclei, whereas the phenothiazine is exclusively located inside the cytoplasm.

Animals↗
PubMed1992

Role of alveolar macrophages in precipitation of mineral elements inhaled as soluble aerosols.

The lysosomes of several varieties of cells such as the tubular proximal cell of the kidney and the alveolar macrophage have the ability to concentrate and precipitate several elements inhaled in water-soluble form, usually as phosphate. The mechanism involved is attributed to the high acid phosphatase activity of lysosomes and can be considered as an in vivo Gomori reaction. Among the elements studied, most of them are chemotoxic or radiotoxic (Cr; group IIIA: Al, Ga, In; rare earths: La, Ce, Tm; actinides: Th, U). In the lung macrophage, this mechanism of intralysosomal concentration and precipitation may prevent the diffusion of these toxic elements through the alveolar membrane.

Aerosols↗