Ileal uptake of polyalkylcyanoacrylate nanocapsules in the rat.

The ileal uptake of polyalkylcyanoacrylate nanocapsules (less than 300 nm in diameter) has been investigated in the rat. Iodised oil (Lipiodol) was used as the tracer for X-ray microprobe analysis in scanning electron microscopy. Lipiodol nanocapsules, or an emulsion of Lipiodol, were administered in the lumen of an isolated ileal loop of rat.

A possible role of collagen fibrils in the process of calcification observed in the capsule of the pineal gland in aging rats.

The relationship between collagen fibrils and calcified concretions exclusively appearing in the pineal gland of adult/aging rats has been investigated. Deposits of lanthanum, which replace calcium ions are distributed along collagen fibrils with a repeating period of about 70 nm. Calcium has been detected histochemically between collagen bundles surrounding extracellular concretions by means of the pyroantimonate method and by X-ray microanalysis.

Electron probe X-ray microanalysis of the elemental composition of the pineal gland of young adults and aged rats.

Fractures of deep-frozen and freeze-dried pineal glands were analysed for elemental composition by means of X-ray microanalysis with a scanning electron microscope. The results from young adults (3 months old) were compared with those from aged animals (24 months old); significant increases in S, Ca, Al, Si, and Fe were observed in aged animals when compared to young adults. There were no significant differences with Na, Mg, Cl, K, Ti, Cr, Mn, Ni, Cu, Zn, whereas a decrease of P was observed in aged animals when compared to young adults.

Calcium concretions in the pineal gland of aged rats: an ultrastructural and microanalytical study of their biogenesis.

The genesis of calcium concretions in aged rats was studied by means of transmission and scanning electron microscopy. The potassium pyroantimonate method, combined with X-ray microanalysis, allowed us to study the distribution of cations and calcium. Notable accumulations of calcium (associated with phosphorus) were localized in vesicles, vacuoles, lipid droplets, lipopigments, and mitochondria of dark pinealocytes.

The pineal gland of the aging rat: calcium localization and variation in the number of pinealocytes.

In the present study, we investigated the population of pinealocytes in the pineal gland of aging rats. Dark and light pinealocytes were analyzed as to their calcium content. Calcium localization was realized in dark and light cells by means of cytochemistry and X-ray microanalysis.

Permeability of the pineal gland of the rat to lanthanum: significance of dark pinealocytes.

The permeability of the pineal gland to lanthanum was investigated by means of transmission electron microscopy and X-ray microanalysis. Different pineal cell populations were studied. Light pinealocytes as well as glial cells were not permeated by the tracer lanthanum, which normally stays extracellularly.

Calcium content and concretions of pineal glands of young and old rats. A scanning and X-ray microanalytical study.

Calcium content and pineal concretions were studied in young (2-3 months) and old (28 months) Wistar rats. Samples, deep-frozen by liquid propane isopentane and freeze-dried were analysed by means of X-ray microanalysis in a scanning electron microscope. Total semi-quantitative measurements revealed that pineals of old rats showed a marked increase of calcium compared with the pineals of young rats.

Role of intestinal mucus in crystal biogenesis: an electron-microscopical, diffraction and X-ray microanalytical study.

In the posterior intestine of the sea-water eel, mucus plays an important role in biocrystallization of calcium ions. By means of transmission and scanning electron microscopy associated with X-ray microanalysis and X-ray diffraction it has been possible to determine the role of mucous fibers as nucleation sites. Biocrystallization occurs in 2 steps: (1) Calcification of mucus.

Transmucosal passage of polyalkylcyanoacrylate nanocapsules as a new drug carrier in the small intestine.

The enteral absorption of particles has been investigated in the dog using a colloidal drug carrier, polyalkylcyanoacrylate nanocapsules loaded with an iodized oil (Lipiodol), as a tracer for X-ray microprobe analysis in a scanning electron microscope. Nanocapsules are spherical capsules, 100 to 200 nm in diameter, with a continuous polymeric wall surrounding a cavity which encapsulates the drug. Administered in the jejunal lumen, Lipiodol nanocapsules improved the absorption of the tracer as indicated by increased concentration of iodine in the plasma of mesenteric blood.

Is mucus involved in biocrystallization? Study of the intestinal mucus of the sea-water eel Anguilla anguilla L.

Freeze-dried intestinal mucus of sea-water-adapted eels was analysed by scanning electron microscopy (SEM) and X-ray microanalysis. Calcite crystals were observed in the mucus fibres; their concentration increased along the hindgut. Random SEM observations made in situ indicated that mucus fibres were involved in the genesis of these crystals.

Effects of wheat bran on the exocrine pancreas and the small intestinal mucosa in the dog.

Five Beagle dogs, equipped with duodenal and gastric fistulae, were fed a standard diet before receiving the same diet supplemented with wheat bran for 1 month. Pancreatic secretory investigations performed in conscious animals before and 1 month after bran administration showed a significant parallel increase in the flow rate of pancreatic secretion and the outputs of bicarbonate and amylase both in basal and secretin-stimulated conditions. The outputs of protein and chymotrypsin increased only in unstimulated secretions, while the output of lipase was strongly reduced in response to secretin.

Pancreatic hyperplasia after small bowel resection in the rat: dissociation from endogenous gastrin levels.

Extensive small bowel resection produces pancreatic hyperplasia and increases plasma gastrin levels in the rat. Because gastrin is known as a trophic factor for the exocrine pancreas, we studied the effect of endogenous variations of gastrin induced by different gastric operations on the rat pancreas in both resected and transected animals. Vagotomy increased plasma gastrin level while antrectomy decreased it; pyloroplasty was without any effect.

Protein malnutrition after jejunoileal bypass in the rat. Possible contribution of the exocrine pancreas and the included intestine.

A 90% jejunoileal bypass induces in the rat a protein malnutrition state which is characterized (1) by the decreased level of plasma proteins and albumins and (2) by the reduced level of most essential and non-essential plasma amino acids. In the exocrine pancreas there was a decreased content of digestive enzymes, especially of amylase, while the secretion of enzymes studied in vitro was reduced. In the ileum left in one piece, the specific activities of maltase and sucrase increased significantly while aminopeptidase was unaffected.

A morphological study on gills of a crab acclimated to fresh water.

The gills of the fully euryhaline Chinese crab Eriocheir sinensis were studied by light and electron microscopy. In these Phyllobranchiates, the gills consist of a double row of lamellae extending laterally from a central shaft. Haemolymph flow pattern inside the gill is described and the existence of a complex secondary vascularization inside the platelets is reported.

Copper accumulation in primary biliary cirrhosis. An electron and X-ray microanalytical study.

Ultrastructural and X-Ray microanalytical aspects of primary biliary cirrhosis were analysed and compared to those of normal liver. Electron microscopic studies showed a significant increase of dense lipofuscin-like granules in PBC compared to the hepatocytes of normal liver (665%). These granules (0.

Effect of obstructive jaundice on wound healing. An experimental study in rats.

The effect of obstructive jaundice on wound healing was investigated in an experimental study of gastric and abdominal wounds in rats after ligation and division of the common bile duct. The healing of a parietal defect in these animals showed histologic evidence of delayed healing compared with controls. The bursting strength of the abdominal incision was also decreased, but not that of the stomach.

The midgut of Tomocerus minor Lubbock (insecta, collembola): ultrastructure, cytochemistry, ageing and renewal during a moulting cycle.

The midgut cells of Tomocerus minor (Insecta, Collembola) were examined with the electron microscope and cytochemically. The midgut epithelium consists of a series of cells characterised by numerous mineral concretions scattered throughout the cytoplasm. Mitochondria are abundant; microvilli are well developed at the apical surface of the cell.

[The reaction of the insect excretory tissue to a heavy metal: uranyl nitrate (author's transl)].

The present paper describes the modifications induced in Malpighian tubules of Locusta migratoria by uranyl nitrate. These modifications are observed only if doses injected are approximately a hundred times higher than those which affect the renal epithelium of Vertebrates. The elimination of the uranyl salts seem to occur by apical excretion of dense metallo-proteic granules.

Intracellular and intramitochondrial binding of lanthanum in dark degenerating midgut cells of a collembolan (insect).

Lanthanum is known to be a marker of extracellular spaces. Intracellular organelles are always devoid of stain. But dark and damaged cells may be entered by the marker, as studied at the cellular level, using the electron probe X-ray microanalyser.

Cytochemistry and x-ray microprobe analysis of the midgut of Tomocerus minor lubbock (insecta, collembola) with special reference to the physiological significance of the mineral concretions.

Histochemical and cytochemical analyses have been made on the mineral concretions within the midgut cells of Tomocerus minor. The classical histochemical methods are not specific and precise enough and have been supplemented with cytochemical techniques on ultrathin sections. The most interesting of these was the K-pyroantimonate technique combined with glutaraldehyde-osmium fixation.