Electron Microscopy of Rat Liver after Intravenous Injection of Nanosized Magnetite Suspension

Rat liver was examined by transmission electron microscopy after a single intravenous injection of nanosized magnetite suspension (0.1 g (Fe(3)O(4))/kg body weight). Magnetite particles were found in Kupffer's cells and hepatocytes. Accumulation of the particles by these two cell types was different. Morphometry of magnetite-containing granules in Kupffer's cells and nanoparticle agglomerations in hepatocytes was carried out. The ultrastructure of Kupffer's cell granules was described and the mechanism of penetration of nanosized magnetite particles into the cells was suggested. Nanosized magnetite particles were not completely eliminated over 40 days after a single injection.     

Rat Blood Leukocytes after Intravenous Injection of Magnetoliposomes on the Basis of Nanomagnetite

Bulletin of Experimental Biology and Medicine - The structure of blood neutrophils, eosinophils, monocytes, and lymphocytes and differential white blood count in adult rats were studied over 120...     

Evaluation of a Luer-Activated Intravenous Administration System

Needlestick and other sharps-related injuries are largely preventable with proper education, training, and the use of safety-engineered devices. In 2009, a review of clinical practice was completed at Thunder Bay Regional Health Sciences Centre. The review revealed that despite needle-free legislation, numerous years of education on the dangers of using needles, and the availability and importance of using safety devices, nurses and physicians continued to use needles when accessing intravenous tubing to administer medication.During 2010, a luer-activated intravenous administration system was introduced to replace the current split-septum intravenous administration system. Implementation of the luer-activated system was expected to decrease needlestick injuries, positively affect nursing practice, and demonstrate a commitment to a safe working environment. Reported needlestick injuries were reviewed and analysed pre- and post-implementation and a survey on nurse perception of the new system and organizational safety was distributed.Results showed that there was a 46% decrease in needlestick injuries post-implementation, along with 80% of nursing staff reporting that the new system had a positive influence on their nursing practice and belief that the organization was committed to providing a safe work environment.The results of this study emphasize and support the replacement of needles with alternative needleless products to improve the safety of the work environment.     

Hemopoietic Efeece of Intravenous Soujble Glucan Administration

Abstract

A soluble form of the reticuloendothelial- and immune modulating agent glucan (glucan-F) has been evaluated for its effects on hanopoiesis. A single 5.0 mg intravenous injection of glucan-F into C3H/HeN mice increased peripheral white blood cellularity, bone marrow and splenic cellularity, bone marrow and splenic granulocyte-macrophage progenitor cell numbers (GM-CFC), and splenic pluripotent stem cell (CFU-s) and erythroid progenitor cell (CFU-e) numbers. Serum levels of granulocytemacrophage colony stimulating activity (CSA) were also elevated following glucan-F administration. These hemopoietic responses correlate well with those previously shown to be induced by intravenous administration of particulate glucan (glucan-P). In contrast to glucan-P, however, intravenous glucan-F administration has been shown not to induce granuloma formation and severe hepatosplenomegaly, thus the potential clinical use of glucan-F as a hemopoietic stimulant is more likely than that of glucan-P.     

Hemopoietic Efeece of Intravenous Soujble Glucan Administration

A soluble form of the reticuloendothelial- and immune modulating agent glucan (glucan-F) has been evaluated for its effects on hanopoiesis. A single 5.0 mg intravenous injection of glucan-F into C3H/HeN mice increased peripheral white blood cellularity, bone marrow and splenic cellularity, bone marrow and splenic granulocyte-macrophage progenitor cell numbers (GM-CFC), and splenic pluripotent stem cell (CFU-s) and erythroid progenitor cell (CFU-e) numbers. Serum levels of granulocytemacrophage colony stimulating activity (CSA) were also elevated following glucan-F administration. These hemopoietic responses correlate well with those previously shown to be induced by intravenous administration of particulate glucan (glucan-P). In contrast to glucan-P, however, intravenous glucan-F administration has been shown not to induce granuloma formation and severe hepatosplenomegaly, thus the potential clinical use of glucan-F as a hemopoietic stimulant is more likely than that of glucan-P.     

Changes in the Ultrastructure of the Rat Cerebral Cortex after Oral Doses of Manganese Chloride

Neuroscience and Behavioral Physiology -     

Evidence of Hepatocyte Apoptosis in Rat Liver after the Administration of Carbon Tetrachloride

In acute liver injury induced by the injection of CCl₄, cell death has been attributed to the necrosis of hepatocytes in the centrilobular area. In the present study, we re-examined the hepatic injury evoked by CCl₄ in rats and explored the possibility that apoptosis may also contribute to its pathogenesis. Apoptotic hepatocytes were identified and quantified by light and electron microscopy, the in situ immunohistochemical labeling of nuclear DNA fragmentation, flow cytometry, and DNA gel electrophoresis. We found that a substantial number of hepatocytes underwent apoptosis. Apoptotic changes were also observed in ballooned hepatocytes. Apoptotic hepatocytes increased in number at 3 hours and peaked at 6 hours after the CCl₄ injection. Apoptotic bodies were sequestrated in the adjacent hepatocytes and sinusoidal cells. Double staining of the cells with immunostaining for phagocytes and terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling staining for labeling of DNA fragmentation showed that the majority of apoptotic hepatocytes were phagocytosed by Kupffer cells and macrophages. The results indicated that apoptosis occurs in the ballooned and injured hepatocytes of the centrilobular area. What occurs after CCl₄ administration may be important in reducing inflammation, shortening the course of acute hepatic injury, and preventing the development of fibrosis.     

Observations of the Early Diuretic Response after Intravenous Administration of Bumetanide and Furosemide in Dogs

A transient natriuretic peak was observed in dogs the third minute after the i.v. administration of the highly active diuretics bumetanide and furosemide. The peak is dependent on the sodium balance such that it is potentiated during positive sodium balance and is not observed in sodium depleted dogs. A relationship exists between the simultaneous occurrence of the peak and abolition of the cortico-medullary electrolyte gradient.     

Changes in Neuropil Ultrastructure in Hippocampal Field CA1 in Rat Pups after Application of Hyaluronidase

Electron microscopy and electrophysiological studies were performed on cross-sectional slices of the hippocampus of four-week-old male rat pups (n = 35) to detect ultrastructural changes in hippocampal field CA1 and the characteristics of the formation of excitatory postsynaptic potentials in this area of the brain after incubation of slices in hyaluronidase solution (10 U/ml), whose specific substrate is the extracellular matrix glycosaminoglycan hyaluronic acid. At 1.5 min after enzyme application, there were reductions in synaptic cleft widths in axodendritic contacts of the striatum radiatum of hippocampal field CA1 by 15–25%, which were consistent with increases seen in the amplitudes of excitatory postsynaptic potentials. At 4.5 min of incubation, the lumens of synaptic clefts decreased by 45–55%: during this time there was blockade of signal transmission via Sch?ffer collaterals to hippocampal field CA1. Thus, the structural-functional state of glycosaminoglycans is among the factors determining the efficiency of synaptic transmission in the brain. Translated from Morfologiya, Vol. 133, No. 4, pp. 11–14, July–August, 2008.     

Intermittent Intravenous Administration Sets: Survey of Current Practices

The practice of using intravenous (IV) administration sets for intermittent infusion is subject to much controversy and there is no scientific data to validate the practice. To get an idea of this practice, an online survey was sent to approximately 4000 nurses, with 361 responding. The results highlight the vast differences in practice between the clinical settings of the available studies and how these sets are currently used. Although no recommendations for practice can be drawn from these data, they emphasize the urgent need for research on the use of intermittent administration sets and their contribution to the incidence of catheter-related bloodstream infection.     

Ultrastructure of Hippocampal Field CA1 in Rats after Status Epilepticus Induced by Systemic Administration of Kainic Acid

The ultrastructure of hippocampal field CA1 in rats was studied 14 days after status epilepticus induced by administration of kainic acid. Structural changes were seen in 40% of cells, predominantly interneurons, which showed both reversible changes (mitochondria with an electron-dense matrix or small numbers of short cristae, moderate dilation of rough endoplasmic reticulum (RER) cisterns, and small numbers of ribosomes) and more significant abnormalities: swollen mitochondria with very small numbers of cristae, which were partially degraded, some with damaged mitochondrial membranes, along with pathologically damaged RER components and focal or peripheral chromatolysis. Chromatolyzed areas sometimes contained membrane-like includes and vacuoles. In addition, the neuropil contained occasional large osmiophilic formations surrounded by astrocyte processes with accumulations of glycogen or gliofibrils. Synaptoarchitectonics were also altered. Asymmetrical synapses were often seen on small dendrites and spines, with highly osmiophilic postsynaptic zones, their synaptic terminals containing numerous synaptic vesicles and large vesicles with electron-dense cores. Some presynaptic endings showed clear signs of classical dark-type degeneration. As the nucleus remained intact in all types of altered neurons, it appears that most cells underwent pathological changes of the necrotic type.     

Delayed Nootropic Effects of Arginine Vasopressin after Early Postnatal Chronic Administration to Albino Rat Pups

Intranasal administration of arginine vasopressin (10 μg/kg) to albino rat pups had a strong nootropic effect during training with positive and negative reinforcement. This effect was different in animals of various age groups: training with positive reinforcement was improved in “adolescent” rats and pubertal animals, while during training with negative reinforcement, the nootropic effect of the peptide was more prolonged and persisted also in adult animals.     

Effects of Biliary Obstruction on Pulmonary Ultrastructure in the Rat

Hypoxemia and respiratory alkalosis have been described in patients with liver disease. Since no pulmonary parenchymal lesions have been related to the abnormal respiratory function, the effects of common bile duct ligation and division on pulmonary alveolar structure were studied in ninety-two 10- to 14-week-old male Wistar rats. In comparison with controls, the rats with ligated common bile ducts (CBD) developed progressive hepatic and pulmonary changes. The hepatic damage consisted of bile duct proliferation, loss of hepatocytes and generalized cirrhosis. Most pronounced pulmonary histologic differences between the CBD and sham-operated rats were thickening of interalveolar septa and generalized increase in cellularity of alveolar walls. With electron microscopy, frequently observed alterations included swelling and increased vacuolization of endothelial and epithelial (Type I) cells, proliferation of Type II alveolar pneumonocytes, and increase in amounts of collagen fibers and edema of the interstitium.