Development, differentiation, and vascular components of subcutaneous and intrahepatic Hepa129 tumors in a mouse model of hepatocellular carcinoma.

Tumor models in mice offer opportunities for understanding tumor formation and development of therapeutic treatments for hepatocellular carcinoma. In this study, subcutaneous or intra-hepatic Hepa129 tumors were established in C3H mice. Tumor growth was determined by daily measurements of subcutaneous tumors and post-mortem studies of subcutaneous and intrahepatic tumors.

Use of labeled tomato lectin for imaging vasculature structures.

Intravascular injections of fluorescent or biotinylated tomato lectin were tested to study labeling of vascular elements in laboratory mice. Injections of Lycopersicon esculentum agglutinin (tomato lectin) (50-100 µg/100 µl) were made intravascularly, through the tail vein, through a cannula implanted in the jugular vein, or directly into the left ventricle of the heart. Tissues cut for thin 10- to 12-µm cryostat sections, or thick 50- to 100-µm vibratome sections, were examined using fluorescence microscopy.

Neurotrophic factors rescue basal forebrain cholinergic neurons and improve performance on a spatial learning test.

This study investigated whether animals sustaining experimental damage to the basal forebrain cholinergic system would benefit from treatment with exogenous neurotrophic factors. Specifically, we set out to determine whether neurotrophic factors would rescue damaged cholinergic neurons and improve behavioral performance on a spatial learning and memory task. Adult rats received bilateral injections of either saline (controls) or 192 IgG-saporin to damage basal forebrain cholinergic neurons (BFCNs).

Characterization of Kupffer cells in livers of developing mice.

Background: Kupffer cells are well known macrophages of the liver, however, the developmental characteristics of Kupffer cells in mice are not well understood. To clarify this matter, the characteristics of Kupffer macrophages in normal developing mouse liver were studied using light microscopy and immunocytochemistry.

Methods: Sections of liver tissue from early postnatal mice were prepared using immunocytochemical techniques.

Binding patterns of peptide-containing liposomes in liver and spleen of developing mice: comparison with heparan sulfate immunoreactivity.

Background: Liposomes incorporating peptide from the Plasmodium circumsporozoite protein (CSP) accumulate rapidly and selectively in adult mouse liver.

Purpose: The development of the liposome-binding pattern in liver and spleen was studied in relationship to the development of extracellular matrix molecules.

Methods: Liposomes were administered to mice intravascularly or applied to the surface of liver and spleen slices in vitro.

Liposomal delivery of doxorubicin to hepatocytes in vivo by targeting heparan sulfate.

Previous work demonstrated that liposomes, containing an amino acid sequence that binds to hepatic heparan sulfate glycosaminoglycan, show effective targeting to liver hepatocytes. These liposomes were tested to determine whether they can deliver doxorubicin selectively to liver and hepatocytes in vivo. Fluid-phase liposomes contained a lipid-anchored 19-amino acid glycosaminoglycan targeting peptide.

Cellular organization of normal mouse liver: a histological, quantitative immunocytochemical, and fine structural analysis.

The cellular organization of normal mouse liver was studied using light and electron microscopy and quantitative immunocytochemical techniques. The general histological organization of the mouse liver is similar to livers of other mammalian species, with a lobular organization based on the distributions of portal areas and central venules. The parenchymal hepatocytes were detected with immunocytochemical techniques to recognize albumin or biotin containing cells.

Liposomal polyethyleneglycol and polyethyleneglycol-peptide combinations for active targeting to liver in vivo.

This report describes the development and evaluation of a range of polyethyleneglycol and polyethyleneglycol-peptide liposome formulations that effectively target liver in vivo. A 19-amino-acid sequence from the N-terminal region of the circumsporozoite protein of Plasmodium berghei was attached to the distal end of di22:1-aminopropane-polyethyleneglycol(3400), and incorporated into liposomes containing di22:1-phosphatidylcholine and di22:1-phosphatidylethanolamine-polyethyleneglycol(5000). By systematically varying the mole fractions of both the lipid-polyethyleneglycol and the lipid-polyethyleneglycol-peptide conjugates, and screening for serum-induced aggregation in vitro, a serum-stable range of formulations was established.

Liposomes incorporating a Plasmodium amino acid sequence target heparan sulfate binding sites in liver.

Previous studies demonstrated that intravenously administered liposomes, incorporating a peptide from the Plasmodium circumsporozoite protein, accumulate rapidly and selectively in mouse liver. The present investigation was designed to determine the molecular components in liver responsible for liposome targeting. Studies of liver tissue slices demonstrated that immunoreactivity for heparan sulfate proteoglycan (HSPG), but not other tested proteoglycans, was distributed along sinusoidal borders of liver; this immunoreactivity appeared associated with nonparenchymal cells of the sinusoids and with the basolateral portion of hepatocytes.

Effective targeting of liposomes to liver and hepatocytes in vivo by incorporation of a Plasmodium amino acid sequence.

Purpose: Several species of the protozoan Plasmodium effectively target mammalian liver during the initial phase of host invasion. The purpose of this study was to demonstrate that a Plasmodium targeting amino acid sequence can be engineered into therapeutic nanoparticle delivery systems.

Methods: A 19-amino peptide from the circumsporozoite protein of Plasmodium berghei was prepared containing the conserved region I as well as a consensus heparan sulfate proteoglycan binding sequence.

Kappa opioid control of seizures produced by a virus in an animal model.

Epilepsy remains a major medical problem of unknown aetiology. Potentially, viruses can be environmental triggers for development of seizures in genetically vulnerable individuals. An estimated half of encephalitis patients experience seizures and approximately 4% develop status epilepticus.

A role for endocannabinoids in viral-induced dyskinetic and convulsive phenomena.

Dyskinesias and seizures are both medically refractory disorders for which cannabinoid-based treatments have shown early promise as primary or adjunctive therapy. Using the Borna disease (BD) virus rat, an animal model of viral encephalopathy with spontaneous hyperkinetic movements and seizure susceptibility, we identified a key role for endocannabinoids in the maintenance of a balanced tone of activity in extrapyramidal and limbic circuits. BD rats showed significant elevations of the endocannabinoid anandamide in subthalamic nucleus, a relay nucleus compromised in hyperkinetic disorders.

Patterns of afferent projections to the dentate gyrus studied in organotypic co-cultures.

Cholinergic axons originating from the septum form a characteristic layer of preterminal axons and apparent termination in the molecular layer of the hippocampal dentate gyrus. The present study explored the specificity of this characteristic axonal pattern, through the use of organotypic slice co-cultures. Slices of hippocampus were co-cultured with a slice from one of a variety of other potential sources of afferents, and the afferent axons were labeled histochemically or immunocytochemically to determine which afferents distribute within the dentate molecular layer in a pattern similar to that formed by septal cholinergic projections.

Assessment of factors regulating axon growth between the cortex and spinal cord in organotypic co-cultures: effects of age and neurotrophic factors.

Axon growth failure in the central nervous system (CNS) of adult animals is thought to be attributable to several factors, including an inadequate intrinsic growth response, the presence of inhibitory molecules, and a lack of adequate neurotrophic support. Here we use a new in vitro assay system to quantitatively assess growth of axons in cortex/spinal cord organotypic co-cultures from neonatal rats. Co-cultures of cortex and spinal cord were prepared from neonatal rats at P3 or P7, and by pairing cortex and spinal cords from different ages.

Absence of selectivity in the loss of neurons from the developing cortical subplate of the rat.

Neurons of the cortical subplate display evidence of cell death, although a significant population survives to the mature brain. The present study examined different populations of neurons to determine if the loss of cells was specific for a particular cell type. Immunocytochemical procedures for neurons expressing GluR2/3, GAD, or NPY, were used on tissue sections taken from animals at gestational day 18 to postnatal day 21.

Local proliferation of microglia cells in response to neocortical injury in vitro.

Studies examined whether increased numbers of microglia following neural damage result from induced mitotic activity of resident microglia in situ. Organotypic slice cultures of neocortex were maintained for 1 week prior to placement of lesions. Increased numbers of OX-6 or tomato lectin labeled microglial cells were detected 1-8 days following lesions.

AFGF promotes axonal growth in rat spinal cord organotypic slice co-cultures.

This study developed a slice culture model system to study axonal regeneration after spinal cord injury. This model was tested in studies of the roles of acidic fibroblast growth factor (aFGF) and peripheral nerve segments in axonal growth between pieces of spinal cord. Transverse sections of P15-P18 Sprague-Dawley rat spinal cord were collected for organotypic slice cultures.