Rectangular loop-gap resonator with the light access to the sample.

A modified rectangular loop-gap resonator for X-band electron paramagnetic resonance (EPR) studies of aqueous samples, enabling the light access, is described. Changes introduced into rectangular resonator geometry, previously presented in Piasecki et al. (1998) [1], and redesigned coupling structure lead to the better thermal and mechanical stability.

Concomitant up-regulation of astroglial high and low affinity nerve growth factor receptors in the CA1 hippocampal area following global transient cerebral ischemia in rat.

We have examined the effect of global transient cerebral ischemia, evoked in rat by 10 min of cardiac arrest, upon the changes in the cellular expression of two nerve growth factor (NGF) receptors (TrkA and p75) in the hippocampus. We have used immunocytochemical procedures, including a quantitative analysis of staining, along with some quantitative morphological analyses. We have found, under ischemic conditions, a decrease of TrkA immunoreactivity in degenerating CA1 pyramidal neurons and in neuropil.

Cellular expression of tumor necrosis factor a and its receptors in human ischemic stroke.

We evaluated by immunocytochemistry cellular localization and time-dependent expression of tumor necrosis factor a (TNF-alpha) and its receptors p55 (TNF-RI) and p75 (TNF-R2) in human ischemic brains. We observed them in microglia, neurons, astrocytes, macrophages and blood vessels. Since TNF-alpha expression was very intense and prolonged in microglia, it probably constitutes the main cellular source of the cytokine following cerebral ischemia in humans.

Long-term changes in calbindin D(28K) immunoreactivity in the rat hippocampus after cardiac arrest.

Calbindin D(28K) (CB) expression was analyzed in the rat hippocampus following 10-min-cardiac arrest-induced ischemia within a year after reperfusion. In rats examined 3 days after ischemia, CB immunoreactivity disappeared completely from CA1 pyramidal neurons and from most CA2 pyramids. In the stratum granulosum of the dentate gyrus, mossy fibers, and hippocampal interneurons, CB immunoreactivity was preserved, although staining was somewhat paler than that in control rats.

Pathomorphological variations of the AIDS-associated progressive multifocal leukoencephalopathy.

Pathological analysis of 20 cases of the progressive multifocal leukoencephalopathy (PML) appearing in the course of acquired immune deficiency syndrome (AIDS) is presented. PML occurred in 10% of all AIDS cases, collected in the period from 1987 to 1999. PML appeared either as the only brain pathology or accompanied HIV-related brain alterations isolated or concomitant with one or several opportunistic infections and/or neoplastic growth (malignant lymphoma).

Pattern of neuronal loss in the rat hippocampus following experimental cardiac arrest-induced ischemia.

The pattern of neuronal loss in the rat hippocampus following 10-min-long cardiac arrest-induced global ischemia was analyzed using the unbiased, dissector morphometric technique and hierarchical sampling. On the third day after ischemia, the pyramidal layer of sector CA1 demonstrated significant (27%) neuronal loss (P<0.05).

Prolonged and concomitant induction of astroglial immunoreactivity of interleukin-1beta and interleukin-6 in the rat hippocampus after transient global ischemia.

We have investigated the pattern of expression of IL-1beta and IL-6 immunoreactivities in rat hippocampus after transient complete brain ischemia evoked by a 10 min cardiac arrest, at survival times ranging from 1 day to 28 days. To identify the cell types expressing the two immunoreactivities we used specific cell markers and combined staining procedures. In the intact brain IL-1beta and IL-6 were mainly localized in neurons particularly in pyramidal and granular cell layers.

Immunoultrastructural expression of intercellular adhesion molecule-1 in endothelial cell vesiculotubular structures and vesiculovacuolar organelles in blood-brain barrier development and injury.

Blood vessels from the vasculature of mouse brains during postnatal development and from human brain tumors (hemangiomas) removed at biopsy were examined immunocytochemically by transmission electron microscopy (TEM) or high-voltage transmission electron microscopy (HVEM) to determine the expression of intercellular adhesion molecule-1 (ICAM-1). In the mouse brains, ICAM-1 was shown to be initially expressed on the luminal and abluminal endothelial cell (EC) surfaces on day 3 after birth. ICAM-1 intensity increased on the luminal EC surfaces and labeled vesiculotubular profiles (VTS, defined in the present report) between days 5 and 7.

Opportunistic infections of the central nervous system in the course of acquired immune deficiency syndrome (AIDS). Morphological analysis of 172 cases.

A neuropathological analysis of 172 cases of AIDS in adults was carried out, to determine the occurrence and nature of the opportunistic infections of the central nervous system (CNS). The material comprised 155 cases of men, and 17 women. Mean age of patients was 38 years.

Cerebral accumulation of beta-amyloid following ischemic brain injury with long-term survival.

Deposits that are recognized by antibodies specific for the C-terminal and beta-amyloid peptide (beta A) but not the N-terminal sequences of the amyloid precursor protein (APP) fragments are present in the extra- and intracellular space in ischemic rat brain with 1 year survival. The immunohistochemical profile indicates that the APP in these deposits is truncated between the N-terminal and beta A and terminates at the C-terminal. This process probably is reaching into the extracellular space.

Cerebral lymphomas in AIDS. Neuropathological study.

A morphological analysis was done of 15 cases of malignant cerebral lymphomas selected from the material of 160 brains of patients, who died in the course of full-blown acquired immune deficiency syndrome (AIDS) during the period of 1987-1997. Cases with cerebral lymphomas comprised 9.4% of the whole collection.

Endothelial nitric oxide synthase in vascular endothelium of rat hippocampus after ischemia: evidence and significance.

Electron microscopy immunocytochemical study was performed to clarify ultrastructural localization and role of endothelial nitric oxide synthase (EC-NOS) in the endothelial cells (EC) of rat hippocampal vessels after transient cerebral ischemia. EC-NOS immunoreactivity was found in the endothelial cells in association with plasma membrane, sub-plasmalemmal vesicles, basal membrane and in cytosol (cytoplasm free of subcellular organelles). A sharp transient increase in immunoreactivity of NOS was observed at 10 min up to 1 hour after ischemia.

Ultrastructural studies of PECAM-1/CD31 expression in the developing mouse blood-brain barrier with the application of a pre-embedding technique.

The aim of this study was to investigate the time of expression of the adhesion molecule platelet endothelial cell adhesion molecule-1 (PECAM-1/CD31) in the developing mouse blood-brain barrier (BBB). Ultrastructural studies employing a preembedding technique described herein demonstrate that PECAM-1 is initially expressed on the luminal and abluminal endothelial cell surfaces in the newborn animals. This adhesion molecule expression appears to increase in intensity at 7-10 days post partum and then decreases to a weak labelling of the luminal endothelial cell surfaces at two weeks after birth.

Neuropathological syndromes in the course of full blown acquired immune deficiency syndrome (AIDS) in adults in Poland (1987-1995).

Morphological analysis of the brains from 100 cases of full blown AIDS patients observed in the course of 1987-1995 years was performed. The material comprised 96 males, 3 females and 1 infant, 11 months old. Early material consisted almost exclusively of homo- and bisexuals, while in the last years heterosexual drug addicts prevailed.

Endothelin-like immunoreactivity in hippocampus following transient global cerebral ischemia. II. The blood-brain interphase.

The effect of transient, global cerebral ischemia on the distribution of endothelin (ET) in blood-brain barrier (BBB) in CA1 area of hippocampus long-time after ischemia was estimated using post-embedding immunogold technique. ET-like immunoreactivity as a gold particles was localized in all compartments of the blood-brain barrier e.g.

2-chloro- and 2-bromo-2'-deoxyadenosine have no effect on the morphology of rat neural and glial cells in organotypic culture.

Organotypic cultures of hippocampus and cerebellum, established from brains of 1-3 days old rats, were exposed at different stages of development (3, 14 and 21 DIV) to 2-chloro-2'-deoxyadenosine (cladribine, 2-CdA) and 2-bromo-2'-deoxyadenosine (2-BdA) at concentrations up to 10 microM, for up to 10 days. Normal pattern and dynamics of differentiation and maturation of both neurons and glial cells was found with the use of light and electron microscopy. No ultrastructural abnormalities were induced by the substances tested.

Mitochondrial damage following exposure of organotypic cultures of human malignant gliomas to 2-chloro- and 2-bromo-2'-deoxyadenosine.

The effects of 2-chloro-2'-deoxyadenosine (cladribine, 2-CdA) and a closely related compound 2-bromo-2'-deoxyadenosine (2-BdA) on organotypic cultures of human malignant gliomas were studied with the use of electron microscopy. The cultures grown from surgical biopsies included six glioblastomas, three anaplastic astrocytomas and low-grade fibrillary astrocytoma. After 6 to 10 days of the in vitro growth the cultures were exposed to 0.

Intercellular adhesion molecule-1 (ICAM-1) upregulation in human brain tumors as an expression of increased blood-brain barrier permeability.

The distribution of intercellular adhesion molecule (ICAM-1) binding sites was studied in the microvasculature of several types of human brain tumor biopsies (angioma, glioblastoma multiforme and meningioma). Immunoelectron microscopy was performed with the application of immuno-HRP or -gold probes using a pre-embedding technique. Ultrastructural analysis demonstrated a pronounced ICAM-1 upregulation on the luminal EC and/or perivascular surfaces.

Upregulation of bax protein levels in neurons following cerebral ischemia.

The patterns of expression of the bcl-2, bax, and bci-X genes were examined immunohistochemically in neurons of the adult rat brain before and after 10 min of global ischemia induced by transient cardiac arrest. High levels of the cell death promoting protein Bax and concomitant low levels of the apoptosis-blocking protein Bcl-2 were found in some populations of neurons that are particularly sensitive to cell death induced by transient global ischemia, such as the CA1 sector of the hippocampus and the Purkinje cells of the cerebellum. Moreover, within 0.

Complete cerebral ischemia with short-term survival in rat induced by cardiac arrest. II. Extracellular and intracellular accumulation of apolipoproteins E and J in the brain.

The distribution of apolipoprotein E (apo E) and apolipoprotein J (apo J) was investigated immunocytochemically in rats at various time intervals after 10 min global cerebral ischemia (GCI) induced by cardiac arrest. Strong apo E and weaker apo J immunoreactivity was found extracellularly in multiple deposits located close to the microvessels. These deposits appeared 3 h after GCI and were present, but not in all the animals, at all time intervals studied post-GCL.

DNA protein flow cytometry of dissociated cultures of human anaplastic gliomas. Pattern of proliferation and differentiation, and the effect of a new cytostatic drug cladribine (2-CdA).

A technique of protein-DNA flow cytometry was applied to characterize cell cycling, and to assess the cytotoxicity of cladribine (2-chloro-2'deoxyadenosine) toward seven dissociated cultures of human primary brain tumors (anaplastic astrocytoma and glioblastoma multiforme) grown in vitro from surgical biopsies. Control cytograms were suggestive of that a clonogeneic fraction of the cell population consists mainly of cells with low protein content, which do not require increase in protein content before entering the S phase of the cell cycle. Following 24 or 48 hours exposure to cladribine, 1 nM approximately 1 microM, no cytotoxic effect was evident in 4 cultures, whereas in two cases dose-dependent progressive block of the phase of the cell cycle was noted.

Localization of endothelin in the blood-brain interphase in rat hippocampus after global cerebral ischemia.

Electron microscopic immunocytochemical evaluation of localization and distribution of endothelins 1, 2 and 3 in the CA1 hippocampal sector in rats submitted to 10 min global cerebral ischemia was performed. The studies were done in different postischemic periods (10 min, 3, 6, 12 and 24 h) with postembedding immuno-gold technique for electron microscopy. Endothelin-like immunoreactivity was found in endothelial cells of hippocampal microvessels and in astrocytes, microglia, macrophages and in some axonal endings.