Blood vessels in epiphyseal cartilage of human fetal femoral bone: a scanning electron microscopic study of corrosion casts

Formation of intrachondral vessels (cartilage canals) in the proximal femoral epiphysis was studied in 13- to 22-week-old human fetuses using a corrosion casting technique and scanning electron microscopy. Several successive morphological stages of angiogenesis occurring inside the hyaline cartilage were distinguished. The process of cartilage vascularization starts with the formation of hairpin loops sent off from the perichondrial vascular network into the adjacent cartilage. A capillary glomerulus is then formed at the leading end, and the entire vascular unit grows in length, assuming a mushroom-like shape. Its further elongation is accompanied by a backward expansion of the capillary network which surrounds a pair of main vessels (arteriole and venule) like a manchette. The subsequent branching of such primary vascular units proceeds according to the same morphological patterns. The resulting tree-like vascular formations become interconnected via their lateral branches. This study clearly supports the invasion theory of cartilage canal formation.     

Guinea-pig peritoneal macrophage receptor for IgG--II. Purification of the receptor and its partial characterization

The Fc gamma receptor of guinea-pig peritoneal macrophages was purified by affinity chromatography by using rabbit IgG or guinea-pig IgG2 coupled to Sepharose. Lysates prepared by treatment of 125I-labeled macrophages with NP-40 were first applied to BSA-Sepharose and then to IgG-Sepharose and eluted with 0.5 M acetic acid containing 1% NP-40. The specific binding was determined by interaction of the 125I-labeled receptor with IgG-Sepharose in the presence and absence of soluble IgG. The specific binding of the purified receptor was 42-82%. Interactions of the purified receptor with IgG-Sepharose were equally well inhibited by soluble rabbit IgG or guinea-pig IgG2, but not by F(ab')2 fragments. Inclusion of NP-40 in the buffer used in the assay reduced nonspecific binding of the receptor to the affinity gels. The purified receptor can be stored for 20 days at 4 degrees C without a significant loss of the specific binding activity. Analysis of the receptor by SDS-polyacrylamide gel electrophoresis, under nonreducing and reducing conditions, revealed two major peaks of radioactivity corresponding to mol. wts of about 50,000 and 25,000, and one very minor peak corresponding to a mol. wt of about 30,000. The results obtained suggest that the protein of the second major peak is a product of the dissociation of the protein of the first major peak rather than a product of its reduction by 2-mercaptoethanol.     

The cGMP synthesis and PKG1 expression in murine lymphoid organs

Numerous reports indicate that cyclic 3',5' guanosine monophosphate (cGMP) is involved in the regulation of immune processes. However, the mechanisms responsible for the synthesis of this nucleotide and its signaling pathways in immune cells are still not well recognized. The aim of our studies was to establish: 1) which form of guanylyl cyclase (GC) synthesizes cGMP in murine lymphoid organs and 2) whether the same organs express the isoforms PKG1alpha and/or PKG1beta of protein kinase G, known as possible target for synthesized cGMP. Cells isolated from thymus, lymph nodes, and spleen were treated with activators (SNP, ANP, CNP, STa) of soluble or particulate cyclases. Sodium nitroprusside (SNP) elevated intracellular cGMP 2-fold in thymic and lymph node cells and about 10-fold in spleen cells. Atrial natriuretic peptide (ANP) caused modest but statistically significant increases of cGMP in cells of all three organs. Additionally, spleen cells elevated their cGMP content about 2-fold in response to C-type natriuretic protein (CNP). In cellular homogenates of the all analyzed organs, the antibody anti-PKG1beta stained the 78 kDa band corresponding to the molecular mass of PKG1. Only homogenates of spleen cells were stained by the antibody recognizing PKG1alpha. Our results indicate that in the investigated organs cGMP may be synthesized mainly by soluble GC in response to nitric oxide. The modest increase of cGMP upon stimulation by ANP suggests that in all these organs either exists only a small subpopulation of cells that express particulate cyclase GC-A or GC-A is expressed at very low level. In spleen cells, however, cyclase GC-B appears to be the more active enzyme. Elevated cGMP concentration may in turn activate PKG1beta in thymus, lymph node, and spleen cells and also PKG1alpha in spleen cells.     

Cytometric analyses to distinguish death processes

The morphological changes typical of apoptosis, as well as the loss of integrity of the plasma membrane and the breakdown of nuclear DNA provide numerous features that permit recognition of apoptotic cell death by various methods. Flow cytometry (FCM) and laser scanning cytometry (LSC) allow for accurate and rapid measurement of apoptosis in both cultures and clinical samples (e.g. solid tumors, bone marrow aspirates, peripheral blood etc.). Furthermore, both FCM and LSC enable one to correlate the apoptosis with the position of the dying cell in the cell cycle. Discussion includes the cytometric identification and quantitation of apoptotic or necrotic cells, based on the analysis of a particular biochemical or molecular feature that is characteristic for either necrosis or apoptosis.     

Changes in cognitive function after a 12-week exercise intervention in adults with Down syndrome

Background

Between 250,000 and 400,000 individuals in the United States are diagnosed with Down syndrome (DS). Nearly all adults with DS will develop Alzheimer's disease pathology starting in their thirties. Recent studies suggest that increased physical activity (PA) may be important for maintaining components of cognition, including memory.

Evaluation of selected immunological parameters in alcohol dependence syndrome

In 28 patients with alcohol dependence syndrome (ADS) the study of selected immunological parameters (percentage of peripheral blood lymphocytes CD3+, CD4+, CD8+, CD19+; lymphocyte transformation without and with phytohemagglutinin (PHA), concanavalin A (Con A), pokeweed mitogen (PWM); chemiluminescence of peripheral blood granulocytes stimulated with phorbol myristate acetate (PMA)) and Instytut Mérieux' skin tests (Multitest CMI) were performed. The results of immunological parameters were connected with activity of liver enzymes (aspartate aminotransferase (ASP), alanine aminotransferase (ALT), gamma-glutamyltransferase (GGT). The differences of reactivity of immune system in the tested groups of patients were observed.     

Immunological parameters in patients suffering from alcohol-dependence syndrome

Alcohol abuse is a major cause of abnormal liver development and activity. In addition to enzymatic malfunction, alcohol and its metabolites induce changes in the levels of some liver antigens, resulting in immunological disturbance. The purpose of the present study is to correlate the severity of liver function impairment with the length of alcohol abuse, in order to be able to use such tests as indicative of the severity of Alcohol Dependence Syndrome. Thirty-one alcohol abusers were allocated to three groups on the basis of the levels of their liver enzymes, and were tested for a variety of immunological parameters and skin reactions. The data indicate that even though not all immunological values measured differed significantly from the control values, in those that did (granulocytes, lymphocytes, CD4/CD8 ratio, C3, IgG, IgM and some skin positive reactions), the biggest difference was between the healthy volunteers and the group with the longest abuse period. It is suggested that changes in selected immunological parameters in alcohol abusers may indicate the severity of their liver dysfunction.