Expression of the CD44 receptor in the blood vessel system: an experimental study in rat

The CD44 receptor is a transmembrane glycoprotein expressed on a variety of cells like endothelial, epithelial and smooth muscle cells. This molecule has many important functions, e.g. in cell-cell and cell-matrix interactions and signal transduction. The main ligand for CD44 is hyaluronan (HYA). HYA is a glycosaminoglycan with structural and cell biological properties. The localization of HYA in the vessel wall of arteries and veins in the healthy adult and newborn rat has been described earlier. In this study the occurrence of the CD44 receptor was investigated in the same vessels and compared to the localization of HYA. Both CD44 and its ligand showed an increased expression in the vessel wall of newborn rats compared to that of adult rats. Although HYA is abundant in the adventitia of adult rats, virtually no expression of CD44 was observed. Our results indicate that the CD44 receptor expression is increased during the stage of maturation of the vessel tree whereas the CD44 receptor is less needed by HYA in the healthy vessel wall.     

Blood Lymphocyte Proliferation Response to Pollen Extract as a Monitor of Immunotherapy

In a study of immunotherapy 41 children with seasonal rhinoconjunctivitis due to deciduous tree pollen allergy were monitored by means of symptom scoring, patient self-evaluation, conjunctival provocation tests and lymphocyte proliferation in vitro to the allergen. The lymphocyte responsiveness to birch pollen decreased significantly during the first year of immunotherapy. However, neither the lymphocyte responsiveness before treatment nor changes in lymphocyte reactivity during the immunotherapy correlated with the clinical efficacy of the therapy as evaluated by changes in symptom scores, self-evaluation or conjunctival provocation test changes in the individual patients. The results indicate the lymphocyte responsiveness to an allergen cannot be used to select patients for immunotherapy, i.e. to predict whether a patient would benefit from immunotherapy or not, or to evaluate the effects of immunotherapy after beginning the treatment. However, lymphocyte proliferation response to an allergen indicates clinical sensitivity.     

Effects of lithium on water intake and renal concentrating ability in rats with vasopressin-deficient diabetes insipidus (Brattleboro strain)

Male and female Long Evan rats and Brattleboro rats with ADH-deficient diabetes insipidus were treated with lithium administered in the diet for 12 weeks. The plasma lithium level was about 1 mmol/l in all groups. Lithium caused polydipsia and polyuria and lowering of renal concentrating ability in normal rats. In rats with ADH deficiency lithium tended to increase water intake, but did not influence spontaneous urine osmolality or maximal urine osmolality during water deprivation. The results indicate that the renal concentrating defect caused by lithium in rats can be explained by ADH-blockade as the only mechanism. However, there is circumstantial evidence that lithium in addition may stimulate thirst mechanisms by an ADH-independent action.     

Trophic effect of the sympathetic nervous system on the early development of the rat parotid gland: A quantitative ultrastructural study

Rats were sympathetically denervated on one side by avulsion of the superior cervical ganglion either immediately after birth (within 4 hr) or when the salivary glands were fully developed. Nine weeks after ganglionectomy the parotid glands were subjected to microscopical studies. As shown by the lack of specific fluorescence, sympathetic denervation caused an almost total depletion of catecholamines in the acini. This was further substantiated at the electron microscopic level using KMnO⁴ as fixative. No alterations in either gland weight or in acinar cell size were noticeable after adult sympathectomy. On the other hand, neonatal denervation caused a decrease in gland weight as well as acinar cell hypotrophy. The mean volume of individual acinar cells was reduced by roughly 25% and the granule volume density by about 50%. Also the mean volume of individual granules was decreased. These findings indicate an important role for the sympathetic nerve system in the maturation of the rat parotid gland.     

Studies on the Histamine Releasing Effect of Bee Venom Fractions and Compound 48/80 on Skin and Lung Tissue of the Rat

Two bee venom fractions, F I and F II, obtained by gel filtration, and compound 48/80, were shown to release histamine from skin and lung tissue of the rat. F I is the phosphatidase A containing fraction, and F II contains a basic polypeptide. Dose-response relationships, the time course of the histamine release, and the influence of enzyme inhibitors were studied. The results with F II and compound 48/80 were similar, suggesting that the two substances activate the same kind of release mechanism. It is concluded that F II is not related to the earlier described bee venom polypeptides melittin and aparnin. The mode of action of phosphatidase A was distinctly different from that of F II or compound 48/80. The results are consistent with the assumption that it acts in a “non-specific.” way by hydrolysing tissue phosphatides to lyso compounds, which in turn damage the tissue.     

Exploring cancer register data to find risk factors for recurrence of breast cancer – application of Canonical Correlation Analysis

Background  

A common approach in exploring register data is to find relationships between outcomes and predictors by using multiple regression analysis (MRA). If there is more than one outcome variable, the analysis must then be repeated, and the results combined in some arbitrary fashion. In contrast, Canonical Correlation Analysis (CCA) has the ability to analyze multiple outcomes at the same time.     

P2 receptor mRNA expression profiles in human lymphocytes,monocytes and CD34+ stem and progenitor cells

Background  

Extracellular nucleotides (ATP, ADP, UTP and UDP) exert a wide range of biological effects in blood cells mediated by multiple ionotropic P2X receptors and G protein-coupled P2Y receptors. Although pharmacological experiments have suggested the presence of several P2 receptor subtypes on monocytes and lymphocytes, some results are contradictory. Few physiological functions have been firmly established to a specific receptor subtype, partly because of a lack of truly selective agonists and antagonists. This stimulated us to investigate the expression of P2X and P2Y receptors in human lymphocytes and monocytes with a newly established quantitative mRNA assay for P2 receptors. In addition, we describe for the first time the expression of P2 receptors in CD34⁺ stem and progenitor cells implicating a potential role of P2 receptors in hematopoietic lineage and progenitor/stem cell function.     

Catechol-O-methyltransferase activity in erythrocytes in Down''s syndrome: family studies

Catechol-O-methyltransferase (COMT) activity in erythrocytes was measured in six children with Down's syndrome and in their parents to determine if COMT activity is related to a gene on chromosome 21. A gene dosage effect was a possible explanation of the COMT value in three of the children but not in the other three.     

Characterization of cell lines derived from hamster tumors induced with the BK virus

Summary Some of the properties of three continuous cell lines derived from BK virus-induced hamster tumors were examined. The cell lines hadin vitro growth characteristics of transformed cells. Morphologically most of the cells were fibroblastic, but multinucleated giant cells were also common. Ultrastructurally all three cell lines displayed the usual features of cells grownin vitro. Marked variation in the nuclear size and shape as well as prominent nucleoli were characteristic to these cells. No viruses or virus-like particles were found. Virus isolation attempts by fusing the cells with Vero cells were negative, and no virion antigen was detected in these cells by immunofluorescence. T antigen similar to that of other papovaviruses was found in the cells. This antigen stained with sera from a number of hamsters carrying transplanted BK virus-induced tumors, and also with SV 40 T antisera. The antigen disappeared after 30 minutes at 56° C. Cytogenetic analyses showed that the three cell lines were heteroploid with subtetraploid numbers of chromosomes. Chromosome abnormalities were also seen. All three cell lines induced sarcomatous tumors in adult hamsters after subcutaneous inoculation.With 4 Figures