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Results for “tissue differentiation”

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At least 271 records · Page 15Linked to original sources
PubMed1991

Differential tissue expression of the Lewis blood group antigens: enzymatic, immunohistologic, and immunochemical evidence for Lewis a and b antigen expression in Le(a-b-) individuals.

The Lewis blood group system comprises two main carbohydrate antigens, Le(a) and Le(b). Lewis typing has traditionally been based on serologic determinations using erythrocytes and saliva. Several recent studies have demonstrated that erythrocyte Lewis phenotype may change during pregnancy or disease, and inappropriate Lewis antigens have been found in both normal and neoplastic tissue. To evaluate whether these observations are in conflict with the presently proposed genetic and biosynthetic basis of the Lewis blood group system, we performed a combined enzymatic, immunohistologic, and immunochemical study of Lewis antigen expression in normal and neoplastic tissues, as well as erythrocytes, plasma, and saliva of Le(a-b-)-typed individuals. Of six cancer-bearing patients typed Le(a-b-), three were identified as nongenuine owing to the presence of alpha 1----4fucosyltransferase activity (alpha 1----4FT) and Lewis antigens in saliva and three were identified as genuine (lacking alpha 1----4FT and Lewis antigens in saliva). These genuine Le(a-b-) individuals were shown to express significant alpha 1----4FT in tissues, and Lewis antigens were detected in tissues by immunohistology as well as immunochemistry. We conclude that the Lewis phenotype obtained by serologic determination of erythrocytes and saliva does not apply to all tissues. We discuss biosynthetic and genetic consequences of this finding.

Colon↗
PubMed1988

Differential tissue expression and developmental regulation of guanine nucleotide binding regulatory proteins and their messenger RNAs in rat heart.

The expression and developmental regulation of the alpha and beta subunits of the guanine nucleotide binding regulatory proteins, Gi and Go, were examined in rat atria and ventricles. Protein levels were determined by quantitative immunoblot analysis using affinity purified monospecific antibodies. Northern blot and dot blot analyses were used to characterize and quantitate relative amounts of mRNA encoding these G protein subunits. The concentrations of Go alpha, Gi alpha, and beta subunit protein were found to be greater in adult atrial than in adult ventricular membranes (5.2-, 1.5-, and 2.8-fold, respectively). A corresponding 3.4-fold difference in Go alpha mRNA level was also observed, as well as a 1.3-fold difference in Gi alpha-3 mRNA level. No difference was seen between the amount of beta, Gi alpha-1, Gi alpha-2 mRNA in adult atria and adult ventricles. Comparison of neonatal and adult tissues revealed a developmental decrease in ventricular Gi alpha protein and Gi alpha-2 mRNA levels (70 and 47%, respectively). Developmental decreases were also observed in the amount of mRNA encoding beta and Go alpha in ventricles (47 and 61%, respectively), and beta and Gi alpha-2 in atria (40 and 36%, respectively), while a developmental increase in atrial Gi alpha-3 mRNA levels was observed (57%). These results demonstrate differences in the expression of G protein subunits in rat atria and ventricles, as well as regulation of the levels of these subunits during cardiac development.

Adenosine Diphosphate Ribose↗