Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.23 (beta-galactosidase)
 14,648 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Histochemical study of the visceral yolk-sac endoderm of the rat was performed in vitro (whole-embryo culture for 24, 48 and 72 h explanted at 9.5 days of gestation) and in vivo (10.5, 11.5 and 12.5 days of gestation) in order to compare the distribution and activity of various enzymes involved in the digestion and energy metabolism in both systems. It was shown that, both in vitro and in vivo gamma-glytamyltransferase and dipeptidylpeptidase IV are demonstrable in the apical cell membranes (membrane-bound hydrolases), while acid phosphatase, dipeptidylpeptidases I, II and acid beta-galactosidase are concentrated in the supranuclear vacuoles (lysosomal hydrolases), and cytoplasmic lactate dehydrogenase and mitochondrial enzymes (succinate dehydrogenase, NAD-dependent isocitrate dehydrogenase, cytochrom oxidase) are localized in the whole cytoplasm and mainly in the apical cytoplasm, respectively, of the visceral yolk-sac epithelium. In vivo, the activity of all enzymes increased until 12.5 days, but in vitro, this activity increased only until 48 h after the start of culture (corresponding to 11.5 days in vivo). Comparison of the yolk sacs at 10.5 and 11.5 days in vivo with those after 24 and 48 h in vitro showed that the activities of all the investigated enzymes were almost identical. Yolk sacs which were cultured for 72 h showed lower activities of lysosomal and mitochondrial enzymes than those at 12.5 days in vivo. It is concluded that the digestive function and energy metabolism of the visceral yolk-sac epithelium are almost identical in vitro and in vivo at 10.5 and 11.5 days.
 ...
PMID:Comparative enzyme histochemical study on the visceral yolk sac endoderm in the rat in vivo and in vitro. 651 92

Peptides of melanosomal proteins have recently been shown to be recognized in an HLA-restricted mode by specific cytolytic T lymphocytes in melanoma patients. Dendritic antigen-presenting cells (DC) are considered to be the most effective stimulators of T cell responses, and the use of these cells has therefore been proposed to generate therapeutic responses to tumor antigens in cancer patients. We, therefore, generated DC from peripheral blood of normal donors in the presence of granulocyte/macrophage colony-stimulating factor and interleukin-4. Flow cytometric analysis of the cells during a 2-week culture revealed a loss of CD14 and CD34 expression, a concomittent increase of CD1a, CD11a,b and c, CD44, CD45, CD54, HLA-class I and II, and intermediate levels of CD26, CD80 and CD86. Cultured DC stimulated proliferation of allogeneic T cells and induced a marked, up to 20-fold, stimulation of T cell proliferation after pulsing with tetanus toxoid. To achieve independence of already-identified antigenic peptides presented in HLA class I-restricted fashion, which limits the general applicability of such peptides for vaccination of melanoma patients, we tested whether DC are transfectable with eukaryotic expression plasmids. DC transfected with two reporter genes (CAT, beta-galactosidase) using a liposome-based transfection technique, exhibited only low levels of enzymatically active proteins, but were able to degrade rapidly intracellular proteins and to process peptides efficiently. Chloramphenicol acetyltransferase as well as tyrosinase mRNA were detectable after transfection by reverse-transcriptase-polymerase chain reaction, and enzyme activities became measurable. Furthermore, DC transfected with the tyrosinase gene were able to induce specific T cell activation in vitro, indicating appropriate peptide processing and presentation in DC after transfection. These data suggest new approaches to future tumor vaccination strategies.
 ...
PMID:Dendritic cells generated from peripheral blood transfected with human tyrosinase induce specific T cell activation. 748 49

The distributions of the lysosomal enzymes [acid phosphatase (AP), N-acetyl-beta-D-glucosaminidase (NAG), beta-glucuronidase (beta-Gluc), beta-galactosidase (beta-Gal), dipeptidylpeptidase II (DPP II)] and of the membrane-bound proteases [aminopeptidase M (APM), aminopeptidase A (APA), gamma-glutamyltransferase (GGT), dipeptidylpeptidase IV (DPP IV)] were investigated in the normal human adult and foetal anterior segment by histochemical methods. The distribution of these hydrolases varied between ocular tissues. The most active enzymes in the adult corneal epithelium and endothelium were AP, beta-Gluc, NAG, beta-Gal and GGT; in the keratocytes, APM, APA, beta-Gluc and GGT predominated. The adult trabecular meshwork cells were stained by AP, beta-Gluc, NAG, APM, GGT, DPP II and DPP IV. The enzymes AP, beta-Gluc, APM and APA, however, displayed greater activity in the endothelium of Schlemm's canal. The adult ciliary epithelium stained strongly for all lysosomal hydrolases; GGT was the most active protease here. Differences in enzyme activity were noted in some tissues when foetal and adult anterior segments were compared. There appeared to be a decrease in the activity of some enzymes with age and post-mortem delay greater than 24 h. The function(s) of each enzyme and their possible roles in the respective tissues are discussed.
 ...
PMID:Histochemical survey of the anterior segment of the normal human foetal and adult eye. 822 58