Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: EC:3.2.1.23 (beta-galactosidase)
14,648 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Infection of Escherichia cooi with T1, T2r+, T3 and T4 phages leads to an immediate inhibition of beta-galactosidase synthesis. Similar results were obtained with the virulent mutant of phage lambda. The degree of inhibition of beta-galactosidase synthesis depends on the time delay between the addition of the inducer and the phage particles, and on the amount of phage DNA, which has penetrated into the host cell. RNA phage MS2 exhibited no inhibitory effect on enzyme synthesis.
...
PMID:Inhibition of beta-galactosidase synthesis in Escherichia coli after infection with different DNA and RNA phages. 32 56

We are interested in using retroviral vectors to trace cell lineage and to introduce exogenous genes in chicken skin explant cultures. Here the LZ10 virus carrying the gene encoding beta-galactosidase was introduced to the skin explants by two different means: a) the virus was added to the media or b) the virus was microinjected into regions of the developing feather buds. Infection by microinjection led to localized expression of beta-galactosidase in the developing feather bud, while, surprisingly, infection by adding the virus to the culture media led to localized band of beta-galactosidase expression in the middle of the feather filament. The significance of this finding in skin morphogenesis and as a tool for experimental embryology is discussed.
...
PMID:Replication-defective virus infection of feather buds produces a localized region of beta-galactosidase activity. 132 81

To investigate a possible role of cytokines in parvovirus-mediated suppression of tumorigenesis, we tested in cell culture whether parvoviruses are able to induce interferon (IFN)-beta, tumor necrosis factor (TNF)-alpha or interleukin-6 (IL-6). Infection of rodent or human cells with the parvoviruses minute virus of mice (MVM), H-1 or adeno-associated virus (AAV) types 2 or 5 failed to induce expression of the luciferase or beta-galactosidase reporter genes transfected into these cells as constructs containing an IFN-beta promoter. Parvoviruses did weakly induce synthesis of TNF-alpha and of IL-6 in cell culture and could slightly enhance synthesis of these cytokines when induced by other agents. These in vitro data suggest that the rather unspecific tumor-suppressive properties of parvoviruses are unlikely to be attributable to stimulation of the synthesis of IFN, TNF or IL-6.
...
PMID:Parvoviruses are inefficient in inducing interferon-beta, tumor necrosis factor-alpha, or interleukin-6 in mammalian cells. 152 25

Among the potential uses of defective herpes simplex virus (HSV-1) vectors are to study neuronal physiology, neuronal gene regulation, and to perform gene therapy of neuronal diseases. The prototype HSV-1 vector, pHSVlac, stably expresses Escherichia coli beta-galactosidase from the HSV-1 immediate early (IE) 4/5 promoter in cultured rat peripheral and CNS neurons, and in neurons in the adult rat brain. The LacZ gene and the IE 4/5 promoter in pHSVlac can be replaced with genes which affect neuronal physiology or cellular promoters, respectively. A system is required to characterize these HSV-1 vectors; cultured neurons, a mixture of different kinds of neurons and glia, cannot be used. In contrast, neural cell lines represent a homogenous population of neural cells available in virtually unlimited quantities. A system, using neural cell lines, to characterize HSV-1 vectors carrying other genes or promoters is now reported: First, 4 assays are described to detect HSV-1 vector DNA, RNA transcribed from the vector, and to quantitate beta-galactosidase expression. Second, 8 cell lines derived from rodents, primates, and humans were infected with pHSVlac virus and shown to express beta-galactosidase. The cell lines tested included adrenergic and cholinergic mouse neuroblastoma cells, rat pheochromocytoma cells, rodent pituicytes, and human neuroblastoma cells. Infection of these cell lines should prove useful for characterizing HSV-1 vectors with molecular and biochemical assays. Third, differentiated rat pheochromocytoma and mouse neuroblastoma cells, which resemble neurons, were infected with pHSVlac virus and shown to stably express beta-galactosidase. Infection of these cells should be useful for determining the effect of various HSV-1 vectors on neuronal physiology. Thus, HSV-1 vectors containing various genes or promoters can be characterized using the system described in this study.
...
PMID:A system, using neural cell lines, to characterize HSV-1 vectors containing genes which affect neuronal physiology, or neuronal promoters. 164 53

Several neurological diseases which affect the corpus striatum are candidates for gene therapy. We have developed a defective Herpes Simplex Virus (HSV-1) vector system to introduce genes into postmitotic cells, such as neurons. The prototype vector, pHSVlac, contains a transcription unit which places the E. coli Lac Z gene under the control of the HSV-1 immediate early (IE) 4/5 promoter, a constitutive promoter. We now demonstrate that a HSV-1 vector can deliver a gene into striatal neurons. Infection of cultured rat striatal neurons with pHSVlac virus resulted in stable expression of beta-galactosidase for at least two weeks, without cell death. The potential to replace the Lac Z gene with other genes of interest, such as the gene responsible for Huntington's Disease, once it is isolated, may lead to insights about the pathogenesis of this genetic neurodegenerative disease, and may provide a method for performing gene therapy on this disease. Similarly, introduction of the tyrosine hydroxylase gene, which encodes the rate-limiting enzyme in the conversion of tyrosine to dopamine, into striatal neurons might provide a novel gene therapy approach towards treating Parkinson's Disease.
...
PMID:Infection of cultured striatal neurons with a defective HSV-1 vector: implications for gene therapy. 166 13

Full-length (72K) and truncated (61K) CryIVD mosquitocidal proteins of Bacillus thuringiensis (Bt) were expressed in Spodoptera frugiperda cells and larvae of Trichoplusia ni using a baculovirus vector to investigate the role of CryIVD peptides in toxicity as well as to evaluate further the baculovirus/lepidopteran system for expressing Bt proteins. The cryIVD genes were inserted into the Autographa californica multinucleocapsid nuclear polyhedrosis virus (AcMNPV) under control of the polyhedrin promoter by recombination in S. frugiperda cells between a transfer vector carrying the Bt genes and vDA26Z, a recombinant AcMNPV carrying the Escherichia coli beta-galactosidase gene under control of the DA26 promoter. Recombinant AcMNPVs carrying the genes were detected as blue occlusion body-negative plaques in monolayers of S. frugiperda cells grown in the presence of X-Gal. Infection of S. frugiperda cells and T. ni larvae with plaque-purified recombinant virus, expressing either the full-length or truncated CryIVD protein, resulted in the synthesis of proteins of the expected size, as confirmed by immunoblot analyses, and their crystallization into cuboidal inclusions in the cytoplasm. Infected cells and purified inclusions from the virus (AcCryIVD) expressing the full-length protein were highly toxic to mosquito larvae, but similar preparations from the virus (AcCryIVD-C) expressing the truncated protein with a 9.6K deletion at the N terminus were non-toxic. Proteolysis with trypsin of CryIVD proteins produced by Bt and the recombinant AcMNPVs yielded peptides corresponding in size, showing that synthesis of mosquitocidal Bt proteins in lepidopteran cells occurred. The lack of toxicity of the truncated CryIVD protein, which like the toxic full-length protein yielded a 34K protein on proteolysis that has been implicated in toxicity, indicates that by itself this protein is non-toxic. These results demonstrate the utility of the baculovirus system for expression of mosquitocidal Bt proteins and for investigation of their mode of action.
...
PMID:Synthesis and toxicity of full-length and truncated bacterial CryIVD mosquitocidal proteins expressed in lepidopteran cells using a baculovirus vector. 173 Sep 44

Primary cultures of epithelial cells from adult rat tracheas were maintained in vitro on collagen matrices and were exposed to a murine retrovirus vector expressing the E. coli beta-galactosidase gene. Infection was carried out on cells grown as monolayers under medium and on cells grown on raised platforms. Cells maintained at an air-medium interface were highly susceptible to infection with the vector, showing an efficiency of infection of 20-25%, compared with an efficiency of less than 1% for cells grown under medium. Infected beta-galactosidase-expressing cells were seeded into denuded tracheas and were capable of partially repopulating the denuded tracheas grafted subcutaneously into host rats. The susceptibility of these cells to retroviral infection suggests an approach to the treatment of some pulmonary genetic disorders such as cystic fibrosis.
...
PMID:Gene transfer into rat airway epithelial cells using retroviral vectors. 184 20

Rat pheochromocytoma PC12 cells have been modified genetically by the use of replication-defective retroviral vectors containing either the bacterial gene for beta-galactosidase (lac Z) or cDNAs for mouse beta-nerve growth factor (NGF) and the bacterial gene for neomycin resistance. Using the lac Z vector, clonal lines of PC12 cells were obtained in which almost 100% of cells stably expressed this histochemical marker. Infection of PC12 cells or the derived subclone PC12-BAG, which expresses beta-galactosidase, with the NGF vectors resulted in autocrine differentiation as assessed by extensive neurite formation, which occurred within hours after infection and was maintained for weeks in culture. Neurite formation could be partially blocked by antibodies to NGF. The percentage of cells expressing neurite outgrowth was greater than that of PC12 cells treated with exogenous NGF. PC12 cells infected with the NGF vectors were shown to release this trophic factor into the medium using a two-site enzyme immunoassay and a bioassay on 'naive' PC12 cells. PC12 cells genetically modified using these vectors provide a means to: follow the fate of the cells after transplantation into animals; test for delivery in vivo of NGF and catecholamines by grafted, autocrine-differentiated PC12 cells; and study the long-term actions of NGF on responsive cells without adding exogenous NGF.
...
PMID:Autocrine differentiation of PC12 cells mediated by retroviral vectors. 210 98

A quantitative bioassay for human immunodeficiency viruses has been developed on the basis of the ability of the tat gene to transactivate the expression of an integrated beta-galactosidase gene in a HeLa-CD4+ cell line. Infection by a single virion of HIV-1 or HIV-2 corresponds to a unique blue syncytium or a cell cluster detected after fixation and addition of 5-bromo-4-chloro-3-indolyl-beta-D-galactopyranoside (a beta-galactosidase substrate). The number of infected lymphoid cells in a culture (stimulated human peripheral blood lymphocytes and cell lines) can also be quantified by cell-to-cell transmission of HIV into the HeLa-CD4(+)-beta-galactosidase monolayer. Infections by simian immunodeficiency viruses are similarly detected. This assay has been used to determine the dose response of drugs, the half-life of HIV at 37 degrees C, and the appearance of infectious particles after virus infection.
...
PMID:Activation of a beta-galactosidase recombinant provirus: application to titration of human immunodeficiency virus (HIV) and HIV-infected cells. 211 May 96

We have developed a defective herpes simplex virus (HSV) vector system that permits the introduction of virtually any gene into mammalian central nervous system neurons. The prototype vector, pHSVlac, contains a transcription unit that places the Escherichia coli lacZ gene under the control of the HSV-1 immediate early 4/5 promoter. pHSVlac was propagated using the HSV-1 temperature-sensitive mutant ts K as helper virus. Infection of rat neurons in primary culture derived from various regions throughout the central nervous system, including spinal cord, cerebellum, thalamus, basal ganglia, hippocampus, occipital cortex, temporal cortex, and frontal cortex, resulted in stable expression of high levels of beta-galactosidase for at least 2 weeks, without cell damage. Since other genes can be expressed from pHSVlac, HSV-1 vectors may prove useful for delivery of genes into central nervous system neurons for studies on nervous system physiology or to perform gene therapy for neurological conditions.
...
PMID:Infection of cultured central nervous system neurons with a defective herpes simplex virus 1 vector results in stable expression of Escherichia coli beta-galactosidase. 215 70


1 2 3 4 5 6 7 8 9 10 Next >>

---