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

To study early events of neonatal herpes simplex virus (HSV) encephalitis and its sequelae, the authors induced a controlled infection in the brains of mice using HSVgH, a genetically modified Disabled Infective Single Cycle virus. Neonatal Balb/C mice were infected with various amounts of HSVgH- virus by intracerebral injection. Results showed that the survival of infected mice was dependent on the amount of virus injected. Infection with 200,000 plaque forming units (pfu) of HSVgH-, virus resulted in 0% survival, whereas 25,000 pfu resulted in 75% survival. If the mice died, 98% of the deaths occurred between 3 and 7 days after infection. Replication competent virus was recovered from 20% of mice brains infected with 25,000 pfu of HSVgH-. Neutralizing antibodies were not detected 6 weeks post infection in sera of mice, which survived infection with 25,000 pfu of HSVgH-. LacZ histochemistry and immunoperoxidase staining using anti-HSV and anti- beta-galactosidase antibodies revealed that the infection was limited to the site of injection. Tissue destruction was observed at the site of inoculation 3 days post infection using cresyl violet staining. At 3 days post infection adjacent sections showed positive cells for viral antigens and apoptotic cells in the infected area. Immunoperoxidase staining using antibodies to surface markers showed microglial activation beginning on day 1 and astrocyte proliferation beginning on day 3 post infection. B and T lymphocytes were not detected on day 1 through 7 post infection. This controlled experimental HSV infection suggests a limited non-specific early host response in the neonate to HSV encephalitis.
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PMID:Innate and adaptive host response during the initial phase of herpes simplex virus encephalitis in the neonatal mouse. 1706 29

Primary cultures of progenitor and immature rat Leydig cells were established from the testes of 21- and 35-d-old rats, respectively. The cell population remained homogeneous after 4-6 d in culture as judged by staining for 3beta-hydroxysteroid dehydrogenase, but the cells were unable to bind 125I-human chorionic gonadotropin (hCG) or to respond to hCG with classical LH receptor (LHR)-mediated responses, including cAMP and inositol phosphate accumulation, steroid biosynthesis, or the phosphorylation of ERK1/2. Infection of primary cultures with recombinant adenovirus coding for beta-galactosidase showed that approximately 65% of the cells are infected. Infection with adenovirus coding for the human LHR (hLHR) allowed for expression of the hLHR at a density of approximately 25,000 receptors per cell and allowed the cells to respond to hCG with increases in cAMP and inositol phosphate accumulation, steroid biosynthesis, and the phosphorylation of ERK1/2. Although progenitor and immature cells were able to respond to hCG with an increase in progesterone, only the immature cells responded with an increase in testosterone. In addition to these classical LHR-mediated responses, the primary cultures of progenitor or immature rat Leydig cells expressing the recombinant hLHR proliferated robustly when incubated with hCG, and this proliferative response was sensitive to an inhibitor of ERK1/2 phosphorylation. These studies establish a novel experimental paradigm that can be used to study the proliferative response of Leydig cells to LH/CG. We conclude that activation of the LHR-provoked Leydig cell proliferation requires activation of the ERK1/2 cascade.
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PMID:Lutropin/choriogonadotropin stimulate the proliferation of primary cultures of rat Leydig cells through a pathway that involves activation of the extracellularly regulated kinase 1/2 cascade. 1741 5

Melanopsin-expressing intrinsically photosensitive retinal ganglion cells (ipRGCs) innervate the hypothalamic suprachiasmatic nucleus (SCN) and the olivary pretectal nucleus (OPN), providing irradiance information for entrainment of circadian rhythms and for stimulating the pupillary light reflex. In this study, mice were used in which the melanopsin gene was replaced with the tau-lacZ gene. Heterozygous (tau-lacZ+/-) mice express both melanopsin and beta-galactosidase. In tau-lacZ+/- mice, only approximately 50% of melanopsin ipRGCs contain beta-galactosidase, and these cells are specifically labeled with a C-terminus melanopsin antibody. Retrograde tracer injection into the SCN labels beta-galactosidase-expressing ipRGCs (termed M1) that comprise approximately 80% of the SCN-projecting ipRGCs. M1 ipRGCs and an additional set of ipRGCs (termed M2) are labeled with a melanopsin antiserum targeted against the N-terminus of the melanopsin protein; M2 ipRGCs do not contain detectable beta-galactosidase, and these cells make up the remainder of the SCN-projecting RGCs. Tracer injection into the OPN labeled non-melanopsin RGCs and both types of melanopsin ipRGC: 45% M1 and 55% M2. Infection of the iris with pseudorabies virus (PRV) results in retrograde transneuronal label of OPN projection neurons that innervate preganglionic parasympathetic neurons of the Edinger-Westphal nucleus; PRV-labeled cells were located almost exclusively within the terminal field of M1 ipRGCs in the periphery (shell) of the OPN. The OPN core receives retinal input, and we hypothesize that the OPN core receives input from the M2 ipRGCs. Two subtypes of melanopsin ipRGCs project differentially to the SCN and OPN; the functional significance of ipRGCs subtypes is currently unknown.
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PMID:Two types of melanopsin retinal ganglion cell differentially innervate the hypothalamic suprachiasmatic nucleus and the olivary pretectal nucleus. 1837 Oct 76

Prokaryotes of the genus Mycoplasma are the smallest cellular organisms that persist as obligate extracellular parasites. Although mycoplasma infection is known to be associated with chromosomal instability and can promote malignant transformation, the mechanisms underlying these phenomena remain unknown. Since persistence of many cellular parasites requires suppression of apoptosis in host cells, we tested the effect of mycoplasma infection on the activity of the p53 and nuclear factor (NF)-kappaB pathways, major mechanisms controlling programmed cell death. To monitor the activity of p53 and NF-kappaB in mycoplasma-infected cells, we used a panel of reporter cell lines expressing the bacterial beta-galactosidase gene under the control of p53- or NF-kappaB-responsive promoters. Cells incubated with media conditioned with different species of mycoplasma showed constitutive activation of NF-kappaB and reduced activation of p53, common characteristics of the majority of human tumor cells, with M. arginini having the strongest effect among the species tested. Moreover, mycoplasma infection reduced the expression level and inducibility of an endogenous p53-responsive gene, p21(waf1), and inhibited apoptosis induced by genotoxic stress. Infection with M. arginini made rat and mouse embryo fibroblasts susceptible to transformation with oncogenic H-Ras, whereas mycoplasma-free cells underwent irreversible p53-dependent growth arrest. Mycoplasma infection was as effective as shRNA-mediated knockdown of p53 expression in making rodent fibroblasts permissive to Ras-induced transformation. These observations indicate that mycoplasma infection plays the role of a p53-suppressing oncogene that cooperates with Ras in cell transformation and suggest that the carcinogenic and mutagenic effects of mycoplasma might be due to inhibition of p53 tumor suppressor function by this common human parasite.
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PMID:Mycoplasma infection suppresses p53, activates NF-kappaB and cooperates with oncogenic Ras in rodent fibroblast transformation. 1840 66

Adenoviruses are powerful, widely utilized vectors for gene transfer. Limitations to their application, however, have not been well described. We used rat pituitary lactotrophs in primary culture as a model for studying how adenovirus vector infection modulates mitogen-induced proliferation and the activities of mitogen signaling pathways. Infection with adenovirus vectors expressing beta-galactosidase (betagal) raised basal proliferative levels and blocked fetal bovine serum (FBS)-induced proliferation of lactotrophs, but did not influence the changes in proliferation induced by forskolin, IGF-I, and bromocriptine. The betagal-expressing adenoviruses did not alter the inhibitory action of 17beta-estradiol (E(2)) in the presence of IGF-I; however, they blocked the stimulatory action of E(2) in the presence of dextran-coated charcoal-striped serum or forskolin. An adenovirus expressing no protein failed to block FBS-induced proliferation, but was effective in modulating basal proliferative levels and the stimulatory actions of E(2). The increased basal proliferative level and the blockade of FBS-induced proliferation were transient, and lost 5 days after infection while the blockade of the stimulatory action of E(2) in the presence of forskolin persisted. Adenovirus infection raised basal protein levels of the phosphorylated forms of cAMP response element-binding protein (pCREB) and ERK1/2 and increased the proportion of pCREB-immunoreactive lactotrophs. Adenoviruses also altered estrogen-induced responses in mRNA expression of several estrogen-responsive genes in a gene-specific manner. The results demonstrate that an adenovirus vector differentially interferes with lactotroph proliferation in response to various mitogens. Our results suggest that the effects of the adenovirus that are independent of the genes transferred must be considered when performing adenoviral gene transfer in the primary cultures of normal cells.
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PMID:Adenovirus vectors differentially modulate proliferation of pituitary lactotrophs in primary culture in a mitogen and infection time-dependent manner. 1857 72

The effect of the growth phase of Spodoptera frugiperda (Sf9) cells on the production of recombinant proteins (beta-galactosidase and glucocerebrosidase) was investigated. Cells infected with the recombinant Autographa californica nuclear polyhedrosis virus at the late exponential and stationary phases yielded low quantities of expressed protein. Highest enzyme yields were obtained using Sf9 cells from the early exponential phase (0.9 mg beta-galactosidase/10(6) cells and 1.7 microg glucocerebrosidase/10(6) cells). Infection of resuspension of cells collected from various phases of growth in fresh medium resulted in 75% restoration of maximal expression levels. This finding suggested either nutrient limitation or waste product accumulation as the cause of the decrease in productivity at the latter phases of growth. Further experiments revealed that the highest productivity levels could be obtained with cultures of Sf9 cells grown in a fermentor to a cell concentration of 4 x 10(6) mL(-1). The medium needed to be replaced prior to infection with the recombinant virus and supplemented with a mixture of glucose, L-glutamine, and yeastolate ultrafiltrate.
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PMID:Production of recombinant proteins in high-density insect cell cultures. 1861 84

Respiration rates in Spodoptera frugiperda (Sf-9) cell bioreactor cultures were successfully measured on-line using two methods: The O(2) uptake rate (OUR) was determined using gas phase pO(2) values imposed by a dissolved oxygen controller and the CO(2) evolution rate (CER) was measured using an infrared detector. The measurement methods were accurate, reliable, and relatively inexpensive. The CER was routinely determined in bioreactor cultures used for the production of several recombinant proteins. Simple linear relationships between viable cell densities and both OUR and CER in exponentially growing cultures were used to predict viable cell density. Respiration measurements were also used to follow the progress of baculoviral infections in Sf-9 cultures. Infection led to increases in volumetric and per-cell respiration rates. The relationships between respiration and several other culture parameters, including viable cell density, cell protein, cell volume, glucose consumption, lactate production, viral titer, and recombinant beta-galactosidase accumulation, were examined. The extent of the increase in CER following infection and the time postinfection at which maximum CER was attained were negatively correlated with the multiplicity of infection (MOI) at multiplicities below the level required to infect all the cells in a culture. Delays in the respiration peak related to the MOI employed were correlated with delays in the peak in recombinant protein accumulation. DO levels in the range 5-100% did not exert any major effects on viable cell densities, CER, or product titer in cultures infected with a baculovirus expressing recombinant beta-galactosidase.
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PMID:On-line monitoring of respiration in recombinant-baculovirus infected and uninfected insect cell bioreactor cultures. 1862 97

The rat parasite Eimeria nieschulzi is a suitable model for transfection studies and was used as an additional model organism for the genus Eimeria. We describe the transfection of this apicomplexan parasites and the cultivation of transformed stages in cell culture and in vivo. The beta-galactosidase or yellow fluorescent protein was expressed in all parasitic stages up to the second merozoite generation in vitro under control of the heterologous promoter region of Eimeria tenella mic1 gene previously described for E. tenella transfection. Pyrimethamine resistant E. nieschulzi parasites were obtained in vitro after transfection with a plasmid encoding the Toxoplasma gondii dhfr/ts-m2m3 gene. Co-transfection experiments with an YFP-plasmid resulted in pyrimethamine resistant and fluorescent parasitic stages. Infection of rats with transfected E. nieschulzi sporozoites directed to expression of beta-galactosidase or YFP in oocysts. Co-transfection with YFP/DHFR-TS allowed selection of resistant parasites in vivo. Excreted transgenic oocysts showed arrangement of YFP expression which lead to questions about meiotic recombination frequency and mechanisms.
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PMID:Reporter gene expression in cell culture stages and oocysts of Eimeria nieschulzi (Coccidia, Apicomplexa). 1879 26

The potential of spent medium to support the growth and recombinant protein production of High-Fivetrade mark cells was investigated. Growth in medium consisting of three parts fresh and one part spent medium was comparable to that in fresh medium (maximal specific growth rates of 0.028 and 0.029 h(-1), and maximal cell densities of 4 and 4.5 x 10(6) cells ml(-1), respectively). Glucose exhaustion coincided with an abrupt decrease of viability. Of 15 amino acids analyzed, not a single one was completely exhausted at the end of the growth phase. Growth in medium consisting of equal parts spent and fresh medium led to lower maximal cell concentration (2.9 x 10(6) cells ml(-1)) with a smoother death phase. Glucose supplementation at the beginning of the culture or at the end of the growth phase did not lead to an increase of either the maximal cell density or the specific growth rate. Infection of High-Fivetrade mark cells at three different densities (1.4, 2.5 and 4.2 x 10(6) cells ml(-1)) without medium change led to monotonically decreased specific productions for beta-galactosidase. Partial (75%) or total medium replacement at the higher infection density restored the specific production at the levels of the intermediate density infection (321, 292 and 389 U.(10(6) cells)(-1), respectively).
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PMID:Effect of Partial Medium Replacement on Cell Growth and Protein Production for the High-Fivetrade mark insect cell line. 1900 30

We have developed and characterized cultures of healthy and dystrophic canine myoblasts for the evaluation of various gene transfer protocols. The number of desmin-positive myoblasts was elevated (>>80%) in cultures of myoblasts obtained from different muscle territories, the diaphragm muscle giving rise to the purest cultures. Myoblasts from dogs turned out to be a very convenient source of well transfectable and transducible cells. Transfection with plasmid DNA allowed efficient transgene expression (50% of beta-galactosidase positive cells and about 375 ng luciferase/mg protein after transfection with a calcium phosphate-precipitated plasmid). Infection with high concentrations of adenoviral and retroviral vectors allowed transgene (beta-galactosidase or mini-dystrophin) detection in about 75 to 90% of the canine cells. Therefore, primary dog myoblast cultures represent a useful in vitro model for viral and non-viral gene delivery, as well as for functional evaluation and cell grafting with applications in genetic diseases, vaccination or production of circulating therapeutic proteins.
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PMID:Gene transfer into canine myoblasts. 1900 68


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