SEARCH · PubMed Health

Results for “GS”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 505 records · Page 28Linked to original sources

PubMed1988

A new cell line, GS, derived from a human renal cell carcinoma.

A new cell line, GS, of human renal cell carcinoma was established and characterized. It was derived from a metastasis of a human renal cell carcinoma, which appeared 6 years after nephrectomy. The GS cells exhibit basic characteristics of renal cell carcinoma: epithelial cell character, PAS and glycogen positivity, typical ultrastructural features. The cells have a pseudotriploid stemline with a modal number of 75 chromosomes and two marker chromosomes. GS cells formed neither colonies in soft agar nor transplantable tumours in nude mice but produced a factor(s) stimulating growth and colony forming activity of indicator cells.

Aged↗

PubMed1985

[Circulatory action and adverse effects of 3-carbethoxyamino-5-dimethylamino-acetyl-iminodibenzyl hydrochloride (Bonnecor, AWD 19-166, GS 015) in the dog and cat].

The haemodynamic and cardiac effects of GS 015, a substance of the series of the novel 5-(dialkyl-aminoacyl)-3-carbalkoxyamino-10,11-dihydro-5H-dibenz-[b ,f]-azepines with very potent antifibrillatory and antiarrhythmic actions, are studied on anaesthetized dogs and cats by means of the catheter technique. The clinical symptoms and the therapeutic range were tested on conscious animals. On the strength of the present results it can be stated that GS 015, given at pharmacodynamically effective doses, does not cause any circulatory side effects. A negative inotropic effect appears only at increased doses. Like other antiarrhythmic drugs, GS 015 possesses a limited therapeutic range which should be taken into consideration particularly in case of cardiac insufficiency. But an application seems possible also in patients during the acute stage of myocardial infarction.

Anesthesia↗

PubMed1985

[Summarized presentation of studies on the toxicology of 3-carbethoxyamino-5-dimethylamino-acetyl-10,11- dihydrobenz[b,f]azepine hydrochloride (Bonnecor, GS 015, AWD 19-166)].

To ensure toxicologically the potential antiarrhythmic agent 3-carbethoxyamino-5-dimethylamino-acetyl-10,11-dihydro-dibenz[b,f] azepine hydrochloride (Bonnecor, GS 015, AWD 19-166), the following preclinical studies have been made up to the present: Determination of the acute toxicity on mice and rats, toxicity test on the rat by repeated applications, study as to the action of GS 015 on the prenatal development of the rat, diverse toxicologic studies on reproduction, mutagenity tests by using the DNA repair test and the Ames test. The results of these studies are represented in a summarized form. A good tolerance of GS 015 can be derived from the results of the preclinical studies gained up to now.

Animals↗

PubMedDate not supplied

Survival of streptococcus in optisol-GS medium.

BACKGROUND: Donor cornea contamination as a cause of endophthalmitis is one of the most serious complications of penetrating keratoplasty. Optisol-GS corneal storage medium with the combination of gentamicin and streptomycin was designed to provide wider antibiotic coverage, most notably against streptococcal species. However, many enterococci are resistant to streptomycin and genta micin. METHODS/RESULTS: We report a case in which Enterococcus faecium was isolated from cultures of the donor limbus prior to corneal excision and again from preoperative cultures of the donor corneal rim despite 5 days of preservation in Optisol-GS. The isolate was found to be resistant to both gentamicin and streptomycin. CONCLUSIONS: This case illustrates the need to raise awareness that streptococcus can remain a viable contaminant of donor corneas despite storage in Optisol-GS medium.

Chondroitin Sulfates↗

PubMedDate not supplied

Lipopolysaccharides (LPS), up-regulate the IL-1-mRNA and down-regulate the glial fibrillary acidic protein (GFAP) and glutamine synthetase (GS)-mRNAs in astroglial primary cultures.

The effect of lipopolysaccharides (LPS), a component of gram-negative bacteria, has been studied in both exponentially growing and confluent morphologically differentiated astroglial cells in primary cultures. The expression of glial fibrillary acidic protein (GFAP) and Glutamine Synthetase (GS) were investigated in parallel with proliferation and expression of IL-1 beta-mRNA. During the exponential growth, proliferation was severely inhibited by LPS. The effect was time- and dose-dependent. On confluent differentiated cells LPS induced an inhibition of cell proliferation which was associated with a down-regulation of GFAP-mRNA, GS-mRNA and GS expressions and with a transitory increase in IL-1 beta mRNA expression. The observed effects might interact with the astroglial developmental program and with the astroglial function.

Animals↗

PubMed1994

Dual signaling potential is common among Gs-coupled receptors and dependent on receptor density.

We studied the relative ability to activate phospholipase C (PLC) of four Gs-coupled receptors expressed in L cells at different densities. Stable cell lines expressing various levels of the luteinizing hormone receptor (LHR), the type 2 vasopressin receptor (V2R), or the type 1 or type 2 beta-adrenergic receptor (beta 1- or beta 2AR) were isolated. The PLC activity was assessed by the measurement of free intracellular Ca2+ concentrations and the accumulation of inositol phosphates. We previously reported that, at 24,000 sites/cell, the LHR in L cells stimulated adenylyl cyclase by 10-fold over basal levels and PLC by 50% over basal levels. The EC50 for stimulation was 20-fold higher for PLC than for adenylyl cyclase. We now report that LHR tends to stimulate PLC more at a higher receptor density and less at a lower density. EC50 values for accumulation of inositol phosphates remained unchanged. The human V2R and the human beta ARs are strong adenylyl cyclase stimulators, and their potential for dual signaling was unknown. Expressing the V2R at 100,000 sites/cell or more and the beta ARs at 300,000 sites/cell resulted in stimulation of PLC by these receptors. As with the LHR, higher concentrations of vasopressin or isoproterenol were needed to reach 50% stimulation of PLC, compared with that of adenylyl cyclase. The beta 1AR was a stronger PLC stimulator than was the beta 2AR. The orders of potency for isoproterenol, epinephrine, and norepinephrine to stimulate adenylyl cyclase and PLC were the same for each of the two beta ARs. These results indicate that the ability of Gs-coupled receptors to stimulate PLC is dependent on the levels of receptor expression, and they suggest that dual signaling potential is a common property of Gs-coupled receptors and possibly also of G(i)-coupled receptors.

Adenylyl Cyclases↗

PubMed1994

Mutation of valine residue unique to alpha subunit of Gs abolishes activation.

We recently characterized a decapeptide sequence (residues 367-376) that is important for the membrane association of the activated alpha subunit of Gs. We report here that when this sequence is replaced by the cognate sequence of Gi1 alpha subunit, the chimeric protein (Gsis alpha) still interacts with the membrane but cannot be activated, regardless of the mode of activation. Construction of various chimeras demonstrates that the single replacement of valine 367 by threonine, the cognate residue of Gi1 alpha subunit, fully reproduces the loss of activation. Analysis of nucleotide interaction reveals that the mutant V367T Gs alpha protein poorly binds GDP or GTP. On the other hand, the conservative change of valine to isoleucine does not alter activation. Interestingly, members of the Gs and G12 classes have a valine and an isoleucine, respectively, at this position, whereas members of the Gi or Gq class contain a threonine residue. The evolutionary relationship between the different classes suggests that the presence of a hydrophobic or a hydrophilic residue is not fortuitous in these alpha subunits and might provide distinctive structural and/or functional properties.

Amino Acid Sequence↗

PubMed1994

Gs is the major G protein involved in interleukin-2-activated natural killer (IANK) cell-mediated cytotoxicity. Successful introduction of anti-G protein antibodies inside streptolysin O-permeabilized IANK cells.

In the present work, anti-G protein antibodies were introduced inside streptolysin permeabilized O interleukin-2-activated natural killer (IANK) cells. Successful entry of the antibodies was determined by flow cytometry and fluorescence microscopy. Permeabilized cells showed typical large granular lymphocyte morphology and remained functional, significantly lysing both NK-sensitive K562 cells and NK-resistant/IANK-sensitive RAJI target cells. This method was utilized to study the effect of anti-G protein antibodies on the functional activities of IANK cells. Anti-Gs antibody inhibited IANK cell killing of RAJI but not of K562 target cells. Further analysis showed that K562 and RAJI cells enhance the binding of guanosine 5'-O-(thiotriphosphate) to IANK cell membranes, and increase the hydrolysis of [32P]GTP in these membranes. Immunoblot analysis showed that K562 and RAJI cells induce the release of alpha o, but not alpha i, alpha s, or alpha q.11 from IANK cell membranes. Cumulatively, these data indicate that putative receptors recognizing K562 or RAJI target cells are coupled to Go in IANK cells, however, only Gs seems to be coupled to receptors recognizing RAJI target cells. Our results point out the importance of Gs protein as a mediator of cellular cytotoxicity of the anti-tumor effector cells.

Animals↗

PubMed1976

[Detection of the GS-antigen of D-type virus in the cells of human breast fibroadenoma].

Gs-antigen(s) of the D-type virus isolated from the continuous cells of human carcinoma was detected by the immunodiffusion with an indirect radioimmunoautographic assay in 5 of 7 human breast fibroadenoma. This virus contained gs-antigen common with the MPMV. These data demonstrated the genom of the D-type virus (or of a similar virus) to be integrated with the human fibroadenoma cells genom. Expression of the virus genom takes place at least to the level of the virus gs-antigen synthesis. The D-type virus from the continuous cell cultures of human carcinoma was associated with some human tumours, one of which was fibroadenoma.

Adenofibroma↗

PubMed1993

[Direct gallstone dissolution therapy with GS-100].

We have developed GS-100, a new direct dissolving drug with strong dissolution property for cholesterol stone by supplementing d-limonene, a dissolvent used since 1974, with 30% medium-chain monoglyceride (MCM). The new drug was applied in 23 patients with gallbladder stones and three with bile duct stone. The presumptive analysis of the composition of the stones was drawn from the CT recordings. As non-invasive therapies, methyl tert-butyl ether (MTBE) dissolution and extracorporeal shock wave lithotripsy (ESWL), which are commonly used in Europe and America, have been reported as being favourable; however, GS-100 is superior in respect to safety and applicative dimension, suggesting of the possibility of using GS-100 as an important drug in the non-invasive therapy for gallstone in the near future.

Adult↗

PubMed1996

Automated DNA typing of ACTBP2: a comparison of allelic ladder with GS 2500 as internal marker.

A comparison was made between the size values of the alleles measured by the internal size marker of Genescan (GS 2500) and the size values measured by an allelic ladder constructed by our laboratory in the application of Genescan software for the typing of the ACTBP2 system. The measurement by GS 2500 showed a greater than 2 bp divergence (SD = 0.893) while the measurement by the allelic ladder showed only 0.1 bp divergence (SD = 0.008). Thus in genotyping of ACTBP2 by Genescan software, the method presented here of using the allelic ladder as the size marker instead of GS 2500 is easier and more reliable.

Alleles↗

PubMed1997

The heterotrimeric GTP-binding protein, GS, modulates the Cl- conductance of rat parotid acinar secretory granules.

Gsalpha has been reported to be present in rat parotid acinar secretory granule membrane (SGM) fractions. In the present study, we evaluated epitope orientation of Gsalpha on the secretory granule (SG) and the ability of Gs to modulate the Cl- conductance of isolated granules by measuring granule lysis. Gsalpha was found to be associated with the cytoplasmic face of the SGM. Aluminum fluroide (AlF4-, 20 microM Al3+ and 10 mM F-) significantly increased granule lysis and this effect was blocked by GDPbetaS. Cholera toxin (5 microg/ml) mimicked the effects of AlF4- on granule lysis, whereas pertussis toxin (0.5 microg/ml) was without effect. GTPgammaS, however, reduced granule lysis in a concentration-dependent manner. The orientation of Gsalpha on the SGM as well as the effects of AlF4- and cholera toxin on granule lysis lends support for a role of Gs in the exocytotic process.

Animals↗

PubMed1997

Enhancement by baclofen of the Gs-coupled receptor-mediated cAMP production in Xenopus oocytes expressing rat brain cortex poly (A)+ RNA: a role of G-protein beta gamma subunits.

We investigated the mechanism by which GABA-B receptors enhance the Gs-coupled receptor-mediated cAMP production in Xenopus oocytes expressing poly (A)+ RNA derived from rat brain cortex. We expressed the cystic fibrosis transmembrane conductance regulator gene (CFTR) as a reporter for cAMP changes in oocytes. The GABA-B agonist (-)baclofen enhanced the adrenergic beta 2 agonist isoproterenol- or vasoactive intestinal peptide (VIP)-induced CFTR currents, whereas (-)baclofen alone did not cause any currents. The (-)baclofen-enhanced currents were inhibited by the GABA-B antagonist 2-OH saclofen. The enhancement by (-)baclofen was further augmented by coexpressing adenylyl cyclase (AC) type II, an isotype activated by G beta gamma and G alpha s, but not by coexpressing AC type III, an isotype insensitive to G beta gamma. Moreover, pretreatment of the oocytes with pertussis toxin (PTX) abolished the enhanced effect of (-)baclofen. These results indicate that upon GABA-B activation, the G beta gamma released from PTX-sensitive G-proteins activates the AC type II (or IV), and this process requires the G alpha s activation by Gs-coupled receptors.

Adrenergic beta-Agonists↗

PubMed1998

Entamoeba histolytica: identification of functional Gs and Gi proteins as possible signal transduction elements in the interaction of trophozoites with fibronectin.

Trophozoites of Entamoeba histolytica adhere to several components of the extracellular matrix. Binding is mediated by specific receptors identified in the parasite surface. Interaction of trophozoites with FN induces the formation of special adhesion structures that are dynamic cytoskeleton membrane complexes and facilitate both adhesion and substrate degradation. The process requires activation of signaling pathways in which PLC, IP3, Ca2-, and PKC participate. These observations, and recent experiments showing increments in cAMP in the trophozoites during the interaction with FN, suggest that FN receptors in the amebic surface could be coupled to G-proteins. We report here that trophozoite plasma membrane peptides of 92, 49, 42, 37, and 21 kDa are ADP-ribosylated by Vibrio cholerae and Bordetella pertussis toxins. Three of them are also recognized by antibodies prepared against the alpha-subunit of Gs-and Gi-proteins. Adenylyl cyclase activity detected in isolated membranes was strongly stimulated by treatment with the toxins. Forskolin (an agonist of the enzyme) and FN also induced increments in the enzymatic activity. Live amebas incubated with the toxins showed enhanced adhesion to FN substrates and a striking reorganization of polymerized actin. The actin rearrangement is reminiscent of the one induced by either forskolin or dibutyril cyclic AMP treatment. Our present data show the presence and the functionality of Gs- and Gi-like proteins and their apparent activation during in vitro interaction of amebas with FN and complement previous observations indicating the operation of signal transduction mechanisms in E. histolytica.

Actins↗

PubMed1999

Neutrophil beta2-adrenergic receptor coupling efficiency to Gs protein in subjects with post-traumatic stress disorder and normal controls.

The symptomatology of post-traumatic stress disorder (PTSD) involves sympathetic hyperarousal. Several of these sympathetic symptoms are mediated through end-organ beta2-adrenergic receptors (beta2AR). Increased sympathetic activity in PTSD could therefore be due to increased betaAR function. This study investigated betaAR function in 30 healthy controls and 20 drug-free PTSD patients. BetaAR binding studies were conducted using antagonist-saturation and agonist-displacement experiments. Measures of beta2AR coupling to Gs protein were derived from agonist-displacement experiments. PTSD patients had significantly higher beta2AR density particularly in the high-conformational state and higher beta2AR coupling than controls, as reflected in a higher percentage of receptors in the high conformational state and a higher ratio of the agonist dissociaton constant from the receptor in the low/high-conformational state. Increased betaAR function in PTSD is consistent with the symptomatology of this disorder. Increased betaAR density and coupling may be consistent with downregulation of betaAR density and uncoupling by antidepressants and may underlie their partial efficacy in PTSD. Dysregulation in Gs protein function is postulated and, agonist-mediated regulation of betaAR expression and/or betaAR kinase activity in PTSD should be investigated in future studies.

Adult↗

PubMed1999

Coupling efficiency of brain beta-adrenergic receptors to Gs protein in suicide, alcoholism and control subjects.

Abnormal beta-adrenergic receptor (betaAR) density in the brains of suicide victims has been reported, although results of studies are inconsistent. Ethanol modifies betaAR-mediated signal transduction. Moreover abnormal betaAR function has been implicated in alcoholism. BetaAR antagonists, which were used as ligands in previous betaAR binding studies, also bind to 5-HT1B/1Dbeta receptors; hence, their estimates of betaAR density are confounded by binding to 5-HT1B/1Dbeta receptors. More importantly, previous studies did not examine betaAR agonist affinity or coupling efficiency to Gs protein. We investigated agonist affinity and coupling efficiency of betaAR to Gs protein in the brains of ten suicide victims, six subjects with alcoholism, and eight controls. There were no differences in betaAR density in either the frontal cortex or hippocampus of suicide victims or alcoholic subjects compared to controls. Preliminary results indicate betaAR supercoupling in suicide victims in both brain regions and uncoupling in alcoholic subjects in the frontal cortex. These results are discussed in view of the existing literature on the role of betaAR in suicide and alcoholism and the mechanism of action of antidepressants.

Adrenergic beta-Antagonists↗

PubMed2001

Radiographic findings and Gs-alpha bioactivity studies and mutation screening in acrodysostosis indicate a different etiology from pseudohypoparathyroidism.

Acrodysostosis is an uncommon skeletal dysplasia associated with nasal hypoplasia, midface deficiency, severe brachydactyly, and varying degrees of hearing loss and mental retardation. Previous publications have suggested that it may be difficult to distinguish acrodystostosis from pseudohypoparathyroidism on clinical grounds, but acrodysostosis does appear to have distinct clinical and radiologic findings. Spinal stenosis is an underappreciated risk in acrodysostosis, despite the reported loss of normal caudal widening of the lumbar interpediculate distance on AP spine radiographs in the original report of this disorder by Robinow et al., with confirmation of these radiographic findings by Butler et al. We report two sporadic cases of acrodysostosis, one of which required decompressive laminectomy for symptomatic spinal stenosis, and review 11 cases of acrodysostosis from 9 families that were submitted to the International Skeletal Dysplasia Registry. The objective of this report is to determine the frequency and severity of spinal stenosis in patients with acrodysostosis and to summarize the clinical and radiographic findings of acrodysostosis in an effort to distinguish acrodysostosis clearly from pseudohypoparathyroidism. The pattern of brachydactyly differs between these two conditions, and varying degrees of spinal stenosis are characteristic of acrodysostosis. Both our index patients with acrodysostosis had normal bioactivity of the alpha subunit of the Gs protein, therefore indicating that acrodysostosis has a different pathogenesis from pseudohypoparathyroidism. Furthermore, single-strand confirmational polymorphism (SSCP) analysis failed to demonstrate any confirmational alterations in the coding exons of the Gs alpha gene. These radiographic and laboratory findings substantiate that acrodysostosis is clinically different from pseudohypoparathyroidism and that it is necessary to follow patients with acrodysostosis for signs of spinal stenosis.

Dysostoses↗

PubMedDate not supplied

Adrenergic receptor function in panic disorder. II. Neutrophil beta 2 receptors: Gs protein coupling, effects of imipramine treatment and relationship to treatment outcome.

Panic attacks are associated with increased autonomic symptoms, suggesting increased beta 2-adrenergic receptor (beta 2AR) function in PD. Tricyclic antidepressants downregulate beta AR function. Previous studies on beta AR function in PD, however, are inconsistent. We recently found increased beta AR coupling and density in neutrophils of symptomatic drug-free PD patients. This study evaluated beta AR coupling to Gs protein in 28 controls, 25 drug-free PD patients and 8 PD imipramine-treated patients. PD patients had significantly higher coupling and receptor density, particularly in the high-conformational state. Differences were more pronounced in patients with less depressive symptomatology. Treatment with imipramine was associated with decreased beta AR coupling and density in the high-conformational state. Several beta AR binding parameters were related to severity of anxiety symptoms and treatment outcome. Antidepressants downregulate beta AR density and induce uncoupling from Gs protein in PD. Future studies may investigate beta AR coupling in relationship to treatment outcome and the role of beta AR kinase in PD.

Adrenergic beta-Antagonists↗