Extracellular and Intracellular Activities of PAF

1987 ◽  
pp. 255-271 ◽  
Author(s):  
Peter M. Henson
Keyword(s):  
Intracellular Activities

Changes in intracellular activities of lysosomal enzymes in tissues of rats during aging

1979 ◽  
Vol 10 (1-2) ◽  
pp. 81-92 ◽  
Author(s):  
Shingo Asano ◽  
Hideoh Komoriya ◽  
Etsuko Hayashi ◽  
Hideo Sawada
Keyword(s):  
Lysosomal Enzymes ◽  
Intracellular Activities

scholarly journals In Vitro and Intracellular Activities of LBM415 (NVP PDF-713) against Legionella pneumophila

2005 ◽  
Vol 49 (6) ◽  
pp. 2533-2535 ◽  
Author(s):  
Paul H. Edelstein ◽  
Baofeng Hu ◽  
Martha A. C. Edelstein
Keyword(s):  
Legionella Pneumophila ◽  
Intracellular Growth ◽  
Intracellular Activities

ABSTRACT LBM415 activity against extracellular and intracellular Legionella pneumophila was studied. The LBM415 MIC50 for 20 Legionella sp. strains was 4 μg/ml, versus 0.06, 0.25, and ≤ 0.03 μg/ml for azithromycin, erythromycin, and levofloxacin, respectively. LBM415 (0.5 and 16 μg/ml) reversibly prevented intracellular growth of two L. pneumophila strains and was less active than erythromycin.

Intracellular activities during volume regulation byNecturus gallbladder

1984 ◽  
Vol 78 (3) ◽  
pp. 187-199 ◽  
Author(s):  
Richard S. Fisher ◽  
Kenneth R. Spring
Keyword(s):  
Volume Regulation ◽  
Intracellular Activities

Postnatal regulation of 2,3-DPG in sheep erythrocytes

1983 ◽  
Vol 245 (3) ◽  
pp. H506-H512
Author(s):  
P. A. Mueggler ◽  
S. Carpenter ◽  
J. A. Black
Keyword(s):  
Fetal Sheep ◽  
L Cells ◽  
Erythrocyte Concentration ◽  
Glycolytic Control ◽  
Concentration Changes ◽  
Intracellular Activities ◽  
Quantitative Changes ◽  
Glycolytic Rate ◽  
2,3 Dpg

The erythrocyte 2,3-diphosphoglycerate (2,3-DPG) concentrations of sheep change markedly during the 1st mo following birth. From measurements of erythrocyte glycolytic enzymes and intermediate concentrations, we have identified the mechanism regulating erythrocyte 2,3-DPG in postnatal sheep. The postnatal changes in erythrocyte 2,3-DPG do not result from qualitative or quantitative changes in the intracellular activities of the Rapoport-Luebering shunt enzymes, 2,3-DPG mutase or 2,3-DPG phosphatase. The postnatal 2,3-DPG changes result from changes in the erythrocyte concentration of 1,3-DPG, which is controlled by other reactions in the glycolytic pathway. Neither changes in the glycolytic control enzymes (hexokinase, phosphofructokinase, and pyruvate kinase) nor changes in the intrinsic glycolytic rate can account for these 1,3-DPG concentration changes. 1,3-DPG concentrations are regulated by the in vivo glycolytic rate, which is controlled by the intracellular concentration of glucose, the glycolytic substrate. Glucose concentrations are 0.3 mmol/l cells in erythrocytes of fetal sheep (135-140 days gestational age), increase following birth to a peak of 3.8 mmol/l cells by the 1st wk of age, and then decline to the normal adult levels of 0.5 mmol/l cells by the end of the 1st mo.

scholarly journals Cellular mechanisms of potassium homeostasis in the mammalian nervous system

1987 ◽  
Vol 65 (5) ◽  
pp. 1038-1042 ◽  
Author(s):  
P. Grafe ◽  
K. Ballanyi
Keyword(s):  
Guinea Pig ◽  
Glial Cells ◽  
Sympathetic Ganglia ◽  
Olfactory Cortex ◽  
Lateral Olfactory Tract ◽  
Cellular Mechanisms ◽  
Potassium Homeostasis ◽  
Ion Sensitive Microelectrodes ◽  
Sympathetic Neurones ◽  
Intracellular Activities

Double-barrelled ion-sensitive microelectrodes were used to measure changes in the intracellular activities of K+, Na+, and Cl− (aKi, aNai, aCli) in neurones of rat sympathetic ganglia and in glial cells of slices from guinea-pig olfactory cortex. In sympathetic neurones, carbachol and γ-aminobutyric acid (GABA) produced a reversible decrease of aKi. The decrease of aKi during carbachol was accompanied by a rise of aNai, whereas in the presence of GABA decreases of aKi and aCli were seen. The reuptake of K+ released during the action of carbachol was completely blocked by ouabain, whereas furosemide inhibited the aKi recovery after the action of GABA. In glial cells, in contrast to the observations in the sympathetic neurones, aKi and aCli increased, whereas aNai decreased when neuronal activity was enhanced by repetitive stimulation of the lateral olfactory tract. It was found that barium ions and ouabain strongly reduced the activity-related rise of intraglial aKi in slices of guinea-pig olfactory cortex. These data show that mammalian neurones as well as glial cells possess several K+ uptake mechanisms that contribute to potassium homeostasis. Ouabain, furosemide, and Ba2+ are useful pharmacological tools to separate these mechanisms.

Antituberculosis activities of clofazimine and its new analogs B4154 and B4157.

1996 ◽  
Vol 40 (3) ◽  
pp. 633-636 ◽  
Author(s):  
V M Reddy ◽  
G Nadadhur ◽  
D Daneluzzi ◽  
J F O'Sullivan ◽  
P R Gangadharam
Keyword(s):  
Multidrug Resistant ◽  
New Drugs ◽  
Drug Resistant ◽  
Antituberculosis Drugs ◽  
Resistant Tuberculosis ◽  
Chemotherapeutic Activity ◽  
Resistant Strains ◽  
Intracellular Activities ◽  
Moderate Resistance ◽  
Drug Resistant Strains

In our efforts to develop new drugs for the treatment of tuberculosis, especially that caused by multidrug-resistant strains, we investigated clofazimine (CFM) and two of its analogs, B4154 and B4157, for their antituberculosis activities. Twenty M. tuberculosis strains were tested, including 16 drug-resistant strains (strains resistant to one or more antituberculosis drugs), for their susceptibilities to these three agents. All of the strains were found to be susceptible to B4154 and B4157, and one strain showed moderate resistance to CFM. The MICs of B4154, B4157, and CFM at which 90% of strains were inhibited were 0.25, 0.12, and < or = 1.0 microgram/ml, respectively. The intracellular activities of CFM and B4157 were superior to that of B4154. The chemotherapeutic activities of the three compounds were evaluated in C57BL/6 mice. At a dose of 20 mg/kg of body weight, the activity of CFM was slightly superior to that of B4157; however, both compounds prevented mortality and caused a significant reduction in the numbers of CFU in the lungs and spleens. The animals treated with B4157 showed less pigmentation than animals treated with CFM. The chemotherapeutic activity of CFM was comparable to those of rifampin and isoniazid. Complete susceptibility of multidrug-resistant strains to CFM and B4157 and the therapeutic efficacies of these compounds against mouse tuberculosis make these drugs attractive agents for the treatment of drug-resistant tuberculosis.

scholarly journals Demonstration of lactase activity in culture medium of melon cells

2011 ◽  
Vol 31 (No. 4) ◽  
pp. 132-135
Author(s):  
J. Stano ◽  
K. Mičieta ◽  
E. Tokhtaeva ◽  
M. Valšíková ◽  
M. Koreňová ◽  
...  
Keyword(s):  
Cell Suspension ◽  
Culture Medium ◽  
Agar Plate ◽  
Cell Suspension Cultures ◽  
Callus Cultures ◽  
Suspension Cultures ◽  
Lactase Activity ◽  
Seedling Roots ◽  
Intracellular Activities

Lactase activity was detected in a&nbsp;culture medium of the cell suspension culture of watermelon (Citrullus vulgaris L.). A&nbsp;simple, rapid and reproducible procedure for identification of extracellular lactase is described using callus cultures of seedlings from the tested plant, hairy roots of 2.5 days old seedlings of watermelon germinating on agar plates as well as cell suspension cultures derived from callus cultures. For the determination of intracellular activities of lactase, 6-bromo-2-naphthyl-&beta;-D-galactopyranoside and p-nitrophenyl-&beta;-D-galactopyranoside were used as synthetic substrates. The extracellular lactase activity was determined by evaluating the day-zone in agar medium. The enzyme from watermelon callus cultures and seedling roots, cultivated on agar plates supplemented with 6-bromo-2-naphthyl-2-bromo-&beta;-D-galactopyranoside, hydrolyzed this substrate releasing 6-bromo-naphthyl. By simultaneous coupling with hexazonium p-rosaniline or Fast Blue BB the corresponding azo dye was formed. The parallel extracellular and intracellular activities were determined in cell suspension cultures derived from callus cultures. The results show a&nbsp;43.8% intracellular and 54.2% extracellular distribution of lactase activity. The described agar plate method enables a&nbsp;rapid, simple and specific detection of plant processes of extracellular lactase. &nbsp;

scholarly journals Intra- and Extracellular Activities of Dicloxacillin against Staphylococcus aureus In Vivo and In Vitro

2010 ◽  
Vol 54 (6) ◽  
pp. 2391-2400 ◽  
Author(s):  
Anne Sandberg ◽  
Klaus Skovbo Jensen ◽  
Pierre Baudoux ◽  
Françoise Van Bambeke ◽  
Paul M. Tulkens ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Multiple Dosing ◽  
Time Curve ◽  
Highly Active ◽  
Intracellular Activities ◽  
Unit Reduction ◽  
Peritonitis Model ◽  
Extracellular Activity

ABSTRACT Antibiotic treatment of Staphylococcus aureus infections is often problematic due to the slow response and recurrences. The intracellular persistence of the staphylococci offers a plausible explanation for the treatment difficulties because of the impaired intracellular efficacies of the antibiotics. The intra- and extracellular time- and concentration-kill relationships were examined in vitro with THP-1 cells and in vivo by use of a mouse peritonitis model. The in vivo model was further used to estimate the most predictive pharmacokinetic/pharmacodynamic (PK/PD) indices (the ratio of the maximum concentration of drug in plasma/MIC, the ratio of the area under the concentration-time curve/MIC, or the cumulative percentage of a 24-h period that the free [f] drug concentration exceeded the MIC under steady-state pharmacokinetic conditions [fT MIC]) for dicloxacillin (DCX) intra- and extracellularly. In general, DCX was found to have similar intracellular activities, regardless of the model used. Both models showed (i) the relative maximal efficacy (1-log-unit reduction in the numbers of CFU) of DCX intracellularly and (ii) the equal relative potency of DCX intra- and extracellularly, with the MIC being a good indicator of the overall response in both situations. Discordant results, based on data obtained different times after dosing, were obtained from the two models when the extracellular activity of DCX was measured, in which the in vitro model showed a considerable reduction in the number of CFU from that in the original inoculum (3-log-unit decrease in the number of CFU after 24 h), whereas the extracellular CFU reduction achieved in vivo after 4 h did not exceed 1 log unit. Multiple dosing of DCX in vivo revealed increased extra- and intracellular efficacies (2.5 log and 2 log units of reduction in the numbers of CFU after 24 h, respectively), confirming that DCX is a highly active antistaphylococcal antibiotic. PK/PD analysis revealed that fT MIC is the index that is the most predictive of the outcome of infection both intra- and extracellularly.

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