ABSTRACT
Ceftazidime is the only anti-pseudomonal beta-lactam that has been reported to be administered by extended infusion in pediatric cystic fibrosis (CF) patients. A small pediatric pharmacokinetic/pharmacodynamic study has been published regarding the use of intermittent extended infusion doripenem in the treatment of an acute pulmonary exacerbation (APE) in pediatric CF patients; however, clinical use of intermittent extended infusion doripenem in pediatric CF patients has not been previously reported. We present three cases administering intermittent extended infusion doripenem in pediatric CF patients for the treatment of an APE in the case of replacing meropenem due to shortage. The delivery of beta-lactam antibiotics via intermittent extended infusion should be considered in order to optimize the pharmacodynamics of beta-lactams in the treatment of an APE.
Subject(s)
Anti-Bacterial Agents/therapeutic use , Burkholderia Infections/drug therapy , Carbapenems/therapeutic use , Cystic Fibrosis/drug therapy , Pseudomonas Infections/drug therapy , Adolescent , Anti-Bacterial Agents/supply & distribution , Burkholderia Infections/complications , Burkholderia cenocepacia/isolation & purification , Child , Cystic Fibrosis/complications , Cystic Fibrosis/microbiology , Disease Progression , Doripenem , Drug Therapy, Combination , Female , Gram-Negative Bacterial Infections/complications , Gram-Negative Bacterial Infections/drug therapy , Humans , Infusions, Intravenous , Meropenem , Pseudomonas Infections/complications , Pseudomonas aeruginosa/isolation & purification , Pseudomonas stutzeri/isolation & purification , Rhodospirillaceae/isolation & purification , Thienamycins/supply & distribution , Tobramycin/therapeutic use , Treatment Outcome , Trimethoprim, Sulfamethoxazole Drug Combination/therapeutic useABSTRACT
When guard cell protoplasts (GCPs) of tree tobacco [Nicotiana glauca (Graham)] are cultured at 32 degrees C with an auxin (1-napthaleneacetic acid) and a cytokinin (6-benzylaminopurine), they reenter the cell cycle, dedifferentiate, and divide. GCPs cultured similarly but at 38 degrees C and with 0.1 micro M +/- -cis,trans-abscisic acid (ABA) remain differentiated. GCPs cultured at 38 degrees C without ABA dedifferentiate partially but do not divide. Cell survival after 1 week is 70% to 80% under all of these conditions. In this study, we show that GCPs cultured for 12 to 24 h at 38 degrees C accumulate heat shock protein 70 and develop a thermotolerance that, upon transfer of cells to 32 degrees C, enhances cell survival but inhibits cell cycle reentry, dedifferentiation, and division. GCPs dedifferentiating at 32 degrees C require both 1-napthaleneacetic acid and 6-benzylaminopurine to survive, but thermotolerant GCPs cultured at 38 degrees C +/- ABA do not require either hormone for survival. Pulse-labeling experiments using 5-bromo-2-deoxyuridine indicate that culture at 38 degrees C +/- ABA prevents dedifferentiation of GCPs by blocking cell cycle reentry at G1/S. Cell cycle reentry at 32 degrees C is accompanied by loss of a 41-kD polypeptide that cross-reacts with antibodies to rat (Rattus norvegicus) extracellular signal-regulated kinase 1; thermotolerant GCPs retain this polypeptide. A number of polypeptides unique to thermotolerant cells have been uncovered by Boolean analysis of two-dimensional gels and are targets for further analysis. GCPs of tree tobacco can be isolated in sufficient numbers and with the purity required to study plant cell thermotolerance and its relationship to plant cell survival, growth, dedifferentiation, and division in vitro.
Subject(s)
Adaptation, Physiological , Cell Cycle , Nicotiana/cytology , Plant Leaves/cytology , Protoplasts/cytology , Temperature , Abscisic Acid/pharmacology , Animals , Bromodeoxyuridine/metabolism , Cell Cycle/drug effects , Cell Survival/drug effects , Cells, Cultured , HSP70 Heat-Shock Proteins/metabolism , Mitogen-Activated Protein Kinase 3 , Mitogen-Activated Protein Kinases/chemistry , Mitogen-Activated Protein Kinases/metabolism , Naphthaleneacetic Acids/pharmacology , Plant Leaves/drug effects , Plant Leaves/metabolism , Protoplasts/drug effects , Rats , S Phase , Time Factors , Nicotiana/drug effects , Nicotiana/metabolismABSTRACT
⢠Under red light in ambient CO2 guard cells of faba bean (Vicia faba) fix CO2 and accumulate sucrose, causing stomata to open. We examined whether at [CO2 ] low enough to limit guard cell photosynthesis stomata would open when illuminated with red (R) or far-red (FR) light. ⢠After illumination with R or FR in buffered KCl solutions, net stomatal opening was c. 3 µm (R and FR) in air containing 210-225 µl l-1 CO2 and was 5 µm (R) or 6.5 µm (FR) in air containing 40-50 µl l-1 CO2 . Opening was fully inhibited by 3-(3,4-dichlorophenyl)-1,1 dimethyl urea, the calmodulin antagonist W-7, the ser/thr kinase inhibitor ML-9, and sodium orthovanadate, but not by dithiothreitol, which inhibits formation of zeaxanthin, the blue light photoreceptor of guard cells. ⢠Stomatal opening was accompanied by K+ uptake and starch loss. Similar results were obtained when leaves were exposed to conditions designed to lower intercellular leaf [CO2 ]. ⢠These data suggest that the guard cell chloroplasts transduce reduced [CO2 ], activating stomatal opening through an ion uptake mechanism that depends on chloroplastic photosynthetic electron transport and that shares downstream components of the blue light signal transduction cascade.
ABSTRACT
Sleep-related obstructive respiratory disturbances in childhood differ significantly from the adult's obstructive sleep apnea syndrome (OSAS). In contrast to adults, in children with OSAS the disturbance of the macrostructure of sleep, the increase of the number of apneas and hypopneas, and the diminution of oxygen saturation are not so prominent. Restlessness of the sleep, as reflected by movement arousals together with cortical (electroencephalograph-recorded) arousals, is important. The combination of clinical symptoms and polysomnographic parameters is necessary to diagnose OSAS in children.
