ABSTRACT
To maximise the effect of a small fluid load, it is occasionally desirable to bolus manually with multiple depressions of a large-capacity syringe. This is usually achieved by placing the syringe on the side port of a three-way tap. We modified this technique by placing two-one-way valves in line with the three-way tap, effectively creating a piston pump, the infusion rates via which we compared with those achieved by an inflatable pressure-infuser in a simulated resuscitation. Fluid flow was faster using the piston pump than with the pressure-infuser (mean (SD) time to infuse 2000 ml saline 0.9% via a 16-G cannula 352 (10) s vs 495 (19) s, respectively, p < 0.0001). The piston pump appears to have potential for both tight control of fluid delivery and major high-volume resuscitation. The lightweight nature of the pump and its lack of reliance on gravity may also make it suitable for the pre-hospital setting.
Subject(s)
Fluid Therapy/instrumentation , Infusion Pumps , Equipment Design , Fluid Therapy/methods , Humans , Infusions, Intravenous/instrumentation , Sodium Chloride/administration & dosage , Syringes , Time Factors , Transducers, PressureSubject(s)
Dementia/genetics , Dementia/pathology , Muscle Weakness/genetics , Muscle Weakness/pathology , Myositis, Inclusion Body/genetics , Myositis, Inclusion Body/pathology , Osteitis Deformans/genetics , Osteitis Deformans/pathology , Urinary Incontinence, Urge/genetics , Urinary Incontinence, Urge/pathology , Adult , DNA/genetics , DNA Mutational Analysis , Female , Humans , Intercellular Signaling Peptides and Proteins , Magnetic Resonance Imaging , Male , Middle Aged , Pedigree , Peptides/genetics , Urinary Incontinence, Urge/etiology , Young AdultABSTRACT
Mammalian circadian rhythms are synchronized daily to light-dark cycles in the environment. The suprachiasmatic nucleus (SCN) is the proposed site of the major circadian pacemaker. Daily entrainment is believed to be influenced by inputs to the SCN, one of these being the dense serotonergic (5-HT) projection from the raphe nuclei. WAY-100635 is a potent and selective 5-HT1A receptor antagonist. In this study, the effects of WAY-100635 on phase-shifts of the hamster circadian pacemaker to light were investigated. Phase-delays after a light pulse administered during the early subjective night (15 min at CT14) were observed to be significantly greater following pre-treatment with WAY-100635 compared to light pulse alone (P < 0.05). However, pre-treatment with WAY-100635 had no effect on the magnitude of phase-shifts to light at CT18, late in the subjective night. Serotonin may influence the responsiveness of the circadian pacemaker to photic stimuli. Specifically, WAY-100635 administered at CT14 can augment phase-shifts to light.
Subject(s)
Circadian Rhythm/drug effects , Circadian Rhythm/radiation effects , Light , Piperazines/pharmacology , Pyridines/pharmacology , Receptors, Serotonin/drug effects , Serotonin Antagonists/pharmacology , Animals , Cricetinae , Male , Receptors, Serotonin, 5-HT1ABSTRACT
The aim of this study was to investigate whether enhanced levels of endogenous cytokinins could influence plant development, particularly leaf senescence. Tobacco plants were transformed with the Agrobacterium tumefaciens gene tmr, under the control of the soybean heat shock promoter HS6871. This gene encodes the enzyme isopentenyl transferase, which catalyzes the initial step in cytokinin biosynthesis. After heat shock, the cytokinin level increased greatly and the level of tmr mRNA, undetectable at 20[deg]C, rose and remained high for up to 8 hours. The levels of cytokinin and tmr mRNA were substantially lower by 24 hours. Transformed plants grown at 20[deg]C were shorter, had larger side shoots, and remained green for longer than untransformed plants. The differences were more pronounced after several heat shocks of whole plants or defined areas of leaves. Our results demonstrated that plant morphology and leaf senescence can be manipulated by changing the endogenous level of cytokinins.
