The effects of intraperitoneal injections of various doses of A9-tettahydrocannabinol (A”-THC) on brain levels of cyclic adenosine 3’,5’-monophosphate (cyclic AMP) have been studied in mice. Doses of A9-THC in the range of 0.1 to 1.0 mgikg cause a 5&160 per cent elevation of cyclic AMP levels compared to controls (P < O.OOOS), while doses of A9THC in the range of 2.0 to 10.0 mg/kg cause a 3@-60...

mixed clayey soils occur as mixtures of sand (or gravel) and clay in widely varying proportions. their engineering behavior has not been comprehensively studied yet. an experimental program, comprising monotonic, cyclic, and post-cyclic triaxial tests was undertaken on compacted clay-granular material mixtures, having different proportions of clay and sand or gravel. this paper presents the res...

Influences of light and darkness on l-phenylalanine ammonia-lyase activity of black locust (Robinia pseudoacacia) seedlings were studied. Light initiates both an increase in enzyme activity (or enzyme synthesis) and a subsequent decrease in activity. These dual influences of light create cyclic changes in l-phenylalanine ammonia lyase activity in continuous light. The cyclic changes in activity...

Transmural stimulation of, or application of nicotine to, the isolated rabbit sinoatrial (SA) node resulted in initial negative and late positive chronotropy. Simultaneous application of acetylcholine and norepinephrine produced a similar biphasic chronotropic effect. These procedures produced an initial increase in cyclic guanosine 3':5'-monophosphate (cyclic GMP) and a delayed elevation in cy...

M AINTAINING perioperative optimal cardiac preload in surgical patients is paramount for precise hemodynamic management. Hypovolemia may result in tissue hypoperfusion and worsened organ dysfunction, whereas fluid overload appears to impede oxygen delivery and compromise patient outcome. Several clinical and experimental studies have demonstrated the usefulness of dynamic indices based on heart...

Changes in anterior knee laxity (AKL), genu recurvatum (GR) and general joint laxity (GJL) were quantified across days of the early follicular and early luteal phases of the menstrual cycle in 66 females, and the similarity in their pattern of cyclic variations examined. Laxity was measured on each of the first 6 days of menses (M1-M6) and the first 8 days following ovulation (L1-L8) over two c...

PURPOSE Females vary substantially in their multiplanar cyclic knee laxity changes across the menstrual cycle. The biomechanical implications of these cyclic changes are relatively unknown. Our purpose was to first cluster females based on their cyclic changes in anterior knee laxity (AKL), genu recurvatum (GR), varus-valgus (VV), and internal-external (IER) rotation knee laxity across the mens...

AIM Human periodontal ligament (PDL) cells incur changes in morphology and express proteins in response to cyclic strain. However, it is not clear whether cyclic strain, especially excessive cyclic strain, induces PDL cell apoptosis and if so, what mechanism(s) are responsible. The aim of the present study was to elucidate the molecular mechanisms by which pathological levels of cyclic strain i...

Hyperpolarization-activated cyclic nucleotide-modulated (HCN) channels control cardiac and neuronal rhythmicity. HCN channels contain cyclic nucleotide-binding domain (CNBD) in their C-terminal region linked to the pore-forming transmembrane segment with a C-linker. The C-linker couples the conformational changes caused by the direct binding of cyclic nucleotides to the HCN pore opening. Recent...

Cyclic changes in dissolved oxygen occur naturally in shallow estuarine systems, yet little is known about the adaptations and responses of estuarine organisms to cyclic hypoxia. Here we examine the responses of Palaemonetes pugio, a species of grass shrimp, to cyclic hypoxia (1.5-8 mg/l dissolved oxygen; 4.20-22.42 kPa) at both the molecular and organismal levels. We measured alterations in ge...