Echolocation behavior of rufous horseshoe bats hunting for insects in the flycatcher-style

Summary The echolocation behavior ofRhinolophus rouxi when waiting for insects on a perch and when pursuing them in short hunting flights is described. It reveals that flycatcher-style hunting is one foraging strategy utilized by this species. It also suggests that bats use fluttering target information to classify their prey.     

Oxygen distribution in the fluid/gel phases of lipid membranes

The interactions between oxygen and lipid membranes play fundamental roles in basic biological processes (e.g., cellular respiration). Obviously, membrane oxidation is expected to be critically dependent on the distribution and concentration of oxygen in the membrane. Here, we combined theoretical and experimental methods to investigate oxygen partition and distribution in lipid membranes of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) and 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) in a temperature range between 298 and 323 K, specifically focusing on the changes caused by the lipid phase and phase transition. Even though oxygen is known to be more concentrated in the center of fluid phase membranes than on the headgroup regions, the distribution profile of oxygen inside gel-phase bilayers remained to be determined. Molecular dynamics simulations now show that the distribution of oxygen inside DPPC bilayers dramatically changes upon crossing the main transition temperature, with oxygen being nearly depleted halfway from the headgroups to the membrane center below the transition temperature. In a parallel approach, singlet oxygen luminescence emission measurements employing the photosensitizer Pheophorbide-a (Pheo) confirmed the differences in oxygen distribution and concentration profiles between gel- and fluid-phase membranes, revealing changes in the microenvironment of the embedded photosensitizer. Our results also reveal that excited triplet state lifetime, as it can be determined from the singlet oxygen luminescence kinetics, is a useful probe to assess oxygen distribution in lipid membranes with distinct lipid compositions.     

The Effect of Animal-Assisted Therapy on Pain Medication Use After Joint Replacement

Animal-assisted therapy (AAT) has been used in a variety of healthcare settings and studies to evaluate the potential patient benefits are warranted. This retrospective study measured the impact of AAT on the use of oral pain medications by adults after total joint replacement surgery. One group of patients received care in a hospital with an AAT program and the comparison group was in a hospital without an AAT program. Adult patient cohorts were matched on: age, gender, ethnicity, length of stay, and Diagnosis Related Group code for type of total joint replacement. Pain medication doses, converted into morphine equivalent daily doses (MEDD), were compared. Pain medication use was significantly less in the AAT group: 15.32 mg vs. 21.16 (t₍₁₁₉₎ = 2.72, p = 0.007). The effectiveness of AAT in decreasing the need for pain medication and its effect on patient well-being in the post-operative period and in other settings deserves further study.     

Combinatorial modification of natural products: synthesis and in vitro analysis of derivatives of thiazole peptide antibiotic GE2270 A: A-ring modifications

Thiazole peptide GE2270 A (1) possesses potent antimicrobial activity against many gram-positive pathogens, including methicillin resistant Staphylococcus aureus (S. aureus, MRSA; MIC(90)=0.06 microg/mL) and vancomycin resistant Enterococcus spp. (VRE; MIC(90)=0.03 microg/mL); however its poor aqueous solubility has prohibited its development for the clinical treatment of infections. An integrated combinatorial and medicinal chemistry program was employed to identify derivatives of 1 that retain activity but possess greatly enhanced aqueous solubility.     

Effects of phenol in antioxidant metabolism in matrinxã, Brycon amazonicus (Teleostei; Characidae)

Parameters of the antioxidant defense systems of Brycon amazonicus (matrinx?--a neotropical fish) exposed to phenol for 96 h plus the recovery over 1 and 2 weeks were studied in erythrocytes and liver. Hematocrit increase was observed during phenol exposure and recovery for 1 week. Total superoxide dismutases (SOD), glutathione peroxidase (GPx) and reduced glutathione (GSH) did not change during phenol exposure. Erythrocyte glucose-6-phosphate dehydrogenase (G6PDH) increased during that period while catalase (CAT) activity decreased during phenol exposure and recovery for 2 weeks. In the liver, SOD and CAT did not change, whereas GPx increased in the first week of recovery and decreased after 2 weeks. A late response was observed for G6PDH activity which increased only at the second week. Ascorbate concentration in the brain decreased during phenol exposure and increased over recovery. From our results it appears that the oxidative stress was limited in matrinx? exposed to phenol, but seemed to occur during the recovery period.     

Utility of nociceptive flexion reflex threshold and bispectral index to predict movement responses under propofol anaesthesia

Introduction: The nociceptive flexion reflex threshold (NFRT) is a promising tool to monitor analgesia during general anaesthesia. Clinical studies have shown that the NFRT allows to predict movement responses to painful stimuli under a combined anaesthetic regime of sedative and opioid agents. Experimental studies indicated that the NFRT is also able to predict such movement responses under an exclusively sedative regime like propofol mono-anaesthesia. Therefore, we performed this study to investigate the ability of the NFRT to predict movement responses to painful stimuli in patients during a clinical propofol mono-anaesthesia.

Methods: We investigated 140 cardiac surgery patients during their postoperative phase under propofol mono-anaesthesia. NFRT and bispectral index (BIS) were determined in each patient right before endotracheal suctioning or painful electrical test stimulation. Prediction probabilities were calculated to quantify how accurate each measure is able to predict movement responses to the stimuli.

Results: The 124 patients included in the analysis received a median propofol dosage of 3.2 (2.5–3.9) [median (IQR)] mg/kg/h. The included patients showed 287 movement responses after a total of 725 investigated stimuli. The prediction probabilities for positive movement responses were 0.63 (95%CI: 0.59–0.67) for the NFRT and 0.69 (95%CI: 0.65–0.73) for the BIS.

Conclusions: The NFRT allows the prediction of movement responses under propofol mono-anaesthesia, which confirms its utility as a monitor to predict movement responses under general anaesthesia. The BIS allows an even more accurate prediction, although it does not reflect the physiological structures of movement suppression, but correlates closely with the dose of propofol.

Trial registration: German clinical trial register (DRKS00003062, Deutsches Register Klinischer Studien).     

Künstliche Kreuzungsmethoden bei Steinklee und Luzerne

Ohne Zusammenfassung     

Untersuchungen an dem Antirrhinum-Wildsippen-Sortiment von E. Baur

Ohne ZusammenfassungMit 23 Textfiguren     

The Munich Wistar Fr?mter rat: proteinuria and blood pressure in correlation to the number of superficial glomeruli.

Rats with a high number of superficial nephrons (MWF/Ztm) also show an elevated urinary protein excretion and a high systolic blood pressure. To investigate a possible correlation between the number of superficial glomeruli and these physiological changes, MWF/Ztm rats were crossed and backcrossed to Wistar cryptorchic (WC/Ztm) animals with no superficial nephrons in order to produce genotypes with differing numbers of superficial glomeruli. In the parental strains, the F1 hybrids and the 8 possible backcrosses, the number of superficial glomeruli, the distance of the 10 most superficial glomeruli to the renal surface, and the diameter of Bowman's capsules were determined by morphometric analysis. The excretion of total protein, in detail low molecular weight proteins, albumin, and high molecular weight proteins were measured quantitatively in 5 males of each genotype. Systolic blood pressure was determined by a tail-cuff method in conscious rats. Means of each variate of the 12 available genotypes were linearly correlated and demonstrate a close correlation between the amount of superficial nephrons and the observed physiological changes, i.e. the more superficial the glomeruli the higher the urinary protein excretion, especially albumin, and the higher the systolic blood pressure.     

Rad9 protects cells from topoisomerase poison-induced cell death

Previous studies have suggested two possible roles for Rad9 in mammalian cells subjected to replication stress or DNA damage. One model suggests that a Rad9-containing clamp is loaded onto damaged DNA, where it participates in Chk1 activation and subsequent events that contribute to cell survival. The other model suggests that Rad9 translocates to mitochondria, where it triggers apoptosis by binding to and inhibiting Bcl-2 and Bcl-x(L). To further study the role of Rad9, parental and Rad9(-/-) murine embryonic stem (ES) cells were treated with camptothecin, etoposide, or cytarabine, all prototypic examples of three classes of widely used anticancer agents. All three agents induced Rad9 chromatin binding. Each of these agents also triggered S-phase checkpoint activation in parental ES cells, as indicated by a caffeine-inhibitable decrease in [3H]thymidine incorporation into DNA and Cdc25A down-regulation. Interestingly, the ability of cytarabine to activate the S-phase checkpoint was severely compromised in Rad9(-/-) cells, whereas activation of this checkpoint by camptothecin and etoposide was unaltered, suggesting that the action of cytarabine is readily distinguished from that of classical topoisomerase poisons. Nonetheless, Rad9 deletion sensitized ES cells to the cytotoxic effects of all three agents, as evidenced by enhanced apoptosis and diminished colony formation. Collectively, these results suggest that the predominant role of Rad9 in ES cells is to promote survival after replicative stress and topoisomerase-mediated DNA damage.