Time of out-of-hospital cardiac arrest is not associated with outcome in a metropolitan area: A multicenter cohort study.

AIM: Whether time of day influences survival after out-of-hospital cardiac arrest (OHCA) remains controversial. We compared outcomes after OHCA between day and night and explored whether characteristics of pre-hospital advanced life support (ALS)-quality varied by time of day. METHODS: We conducted a prospective cohort study of individuals that suffered a non-traumatic OHCA in the city of Vienna between August 2013 and August 2015 and who received resuscitative efforts by EMS. We compared clinical outcomes between day and night, defined as 7:00 pm-7:00 am based on EMS shift time including rates of sustained return of spontaneous circulation (ROSC), 30-day survival and favourable neurologic outcome (cerebral performance category 1 or 2). ALS quality measures included time to first medical contact, time to first shock, total dose of epinephrine, and multiple ALS performance measures. RESULTS: We included 1811 patients (37% female) with a mean age of 67 ± 16 years in our analyses. Rates of ROSC and 30-day survival with favourable neurological outcome did not differ between day or night (30% vs 28%, p =  0.33; 12% vs. 11%, p =  0.51, respectively). These results remained unchanged after multivariate adjustment for ROSC (RR, 1.1; 95% CI, 1.0-1.3, p = 0.19) and 30-day survival with favourable neurological outcome (RR, 1.2; 95% CI, 1.0-1.5, p =  0.10). The quality of ALS did not differ between day and night. CONCLUSIONS: In contrast to previous studies, there was no significant difference in sustained ROSC rates and 30-day survival with favourable neurological outcome after OHCA between day and night in the city of Vienna. This is likely due to nearly identical high bystander CPR rates and identical ALS performance provided by EMS personnel irrespective of time of the day.

Elastodynamic shape modeler: a tool for defining the deformation behavior of virtual tissues.

A main goal of surgical simulators is the creation of virtual training environments for prospective surgeons. Thus, students can rehearse the various steps of surgical procedures on a computer system without any risk to the patient. One main condition for realistic training is the simulated interaction with virtual medical devices, such as endoscopic instruments. In particular, the virtual deformation and transection of tissues are important. For this application, a neuro-fuzzy model has been developed, which allows the description of the visual and haptic deformation behavior of the simulated tissue by means of expert knowledge in the form of medical terms. Pathologic conditions affecting the visual and haptic tissue response can be easily changed by a medical specialist without mathematical knowledge. By using the personal computer-based program Elastodynamic Shape Modeler, these conditions can be adjusted via a graphical user interface. With a force feedback device, which is similar to a real laparoscopic instrument, virtual deformations can be performed and the resulting haptic feedback can be felt. Thus, use of neuro-fuzzy technologies for the definition and calculation of virtual deformations seems applicable to the simulation of surgical interventions in virtual environments.

Antimicrobial substances and effects on sessile bacteria.

Biofilms occur in natural aquatic ecosystems and on surfaces of biomaterials. They are generally associated with clinical infections predominantly of prosthetic hip joints, heart valves and catheters. Sessile microorganisms may be intimately associated with each other and to solid substratum through binding to and inclusion into exopolymer matrices on biofilms. The establishment of functional colonies within the exopolymeric matrices generate physico-chemical gradients within biofilms, that modify the metabolism and cell-wall properties of the microorganism. A consequence of biofilm growth is an enhanced microbial resistance to chemical antimicrobial agents and antibiotics. Investigations on the antimicrobial efficacy of antibiotics, antiseptics and antimicrobial heavy ions, however, gave controversial results. No single antimicrobial substance has been developed for the efficient eradication of adherent bacteria. This review elucidates the mechanisms of microbial resistance in biofilms and strategies for the prevention of biofilm development. Pharmacokinetical and pharmacodynamical issues for the screening of biofilm-active drugs are presented. Combinations of antistaphylococcal antibiotics with rifampin may be advantageous for preventing and curing biomaterial infections.

Taurine-like immunoreactivity in octopaminergic neurones of the cockroach, Periplaneta americana (L.).

Taurine (2-aminoethanesulphonic acid) is reported to interact with the octopaminergic system. The distribution of taurine-like immunoreactivity (-LIR) in relation to octopamine-like immunoreactive dorsal unpaired median (DUM) neurones was investigated with the aim of revealing possible colocalization of these two neuromediators. The specificity of the anti-taurine serum used was demonstrated by dot blot immunoassay and by use of preabsorption controls. There was no crossreactivity with octopamine. The specificity of the octopamine antiserum employed has been described elsewhere. Taurine-LIR could be demonstrated in large dorso-median cells in the suboesophageal and the mesothoracic ganglion as well as in the abdominal ganglia. In addition taurine-LIR is distributed in numerous other regions of the ganglia. A comparison of the immunostaining for taurine and octopamine indicates that several of the taurine-like immunoreactive (-LI) neurones are probably members of the octopamine-immunoreactive DUM cell population. These taurine-LI neurones resemble octopamine-LI DUM cells in soma position and size as well as in the projections of their primary neurites. Colocalization of octopamine-LIR and taurine-LIR within the same neuronal element could be shown by alternate immunostaining of consecutive sections. It is probable that all octopamine-LI DUM neurones also exhibit taurine-LIR, and the possible physiological significance of this coexistence is discussed.

A new specific antibody reveals octopamine-like immunoreactivity in cockroach ventral nerve cord.

An antiserum was raised in rabbits immunized with octopamine conjugated to thyroglobulin. The specificity of this antiserum for octopamine is shown by dot blot immunoassay analysis. The antiserum does not crossreact with dopamine, noradrenaline, and serotonin, but slight crossreactivity with the amine tyramine at high concentrations was observed. The tyramine crossreactivity could be eliminated by preabsorption with a tyramine-glutaraldehyde-BSA conjugate. Using this antiserum, we describe the topographical distribution of octopamine-immunoreactive (ir) neuronal elements in wholemounts and paraffin sections of the ventral nerve cord of the American cockroach. The pattern of octopamine immunostaining is completely different from that obtained with an antidopamine serum, and can be blocked by preabsorbing the antioctopamine serum with BSA-conjugated octopamine. Cell bodies and dendritic processes of putatively octopaminergic dorsal (DUM) and ventral (VUM) unpaired median neurons were clearly octopamine-ir in all ganglia examined. The numbers of stained DUM somata in the mesothoracic, metathoracic, and terminal ganglion of females correspond to those of peripherally projecting DUM cells revealed previously by retrograde tracing (Gregory, Philos Trans R Soc Lond [Biol] 306:191, 1984; Tanaka and Washio, Comp Biochem Physiol 91A:37, 1988; Stoya et al., Zool Jb Physiol 93:75, 1989). In addition, various, previously unknown, paired cells with octopamine-like immunoreactivity were found in all ventral ganglia except abdominal ganglia 3-6. Some of these probably project intersegmentally.

The octopaminergic system within the ventral nerve cord of the American cockroach.

Octopamine-immunoreactive neurons within the ventral nerve cord of the cockroach, Periplaneta americana, were mapped with a new anti-octopamine serum. The specificity of this antiserum was demonstrated by dot blot immunoassay and by comparing the immunocytochemical staining patterns obtained after incubation with anti-dopamine and anti-octopamine serum. Putative octopaminergic dorsal and ventral unpaired median (DUM resp. VUM) neurons showed octopamine-like immunoreactivity in all ventral ganglia. The numbers of DUM cells in the mesothoracic, metathoracic and terminal ganglia of females correspond to those previously characterized by retrograde staining 19, 33, 34. It could be shown that besides segmentally projecting there are also intersegmentally projecting DUM neurons within the thoracic ganglia. In addition various, previously unknown, paired octopamine-ir cells were revealed in all ventral ganglia except the abdominal ganglia 2-5.