A rapid impairment of myocardial impedance occurs after 30 minutes of coronary occlusion, and its onset is better defined by shift in phase angle than by rise in tissue resistivity. Phase 1b arrhythmias are associated with marked impedance changes, and both are delayed by preconditioning. Reversion of ST-segment elevation is partially associated with impairment of myocardial impedance, but other factors play a role as well.

The investigation of processes of ischemia in different organ tissues is very important for the development of methods of protection and preservation during surgical procedures. Electrical impedance spectroscopy was used to distinguish between different tissues and their degree of ischemia. We describe mathematical methods used to adjust experimental data to Cole-Cole models for one-circle and two-circle impedance loci and a study of the main parameters for representing the behavior of ischemia in time. In vivo and in situ postmortem measurements of different tissues from pigs are shown in the 100 Hz to 1 MHz range. The Cole parameters that best characterize the ischemia are R0 and fc.

The metacarpal fractures are common fractures which are treated by orthopaedic surgeons, plastic surgeons and hand surgeons equally. These are seen in young adults who have active life style. These have a major impact in life style of the patients if these are not treated adequately. The management of the fractures vary among surgeons to surgeons; two surgeons in the same centre can have a different treatment plan for a fracture. There are no standard guidelines for the treatment and it ranges from conservative management, Kirschner's wire (K-wires), plates and screws. This review article is about the management of metacarpal fractures where the commonly done procedures are reviewed.

The 2-amino-3-oxohexahydroindolizino[8,7-b]indole-5-carboxylate system (IBTM) has been proposed as a dipeptide surrogate of type II‘ β-turns. To evaluate which of the 11bR and 11bS diastereomers of IBTM best reproduces the conformational properties of type II‘ β-turns, gramicidin S (GS), a cyclic antibiotic peptide that contains two such units, has been chosen as a test compound and the effect of either diastereomer on both conformation and activity of the resulting peptide analogues has been determined. A conventional approach to the cyclic peptide structure based on solution cyclization of a partially protected precursor was only practicable for the (S)-IBTM diastereomer. As an alternative, a solid phase mediated cyclization approach has been devised and applied successfully to both gramicidin S and its Lys2,2‘ analogue, then extended to the (R)-IBTM-containing analogues. NMR conformational analysis has clearly shown that only the (R) diastereomer of IBTM is a suitable mimic of the type II‘ β-turn conformation typical of GS. Differences in antibacterial activity between the (S)- and (R)-IBTM-containing GS analogues confirm the conformational results.

A one-month-old transmural infarction is a low resistance, noncapacitative medium that allows a good transmission of current pulses and of ST segment potential changes generated by contiguous peri-infarction ischemia.

No abstract

No abstract

No abstract