Mitral regurgitation and coronary artery bypass surgery: comparison of mitral valve repair and replacement.

BACKGROUND: The aim of this retrospective study was to determine if there is a statistically significant difference (p < or = 0.05) between mitral valve repair (MVRp) with concomitant surgical revascularization of the myocardium (CABG) and mitral valve replacement (MVR) with concomitant CABG, considering the duration of surgery, early postoperative morbidity, in-hospital mortality, length of stay in the Intensive Care Unit (ICU) and overall in-hospital stay. METHODS: Between January 1st 2006 and December 31st 2008, 75 patients underwent surgery for mitral regurgitation and ischemic heart disease. Patients were divided in two groups determined by the procedure that was performed on the mitral valve (MVRp + CABG group had 34 patients, MVR + CABG group had 41 patients). All the patients were operated by the same surgical team and received the usual anaesthesia protocol. RESULTS: Patients in the MVR + CABG group had statistically significant higher EuroSCORE risk levels, higher NYHA status and higher incidence of postoperative low cardiac output syndrome (LCOS). Neurological complications showed statistically significant higher incidence in the MVRp + CABG group. There was no statistically significant difference in regard to in-hospital mortality between these two groups. Patients in the MVR + CABG group had statistically significant longer in-hospital stay. CONCLUSIONS: Mitral valve repair and mitral valve replacement are complementary methods considering early postoperative morbidity and mortality. Higher incidence of LCOS and in-hospital stay in the MVR + CABG group was to be expected on behalf of poorer preoperative status.

The effect of occlusal relationships on the occurrence of sounds in the temporomandibular joint.

The aim of this investigation was to determine the influence of occlusal relationships on the occurrence of sounds in the temporomandibular joint. A group of 100 male subjects aged 24-52 years (X = 35.03+/-6.92) was examined. Analysis of occlusion included determination of the number of existing teeth, number of teeth in occlusion, overbite and overjet, type of occlusion, mediotrusion interferences, relationship of the retruded contact position (RCP) to intercuspal position (ICP), and the amount and direction of sliding from RCP to ICP. Sound was registered by means of a stethoscope and classified according to its character in click or crepitation. Sound was present in 29% of subjects. In 28% of cases it was registered as click and in 2% of cases as crepitation. One subject had simultaneous click and crepitation. The results of the statistical analysis indicate that overbite, type of occlusion, existence of mediotrusion interferences, the relationship of RCP to ICP, and the amount and direction of sliding from RCP to ICP do not have an influence on the occurrence of sounds. The risk of the occurrence of crepitation is significantly increased in the case of the loss of more than 5 teeth, and in the case of horizontal overbite larger than 7.5 mm (p<0.05).

Fluidity of the myelin sheath in the peripheral nerves of diabetic rats.

In the present study we examined the structural integrity of the myelin sheath in the peripheral nerves from short-term streptozotocin (STZ)-treated diabetic rats, using ESR spectroscopy as a tool in determining the dynamic state and the structure of the myelin lipid phase. Experiments were performed on spin-labeled sciatic and sural nerves from STZ-treated Hannover-Wistar rats and age-matched controls. The spectrum analysis employed a numerical simulation model with the set of fitting parameters that in the same time relate the ESR line shape and structure and dynamics of the probed environment. The simulation considered three spectral components weighted and summed in the composite spectrum. The comparative analysis of results showed the fraction of the spectral component II to be significantly increased in the spectra of diabetic rats, indicating the significant increase in overall fluidity of the myelin structure. The origin of fluidity changes was further investigated using an experimental model for demyelination (local injection of ethidium bromide in vivo), proteolytic action of trypsin in vitro, and osmotic myelin swelling in vitro. Analysis and comparison of the results suggested a conclusion in terms of changed biophysical properties of the myelin lipid phase in peripheral nerves in the pathology of diabetes.

Lipid domains in the exoplasmic and cytoplasmic leaflet of the human erythrocyte membrane: a spin label approach.

The existence of different lipid domains in the monolayers of the human erythrocyte membrane was investigated at 4 degrees C by employing spin-labelled phospholipid analogues. Spectra of analogues located exclusively either in the exoplasmic or in the cytoplasmic leaflet of erythrocyte membranes were recorded. Spectra were simulated by variation of order parameter describing the average amplitude of motion of the long molecular axis of the nitrogen 2 p pi orbital of the spin label and of the respective correlation times. For both leaflets at least three components were required to fit the experimental spectra, differing mainly in the order parameter. While the parameters of each component are not very different between both membrane halves, the relative contribution of each component to the spectrum is different between the exoplasmic and cytoplasmic leaflet. The order parameter of the most fluid component, presumably resembling the lipid bulk phase, is smaller in the cytoplasmic leaflet in comparison to the exoplasmic one. The lateral coexistence of different lipid domains in the human red blood cell membrane is concluded. The molecular nature of those domains is discussed.