Inhibition of gasotransmitters production and calcium influx affect cardiodynamic variables and cardiac oxidative stress in propofol-anesthetized male Wistar rats 1.

It has been assumed that the cardioprotective effects of propofol are due to its non-anesthetic pleiotropic cardiac and vasodilator effects, in which gasotransmitters (NO, H2S, and CO) as well as calcium influx could be involved. The study on isolated rat heart was performed using 4 experimental groups (n = 7 in each): (1) bolus injection of propofol (100 mg/kg body mass, i.p.); (2) L-NAME (NO synthase inhibitor, 60 mg/kg body mass, i.p.) + propofol; (3) DL-PAG (H2S synthase inhibitor, 50 mg/kg body mass, i.p.) + propofol; (4) ZnPPIX (CO synthase inhibitor, 50 µmol/kg body mass, i.p.) + propofol. Before and after the verapamil (3 µmol/L) administration, cardiodynamic parameters were recorded (dp/dtmax, dp/dtmin, systolic left ventricular pressure, diastolic left ventricular pressure, heart rate, coronary flow), as well as coronary and cardiac oxidative stress parameters. The results showed significant increases of diastolic left ventricular pressure following NO and CO inhibition, but also increases of coronary flow following H2S and CO inhibition. Following verapamil administration, significant decreases of dp/dtmax were noted after NO and CO inhibition, then increase of diastolic left ventricular pressure following CO inhibition, and increase of coronary flow following NO, H2S, or CO inhibition. Oxidative stress markers were increased but catalase activity was significantly decreased in cardiac tissue. Gasotransmitters and calcium influx are involved in pleiotropic cardiovascular effects of propofol in male Wistar rats.

Comparison of short-term and medium-term swimming training on cardiodynamics and coronary flow in high salt-induced hypertensive and normotensive rats.

The aim of present study was to evaluate the effects of 3- and 6-week swimming exercise on cardiodynamics and coronary flow in high salt-induced hypertensive and normotensive rats. 80 male Wistar albino rats (6 weeks old) were divided into 8 groups: hypertensive animals that swam for 3 weeks; hypertensive animals that swam for 6 weeks and their respective sedentary controls; normotensive animals that swam for 3 weeks; normotensive animals that swam for 6 weeks and their respective sedentary controls. Hypertensive animals were on high sodium (8% NaCl solution) diet for 4 weeks, and these animals did not drink tap water during the experimental protocol. After sacrificing, hearts were isolated and perfused according to Langendorff technique at gradually increased coronary perfusion pressure (40-120 cmH2O). The following parameters of cardiac function were continuously recorded: maximum and minimum rate of pressure development in LV, systolic, and diastolic left ventricular pressure, and heart rate. Coronary flow was measured flowmetrically. Findings of the present study may help in better understanding of short- to medium-term exercise-induced direct effects on cardiac function and perfusion. Generally viewed, swimming of both durations did not change myocardial function and perfusion in hypertensive and normotensive conditions.

Reduced Sensitivity to Charge Noise in Semiconductor Spin Qubits via Symmetric Operation.

We demonstrate improved operation of exchange-coupled semiconductor quantum dots by substantially reducing the sensitivity of exchange operations to charge noise. The method involves biasing a double dot symmetrically between the charge-state anticrossings, where the derivative of the exchange energy with respect to gate voltages is minimized. Exchange remains highly tunable by adjusting the tunnel coupling. We find that this method reduces the dephasing effect of charge noise by more than a factor of 5 in comparison to operation near a charge-state anticrossing, increasing the number of observable exchange oscillations in our qubit by a similar factor. Performance also improves with exchange rate, favoring fast quantum operations.

Undoped accumulation-mode Si/SiGe quantum dots.

We report on a quantum dot device design that combines the low disorder properties of undoped SiGe heterostructure materials with an overlapping gate stack in which each electrostatic gate has a dominant and unique function-control of individual quantum dot occupancies and of lateral tunneling into and between dots. Control of the tunneling rate between a dot and an electron bath is demonstrated over more than nine orders of magnitude and independently confirmed by direct measurement within the bandwidth of our amplifiers. The inter-dot tunnel coupling at the [Formula: see text] charge configuration anti-crossing is directly measured to quantify the control of a single inter-dot tunnel barrier gate. A simple exponential dependence is sufficient to describe each of these tunneling processes as a function of the controlling gate voltage.

Recrystallization in different sunscreen formulations after cutaneous application.

BACKGROUND: Data on the structure of sunscreens prior to and after application to the skin and the possible impact of these factors on their efficacy are still scant. AIMS: The microscopic structure of several commercial sunscreen products containing benzophenone-3 (BP-3) was analysed under a light microscope, prior to and 2 h after application of the products to the skin, and compared with various control preparations with or without BP-3. METHODS: All tested formulations were mounted on microscope slides, viewed under a light microscope and photographed. Samples were taken directly from original packages or from freshly prepared prescription formulations. Two hours after application to the skin, the samples were taken and processed for microscopy. RESULTS: In some commercial sunscreens numerous crystals were formed upon cutaneous application, whereas others contained crystals both prior to and after epicutaneous application. A single commercial product (a lamellar ambiphyl emulsion, SPF28) retained its regular structure throughout the study. Control preparations with or without BP-3 and/or octyl methoxycinnamate contained crystals after cutaneous application. CONCLUSIONS: Ingredients, most probably BP-3, in many commercial sunscreens are prone to recrystallization while on the skin which might interfere with their UV light-absorbing function.

[Biomechanical characteristics of spinal cord tissue--basis for the development of modifications of the DREZ (dorsal root entry zone) operation]. / Biomehanicke karakteristike tkiva kicmene mozdine--osnov za razvoj modifikovane tehnike DREZ operacije.

Mechanical properties of the spinal cord tissue--biological basis for the development of the modality of the DREZ surgery lesioning technique Succesful treatment of the chronic neurogenic pain of spinal cord and cauda equina injury origin remains a significant management problem. The mechanism of this pain phenomenon has been shown to be related to neurochemical changes that lead to the state of hypereactivity of the second order dorsal horn neurons. The DREZ surgery (Dorsal Root Entry Zone lesion), designed to destroy anatomy structures involved in pain generating thus interrupting the neurogenic pain mechanism, as a causative procedure in treating this chronic pain, has been performed by using different technical modalities: Radiofrequency (RF) coagulation technic, Laser, Ultrasound and Microsurgical DREZotomy technic. The purpose of the study was to assess the possibility for the establishment of the lesioning technic based on the natural difference in the mechanical properties between the white and gray cord substance. We experimentally deteminated mechanical properties of the human cadaveric cord white versus gray tissue for the purpose of testing possibility of selective suction of the dorsal horn gray substance as a DREZ lesioning procedure. Based on the fact of the difference in tissue elasticity between white and gray cord substance we established a new and simple DREZ surgical lesioning technique that was tested on cadaver cord. For the purpose of testing and comparing the size and shape of the DREZ lesion axchieved the DREZ surgery has been performed on cadaver cord by employing selective dorsal horn suction as a lesioning method. After the procedure cadaver cord underwent histological fixation and analysis of the DREZ lesions achieved. Our result revealed that the white cord substance with longitudinal fiber structure had four time higher dynamical viscosity than gray substance of local neuronal network structure (150 PaS versus 37.5 PaS) that provided possibility for the safe and selective suction of the gray substance of the dorsal horn. Technic includes incision of the dorsolateral sulcus according to Sindous Microsurgical DREZotomy technic than suction under visual control of the dorsal horn gray matter using succer adopted from the lumbar puncture nidle. Operative experimental testing and hystological analysis confirmed expected size and shape of the DREZ lesion performed by dorsal horn suction as DREZ lesioning technique. The utility, selectivity and safety of this technic has been provided by the natural mechanical properties of the cord tissue itself. Application of the Dorsal horn suction as a DREZ lesioning in humans confirmed this technic as a safe and reliable DREZ lesioning method.

[Experimental study of the pathogenesis of frostbite. Part III. Significance of energy status of muscle tissue in the pathogenesis of frostbite]. / Eksperimentalno istrazivanje patogeneze smrzotina--III deo. Znacaj energetskog statusa misicnog tkiva u patogenezi smrzotina.

The authors have investigated energy status of muscle tissue of the lower legs of Wistar rats subjected to freezing, as well as the dependence of ultrastructure changes in muscle tissue mitochondria on the intensity of freezing. The animals were divided into three experimental groups: two groups were exposed to cryoinjury of different intensity, while the third was the control one. Cryoinjury was applied over an experimental after thawing were taken samples of muscle tissue for the analysis of content of energy phosphates and carbohydrates' metabolites, respectively, as well as for morphometric analysis of mitochondria volume out of frozen right and unfrozen left lower legs. Results obtained from different experimental groups were compared mutually and with control group that was not exposed to cryoinjury, respectively. It was found that the freezing in muscle tissue caused hydrops degeneration of mitochondria, depletion of energy reserves, reduction of energy status and the activation of mechanism of anaerobic metabolism. All these alterations were proportional to the intensity of freezing and considerably influenced contractility function of muscle cells, causing prolonged spasm of arterioles in thawed tissue, i.e., rigor congelationis that was primarily defined as an important factor in the pathogenesis of ischemic impairment of thawed tissues.

[Experimental study of the pathogenesis of frostbite. Part II. Role of the sympathetic-adrenergic system in tissue reperfusion immediately after thawing]. / Eksperimentalno istrazivanje patogeneze smrzotina--II deo. Uloga simpaticko-adrenergickog sistema u reperfusiji tkiva neposredno po odmrzavanju.

The authors have investigated the role of sympathetic-adrenergic system in reperfusion of muscular tissue of the feet of Wistar rats immediately after thawing using alpha adrenergic blocker phentolamine methanesulfonate (Regitin). Cryoinjury was applied over an experimental model of local, controlled freezing of different intensity for certain experimental groups. Blood flow through microcirculation was measured by scintigraphy, following Tc-99m-pertechnetate clearance that was given in muscular mass of frozen right, as well as unfrozen left feet of rats. Results obtained in some experimental groups were compared mutually, as well as with the control group that was not exposed to cryoinjury. The investigations have revealed that immediately after thawing existed significant reduction, non-dependent of the intensity of freezing, in blood flow in microcirculation of both frozen and unfrozen feet of rats compared to the control group. Significant increase of microcirculatory blood flow in unfrozen feet was caused by blockade of sympathetic-adrenergic system, while the blood flow remained unchanged in the frozen ones. The reduction of blood flow in microcirculation of frozen tissues immediately after thawing was not associated with sympathetic-adrenergic factor.

[Experimental study of the pathogenesis of frostbite. Part I. Pathohistologic and ultrastructural changes in tissues immediately after thawing]. / Eksperimentalno istrazivanje patogeneze smrzotina--I deo. Patohistoloske i ultrastrukturne promene u tkivima neposredno po odmrzavanju.

Histopathologic and ultrastructural changes in the tissues of frozen extremities of Wistar rats were investigated immediately after thawing. Three experimental groups were formed: two were exposed to cryoinjuries of different intensity, while the third was the control one. Cryoinjury was caused by experimental model of local, controlled freezing of hind, right extremities. Immediately after thawing the tissue samples were taken from frozen right and unfrozen left extremities, in which histopathologic and ultrastructural changes were compared mutually and with control group, respectively. It was observed that the freezing directly caused ultrastructural and histopathologic damage of the tissues that were manifested immediately after thawing and were proportional to the intensity of freezing. Simultaneously, in the tissues existed complex circulatory disorders manifested in open arteriovenous shunts, venous congestion and microcirculatory insufficiency caused by evident spasm of arteriolae that could be considered to be very significant pathogenetic factor in ischemic damage of unfreezed tissues.

[Diagnostic dilemmas in surgical pathology]. / Dijagnosticke dileme u hirurskoj patologiji.

In the majority of presented cases persisted certain diagnostic perplexities even after the careful investigations were performed, which required surgical exploration. For example, carcinomatous pericarditis as the sequel of metastasis from occult thyroid carcinoma and two cases of double malignity (papillary carcinoma and Hodgkin's lymphoma of the thyroid), retroperitoneal leiomyosarcoma and the clear cells renal carcinoma. All the cases were not successfully solved until the application of highly sophisticated and precise methods of immunohistochemical staining, which without a mistake confirmed our assumed histopathologic diagnosis. Metastatic lesion of folicular thyroid carcinoma in the adrenal gland should be mentioned because of the long remission period of 15 years following total thyroidectomy and neck irradiation during the primary therapy of thyroid carcinoma. It is very significant to point out that pathologic disorders such as undifferentiated neoplasm, strange inflammatory conditions, endocrine proliferative lesions deserve special attention because in certain cases consultative approach is necessary for obtaining the definite finding that can in some degree histoprognostically predict the outcome of pathologic process.

[Personal experience with ex tempore diagnosis of neurosurgical biopsies using the smear method]. / Nasa iskusta u ex tempore dijagnostici neurohirurskih biopsija, metodom razmaza.

The results obtained by the use of the smear method were analyzed in ex tempore diagnostics of 240 neurosurgical biopsies, done in the period from 1991 to 1993. Thirty three different pathologic lesions were found that had their special morphology on smears, indicating the high specificity of this method. In 226 cases (94.17%) the diagnosis was established correctly, but in 14 cases (5.83%) it was not: in three cases the diagnosis was falsely negative and in 11 falsely positive. The main causes of the diagnostic errors were analysed and they included the subjective factors and uncommonness of the analyzed tissue samples. The accuracy of 94.17% enabled sufficiently reliable use of this method in ex tempore diagnostics of neurosurgical biopsies.

[Identification of bodies of soldiers carbonized in an armored transport vehicle]. / Identifikacija tela vojnika karbonifikovanih u oklopnom transporteru.

The authors have presented the process and possibilities of identification of the carbonized bodies of the crew of the exploded military armoured transporter. In identification of the invaluable importance have been description, autopsy findings, questionnaires and their comparison as well as ways of identification of the carbonized bodies.

[Morphologic characteristics of persons killed in armored vehicles]. / Morfoloske karakteristike blast povreda poginulih u oklopnim vozilima.

The authors have analysed macroscopic and microscopic changes in tissues and organs of 8 members of the Y.P.A. killed by granate explosion in the armoured vehicles. In all the analysed cases multiple mechanic injuries were found as well as combined mechanothermal injuries. Injuries caused by the blast wave were mainly found in the internal air-containing organs and three cases of solid blast injury were described too.