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INTRODUCTION: Pneumoperitoneum, widely used in laparoscopic surgery increases the intraabdominal pressure, leading to hypoperfusion of the abdominal organs, and promoting the buildup of reactive oxygen species(ROS) and inflammatory cytokines which in turn impairs the body postoperatively. Aim of our investigation was to evaluate the potential protective effects of short ischemic episodes on ischemic damages. METHODS: 70 Wistar rats were used, divided into 7 groups: 1st group sham, 2nd group pneumoperitoneum with 5 mmHg, 3rd group preconditioning with 5 mmHg, 4th group: postconditioning with 5 mmHg, 5th group pneumoperitoneum with 10 mmHg, 6th group: preconditioning with 10 mmHg, 7th group postconditioning with 10 mmHg. Pneumoperitoneum was created by Veres needle. Oxidative stress parameters: malondialdehyde (MDA) concentration, reduced glutathione (GSH), sulfhydril (SH-), myeloperoxidase (MPO) levels and superoxide-dismutase (SOD) activity were measured. We measured TNF-α and IL-6 concentrations. We monitored the activation of anti- and proapoptotic common signaling pathways (bax, bcl-2, p53) during the early phase of reperfusion. Histology was made from kidney samples. RESULTS: GSH concentrations were significantly reduced, MDA concentrations were significantly higher in each group compared to the Sham. SOD enzyme: a pressure of 10 mmHg elicited significantly greater damage than 5 mmHg. There was a significantly higher SOD activity in group 10 mmHg IPC compared to 10 mmHg. We found that the expression of bax was considerably higher in the none conditioned groups. Noticeably higher expression of anti-apoptotic bcl-2 level was measured in 10 mmHg IPC and 10 mmHg IPoC groups. In case of p53 expression: significant decrease could be seen in groups 10 mmHg IPC and 10 mmHg IPoC compared to the 10 mmHg group. CONCLUSION: Based on our results, the elevated intraabdominal pressure due to pneumoperitoneum induces oxidative stress, which is dependent on the applied pressure. Mostly precondiotioning – but also postconditioning – reduces surgical stress following laparoscopic procedures. In order to explore its mechanism it requires further investigations. [ABSTRACT FROM AUTHOR]

The vapor pressure differences between a mixture of (CH4+CD4) and CH4 and between CD4 and CH4 were measured simultaneously with the CH4 vapor pressure. This was done at 29 temperatures between 97 and 122 K, and for six different mixtures, of compositions 0.150, 0.250, 0.375, 0.500, 0.625, and 0.750 mole fraction in CD4. These mixtures exhibit very small positive deviations from Raoult’s law. Calculated excess Gibbs energies for equimolar mixtures were 0.60 J mol-1 at 100 K and 0.42 J mol-1 at 120 K. These values of GE are 2 to 3 orders of magnitude smaller than those typically found in binary mixtures of simple nonisotopic species. The molar excess enthalpy, calculated from the temperature dependence of GE, is HE(x=0.5)=(1.5±0.2) J mol-1. The experimental results were used to test three theoretical models: the vdW-1 fluid theory, 1cLJ perturbation theory, and the theory of isotope effects in mixtures. While the first two proved to be inadequate, the isotope effect theory agrees well with experiment. [ABSTRACT FROM AUTHOR]

Background and Purpose: Sensory neuropathy develops in the presence of cardiovascular risk factors (e.g. diabetes, dyslipidemia), but its pathological consequences in the heart are unclear. We have previously shown that systemic sensory chemodenervation by capsaicin leads to impaired myocardial relaxation and diminished cardiac nitric oxide (NO) content. Here we examined the mechanism of diminished NO formation and if it may lead to a reduction of peroxynitrite (ONOO(-))-induced S-nitrosylation of sarcoendoplasmic reticulum Ca(2+)-ATPase (SERCA2a).Experimental Approach: Male Wistar rats were treated with capsaicin for 3 days to induce sensory chemodenervation. Seven days later, myocardial function and biochemical parameters were measured.Key Results: Capsaicin pretreatment significantly increased left ventricular end-diastolic pressure (LVEDP) decreased cardiac NO level, Ca(2+)-dependent NO synthase (NOS) activity, and NOS-3 mRNA. Myocardial superoxide content, xanthine oxidoreductase and NADPH oxidase activities did not change, although superoxide dismutase (SOD) activity increased. Myocardial and serum ONOO(-) concentration and S-nitrosylation of SERCA2a were significantly decreased.Conclusions and Implications: Our results show that sensory chemodenervation decreases cardiac NO via decreased expression and activity of Ca(2+)-dependent NOS and increases SOD activity, thereby leading to decreased basal ONOO(-) formation and reduction of S-nitrosylation of SERCA2a, which causes impaired myocardial relaxation characterized by increased left ventricular end-diastolic pressure (LVEDP). This suggests that capsaicin sensitive sensory neurons regulate myocardial relaxation via maintaining basal ONOO(-) formation and SERCA S-nitrosylation. [ABSTRACT FROM AUTHOR]

Revascularization after long term aortic ischaemia in vascular surgery induces reperfusion injury accompanied with oxidative stress and inflammatory responses. The hypothesis of this study was that the aortic occlusion followed by controlled reperfusion (CR) can reduce the ischaemia-reperfusion injury, the systemic and local inflammatory response induced by oxidative stress. Animal model was used. Control group: animals underwent a 4-hour infrarenal aortic occlusion followed by continuous reperfusion. Treated group: animals were treated with CR: after a 4-hour infrarenal aortic occlusion we made CR for 30 minutes with the crystalloid reperfusion solution (blood: crystalloid solution ratio 1:1) on pressure 60 Hgmm. Blood samples were collected different times. The developing oxidative stresswas detected by the plasma levels of malondialdehyde, reduced glutathion, thiol groups and superoxide dismutase. The inflammatory response was measured by phorbol myristate acetateinduced leukocyte reactive oxygen species production and detection of change in myeloperoxidase levels. The animals were anaesthetized one week after terminating ligation and biopsy was taken from quadriceps muscle and large parenchymal organs. CR significantly reduced the postischaemic oxydative stress and inflammatory responses in early reperfusion period. Pathophysiological results: The rate of affected muscle fibers by degeneration was significantly higher in the untreated animal group. The infiltration of leukocytes in muscle and parenchymal tissues was significantly lower in the treated group. CR can improve outcome after acute lower-limb ischaemia. The results confirm that CR might be also a potential therapeutic approach in vascular surgery against reperfusion injury in acute limb ischaemia. Supported by OTKA K108596. [ABSTRACT FROM AUTHOR]

The distribution of spinal primary afferent terminals labeled transganglionically with the choleratoxin B subunit (CTB) or its conjugates changes profoundly after perineural treatment with capsaicin. Injection of CTB conjugated with horseradish peroxidase (HRP) into an intact nerve labels somatotopically related areas in the ipsilateral dorsal horn with the exceptions of the marginal zone and the substantia gelatinosa, whereas injection of this tracer into a capsaicin-pretreated nerve also results in massive labeling of these most superficial layers of the dorsal horn. The present study was initiated to clarify the role of C-fiber primary afferent neurons in this phenomenon. In L5 dorsal root ganglia, analysis of the size frequency distribution of neurons labeled after injection of CTB-HRP into the ipsilateral sciatic nerve treated previously with capsaicin or resiniferatoxin revealed a significant increase in the proportion of small neurons. In the spinal dorsal horn, capsaicin or resiniferatoxin pretreatment resulted in intense CTB-HRP labeling of the marginal zone and the substantia gelatinosa. Electron microscopic histochemistry disclosed a dramatic, ∼10-fold increase in the proportion of CTB-HRP-labeled unmyelinated dorsal root axons following perineural capsaicin or resiniferatoxin. The present results indicate that CTB-HRP labeling of C-fiber dorsal root ganglion neurons and their central terminals after perineural treatment with vanilloid compounds may be explained by their phenotypic switch rather than a sprouting response of thick myelinated spinal afferents which, in an intact nerve, can be labeled selectively with CTB-HRP. The findings also suggest a role for GM1 ganglioside in the modulation of nociceptor function and pain. [ABSTRACT FROM AUTHOR]

A new, rapid method is described which permits the genotyping of genetically modified animals from a microlitre volume of whole blood samples via one step polymerase chain reaction amplification. The major advantage of the presented method is the exclusion of a DNA preparation step, which significantly reduces the time expenditure and work load of the genetic testing. Pilot studies indicate, that this method is efficient and applicable also on tissue biopsies and larger amount of blood providing a rapid and reliable new technique over conventional genotyping approaches. [ABSTRACT FROM AUTHOR]

Objective: We studied the protective effects of postconditioning (PS) in healthy and hypercholesterolemic rats after renal ischaemia-reperfusion (IR) injury. We aimed to examine cytokine expression and apoptosis in tissue damage after revascularisation (TNF-α levels in serum and tissue). Methods: Male Wistar rats (n = 32) were divided into four groups. The animals of normal feed groups (NF) were fed with normal rat chow and the cholesterol feed groups (CF) were fed with 1.5% cholesterol containing diet for 8 weeks. Anaesthetized rats underwent a 45-min cross-clamping in both kidney pedicles. Ischaemia was followed by 120-min reperfusion with or without PS protocol (group PS vs. IR). Postconditioning was induced by four intermittent periods of ischaemia-reperfusion of 15-s duration each. Serum cholesterol, triglyceride, urea and creatinine levels were determined. Proinflammation was characterized by the measurement of serum TNF-α. Tissue injury in kidney was determined by formaline-fixed, paraffin-embedded tissue sections. Tissue TNF-α levels were determined by immunohistochemistry. Results: Significant elevation was observed in serum TNF-α level after IR injury in normal feed groups, which was reduced by PS. In CF group neither the elevation nor the postconditioning induced reduction were as significant as in the NF groups. In normal feed group PS caused a significant reduction in tissue TNF-α level which was significantly higher in CF. Conclusions: Ischaemic postconditioning proved to be an effective defense against IR in NF groups, but it was ineffective in CF groups in kidney tissue. [ABSTRACT FROM AUTHOR]

Introduction: The challenge against reperfusion injury and tissue oxidative stress, especially in vascular surgical interventions has an essential importance to reach the optimal clinical result. Numerous experimental attempts have proved the positive antioxidant effect of vitamin E in both chronic and acute phase models. In our study we monitored the effect of continuous preoperative treatment with vitamin E, on oxidative stress and tissue inflammation reactions developed after reconstructive operations. Patients and methods: 32 patients have been involved in a randomized, prospective study, all suffering from AFS occlusion proved by angiography, and all undergone supragenual reconstruction. Duration of ischemia and amount of tissues under vascular clamping were almost the same in all patients. In the group treated with E-vitamin, we administered 1×200 mg of vitamin E p/o from the preoperative day till the 7th post operative day. Patients of the second group did not receive vitamin E. Materials and methods: Peripheral blood samples were collected immediately before operation and at the end of the second reperfusion hour (early reperfusion period). Late reperfusion period has been monitored by analyzing blood samples taken at 24th hour and 7th day next to the operative ischemia. Among oxidative stress parameters, direct measurement of reactive oxygen intermediator (ROI) and determination of antioxidant state (GSH, Total-SH group, SOD) have been performed. Malondialdehyde was chosen as marker for lipidperoxidation. Inflammation reactions were monitored up on expression of adhesion molecules (CD11a and CD18). We also controlled the oscillation of myeloperoxidase (MPO) activity. Results: Our study has proved that preoperative (from the preoperative day till the 7th post operative day) administration of 200 mg vitamin E could reduce the level of oxidative stress developed after ischemic-reperfusion insult (lipidproxidation, antioxidant enzymes). According to our results, the prooxidant-antioxidant imbalance also diminished in the group with E-vitamin treatment. We proved that elective administration of vitamin E could decrease the WBC activity (MPO activity, free radicals production, expression of adhesion molecules) and its consequential local inflammation process, during early reperfusion. [ABSTRACT FROM AUTHOR]

Background: The indication of surgical treatment in lower limb compartment syndrome mostly depends on the clinical signs which can be often uncertain, resulting in delayed insufficient intervention. Aim: The aim of the study was to evaluate the progression of compartment syndrome by measuring of intracompartmental pressure and monitoring of decreased tissular oxygenation, indicating an insufficient secondary microcirculation. Materials and methods: 16 patients were examined in our study (12 males, 4 females, mean age: 62.7±9.5 years), who underwent acute lower limb revascularization surgery for a critical (lasting more than 4 hours) limb ischemia. The indications were: 5 iliac artery embolizations and 11 femoral artery occlusions. After revascularization, on the second postoperative day, we detected significant lower limb edema and swelling of several grade. To monitor the elevated intracompartmental pressure (ICP) and to evaluate the extremital circulation, we used KODIAG pressure meter and the tissular oxygen saturation (StO2) was measured by near-infrared-spectroscopy. Results: In 12 cases the ICP exceeded the critical 40 mmHg. In these patients the average StO2 was 50–53%, in spite of complete recanalization. In these cases we made urgent, semi-open fasciotomy. In 4 cases, where the clinical aspect showed compartment syndrome, the measured parameters did not indicate a surgical intervention (ICP: 25–35 mmHg, StO2: around normal). Summary: A novel approach in our examination is that, besides empirical therapeutic guidelines generally applied in clinical practice, we established an objective, parameter-based (“evidence based medicine”) surgical indication strategy for the lower limb compartment syndrome. Our parameter results produced by the above pressure and saturation measurements help the clinicians to decide between conservative and operative treatment of the disease. [ABSTRACT FROM AUTHOR]

Objective: We studied the protective effects of ischaemic postconditioning (PS) on ischemia–reperfusion injury of the lower extremities in a rat model of abdominal aortic intervention. We aimed to examine the evoked oxidative stress, cytokine expression and leukocyte activation after revascularisation surgery. Methods: Anesthetized animals (48 Whistar rats) underwent a 60 min infrarenal aorta cross-clamping. After the ischaemic period, an intermittent 4 times 15 s reperfusion – 15 seconds ischaemic episodes – were applied (ischaemic postconditioning: group PS). Then we started a 120 min reperfusion in the aorta. In untreated group animals underwent a long ischaemia (60 min) and the following reperfusion (group IR). Peripherial blood samples were collected before operation, and in early (5, 10, 15, 30, 60 and 120 min) reperfusion periods. Serum peroxide level, TNF-alpha concentration, myeloperoxidase (MPO) activity and PMA-induced leukocyte ROS production were measured. Results: In PS group, plasma peroxide level elevation was significantly lower in very early reperfusion (5–30 min) comparing to non-conditioned IR group (10.04±1.9 μM/l vs. 16.91±3.67 μM/l, p<0.05). PS also reduced serum TNF-alpha concentration (167.41±31.26 μg/ml vs. 116.55±12.04 μg/ml, p<0.05), MPO activity (1.759±0.239 μM/ml vs. 1.22±0.126 μM/ml, p<0.05) and leukocyte activation detected by PMA-induced leukocyte ROS production (5.7±0.96 AU/103 cells vs. 4.63±0.69 AU/103 cells). Conclusions: Ischaemic postconditioning could reduce ROI production after IR in early reperfusion period, thus limiting ROI mediated tissue lesion, cytokine–leukocyte activation and inflammatory responses. PS seems to be an effective tool in vascular surgery to reduce reperfusion injuries after revascularization interventions. [ABSTRACT FROM AUTHOR]

After revascularization of an acute arterial occlusion the development of a serious ischaemic-reperfusion injury is a menacing challenge and a hard task in peripheral vascular surgery. A whale of evidences point to oxidative stress, as an important trigger, in the complex chain of events leading to reperfusion injury. In the present study authors aimed to examine oxidative stress parameters, antioxidant–prooxidant state and leukocyte adhesion molecules (CD11a and CD18) expression following acute revascularization surgery of lower limb. 10 patients were examined in the prospective randomized study. Peripheral blood sample was collected in ischaemic period, and after reperfusion in the 2nd and 24th hours, and on 7th day. Superoxide-dismutase activity, reduced glutathion concentration and leukocytes free radical production were measured. The degree of lipidperoxidation was marked with the quantity of malondialdehyde. The expressions of adhesion molecules were measured with flowcytometry. The speed and rate of free radical production significantly increased in the early reperfusion (p<0.05). The level of antioxidant enzymes decreased after revascularization. The CD11a and CD18 expression of the granulocytes significantly (p<0.05) decreased right after the revascularization, but with a gradual elevation until the 7th day they exceed the ischaemic value. Our results showed a time specific turnover of the sensitive antioxidant–prooxidant balance after revascularization operation. [ABSTRACT FROM AUTHOR]

In 3-methylpyridine--heavy water mixture, the segregation in the closed-loop phase diagram in relation to the temperature and heavy water concentration was studied by dynamic neutron radiography (DNR) at the 10 MW VVR-SM Research Reactor in Budapest, Hungary. On the pixel properties of the DNR images, taken from the phase separation process by Iman 2β v. image analyzing program, polynomial fitting, 3-D intensity histograms were applied. For modeling the segregation process, a two-variable segregation model: S = f(T, D) was set up. From the partial differentiation of the function f with respect to the temperature it was established that the highest rate changes in the segregation take place in the region of 50-55 °C and are modified by 3-methylpyridine concentration. The increase in the segregation process progresses up to 93-96°C, then declines. [ABSTRACT FROM AUTHOR]

Examination of the neurogenic inflammatory response of the skin renders direct information on the functional state of the chemosensitive sensory nerve endings involved in neurogenic vasodilatation of skin vessels. Using a recently developed diagnostic test, the present study furnishes experimental evidence on the impairment of axon reflex vasodilatation following herpes zoster. The possible mechanisms by which herpes zoster may effect the vascular reactions of the skin arc briefly discussed. [ABSTRACT FROM AUTHOR]

Positive excess molar Gibbs energies were detected in liquid mixtures of ([sup 36]Ar+[sup 40]Ar) using a high-accuracy double differential manometric technique. The vapor pressure differences between a mixture of ([sup 36]Ar+[sup 40]Ar) and [sup 40]Ar and between [sup 36]Ar and [sup 40]Ar were measured simultaneously with the vapor pressure of [sup 40]Ar. Four different mixtures were selected and 80 temperatures were chosen in the 85-96 K temperature range. The results show that the vapor pressure of an equimolar liquid mixture is greater than what would be expected if the solution were strictly ideal, by approximately 2.5 Pa in the 85-96 K temperature range. The calculated excess Gibbs energy for the equimolar mixture at 85 K is G[sub 1/2][sup E]=(0.021±0.004) J mol[sup -1]. For the excess molar enthalpy a value of H[sub 1/2][sup E]=(0.12±0.04) J mol[sup -1] was found. The corresponding deviations from Raoult's law are therefore extremely small (3 to 4 orders of magnitude smaller than those typically found in binary mixtures of nonisotopic constituents). The evidence of nonideal behavior in such a fundamental and simple system is relevant for the interpretation of the properties of liquid mixtures of more general importance. The pitfalls of the determination of activity coefficients through the comparison between vapor pressure isotope effect data and liquid-vapor isotope fractionation factors are discussed in some detail. The results were used to test three theoretical models, namely, the vdW-1 fluid theory, the 1cLJ perturbation theory, and the statistical theory of isotope effects in mixtures. While the first two proved to be inadequate, the isotope effect theory agrees reasonably well with experiment. The excess Gibbs energy of monatomic isotopic mixtures are related with the molar volume isotope effect and with the mean Laplacian of the potential energy in the liquid phase. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]

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