Dietary versus post-mortem use of oregano oil and/or α-tocopherol in turkeys to inhibit development of lipid oxidation in meat during refrigerated storage

The dietary and post-mortem uses of oregano oil in turkeys to inhibit development of lipid oxidation in breast and thigh meat during refrigerated storage were investigated. Using minced meat, patties were prepared from turkey meat post-mortem added with either 200 mg oregano oil or alpha-tocopherol/kg, meat from turkeys dietary supplemented with either 200 mg oregano oil or alpha-tocopheryl acetate/kg feed, and control meat. All patties were cooked, placed in a refrigerated cabinet at 4 degrees C, and lipid oxidation was assessed by monitoring malondialdehyde formation after 3, 6 and 9 days of storage. Treatments significantly (P<0.05) retarded lipid oxidation in both breast and thigh meat patties at all storage times compared with controls. The dietary supplementation of either oregano oil or alpha-tocopheryl acetate exhibited the highest antioxidative activity compared with the other treatments. Post-mortem addition of either oregano oil or alpha-tocopherol to the minced meat also retarded lipid oxidation in the prepared patties compared with controls; however, this effect was inferior to that of the dietary supplementation even though the post-mortem alpha-tocopherol supplemented meat contained 90-fold more alpha-tocopherol than patties from the dietary supplemented meat. Thigh meat was more susceptible to oxidation than breast meat, although the former contained alpha-tocopherol at markedly higher levels. Supplementing the diet with 200 mg oregano oil/kg, alpha-tocopherol levels in the breast and thigh meat significantly (P<0.05) increased compared with control. This increase could not be attributed to the alpha-tocopherol already present in the oregano oil since post-mortem addition of oregano oil to control breast and thigh meat at the same dose could not actually increase the alpha-tocopherol concentrations.

Blepharoptosis due to Kearns-Sayre syndrome

A 16-year-old patient suffering from Kearns-Sayre syndrome presented with severe blepharoptosis. A levator advancement procedure was performed. It seems that in conjunction with medical treatment, blepharoptosis surgery offers good and hopefully long lasting results to patients suffering from this rare syndrome.

Recombinant Sabin environmental isolates in Greece and Cyprus

AIMS

Twenty-one polioviruses (PVs) Sabin strains were isolated from sewage treatment plants from Metamorphosis, Athens, Greece during the time period from May to October 1996, and from two other sites located at Nicosia and Limassol in Cyprus between April and December 2003 were retrospectively investigated for the detection of recombinant PVs.

METHODS AND RESULTS

Three PVs isolates were found as tripartite recombinants, S3/S2/S1 in the 2C genomic viral region. The first recombination site S3/S2 was located close to the 5' end of 2C while the second recombination site S2/S1 was located towards the 3' end of 2C. Such recombination is a rare event producing a tripartite hybrid 2C protein. Three more PVs isolates were characterized as bipartite S2/S1 recombinants and one as S2/S3 bipartite recombinant.

CONCLUSIONS

Detection of recombinant circulating vaccine-derived PVs (cVDPVs) is crucial, since increased transmissibility over that of the parental Sabin strains has been proposed to be the result of recombination events.

SIGNIFICANCE AND IMPACT OF THE STUDY

Importation of recombinant cVDPVs evolved derivatives pose a serious threat to public health and environmental surveillance should be implemented during and after PVs eradication.

Effect of dietary oregano oil and alpha-tocopheryl acetate supplementation on iron-induced lipid oxidation of turkey breast, thigh, liver and heart tissues

Twenty-five 12-week-old turkeys randomly divided into five groups were given a basal diet, or a basal diet supplemented with 200 mg alpha-tocopheryl acetate/kg, or 100 mg oregano oil/kg or 200 mg oregano oil/kg, or 100 mg oregano oil plus 100 mg alpha-tocopheryl acetate/kg diet, for 4 weeks prior to slaughter. Breast, thigh, liver and heart tissues were subjected to iron-induced lipid oxidation, the extent of which was determined by third-order derivative spectrophotometry. Results showed that dietary oregano oil at the inclusion level of 200 mg oregano oil/kg diet was more effective in delaying lipid oxidation compared with the inclusion level of 100 mg/kg, but equivalent to the inclusion of 200 mg alpha-tocopheryl acetate/kg diet, which in turn was inferior to the combined inclusion of 100 mg oregano oil plus 100 mg alpha-tocopheryl acetate/kg, which was superior to all dietary treatments. Thigh tissue was more susceptible to oxidation than breast tissue, although it contained alpha-tocopherol at higher concentrations. Also, lipid oxidation in heart was relatively high, although it contained the highest alpha-tocopherol levels. This indicates that tissue alpha-tocopherol is one important factor influencing the level of lipid oxidation, but the distribution of lipids, iron and oregano oil in tissues must also be taken into consideration. Tissue alpha-tocopherol levels responded to dietary intake of 30-200 mg alpha-tocopheryl acetate/kg in the order heart > liver > thigh > breast. Breast, thigh and heart tissues from the oregano groups presented significantly (p < 0.05) higher levels of alpha-tocopherol compared with the control, the increase being positively correlated with the supplementation level. The increased levels of alpha-tocopherol in these tissues indicated that the dietary oregano oil exerted a protective action on alpha-tocopherol.

Blockade of Kupffer cells by gadolinium chloride reduces lipid peroxidation and protects liver from ischemia/reperfusion injury

BACKGROUND/AIMS

The implication of lipid peroxidation in the inhibitory effect of GdCl3 (gadolinium chloride) on Kupffer cells activation has not been extensively investigated. The aim of this study was to examine the effect of GdCl3 inhibition of Kupffer cells activation on lipid peroxidation after severe total hepatic ischemia/reperfusion.

METHODOLOGY

Male Wistar rats (n = 40) were randomly divided into a sham-operation group, a control ischemia/reperfusion group, and two ischemia/reperfusion groups pretreated with GdCl3 (10 mg and 20 mg/kg bw intravenously, 48 and 24 h prior to operation). Following 60 min of total hepatic ischemia and 120 min of reperfusion, the rats were sacrificed, and liver samples were taken for determination of malondialdehyde and light microscopy examination. Blood samples were also taken for assay of aspartate and alanine transaminase. Additional animals (n = 60) were followed up for a 7-day survival rate determination.

RESULTS

Ischemia/reperfusion decreased the survival rate to 13.3%, increased (p < 0.001) the levels of aspartate and alanine transaminase in serum to 2387 +/- 75 and 2157 +/- 87 IU/L, respectively, and increased (p < 0.001) malondialdehyde levels in liver to 1.609 +/- 0.096 nmoles/g compared with 1.164 +/- 0.060 in the sham operation group. Pretreatment with GdCl3 increased the survival rate to 60%, and decreased (p < 0.001) the levels of aspartate transaminase in serum to 1549 +/- 66 and 1496 +/- 55 IU/L, the levels of alanine transaminase in serum to 1302 +/- 48 and 1305 +/- 63 IU/L, and the levels of malondialdehyde in liver to 1.132 +/- 0.034 and 1.149 +/- 0.57 nmoles/g for the lower and the higher doses of GdCl3, respectively. Histological examination showed protection of liver parenchyma in the animals treated with GdCl3.

CONCLUSIONS

Experimental data suggest that GdCl3 inhibition of Kupffer cells activation protects liver from ischemia/reperfusion injury by a mechanism that reduces lipid peroxidation.

PLP Induced Inhibition of Thymidylate Synthase Activity in T Lymphocytes

The present study was undertaken in order to examine whether pyridoxine may be used as an inhibitor of thymidylate synthase, and thus, as an antiproliferative agent. It has already been shown by others that pyridoxal phosphate binds thymidylate synthase in vitro. Phytohemagglutinin-stimulated T lymphocytes were cultured in the presence of pyridoxine in various concentrations. Enzyme activity was measured in supernatants of sonicated cell extracts. Our results show that pyridoxine effectively inhibits thymidylate synthase (up to 60–70%) and therefore DNA synthesis (up to 42%) and cell division. We also present evidence that pyridoxine must be phosphorylated to PLP in order to exert its inhibitory effect. Our results suggest that pyridoxal phosphate, in addition to its function as a coenzyme, may have a role in regulating DNA synthesis through modulation of thymidylate synthase activity. Our findings also indicate that pyridoxal phosphate might be tested for its potential immunosuppressive and/or chemotherapeutic action, alone or in combination with other antiproliferative agents.

Microwave saturation of the Rydberg States of electrons on helium

We present measurements of the resonant microwave excitation of Rydberg energy levels for surface-state electrons on superfluid helium. The temperature-dependent contribution to the linewidth gamma(T) agrees with theoretical predictions and is very small below 700 mK, in the ripplon scattering regime. Absorption saturation and power broadening were observed as the fraction of electrons in the first excited state was increased to 0.49, close to the thermal excitation limit of 0.5. The Rabi frequency Omega was determined as a function of microwave power. High values of the ratio Omega/gamma confirm this system as an excellent candidate for creating qubits.

Photochemical and pharmacological evaluation of 7-nitroindolinyl-and 4-methoxy-7-nitroindolinyl-amino acids as novel, fast caged neurotransmitters

Reagents capable of rapid and efficient release of neuroactive amino acids (L-glutamate, GABA and glycine) upon flash photolysis of thermally stable, inert precursors have been elusive. 7-Nitroindolinyl (NI)-caged and 4-methoxy-7-nitroindolinyl (MNI)-caged compounds that fulfil these criteria are evaluated here. These caged precursors are highly resistant to hydrolysis. Photolysis is fast (half time< or =0.26 ms) and the conversion achieved with a xenon flashlamp is about 15% for the NI-caged L-glutamate and about 35% for the MNI-caged L-glutamate. A procedure is described for calibration of photolysis in a microscope-based experimental apparatus. NI-caged L-glutamate itself showed no agonist or antagonist effects on AMPA and NMDA receptors in cultured neurones, and had no effect on climbing fibre activation of Purkinje neurones. A control compound with identical photochemistry that generated an inert phosphate upon photolysis was used to confirm that the intermediates and by-products of photolysis have no deleterious effects. MNI-caged L-glutamate is as stable and fast as NI-caged L-glutamate and similarly inert at glutamate receptors, but about 2.5 times more efficient. However, NI-caged GABA is an antagonist at GABA(A) receptors and NI-glycine an antagonist at glycine receptors. The results show the utility and limitations of these fast and stable caged neurotransmitters in the investigation of synaptic processes.

Observation of dynamical ordering in a confined Wigner crystal

We present measurements of the conduction of nondegenerate free electrons along a low-dimensional channel at low temperatures, using surface-state electrons on liquid helium in novel microelectronic devices. Above 1 K, the electrons form an ideal classical Drude conductor. Below 1 K, Coulomb interactions produce electronic spatial order, leading to strong non-Ohmic effects and negative differential conductivity. Evidence is presented for self-organized current filaments in the channel, created by a nonequilibrium phase transition. Periodic conductance oscillations suggest an anisotropic spatial order with lines of electrons along the channel edges.

Severe total hepatic ischemia and reperfusion: relationship between very high alpha-tocopherol uptake and lipid peroxidation

Reperfusion injury of the liver occurs in liver transplantation and in major hepatectomies. It triggers a severe oxidative stress that leads to increased lipid peroxidation. In our study we examined the effect of parenteral supranutritional administration of alpha-tocopherol, a vitamin that plays a key role in the endogenous antioxidant system, to rats subjected to severe ischemia/reperfusion (I/R) injury of the liver. alpha-Tocopherol was administered to the animals at doses of 30 and 300 mg/kg bw, whereas total hepatic ischemia was induced for 60 min followed by 120 min reperfusion. Tissue and blood samples were collected for malonyldialdehyde (MDA) and serum alpha-tocopherol assay, respectively. In the sham operation group, mean MDA level in liver was 1.14 nmole/g wet tissue in the control subgroup, and 1.01 or 0.74 nmole/g wet tissue in the subgroups given 30 or 300 mg/kg alpha-tocopherol. In the I/R group, mean MDA level was 1.57 nmole/g wet tissue in the control subgroup, and 0.97 and 0.77 nmole/g wet tissue in the subgroups given 30 or 300 mg/kg alpha-tocopherol. Mean levels of alpha-tocopherol in serum (mumole/l) were 10.20 and 1.80 in the control subgroups, 25.28 and 11.25 in the subgroups treated with 30 and 300 mg/kg bw of alpha-tocopherol, and 31.00 and 13.02 in the subgroups treated with 30 and 300 mg/kg bw of alpha-tocopherol, within the sham-operation and I/R groups, respectively. A significant decrease of MDA accompanied by a significant increase of serum alpha-tocopherol was documented in the alpha-tocopherol-treated rats within both groups. Ischemia/reperfusion triggered a significant increase of the MDA level in the liver of the rats not treated with alpha-tocopherol as compares with the treated animals.

The conductance underlying the parallel fibre slow EPSP in rat cerebellar Purkinje neurones studied with photolytic release of L-glutamate

1. Tetanic stimulation of parallel fibres (PFs) produces a slow EPSP (sEPSP) or slow EPSC (sEPSC) in Purkinje neurones (PNs), mediated by type 1 metabotropic glutamate receptors (mGluR1). The conductance change underlying the sEPSP was investigated with rapid photolytic release of L-glutamate from nitroindolinyl (NI)-caged glutamate with ionotropic glutamate receptors blocked, and showed a slow mGluR1-activated cation channel. 2. In cerebellar slices rapid photolytic release (t (1/2) < 0.7 ms) of 7--70 microM L-glutamate on PNs voltage clamped at -65 mV activated first a transient inward current, peaking in 8 ms, followed by a slow inward current with time course similar to the PF sEPSP, peaking at -1 nA in 700 ms. 3. The initial current was inhibited by 300 microM threo-hydroxyaspartate (THA) and did not reverse as the potential was made positive up to +50 mV, suggesting activation of electrogenic glutamate uptake. 4. The slow current was inhibited reversibly by 1 mM (R,S)-MCPG or the non-competitive mGluR1 antagonist CPCCOEt (20 microM), indicating activation of metabotropic type 1 glutamate receptors. The mGluR current was associated with increases of input conductance and membrane current noise, and reversed close to 0 mV, indicating activation of channels permeant to Na(+) and K(+). 5. The sEPSC was not blocked by Cd(2+), Co(2+), Mg(2+) or Gd(3+) ions, by the inhibitor of hyperpolarisation-activated current (I(H)) ZD7288, or by the purinoceptor inhibitor PPADS. Activation was not affected by inhibitors of phospholipase C (PLC) or protein kinase C (PKC), nor mimicked by photorelease of InsP(3) or Ca(2+). The results show that mGluR1 in PNs produces a slow activation of cation-permeable ion channels which is not mediated by PLC activation, Ca(2+) release from stores, or via the activation of PKC.

Diplopia as a complication of local anesthesia: a case report

Diplopia caused by local anesthesia at the superior posterior alveolar nerve for the removal of the maxillary third molar is a rare complication. The diplopia is due to facial palsy of the oculomotor muscles of the globe. This paper describes the case of a 22-year-old woman, in whom diplopia was observed after an overall uncomplicated removal of the semi-impacted third molar. Possible causes of the anesthetic effects are reported. The most accepted explanation is that the anesthetic diffuses on the abducent nerve in the cavernous sinus. The necessary actions that the dental surgeon must perform are reported.

Concurrent multivessel stenting in a patient with multifocal arterial disease

PURPOSE

To report the concurrent endovascular treatment of multiple stenoses in different vascular territories.

METHODS AND RESULTS

A 45-year-old male presented with an aortic arch syndrome, renovascular hypertension, and Leriche syndrome. Intra-arterial digital arteriography disclosed occlusion of the left subclavian artery and stenoses in the left common carotid artery (CCA), the right CCA at the bifurcation, the left renal artery, and both iliac arteries. In a single procedure, the patient received 5 stents in 2 carotid, 1 renal, and 2 iliac arteries. At 3-month follow-up, color flow duplex imaging confirmed continued patency of all stented arteries.

CONCLUSIONS

This case illustrates the feasibility, safety, and cost effectiveness of treating multivessel stenoses using a single-session endovascular approach executed by experienced interventionists.

Lipid peroxidation of rat myocardial tissue following daunomycin administration

Daunomycin-induced cardiotoxicity has been regarded to be the result of oxygen-mediated lipid peroxidation of cell membranes. The aim of the present work was to evaluate the extent of lipid peroxidation in rat heart after administration of this anticancer drug and, further, to examine possible activation of some endogenous antioxidant defense systems. Myocardial tissue from both control and drug-treated rats was tested for lipid peroxidation using a selective third-order derivative method that is based on the analysis of the free malondialdehyde produced. Determination of reduced/oxidized glutathione levels and measurement of the activity of DT-diaphorase, glutathione-S-transferase, glutathione reductase, glucose-6-phosphate dehydrogenase and NADPH-cytochrome P-450 reductase were also carried out using literature methods. Significant increase of malondialdehyde content, and DT-diaphorase and glutathione-S-transferase activities were found in myocardial tissue from daunomycin-treated rats. On the other hand, reduced and oxidized glutathione levels were significantly decreased while the activity of glutathione reductase, glucose-6-phosphate dehydrogenase and NADPH-cytochrome P-450 reductase remained unchanged after daunomycin administration. The results of the present study give further evidence that daunomycin can induce lipid peroxidation in heart. However, additional experimentation is needed in order to delineate the molecular details of this process as well as of the mechanisms evolved to limit it.

Hepatic tissue microcirculation, oxygenation and energy charge in ischemia-reperfusion subjected cirrhotic rat liver

BACKGROUND/AIMS

The hemodynamic disturbances in the cirrhotic liver following severe variceal bleeding and subsequent restoration by blood transfusion is an ischemia/reperfusion injury event which represents the clinical situation of liver dysfunction. Therefore, the aim of this study was to evaluate the microcirculation, oxygenation and energy charge of the cirrhotic rat liver after ischemia/reperfusion.

METHODOLOGY

In eight carbon tetrachloride-induced cirrhotic rats and an equal number of controls subjected to 30 minutes of ischemia and 60 minutes of reperfusion by hepatoduodenal ligament clamping, the following parameters were assessed: hepatic microcirculation by laser-Doppler fluxmetry, hepatic tissue oxygenation by a Clark-type electrode, hepatic energy charge by tissue sampling and adenine-nucleotides determination by means of high-performance liquid chromatography.

RESULTS

At baseline, liver microcirculation was found to be significantly decreased in the cirrhotics versus controls groups. Ischemia led to a reduction in both groups, while reperfusion improved microcirculation, but not to the baseline level. Oxygenation was reduced during ischemia and restored after reperfusion in both groups. Hepatic energy charge was reduced in the cirrhotics versus controls at baseline, and significantly decreased during ischemia in both groups. At reperfusion, a further reduction was found in the cirrhotic group, while in the control group it was restored to baseline.

CONCLUSION

Hepatic microcirculation, oxygenation and energy charge are subjected to different degrees of diminution after ischemia/reperfusion in the cirrhotic rat liver.

Human leukocyte antigen system in clozapine-induced agranulocytosis

Forty-three schizophrenic patients participating in this study were serotyped for human leukocyte antigens (HLA-A, -B, -C, -DR, -DQ antigens). Thirty-six of them were hospitalised in two state mental hospitals and 7 in our general hospital, psychiatric unit. The patients from our unit were typed for HLA before commencing clozapine treatment whereas the patients from state hospitals were typed after commencing treatment. Three out of 43 patients developed agranulocytosis. One had a combination of both 'high-risk' haplotypes (HLA-B16(38,39), DR4, DQ3 and HLA-DR2, DQ1), another had HLA-DR2, DQ1, whereas the last had a totally different haplotype. Between non-agranulocytic patients 1 was found to carry the HLA-B16(38,39), DR4, DQ3 haplotype and 14 (out of 40) had the HLA-DR2, DQ1. Taking into account other factors supposed to be involved (a noxious metabolite, and the presence of a humoral cytotoxic factor) we must admit that despite the finding of a high-risk haplotype in Jewish populations there are other aspects of this question awaiting clarification.