Clinical Evidence of Retrograde Axonal Growth in Chronic Brachial Plexus Injury.

Nerve axons grow from proximal to distal after axonometric injury; however, they have been seen to regenerate via alternate routes, with some also demonstrating retrograde growth in neuromas. We present the case of a 33-year-old male with a 16-year-old traumatic brachial plexus injury presenting with neuropathic pain and isolated spontaneous recovery. Following a successful pre-operative anaesthetic block, a neurectomy of the median and ulnar nerves was planned for pain relief. Intraoperatively, median nerve stimulation resulted in muscle contractions in the pectoralis major (PM) and extensor carpi radialis brevis (ECRB). This was confirmed by electrical and mechanical stimuli. Histological analysis confirmed the presence of viable axons in the median nerve despite no distal nerve function. Post-surgery motor activity was preserved. A plausible explanation for the intraoperative observations, suggesting neural connectivity between the median nerve and PM and ECRB, would be retrograde growth into various nerve pathways. Alternative explanations such as axonal bifurcation, light anaesthesia, or anatomical variations were considered but the evidence favoured retrograde axonal regrowth. These findings challenge conventional understanding and offer potential new approaches to nerve reconstruction.

Characterisation of the antioxidant effects of Aesculus hippocastanum L. bark extract on the basis of radical scavenging activity, the chemiluminescence of human neutrophil bursts and lipoperoxidation assay.

OBJECTIVES: Oxidative stress is increasingly recognised as a pivotal factor that plays a number of roles in the inflammatory response to environmental signals. It has been claimed that Aesculus hippocastanum extracts have antioxidant and anti-inflammatory activity, but these claims are mainly based on the results of chemical reactions and folk-medicine. MATERIALS AND METHODS: The aim of this study was to examine whether a bark extract of Aesculus hippocastanum interferes with reactive oxygen/nitrogen species (ROS/RNS) during the course of human neutrophil respiratory bursts, and to establish the lowest concentration at which it still has antioxidant activity by means of luminol amplified chemiluminescence (LACL). We also studied its ability to counteract lipid peroxidation (LPO) in human cells. Before investigating its antioxidant effects on human cells, we analysed its scavenging activity against ABTS*+, hydroxyl radical, superoxide anion, and Fremy's salt (those last three by means of electron paramagnetic resonance (EPR) spectrometry). RESULTS: The extract of Aesculus hippocastanum exerted its anti-ROS/RNS activity in a concentration-dependent manner with significant effects being observed for even very low concentrations: 10 microg/ml without L-Arg, and 5 microg/ml when L-Arg was added to the fMLP test. The LPO assay confirmed these results, which were paralleled by the EPR study. CONCLUSIONS: These findings are interesting for improving the antioxidant network and restoring redox balance in human cells, and extend the possibility of using plant-derived molecules to antagonise the oxidative stress generated in living organisms when the balance is in favour of free radicals as a result of the depletion of cell antioxidants.

Comparison of cardioprotective abilities between the flesh and skin of grapes.

Recent studies have documented that grapes and grape juices are equally cardioprotective as red wine. The existing reports implicate that the skin and seeds of the grapes containing polyphenolic antioxidants are instrumental for the cardioprotective properties of grapes. The present study examines if the flesh of grapes also possesses any cardioprotective abilities. Three groups of randomly selected rats were fed, water only (control), flesh of the grapes (2.5 mg/kg b. wt.) or the skins (2.5 mg/kg b. wt.) for 30 days. At the end of the 30 days, isolated perfused hearts were made ischemic for 30 min followed by 2 h of reperfusion in the working mode. The results demonstrated that both flesh and skin of the grapes could protect the hearts from ischemic reperfusion injury as evidenced by improved postischemic ventricular recovery and reduced myocardial infarct size. High performance liquid chromatography (HPLC) revealed that skin and flesh contained comparative amounts of glucose, fructose, tartaric acid, malic acid, shikimic acid, and trans-caftaric acid. In addition, the flesh contained reduced amounts (compared to skin) of cis-coutaric, trans-coutaric, caffeic, p-coumaric, cinnamics, and catechin/epicatechin. Total polyphenolic index was also lower in flesh compared to skin. The anthocyanins were present exclusively in the skin. Electron paramagnetic resonance (EPR) spectrometry of hydroxy radicals indicated that both flesh and skins possessed equal amount of ROS scavenging activities. Total malonaldehyde content in the heart was reduced comparatively with either flesh or skin. The results indicate for the first time that the flesh of grapes are equally cardioprotective as skin, and antioxidant potential of skin and flesh of grapes are comparable with each other despite of the fact that flesh does not possess any anthocyanin activities.

Evaluation of carnitine, acetylcarnitine and isovalerylcarnitine on immune function and apoptosis.

The pool of different carnitine derivatives is formed by carnitine, acetylcarnitine, propionylcarnitine and isovalerylcarnitine. Isovalerylcarnitine is a compound performing activities that differ from those of the other carnitine esters. Its activity on proteolytic enzymes and on the calpain system has been demonstrated in the past. Both the calpain and the caspase systems belong to the protease family and lead to cytochrome activation and apoptosis. The two systems can interact to promote apoptosis. In view of this proapoptotic activity of isovalerylcarnitine, studies were carried out to ascertain whether this carnitine derivative influences cell-reaction processes associated with apoptosis. U937 leukemic cells were selected for these studies because they are a well-established model for the assessment of cellular immune responses. In addition to nuclear morphologic alterations produced by apoptosis that can be detected by specific histochemical and microscopic methods, we also took other cell functions into consideration, such as phagocytosis, cell killing and cell growth, which are indices of immune function related to apoptosis. Unlike reference carnitine forms, isovalerylcarnitine produced an early and marked increase in phagocytosis and also an increase in cell killing. Cell proliferation was reduced. The hypothesis is set forth that isovalerylcarnitine may be a caspase-activating, proapoptotic factor that resembles various anticancer agents, which induce early apoptosis that coincides with early activation of caspase. This hypothesis is supported by the ability of isovalerylcarnitine to induce early phagocytosis and cell killing.

The red wine antioxidant resveratrol protects isolated rat hearts from ischemia reperfusion injury.

The consumption of red wine has been reported to impart a greater benefit in the prevention of coronary heart disease than the consumption of other alcoholic beverages. This beneficial effect is increasingly being attributed to certain antioxidants comprising the polyphenol fraction of red wine such as transresveratrol. In the present study, we investigated the potential cardioprotective effects of resveratrol in the face of ischemia reperfusion (I/R) injury. Isolated perfused working rat hearts after stabilization were perfused with Krebs-Henseleit Bicarbonate buffer (KHB) either in the presence or absence of transresveratrol (RVT) at a concentration of 10 microM for 15 min prior to subjecting them to 30 min of global ischemia followed by 2 h of reperfusion. Left ventricular functions were monitored at various timepoints throughout the reperfusion period to assess the extent of postischemic recovery in comparison with baseline values. Coronary perfusate samples were also collected to determine malonaldehyde (MDA) levels. The results demonstrated that RVT exhibited significant myocardial protection. This was evidenced by improved recovery of post-ischemic ventricular function including developed pressure and aortic flow as compared to the control group (KHB). Values for developed pressure in the RVT-treated group were significantly higher than those in the control group throughout the reperfusion period (71.09+/-4.88 mm Hg vs. 58.47+/-3.88 mm Hg, 68.87+/-5.07 mm Hg vs. 49.74+/-2.65 mm Hg and 51.67+/-3.95 mm Hg vs. 30.50+/-4.80 mm Hg at reperfusion timepoints R-15, R-60, and R-120, respectively). From R-30 onwards, aortic flow was markedly higher in the RVT treated group as compared with the control group, the differences being most significant at R-90 (32.45+/-2.19 ml/min vs. 19.83+/-1.62 ml/min) and R-120 (27.15+/-2.27 ml/min vs. 14.10+/-1.69 ml/min). In contrast to the KHB treated group, the RVT-treated group displayed significant reduction in MDA formation especially in the immediate early reperfusion period (63.71+/-8.19 pM/ml vs. 130.86+/-4.76 pM/ml, 63.84+/-15.62 pM/ml vs. 156.99+/-18.93 pM/ml, 71.29+/-2.80 pM/ml vs. 129.5+/-10.30 pM/ml and 56.25+/-5.79 pM/ml vs. 127.99+/-3.50 pM/ml at timepoints R-1, R-3, R-5, and R-7, respectively) indicating a reduction in I/R injury related oxidative stress. Infarct size was markedly reduced in the RVT group when compared with the control group (10.57+/-0.35% vs. 36.27+/-5.28%). In vitro studies revealed RVT to be a potent scavenger of peroxyl radicals suggestive of a probable mechanism involved in the protective ability of RVT. The results of this study indicate that resveratrol possesses cardioprotective effects which may be attributed to its peroxyl radical scavenging activity.

Activity in vitro of resveratrol on granulocyte and monocyte adhesion to endothelium.

BACKGROUND: Resveratrol is a phytoalexin present in red wine. It has been shown to protect LDL from peroxidative degradation. OBJECTIVE: In consideration of the low plasma concentration of orally adsorbed resveratrol (which is insufficient for antioxidant protection of LDL), we studied another effect of the compound. DESIGN: Because resveratrol is a tyrosine kinase inhibitor like other members of the tyrphostin family, we hypothesized that it has the ability to modify intracellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1) expression by stimulated endothelial cells. We studied the ability of resveratrol to inhibit such adhesion molecule expression and to block the adhesion of monocytes and granulocytes to endothelial cells. RESULTS: We showed that resveratrol, at concentrations as low as 1 micromol/L and 100 nmol/L, significantly inhibited ICAM-1 and VCAM-1 expression by tumor necrosis factor alpha (TNF-alpha)-stimulated human umbilical vein endothelial cells and lipopolysaccharide-stimulated human saphenous vein endothelial cells (HSVEC), respectively. In addition, we showed that resveratrol induced a significant inhibition in the adhesion of U937 monocytoid cells to lipopolysaccharide-stimulated HSVEC. Such inhibition was comparable with that obtained when anti-VCAM-1 monoclonal antibody was used instead of resveratrol. Resveratrol also significantly inhibited the adhesion of neutrophils to TNF-alpha-stimulated NIH/3T3 ICAM-1-transfected cells, whereas neutrophils activated by formyl-methionyl-leucyl-phenylalanine did not significantly modify adhesion to NIH/3T3 ICAM-1-transfected cells. CONCLUSIONS: Our results indicate activity of resveratrol on endothelial cells and a new interpretation of an effect independent of its antioxidant function.

Conformational effects on the activity of drugs. 5. Pharmacological properties of 2-(p-nitrophenyl)-4-isopropylmorpholine, a cyclic analog of INPEA.

2-(p-Nitrophenyl)-4-isopropylmorphine (V), an analog of 1-(p-nitrophenyl)-2-isopropylaminoethanol (INPEA, I) in which the OCHCHN chain of I is locked in a morpholine ring, loses the beta-receptor blocking activity of I on various isolated preparations. The same ineffectiveness is observed in the O-methyl (II), N-methyl (III), and N,O-dimethyl analog (IV) of I. However, some other properties which are present in I, such as inhibitory effect on acetylcholine or on 5-HT, intrinsic alpha-sympathomimetic activity, and potentiation of catecholamines, are maintained; this demonstrates a complete dissociation of these effects from beta-receptor blockade. The interactions with the alpha-adrenoceptors and with the uptake mechanism are discussed on the basis of the structure-activity relationship between I and its analogs II-V.

Interaction of anthracycline antibiotics with human neutrophils: superoxide production, free radical formation and intracellular penetration.

Human neutrophils exposed to 10(-4) M doxorubicin and the derivatives epirubicin and thepirubicin revealed a different intracellular penetration and distribution pattern as demonstrated by fluorescence microscopy and fluorimetric determination of drug intracellular concentration. While doxorubicin was found to be a potent inducer of superoxide generation from resting cells, epirubicin exhibited less superoxide-inducing power. Thepirubicin on the contrary did not show any superoxide-inducing effect. Moreover the anthracyclines tested all inhibited the phorbol ester-stimulated chemiluminescent response to the same extent, which suggested a common target for the drug action. Anthracycline-stimulated superoxide production seems to correlate with the cardiotoxic effects. The most cardiotoxic drug, doxorubicin, is the most potent inducer of superoxide generation, while epirubicin, which is less cardiotoxic, has a relatively limited effect on superoxide production. Thepirubicin which has been shown not to induce delayed cardiomyopathy has no effect on superoxide release from the cells.

Opportunities in nutraceuticals.

The 3rd Vitafoods International Conference and Exhibition, held May 3-5, 2000, in Geneva, Switzerland, presented the latest findings and opportunities in the sector of nutraceuticals, dietary supplements and functional food. In addition to acetyl-L-carnitine and gamma-linolenic acid, the following products were highlighted: probiotics, proanthocyanadin, lutein and pectins. The future of this field will require that nutraceutical firms promote research at both the experimental and the clinical levels to convince medical doctors of the efficacy and health-promoting effects of these products.

Anti-apoptotic effect of trans-resveratrol on paclitaxel-induced apoptosis in the human neuroblastoma SH-SY5Y cell line.

Paclitaxel, an anticancer drug, induces apoptosis in human neuroblastoma cell line SH-SY5Y. The addition of trans-resveratrol, a natural antioxidant present in grapes and red wine, to SH-SY5Y cultures exposed to paclitaxel significantly reduces cellular death. The neuroprotective action of trans-resveratrol is due neither to its antioxidant capacity nor to interference with the polymerization of tubulin induced by paclitaxel. However, trans-resveratrol is able to inhibit the activation of caspase 7 and degradation of poly-(ADP-ribose)-polymerase which occur in SH-SY5Y exposed to paclitaxel. Resveratrol, therefore, exerts its anti-apoptotic effect by modulating the signal pathways that commit these neuronal-like cells to apoptosis.

Resveratrol-induced activation of the mitogen-activated protein kinases, ERK1 and ERK2, in human neuroblastoma SH-SY5Y cells.

Phosphorylation of the mitogen-activated protein (MAP) kinases, extracellular signal-regulated kinase 1 (ERK1) and extracellular signal-regulated kinase 2 (ERK2), induced by resveratrol, a natural antioxidant present in grapes and wine, has been studied in vitro on undifferentiated and differentiated (induction by retinoic acid) SH-SY5Y human neuroblastoma cells. In undifferentiated cells resveratrol 1 microM induced phosphorylation of ERK1 and ERK2, which was already evident at 2 min, peaked at 10 min and persisted at 30 min. A wide range (from 1 pM to 10 microM) of resveratrol concentrations were able to induce phosphorylation of ERK1 and ERK2, while higher concentrations (50-100 microM) inhibited MAP kinases phosphorylation. In retinoic acid (RA) differentiated cells resveratrol (1 microM) induced an evident increase in ERK1 and ERK2 phosphorylation. This study demonstrates that resveratrol, even at very low concentrations, may have a biological effect on neuron-like cells.

Effects of 4'-O-tetrahydropyranyl-doxorubicin on isolated perfused rat heart and cardiac mitochondrial cytochrome C oxidase activity.

The acute cardiac effects of the antitumour anthracycline 4'-O-tetrahydropyranyl-doxorubicin (THP) were studied on isolated, perfused, spontaneously beating rat hearts and on cardiac mitochondrial cytochrome c oxidase activity. Perfusion for 1 hour with 2.5 or 5.0 micrograms/ml of THP was associated with a marked widening of the QRS complex and the S alpha T segment, as well as with a reduction of the R- and T-wave amplitude, the heart rate, the isometric systolic tension and the coronary flow. Heart perfusion with equimolar doses of doxorubicin (2.2 or 4.4 micrograms/ml) induced a significant enlargement of the SaT segment and a reduction in the heart rate and the coronary flow. Both anthracyclines inhibited the cytochrome c oxidase activity in a dose-dependent manner; however, THP exerted a significant inhibition at concentrations higher than doxorubicin (20 microM). Results demonstrate that THP induces a higher degree of acute cardiotoxicity on isolated rat hearts compared with doxorubicin. The reduced inhibitory effect of THP on the cytochrome c oxidase activity of isolated heart mitochondria is consistent with the lower degree of chronic cardiotoxicity displayed by THP in animals and humans.

Prevention and control of surgical infections.

Surveillance and control of hospital infections are two particularly important aspects of the surgical ward, and great activity is necessary in the identification and the elimination of the risk factors whenever possible. Today the rational use of antibiotics, in both the prevention and treatment of infections, should be used to avoid or limit nosocomial infections, and it is as important as the use of disinfectants. Cefotetan has been studied in different surgical specialties in prophylaxis and treatment of postoperative infections for its particularly broad spectrum of activity, covering both aerobic and anaerobic organisms, and for the very low incidence of side-effects. In general surgery, Cefotetan has proved able to reduce not only the occurrence of surgical wound infections, but also that of postoperative infections of the genitourinary system.

Inhibition of histamine release and pressure increase induced by endothelin (ET-1) in isolated rat kidneys treated with propionyl carnitine.

Endothelin-1 (ET-1) is an amino peptide produced by endothelial cells with a potent vasoconstrictor activity; this effect is regulated by a release of other endogenous vasal factors. Recent studies have demonstrated that endothelin is capable of releasing from different tissues, and particularly from perfused organs such as spleen and kidney, many vasal factors and prostanoids. The present study investigates whether perfusion with a solution of endothelin-1 in rat isolated kidney can induce the release of histamine, another vasal factor (until now not investigated in relation with endothelin-1) and whether treatment with propionyl carnitine, a compound with vasoprotecting activity, inhibits this release. This research demonstrates that histamine released by rat kidney perfused with endothelin is lowered if previously treated with propionyl carnitine. This effect of propionyl carnitine can be considered to be another important factor in a complex mechanism involved in its vasoprotective and cardiovascular action.

The potentiating effect of propionyl carnitine on prostacycline prevention of thrombosis induced by endothelin (ET-1) and K-carrageenin.

The aim of the present experiments was to ascertain whether prostacycline could exercise a protective effect against the formation of thrombosis in the rat tail induced by endothelin and K-carrageenin and to compare the effect of prostacycline with that of carnitine and propionyl carnitine. Both prostacycline and propionyl carnitine exhibited a similar protective effect on this experimental model. A combined protective effect of prostacycline administered with carnitine was also observed and a possible interaction between these two substances is proposed.

Plasma and tissue resveratrol concentrations and pharmacological activity.

In this study a comparison was made between results obtained from resveratrol dosages which have been shown to be pharmacologically active, in vitro and in vivo, and the results of plasma and tissue concentrations obtained after a single administration or after prolonged administration of red wine with a known resveratrol content. The dosages used by different investigators in the tests are very different and, in general, rather high in relation to the concentrations which are found in wine or grapes. The results of our tests on platelet aggregation confirm that even with modest dosages of resveratrol, a pharmacological effect can be observed, and that these dosages can be compatible with the resveratrol concentrations obtained after oral administration. The data obtained from these tests on animals can lead to the conclusion that even an average drinker of wine can, particularly in the long term, absorb a sufficient quantity of resveratrol to explain the beneficial effect of red wine on health, which has been observed in epidemiological studies carried out in populations whose daily diet includes the drinking of wine.

Protective role of propionyl carnitine in vascular disorders experimentally induced by endothelin (ET-1) serotonin and K-carrageenin.

Propionyl carnitine, a derivative of carnitine, has metabolic and cardiovascular effects similar to carnitine but with more pronounced peripheral haemodynamic activity. In these experiments we propose to prove that the administration of propionyl carnitine could prevent the experimental tail thrombosis in the rat induced by endothelin (ET-1), serotonin and K-carrageenin. In this new test of experimental thrombosis, propionyl carnitine was able to reduce the extent of tail thrombosis in a more significant manner than that of carnitine. A possible explanation of this antithrombotic effect of propionyl carnitine is its capacity to counteract the vasoconstrictor activity of endothelin modulating the release of prostanoids induced by endothelin itself.

Thrombosis induced by endothelin (ET-1) and carrageenin in rats treated with indomethacin and propionyl carnitine.

Propionyl carnitine can prevent endothelin and carrageenin-induced thrombosis in the rat's tail. This protective action of propionyl carnitine is probably related to its capacity to increase the synthesis of PGI2 prostaglandins and, subsequently, the amount of prostaglandins released by endothelin. Indomethacin, a well known prostanoid synthesis blocker, is unable to inhibit the protective activity of propionyl carnitine on endothelin-induced thrombosis after prolonged propionyl carnitine administration, but only a part of this protective activity after propionyl carnitine acute administration. Subsequently, other factors in addition to prostanoids seem to be involved in protective mechanisms of propionyl carnitine on endothelin-induced thrombosis.

Stability of resveratrol over time and in the various stages of grape transformation.

Research has been carried out with the purpose of verifying whether the resveratrol content in the skins or pomace of grapes stored for a long period of time without any particular protection with regard to temperature and humidity, could lead to a reduction of the content of this product detected at the beginning of the processing of grapes in vinification procedures. The dosages carried out both on the grape skin and on the pomace taken after fermentation and stored for a certain period of time, as well as on the products derived from alcoholic distillation, did not show the expected alterations in resveratrol content, considering their storage in bad environmental conditions for a long period of time. The results obtained confirm that resveratrol, unlike anthocyanins and other polyphenols, is stable and stores well over time.

Studies on the effects of anthracyclines on mitochondrial respiration in vitro.

Aclacinomycin, 4'-epi-doxorubicin and 4'-epi-tetrahydropyranyl-adriamycin, three novel anthraquinone derivatives under investigation for their antitumour activity, showed an inhibitory effect on the in vitro respiration of mitochondria from rat hearts. The inhibition proved to be concentration-dependent in the range 0.05 to 1.40 mM and both the NADH-oxidase and the succinate oxidase systems were affected to different extents. Among the compounds tested, 4'-epi-tetrahydropyranyl-adriamycin appeared to be the least powerful effector, requiring a significantly higher concentration for 50% inhibition of oxidation than doxorubicin and the other analogues examined.