Perivascular Fat Density and Contrast Plaque Enhancement: Does a Correlation Exist?

BACKGROUND AND PURPOSE

Inflammatory changes in the fat tissue surrounding the coronary arteries have been associated with coronary artery disease and high-risk vulnerable plaques. Our aim was to investigate possible correlations between the presence and degree of perivascular fat density and a marker of vulnerable carotid plaque, namely contrast plaque enhancement on CTA.

MATERIALS AND METHODS

One-hundred patients (76 men, 24 women; mean age, 69 years) who underwent CT angiography for investigation of carotid artery stenosis were retrospectively analyzed. Contrast plaque enhancement and perivascular fat density were measured in 100 carotid arteries, and values were stratified according to symptomatic (ipsilateral-to-cerebrovascular symptoms)/asymptomatic status (carotid artery with the most severe degree of stenosis). Correlation coefficients (Pearson ρ product moment) were calculated between the contrast plaque enhancement and perivascular fat density. The differences among the correlation ρ values were calculated using the Fisher r-to-z transformation. Mann-Whitney analysis was also calculated to test differences between the groups.

RESULTS

There was a statistically significant positive correlation between contrast plaque enhancement and perivascular fat density (ρ value = 0.6582, P value = .001). The correlation was stronger for symptomatic rather than asymptomatic patients (ρ value = 0.7052, P value = .001 versus ρ value = 0.4092, P value = .001).

CONCLUSIONS

There was a positive association between perivascular fat density and contrast plaque enhancement on CTA. This correlation was stronger for symptomatic rather than asymptomatic patients. Our results suggest that perivascular fat density could be used as an indirect marker of plaque instability.

Carotid Intraplaque-Hemorrhage Volume and Its Association with Cerebrovascular Events

BACKGROUND AND PURPOSE

Our aim was to assess the relationship between volume and percentage of intraplaque hemorrhage measured using CT and the occurrence of cerebrovascular events at the time of CT.

MATERIALS AND METHODS

One-hundred-twenty-three consecutive subjects (246 carotid arteries) with a mean age of 69 years who underwent CTA were included in this retrospective study. Plaque volume of components and subcomponents (including intraplaque hemorrhage volume) was quantified with dedicated software.

RESULTS

Forty-six arteries were excluded because no plaque was identified. In the remaining 200 carotid arteries, a statistically significant difference was found between presentation with cerebrovascular events and lipid volume (P = .002), intraplaque hemorrhage volume (P = .002), percentage of lipid (P = .002), percentage of calcium (P = .001), percentage of intraplaque hemorrhage (P = .001), percentage of lipid-intraplaque hemorrhage (P = .001), and intraplaque hemorrhage/lipid ratio (P = .001). The highest receiver operating characteristic area under the curve was obtained with the intraplaque hemorrhage volume with a value of 0.793 (P = .001), percentage of intraplaque hemorrhage with an area under the curve of 0.812 (P = .001), and the intraplaque hemorrhage/lipid ratio with an area under the curve value of 0.811 (P = .001).

CONCLUSIONS

Results of our study suggest that Hounsfield unit values <25 have a statistically significant association with the presence of cerebrovascular events and that the ratio intraplaque hemorrhage/lipid volume represents a strong parameter for the association of cerebrovascular events.

Radial access for percutaneous coronary procedure: relationship between operator expertise and complications

Objective

The aim of this study was to investigate (1) whether the learning curve of new catheterization laboratory operators increases the incidence of complications of transradial access during percutaneous coronary interventions and (2) whether manual compression with a two-step approach is safe and efficient for radial access hemostasis.

Methods

We performed a prospective study with all consecutive patients who underwent a coronary diagnostic or intervention procedure with radial access. The primary end point was a composite of pulseless radial artery of the wrist and hematoma evaluated after 24 hours. The secondary end point of efficacy was defined as the presence of bleeding or hematoma after 30 seconds.

Results

From March 2016 to June 2016, 150 consecutive patients, of whom 147 underwent coronary angiography and/or percutaneous coronary intervention through radial access, were included in the present study. The primary end point was present in 33%, but pulseless radial artery of the wrist was present only in 5.3%. We found that the incidence of primary end point was statistically different according to the number of puncture attempts, with a cutoff of two punctures with blood. The secondary end point of safety was present only in 4.7% of the cases.

Conclusion

Radial access is feasible and safe even if performed by training physicians. Manual compression with early evaluation after 30 seconds is a safe technique for managing the radial access after sheath removal.

C-C coupling between trinitrothiophenes and triaminobenzenes: zwitterionic intermediates and new all-conjugated structures

The reactions of 1,3,5-triaminobenzene derivatives with 2,3,4-trinitrothiophene and 2-bromo-3,4,5-trinitrothiophene gave new all-conjugated compounds bearing both an electron-withdrawing and an electron-donor moiety on the same unit. The reactions with 2,3,4-trinitrothiophene offered evidence, by NMR spectroscopy at low temperature, of the formation of new labile Wheland-Meisenheimer intermediates whereas at room temperature stable unexpected products derived from the attack of the nucleophile at C-4 with replacement of the nitro group were isolated. Their formation caused, in turn, the obtainment of a salt between 1-nitroso-2,4,6-triaminobenzenes and 2,4-dinitrothiophen-3-ol. The reactions with 2-bromo-3,4,5-trinitrothiophene produced in good yields the SNAr substitution product with the displacement of the bromide. All the new coupling products obtained are of applicative interest, considering the increasing concern for highly conjugated π-systems in solar energy conversion or optoelectronic devices.

New electron-donor and -acceptor architectures from benzofurazans and sym-triaminobenzenes: intermediates, products and an unusual nitro group shift

New all-conjugated C-C coupling products bearing both an electron-poor and an electron-rich aromatic moiety have been obtained from the reaction between sym-triaminobenzene derivatives and a series of isomeric chloro-nitrobenzofurazans. The reactions occur under mild reaction conditions, and in some cases a different behaviour depending on the presence, or not, of triethylamine was observed. From 1,3,5-tris(N-morpholinyl)benzene and 5-chloro-4-nitrobenzofurazan in the presence of triethylamine an unexpected product derived from the shift of the nitro group from C-4 to C-5 of the electrophile and bearing the nucleophile at position 4 was obtained. Moreover, from the coupling between 1,3,5-tris(N-pyrrolidinyl)benzene and 4-chloro-7-nitrobenzofurazan a highly stable Wheland intermediate was isolated.

Formaldehyde replacement with glyoxylic acid in semipermanent hair straightening: a new and multidisciplinary investigation

OBJECTIVE

Formaldehyde is an effective and popular semipermanent hair straightener, but the severe consequences for human health due to its toxicity have prompted the search for safer alternatives. Different carbonyl compounds, including glyoxylic acid, have recently been proposed as promising candidates. Despite the interest in this topic, there is a lack of information about the interactions between hair keratin and straightener agents. This study addresses this issue to gain new insights useful in the development of new products for safe, semipermanent hair deformation.

METHODS

The possible reactions occurring between carbonyl groups and nucleophilic sites on amino acid residues belonging to the keratin were investigated using as model compounds some aldehydes and amino acid derivatives. Raman and IR analyses on yak hair subjected to the straightening treatment with glyoxylic acid in different conditions were carried out. Scanning electron microscope (SEM) analyses were carried out on yak and curly human hair after each step of the straightening procedure.

RESULTS

The reactions between aldehydes and N-α-acetyl-L-lysine revealed the importance of the carbonyl electrophilicity and temperature to form imines. Raman and IR analyses on yak hair subjected to the straightening treatment evidenced rearrangements in the secondary structure distribution, conformational changes to the disulphide bridges, a decrease of the serine residues and formation of imines. It was also indicated that straightening produced major conformational rearrangements within the hair fibre rather than on the cuticle.

CONCLUSION

This investigation revealed the role played by the electrophilicity of the carbonyl on the straightener agent and of the temperature, closely related to the dehydration process. Raman and IR studies indicated the involvement of imine bonds and the occurrence of a sequence of conformational modifications during the straightening procedure. SEM analyses showed the effectiveness of the treatment at the cuticular level.

Prospective multicenter randomized trial comparing banding ligation with sclerotherapy of esophageal varices

BACKGROUND/AIMS

Endoscopic variceal banding ligation (EVL), first described by Stiegmann in 1988, is now an accepted alternative to sclerotherapy (EVS) for esophageal varices with previous bleeding. However, results are conflicting in terms of complications, eradication, recurrence, rebleeding and mortality rate. We aimed to compare EVL with EVS in a prospective randomized trial in patients with previous esophageal bleeding proved by endoscopy. End points were rebleeding rate and death during a short (eradication period) or long-term follow-up (> 1 year).

METHODOLOGY

One hundred patients (50 EVL, 50 EVS) were enrolled. Eradication rate, number of treatments needed to achieve eradication, recurrence of varices, rebleeding and complications were recorded and analyzed.

RESULTS

No differences were observed between the two groups regarding age, sex and Child class. One patient dropped out in the EVL group and 6 in the EVS group. Eradication was obtained in 44 (88%) with EVL and 41 (82%) with EVS with a mean of 3.41 and 5.29 treatments (p<0.001), respectively. Rebleeding occurred during eradication in 6 patients (12%) in the EVL group and 21 (42%) in the EVS group (p=0.001); after eradication, 7 patients (14%) rebled in the EVL group and 4 (8%) in the EVS group (not significant). Non-variceal bleeding was observed in 5 patients (2 EVL and 3 EVS) during follow-up. Two patients in the EVL group died after variceal rebleeding; 3 died of gastric bleeding; and, 15 from non-hemorrhagic events (8 EVL and 7 EVS). In the EVL group 14 patients had recurrent varices and 7 rebled; in the EVS group 11 recurred, with rebleeding in 5. Major complications were fewer in the EVL group (1 stenosis, 4 chronic ulcers) compared to 18 patients in the EVS group (9 stenosis and 9 chronic ulcers) (p<0.005).

CONCLUSIONS

EVL might be preferable to EVS for faster reduction and obliteration of varices, with a lower rate of complications and rebleeding before eradication. No differences were observed in recurrence.

Leukocyte-endothelial interaction is augmented by high glucose concentrations and hyperglycemia in a NF-kB-dependent fashion

We addressed the role of hyperglycemia in leukocyte-endothelium interaction under flow conditions by exposing human umbilical vein endothelial cells for 24 h to normal (5 mM), high concentration of glucose (30 mM), advanced glycosylation end product-albumin (100 microg/ml), or hyperglycemic (174-316 mg/dl) sera from patients with diabetes and abnormal hemoglobin A1c (8.1+/-1.4%). At the end of incubation endothelial cells were perfused with total leukocyte suspension in a parallel plate flow chamber under laminar flow (1.5 dyn/cm2). Rolling and adherent cells were evaluated by digital image processing. Results showed that 30 mM glucose significantly (P < 0. 01) increased the number of adherent leukocytes to endothelial cells in respect to control (5 mM glucose; 151+/-19 versus 33+/-8 cells/mm2). A similar response was induced by endothelial stimulation with IL-1beta, here used as positive control (195+/-20 cells/mm2). The number of rolling cells on endothelial surface was not affected by high glucose level. Stable adhesion of leukocytes to glucose-treated as well as to IL-1beta-stimulated endothelial cells was preceded by short interaction of leukocytes with the endothelial surface. The distance travelled by leukocytes before arrest on 30 mM glucose, or on IL-1beta-treated endothelial cells, was significantly (P < 0.01) higher than that observed for leukocytes adhering on control endothelium (30 mM glucose: 76.7+/-3.5; IL1beta: 69.7+/-4 versus 5 mM glucose: 21.5+/-5 microm). Functional blocking of E-selectin, intercellular cell adhesion molecule-1, and vascular cell adhesion molecule-1 on endothelial cells with the corresponding mouse mAb significantly inhibited glucose-induced increase in leukocyte adhesion (67+/-16, 83+/-12, 62+/-8 versus 144+/-21 cells/ mm2). Confocal fluorescence microscopy studies showed that 30 mM glucose induced an increase in endothelial surface expression of E-selectin, intercellular cell adhesion molecule-1, and vascular cell adhesion molecule-1. Electrophoretic mobility shift assay of nuclear extracts of human umbilical vein endothelial cells (HUVEC) exposed for 1 h to 30 mM glucose revealed an intense NF-kB activation. Treatment of HUVEC exposed to high glucose with the NF-kB inhibitors pyrrolidinedithiocarbamate (100 microM) and tosyl-phe-chloromethylketone (25 microM) significantly reduced (P < 0.05) leukocyte adhesion in respect to HUVEC treated with glucose alone. A significant (P < 0.01) inhibitory effect on glucose-induced leukocyte adhesion was observed after blocking protein kinase C activity with staurosporine (5 nM). When HUVEC were treated with specific antisense oligodesoxynucleotides against PKCalpha and PKCepsilon isoforms before the addition of 30 mM glucose, a significant (P < 0.05) reduction in the adhesion was also seen. Advanced glycosylation end product-albumin significantly increased the number of adhering leukocytes in respect to native albumin used as control (110+/-16 versus 66+/-7, P < 0.01). Sera from diabetic patients significantly (P < 0.01) enhanced leukocyte adhesion as compared with controls, despite normal levels of IL-1beta and TNFalpha in these sera. These data indicate that high glucose concentration and hyperglycemia promote leukocyte adhesion to the endothelium through upregulation of cell surface expression of adhesive proteins, possibly depending on NF-kB activation.

Sensitization of the striatal dopaminergic system induced by chronic administration of a glutamate antagonist in the rat

The aim of the present study was to assess in the rat the pharmacological, biochemical and molecular (including in situ hybridization) consequences in the striatum of a prolonged (50 days) treatment with dizocilpine maleate (MK-801), an N-methyl-D-aspartate (NMDA) antagonist. We observed a sensitization-like effect characterized by a behavioural hyperresponsiveness to an acute injection of haloperidol (0.25 mg/kg), a dopaminergic antagonist. In rats chronically treated with MK-801, this hyperresponsiveness was associated with an increased D2 receptor (D2R) density in the striatum. At the transcriptional level, the D2R mRNA was also enhanced in the striatum. Quantitative in situ hybridization studies revealed that the number of neurons expressing the D2R mRNA was significantly enhanced in treated rats, whereas the mean amount of message per cell was unchanged. These changes could represent the neurobiological substrate of the observed sensitization. These results suggest that the D2R gene is under glutamate control via NMDA receptor in striatal neurons.

Cyclosporine enhances leukocyte adhesion to vascular endothelium under physiologic flow conditions

We investigated the effect of cyclosporine (CyA) on leukocyte adhesion to endothelium under flow conditions. Confluent human umbilical vein endothelial cells (HUVECs) were incubated for 24 hours with CyA (1, 5, and 10 micromol/L) and then exposed to a total human leukocyte suspension in a parallel plate flow chamber under laminar flow (1.5 dynes/cm2. Human umbilical vein endothelial cells stimulated with interleukin-1beta (20 U/mL) were used as a positive control. Adherent cells were measured by digital image analysis. Results showed that CyA dose-dependently increased the number of leukocytes adhering to HUVECs compared with control cells. Leukocyte adhesion markedly increased on HUVECs incubated with interleukin-lbeta, one of the most potent inducers of endothelial cell adhesiveness. Exposure of endothelial cells to CyA did not affect the number of rolling leukocytes, which was similar to control values. To examine the role of adhesion molecules in CyA-induced leukocyte adhesion, HUVECs were incubated with monoclonal antibodies against intercellular adhesion molecule-1 (ICAM-1), vascular adhesion molecule-1 (VCAM-1), and E-selectin before adhesion assay. Functional blocking of ICAM-1, VCAM-1, and E-selectin on endothelial cells significantly inhibited CyA (10 micromol/L)-induced leukocyte adhesion. Confocal fluorescence microscopy studies showed that CyA induced an increase in the endothelial surface expression of ICAM-1, VCAM-1, and E-selectin. Pretreatment of leukocytes with the platelet activating factor receptor antagonist L659,989 significantly reduced the number of leukocytes adhering to CyA-treated HUVECs. We suggest that CyA enhances leukocyte adhesion to endothelium by upregulating adhesive proteins on endothelial surface membrane. Blocking leukocyte receptor for platelet-activating factor partially prevents adhesion, suggesting a role for endothelial cell-associated platelet-activating factor in the interaction between leukocytes and CyA-treated endothelium.

Verotoxin-1 promotes leukocyte adhesion to cultured endothelial cells under physiologic flow conditions

Hemolytic uremic syndrome (HUS), which is the most common cause of acute renal failure in infants and small children, is caused by verotoxin (VT)-producing Escherichia coli infection. Endothelial injury determines microvascular thrombosis and evidence is available from recent studies that suggests that leukocyte activation participates in endothelial damage. We studied here the effect of VT-1 on leukocyte adhesion to vascular endothelium under physiologic flow conditions. Human umbilical vein endothelial cells (HUVECs) were incubated for 24 hours with VT-1 (0.1, 1, and 10 pmol/L) and then exposed to a total leukocyte suspension in a parallel plate flow chamber under laminar flow conditions (1.5 dynes/cm2). Adherent cells were counted by digital image processing. Results showed that VT-1 dose-dependently increased the number of adhering leukocytes to HUVECs as compared with unstimulated cells. The adhesive response elicited by VT-1 was comparable to that of interleukin-1 beta (IL-1 beta), one of the most potent inducers of endothelial cell adhesiveness. Exposure of HUVECs to VT-1 did not affect the number of rolling leukocytes, which was similar to that of control values. To examine the role of adhesion molecules in VT-1-induced leukocyte adhesion, HUVECs were incubated with mouse monoclonal antibodies against E-selectin, intercellular adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1 (VCAM-1) before adhesion assay. Functional blocking of E-selectin, ICAM-1, and VCAM-1 on endothelial cells significantly inhibited VT-1-induced increase in leukocyte adhesion. In some experiments, before VT-1 incubation, HUVECs were pretreated for 24 hours with tumor necrosis factor alpha (TNF alpha; 100 U/mL), which is known to increase VT receptor expression on HUVECs. The number of adhering leukocytes on HUVECs exposed to TNF alpha and VT-1 significantly increased as compared with HUVECs incubated with VT-1 and TNF alpha alone. These results suggest that VT-1 modulates leukocyte-endothelium interaction, thus increasing leukocyte adhesion and upregulating adhesive proteins on endothelial surface membrane.

kappa-Opioid receptor in humans: cDNA and genomic cloning, chromosomal assignment, functional expression, pharmacology, and expression pattern in the central nervous system

Using the mouse delta-opioid receptor cDNA as a probe, we have isolated genomic clones encoding the human mu- and kappa-opioid receptor genes. Their organization appears similar to that of the human delta receptor gene, with exon-intron boundaries located after putative transmembrane domains 1 and 4. The kappa gene was mapped at position q11-12 in human chromosome 8. A full-length cDNA encoding the human kappa-opioid receptor has been isolated. The cloned receptor expressed in COS cells presents a typical kappa 1 pharmacological profile and is negatively coupled to adenylate cyclase. The expression of kappa-opioid receptor mRNA in human brain, as estimated by reverse transcription-polymerase chain reaction, is consistent with the involvement of kappa-opioid receptors in pain perception, neuroendocrine physiology, affective behavior, and cognition. In situ hybridization studies performed on human fetal spinal cord demonstrate the presence of the transcript specifically in lamina II of the dorsal horn. Some divergences in structural, pharmacological, and anatomical properties are noted between the cloned human and rodent receptors.

Fluid shear stress modulates surface expression of adhesion molecules by endothelial cells

We investigated the effect of hemodynamic shear forces on the expression of adhesive molecules, E-selectin, and intercellular adhesion molecule-1 (ICAM-1) on human umbilical vein endothelial cells (HUVEC) exposed to laminar (8 dynes/cm2) or turbulent shear stress (8.6 dynes/cm2 average), or to a static condition. Laminar flow induced a significant time-dependent increase in the surface expression of ICAM-1, as documented by flow cytometry studies. Endothelial cell surface expression of ICAM-1 in supernatants of HUVEC exposed to laminar flow was not modified, excluding the possibility that HUVEC exposed to laminar flow synthetize factors that upregulate ICAM-1. The effect of laminar flow was specific for ICAM-1, while E-selectin expression was not modulated by the flow condition. Turbulent flow did not affect surface expression of either E-selectin or ICAM-1. To evaluate the functional significance of the laminar-flow-induced increase in ICAM-1 expression, we studied the dynamic interaction of total leukocyte suspension with HUVEC exposed to laminar flow (8 dynes/cm2 for 6 hours) in a parallel-plate flow chamber or to static condition. Leukocyte adhesion to HUVEC pre-exposed to flow was significantly enhanced, compared with HUVEC maintained in static condition (233 +/- 67 v 43 +/- 16 leukocytes/mm2, respectively), and comparable with that of interleukin-1 beta treated HUVEC. Mouse monoclonal antibody anti-ICAM-1 completely blocked flow-induced upregulation of leukocyte adhesion. Interleukin-1 beta, which upregulated E-selectin expression, caused leukocyte rolling on HUVEC that was significantly lower on flow-conditioned HUVEC and almost absent on untreated static endothelial cells. Thus, laminar flow directly and selectively upregulates ICAM-1 expression on the surface of endothelial cells and promotes leukocyte adhesion. These data are relevant to the current understanding of basic mechanisms that govern local inflammatory reactions and tissue injury.

Chronic treatment with dizocilpine maleate increases the number of striatal neurons expressing the D2 receptor gene

N-methyl-D-aspartate antagonists have been proposed as potential therapeutic agents in different neurological diseases, including Parkinson's disease. The effects of gene expression of a chronic treatment with the non-competitive N-methyl-D-aspartate antagonist, dizocilpine maleate (0.8 mg/kg day, per os for 50 days) were analysed in rat striata. Using quantitative in situ hybridization, we measured the messenger RNA expression of the genes encoding D1, D2 dopamine receptors, N-methyl-D-aspartate receptor 1 subunit of N-methyl-D-aspartate receptor, preproenkephalin A and substance P. Chronic treatment with dizocilpine maleate induced a moderate but significant increase in messenger RNA of the N-methyl-D-aspartate receptor 1 subunit in the striatum and the adjacent cortex, suggesting an action of dizocilpine maleate in these two regions. This treatment did not induce any change in D1 receptor, preproenkephalin A or substance P messenger RNA content in the striatum, whereas D2 receptor messenger RNA was increased in the striatum of treated rats. Microscopic analysis revealed that it was the number of medium-sized neurons expressing D2 receptor messenger RNA that was significantly enhanced, while the mean amount of message per cell remained unchanged. These results demonstrate that glutamate via N-methyl-D-aspartate receptors, regulates the D2 receptor gene in striatal neurons. A chronic treatment with dizocilpine maleate increases the number of striatal neurons expressing the D2 receptor gene, suggesting a recruiting phenomenon.

The human delta-opioid receptor: genomic organization, cDNA cloning, functional expression, and distribution in human brain

We have used the mouse delta-opioid receptor (mDOR) cDNA to isolate the mDOR gene and its human homologue. In both species the coding region is interrupted by two introns with conserved exon-intron boundaries located after transmembrane domains 1 and 4. Using the polymerase chain reaction and primers based on the sequence of the cloned human delta-opioid receptor (hDOR) gene, we have obtained a full length cDNA encoding the hDOR from SH-SY5Y neuroblastoma cells. The cDNA sequence is 100% identical to the cloned human genomic sequence and 94% identical to the mouse sequence at the protein level. When expressed in COS cells, hDOR displays nanomolar affinities for delta-selective ligands, whereas the affinities for mu- and kappa-selective ligands are in the micromolar range. The delta agonists [D-Ala2, D-Leu5]enkephalin, cyclic [D-penicillamine2,D-penicillamine5]enkephalin, and BW373U86 efficiently decrease forskolin-induced cAMP levels in hDOR-expressing COS cells, indicating functional coupling of the receptor. The distribution of hDOR mRNA in human brain was investigated using delta-selective reverse transcription-polymerase chain reaction amplification, followed by Southern hybridization with a delta-specific probe. The transcript is found in cortical areas, including olfactory bulb, hippocampus, and amygdala, as well as in basal ganglia and hypothalamus. No expression is detected in internal globus pallidus, thalamus, any investigated brainstem structure, or pituitary gland. Taken together, our results indicate similar structural, pharmacological, functional, and anatomical properties for the hDOR and the mDOR and therefore support the use of rodent models for the study of these receptors in opioid function.

[Anatomic-functional relationships between the motor systems and the sleep-wakefulness systems]

The present paper deals with relationships between neural systems which control motor behaviour (pyramidal and extrapyramidal) and sleep-wakefulness states (in particular the reticular formation). We examined successively their anatomical and neurochemical substrates, electrophysiological and functional motor alterations depending on ascending and descending influences from brain stem during the sleep-wakefulness cycle. These data suggest that sleep-wake states result from the modulation of excitability in neuronal pools and that each state results from the co-ordinated working of several functionally different neuronal pools. Thus, each state could be understood as a sum of behavioural events depending on a neural network. We hypothesized that abnormal motor events occurring specifically during a sleep state could result from motor structures abnormally recruited in neural networks specifically involved in this sleep state.

[Parietal recurrence after resection of colorectal carcinoma]

The incidence of local recurrence of colo-rectal carcinoma is about 15-50%. The parietal recurrence is localized next parietal incision and its incidence is rare (0.2-2%). The treatment of this lesion is based on palliative radiotherapy and chemotherapy; the surgical treatment is based on parietal resection. The Authors describe a case of parietal recurrence after colo-rectal adenocarcinoma and conclude that the prognosis of this lesions is infaust.

[Hypocobaltemia in chronic obstructive arteriopathy. Physiopathologic and therapeutic importance]

The role of some so-called primary and secondary (or oligo-elements) elements in the physiopathology of the cardiocirculatory system has been well known from a number of years and they have been regularly included in the treatment protocols. Some, including K, Ca, Mg and Zn, are extremely well known and widely used in clinical practice. Recently, however, a growing number of studies have focused on the biological importance of other oligo-elements in the pathogenetic mechanisms of atherogenesis and its clinical manifestations. This study aimed to verify the exact role of free cobalt in the physiopathology of the chronic obstructive arterial diseases (COAD). A total of 80 patients affected by 2nd stage COAD were examined and the levels of some oligo-elements, including Co, were assayed. Constantly low levels were found (85% of cases) in relation to other oligo-elements studied (Cu, Zn, Mg, Ca). This findings is particularly interesting since it confirms the biochemical hypothesis of atherosclerosis according to which parietal damage plays a central role in the pathogenetic mechanism. Some enzymatic deficiencies, which lead to changes in membrane stability at the level of the endothelial cells, are closely related to the presence of tissutal and humoral peroxidation products. These peroxides (lipid peroxides), which are formed following the interaction of fatty acids with oxygen free radicals, have been identified by a number of studies as being responsible for endothelial damage. Several authors have shown that lipid peroxidation is involved in the atherogenic process through several mechanisms entailing monocytic activity and reduced prostacyclin (PG2) synthesis.(ABSTRACT TRUNCATED AT 250 WORDS)

Chronic administration of NMDA antagonists induces D2 receptor synthesis in rat striatum

Dopamine D2 receptor gene expression was examined in rat striatum after chronic treatment with N-methyl-D-aspartate (NMDA) receptor antagonists (ketamine at 15 mg/kg/day or MK-801 at 0.1, 0.2 and 0.4 mg/kg/day per os, for 50 days). The long-isoform mRNA, as well as the total D2 mRNA expression were induced. No change was noticed in striatal dopamine release or turnover. D2 binding studies carried out in MK-801 chronically treated (0.3 mg/kg/day per os, for 50 days) and control rats revealed an increased receptor density in treated animals without a significant change in receptor affinity. These results suggest that the synthesis of both striatal D2 receptor isoforms is postsynaptically regulated at the transcriptional level, by events triggered by glutamate through the NMDA-type receptor.

Behavioural, pharmacological and biochemical effects of acute and chronic administration of ketamine in the rat

The effects of N-methyl-D-aspartate (NMDA) antagonist ketamine given acutely or chronically were investigated on dopamine-related motor functions. Acute administration (15, 22.5, 30 mg/kg, i.p.) reversed the catalepsy induced by a dopamine (DA) antagonist (haloperidol, 0.25 mg/kg, i.p.) in the rat. When given orally and chronically (15 mg/kg per day) during at least 60 days, no alteration of spontaneous motor behaviour was observed, but the responsiveness to a DA agonist (apomorphine, 0.125 or 0.25 mg/kg s.c.) and to haloperidol was enhanced, suggesting an hypersensitivity of the DA receptors following the chronic blockade of NMDA receptors. However, following prolonged administration of ketamine there were no alteration of DA levels and turnover. Taken together these results suggest that the mechanisms involved in this DA receptor hypersensitivity should be postsynaptic.

Lesions of noradrenergic neurons in rats with spontaneous generalized non-convulsive epilepsy

The role of noradrenergic neurons in the control of a spontaneous generalized non-convulsive epilepsy (GNCE) was investigated. In rats with genetic spontaneous absence seizures, we produced lesions using 2 neurotoxins: 6-hydroxydopamine (6-OHDA) and N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine (DSP4). Lesions of noradrenergic neurons were made either in pups by neonatal 6-OHDA intraperitoneal (i.p.) injection (2 x 100 mg/kg) or in adult rats by i.p. administration of DSP4 (60 mg/kg) or bilateral microinjection of 6-OHDA in the locus coeruleus (LC) (4 micrograms/microliters, 2 microliters/side). Effectiveness of the lesions was controlled by measuring dopamine (DA) and noradrenaline (NA) contents in the brains. Neonatal 6-OHDA administration did not lead to any difference in seizures in adult animals, compared with control rats. DSP4 injections and LC lesions with local injections of 6-OHDA produced a transient increase of the seizures. Within one to two weeks, the seizure duration went back to prelesion levels. No seizure occurred when the same lesions were performed in non epileptic rats. These results suggest that NA is not involved in the genesis of this generalized non-convulsive epilepsy; they confirm that NA participates in the control of seizures in this model, but the rapid development of compensatory mechanisms shows that this control is not critical.

Suppression of spontaneous generalized non-convulsive seizures in the rat by microinjection of GABA antagonists into the superior colliculus

Intranigral injections of GABA agonists suppress spontaneous and chemically induced generalized non-convulsive seizures in the rat. In order to examine whether the GABAergic nigrotectal pathway could be involved in this suppression, bilateral injections of GABA antagonists were performed in the superior colliculus of rats with spontaneous generalized non-convulsive seizures. Bilateral microinjections into this structure of the GABA antagonists picrotoxin (20 and 40 ng/side) and bicuculline methiodide (5 ng/side) suppressed spike-and-wave discharges for 40 min and 20 min post injection, respectively. Unilateral injections of picrotoxin (40 ng) into the superior colliculus as well as bilateral injections of a GABA agonist (muscimol; 80 ng) did not induce significant modifications. These results show that blockade of the GABAergic transmission at the level of the superior colliculus results in a suppression of generalized non-convulsive seizures. These data support the hypothesis that the suppressive effect of intranigral injections of GABA agonists over generalized non-convulsive seizures involves, at least in part, the nigrotectal GABAergic pathway.

Interhemispheric desynchronization of spontaneous spike-wave discharges by corpus callosum transection in rats with petit mal-like epilepsy

Wistar rats of a strain inbred for spontaneous generalized non-convulsive seizures present EEG spike-wave discharges (SWDs), 7-10 c/sec, occurring about once/min and lasting about 15 sec. They are bilateral and synchronous and can be recorded over the entire neocortex and in the lateral thalamic nuclei. After corpus callosum section, only a few bilateral SWDs persisted. Asymmetrical SWDs were most often recorded: bilateral SWDs starting asynchronously, or unilateral SWDs, which were also seen to alternate abruptly between hemispheres. The thalamic SWDs were always synchronized with the ipsilateral cortical pattern. These findings suggest that while the corpus callosum has a major role in bilateral synchronization of SWD in this model of epilepsy, occasional synchronization may still occur through other pathways after callosal transection.

[Operations for limb salvage in vascular surgery]

Direct revascularization which involve the femoro-popliteo-tibial district is called "limbs salvage" surgery. Such operations are performed in the arteriopathic patient in order to avoid ulcers and distal necrosis, whose natural evolution, without an adequate treatment, leads to amputation. One of the distal by-pass techniques is obtained by using in situ saphenous vein. The Authors report their experience with 281 patients who underwent direct revascularization surgery (by-pass), discussing technique and results.

Relationship between spike-wave discharges and vigilance levels in rats with spontaneous petit mal-like epilepsy

The relationship between states of vigilance and spike and wave discharges (SWD) was examined during 12 hours in 4 Wistar rats from a strain bred for spontaneous generalized non-convulsant seizures. On the basis of cortical and hippocampal EEG and EMG activity, wakefulness (W), slow wave sleep (SWS) and paradoxical sleep (REM) were distinguished. Of the SWD 86% occurred during quiet W, 14% during the first minutes of SWS. No SWD occurred during active wakefulness and they were exceptional during REM. These results show that the states of quiet W and transitional states favour the SWD in rats with petit mal-like epilepsy, as in human petit mal.

Audiogenic seizures in Wistar rats before and after repeated auditory stimuli: clinical, pharmacological, and electroencephalographic studies

A strain of Wistar rats was inbred for susceptibility to audiogenic seizures characterized by one or two wild running fits followed by tonic dorsiflexion with open mouth and then a catatonic state. During the tonic phase, the cortical EEG was flat for 1 to 2 sec, then changed to a slow, regular low-amplitude discharge, 9 to 12 c/s, for 25 to 60 sec. In these rats exposed to 40 daily 90-sec auditory stimuli, behavior and EEG changed. The wild running became disorganized by myoclonic jerks of the limbs and body. In some animals, the tonic extension disappeared and a myoclonic seizure developed progressively, with facial and forelimb clonus, and rearing and falling. In others, the tonic phase was followed by a generalized clonic phase. The EEG during the myoclonic and tonic-clonic seizures showed high-amplitude rhythmic spikes, polyspikes and spike-waves, 1 to 10 c/s, for 40 to 120 sec, often outlasting the sound stimulus. The effects of ethosuximide, carbamazepine and phenytoin were the same on primary and modified audiogenic seizures. The progressive behavioral and EEG modifications of audiogenic seizures following repeated auditory stimuli suggest that kindling had developed, the seizures being propagated from the brain stem to forebrain structures.

Effects of gamma-hydroxybutyrate and gamma-butyrolactone derivates on spontaneous generalized non-convulsive seizures in the rat

The effects of derivatives of gamma-hydroxybutyrate (GHB) and gamma-butyrolactone were examined in Wistar rats from a strain in which spontaneous spike-and-wave discharges can be recorded electroencephalographically. For each compound, the effects were compared to those obtained in rats from a strain without spontaneous seizures. Administration of GHB (62.5-375 mg/kg, i.p.) increased, in a dose-dependent manner, the duration of spontaneous spike-and-wave discharges. In non-epileptic rats, this compound (250 and 375 mg/kg) induced bursts of spikes of a lower frequency and smaller amplitude than spontaneous spike-and-wave discharges. Similar results were obtained in both strains, respectively, after injection of gamma-butyrolactone (85-170 mg/kg, i.p.). This latter compound, however, showed greater potency in its epileptogenic effects than GHB. Administration of trans gamma-hydroxycrotonic acid (up to 1000 mg/kg, i.p.), a semi-rigid analogue of GHB was without any effect in both strains of rats. Injection of gamma-crotonolactone (42.5-170 mg/kg, i.p.), suppressed the spike-and-wave discharges in epileptic rats and had no effect in non-epileptic animals. These results confirm the similarities between seizures induced by GHB and spontaneous spike-and-wave discharges in the rat. The neural mechanism of the epileptogenic effect of GHB is discussed.