ABHD6 Inhibition Rescues a Sex-Dependent Deficit in Motor Coordination in The HdhQ200/200 Mouse Model of Huntington's Disease

Huntington's Disease is associated with motor behavior deficits that are lessened by few therapeutic options. This preliminary study tested if pharmacological inhibition of α/β-hydrolase domain containing 6 (ABHD6), a multifunctional enzyme expressed in the striatum, rescues behavioral deficits in HdhQ200/200 mice. Previous work has shown that this model exhibits a reduction in spontaneous locomotion and motor coordination at 8 and 10 months of age, with a more severe phenotype in female mice. Semi-quantitative immunohistochemistry analysis indicated no change in striatal ABHD6 expression at 8 months of age, but a 40% reduction by 10 months in female HdhQ200/200 mice compared to female wild-type (WT) littermates. At 8 months of age, acute ABHD6 inhibition rescued motor coordination deficits in female HdhQ200/200 mice without affecting WT performance. ABHD6 inhibition did not impact spontaneous locomotion, grip strength, or overall weight in either group, showing that effects were specific to motor coordination. At 10 months of age, semi-chronic ABHD6 inhibition by osmotic pump delivery also rescued motor coordination deficits in female HdhQ200/200 mice without affecting female WT littermates. Our preliminary study suggests that ABHD6 inhibition improves motor performance in female HdhQ200/200 mice.

The Influence of Diabetes Mellitus on the Outcome of Superficial Femoral Artery Recanalization is Debatable

Notwithstanding technological improvements in endovascular devices treatment of steno-obstructive lesions of the superficial femoral artery (SFA) remains a challenge for today's vascular surgeon. Current opinion dictates that the diabetic population may have worse outcome after revascularization of the lower extremities. Herein we examine the effects of endovascular treatment on steno-obstructive lesions of the SFA in diabetic and non-diabetic patients.

METHODS

A retrospective analysis was carried out on 110 patients who had undergone endovascular treatment of the SFA from 2010 to 2017 comparing outcomes in diabetic (DM) vs non-diabetic patients (nDM).

RESULTS

56 (50.9%) of the patients were diabetic and 54 were non-diabetic (49.1%). 52.7% (62.7% DM vs 35.2% nDM, p = 0.0003) were patients with critical limb ischemia. SFA occlusion was present in 65.5% (60.7% DM vs 70.4% nDM, p = 0.29) of all patients. All had undergone PTA of the SFA and 40.9% had received adjunctive stenting (44.6% DM vs 37.0% nDM, p = 0.41). A multilevel treatment was executed in 39.1% (51.8% DM vs 25.9% nDM) of the cases whereas an infra-popliteal procedure was associated in 27.3% (37.5% DM vs 16.7% nDM). In both groups the presence of diabetes was significantly associated (p = 0.005 e p = 0.014, respectively). Reintervention rate was 22.7%; 13 in the diabetic group (23.2%) and 12 in the non-diabetic group (22.2%). Of those who had had reintervention (p = 0.77); 9 patients (8.2%) had undergone an open surgical operation, 6 of whom had diabetes (p = 0.32). 5 patients (4.5%) had had major amputation, 4 of whom were diabetic (p = 0.20). Curves assessing freedom from target lesion restenosis were substantially overlapping between the two groups.

CONCLUSION

No statistical associations between diabetes and reintervention or amputation rates were found. Indication to treat the SFA were not influenced by the presence of diabetes but further investigation is required to verify our hypothesis.

CB2 receptors regulate natural killer cells that limit allergic airway inflammation in a murine model of asthma

BACKGROUND

Allergic asthma is a chronic airway inflammatory disease involving the complementary actions of innate and adaptive immune responses. Endogenously generated cannabinoids acting via CB2 receptors play important roles in both homeostatic and inflammatory processes. However, the contribution of CB2-acting eicosanoids to the innate events preceding sensitization to the common house dust mite (HDM) allergen remains to be elucidated. We investigated the role of CB2 activation during allergen-induced pulmonary inflammation and natural killer (NK) cell effector function.

METHODS

Lung mucosal responses in CB2-deficient (CB2^-/- ) mice were examined and compared with wild-type (WT) littermates following intranasal exposure to HDM allergen.

RESULTS

Mice lacking CB2 receptors exhibited elevated numbers of pulmonary NK cells yet were resistant to the induction of allergic inflammation exemplified by diminished airway eosinophilia, type 2 cytokine production and mucus secretion after allergen inhalation. This phenomenon was corroborated when WT mice were treated with a CB2-specific antagonist that caused a pronounced inhibition of HDM-induced airway inflammation and goblet cell hyperplasia. Unexpectedly, the preponderance of NK cells in the lungs of CB2^-/- mice correlated with reduced numbers of group 2 innate lymphoid cells (ILC2s). Depletion of NK cells restored the allergen responsiveness in the lungs and was associated with elevated ILC2 numbers.

CONCLUSIONS

Collectively, these results reveal that CB2 activation is crucial in regulating pulmonary NK cell function, and suggest that NK cells serve to limit ILC2 activation and subsequent allergic airway inflammation. CB2 inhibition may present an important target to modulate NK cell response during pulmonary inflammation.

Transmission of HIV Drug Resistance and the Predicted Effect on Current First-line Regimens in Europe

Transmitted human immunodeficiency virus drug resistance in Europe is stable at around 8%. The impact of baseline mutation patterns on susceptibility to antiretroviral drugs should be addressed using clinical guidelines. The impact on baseline susceptibility is largest for nonnucleoside reverse transcriptase inhibitors.

Background. Numerous studies have shown that baseline drug resistance patterns may influence the outcome of antiretroviral therapy. Therefore, guidelines recommend drug resistance testing to guide the choice of initial regimen. In addition to optimizing individual patient management, these baseline resistance data enable transmitted drug resistance (TDR) to be surveyed for public health purposes. The SPREAD program systematically collects data to gain insight into TDR occurring in Europe since 2001.

Methods. Demographic, clinical, and virological data from 4140 antiretroviral-naive human immunodeficiency virus (HIV)–infected individuals from 26 countries who were newly diagnosed between 2008 and 2010 were analyzed. Evidence of TDR was defined using the WHO list for surveillance of drug resistance mutations. Prevalence of TDR was assessed over time by comparing the results to SPREAD data from 2002 to 2007. Baseline susceptibility to antiretroviral drugs was predicted using the Stanford HIVdb program version 7.0.

Results. The overall prevalence of TDR did not change significantly over time and was 8.3% (95% confidence interval, 7.2%–9.5%) in 2008–2010. The most frequent indicators of TDR were nucleoside reverse transcriptase inhibitor (NRTI) mutations (4.5%), followed by nonnucleoside reverse transcriptase inhibitor (NNRTI) mutations (2.9%) and protease inhibitor mutations (2.0%). Baseline mutations were most predictive of reduced susceptibility to initial NNRTI-based regimens: 4.5% and 6.5% of patient isolates were predicted to have resistance to regimens containing efavirenz or rilpivirine, respectively, independent of current NRTI backbones.

Conclusions. Although TDR was highest for NRTIs, the impact of baseline drug resistance patterns on susceptibility was largest for NNRTIs. The prevalence of TDR assessed by epidemiological surveys does not clearly indicate to what degree susceptibility to different drug classes is affected.

G protein-coupled receptors as oncogenic signals in glioma: emerging therapeutic avenues

Gliomas are the most common malignant intracranial tumors. Newly developed targeted therapies for these cancers aim to inhibit oncogenic signals, many of which emanate from receptor tyrosine kinases, including the epidermal growth factor receptor (EGFR) and the vascular endothelial growth factor receptor (VEGFR). Unfortunately, the first-generation treatments targeting these oncogenic signals provide little survival benefit in both mouse xenograft models and human patients. The search for new treatment options has uncovered several G protein-coupled receptor (GPCR) candidates and generated a growing interest in this class of proteins as alternative therapeutic targets for the treatment of various cancers, including glioblastoma multiforme (GBM). GPCRs constitute a large family of membrane receptors that influence oncogenic pathways through canonical and non-canonical signaling. Accordingly, evidence indicates that GPCRs display a unique ability to crosstalk with receptor tyrosine kinases, making them important molecular components controlling tumorigenesis. This review summarizes the current research on GPCR functionality in gliomas and explores the potential of modulating these receptors to treat this devastating disease.

Endotension-related aortic sac rupture treated by endograft relining

Endovascular aortic aneurysm repair is an effective alternative to open surgical repair in high risk patient. Endotension is an unpredictable late and rare complication of EVAR. Clinical significance and choice of technique for treatment are controversial. At present, there are no cases of endotension-related aneurysmal sac rupture reported in literature, altough it is frequently associated with late surgical conversion. In this case report is described a case of a patient treated with a first generation Gore Excluder(TM) endograft for abdominal aortic aneurysm, with late aneurysmal sac enlargement without evidence of endoleak and subsequent contained rupture without anemia and shock. We have successfully treated the patient by endovascular procedure, through bilateral percutaneous femoral approach, with relining technique. Three years CT scan follow-up showed the endograft patency and size sac reduction.

Transcranial Doppler and diffusion-weighted magnetic resonance evaluation of cerebral embolization occurring during transfemoral carotid stenting with proximal flow blockage

AIM: Transfemoral carotid artery stenting (CAS) with endovascular proximal flow blockage is deemed able to reduce the cerebral embolization observed during filter-protected CAS. We evaluated clinical outcome and intraoperative embolization rates, measured by diffusion-weighted magnetic resonance imaging (DW-MRI) and transcranial Doppler monitoring, in a series of patients undergoing CAS with proximal flow blockage. METHODS: A series of 35 consecutive patients with symptomatic or asymptomatic internal carotid artery stenosis ≥70% were included to undergo CAS with proximal flow blockage, obtained with the Mo.Ma system. All patients underwent preoperative and postoperative DW-MRI in order to detect new ischemic lesions. Of the 35 patients, 31 (89%) underwent intraoperative transcranial Doppler monitoring to record the microembolic signals (MES) produced during each procedure. RESULTS: The MoMa system was successfully used in 34 patients (technical success: 97%). Intolerance to balloon occlusion was observed in 4 patients (12%), but never compromised the completion of the procedure. No deaths or neurological events occurred in the postoperative period. DW-MRI disclosed 74 new ischemic lesions in 8 patients (8/34, 23.5%). All lesions except one were ipsilateral to the treated carotid artery. MES were detected in all procedures, with a mean number of 33.2±23.2 (range 3-103). In 20 procedures (20/31, 65%), MES were detected also during flow blockage (mean: 9.1±7; range 2-28). CONCLUSION: While achieving good technical and clinical results, CAS with proximal flow blockage is still accompanied by a non-negligible cerebral embolization. The detection of MES during ICA flow blockage suggests the need for a better selection of patients.

Aortic arch catheterization during transfemoral carotid artery stenting: an underestimated source of cerebral emboli

Cerebral embolization is still a major concern in patients undergoing transfemoral carotid artery stenting. Intraoperative transcranial Doppler (TCD) monitoring and diffusion-weighted magnetic resonance imaging (DW-MRI), two techniques currently used to study this phenomenon, have provided data suggesting the importance of aortic arch catheterization in determining the overall embolic load observed during this procedure. In order to reduce this cerebral embolization, some Authors have proposed the performance of carotid artery stenting through a cervical access, either surgical or percutaneous. We review in this article the available TCD and DW-MRI data supporting transcervical CAS, along with its clinical results.

Hybrid lattice Boltzmann model for binary fluid mixtures

A hybrid lattice Boltzmann method (LBM) for binary mixtures based on the free-energy approach is proposed. Nonideal terms of the pressure tensor are included as a body force in the LBM kinetic equations, used to simulate the continuity and Navier-Stokes equations. The convection-diffusion equation is studied by finite-difference methods. Differential operators are discretized in order to reduce the magnitude of spurious velocities. The algorithm has been shown to be stable and reproducing the correct equilibrium behavior in simple test configurations and to be Galilean invariant. Spurious velocities can be reduced by approximately an order of magnitude with respect to standard discretization procedure.

Safety and effectiveness of combining carotid artery stenting with cardiac surgery: preliminary results of a single-center experience

AIM

Optimal strategy (staged or combined) for the treatment of patients with concurrent severe carotid and cardiac disease is still controversial. Moreover, carotid artery stenting (CAS), has become a valid alternative to carotid endarterectomy (CEA) and has been proposed for the treatment of cardiac patients. The authors report the preliminary results of a new therapeutic strategy consisting in combined CAS and cardiac surgery.

METHODS

An initial series of 22 patients underwent combined CAS and cardiac surgery in the same operating room and under general anesthesia. All filter-protected CAS procedures were performed under only heparin and aspirin. A cervical approach (3-cm cervicotomy) was used in patients with documented vessel tortuosity or severe aorto-iliac occlusive arteriopathy. In all the other cases a femoral access was used. A double antiplatelet regimen was initiated in the early postoperative period, once major bleedings were excluded.

RESULTS

Among the 22 patients who underwent this combined procedure, no deaths, no myocardial infarctions and one controlateral stroke (overall complication rate: 4.5%) were observed. This stroke was observed after transcervical CAS, coronary artery bypass and mitral valve replacement. No major postoperative bleedings nor stent thrombosis were observed.

CONCLUSIONS

Combined carotid stenting and cardiac surgery, performed in the same operating room under only heparin and aspirin, seems a safe and effective strategy for the treatment of patients with concomitant carotid and cardiac disease.

Late evaluation of silent cerebral ischemia detected by diffusion-weighted MR imaging after filter-protected carotid artery stenting

BACKGROUND AND PURPOSE

Postoperative diffusion-weighted MR imaging (DWI) often discloses new lesions after carotid artery stent placement (CAS), most of them asymptomatic. Our aim was to investigate the fate of these silent ischemic lesions.

MATERIALS AND METHODS

We prospectively studied 110 patients undergoing protected transfemoral CAS, 98 of whom underwent DWI before and after the intervention. Patients in whom DWI disclosed silent postoperative lesions also had delayed MR imaging. Preoperative, postoperative, and delayed scans were compared.

RESULTS

Of the 92 patients without postoperative symptoms, DWI disclosed 33 new silent ischemic lesions in 14 patients (15.2%), 13 of whom (30 lesions) underwent delayed MR imaging after a mean follow-up of 6.2 months. In 8 of these 13 patients (61%), MR imaging disclosed 12 persistent lesions (12/30, 40%). The reversibility rate depended significantly on the location (cortical versus subcortical) and size (0-5 versus 5-10 mm) of the lesions (P < .05 by chi(2) test).

CONCLUSIONS

Because many silent ischemic lesions seen on postoperative DWI after CAS reverse within months, the extent of permanent CAS-related cerebral damage may be overestimated.

Cerebral embolization in patients undergoing protected carotid-artery stenting and carotid surgery

AIM

Intraoperative cerebral embolization is a greater concern in patients undergoing carotid-artery stenting (CAS) than in those undergoing the reference standard treatment carotid endarterectomy (CEA). We evaluated cerebral embolism with diffusion-weighted magnetic resonance imaging (DW-MRI) and transcranial Doppler monitoring during CAS and CEA.

METHODS

A series of 75 patients with carotid stenosis, 40 undergoing CEA and 35 transfemoral protected CAS, underwent preoperative and postoperative cerebral DW-MRI. Of the 75 patients, 64 (85%) underwent intraoperative transcranial Doppler monitoring to evaluate the mean number of microembolic signals (MES) recorded in each procedure.

RESULTS

None of the patients died. No patient in the CEA but two in the CAS group had strokes (5.7%, P=NS). The mean MES count on transcranial Doppler monitoring was higher in the CAS than in the CEA group (330.0 MES, range 2754 vs 13.2, range 0-49 MES; P<0.01). DW-MRI disclosed a significantly larger number of new ischemic lesions in the CAS than in the CEA group (40 lesions in 12/35 patients, 34.3% vs 4 lesions in 3/40 patients, 7.5%; P<0.01). In the CEA group, all patients with ischemic lesions were asymptomatic whereas in the CAS group 5 were symptomatic (14.3%) and 7 asymptomatic (20%). The cerebral distribution also differed in the two groups: no CEA but 20% of CAS lesions were contralateral.

CONCLUSION

CAS is associated with a significantly higher rate of cerebral embolization than CEA. Even though the clinical meaning of new postoperative ischemic lesions remains debatable, it seems prudent to reduce the embolic load by improving procedural techniques and cerebral protection devices.

[Diagnostic and operative fertiloscopy]

In the last decade, ''fertiloscopy'', a new mini-invasive diagnostic technique, is becoming more and more popular: it is a good alternative to the diagnostic laparoscopy, a standard procedure but surely not harmless, very often capable to discover pathologies in asymptomatic patients. Fertiloscopy allows the visualization of the posterior pelvis (posterior face of the uterus, ovaries, tubes and intestinal ansae with the rectum), with a technique of introducing an optical device in the pouch of Douglas, through the posterior vaginal fornix, under previous general or local anesthesia. When fertiloscopy is performed under local anesthesia, it can comfortably be carried out in out-patient departments and it is generally well tolerated by patients, who follow the whole procedure on the monitor. Moreover, it is possible to perform small interventions, such as adhesiolysis, ovarian drilling, coagulation of endometriosis spots and to perform chromosalpingoscopy and salpingoscopy, important investigations in the diagnostic iter of unexplained female infertility. With fertiloscopy, the patient, therefore, can avoid a real surgical intervention, such as diagnostic laparoscopy, and also uncomfortable examinations, such as hysterosalpingography.

[Voluminous ectopic polycystic ovaries in Mayer-Rokitansky-Küster-Hauser syndrome]

We report the case of a 20-year-old woman with primary amenorrhea, normally developed sexual characteristics, infantile external genitals and absence of vaginal orifice. Blood chemistry studies showed elevated serum levels of gonadotropin, estrogens, testosterone, 17OH-progesterone, prolactin and TSH and low concentrations of FT(3) and FT(4). Cytogenetic karyotyping and in situ fluorescence hybridization revealed a 46,XX karyotype and the presence of Barr chromatin body. Laparoscopy disclosed absence of a vagina, apparently normal, enlarged tubes, multifolicular ectopic gonads and symmetric bilateral uterine buds. Diagnostic work-up included skeletal radiography, renal ultrasonography, intravenous pyelography, pelvic echography, pelvic phlebography and magnetic resonance imaging studies to demonstrate possible associations between the genitourinary and skeletal anomalies. Based on the clinical and laboratory findings, a diagnosis of Mayer-Rokitansky-Küster-Hauser syndrome was established, associated with the presence of enlarged ectopic polycystic ovaries in the abdominal cavity.

Endovascular exclusion of iatrogenic femoral artery pseudoaneurysm with the Wallgraft-Endoprosthesis

Development of femoral artery pseudoaneurysm represents a continuing problem after percutaneous peripheral interventional procedures as well as coronary angioplasty. We report a case of symptomatic, expanding femoral artery pseudoaneurysm in a 60-year-old man who underwent percutaneous transluminal coronary angioplasty and stenting for acute myocardial infarction. A self-expanding Wallgraft Endoprosthesis (Boston Scientific, USA) was delivered under fluoroscopic guidance via contralateral percutaneous femoral approach to the site, resulting in immediate complete exclusion of the pseudoaneurysms. Follow-up color duplex scanning confirmed false aneurysm exclusion 1 year postprocedure. Endovascular treatment of iatrogenic pseudoaneurysm appears to be an attractive alternative to surgical repair in critically ill patients, with a high degree of technical success, low morbidity and short hospital stay.

Post-traumatic pseudoaneurysm of the common carotid artery. Importance of echo-Doppler evaluation of the intimal damage

Nonpenetrating traumas of the extracranial carotid artery are uncommon and frequently involve the carotid bifurcation. We report a case of asymptomatic post-traumatic pseudoaneurysm of the common carotid artery in a 32-year-old woman, detected by chance 12 years after a cervical injury. Of all the investigations, only echo-Doppler permitted the detection of an intimal tear at the level of the aneurysmatic dilatation. After aneurysmectomy, 8 mm PTFE graft replacement was carried out. We believe that routine use of echo-Doppler ultrasonography in all asymptomatic patients with a definite history of contusive cervical trauma should be recommended. In our opinion, the absolute surgical indication resulted from the local and neurological complications potentially stemming from the pseudoaneurysmatic dilatation.

Receptor-dependent formation of endogenous cannabinoids in cortical neurons

We investigated the transduction mechanisms mediating formation of the endogenous cannabinoid (endocannabinoid) lipids, anandamide (arachidonylethanolamide) and 2-arachidonylglycerol, in primary cultures of rat cortical neurons. Unstimulated neurons contained 0.3 +/- 0.1 pmol of anandamide and 16.5 +/- 3.3 pmol of 2-arachidonylglycerol per mg of protein, as determined by gas chromatography/mass spectrometry. Ca(2+) entry into the neurons via activated glutamate N-methyl-D-aspartate (NMDA) receptors increased 2-arachidonylglycerol levels approximately three times, but had no effect on anandamide levels. By contrast, anandamide formation was stimulated five times by simultaneous activation of NMDA and acetylcholine receptors. Alone, acetylcholine receptor activation had no effect on anandamide or 2-arachidonylglycerol levels. The formation of fatty acid ethanolamides that do not activate cannabinoid receptors, including palmitylethanolamide and oleylethanolamide, was stimulated by coactivation of NMDA and acetylcholine receptors. Pharmacological experiments suggest that the cholinergic contribution to anandamide formation was mediated by alpha7 nicotinic receptors (antagonized by methyllycaconitine), whereas the contribution to palmitylethanolamide and oleylethanolamide formation was mediated by muscarinic receptors (antagonized by atropine). These findings indicate that cortical neurons produce anandamide and 2-arachidonylglycerol in a receptor-dependent manner, and that brain neurons may generate different endocannabinoid lipids depending on their complement of neurotransmitter receptors.

[Simultaneous urokinase perfusion in renal artery and vein in a case of renal vein thrombosis]

We present he case of a young man with nephrotic syndrome, caused by membranous glomerulonephritis, who developed renal vein thrombosis with extension to the inferior vena cava is presented. Renal vein thrombosis was diagnosed by echo Doppler and confirmed by angio-CT scan. At the hospitalization the patient presented a severe left flank pain, edema of the lower limbs and painful left testicular tumefaction. The treatment consisted of: 1) systemic anticoagulation with sodic heparin, 2) placement of temporary vena cava filter through the right jugular vein, 3) direct thrombolysis into endocaval thrombus with early lysis of thrombus, and 4) renal thrombolysis with selective simultaneous renal artery and renal vein infusion of urokinase. Angiography performed after 24 hours of loco-regional thrombolysis showed complete lysis of renal thrombus; clinically there was a regression of left flank pain. We conclude that, face to renal vein thrombosis, thrombolytic treatment with simultaneous renal artery and renal vein perfusion is mandatory. Furthermore it is very important, in presence of caval extension of renal thrombus, to place a temporary vena cava filter before starting thrombolysis, considering the high risk of pulmonary embolism related to this pathology.

Evidence supporting the existence of an activity-dependent astrocyte-neuron lactate shuttle

Mounting evidence from in vitro experiments indicates that lactate is an efficient energy substrate for neurons and that it may significantly contribute to maintain synaptic transmission, particularly during periods of intense activity. Since lactate does not cross the blood-brain barrier easily, blood-borne lactate cannot be a significant source. In vitro studies by several laboratories indicate that astrocytes release large amounts of lactate. In 1994, we proposed a mechanism whereby lactate could be produced by astrocytes in an activity-dependent, glutamate-mediated manner. Over the last 2 years we have obtained further evidence supporting the notion that a transfer of lactate from astrocytes to neurons might indeed take place. In this article, we first review data showing the presence of mRNA encoding for two monocarboxylate transporters, MCT1 and MCT2, in the adult mouse brain. Second, by using monoclonal antibodies selectively directed against the two distinct lactate dehydrogenase isoforms, LDH1 and LDH5, a specific cellular distribution between neurons and astrocytes is revealed which suggests that a population of astrocytes is a lactate 'source' while neurons may be a lactate 'sink'. Third, we provide biochemical evidence that lactate is interchangeable with glucose to support oxidative metabolism in cortical neurons. This set of data is consistent with the existence of an activity-dependent astrocyte-neuron lactate shuttle for the supply of energy substrates to neurons.

Cannabinoid CB1 receptors and ligands in vertebrate retina: localization and function of an endogenous signaling system

CB1, a cannabinoid receptor enriched in neuronal tissue, was found in high concentration in retinas of rhesus monkey, mouse, rat, chick, goldfish, and tiger salamander by using a subtype-specific polyclonal antibody. Immunolabeling was detected in the two synaptic layers of the retina, the inner and outer plexiform layers, of all six species examined. In the outer plexiform layer, CB1 was located in and/or on cone pedicles and rod spherules. Labeling was detected in some amacrine cells of all species and in the ganglion cells and ganglion cell axons of all species except fish. In addition, sparse labeling was found in the inner and/or outer segments of the photoreceptors of monkey, mouse, rat, and chick. Using GC/MS to detect possible endogenous cannabinoids, we found 3 nmol of 2-arachidonylglycerol per g of tissue, but no anandamide was detectable. Cannabinoid receptor agonists induced a dramatic reduction in the amplitude of voltage-gated L-type calcium channel currents in identified retinal bipolar cells. The presence and distribution of the CB1 receptor, the large amounts of 2-arachidonylglycerol found, and the effects of cannabinoids on calcium channel activity in bipolar cells suggest a substantive role for an endogenous cannabinoid signaling system in retinal physiology, and perhaps vision in general.

Functional role of high-affinity anandamide transport, as revealed by selective inhibition

Anandamide, an endogenous ligand for central cannabinoid receptors, is released from neurons on depolarization and rapidly inactivated. Anandamide inactivation is not completely understood, but it may occur by transport into cells or by enzymatic hydrolysis. The compound N-(4-hydroxyphenyl)arachidonylamide (AM404) was shown to inhibit high-affinity anandamide accumulation in rat neurons and astrocytes in vitro, an indication that this accumulation resulted from carrier-mediated transport. Although AM404 did not activate cannabinoid receptors or inhibit anandamide hydrolysis, it enhanced receptor-mediated anandamide responses in vitro and in vivo. The data indicate that carrier-mediated transport may be essential for termination of the biological effects of anandamide, and may represent a potential drug target.

A second endogenous cannabinoid that modulates long-term potentiation

Cannabinoid receptors are molecular targets for marijuana and hashish, the widespread drugs of abuse. These receptors are expressed in areas of the central nervous system that contribute in important ways to the control of memory, cognition, movement and pain perception. Indeed, such functions can be strongly influenced by cannabinoid drugs, with consequences that include euphoria, analgesia, sedation and memory impairment. Although the pharmacology of cannabinoid drugs is now beginning to be understood, we still lack essential information on the endogenous signalling system(s) by which cannabinoid receptors are normally engaged. An endogenous ligand for cannabinoid receptors, anandamide, has been described. Here we report that sn-2 arachidonylglycerol (2-AG), a cannabinoid ligand isolated from intestinal tissue, is present in brain in amounts 170 times greater than anandamide. 2-AG is produced in hippocampal slices by stimulation of the Schaffer collaterals, an excitatory fibre tract that projects from CA3 to CA1 neurons. Formation of 2-AG is calcium dependent and is mediated by the enzymes phospholipase C and diacylglycerol lipase. 2-AG activates neuronal cannabinoid receptors as a full agonist, and prevents the induction of long-term potentiation at CA3-CA1 synapses. Our results indicate that 2-AG is a second endogenous cannabinoid ligand in the central nervous system.

Interleukin-1 enhances the ATP-evoked release of arachidonic acid from mouse astrocytes

During neuropathological states associated with inflammation, the levels of cytokines such as interleukin-1beta (IL-1beta) are increased. Several studies have suggested that the neuronal damage observed in pathogenesis implicating IL-1beta are caused by an alteration in the neurochemical interactions between neurons and astrocytes. We report here that treating striatal astrocytes in primary culture with IL-1beta for 22-24 hr enhances the ATP-evoked release of arachidonic acid (AA) with no effect on the ATP-induced accumulation of inositol phosphates. The molecular mechanism responsible for this effect involves the expression of P2Y2 receptors (a subtype of purinoceptor activated by ATP) and cytosolic phospholipase A2 (cPLA2, an enzyme that mediates AA release). Indeed, P2Y2 antisense oligonucleotides reduce the ATP-evoked release of AA only from IL-1beta-treated astrocytes. Further, both the amount of cPLA2 (as assessed by Western blotting) and the release of AA resulting from direct activation of cPLA2 increased fourfold in cells treated with IL-1beta. We also report evidence indicating that the coupling of newly expressed P2Y2 receptors to cPLA2 is dependent on PKC activity. These results suggest that during inflammatory conditions, IL-1beta reveals a functional P2Y2 signaling pathway in astrocytes that results in a dramatic increase in the levels of free AA. This pathway may thus contribute to the neuronal loss associated with cerebral ischemia or traumatic brain injury.

Mechanism involved in initiation and propagation of receptor-induced intercellular calcium signaling in cultured rat astrocytes

The mechanisms involved in the initiation and the propagation of intercellular calcium signaling (calcium waves) were studied in cultured rat astrocytes. The analysis of calcium waves, induced either by mechanical stimulation or by focal application of ionomycin, indicated that initiation was dependent on the presence of external calcium. In addition, pharmacological experiments indicate that intercellular propagation required PLC activation, integrity of IP3-sensitive internal calcium stores, and functional gap junctions. An extracellular action of ATP or glutamate and participation of voltage-dependent Ca2+ channels were tested by using enzymatic degradation, receptor antagonists, and channel blockers, respectively. Because neither the speed of propagation nor the extent of the calcium waves was affected by these treatments, these alternate mechanisms were excluded from playing a role in intercellular calcium signaling. Biochemical assays and focal applications of several agonists (methoxamine, carbachol, glutamate) of membrane receptors to neurotransmitters and peptides (endothelin 1) demonstrated that their ability to trigger regenerative calcium waves depended on phospholipase C activity and inositol phosphate production. Thus, in rat astrocytes, initiation and propagation of calcium waves involve a sequence of intra- and intercellular steps in which phospholipase C, inositol trisphosphate, internal calcium stores, and gap junction channels play a critical role. The identification of these different events allows us to determine several targets at which the level of long-range signaling in astrocytes may be controlled.

[Endovascular treatment of abdominal aorta aneurysms using the Stentor device. Preliminary experience]

PURPOSE

The aim of this report is to describe our experience with the Stentor device for endovascular treatment of the abdominal aortic infrarenal aneurysms also extending to the bifurcation and the common iliac arteries. Stentor is a thermal memory (Nitinol) self-expanding graft, covered by an external 0.1 mm Dacron material.

METHODS

Between December 1994 and July 1995 endoluminal repair of infrarenal aneurysmal disease was undertaken in 6 patients at high surgical risk. The lesions include 2 infrarenal abdominal aorto-aortic aneurysms, 2 infrarenal abdominal aortic aneurysms extended to the common iliac arteries and 2 false aortic aneurysms in patients with previous aorto-bifemoral graft. Straight grafts were implanted in 4 patients and bifurcated in 2. Repair was done in the operating room using general anesthesia. The endograft was placed through remote arteriotomies and advanced under fluoroscopic guidance to his predetermined site. Three-dimensionally reconstructed spiral CT scan and arteriography were performed before the procedure for a preoperative accurate measurement for endograft preprocedural adaptation in length and diameter.

RESULTS

All endografts were successfully deployed. Intraoperative arteriography at the end of the procedure revealed a distal "leak" into an aneurysmal common iliac artery, due to diameter mismatch, in a bifurcated device. There was no instance of embolism or graft migration. No patient required conversion to an open operation. There were no instances of embolism or graft migration. No patient required conversion to an open operation. There were no coagulative disorders. Minor complications were: groin haematoma (1), fever (1), intestinal paralysis (1), pelvic pain (1). Follow-up with spiral CT-scan and echo color-Doppler confirmed normal blood flow through the graft in 5 patients and persistence of distal leak in 1 patient.

CONCLUSIONS

These preliminary results demonstrate the accuracy of implantation and device's adaptability to the particular anatomy of the aneurysmal aorta and iliac arteries. Proximal fixation to the aortic wall, secure seal at the proximal and distal fixation point present the critical aspects of this new surgical technique. More detailed preoperative measurements of aneurysmal disease are required rather than for traditional surgery. Presently we prefer to treat the no operable patients with this endovascular technique in relation with shortness of the follow-up.

Vasoactive intestinal peptide (VIP) and pituitary adenylate cyclase-activating polypeptide (PACAP) potentiate the glutamate-evoked release of arachidonic acid from mouse cortical neurons. Evidence for a cAMP-independent mechanism

Glutamatergic neurotransmission is associated with release of arachidonic acid (AA) from membrane phospholipids of both neurons and astrocytes. Since free AA has been shown to enhance glutamate-mediated synaptic transmission, it can be postulated that glutamate release and AA formation constitute a positive feed-back mechanism for sustained excitatory neurotransmission. In the present study, we examined whether the glutamate-evoked release of AA could be modulated by peptides. Using mouse cortical neurons in primary cultures, we show that the release of AA evoked by glutamate is potentiated by vasoactive intestinal peptide and pituitary adenylate cyclase-activating polypeptide (PACAP). This effect is mediated through the activation of PACAP I receptors. However, several arguments show that this potentiating mechanism does not involve the cAMP/PKA pathway. 1) Increasing intracellular cAMP by either cholera toxin, forskolin, or 8-Br-cAMP treatments does not affect the glutamate-evoked release of AA; 2) potentiation of the glutamate response by PACAP is not prevented by the PKA inhibitor 8-Br-Rp-cAMPS. Also, an involvement of the phospholipase C protein kinase C pathways is unlikely since inhibitors of both phospholipase C (i.e. U-73122) and protein kinase C (i.e. Ro 31-8220) do not affect the potentiation of the glutamate response by PACAP. These observations indicate an effect mediated by PACAP I receptors, which does not involve the second messenger pathways classically associated with activation of this type of receptors. Furthermore, results indicate that this potentiating mechanism mediated by PACAP I receptor acts at a level downstream of the glutamate receptor-mediated calcium influx.

Reduced glucose metabolism enhances the glutamate-evoked release of arachidonic acid from striatal neurons

Glucose deprivation potentiates the glutamate receptor-evoked release of arachidonic acid from cultured mouse striatal neurons. In this study we investigated whether this potentiation would be modified by the end-products of glycolysis. These enhanced responses were completely reversed by the addition of increasing concentrations of either lactate or pyruvate. This reversal was not due to increased osmolarity as substituting sucrose for lactate or pyruvate did not mimic their effects. In contrast, in the presence of glucose, neither lactate nor pyruvate was effective. Furthermore, these monocarboxylic acids rescued neuronal respiration in the absence of glucose. Inhibiting glycolysis with iodoacetate in the presence of glucose reproduced the potentiated glutamate-evoked release of arachidonic acid observed following glucose deprivation and reduced neuronal respiration to the same extent as that observed in the absence of glucose. All of these effects were overcome by the addition of either lactate or pyruvate. The reversal of the potentiated glutamate-evoked release of arachidonic acid by lactate or pyruvate was inhibited by a specific inhibitor of monocarboxylic acid transport, alpha-cyano-4-hydroxycinnamic acid, suggesting that lactate and pyruvate act intracellularly. Therefore, we propose that the enhanced release of arachidonic acid evoked by glutamate during glucose deprivation results from reduced glycolysis and hence from a depletion of lactate or pyruvate.

Modulation of the glutamate-evoked release of arachidonic acid from mouse cortical neurons: involvement of a pH-sensitive membrane phospholipase A2

Excitatory synaptic transmission is associated with changes in both extracellular and intracellular pH. Using mouse cortical neurons in primary cultures, we studied the sensitivity of glutamate-evoked release of 3H-arachidonic acid (3H-AA) to changes in extracellular pH (pHo) and related intracellular pH (pHi). As pHo was shifted from 7.2 to 7.8, the glutamate-evoked release of 3H-AA was enhanced by approximately threefold. The effect of alkaline pHo on the glutamate response was rapid, becoming significant within 2 min. 3H-AA release, evoked by both NMDA and kainate, was also enhanced by pHo alkalinization. NMDA- and kainate-induced increase in free intracellular Ca2+ was unaffected by changing pHo from 7.2 to 7.8, indicating that the receptor-induced Ca2+ influx is not responsible for the pHo sensitivity of the glutamate-evoked release of 3H-AA. Alkalinization of pHi obtained by incubating neurons in the presence of HCO3- or NH4 enhanced the glutamate-evoked release of 3H-AA, while pHi acidification obtained by blockade of Na+/H+ and Cl-/HCO3- exchangers decreased the glutamate response. Membrane-bound phospholipase A2 (mPLA2) activity was stimulated by Ca2+ in a pH-dependent manner, increasing its activity as pH was shifted from 7.2 to 7.8. This pH profile corresponds to the pH profile of the glutamate-, NMDA- and kainate-evoked release of 3H-AA. Taken together, these results indicate that the glutamate-evoked release of 3H-AA may be mediated by the pH-sensitive mPLA2. Since excitatory neurotransmission mediated by glutamate results in both pHo and pHi changes and since AA enhances glutamatergic neurotransmission at both pre- and postsynaptic levels, the data reported here reveals a possible molecular mechanism whereby glutamate can modulate its own signalling efficacy in a pH-dependent manner by regulating the release of AA.

Glial receptors and their intervention in astrocyto-astrocytic and astrocyto-neuronal interactions

As shown on cultured astrocytes from the mouse, in the presence of adenosine deaminase, 2-chloroadenosine by acting on A1-adenosine receptors potentiated the activation of phospholipase C induced by the alpha 1-adrenergic agonist, methoxamine. This potentiation required the presence of external calcium and was blocked by pertussis toxin. Moreover, this potentiation resulted from a cascade of events: activation (by calcium and protein kinase C) of a phospholipase A2 coupled to A1-adenosine receptors, release of arachidonic acid, which inhibited the reuptake of glutamate into astrocytes and finally additional activation of phospholipase C by externally accumulated glutamate through metabotropic receptors. The effects of 2-chloroadenosine and methoxamine were respectively mimicked by somatostatin and substance P while endothelins reproduced the combined effects of 2-chloroadenosine and methoxamine. Conditioned media from treated astrocytes enriched in glutamate stimulated phospholipase C in cultured striatal neurones. In addition, glutamate alone was also found to stimulate phospholipase A2 in astrocytes through receptors exhibiting a pharmacological profile distinct from metabotropic receptors coupled to phospholipase C and the glutamate response was potentiated by ATP. Moreover, the neuronal arachidonic acid production evoked by glutamate was potentiated by acetylcholine. Finally, the combined application of 2-chloroadenosine and methoxamine on striatal astrocytes reduced the permeability of gap junctions between astrocytes and this response was mimicked by arachidonic acid. Together, these results emphasized the contribution of astrocytes in the regulation of glutamatergic transmission.

Glutamate-evoked release of arachidonic acid from mouse brain astrocytes

Brain astrocytes in primary culture from the rat or the mouse have been shown to possess ionotropic and metabotropic glutamatergic receptors. The activation of both types of receptors is responsible for a rise in the cytosolic concentration of calcium, while the stimulation of metabotropic receptors induces the accumulation of inositol phosphates. In the present study, it is demonstrated that in striatal astrocytes from mouse embryos, glutamate evokes a release of arachidonic acid. The nonionotropic receptors involved in this effect appeared to be pharmacologically distinct from those coupled to phospholipase C: (1) glutamate displayed different dose-response curves for the production of inositol phosphates (biphasic: EC50 = 25 and 300 microM) and the release of arachidonic acid (monophasic: EC50 = 200 microM); (2) L(+)-2-amino-4-phosphonobutyric acid (AP4) only antagonized the glutamate-evoked release of arachidonic acid without altering the production of inositol phosphates; (3) when used at a concentration of 0.1 mM, quisqualate induced a higher formation of inositol phosphates than glutamate (2 mM) while, in contrast to glutamate, it only weakly stimulated arachidonic acid release when used either at 0.1 mM or 1 mM. L(+)-2-amino-3-phosphonopropionic acid (AP3) suppressed both responses. The glutamate-evoked release of arachidonic acid seems to be oppositely regulated by protein kinases A and C. Indeed, the stimulation of adenylate cyclase by the beta-adrenergic agonist isoproterenol, vasoactive intestinal peptide, or pretreatment of striatal astrocytes with cholera toxin decreased the glutamate-evoked release of arachidonic acid. In contrast, ATP, which markedly stimulated inositol phosphate production, strongly potentiated the glutamate-evoked release of arachidonic acid.(ABSTRACT TRUNCATED AT 250 WORDS)

Role of arachidonic acid and glutamate in the formation of inositol phosphates induced by noradrenalin in striatal astrocytes

The noradrenalin-evoked production of [3H]inositol phosphates in mouse striatal astrocytes in primary culture appeared to be the result of the combined stimulation of alpha 1- and alpha 2-adrenergic receptors. Indeed, the noradrenalin (100 microM) response was only partially reproduced by a maximally effective concentration of methoxamine (100 microM), a selective agonist of alpha 1-adrenergic receptors. In addition, the noradrenalin (100 microM)-induced production of [3H]inositol phosphates, which was completely suppressed by the alpha 1-adrenergic antagonist prazosin (1 microM), was also partially inhibited by yohimbine, a selective antagonist of alpha 2-adrenoceptors (maximum inhibition = -57 +/- 11%, measured in the presence of 10 microM yohimbine; six experiments). Finally, UK14.304, a selective alpha 2-adrenergic agonist that was ineffective alone, enhanced the methoxamine-evoked production of [3H] inositol phosphates (EC50 = 86 +/- 21 nM; three experiments). These results suggest that the stimulation of alpha 1-adrenergic receptors is required for the alpha 2-adrenergic receptor-mediated enhancement of phospholipase C activity. The increased production of [3H]inositol phosphates resulting from the stimulation of alpha 2-adrenergic receptors involved pertussis toxin-sensitive G proteins (Gi/o) and depended on extracellular calcium. As shown using the fluorescent dye indo-1, noradrenalin (100 microM) induced a long-lasting increase in cytosolic calcium in striatal astrocytes. Moreover, noradrenalin (100 microM) stimulated [3H]arachidonic acid release from these cells. These two latter responses may result from synergistic effects due to the combined stimulation of alpha 1- and alpha 2-adrenergic receptors, because they were inhibited by either prazosin (1 microM) or yohimbine (10 microM). Finally, the noradrenalin-evoked production of [3H]inositol phosphates seems to result partly from an inhibition by arachidonic acid of glutamate uptake into astrocytes, leading to the stimulation of glutamate metabotropic receptors coupled to phospholipase C. Indeed, the alpha 2-adrenergic component of the noradrenalin response was suppressed by either enzymatic removal of external glutamate or addition of 2-amino-3-phosphonopropionic acid (1 mM), an antagonist of glutamate metabotropic receptors that blocked the glutamate-evoked production of [3H]inositol phosphates in striatal astrocytes, and was reproduced by the direct application of either glutamate or an inhibitor of glutamate uptake, beta-methyl-DL-aspartic acid.

Arachidonic acid stimulates glucose uptake in cerebral cortical astrocytes

Arachidonic acid (AA) has recently been shown to influence various cellular functions in the central nervous system. Here we report that AA increases, in a time- and concentration-dependent manner, 2-deoxy-D-[1-3H]glucose ([3H]2DG) uptake in primary cultures of astrocytes prepared from the cerebral cortex of neonatal mice. This effect is mimicked by an unsaturated fatty acid such as linolenic acid, while palmitic and arachidic acids, two saturated fatty acids, are inactive. Pharmacological agents that increase the endogenous levels of AA by stimulating AA release (melittin) or by inhibiting its reacylation (thimerosal) also promote [3H]2DG uptake by astrocytes. We also report that norepinephrine (NE) stimulates the release of [3H]AA from membrane phospholipids, with an EC50 of 3 microM; this effect is accompanied, with a temporal delay of approximately 4 min, by the stimulation of [3H]2DG uptake, for which the EC50 of NE is 1 microM. Since the cerebral cortex, the brain region from which astrocytes used in this study were prepared, receives a massive noradrenergic innervation, originating from the locus coeruleus, the effects of NE reported here further stress the notion that certain neurotransmitters may play a role in the regulation of energy metabolism in the cerebral cortex and point at astrocytes as the likely targets of such metabolic effects.

Blood magnesium, potassium, sodium, calcium and cortisol in drug-free depressed patients

Many biochemical variables, including plasma and erythrocyte magnesium, were simultaneously measured in drug-free depressed patients (n = 34), compared to healthy controls (n = 35). Higher plasma and erythrocyte magnesium concentrations were observed in patients than in controls (+12 per cent, P < 0.0001 and 14 per cent, P < 0.0001, respectively). In contrast, patients showed a lower plasma potassium level (-10 per cent; P < 0.007). Cortisol secretion was much higher in patients (+35 per cent; P < 0.02), particularly in females, showing overactivity of the hypothalamo-hypophyseo-adrenal axis in the patients. Except in a few cases, plasma sodium and calcium in patients did not differ from control values. Significant differences in magnesium and cortisol levels were observed between patients classified in diagnostic groups and by sex, whereas little variation in the other biochemical indices was noted. The increase in blood magnesaemia and its possible association with central hypocatecholaminergic deficiency in affective disorders are discussed.

Late results of reconstructive surgery for renovascular hypertension

In order to evaluate the late results of reconstructive surgery for renovascular hypertension, a review was made on a series of 120 consecutive patients who underwent operations over a 11 year period. There were 82 males (68.3%) and 38 females (31.7%) with a mean age of 48.4 years. Renal artery by-pass grafts were used in 90% (120/133), a thromboendarterectomy in 5.2% (7/133), and other surgical procedures were performed in 4.8% (6/133). Associated vascular procedures were performed in 38.3% (46/120) of patients. Operative mortality was 2.5% (3/120) overall; there was no mortality in the isolated renal artery reconstructions. There was a clinical success (after a mean follow-up of 48 months) in 80.4% of patients. The most important factors influencing clinical result after renal revascularization were: a generalized atherosclerosis (p less than 0.05), duration of hypertension (p less than 0.01) and the early post-operative response of the blood pressure (p less than 0.01). The overall five- and ten-year actuarial survival probabilities were 85 and 68%, respectively. The most common causes of death were myocardial infarction, stroke and cancer. Cox regression analysis for variables influencing survival indicated that persistence of severe hypertension was the major determinant of late survival (p less than 0.05). Hypertension in females is better tolerated, while younger patients appear to have better results and late survival after surgical treatment.

Lecithin: cholesterol-acyltransferase (LCAT) activity in alcoholic liver disease

The activity of LCAT (the controlling enzyme for cholesterol esterification in plasma) is known to be reduced in alcoholic cirrhosis, while little is known about early stage (liver steatosis) alcoholics. In this study, LCAT activity was assayed by Stokke and Norum's method, before and after a 15-day sobriety period, in liver steatosis and in cirrhosis alcoholics. Before alcohol withdrawal, LCAT activity was depressed in both groups. After the sobriety period, LCAT activity was significantly raised in liver steatosis patients, but was still lower than in controls; in cirrhosis patients, it was increased, but not significantly. According to our results, LCAT activity impairment in alcoholic liver disease is sustained by both the hypothesized mechanisms, alcohol-related metabolic disorders and lowered LCAT-enzyme production, but to different degrees, depending on the stage of the disease. In liver steatosis, metabolic disorders play a major role, as a liver-impairment-induced decrease in LCAT production seems rather unlikely, and increased LCAT activity is more likely to be sustained by metabolic normalisation than by any recovery of the damaged liver. However, the lack of improvement in about 20% of patients, and the fairly wide scattering of individual data, suggest a minor LCAT production impairment in liver steatosis too. In cirrhosis, the major role seems to be played by a permanent decrease in LCAT production, as no significant rise in LCAT activity was observed after alcohol withdrawal. However the restored LCAT activity observed in some patients could be related to improvement in the metabolic disorder, thus confirming the effectiveness of this mechnism in cirrhosis too.(ABSTRACT TRUNCATED AT 250 WORDS)