Coronary stenting and abciximab in primary angioplasty for ST-segment-elevation myocardial infarction

Advances in anti-platelet therapy and improvement of stent deployment techniques have improved the safety and efficacy of stenting in the setting of ST-segment-elevation myocardial infarction (STEMI). However, in randomized trials, routine coronary stenting does not reduce mortality and re-infarction, compared to balloon angioplasty. Further, the benefits in target vessel revascularization seem to be reduced when applied to unselected patients with STEMI. Direct stenting represents an attractive strategy with potential benefits in terms of myocardial perfusion. Future large randomized trials are needed to evaluate whether this strategy has a significant impact on outcome, and to provide a cost-benefit analysis of the unrestricted use of drug-eluting stents in this high-risk subset of patients. The additional use of abciximab reduces mortality in primary angioplasty. Since the feasibility of long-distance transportation has been shown in several randomized trials, early pharmacological pre-treatment may confer further advantages by early recanalization and shorter ischaemic time, particularly in high-risk patients. Further randomized trials are needed to clarify the potential benefits from early abciximab administration and the potential role of small molecules in primary angioplasty for STEMI.

[Transient erythroblastopenia in children: assessment of a hospital caseload]

Transient erythroblastopenia of childhood (TEC) is an acquired, self-limiting, uncommon disease, characterized by the temporary arrest of red cell production, resulting in moderate to several anemia. We retrospectively evaluated four cases of TEC, identified during an 8-year period of time in our Department of Pediatrics, including one patient, who developed TEC during the course of Kawasaki's syndrome. Clinical and hematological presentations of patients were analyzed and the most recent data of literature were reviewed. In conclusion, we suggest that a better knowledge of this rare and unique hematologic disorder of childhood may help make a correct diagnosis, avoiding unnecessary laboratory tests (e.g. bone marrow aspirate) and inappropriate therapeutic modalities.

Emergency medical services in mass gatherings: the experience of the Formula 1 Grand Prix 'San Marino' in Imola

Mass gatherings are special situations for which mass medical care must be preplanned. Acute emergencies occur at public gatherings and medical coverage on site has proven benefit. Responsibility of general plan, management of specific problems, transport planning, communications system, guidelines and protocols, special situations management, ancillary supports, sources of extra help for unforeseen needs are the most important items to consider. In mass gatherings the whole emergency medical service (EMS) planning and management has to depend on the emergency department direction, with its authority on all aspects of patient care in the EMS system. This report concerns the planning of EMS and of medical care in a situation at risk for mass casualties at the Formula I Grand Prix-Championship Racing 'San Marino' of Imola.

Multicenter study of Abbott AxSYM Digoxin II assay and comparison with 6 methods for susceptibility to digoxin-like immunoreactive factors

Performance characteristics of the Abbott nonpretreatment AxSYM Digoxin II assay were evaluated for quantification of digoxin at four independent sites. Correlation of digoxin measurements with the Abbott pretreatment AxSYM, Baxter Stratus II, Abbott TDx/ TDxFLx II, Abbott IMx, Emit 2000, and Beckman Synchron CX digoxin assays showed acceptable agreement, as indicated by: slope values > 0.84, r > 0.90, y-intercepts for all comparisons at or below the assay detection limit, and Sy/x ranging between 7.5% and 15.4% of the average digoxin value. Susceptibility to interference from digoxin-like immunoreactive factors (DLIFs) was examined in 233 samples from renal patients, liver disease patients, cord blood, and third-trimester pregnancies; the AxSYM Digoxin II assay demonstrated the least DLIFs interference. DLIF susceptibility for four of the methods was significantly greater (P < 0.05) than in the AxSYM Digoxin II assay; susceptibilities of the Stratus II and Emit 2000 methods were similar to the AxSYM Digoxin II assay.

Short- and long-term changes in striatal neurons and astroglia after transient forebrain ischemia in rats

BACKGROUND AND PURPOSE

The striatum is one of the regions most sensitive to transient forebrain ischemia. After 30-minute ischemia, areas of massive neuronal degeneration are clearly detectable a few hours after the insult and attain their maximal extension 24 hours after the insult. However, for most cellular and neurochemical parameters it is not known whether some recovery occurs at later times. We examined certain cell populations in the caudate putamen at different times after transient ischemia.

METHODS

Adult male Sprague-Dawley rats were subjected to 30-minute forebrain ischemia (four-vessel occlusion model). Six experimental groups were considered: control animals and ischemic animals killed 4 hours, 1 day, 7 days, 40 days, and 8 months after reperfusion. Three striatal cell populations were examined by means of immunocytochemistry coupled to computer-assisted image analysis: vulnerable medium spiny neurons, resistant aspiny neurons, and reactive astrocytes, labeled for their content of dopamine- and cAMP-regulated phosphoprotein mr32 (DARPP-32), somatostatin and neuropeptide Y, and glial fibrillary acidic protein, respectively.

RESULTS

(1) The area containing DARPP-32 immunoreactive neurons was markedly decreased (15% to 20% of control caudate putamen area) at 1 day after reperfusion and partially recovered at the following times (40% to 50% at 7 days and 50% to 60% at 40 days and 8 months after reperfusion). (2) The appearance of reactive astrocytes was precocious (4 hours to 1 day after ischemia) in the medial caudate putamen, the region in which DARPP-32 recovered within 40 days after ischemia, and late (7 to 40 days after ischemia) in the lateral caudate putamen, where no DARPP-32 recovery was detected. (3) Neuropeptide Y/somatostatin-containing neurons resisted the ischemic insult and could be detected in areas devoid of DARPP-32 immunoreactive neurons as long as 8 months after reperfusion.

CONCLUSIONS

The present results show a marked recovery of DARPP-32-positive neurons within 40 days after 30-minute forebrain ischemia in the medial, but not the lateral, caudate putamen. Medial caudate putamen also contains a high density of reactive astrocytes on the first day after ischemia, suggesting that astrocytic support has an important role in the spontaneous recovery of ischemic neurons.

Cabergoline in the treatment of early Parkinson's disease: results of the first year of treatment in a double-blind comparison of cabergoline and levodopa. The PKDS009 Collaborative Study Group

Cabergoline is a potent D2 receptor agonist with a half-life of 65 hours that may provide continuous dopaminergic stimulation administered once daily. In this study, we randomized de novo Parkinson's disease (PD) patients to treatment with increasing doses of cabergoline (0.25 to 4 mg/d) or levodopa (100 to 600 mg/d) up to the optimal or maximum tolerated dose. Decreases of > 30% in motor disability (Unified Parkinson's Disease Rating Scale Factor III) versus baseline were considered indicative of clinical improvement. If 30% improvement was not achieved, levodopa/ carbidopa could be added on an open basis. Of the 208 patients entered in the cabergoline group, 175 remained in the study for 1 year at a mean dose of 2.8 mg/d; in the levodopa group, 176 of the 205 patients entered were still on study after 1 year at a mean dose of 468 mg/d. The proportion of patients requiring additional levodopa/carbidopa increased in the cabergoline group from 18% at 6 months to 38% at 1 year versus 10% (p = 0.05) at 6 months and 18% (p < 0.01) at 1 year in the levodopa group. The proportion of patients showing clinical improvement did not differ significantly between the two groups, or between the subgroups on monotherapy, at any endpoint. Irrespective of levodopa/carbidopa addition, 81% of patients in the cabergoline group and 87% of patients in the levodopa group were clinically improved at 1 year (p = 0.189); the corresponding figures for the subgroup on monotherapy were 79% in the cabergoline-treated patients and 86% in the levodopa-treated patients (p = 0.199). The mean difference versus baseline in Unified Parkinson's Disease Rating Scale Factor III scores in patients who remained on monotherapy up to 1 year was 12.6 (95% confidence interval [CI]: 10.8, 14.3) in the cabergoline group and 16.4 (95% CI: 14.8, 18.0) in the levodopa group. Adverse events occurred in 76% of patients on cabergoline and in 66% of patients on levodopa. The severity profile for reported events was similar for the two agents. The results of this study indicate that cabergoline treatment for up to 1 year is only marginally less effective than levodopa in the proportion of patients who can be treated in monotherapy. More than 60% of de novo PD patients could be managed on cabergoline alone up to 1 year. In the patients in whom levodopa/carbidopa was needed, the combination therapy provided efficacy similar to that obtained with levodopa alone, with a relevant sparing of levodopa.

Cryoprostatectomy consistently elevates serum creatine kinase-MB isoenzyme

STUDY OBJECTIVE

To measure serum CK-MB, a market of myocardial infarction (MI), in elderly men before and after cryoprostatectomy.

DESIGN

Serum CK-MB was measured on each patient before and after cryoprostatectomy. Each patient's preoperative result was used as control measurement for comparison with measurements made after cryoprostatectomy.

SETTING

Inpatient operating room and postanesthetic recovery unit of a university-affiliated general hospital.

PATIENTS

38 male patients, mean (SEM) age 69.1 +/- 1.4 years, undergoing cryoprostatectomy.

INTERVENTIONS

All patients had a 12-lead ECG prior to surgery, in the recovery room, and 24 hours after surgery. Serum CK-MB was measured prior to induction of anesthesia, on arrival in the recovery room, and at 8 and 24 hours after surgery. Lactate dehydrogenase (LDH) and isoenzymes also were measured in 10 patients before and after cryoprostatectomy.

MEASUREMENTS AND MAIN RESULTS

All patients underwent uneventful cryoprostatectomy. No patients had new ECG changes after surgery. All patients had normal serum CK and CK-MB concentrations before surgery. Serum CK and CK-MB were significantly elevated after cryoprostatectomy (p < 0.001). Enzyme values were greatest 8 hours after surgery: total CK mean 1453 +/- 145 U/L (range 199 to 3,356 U/L); CK-MB mean 52 +/- 3 ng/ml (range 12 to 114 ng/ml) or 5.0 +/- 0.5% of total CK (range 1.6% to 12.4%). All patients had significant elevations of LDH after cryoprostatectomy but did not show an increase in the ratio of LDH1 to LDH2 isoenzymes. Finally, unlike patients with an acute MI, the activity of CK-MB isoenzyme when measured by gel electrophoresis was two to three times greater (mean, 2.6 +/- 0.7) than the concentration measured with the monoclonal antibody assay in patients after cryoprostatectomy.

CONCLUSION

Serum CK-MB is an unreliable test to diagnose an MI in patients who have undergone cryoprostatectomy.

Acute effects of TTFCA on capillary filtration in severe venous hypertension

The acute variation in capillary filtration [CF] was evaluated with strain-gauge plethysmography in patients with severe venous hypertension due to deep venous disease. Two groups were selected and randomly treated with a single oral dose or TTFCA (60 mg or 120 mg). CF was assessed again after 5 and 10 hours. Eleven patients were randomised in the 60 mg group and 9 in the 120 mg group. Also 5 normal subjects were studied with the same procedure to act as controls. No variations in CF were observed in normal limbs. In both groups of patients there was a significant decrease in CF after 5 and 10 hours. The percent decrease in CF after 10 hours was higher in the high dose group. These results indicate that TTFCA is acutely effective in reducing CF and oedema in subjects with venous hypertensive microangiopathy. The effects of TTFCA on CF appear to be dose related.

[The microcirculatory activity of Centella asiatica in venous insufficiency. A double-blind study]

In 87 patients with chronic venous hypertensive microangiopathy the efficacy of oral FTTCA (Centella asiatica) administered for 60 days was tested. The microcirculatory effects of two dosages (30 mg bid and 60 mg bid) versus placebo was assessed in a double blind study. The compound was well tolerated and no unwanted effects were observed. Microcirculatory parameters--peri-malleolar skin flux at rest (RF) and transcutaneous PO2 and PCO2--improved as did the abnormally increased RF, PCO2 decreased and PO2 increased in comparison with values measured at inclusion. These results confirm the efficacy of FTTCA in venous hypertensive microangiopathy. Furthermore the effects of FTTCA appear to be dose-related.

Involvement of alpha 2-receptors in the analgesia induced by transient forebrain ischemia in rats

Transient forebrain ischemia induced in rats by the four-vessel occlusion method produced analgesic effects in the hotplate test that persisted for 2 weeks. Ischemia-induced analgesia was attenuated by low doses of alpha 2-agonist clonidine (0.01-0.10 mg/kg, IP) and enhanced by low doses of alpha 2-antagonists yohimbine (1-2 mg/kg, IP) and idazoxan (0.25-1.00 mg/kg, IP) administration 7 days after ischemia. Ischemia-induced analgesia was not affected by methysergide, naloxone, propranolol, or phenoxybenzamine administered 7 days after ischemia, when motor control and arousal level of rats recovered to normal conditions. The enhanced response to yohimbine was antagonized by pretreatment with clonidine (0.75 mg/kg, IP) and naloxone (10 mg/kg, IP), suggesting the involvement of endogenous opioid peptides. The enhanced response to yohimbine was still present 2 months after ischemia, when preischemic hotplate threshold was restored. As alpha 2-agonists reduce and alpha 2-antagonists increase the outflow of central noradrenaline, it is suggested that activation of central noradrenergic systems is involved in the mediation of ischemia-induced analgesia.

Effects of polyamine synthesis blockade on neuronal loss and astroglial reaction after transient forebrain ischemia

Polyamines and ornithine decarboxylase, the polyamine biosynthetic enzyme, have been demonstrated to increase in the early phase of several types of brain lesion. However, their role in the pathogenesis of tissue damage is still debated. In the present paper the effects of treatments with alpha-difluoromethylornithine, a suicide inhibitor of ornithine decarboxylase, have been investigated in a model of transient forebrain ischemia. Three treatment schedules were used: alpha-difluoromethylornithine treatment was either started 3 hr before and repeated 1 hr after the insult, or started at the time of the insult and continued for 3 or 7 days after post-ischemic reperfusion. The rats were sacrificed 4 hr, 7 or 40 days after reperfusion, respectively. The acute experiment demonstrated that alpha-difluoromethylornithine can reduce the increase of glial fibrillary acid protein immunoreactivity, an early marker of astroglial reaction, in ischemic striatum. Subchronic and chronic alpha-difluoromethylornithine treatments induced a worsening of the morphological outcome of the ischemic lesion. In caudate-putamen a trend for an increase of the area of neuronal loss was present after both treatments. In the hippocampal formation, a significant increase in the severity of neuronal lesion was observed in the mildly lesioned CA3 field. In addition, other alterations of lesioned tissue were observed in alpha-difluoromethylornithine-treated animals, including increases of non-neuronal cells at 7 and especially 40 days post-lesion in striatum and CA3 hippocampal field. In conclusion, present data indicate that ornithine decarboxylase activation after ischemic lesion is a crucial factor for survival of mildly lesioned neurons and proper tissue reaction to the ischemic lesion. The experiment on acute alpha-difluoromethylornithine treatment suggests that these effects may be, at least in part, related to putrescine-induced activation of astroglial cells in the early post-lesion period.

Detection of free radicals during brain ischemia and reperfusion by spin trapping and microdialysis

Extracellular free radicals were detected in rat striatal perfusate samples by intracerebral microdialysis coupled to the spin trapping technique. Five Sprague-Dawley rats were subjected to 30 min of global ischemia followed by reperfusion; throughout the experimental period the intrastriatal dialysing probe was perfused with Ringer's solution containing the spin trap agent pyridyl-N-oxide-t-butylnitrone (100 mM) together with the iron chelating agent diethylentriaminepentacetic acid (100 microM). A radical adduct occurred during ischemia and early reperfusion, but not in basal conditions; the spin adduct was characterized as a carbon centered radical, consistent with the presence of an oxidative attack on membrane lipids. The direct evidence of the formation of free radicals supports the hypothesis that free radicals play a role in the pathogenesis of the histological damage during brain ischemia.

Siagoside selectively attenuates morphological and functional striatal impairments induced by transient forebrain ischemia in rats

BACKGROUND AND PURPOSE

Transient forebrain ischemia induced in rats by the four-vessel occlusion method is known to produce severe neural damage in the hippocampus and striatum and a behavioral syndrome the major symptom of which is a working memory deficit. Recent evidence suggests that monosialogangliosides can ameliorate postischemic symptoms. Our purpose was to study the effect of siagoside, the inner ester of GM1 ganglioside, on some behavioral and morphological impairments induced by four-vessel occlusion in rats.

METHODS

Rats were injected daily with 5 mg/kg i.p. siagoside starting 4 hours after the cerebral ischemia. After 14 days the rats were tested for working memory in a water T maze or scored for apomorphine-induced stereotypy. The rats were killed 21 days after the cerebral ischemia. Histological and computer-assisted morphometric analyses were performed on cresyl violet-stained brain sections, which were graded according to a neuropathologic score, and on sections stained with a monoclonal antiserum against dopamine and cyclic adenosine-3',5'-monophosphate-regulated phosphoprotein, a marker for striatal dopaminoceptive neurons.

RESULTS

Siagoside treatment reduced the stereotypy score induced by low doses of apomorphine and the extent of striatal lesions but did not affect the working memory deficit or the extent of hippocampal lesions.

CONCLUSION

Daily siagoside treatment after acute cerebral ischemia attenuates some morphological and functional deficits related to striatal damage. These effects can be interpreted as a selective protective action on striatal neural populations or as a modulatory action on neural systems involved in striatal control. These data are consistent with preliminary clinical reports showing that monosialogangliosides enhance motor recovery after acute ischemic stroke.

[Efficacy of TTFCA in reducing the ratio between lymphatic and plasma protein concentration in lymphatic and postphlebitic edema]

In subjects with lymphatic problems and postphlebitic edema there is a significant difference in the ratio between lymphatic and plasma concentration of protein (CL/CP) in the foot. Two groups of patients were studied (one group with lymphedema and the other with postphlebitic limbs) in order to assess the CL/CP ratio before and after TTCFA treatment (Centellase). The study confirmed the efficacy of treatment in achieving a significant reduction of CL/CP and distal edema.

The endurance triathlon: metabolic changes after each event and during recovery

We analyzed metabolic parameters in 11 volunteers after each segment of an endurance triathlon and, in a separate year, analyzed similar parameters in eight volunteers during 6 d of recovery following completion of an endurance triathlon. After the 2.4-mile ocean swim, serum lactate tripled, and albumin and muscle enzymes were increased. After the 112-mile bicycle ride, mild dehydration occurred, and muscle enzymes and uric acid levels increased markedly. Serum lactate was elevated over baseline but was lower then after the swim. After the 26.2-mile run, dehydration and muscle damage progressed; serum triglycerides dropped by 50%. Serum lactate remained elevated, but less than after either of the other segments. During recovery, muscle enzymes continued to rise and peaked (creatine phosphokinase on the day following the triathlon at 4920 +/- 685 U.ml-1; range 1321-16,746); creatine phosphokinase and lactate dehydrogenase remained significantly elevated at the end of the recovery period. Total protein and albumin decreased, suggesting alterations in their synthesis or their utilization for tissue repair. Serum cholesterol levels fell significantly until the 4th d. Serum triglycerides slowly increased to baseline over 4 d, suggesting their use as energy substrate during recovery. Thus, competition in an endurance triathlon causes skeletal muscle injury that appears early, increases as the triathlon progresses, and is still apparent even 6 d after completion of the triathlon. Changes in plasma proteins and lipid suggest that energy substrate utilization is shifted as the triathlon progresses and as the body repairs itself following completion of the event.

Decrease in mRNA levels but not in the density of D2 dopamine receptors in rat striatum after transient forebrain ischemia

D2 dopamine receptor mRNA was analyzed by in situ hybridization histochemistry in rat striatum 7 days after transient forebrain ischemia. A patchy disappearance of the D2 receptor mRNA was observed in the dorsolateral striatum. In the same area, a disappearance of D1 binding sites occurred in the absence of significant changes in D2 receptor density. These results suggest that, although D2 receptors seem to be apparently unaffected after forebrain ischemia, a long-lasting impairment of their neosynthesis may be present in striatal D2 dopaminoceptive neurons.

Changes in striatal mu and delta opioid receptors after transient forebrain ischemia: a quantitative autoradiographic study

Transient forebrain ischemia induces specific changes in several neurochemical markers in the dorsolateral striatum. In the present paper, the density and distribution of mu and delta opioid receptors were analyzed in rat striatum 7 days after 30 min forebrain ischemia using the 4-vessel occlusion model. A marked (about 70%) decrease in the density of both opioid receptor subtypes was found in the dorsolateral striatum overlapping the areas of histological damage and of D1 dopamine receptor disappearance. Moreover, the density of delta opioid receptors and of the diffuse mu opioid receptors was also affected (30% decrease) in the ventromedial striatum, an area which is substantially spared by the ischemic lesion. In contrast, the striatal patches of mu opioid receptors were not affected in the ventro-medial striatum and were preserved to a large extent in the area of lesion, although their area and receptor density resulted markedly reduced. The impairment of both opioid receptor subtypes suggests that opiate systems, like dopaminergic systems, are involved in the neurochemical changes observed in the striatum after transient forebrain ischemia.

Microdialysis and luminescent probe: analytical and clinical aspects

Immobilized enzymes are widely used in the clinical laboratory to assay several analytes and enzymes. The use of immobilized enzymes makes these reagents recoverable, disposable and in most cases increases their stability and catalytic activity. In conjunction with bioluminescent enzymes (firefly and bacterial luciferases) and chemiluminescent catalyst (peroxidase) we set up high-sensitive flow sensors based on the use of nylon tube coil or epoxy methacrylate column as solid support. For in-vivo determination a suitable microdialysis probe inserted directly into brain or blood allows continuous measurement of extracellular lactate levels by means of a bioluminescent flow detector system. This procedure performs more measurements in the same time interval than other systems (HPLC), e.g. to give a detailed description of the effects of ischemia, or other pathological events, on lactate concentration in the brain.

Evidence for a role of neosynthetized putrescine in the increase of glial fibrillary acidic protein immunoreactivity induced by a mechanical lesion in the rat brain

The effect of alpha-difluoromethylornithine (alpha-DFMO), an irreversible inhibitor of ornithine decarboxylase (ODC) the rate limiting enzyme of polyamine biosynthesis, was studied on the astroglial reaction in a model of mechanical brain injury. alpha-DFMO markedly decreased the astroglial activation induced by the microdialysis probe implantation in the striatum of the male rat, as studied by glial fibrillary acidic protein (GFAP) immunocytochemistry. This response was restored by putrescine (20 nmol/ml) administered via the microdialysis probe. These results suggest that the astroglial reaction and the polyamine biosynthesis activation induced by a localized mechanical lesion are causally linked phenomena.

Improvement of capillary permeability in patients with venous hypertension after treatment with TTFCA

The VSC (vacuum suction chamber) device, a new system to evaluate local capillary permeability, was used with laser Doppler flowmetry to study variations of permeability and of the microcirculation in 10 normal subjects; in 22 patients with moderate, superficial venous hypertension; and in 12 patients with postphlebitic limbs and severe venous hypertension. All these patients had distal (ankle and foot edema) in the evening. After a first assessment these subjects were studied again after two weeks without treatment and after two weeks' treatment with total triterpenic fraction of centella asiatica (TTFCA), tablets, 60 mg, tid. The VSC produces a wheal on the skin of the perimalleolar region that disappears (in average) in less than sixty minutes in normal subjects. The disappearance time (DT) is greater in conditions of increased capillary filtration and permeability. The three groups of subjects (normal and those with superficial and severe venous hypertension) had significantly different, increasing disappearance time of the wheals at the first observation. There were no significant changes after two weeks' observation, but after 2 weeks' treatment with TTFCA, there was a significant decrease of DT both in limbs with superficial and with deep venous incompetence. The improvement (decrease) of the abnormally increased capillary permeability was associated with a significant improvement of the microcirculation and symptoms (studied by an analogue scale line). In conclusion this study showed a combined improvement of the microcirculation and capillary permeability after treatment with TTFCA and the possibility of using the VSC to evaluate the effects of drugs (or other treatment) on local capillary permeability in patients with venous hypertension.

Cellular and synaptic alterations in the aging brain

The morphological and functional impairments observed in the aging brain are discussed in the framework of theoretical concepts, such as the existence of different modalities of intercellular communication and of specific trophic features in the central nervous system. The relevance of changes at the cellular level (disappearance of neuronal cell bodies and proliferation of astroglial cells) and at the synaptic level (alterations in neurotransmitter and receptor levels) is discussed. Two, non-mutually exclusive hypotheses are advanced to explain the frequent absence of correlation between neuropathological findings and functional deficits in aged patients. According to the first, the physiological reshaping of brain circuits during aging may lead to "wrong" readjustments of neural networks (e.g. due to less effective endogenous and exogenous orienting signals) causing minor morphological alterations but marked functional deficits. The second hypothesis maintains that the absence of correlation between neuropathological and functional deficits is due to the impairment of restricted neuronal populations ("pacemaker and command neurons") which play a special role in the hierarchical organization of neuronal networks. These neurons (inter alia, peptidergic neurons) may also be involved in volume transmission (diffusion of electrical and chemical signals in the extracellular fluid to reach distant targets). Moreover, the relevance of glial cells, not only as regulators of the extracellular medium but also on the basis of their trophic links with neurons, is considered. Finally, the interplay between trophic factors and therapeutical experience for the maintenance and/or recovery of an impaired function in elderly patients is discussed.

On the role of neuropeptide Y in information handling in the central nervous system in normal and physiopathological states. Focus on volume transmission and neuropeptide Y/alpha 2 receptor interactions

The NPY neurons play an important role in information handling in the CNS by their ability to interact in both wiring and volume transmission at the network, local circuit and synaptic level. The importance of NPY/alpha 2 receptor-receptor interactions in cardiovascular, neuroendocrine and vigilance control is emphasized. Alterations in these receptor-receptor interactions take place in the spontaneously hypertensive rats as well as in the ischemic brain, which may have profound consequences for the information handling and contribute to the functional alterations found in these pathophysiological states. Finally, in the aging brain there appears to exist a marked reduction in NPY transmission line, which may affect higher brain functions, such as learning and memory retrieval. The most impressive result is, however, the indications of a role for NPY in volume transmission, where NPY appears to produce syndromic actions via its conversion into biologically active fragments, which may have preferential actions at Y2 NPY receptors. These syndromic pathways may be altered in the spontaneously hypertensive rat and may be controlled by gonadal steroids and glucocorticoids. Glucocorticoid receptors have been demonstrated in all arcuate NPY neurons and all NA/NPY and A/NPY costoring neurons.