Influence of Nonsulfated Polysaccharides on the Properties of Electrospun Poly(lactic-co-glycolic acid) Fibers.

Biomimetic tissue engineering aspires to develop bioinspired implantable devices that would positively interact with the host. Given that glycosaminoglycans are involved in many physiological processes, whereas their deprivation is associated with pathophysiologies, functionalization of implantable devices with natural and/or synthetic carbohydrate moieties is at the forefront of scientific research and industrial innovation. Herein, we venture to assess the influence of various concentrations (0.01%, 0.1%, 1%) of hyaluronic acid and Ficoll on the structural, thermal, biomechanical and biological (human osteoblasts) properties of electrospun poly(lactic-co-glycolic acid) fibers. The addition of hyaluronic acid and Ficoll reduced the fiber diameter, with the 1% hyaluronic acid exhibiting the smallest fibers diameter (p < 0.001). Neither the addition of hyaluronic acid nor the addition Ficoll significantly affected the onset and peak temperatures (p > 0.05). All hyaluronic acid and Ficoll treatments significantly reduced stress at break, strain at break and elastic modulus values (p < 0.001). Hyaluronic acid and Ficoll did not affect osteoblast viability and metabolic activity temperatures (p > 0.05); the 1% hyaluronic acid and Ficoll significantly increased (p < 0.001) osteoblast proliferation at day 21. By day 21, the 1% hyaluronic acid and 1% Ficoll fibers showed the highest alkaline phosphatase activity and calcium deposition. At day 21, osteocalcin was not detected, whereas osteopontin was detected on all samples. Collectively, our data clearly illustrate the biological benefit of nonsulfated polysaccharides as functionalization molecules.

Serotonin modulation of cell excitability and of [3H]GABA and [3H]D-aspartate efflux in primary cultures of rat cortical neurons.

The effects of 5-hydroxytryptamine (5-HT) on neuronal excitability, evaluated as depolarization-induced firing rate, and on amino acid release, measured as electrically-evoked [(3)H]GABA and [(3)H]d-aspartate efflux, were investigated in rat primary cortical neuronal cultures. 5-HT displayed a concentration-dependent, bimodal effect on neuronal excitability: at 3-10microM it increased excitability through 5-HT(2A) receptors, and was blocked by the selective 5-HT(2A) antagonist MDL 100907, whereas at 30-100microM it reduced excitability through 5-HT(1A) receptors, and was, in turn, blocked by the selective 5-HT(1A) antagonist WAY 100135. The electrically-evoked [(3)H]GABA efflux was concentration-dependently inhibited by 5-HT (pEC(50)=4.74) and such inhibition was prevented by WAY 100135, but not by GR 55562, a selective 5-HT(1D/B) receptor antagonist. Conversely, 5-HT concentration-dependently increased stimulus-evoked [(3)H]d-aspartate efflux (pEC(50)=4.71). The increase was facilitated by methiothepin and was reversed into inhibition by ICS 205930, a selective 5-HT(3) receptor antagonist. In the presence of ICS 205930, the inhibition induced by 5-HT was prevented by the selective 5-HT(1D/B) receptor antagonist GR 55562, but not by WAY 100135. These findings suggest that 5-HT inhibits GABA release through 5-HT(1A) receptors and exerts a dual modulation on glutamate release, mostly facilitatory (through 5-HT(3) receptors) but also inhibitory (through 5-HT(1D/B) receptors), leading to a prevalently positive modulation of the excitatory signal by amino acid neurotransmitter containing neurons.

Effects of nociceptin/orphanin FQ and endomorphin-1 on glutamate and GABA release, intracellular [Ca2+] and cell excitability in primary cultures of rat cortical neurons.

The effects of nociceptin/orphanin FQ (N/OFQ) and endomorphin-1 (EM-1) on glutamate and GABA release, intracellular calcium, neuronal excitability and glutamate current were investigated in rat primary cortical neuronal cultures. Through their specific receptors N/OFQ and EM-1 (0.02-1 microM) inhibited the electrically evoked outflow of [3H]D-aspartate at most to -50% and that of [3H]GABA to -30%. In addition, at 1 microM, both peptides induced a decrease of the firing rate caused by electrical depolarization. N/OFQ 1-10 microM did not influence either the electrically evoked calcium influx or the glutamate-evoked currents, whereas EM-1 1 microM significantly inhibited them. Thus, in cortical neurons in culture, both N/OFQ and EM-1 inhibited the secretory process and neuronal excitability but EM-1 also affected calcium influx and cell body responsiveness to glutamate. Consequently, EM-1 appeared to dampen this excitatory signal more then N/OFQ did.

The nicotinic modulation of [(3)H]D-aspartate outflow in primary cultures of rat neocortical neurons: effect of acute and long term nicotine treatment.

The effect of nicotine 1 nM-10 microM on the efflux of [(3)H]D-aspartate was tested in primary cultures of rat cortical neurons kept at rest and subjected to electrical field stimulation. Two trains of pulses at 20 Hz for 20 s were applied at the 60th (St(1)) and 90th (St(2)) min of perfusion. The drug slightly and transiently increased the efflux of resting cells while, when given during St(2), it greatly enhanced the electrically evoked efflux estimated as St(2)/St(1) ratio, EC(50) being 107 nM. The nicotinic receptors (nAChR) giving rise to this positive modulation were partly mecamylamine- and partly alpha-bungarotoxin-sensitive. They appeared to be located at the nerve endings since nicotine facilitation was only slightly prevented by tetrodotoxin during depolarisation with 15 mM KCl. Pretreatment with glutamate antagonists did not reveal any interaction between nAChR and ionotropic glutamate receptors. Membrane glutamate carrier involvement in the nicotine effect was ruled out. Long-term treatment with nicotine 1 microM (from the 3rd-4th to the 8th-9th day in vitro) reduced the maximal response to the drug but shifted its threshold concentration to the left (from 10 nM to 1 nM), leaving the contribution of the two receptor subtypes unchanged. Reduced responsiveness to nicotine was also evident in long-term treated cerebellar granule cells. In conclusion, presynaptic nAChR's, both containing and lacking alpha(7) subunits, can contribute to enhance the glutamatergic secretion in primary cultures of rat cortical neurons, chiefly during electrical stimulation.

Nicotinic modulation of [(3)H]D-aspartate outflow from cultured cerebellar granule cells.

The effect of nicotine on basal and electrically evoked (20 Hz for 20 sec) [(3)H]D-aspartate efflux (assumed as an index of transmitter release) was studied in rat cerebellar granule primary cultures. Nicotine (10-100 nM) increased the basal efflux two to three times and concentration-dependently enhanced the electrically evoked efflux up to ten times. Higher drug concentration (1 microM) underwent rapid desensitization. Facilitation of the efflux was similarly reduced by the nicotinic acetylcholine receptor antagonists, alpha-bungarotoxin and mecamylamine, suggesting the involvement of at least two receptor subtypes containing and lacking alpha(7) subunits, respectively. Since the increased efflux induced by nicotine in granule cells kept at rest or depolarized by KCl 15 mM was antagonized by tetrodotoxin, the involvement of sodium channels by receptors located at preterminal sites was suggested. Taken together, these findings emphasize the role of the cholinergic input in granule cell function and in glutamatergic signaling.

High sensitivity bioassay of paralytic (PSP) and amnesic (ASP) algal toxins based on the fluorimetric detection of [Ca(2+)](i) in rat cortical primary cultures.

A high sensitivity bioassay able to recognise small amounts of paralytic and amnesic toxins in algal acetic extracts is described. The method is based on the measure of intracellular [Ca(2+)](i) in primary cultures of rat cortical neurones preloaded with Fura-2 and submitted to electrical field stimulation. Under normal conditions the basal [Ca(2+)](i) level was about 50-100 nM and was nearly doubled during the peaks induced by trains of electrical pulses at 10 Hz for 10 s. Saxitoxin (STX) 3.5 nM and tetrodotoxin (TTX) 24 nM halved the peaks height without affecting basal [Ca(2+)](i). Conversely, domoic acid increased the basal [Ca(2+)](i) (EC(50)=3. 7 microM) and decreased the calcium peaks (EC(50)=7.3 microM). CNQX (a competitive antagonist of AMPA/KA receptors) at 10 microM shifted to the right by a factor of 3 the concentration-response curves of domoic acid. The extracts of non-toxic algae were well tolerated by up to 10 microg protein/ml, whereas extracts of Alexandrium lusitanicum at 1-4 microg protein/ml reduced [Ca(2+)](i) peaks and increased basal calcium levels. This toxic effect of A. lusitanicum was unexpected since parallel HPLC analysis showed only the presence of gonyautoxins, known to act like saxitoxin. Therefore, the bioassay on rat cortical neurones revealed a complex composition of the toxins present in A. lusitanicum. The relevance of fluorimetric detection of [Ca(2+)](i) in primary neuronal cultures in the evaluation of algal risk is stressed.

Evidence for an in vivo and in vitro modulation of endogenous cortical GABA release by alpha-glycerylphosphorylcholine.

The effects of alpha-glycerylphosphorylcholine (alpha-GPC) on endogenous cortical GABA release were studied both in vivo and in vitro. In freely moving rats, equipped with epidural cups, alpha-GPC (30-300 mg/kg i.p.) increased GABA release. This effect was potentiated by atropine, both systematically administered (5 mg/kg i.p.) and locally applied (1.4 microM), but not by mecamylamine (4 mg/kg i.p.). The alpha-GPC-induced increase in GABA release was abolished in rats pretreated with the alpha 1 receptor antagonist prazosin (14 micrograms/kg i.p.). In cortical slices alpha-GPC (0.4 mM) increased the spontaneous GABA efflux. This effect was abolished by tetrodotoxin (0.5 microM) and prazosin (1 microM), but not by atropine (0.15 microM) or mecamylamine (2.5 microM). These results indicate that the facilitatory response by alpha-GPC on GABA release does not depend on a direct activation of either muscarinic or nicotinic receptors, but suggest the involvement of the noradrenergic system.

[Chiari's network: persistence of the embryonic remnants of the valve of the sinus venosus in the right atrium. Echocardiographic and clinical analysis in a group of subjects]. / La rete di Chiari: persistenza dei residui embrionali delle valvole del seno venoso in atrio destro. Analisi ecocardiografica e clinica in un gruppo di soggetti.

As echocardiography is being used more often, its value and accuracy are becoming more fully appreciated, especially for identifying normal anatomic variants and their possible erroneous interpretation as pathologic states. We report the echocardiographic and clinical findings observed in sixteen subjects examined at our Cardiological Service in the period from January 1987 to April 1988. Mean age of these subjects is 40 +/- 27.04. Of these subjects, six are affected by other cardiac pathologies and ten are unaffected (Group A). First, we describe in all the patients M-mode and two dimensional patterns of persistence of the right venous sinus valve known as the Chiari network. This structure can present as a highly mobile, highly reflective echo target, which can be seen especially by means of the bi-dimensional technique. The Chiari network could be seen with all four standard approaches. The two most diagnostic views are, in our experience, the short axis parasternal view (62.5%), and the subcostal view (87.5%). In a great number of subjects (75%) the Chiari network could be seen in at least two approaches. Second, in Group A we make a clinical examination. Nine subjects in this group show the presence of a cardiac systolic murmur with vibratory characters from grade 1/6 to grade 3/6. 50% of the same patients presented supraventricular arrhythmias (particularly, two presented reciprocating paroxysmal supraventricular tachycardia and one paroxysmal atrial fibrillation). The significance of these findings is not clear yet. We, at least, emphasise that the Chiari network could be confused with other curvilinear highly mobile, echo targets such as right-heart vegetations, flail tricuspid leaflets, a small right-heart thrombus or even a pedunculated right heart tumor (especially right atrial myxoma). On the contrary, this structure might be considered a "normal anatomic variant".

[Dynamic left intraventricular obstruction in acute myocardial ischemia]. / Ostruzione dinamica intraventricolare sinistra in corso di ischemia miocardica acuta.

A case of a 60-year-old woman suffering from hypertension, who presented an episode of acute myocardial ischemia with an elevation of the ST segment in the anterior ECG lead, is reported. On examination, a transient loud systolic murmur was present; it completely disappeared soon after the cessation of acute myocardial ischemia. Doppler echocardiography was performed a few times, during and after the acute ischemia: it was able to show a sort of "hour-glass" deformation of the left ventricle due to the akinesia of the anterior and apical segments. This functional anatomic deformation hampers the outflow from the left ventricle thus creating a dynamic left intraventricular gradient, which is clearly shown by pulsed wave and continuous Doppler echocardiography.

[The hospitalized drug addict. Social assistance and therapeutic care]. / Il tossicodipendente ospedalizzato. Aspetti socio-assistenziali e terapeutici.

Ninety drug addicts observed in 1973-83 were examined in a study of the main anamnestic and behavioural parameters, the reasons for hospitalisation, the presence of withdrawal symptoms during treatment and any prospects of long-term cure. In conclusion, it is emphasised that the low frequency of real withdrawal pathology often renders "scaled" treatment with methadone superfluous. Finally it is pointed out that in itself, the hospitalisation period can do almost nothing to break the addiction spiral unless it forms part of a wider prospect of global treatment.

[Iodine and delayed immunity]. / Iodio e immunità ritardata.

Iodine was and is sometimes used therapeutically in various pathologies where the immune mechanism is known to play a dominant role. It has in fact been administered to patients with tubercular granulomatous, lepromatous, syphilitic and mycotic lesions where it facilitates cure. This effect does not depend on iodine's action on the micro-organism responsible. Iodine may also be used in Villanova-Panol Panniculitis, in erythema nodosum, in nodular vasculitis, erythema multiforme and Sweet's syndrome. Oral iodine is also very effective in the lymphatic-cutaneous form of sporotrichosis. In order to establish a relationship between dietary iodine and immune response, 607 infants residing in an area of endemic goitre were studied: 215 were given Lugol solution (2 drops a week for about 8 months) and 392 not. The immune response was assessed by the skin test method using tetanic toxoid and a clear correlation was shown between this and lymphocyte stimulation and monocytic chemotaxis tests. The test was considered positive when an infiltration of at least 5 mm in diameter was shown after 48 hours (in the U.S. 80% of paediatric cases aged 2-10 years old were positive). A significant difference was noted in the average diameter of the infiltrations after the tetanic toxoid skin test in the two groups considered (P less than 0.001). The results appear to indicate that an adequate iodine intake is necessary for normal retarded immune response. The molecular mechanism by which iodine increases immune response is still to be decided.

[Physical health and drug dependence]. / Integrità fisica e tossicodipendenza.

90 hospitalized drug addicts observed in 1979-83 were examined. The investigation of the main anamnestic, clinical and instrumental parameters made it possible to construct a profile of the main physical handicaps affecting drug addicts and the main pathologies they encounter. In conclusion it is emphasised that it is probably not the drug in itself but rather their unhealthy life style that is the primary cause of drug addicts' poor health.