The hesitancy in the nutritional prevention

Abstract

Our letter discusses the concept of 'Nutritional Prevention Hesitancy', comparing it to the well-studied phenomenon of 'Vaccine Hesitancy'. Both hesitancies can be fueled by 'infodemics', the rapid spread of accurate and inaccurate information that can lead to public confusion and mistrust in authoritative sources. Drawing parallels between the two, the text highlights that nutritional prevention hesitancy can result in individuals not adopting evidence-based nutritional strategies, potentially leading to poorer health outcomes. The text emphasizes the critical role of diet in preventing diseases such as heart disease, diabetes, and certain types of cancer, and underscores the need for multifaceted strategies to combat misinformation and promote healthier dietary habits.

The "Nutritional Prevention" within Italy's National Prevention Plan 2020-25

Abstract

Italy's National Prevention Plan 2020-25 is the first to address nutritional prevention, highlighting its importance in combating chronic diseases. This letter discusses the relationship between food safety, nutritional security, and the need for nutritional prevention in the plan. Chronic diseases, such as cardiovascular disease, cancer, and diabetes, are significant public health concerns in Italy, with poor nutrition being a critical risk factor. Incorporating nutritional prevention can promote healthy eating habits, food security and sustainability, reduce healthcare costs, and promote social cohesion and equality. Successful implementation will require cooperation among the government, the private sector, and the civil society to ensure healthier food choices and prevent chronic diseases in Italy.

Neurosteroid pathway derangement in asphyctic infants treated with hypothermia: an untargeted metabolomic approach

BACKGROUND

The pathobiological mechanisms associated with perinatal asphyxia and hypoxic-ischemic encephalopathy are complex and poorly understood. The metabolic effects of therapeutic hypothermia have been partially explored.

METHODS

We conducted a single-center longitudinal study to investigate the metabolic effects of perinatal asphyxia and hypoxic-ischemic encephalopathy on the urinary metabolome of a group of 12 asphyctic infants over time compared to 22 matched healthy newborns, using untargeted metabolomics based on mass spectrometry.

FINDINGS

Over-representation pathway analysis identified the steroidogenesis pathway as being significantly disrupted, with reduced steroid levels in the first three days of life despite treatment with hypothermia. Comparison with matched healthy newborns showed that the urinary steroid content was lower in asphyctic infants before hypothermia. The lysine degradation and carnitine synthesis pathways were also significantly affected.

INTERPRETATION

Steroidogenesis is significantly disrupted in asphyctic infants compared to healthy newborns. Given how neurosteroids are involved in neuromodulation and neuroprotection, translational research is warranted on the potential role of neurosteroid-based intervention in asphyctic infants.

FUNDING

None.

Early Biomarkers of Bronchopulmonary Dysplasia: A Quick Look to the State of the Art

Bronchopulmonary dysplasia (BPD) is one of the most common pulmonary sequelae of extreme preterm birth, with long-lasting respiratory symptoms and reduced lung function. A reliable predictive tool of BPD development is urgent and its search remains one of the major challenges for neonatologists approaching the upcoming arrival of possible new preventive therapies. Biomarkers, identifying an ongoing pathogenetic pathway, could allow both the selection of preterm infants with an evolving disease and potentially the therapeutic targets of the indicted pathogenesis. The "omic" sciences represent well-known promising tools for this objective. In this review, we resume the current laboratoristic, metabolomic, proteomic, and microbiomic evidence in the prediction of BPD. KEY POINTS: · The early prediction of BPD development would allow the targeted implementation of new preventive therapies.. · BPD is a multifactorial disease consequently it is unlikely to find a single disease biomarker.. · "Omic" sciences offer a promising insight in BPD pathogenesis and its development's fingerprints..

Urinary metabotypes of newborns with perinatal asphyxia undergoing therapeutic hypothermia

Perinatal asphyxia (PA) still occurs in about three to five per 1,000 deliveries in developed countries; 20% of these infants show hypoxic-ischemic encephalopathy (HIE) on brain magnetic resonance imaging (MRI). The aim of our study was to apply metabolomic analysis to newborns undergoing therapeutic hypothermia (TH) after PA to identify a distinct metabotype associated with the development of HIE on brain MRI. We enrolled 53 infants born at >35 weeks of gestation with PA: 21 of them showed HIE on brain MRI (the “HIE” group), and 32 did not (the “no HIE” group). Urine samples were collected at 24, 48 and 72 hours of TH. Metabolomic data were acquired using high-resolution mass spectrometry and analyzed with univariate and multivariate methods. Considering the first urines collected during TH, untargeted analysis found 111 relevant predictors capable of discriminating between the two groups. Of 35 metabolites showing independent discriminatory power, four have been well characterized: L-alanine, Creatine, L-3-methylhistidine, and L-lysine. The first three relate to cellular energy metabolism; their involvement suggests a multimodal derangement of cellular energy metabolism during PA/HIE. In addition, seven other metabolites with a lower annotation level (proline betaine, L-prolyl-L-phenylalanine, 2-methyl-dodecanedioic acid, S-(2-methylpropionyl)-dihydrolipoamide-E, 2,6 dimethylheptanoyl carnitine, Octanoylglucuronide, 19-hydroxyandrost-4-ene-3,17-dione) showed biological consistency with the clinical picture of PA. Moreover, 4 annotated metabolites (L-lysine, L-3-methylhistidine, 2-methyl-dodecanedioic acid, S-(2-methylpropionyl)-dihydrolipoamide-E) retained a significant difference between the “HIE” and “no HIE” groups during all the TH treatment. Our analysis identified a distinct urinary metabotype associated with pathological findings on MRI, and discovered 2 putative markers (L-lysine, L-3-methylhistidine) which may be useful for identifying neonates at risk of developing HIE after PA.

Surgical management of large scalp infantile hemangioma in 30-month-old infant

Infantile Hemangiomas (IH) are the most common benign tumor of infancy, occurring in over 10% of newborns. The head and neck is the most frequently affected area (60%), and the scalp is a typical site for such large lesions. Scalp-IHs are usually focal lesions that can be both disfiguring and may lead to complications such as ulceration and bleeding. We describe a case of a 30-months old female who presented a large scalp-IH at birth that rapidly grew in the first year of life. Topical and systemic treatments (with timolol ointment and oral propranolol, respectively) were not effective in reducing dimensions of the hemangioma. After vascular imaging study, the patient underwent surgical resection of the IH and primary closure with excellent cosmetic outcome. When medical therapy is ineffective or cosmetic and functional integrity is threatened, early surgery allows to completely removing large scalp-IHs, with good cosmetic results.

Trends in respiratory management of transferred very preterm infants in the last two decades

BACKGROUND

Among infants needing urgent transfer after birth, very preterm infants are a high-risk sub-group requiring special attention. This study aimed to assess trends in early respiratory management in a large series of very preterm infants undergoing postnatal transfer.

METHODS

Trends in patient characteristics and early respiratory management were assessed in 798 very preterm infants who were transferred by the Eastern Veneto Neonatal Emergency Transport Service in 2000-2019. Trends were analyzed using joinpoint regression analysis and summarized as annual percentage changes (APCs).

RESULTS

Proportion of neonates with birth weight less than 1 kg decreased from 33% to 16% (APC -3.82%). Use of nasal-continuous-positive-airway pressure increased (at call: APC 15.39%; during transfer: APC 15.60%), while use of self-inflating bag (at call: APC -12.09%), oxygen therapy (at call: APC -13.00%; during transfer: APC -23.77%) and mechanical ventilation (at call: APC -2.71%; during transfer: APC -2.99%) decreased. Use of oxygen concentrations at 21% increased (at call: APC 6.26%; during transfer: APC 7.14%), while oxygen concentrations above 40% decreased (at call: APC -5.73%; at transfer APC -8.89%). Surfactant administration at call increased (APC 3%-10%), while surfactant administration when arriving at referring hospital remained around 7-11% (APC 2.55%).

CONCLUSION

Relevant trends toward "gentle" approaches in early respiratory management of very preterm infants undergoing postnatal transfer occurred during the last twenty years. In addition, the proportion of transferred extremely low birth weight infants halved. Clinicians and stakeholders should consider such information when allocating assets to both hospitals and transfer services and planning regional perinatal programs.

Longer aftershocks duration in extensional tectonic settings

Aftershocks number decay through time, depending on several parameters peculiar to each seismogenic regions, including mainshock magnitude, crustal rheology, and stress changes along the fault. However, the exact role of these parameters in controlling the duration of the aftershock sequence is still unknown. Here, using two methodologies, we show that the tectonic setting primarily controls the duration of aftershocks. On average and for a given mainshock magnitude (1) aftershock sequences are longer and (2) the number of earthquakes is greater in extensional tectonic settings than in contractional ones. We interpret this difference as related to the different type of energy dissipated during earthquakes. In detail, (1) a joint effect of gravitational forces and pure elastic stress release governs extensional earthquakes, whereas (2) pure elastic stress release controls contractional earthquakes. Accordingly, normal faults operate in favour of gravity, preserving inertia for a longer period and seismicity lasts until gravitational equilibrium is reached. Vice versa, thrusts act against gravity, exhaust their inertia faster and the elastic energy dissipation is buffered by the gravitational force. Hence, for seismic sequences of comparable magnitude and rheological parameters, aftershocks last longer in extensional settings because gravity favours the collapse of the hangingwall volumes.

Tissue Doppler Imaging in the evaluation of abdominal aortic pulsatility: a useful tool for the neonatologist

Sonographic cardiac evaluation of newborns with suspected aortic coarctation (AoC) should tend to demonstrate a good phasic and pulsatile flow and the absence of pressure gradient along a normally conformed aortic arch from the modified left parasternal and suprasternal echocardiographic views; these findings, however, may not necessarily rule out a more distal coarctation in the descending aorta. For this reason, the sonographic exam of newborns with suspected AoC should always include a Doppler evaluation of abdominal aortic blood flow from the subcostal view. Occasionally, however, a clearly pulsatile Doppler flow trace in abdominal aorta may be difficult to obtain due to the bad insonation angle existing between the probe and the vessel. In such suboptimal ultrasonic alignment situation, the use of Tissue Doppler Imaging instead of classic Doppler flow imaging may reveal a preserved aortic pulsatility by sampling the aortic wall motion induced by normal flow. We propose to take advantage of the TDI pattern as a surrogate of a normal pulsatile Doppler flow trace in abdominal aorta when the latter is difficult to obtain due to malalignment with the insonated vessel.

Intravenous paracetamol for PDA closure in the preterm: a single-center experience

Increasing recent evidence favors paracetamol use for patent ductus arteriosus (PDA) closure in preterms. Our study aims were (1) to assess efficacy and safety of intravenous (i.v.) paracetamol for PDA closure in a 23-32-week preterm population, as "first-line" (when traditional ibuprofen treatment was contraindicated) or "rescue" treatment (after ibuprofen failed), and (2) to identify predictors of PDA closure. The cumulative efficacy of consecutive cycles of i.v. paracetamol on PDA closure was confirmed after both "first-line" and "rescue" treatment, the overall PDA closure rates being, respectively, 56.7 and 61.1 % (p = 0.7624) after two cycles and 63.3 and 77.8 % (p = 0.2959) after three cycles. No toxicity was apparent after either "first-line" or "rescue" i.v. paracetamol treatment. On multivariate analysis, gestational age (GA) emerged as an independent predictor of PDA closure in the "first-line" i.v. paracetamol treatment group, while clinical risk index for babies (CRIB) score (a patient risk index based on birth weight, GA at birth, sex, patient's temperature on admission, and maximum base excess in first 12 h of life) was an independent predictor of PDA closure failure in the "rescue" group.

CONCLUSION

I.V. paracetamol proved effective in our study population. Randomized control trials (RCTs) are warranted to further investigate the efficacy and safety of i.v. paracetamol for PDA closure in preterms.

WHAT IS KNOWN

• Oral paracetamol has been judged as effective as oral ibuprofen for PDA closure in the preterm. • To date, only a handful of non-randomized studies exist to support the effectiveness of i.v. paracetamol in PDA closure. What is New: • Our observations confirm the clinical efficacy of i.v. paracetamol for PDA closure in a very low birth weight (VLBW)/extremely low birth weight (ELBW) preterm population. • Gestational age and CRIB score emerge as independent predictors of PDA closure.

Multi-district coronary tree involvement in a 17-year-old girl with Williams–Beuren syndrome

We describe a case of 17-year-old Chinese girl referred to our Pediatric Cardiology Unit for asthenia, reduced exercise tolerance, and dyspnea. Past medical history was relevant for multiple chest pain episodes in childhood and several syncopal episodes, for which the patient had been never evaluated. Clinical examination, electrocardiogram, and echocardiography were compatible with Williams–Beuren syndrome; such condition was later confirmed by genetic analysis. Cardiac magnetic resonance imaging showed transmural fibrosis of the apex with impaired left ventricular ejection fraction (29 %), severe stenosis of aortic sinotubular junction with left and right coronary ostia involvement; more importantly, the whole coronary artery tree beyond ostia was affected by multiple stenosis and aneurysmatic tracts. Ascending aorta proved hypoplastic, with post-stenotic dilation and multiple aneurysms. At the end of the diagnostic process, surgical risk was considered too high to proceed with the correction. The presented case is of educational value since it provides good iconographical illustration of diffuse, multiple-site coronary artery tree involvement, a rather rare co-morbidity in Williams–Beuren syndrome.

Subcutaneous fat necrosis of the newborn

Subcutaneous fat necrosis (SCFN) is a rare fat tissue inflammation of the newborn. Risk factors include cord prolapse, perinatal asphyxia, therapeutic hypothermia, meconium aspiration, and sepsis. When present, hypercalcemia comes with lethargy, hypotonia, irritability, vomiting, polyuria, polydipsia, constipation, and dehydration. Kidney injury must be avoided. SCFN is often completely autoresolutive.

Severe asymptomatic maternal antepartum hyponatremia leading to neonatal seizures: prevention is better than cure

Background

Pre-delivery maternal electrolyte derangements may reflect themselves in the newborn, since placental homeostasis determines electrolyte equilibrium between mother and fetus.

Case presentation

A term newborn, transferred to our Neonatal Intensive Care Unit 1 h after birth for an apnoea episode, presented with initially left-sided, and subsequently generalized tonic-clonic seizures due to severe hyponatremia (119 mmol/L). Seizures rapidly ceased after electrolyte correction plus a phenobarbital bolus. Deep hyponatremia was also detected in the mother (123 mmol/L).

Conclusions

As placental homeostasis determines electrolytes equilibrium between mother and fetus, obstetrics and neonatologists should be aware that any maternal dyselectrolytemia will reflect itself in the newborn; hence, it is fundamental to detect possible maternal electrolyte imbalances before delivery, in order to be prepared to timely correction of electrolyte derangements in the newborn.

Neonatal Hairy Ear Pinnae and Gestational Diabetes: Just a Coincidence?

A newborn girl of 36 weeks gestation was noted to have several anomalies, including bilateral low ear attachment with ear pinnae hypertrichosis, left preauricular pit, micrognathia, short lingual frenulum, and short neck. Pregnancy history revealed poorly controlled maternal gestational diabetes (GD). Localized hypertrichosis of the ear pinnae may represent a potential marker of GD and thereby alert physicians to suspect other potentially GD-associated conditions such as macrosomia, asphyxia, respiratory distress, hypoglycemia, hypocalcemia, hyperbilirubinemia, polycythemia, hypertrophic cardiomyopathy, and congenital anomalies, particularly those involving the central nervous system.

Congenital isolated Iso-Kikuchi syndrome in a newborn

Classic CO (also called Iso–Kikuchi syndrome) represents a benign, isolated condition associated with normal patient outcome. Nevertheless, clinical follow-up and/or further clinically-based tests are needed to exclude other nail diseases associated with multisystem pathology; complete family history is also important to determine sporadic or hereditary transmission of such condition.

Exstrophy-Epispadias Complex in a Newborn: Case Report and Review of the Literature

Aim The aim of this report is to present a brief review of the current literature on the management of EEC. Case Report A term male neonate presented at birth with classic bladder exstrophy, a variant of the exstrophy-epispadias complex (EEC). The defect was covered with sterile silicon gauzes and waterproof dressing; at 72 hours of life, primary closure without osteotomy of bladder, pelvis, and abdominal wall was successfully performed. Discussion EEC incidence is approximately 2.15 per 1,00,000 live births; several urological, musculocutaneous, spinal, orthopedic, gastrointestinal, and gynecological anomalies may be associated to EEC. Initial medical management includes use of occlusive dressings to prevent air contact and dehydration of the open bladder template. Umbilical catheters should not be positioned. Surgical repair stages include initial closure of the bladder and abdominal wall with or without osteotomy, followed by epispadias repair at 6 to 12 months, and bladder neck repair around 5 years of life. Those who fail to attain continence eventually undergo bladder augmentation and placement of a catheterizable conduit. Conclusion Modern-staged repair of EEC guarantees socially acceptable urinary continence in up to 80% of cases; sexual function can be an issue in the long term, but overall quality of life can be good.

Orange-brown chromonychia and Kawasaki disease: a possible novel association?

A 4-year-old girl with clinical and laboratory signs of Kawasaki disease (KD) was hospitalized and given intravenous immunoglobulin plus aspirin therapy, with rapid defervescence and clinical improvement, and was discharged 48 hours after admission. At the time of her follow-up echocardiography on day 14, orange-brown pigmentation of the nail beds was noticed and confirmed with dermoscopy. No clear association between KD and orange-brown chromonychia has been demonstrated, although reports and case series suggest a possible link between these two entities. We suggest that this particular finding might be encompassed in late (subacute) changes of extremities as part of KD diagnostic criteria.

Ankyloblepharon Filiforme Adnatum in a Newborn

Ankyloblepharon filiforme adnatum (AFA) is a rare congenital anomaly consisting of a partial or complete fusion of the eyelid margins. It is usually an isolated and benign malformation but its presence should alert the neonatologist because it can be rarely associated to other important multisystemic disorders. We report a case of a newborn presenting with isolated AFA at birth, treated in the first day of life.

Harlequin Color Change: Neonatal Case Series and Brief Literature Review

First clinical report of Harlequin color change (HCC) phenomenon came in 1952 from Neligan and Strang. Since then, HCC has been described in a fairly broad number of clinical reports involving neonates, infants, children, and adult patients. We here present a small case series of HCC occurring in neonates, pointing out three of the different possible presentations (hemifacial, patchy scattered across the whole body, and hemiscrotal) of this phenomenon. A brief discussion and literature review encompassing epidemiology, clinical features, physiopathology, associated conditions, and differential diagnoses of HCC is then presented. In most cases, HCC represents a benign, idiopathic, and rapidly autoresolutive phenomenon, with no need for treatment. Some drugs (especially anesthetics and prostaglandin E) are thought to enhance HCC expression through their influence on the capillary tone in the peripheral vascular bed; this effect is anyway promptly reversible with drug withdrawal. Only in rare circumstances, HCC may act as a clue for serious central nervous system disorders (e.g., meningitis; hypothalamic, brain stem, or sympathetic nervous system lesions); anyway, in these rare occurrences HCC always represents an epiphenomenon of the disease, never acting as the sole sign of the underlying disorder.

Infantile perineal protrusion in two monochorionic twins

Case Report Two female monochorionic-monoamniotic twins showed the same kind of infantile perineal protrusion (IPP) at birth. Lesions in both twins progressively healed until resolution in 6 weeks' time; none of the twins have manifested, till date, alvus disturbances. Discussion and Literature Review A literature review numbers approximately 100 reports of IPP. This condition has been classically classified into three categories: congenital/familiar (i.e., female sex, positive parental history of IPP), acquired (mainly due to constipation), and associated with lichen sclerosus et atrophicus. Conclusions and Final Remarks This case report describes, for the first time, the presence of IPP in monochorionic-monoamniotic twins, supporting the existence of hereditary/genetic factors in the developing of this condition.

Split median raphe: case series and brief literature review

We describe three cases of split median raphe of the penis (SMR) from our hospital newborn records from 2004 to 2013. One case was associated with median raphe cyst, one with skin hypochromia, and one with a scar-like aspect of the region of interest. SMR is thought to be the result of defective fusion of ectodermal tissue in the urethra and scrotum area or of defective growth of the perineal mesoderm around the urethra during gestation. Although SMR associated with other major penile congenital defects (epispadias, hypospadias, penile torsion, bifid scrotum, chordee) is common, isolated SMR is probably an underdiagnosed (although not rare) malformative condition. Recognizing SMR in a newborn may be of educational value to neonatologists because it leads to the search for and exclusion of the above-mentioned pathologic conditions.

Two-dimensional, M-mode and Doppler-derived echocardiographic parameters in sedated healthy growing female sheep

Despite the fact that sheep are a widely used animal model in cardiovascular research, reference values for transthoracic echocardiography in normal growing animals are not available. Eight healthy female lambs underwent two-dimensional, M-mode and pulsed wave Doppler echocardiographic examination at 100 days of age and every three months thereafter over a 12-month period. The study was conducted under sedation with midazolam, butorphanol and constant rate infusion of intravenous propofol. Their growth phase was completed at about one year of age. All the echocardiographic parameters considered were significantly correlated with body weight and age class except for the left ventricular systolic and diastolic diameters. Functional indices were not correlated to body weight or age except for the E-point to septal separation distance (EPSS). Doppler-derived parameters were not influenced by independent variables. Transthoracic echocardiography can be considered an applicable method for cardiovascular research using a growing lamb animal model after appropriate adjustments for age and body size.

Central administration of NPY or an NPY-Y5 selective agonist increase in vivo extracellular monoamine levels in mesocorticolimbic projecting areas

Selective NPY-Y5 antagonists are known to reduce NPY-evoked increase of food intake under free feeding conditions and drug-reinforced operant responding in rodents suggesting that NPY-Y5 receptors can regulate reinforcers, potentially by modulating the hypothalamic-limbic reward system. However, evidence published to date has revealed a limited expression of NPY-Y5 in the limbic areas. Thus, the first aim of the present study was to investigate the distribution of NPY-Y5 receptor binding sites in rat mesocorticolimbic projection areas such as the nucleus accumbens (NAc), medial prefrontal cortex (mPFC), and lateral hypothalamus (LH). Since mesocorticolimbic release of monoamines has been typically associated to the rewarding and motivational significance of reinforcers, we then compared the ability of NPY and an NPY-Y5 selective agonist, [cPP1-7,NPY19-23,Ala31,Aib32,Gln34]hPP, to evoke changes in extracellular monoamines from these brain regions using in vivo microdialysis techniques. Intracerebral doses of each compound were selected on the basis of those previously demonstrated to trigger food intake in a separate set of animals. We found that NPY-Y5 receptors were widely distributed in both the NAc and mPFC but not in the LH nuclei. Central administration of either NPY (4.5 nmol/rat) or the NPY-Y5 agonist (0.6 nmol/rat) induced a significant increase of dopamine (DA) output of up to 150% of basal values in the NAc. In addition, NPY induced a stepped increase of norepinephrine (NE) outflow in the NAc area. Also extracellular levels of NE levels were increased by both treatments in the mPFC (150% vs basal concentration). Hypothalamic monoamine levels were unaffected by both treatments. Extracellular serotonin (5-HT) levels were also unchanged in all regions. Given the NPY-Y5 agonist paralleled the in vivo ability of NPY to increase DA, these data suggest that the release of NPY may modulate behaviours associated to accumbal DA release such reward and reinforcement by, at least in part, acting on mesocorticolimbic NPY-Y5 receptors.

[Public food service in Milan city and Hinterland: GMP application (Part 1)]

Food service establishments are recognized as a critical sector concerning foodborne diseases occurrence, that is associated to contributing factors such as the anticipated preparation of meals that are often highly handled, and long-time distributed. A survey has been planned to evaluate the application of HACCP plan, in order to select a statistically representative sample of food services (restaurant, pizza-shop, bar, ..) in two Milan area' Public Health Units (PHU). During the inspections a proper check-list has been filled up in order to give a conformity evaluation about the global situation and about three specific sections: hygiene of food-handlers, procedures control, temperatures management. The food services have been found satisfactory in 9/106 and 5/54 cases in Milan City and in hinterland, respectively; among the two areas, highly significant differences have been revealed about temperatures management (68% and 28% unsatisfactory, respectively). In Milan City restaurants provided with HACCP plan scores are significantly different from unprovided restaurants scores (global and the three sections' evaluation); in Milan hinterland differences between provided and unprovided HACCP plan restaurants regard temperature management scores only. Useful suggestions to improve the quality of surveillance activity come from complex and heterogeneous findings shown in this study.

Activated astrocytes in areas of kainate-induced neuronal injury upregulate the expression of the metabotropic glutamate receptors 2/3 and 5

All forms of brain injury induce activation of astrocytes, although different types of injury induce different astrocytic responses. Activated astrocytes are characterised by hypertrophy, proliferation and increased expression of glial fibrillary acidic protein (GFAP). However, neither the process by which astrocytes become reactive nor the consequences are well understood. Recently, the application of specific growth factors to primary astrocytic cultures was shown to regulate dramatically the level of expression of the metabotropic glutamate receptors (mGluR) 5 and 3. In the present study, we have used an intracerebroventricular injection of a subconvulsive dose of kainic acid to produce a lesion of CA3a pyramidal neurones in the mouse hippocampus and to investigate whether mGluR expression was altered in reactive astrocytes in vivo. Immunohistochemical analysis showed strong mGluR5 and mGluR2/3 immunoreactivity in glial cells within the area of neuronal loss possessing the morphological feature of activated astrocytes. Double labelling with GFAP confirmed the expression of mGluRs by reactive astrocytes. The mechanical injury produced by the needle insertion in the cerebral cortex also produced enhanced expression of mGluR5 and mGluR2/3 in activated astrocytes proximal to the area of neuronal injury. Our finding of an increased mGluR expression in reactive astrocytes in vivo suggests that transcriptional regulation by specific growth factors on mGluRs is a phenomenon extendible to specific circumstances in vivo and not limited to in vitro models. Identification of the mechanisms of this adaptive plasticity will be central in the understanding of the events leading to neuronal survival and/or death.

Evidence against a permissive role of the metabotropic glutamate receptor 1 in acute excitotoxicity

Excitotoxicity has been proposed to contribute to neuronal loss in a broad spectrum of neurodegenerative conditions such as ischemia, hypoglycaemic coma or cerebral trauma. Excitotoxic neuronal injury appears to be mediated mainly by the over-activation of glutamate receptors, especially N-methyl-D-aspartate receptors, with subsequent excessive Ca2+ influx. Concurrent with the activation of glutamate-gated ion channels, metabotropic glutamate receptors (mGluR), which are G-protein coupled receptors, are also expected to be activated. Excessive stimulation of phospholipase C-coupled mGluR, mGluR1 and mGluRS, has been suggested to have neurotoxic consequences. However, the contribution of mGluR activation on excitotoxicity is still unclear and controversial. Here we report that, following ischemic and excitotoxic brain injuries, inactivation of mGluR1 does not prevent excitotoxic neuronal damage. Given the evidence that agonists at this group of mGluR promoted neuronal death in cerebrocortical cultures after oxygen-glucose deprivation or after N-methyl-D-aspartate exposure, our findings suggest that mGluR-mediated excitotoxicity is unlikely associated with mGluR1 but rather with other PLC-coupled mGluR.

Nicotine reinstatement of nicotine self-administration after long-term extinction

The effect of non-contingent priming injections of nicotine on the reinstatement of drug-seeking behaviour was studied in rats following the long-term extinction of nicotine self-administration. Male rats were trained to lever press for 0.03 mg/kg per infusion of intravenous nicotine. Nicotine maintained a robust self-administration behaviour (11.5 +/- 1.2; mean+/-SEM infusions/1-h session). When nicotine availability was discontinued, and only a non-contingent saline infusion was presented to the experimental subjects at the beginning of each daily session, responding for the drug-paired lever decreased to low values. After 4-13 sessions, responding extinguished. During this "extinction" period, non-contingent priming infusions of nicotine 0.001, 0.003, 0.01 or 0.03 mg/kg per infusion induced reinstatement of responding for the drug-paired lever. The increased responding, compared with the corresponding previous day on saline, was observed at all four nicotine doses but was not statistically significant for the higher priming dose (0.03 mg/kg per infusion). These preliminary results indicate that nicotine priming is able to induce reinstatement of drug-seeking behaviour in rats similarly to other reinforcing drugs. The present findings show analogies with similar phenomena described in ex-smokers and support the addictive role of nicotine in tobacco smoking.

Nicotine reinforcement in rats with histories of cocaine self-administration

Few reports have described conditions under which nicotine self-administration occurs in rats. In this study, rats which initially lever pressed for cocaine infusion (0.05 mg/kg) during 1 h experimental sessions continued to obtain similar infusion numbers when nicotine (0.03 mg/kg) was available. When saline was substituted for nicotine, infusions decreased from 11.8 +/- 4.5/h to 5.4 +/- 1.1/h but returned to pre-saline levels when it was reintroduced (12.0 +/- 5.4/h). These results indicate that nicotine can serve as a positive reinforcer for rats under the historical and schedule conditions described.

Resumption of ethanol-seeking behaviour in rats

Reexposure to alcohol may induce subjective craving and relapse to drug self-administration in ex-alcoholics. In this study, we proposed a rat model of "first-drink"-induced drug-seeking relapse. Responding was established in Long Evans rats under a fixed-ratio [FR5:S(1)] schedule for oral ethanol. Substitution of water for ethanol solution resulted in extinction of the self-administration. When responding for 8% ethanol and ethanol intake were stable for at least three consecutive 30min sessions, ethanol delivery was discontinued and only three water dipper cup presentations were available upon responding (3[FR5:water]). When the number of active lever presses decreased to a low stable level, responding was considered extinguished. In Experiment 1, subjects under "extinction" were challenged with three 8% ethanol dipper cup presentations. The re-exposure to ethanol was able to significantly reinstate responding in all subjects. Latency to complete the ethanol presentation significantly decreased compared to the value observed during the previous "extinction" session. In Experiment 2, other subjects were tested for extinction and then reexposed to 4, 8 or 16% ethanol. All three concentrations significantly increased active lever presses, but with different patterns of responding. The resumption of responding was linearly correlated to the ethanol concentration but no significant dose-effect relationship was found. In Experiment 3, reexposure to 8% ethanol in nondeprived rats induced a resumption of responding not significantly different from the effect observed in a restricted diet condition. These results demonstrate that ethanol reexposure is able to reinstate ethanol-seeking behaviour in rats with a past history of ethanol self-administration, and that this effect does not depend on a food motivation drive related to the calorific value of ethanol.