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Background: Renal functional reserve (RFR) measures the difference between the stimulated glomerular filtration rate (GFR) and the baseline GFR to detect early signs of renal functional decline. The protein load test (RFR-T) is the gold standard for RFR assessment but is a complicated procedure. Renal intraparenchymal resistance index (RRI) variation test (DRRI-T) is a non-invasive method to measure renal function reserve using ultrasound. A saline bag is used to induce renal vasodilation, and the DRRI is found by calculating the difference between baseline (without weight) and stress RRI (with weight). Normal DRRI-T is greater than 0.05. Methods: Our study compared RFR-T and DRRI-T in 50 patients with normal kidney function. We evaluated anthropometric parameters, cardiovascular risk factors, and performed blood and urine tests. Patients were over 18 years old with an estimated GFR (eGFR) CKD-EPI > 60 mL/min/1.73 m2. We excluded pregnant patients, those intolerant to milk protein, those with abnormal kidney ultrasound, or taking medication affecting intrarenal hemodynamics. We used Gwet's AC1 statistic to assess concordance between tests. Results: Our study found moderate concordance (0.545 coefficient value, p-value < 0.001) between preserved RFR-T (≥ 15 mL/min/1.73 m2) and DRRI (VN > 0.05). Preserved RFR had a significant association with baseline eGFR. Age and sex have an impact on RFR. RFR deteriorates with age, leading to a significant decrease (p= 0.0220), which is more pronounced in women than men (p = 0.0350). Conclusions: The Ultrasound test (DRRI-T) can measure RFR in just 10 min. This contrasts the gold standard method for estimating RFR, which involves a protein load test, takes a long time to execute, and requires numerous blood and urine samples, making it challenging for large-scale use. While the DRRI-T demonstrated moderate concordance with the protein load test, it did not meet the criteria to be considered a new gold standard test. We posit that it could serve as a valuable initial screening test, warranting further exploration alongside the more elaborate protein load test. Our study suggests that there may be differences between men and women in RFR changes and with regard to age, warranting further investigation on larger populations through ad hoc studies. Our work is among the first to offer original real-life experience in this field. Graphical abstract:

Objective To evaluate the anatomical and functional macular results and rate of complications following surgical treatment of primary macular hole (MH) with autologous platelet rich plasma (a-PRP) use.Design retrospective, interventional, non-randomized case seriesPartecipants and methods A cohort of 9 consecutive patients from January 1, 2019 to August 31, 2021 who underwent vitrectomy with a-PRP use for primary MH were included. Anatomical results based on spectral domain- optical coherence tomography (SD-OCT) and visual acuity were analyzed.Results 10 pseudophakic eye of 9 patients were enrolled. Six patients were female and three patients were male. The mean age was 69.9 years ± 1.48. The baseline MH minimum diameter was 486.1 μm ± 37.1, and mean pre operative best-corrected visual acuity (BCVA) was 0.91 ± 0.03 logMAR (Snellen equivalent 20/160). Mean 1 month post operative BCVA was 0.81 ± 0.57 logMAR (Snellen equivalent 20/130; p= 1.000); mean 3 month post operative BCVA was 0.66 ± 0.04 logMAR (Snellen equivalent 20/90; p= 0.006); mean 6 month post operative BCVA was 0.6 ± 0.04 logMAR (Snellen equivalent 20/80; p< 0.001). In all eyes, 10/10 (100%), there was a complete MH closure at 6 months follow up: 5 eyes (50%) with a U-type closure pattern, 4 eyes (40%) with a V-type pattern and 1 eye (10%) with an irregular foveal contour closure at 6 month follow-up. No ocular and systemic complications were reported.Conclusion The a-PRP use is a successful and promising vitreoretinal surgical technique option for primary MH

Biologically naïve patients with inflammatory bowel disease treated with vedolizumab (VDZ) are largely underrepresented in real-world cohorts. A multi-centre, observational cohort study was performed on the effectiveness and safety of VDZ in biologically naïve subjects with Crohn’s disease (CD) and ulcerative colitis (UC). Data of consecutive biologically naïve patients with CD and UC treated with VDZ from July 2016 to December 2019 were extracted from the cohort of the Sicilian Network for Inflammatory Bowel Disease. A total of 172 consecutive patients (CD: N?=?88; UC: N?=?84; median age 66.0 years) were included, with a median follow-up of 58.8 weeks. After 14 weeks, a clinical response was reported in 68.2% of patients with CD and 67.9% of patients with UC treated with VDZ, including 45.5% patients in the CD group and 46.4% patients in the UC group who achieved steroid-free remission. After 52 weeks, a clinical response was reported in 77.4% of CD and in 73.8% of UC patients treated with VDZ, including 59.7% patients in the CD group and 60.7% patients in the UC group who achieved steroid-free remission. This study demonstrates the effectiveness and safety of VDZ as a first-line biological, particularly among elderly patients.

Background Biologically naïve patients with inflammatory bowel disease treated with vedolizumab (VDZ) are largely underrepresented in real-world cohorts. A multi-centre, observational cohort study was performed on the effectiveness and safety of VDZ in biologically naïve subjects with Crohn’s disease (CD) and ulcerative colitis (UC).Methods Data of consecutive biologically naïve patients with CD and UC treated with VDZ from July 2016 to December 2019 were extracted from the cohort of the Sicilian Network for Inflammatory Bowel Disease.Results A total of 172 consecutive patients (CD: N= 88; UC: N= 84; median age 66.0 years) were included, with a median follow-up of 58.8 weeks. After 14 weeks, a clinical response was reported in 68.2% of patients with CD and 67.9% of patients with UC treated with VDZ, including 45.5% patients in the CD group and 46.4% patients in the UC group who achieved steroid-free remission. After 52 weeks, a clinical response was reported in 77.4% of CD and in 73.8% of UC patients treated with VDZ, including 59.7% patients in the CD group and 60.7% patients in the UC group who achieved steroid-free remission.Conclusions This study demonstrates the effectiveness and safety of VDZ as a first-line biological, particularly among elderly patients.

Myocarditis is an inflammatory disease of cardiac muscle with a variable clinical presentation, ranging from asymptomatic cases to different degrees of left ventricular systolic dysfunction up to heart failure and dilated heart disease. Ventricular arrhythmias (VA) can occur in patients with myocarditis and implantable cardioverter defibrillator (ICD) may be indicated in patients with life–threatening VA who are not in the acute phase of myocarditis and who are receiving optimal medical therapy. Reduced left ventricular ejection fraction (LVEF) below 35%, which is used as the main criterion for stratifying the risk of sudden cardiac death (SCD), has low sensitivity and low specificity for arrhythmic risk stratification in patients with myocarditis. Myocardial scar is the main determinant for VA in these patients. Cardiac magnetic resonance imaging (CMR), using late gadolinium enhancement(LGE), has an excellent ability to determinate the extension and characterization of myocardial scar, indeed CMR can potentially improve SCD risk stratification and indication for ICD implantation in patients with myocarditis. We present a case of a 36 years–old male presenting to the Emergency Department with a monomorphic sustained ventricular tachycardia in whom MRI revealed myocardial–pericardial recurrent inflammatory involvement and worsening disease progression. ICD was implanted in consideration of the high risk of life–threatening arrhythmias.

Systemic amyloidosis is a multisystem disorder caused by the misfolding, aggregation, and deposition of certain proteins in various organs and tissues. Cardiac involvement is common and worsens the prognosis. Atrial fibrillation is the most frequent arrhythmia in cardiac amiloidosis (CA), but many cases of ventricular arrhythmias (VA) and sudden cardiac death (SCD) have been described. We present a case of a 64–year–old man admitted following exertional syncope occurred after climbing a flight of stairs. His medical history included left gonarthrosis and surgery for right carpal tunnel syndrome one year before. Physical examination did not revealed signs of heart failure. A 12–lead electrocardiogram (ECG) showed a pseudoinfarction pattern with QS waves in V2 and V3 leads and low voltage in all limb leads. Routine blood tests revealed NT–pro–BNP 3436 pg/ml(n.v.0–125) and high–sensitive troponin T 67 pg/ml(n.v.< 58). A trans–thoracic echocardiogram showed left ventricle (LV) concentric thickening wall with granular and sparkling pat[1]tern, mild reduced ejection fraction, reduced global longitudinal strain with apical sparing, grade 3 diastolic disfunction, biatrial enlargement, mild mitral regurgitation, right ventricle free wall thickening (8 mm), mild reduced TAPSE, and mild pericardial effusion. Cardiac magnetic resonance (CMR) confirmed ventricular wall thickening with evidence at T1 mapping of interstitial infiltration more evident in the septum and inferior–lateral wall with apical savings. A total body 99mTc–HDP scintigraphy showed cardiac uptake with intensity similar to bone signal (Perugini Score 2) suggesting ATTR cardiac amyloidosis. Both kappa and lambda concentrations were normal. The genetic testing did not reveled mutations in the TTR gene. We concluded for a diagnosis of ATTR wild–type CA. The Holter ECG monitoring registered numerous ventricular ectopic beats and an episode of non–sustained ventricular tachycardia. A coronary angiography ruled out coronary artery disease. In consideration of the clinical–instrumental picture an ICD was implanted.

In this paper, the annual performance loss rates (PLRs) of five different grid-connected photovoltaic (PV) technologies based on outdoor field measurements were computed. The data used were collected in five different geographical locations covering five climatic zones. The PLR values were determined as absolute and relative measures for all sites and module types using seasonal time series decomposition using local regression. The results are very consistent and show a clustering of the PLR for each technology, provided some explainable outliers are removed. This allows the conclusion that in presence of properly sized and quality-driven systems, the influence of different climates on the degradation of PV modules is not very strong. In the first approximation, individual degradations rate values computed in a single climatic zone can be seen as representative for the technology in general. The reason for this is that for defects there is an associated activation energy, which has not been reached yet in the systems analyzed in this study.

With the large increase of installed photovoltaic (PV) capacity introduced in the energy system, one aspect that becomes increasingly important is the long-term reliability of the energy output and, thus, the estimation of the performance loss rate (PLR) for the different technologies on the market. Reliable performance metrics and statistical methods are needed to exploit continuous outdoor measurements, in order to assess the long-term performance and, thus, the financial viability of solar PV systems, as well as their long-term stability as an important part of the energy mix. This paper presents and compares seven different methodologies to extract reliable long-term performance indicators from monitored field data. The methods can be grouped into four different approaches. First, a simple computation of the performance ratio (PR) is used as a benchmark for the other methods. Second, these PR values are fitted to two sinusoidal functions that emulate the climatic influence and a decaying trend that represents the degradation of the PV array. Third, two kinds of time-series decomposition [namely classical series decomposition and seasonal-trend decomposition based on local regression (STL)] are applied, and the trend is linearized to find the PLR. Finally, two methods are presented that aim to utilize the physical properties of the material to correct for seasonal fluctuations, namely the correction to standard test conditions of the PR via normal operating conditions (PRNOCT) and a performance metric called array photovoltaic for utility system applications (PVUSA). In this work, the degradation rates from the different computational methods are presented. The main focus is on the understanding of the uncertainty associated with each of the methods. All the methods yield comparable results; however, the statistical time-series methods deliver the highest accuracy in almost all the investigated cases, especially for technologies affected by metastable effects. On average, the two periodic methods halve the uncertainty and the time-series methods reduce the uncertainty, on average, to 45%, whereas the methods PRNOCT and PVUSA reduce to only 75% of the benchmark method. Methods that are trying to incorporate the module physics (PRNOCT and PVUSA) work best to reduce the uncertainty only for technologies, in which the temperature behavior is well known, i.e., crystalline-silicon-based modules. For this reason, the usage of the STL method for the computation of the PLR is proposed.

The caseous calcification of the mitral annulus (CCMA) is a rare degenerative condition of the mitral valve (0.067% prevalence in the general population) that generally affects older women with hypertension, chronic kidney disease and dyslipidemia. Usually CCMA is asymptomatic and it is associated with mild to moderate mitral regurgitation and it can cause severe mitral valve dysfunction that requires surgical treatment. CASE 1: A 84–year–old woman, with arterial hypertension, was evaluated in our clinic to perform a transthoracic echocardiogram (TTE) for a previous finding of heart murmur. TTE reveled at the level of the posterior mitral annulus a hyperechoic roundish formation with a central eco–shiny area with a maximum diameter of 20x20 mm. A tridimensional trans–esophageal echocardiography (3D TEE) allowed a better characterization of the mass showing well–defined contours, adhered to the posterior mitral annulus, systolic dislocation of the anterior mitral leaflet, with slight mitral regurgitation. Considering the morphological characteristics of the mass we concluded for a presumptive diagnosis of CMAC. We recommended regular follow–up to the patient. After 6 and 12 months the mass did not change in size and echostructure. CASE 2: An 88–year–old woman with chronic kidney disease, high blood pressure and chronic ischemic heart disease was admitted to our ward for acute heart failure. TTE showed a large an echodense mass (43 × 19 mm) involving the posterior mitral annulus, with a central echo–lucent area. A 3D TEE was performed with better mass characterization: involvement of the entire posterior mitral ring, reduced movement of the posterior mitral flap, anterior mitral flap with normal morphology and normal mobility. In consideration of the echocardiographic characteristics we concluded for the presence of CMAC. We discharged the patient with indication for a regular clinical and echocardiographic follow–up.

Infections with endocardial vegetation or the exuberant growth of neoendothelialization tissue (cloth –tissue overgrowth) in heart valve prostheses lead, among other complications, to the malfunction of the prostheses themselves due to obstruction. Among the diagnostic methods available to us, to achieve the diagnosis of prosthetic dysfunction, in recent years three–dimensional transesophageal echocardiography (3D TTE) has become increasingly imposed. We present two clinical cases of patients admitted to our Cardiology department Case 1: Patient of 62 years old, hospitalized for established congestive heart failure. In 2006 he underwent ascending aorta replacement with Dacron 28 prosthesis and aortic valve replacement with mechanical prosthesis (Sorin 25) for aortic bicuspid and ascending aortic aneurysm. During the last follow–up was observed a slight increase in the value of intraprosthetic gradients, as well as a variability in INR values. Physical examination showed signs of heart failure (NT–ProBNP >1000 pg/ml); normal inflammation indices (PCR <2.9 mg/l); ECG: sinus rhythm at 85 bpm with left ventricular overload; trans–thoracic echocardiography showed severe intraprosthetic aortic gradient (Gmax 132mmHg–Gmed 72mmHg), doubtful for cloth adhered to prosthetic discs; 3D TTE shoved hyperechoreflective image adhered to the posterior mobile element (5x9mm) which was fixed in semi–closure. Subsequently, the patient underwent prosthetic replacement surgery with biological prosthesis. Case 2: Patient of 67 years old, heavy smoker, hypertensive, with aortic mechanical prosthesis, a few weeks before hospitalized for Corynebacterium Jeikeium infection. Hospitalized again for fever with increased inflammation indices (CRP 202mg/l). A first TTE concluded for suspected endocarditis of the prosthesis; this doubt was also dissolved by 3D TTE which showed a soft protruding image of the posterior mobile element, preventing the opening and determining severe stenosis (Gmax 160mmHg–Gmed of 80 mmHg), so this patients was transferred to the cardiac surgery department.

Acetylcholine, acting on both nicotinic receptors (nAChRs) and muscarinic receptors (mAChRs), plays a role in the regulation of synaptic plasticity, being involved in the regulation of cellular processes and cognitive functions, such as learning, memory and attention. Recently, G protein coupled receptors (GPCRs), including mAChRs, have been reported to transactivate tyrosine-kinase receptors (RTK), such as epidermal growth factor receptor (EGFR), and initiate their intracellular signaling. In this minireview we have first analysed the RTK transactivation mechanisms, involving cholinergic receptors, and thereafter the interplay between AChR and neurotrophic factor systems built up by FGF2 and fibroblast growth factor receptor 1 (FGFR1). Although mAChR and FGFR1 activate common signaling pathways, playing similar roles in the regulation of central nervous system (CNS) plasticity and trophism, this analysis revealed that at the present there are no data reporting an involvement of cholinergic receptors in the FGFR1 transactivation. However, here we reported preliminary results on FGFR1 transactivation by mAChRs, suggesting a possible interaction between mAChR and neurotrophic factor receptors, with potential relevance for cognitive functions.

At the 17thnational meeting of the “Peritoneal dialysis” Study Group (Italian Society of Nephrology), held in Montecatini Terme (20–22 March, 2014), 141 physicians received a questionnaire to survey the opinion of the Italian Nephrologists on the issue of physical activity in peritoneal dialysis patients.All participants agreed on the benefits of physical activity and on the need for its implementation in dialysis patients. Overall, 90% of the participants considered physical activity as an important aspect of the clinical care management. Most of the Nephrologists (61%) believed that patients are interested in exercising and that they can improve their physical activity if motivated or stimulated by the dialysis staff. However, some warnings (by 85% of the physicians) emerged about the safety of physical activity in dialysis patients. Despite this, many Nephrologists believed they could be able to prescribe exercises to their patients. About 86% of the participants declared to give advices about physical activity, but only few of them (7%) provided written informative material or worked together with professionals in the field of physical activity care.In conclusion, the survey revealed that participants strongly believe that a sedentary lifestyle is deleterious and that physical activity should be implemented in peritoneal dialysis patients. However, this implementation seems to be rather difficult in real life. Therefore, it is highly desirable to create a scientific cooperation among specialists and health professionals of different fields to improve the physical activity and exercise programs of peritoneal dialysis patients.

C-type natriuretic peptide (CNP) possesses well-established cardiovascular properties. Although present in the mammalian kidney, CNP production in human kidney and its modulation in human renal disease remain less defined. We investigated the presence of CNP in normal human kidney and in patients with nephrotic syndrome (NS). We also addressed whether or not a low-protein diet (LPD) alters plasma CNP and urinary CNP excretion in NS. In situ hybridization studies demonstrated CNP mRNA expression in tubular cells and glomeruli of normal human kidneys. CNP immunoreactivity was positive in proximal, distal, and medullary collecting duct tubular cells in both controls and patients with NS. The ratios of plasma CNP and urinary CNP to creatinine were significantly higher in patients with NS compared with controls. Urinary CNP, but not plasma CNP, was significantly lowered in patients with NS after an LPD. Similarly, the ratios of urinary protein to creatinine and urinary albumin to creatinine, but not urinary guanosine 3′,5′-cyclic monophosphate to creatinine, decreased significantly with an LPD. These data confirm and extend previous reports and demonstrate for the first time the presence of CNP in human kidney with NS. We also report increased plasma CNP concentration and urinary CNP excretion in NS patients and a significant reduction of CNP excretion with an LPD. Our findings demonstrate that CNP metabolism is altered in patients with NS and support the hypothesis that activation of renal CNP can be partially offset by an LPD. These results underscore that the beneficial effect of an LPD on protein excretion is paralleled by a substantial reduction in intrarenal CNP release.

To determine levels of natriuretic peptides (NPs) in patients with end-stage renal disease (ESRD) and to examine the relationship of these cardiovascular pep-tides to left ventricular hypertrophy (LVH) and to cardiac mortality.

Neurotrophin-4 (NT-4) is produced by slow muscle fibers in an activity-dependent manner and promotes growth and remodeling of adult motorneuron innervation. However, both muscle fibers and motor neurons express NT-4 receptors, suggesting bidirectional NT-4 signaling at the neuromuscular junction. Mice lacking NT-4 displayed enlarged and fragmented neuromuscular junctions with disassembled postsynaptic acetylcholine receptor (AChR) clusters, reduced AChR binding, and acetylcholinesterase activity. Electromyographic responses, posttetanic potentiation, and action potential amplitude were also significantly reduced in muscle fibers from NT-4 knock-out mice. Slow-twitch soleus muscles from these mice fatigued twice as rapidly as those from wild-type mice during repeated tetanic stimulation. Thus, muscle-derived NT-4 is required for maintenance of postsynaptic AChR regions, normal muscular electrophysiological responses, and resistance to muscle fatigue. This neurotrophin may therefore be a key component of an activity-dependent feedback mechanism regulating maintenance of neuromuscular connections and muscular performance.

XIAP (X-chromosome-linked inhibitor of apoptosis protein) is an antiapoptotic protein which inhibits the activity of caspases and suppresses cell death. However, little is known about the presence and function of XIAP in the nervous system. Here we report that XIAP mRNA is expressed in developing and adult rat brain. Using a specific antibody, we observed XIAP-immunoreactive cells in different brain regions, among others, in the hippocampus and cerebral cortex. Kainic acid, which induces delayed cell death of specific neurons, increased the levels of XIAP in the CA3 region of hippocampus. XIAP was, however, largely absent in cells undergoing cell death, as shown by TUNEL labeling and staining for active caspase-3. In cultured hippocampal neurons, XIAP was initially upregulated by kainic acid and then degraded in a process blocked by the caspase-3 inhibitor DEVD. Similarly, recombinant XIAP is cleaved by active caspase-3 in vitro.The results show that there is biphasic regulation of XIAP in the hippocampus following kainic acid and that XIAP becomes a target for caspase-3 activated during cell death in the hippocampus. The degradation of XIAP by kainic acid contributes to neuronal cell death observed in vulnerable neurons of the hippocampus after caspase activation.

By combining in silico and bench molecular biology methods we have identified a novel human gap junction gene that encodes a protein designated HCx31.9. We have determined its human chromosomal location and gene structure, and we have identified a putative mouse ortholog, mCx30.2. We have observed the presence of HCx31.9 in human cerebral cortex, liver, heart, spleen, lung, and kidney and the presence of mCx30.2 in mouse cerebral cortex, liver and lung. Moreover, preliminary data on the electrophysiological properties of HCx31.9 have been obtained by functional expression in paired Xenopus oocytes and in transfected N2A cells.

THE present experiments were designed to extend previous work showing that acute intermittent (-)nicotine treatment upregulates the level of fibroblast growth factor-2 (FGF2) mRNA in several rat brain regions, by the use of the nicotinic acetylcholine receptor (nAChR) agonist ABT-594 with preferential selectivity for the α4β2 nAChR subtype. ABT594 treatment led to a well-defined temporal and regional up-regulation of FGF-2 mRNA. A double labelling analysis showed that the up-regulation of FGF-2 mRNA involves both neuronal and non-neuronal cells. The effects of ABT-594 on FGF-2 expression were antagonized by the preferential α4β2 antagonist dihydro-βerythroidine (DHβE), but not by α7 antagonist metyllycaconitine (MLA). In conclusion, FGF-2 mRNA levels can be increased in several brain regions upon α4β2 nAChR activation, suggesting a therapeutic significance in neurodegenerative disorders.

GFAPβ mRNA is an alternative transcript of the glial fibrillary acidic protein (GFAP) gene, whose transcriptional start site is located 169 nucleotides upstream to the classical GFAPα mRNA. By an RT-PCR method with primers on separate exons, we were able to confirm the presence of GFAP transcripts with a longer 5′ untraslated region in all the examined areas of rat brain and in primary cultures of astroglial cells. Northern blot analysis, using an oligoprobe specific for the 5′ region of GFAPβ, revealed a single hybridization band of 2.9 kb in all the brain regions examined and in primary cultures of astroglial cells. The availability of the quantitative Northern blot assay allowed further studies on the regulation of GFAPβ expression in vivo. Since it is well-known that neuronal brain injury is one of the most powerful inducers of GFAP, we examined the expression of GFAPα and β after a neurotoxic lesion in the rat hippocampus. Results obtained show a parallel increase in both GFAP transcripts with an identical time-course, suggesting that regulatory regions of the gene influence in similar way the rate of transcription at the two different start sites (α and β) or that a similar post-transcriptional mechanism is involved in regulating both mRNA isoforms.

Levels of mRNA for neurotrophins (brain-derived neurotrophic factor, BDNF; neurotrophin 3, NT-3; neurotrophin 4, NT-4) and their receptors (trkA, trkB, trkC) and for glial cell line-derived neurotrophic factor (GDNF) and its receptors (ret, GDNFR-) were measured in rat thyroid tissue by ribonuclease protection assays. In thyroid tissue the NT-3 mRNA level was threefold lower and the NT-4 mRNA level sixfold higher than those detected in adult rat hippocampus, while BDNF mRNA was undetectable. Very low levels of mRNA for truncated trkB and trkC receptors and no catalytic trkA, trkB or trkC were found. In conclusion NT-3 and NT-4, but not the corresponding functional receptors, are expressed in the thyroid tissue. Therefore, it is unlikely that these factors serve a direct local autocrine or paracrine function in thyroid cell types, and a target-derived mode of action on neurons innervating the thyroid tissue is suggested. An opposite result has been found for the neurotrophic factor GDNF: thyroid tissue showed a high level of transcripts for the GDNF receptor subunits (GDNFR- and Ret), while GDNF mRNA was undetectable. The in situ hybridization analysis of GDNFR- and ret mRNA revealed an interesting difference in the cell distribution of these transcripts: ret mRNA is selectively expressed in a subpopulation of cells scattered in the follicular epithelium and in the interfollicular spaces, while GDNFR- expression is more homogeneous and widespread, including the more abundant cell type of the thyroid gland: the follicular cell. Double-labeling in situ hybridization/immunocytochemistry experiments, with a specific marker (calcitonin), showed that parafollicular cells express ret but not GDNFR-. This differential distribution of the GDNF receptor components (GDNFR- and ret) may reflect a peculiar biological role in intercellular communication in the thyroid gland.

The neuronal control of murine natural suppressor (NS) cell activity was studied in mice following lesion of the arcuate nucleus of the hypothalamus performed by the postnatal treatment with monosodium glutamate (MSG). The suppressor activity was evaluated as the ability of spleen or bone marrow cells (suppressors) to suppress the mitogen-induced lymphocytes proliferation of allogeneic Balb/c spleen cells (indicators). The study was carried out on three different inbred strains of mice (C57BL/6, DBA/ 2 and CBA). The results demonstrated that, in all strains used, the treatment of mice (12 day-old) with MSG led to a marked reduction of natural suppressor cell activity. This reduction was observed in both spleen and bone marrow, the lymphoid organs in which the NS cell activity is usually present. A reduced NS activity was also present in the bone marrow of MSG-treated adult mice, suggesting a permanent alteration of NS cell activity. These results provide additional support on neuromodulation of immune system.

The presence of the neurotrophin, nerve growth factor, brain derived neurotrophic factor, neurotrophin-3 and neurotrophin-4 (NGF, BDNF, NT-3 and NT-4) and their receptors of the tyrosine kinase family (trkA, trkB and trkC) have been investigated in the choroid plexus and dura mater of the adult rat by ribonuclease protection assay. The choroid plexus contained high levels of mRNAs for NGF and NT-4, and low levels of NT-3 and BDNF mRNA; and high levels of trkB mRNA, and undetectable levels of trkA and trkC mRNA. In the dura mater there were high levels of NT-3 and NGF, and low levels of BDNF and NT-4 mRNAs; and high levels of trkC mRNA, and relatively high amount of trkB mRNA, while levels of trkA mRNA was undetectable. The present analysis revealed a different distribution of neurotrophins and their related receptors in the choroid plexus and dura mater.

In the present study we analysed, by in situ hybridization, the effects of an extremely localized mechanical brain injury, obtained by the simple needle insertion (30 g) in rat hippocampus or cortex, on the expression of several immediate early genes (c-fos, fosB, c-jun, junB, junD, zif/268). When the needle is deepened into the hippocampus through the cortex, a simultaneous ipsilateral activation of all examined IEGs is observed in both the cerebral cortex and in the dentate gyrus of hippocampus. Maximal effects are detected between 30 and 60 min with the following rank order of induction: zif/268 > c-fos > junB > fosB > c-jun > junD. On the other hand, when the penetration of the needle is limited to the cerebral cortex the activation of the IEGs (c-fos, fosB, junB and zif/268) spreads throughout the ipsilateral cortex but does not involve the hippocampal region. Systemic administration of ketamine, a non-competitive antagonist of N-methyl-d-aspartate (NMDA) receptors, blocks IEG expression induced by brain injury in the cerebral cortex and in the hippocampal dentate gyrus. Pretreatment with the anticonvulsant diazepam, the anaesthetic urethane, or the muscarinic receptor antagonist scopolamine do not affect the injury-induced genomic response. An important regional difference in the sensitivity to the blocking effect of ketamine can be observed analysing the results regarding the zif/268 gene expression in the hippocampus. A clear induction of this gene by needle insertion can be detected both in the dentate gyrus and in the hippocampal layers. However, the dentate gyrus induction is completely blocked by the ketamine pretreatment, while the induction in the hippocampal layers is not affected by this NMDA antagonist. The zif/268 induction in the hippocampal layers is not blocked even if the intracerebroventricular administration of a non-NMDA glutamate receptor antagonist is associated to the systemic pretreatment with ketamine. This result represents the first observation of injury-induced neuronal genomic responses that are not critically dependent on the NMDA receptor activity.

An increase in astrocyte mitogenic factors and in some specific astroglial enzymatic activities after neuronal injury has been observed. Our study is concerned with the effect of the intracerebral administration of ibotenic acid (IBO) into the rat hippocampus. IBO injection causes a selective degeneration of neurons while sparing afferent fibers. We observed a transient increase in glutamine synthetase activity, a well-known astroglial marker, reaching a peak at 9–15 days after injury in lesioned hippocampus. We investigated the presence of astrocyte mitogenic factors at various times after toxin injection. Crude extracts, prepared from lesioned hippocampi 4, 9, and 14 days after IBO injection, were tested for the ability to stimulate [methyl-3H]thymidine incorporation into rat astroglial cell cultures. Crude extracts prepared 9 and 14 days after IBO injection showed a higher mitogenic activity compared to extracts prepared 4 days after lesion. Mitogenic activity of injured brain extracts was suppressed by heat inactivation (100°C for 10 min).

Receptor serine-threonine kinases (RSTK) mediate inhibitory as well as stimulatory signals for growth and differentiation by binding to members of the transforming growth factor-beta (TGF-beta) superfamily. Over 12 different RSTKs have been isolated so far, displaying wide expression in peripheral tissues and in the nervous system. Here we report the isolation and characterization of a novel type I RSTK termed activin receptor-like kinase-7 (ALK-7) that, unlike other members of this receptor family, is predominantly expressed in the adult central nervous system. The ALK-7 gene encodes a 55-kDa cell-surface protein that exhibits up to 78% amino acid sequence identity in the kinase domain to previously isolated type I receptors for TGF-beta and activin. In the extracellular domain, however, ALK-7 is more divergent, displaying comparable similarities with all members of the ALK subfamily. RNase protection and in situ hybridization studies demonstrated a highly specific mRNA distribution restricted to neurons in several regions of the adult rat central nervous system, including cerebellum, hippocampus, and nuclei of the brainstem. Receptor reconstitution and cross-linking experiments indicated that ALK-7 can form complexes with type II RSTKs for TGF-beta and activin in a ligand-dependent manner, although direct binding of ALK-7 to ligand in these complexes could not be demonstrated. The specific expression pattern of ALK-7, restricted to the postnatal central nervous system, indicates that this receptor may play an important role in the maturation and maintenance of several neuronal subpopulations.

Glial cell line-derived neurotrophic factor (GDNF) mediates neuronal survival through a receptor complex composed of the c-Retproto-oncogene and GFRα-1, a member of a family of GPI-anchored receptors. The extent of cross-talk between GDNF and GFRα receptors and its possible significance for c-Ret activation is presently unclear. Using chemical crosslinking we demonstrate here a specific interaction between GDNF and GFRα-2 expressed in COS cells, albeit of a lower affinity than the one between GDNF and GFRα-1. In addition, GFRα-2 mediated crosslinking of GDNF to c-Ret as well as ligand-dependent stimulation of c-Ret tyrosine phosphorylation. We also describe the isolation of a novel, more divergent member of the GFRα family, GFRα-3, which did not bind GDNF directly, but was able to mediate crosslinking of GDNF to c-Ret when both receptors were coexpressed in COS cells. Thus, all three GFRα receptors mediate GDNF binding to c-Ret with efficiencies GFRα-1>GFRα-2 >GFRα-3. c-Ret showed high levels of constitutive tyrosine autophosphorylation upon overexpression in COS cells, which was inhibited in a dose-dependent manner by coexpression with any of the GFRα receptors, suggesting that GFRαs may also provide a gain control mechanism to increase the signal-to-noise ratio of the response to ligand. GFRα-2 showed a dynamic pattern of expression in rat brain, distinct from that of GFRα-1, characterized by high expression in cortex, basal forebrain, and specific layers of the olfactory bulb, and low or no expression in substantia nigra, cerebellum, and motor nuclei. GFRα-2, but not GFRα-3 mRNA expression was highly induced in several nuclei after stimulation with kainic acid. In contrast to GFRα-1 and GFRα-2, GFRα-3 expression in postnatal and adult brain was highly restricted. Developmentally regulated expression of GFRα-3 was, however, detected in several peripheral organs and ganglia. Together, these results indicate complementary roles for GFRα receptors in the regulation of c-Ret activity and the maintenance of distinct neuronal circuits in the central and peripheral nervous systems.

1-O-octadecyl-2-O-methoxy-rac-glicero-3-phosphocholine (ET-18-OCH3) is a synthetic derivate of 2-lysophosphatidylcholine, endowed with some immunomodulatory and anticancer effects. In the present work we report that a chronic (1 μg/g b.w. for 2 weeks) or acute single dose injection of ET-18-OCH3produced a recovery of thymus weight and thymocytes cellularity in two different strains of mice, C57BL6 and Swiss mice, undergoing thymus age-dependent involution. This effect was significant when the thymus weight was reduced at 50% and it was without effect on thymus lacking age dependent involution, such as young mice. The ability of ET-18-OCH3to produce thymus weight and thymocyte cellularity recovery was also demonstrated in adult mice showing hypotrophy of thymus induced by chronic corticosterone treatment, suggesting that this compound could be effective against thymus hypotrophy induced by external stimuli. This thymotrophic effect of ET-18-OCH3was not dependent on direct action on thymocyte proliferation, but probably it was dependent on its action on thymic epithelial cells to produce hormone thymulin, which level was found significantly increased in the plasma. These results provide further immunomodulatory propriety of ET-18-OCH3and open the possibility to use this compound to counteract thymus hypotrophy.

Natural killer (NK) cells have an important role in non-adaptative resistance to tumours and their metastatic spread in vivo1–5. Maturation of NK cells and the intensity of their activity are affected by many endogenous and external factors, as well as by regulatory cells1. The possibility that some effects of the central nervous system on tumour resistance are mediated via NK activity has also been suggested6. Destruction of the tuberoinfundibular region of the hypothalamus in rodents led to a significant increase in tumour growth7–9. We show here that destruction of its ventromedial, dorsomedial and arcuate nuclei persistently abrogates NK activity in mice. By contrast, cortical lesion and operative stress depress it partially, and for a brief period only. Abrogation is the result of a block of NK lineage maturation, causing a severe decrease in the number of large granular lymphocytes (LGL), a lymphocyte population associated with NK activity10,11. Macrophage, B- and T-lymphocyte functions, however, are not significantly affected. Agents inducing NK-cell maturation or activation such as poly inosinic-polycytidylic acid (poly(I:C), interferon (IFN) and interleukin-2 (IL-2) restore NK activity, and normalize the number of LGL.

Receptor serine-threonine kinases (RSTK) mediate inhibitory as well as stimulatory signals for growth and differentiation by binding to members of the transforming growth factor-β (TGF-β) superfamily. Over 12 different RSTKs have been isolated so far, displaying wide expression in peripheral tissues and in the nervous system. Here we report the isolation and characterization of a novel type I RSTK termed activin receptor-like kinase-7 (ALK-7) that, unlike other members of this receptor family, is predominantly expressed in the adult central nervous system. The ALK-7 gene encodes a 55-kDa cell-surface protein that exhibits up to 78% amino acid sequence identity in the kinase domain to previously isolated type I receptors for TGF-β and activin. In the extracellular domain, however, ALK-7 is more divergent, displaying comparable similarities with all members of the ALK subfamily. RNase protection and in situhybridization studies demonstrated a highly specific mRNA distribution restricted to neurons in several regions of the adult rat central nervous system, including cerebellum, hippocampus, and nuclei of the brainstem. Receptor reconstitution and cross-linking experiments indicated that ALK-7 can form complexes with type II RSTKs for TGF-β and activin in a ligand-dependent manner, although direct binding of ALK-7 to ligand in these complexes could not be demonstrated. The specific expression pattern of ALK-7, restricted to the postnatal central nervous system, indicates that this receptor may play an important role in the maturation and maintenance of several neuronal subpopulations.

The present study provides a detailed comparative description in the adult rat brain of areas that express MRNAs coding for the fibroblast growth factor subtype receptors 1–3 (FGFR1–3). One observation in this analysis was a widespread expression in the brain of all three FGFR mRNAs, according to the following rank order: FGFR1, diencephalon < telencephalon < mesencephalon and metencephalon < myelencephalon; FGFR2 and FGFR3, telencephalon < diencephalon < mesencephalon and metencephalon < myelencephalon. Another observation was an apparent cellular specificity in their basal expression. Thus, the FGFR1 mRNA was expressed mainly in large and weakly stained cells, whereas FGFR2 transcripts were expressed primarily in small and strongly stained cells and in cells of brain regions devoid of neuronal cells, such as the white matter. FGFR3 mRNA was always detected in small and strongly stained cells with scattered distribution and was not expressed in the white matter. However, FGFR2 mRNA was weakly expressed also in large cells localized in some nuclei of the lower brainstem, in the diagonal band, and in the septum. Furthermore, in the medial habenula and in the nuclei of the pons, there exists a high density of cells expressing both FGFR1 and FGFR2 (60–100%). With neurotoxic lesions involving 6‐hydroxy‐dopamine microinjections in the substantia nigra, reactive glial cells in the lesioned area and surrounding the cannula tract showed an increase in the expression of both FGFR1 and FGFR2 mRNAs, whereas no increased expression was found for FGFR3 mRNA. Taken together, these findings showed that these three FGF receptors exist in all subtypes of cells of each brain region. Their apparent cellular specificity suggests that these receptor subtypes can have a differential trophic role in the brain, reflecting the various biological activities shown by the ligands of the FGF family. J. Comp. Neurol. 379:226–246, 1997. © 1997 Wiley‐Liss, Inc.

A negative correlation has been found between smoking and Parkinson's disease. There is evidence to suggest that this correlation appears to be associated with a neuroprotective role of nicotine for dopamine neurons at least in relation to mechanical injury. However, 1-methyl-4-phenyl-1,2,3,6,-tetrahydropyridine (MPTP) neurotoxicity to dopamine neurons is enhanced by chronic continuous (−)nicotine. More recently, basic fibroblast growth factor has been found to possess neurotrophic activities for many nerve cells including the dopamine cells in vivo and in vitro. Therefore, it is of interest to explore a possible effect of nicotine on basic fibroblast growth factor expression in the ventral midbrain of intact and 6-hydroxydopamine-lesioned rats and how treatment with nicotine can alter the 6-hydroxydopamine-induced injury of the nigral dopamine nerve cells as evaluated by dopamine biochemistry. In the present paper, an analysis of the effects of chronic continuous infusion of (−)nicotine via minipumps was carried out on basic fibroblast growth factor expression in the vental midbrain of the intact male rat and of the 6-hydroxydopamine lesioned rat. A quantitative messenger RNA protection assay analysis was used as well as an immunocytochemical analysis in the substantia nigra. Our findings give evidence that a two-week continuous infusion with (−)nicotine in the intact rat leads to substantial and dose-related (0.03–0.3 mg/kg per h) reductions of basic fibroblast growth factor messenger RNA levels in the ventral midbrain. These changes are not associated with changes in neuronal and glial basic fibroblast growth factor immunoreactivity in this region with the antibodies used. However, a one-week continuous infusion with (−)nicotine (0.125 mg/kg per h) failed to significantly alter the basic fibroblast growth factor messenger RNA levels in the ventral midbrain of solvent and 6-hydroxydopamine-injected rats and thus also the 6-hydroxydopamine-induced increase of basic fibroblast growth factor messenger RNA levels in the ventral midbrain of the lesioned side observed at this time-interval and known to be of astroglial origin [Chadi G. et al. (1994) Neuroscience61, 891–910]. In agreement, the 6-hydroxydopamine-induced depletion of dopamine in the neostriatum was unaltered by the nicotine treatment (0.125 mg/kg per h). Thus, chronic continuous (−)nicotine treatment may lead to a reduced basic fibroblast growth factor trophic tone in the ventral midbrain of the intact but not of the 6-hydroxydopamine-lesioned rat neither on the lesioned nor on the unlesioned side of the ventral midbrain.