Long-Term Evolution of Activities of Daily Life (ADLs) in Critically Ill COVID-19 Patients, a Case Series

BACKGROUND

The most common long-term symptoms of critically ill COVID-19 patients are fatigue, dyspnea and mental confusion. Adequate monitoring of long-term morbidity, mainly analyzing the activities of daily life (ADLs), allows better patient management after hospital discharge. The aim was to report long-term ADL evolution in critically ill COVID-19 patients admitted to a COVID-19 center in Lugano (Switzerland).

METHODS

A retrospective analysis on consecutive patients discharged alive from ICU with COVID-19 ARDS was performed based on a follow-up one year after hospital discharge; ADLs were assessed through the Barthel index (BI) and the Karnofsky Performance Status (KPS) scale. The primary objective was to assess differences in ADLs at hospital discharge (acute ADLs) and one-year follow-up (chronic ADLs). The secondary objective was to explore any correlations between ADLs and multiple measures at admission and during the ICU stay.

RESULTS

A total of 38 consecutive patients were admitted to the ICU; a t-test analysis between acute and chronic ADLs through BI showed a significant improvement at one year post discharge (t = -5.211, p < 0.0001); similarly, every single task of BI showed the same results (p < 0.0001 for each task of BI). The mean KPS was 86.47 (SD 20.9) at hospital discharge and 99.6 at 1 year post discharge (p = 0.02). Thirteen (34%) patients deceased during the first 28 days in the ICU; no patient died after hospital discharge.

CONCLUSIONS

Based on BI and KPS, patients reached complete functional recovery of ADLs one year after critical COVID-19.

Dynamics of disease characteristics and clinical management of critically ill COVID-19 patients over the time course of the pandemic: an analysis of the prospective, international, multicentre RISC-19-ICU registry

Background

It remains elusive how the characteristics, the course of disease, the clinical management and the outcomes of critically ill COVID-19 patients admitted to intensive care units (ICU) worldwide have changed over the course of the pandemic.

Methods

Prospective, observational registry constituted by 90 ICUs across 22 countries worldwide including patients with a laboratory-confirmed, critical presentation of COVID-19 requiring advanced organ support. Hierarchical, generalized linear mixed-effect models accounting for hospital and country variability were employed to analyse the continuous evolution of the studied variables over the pandemic.

Results

Four thousand forty-one patients were included from March 2020 to September 2021. Over this period, the age of the admitted patients (62 [95% CI 60–63] years vs 64 [62–66] years, p < 0.001) and the severity of organ dysfunction at ICU admission decreased (Sequential Organ Failure Assessment 8.2 [7.6–9.0] vs 5.8 [5.3–6.4], p < 0.001) and increased, while more female patients (26 [23–29]% vs 41 [35–48]%, p < 0.001) were admitted. The time span between symptom onset and hospitalization as well as ICU admission became longer later in the pandemic (6.7 [6.2–7.2| days vs 9.7 [8.9–10.5] days, p < 0.001). The PaO₂/FiO₂ at admission was lower (132 [123–141] mmHg vs 101 [91–113] mmHg, p < 0.001) but showed faster improvements over the initial 5 days of ICU stay in late 2021 compared to early 2020 (34 [20–48] mmHg vs 70 [41–100] mmHg, p = 0.05). The number of patients treated with steroids and tocilizumab increased, while the use of therapeutic anticoagulation presented an inverse U-shaped behaviour over the course of the pandemic. The proportion of patients treated with high-flow oxygen (5 [4–7]% vs 20 [14–29], p < 0.001) and non-invasive mechanical ventilation (14 [11–18]% vs 24 [17–33]%, p < 0.001) throughout the pandemic increased concomitant to a decrease in invasive mechanical ventilation (82 [76–86]% vs 74 [64–82]%, p < 0.001). The ICU mortality (23 [19–26]% vs 17 [12–25]%, p < 0.001) and length of stay (14 [13–16] days vs 11 [10–13] days, p < 0.001) decreased over 19 months of the pandemic.

Conclusion

Characteristics and disease course of critically ill COVID-19 patients have continuously evolved, concomitant to the clinical management, throughout the pandemic leading to a younger, less severely ill ICU population with distinctly different clinical, pulmonary and inflammatory presentations than at the onset of the pandemic.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-022-04065-2.

Reply to Böning et al. Comment on “Ceruti et al. Temporal Changes in the Oxyhemoglobin Dissociation Curve of Critically Ill COVID-19 Patients. J. Clin. Med. 2022, 11, 788”

We would like to thank Böning et al. for all the important issues raised in the present commentary [...]

Nasogastric tube in mechanical ventilated patients: ETCO2 and pH measuring to confirm correct placement. A pilot study

Introduction

Nasogastric tube (NGT) placement is a procedure commonly performed in mechanically ventilated (MV) patients. Chest X-Ray is the diagnostic gold-standard to confirm its correct placement, with the downsides of requiring MV patients’ mobilization and of intrinsic actinic risk. Other potential methods to confirm NGT placement have shown lower accuracy compared to chest X-ray; end-tidal CO₂ (ETCO₂) and pH analysis have already been singularly investigated as an alternative to the gold standard. Aim of this study was to determine threshold values in ETCO₂ and pH measurement at which correct NGT positioning can be confirmed with the highest accuracy.

Materials & methods

This was a prospective, multicenter, observational trial; a continuous cohort of eligible patients was allocated with site into two arms. Patients underwent general anesthesia, orotracheal intubation and MV; in the first and second group we respectively assessed the difference between tracheal and esophageal ETCO₂ and between esophageal and gastric pH values.

Results

From November 2020 to March 2021, 85 consecutive patients were enrolled: 40 in the ETCO₂group and 45 in the pH group. The ETCO₂ ROC analysis for predicting NGT tracheal misplacement demonstrated an optimal ETCO₂ cutoff value of 25.5 mmHg, with both sensitivity and specificity reaching 1.0 (AUC 1.0, p < 0.001). The pH ROC analysis for predicting NGT correct gastric placement resulted in an optimal pH cutoff value of 4.25, with mild diagnostic accuracy (AUC 0.79, p < 0.001).

Discussion

In patients receiving MV, ETCO₂ and pH measurements respectively identified incorrect and correct NGT placement, allowing the identification of threshold values potentially able to improve correct NGT positioning.

Trial registration

NCT03934515 (www.clinicaltrials.gov).

Can a Glove-Coach Technology Significantly Increase the Efficacy of Cardiopulmonary Resuscitation on Non-healthcare Professionals? A Controlled Trial

Introduction: Cardiovascular accidents are the world's leading cause of death. A good quality cardiopulmonary resuscitation (CPR) can reduce cardiac arrest-associated mortality. This study aims to test the coaching system of a wearable glove, providing instructions during out-of-hospital CPR. Materials and Methods: We performed a single-blind, controlled trial to test non-healthcare professionals during a simulated CPR performed on an electronic mannequin. The no-glove group was the control. The primary outcome was to compare the accuracy of depth and frequency of two simulated CPR sessions. Secondary outcomes were to compare the decay of CPR performance and the percentage of the duration of accurate CPR. Results: About 130 volunteers were allocated to 1:1 ratio in both groups; mean age was 36 ± 15 years (min-max 21-64) and 62 (48%) were men; 600 chest compressions were performed, and 571 chest compressions were analyzed. The mean frequency in the glove group was 117.67 vs. 103.02 rpm in the control group (p < 0.001). The appropriate rate cycle was 92.4% in the glove group vs. 71% in the control group, with a difference of 21.4% (p < 0.001). Mean compression depth in the glove group was 52.11 vs. 55.17 mm in the control group (p < 0.001). A mean reduction of compression depth over time of 5.3 mm/min was observed in the control group vs. 0.83 mm/min of reduction in the glove group. Conclusion: Visual and acoustic feedbacks provided through the utilization of the glove's coaching system were useful for non-healthcare professionals' CPR performance.

Admission criteria in critically ill COVID-19 patients: A physiology-based approach

Introduction

The COVID-19 pandemic required careful management of intensive care unit (ICU) admissions, to reduce ICU overload while facing limitations in resources. We implemented a standardized, physiology-based, ICU admission criteria and analyzed the mortality rate of patients refused from the ICU.

Materials and methods

In this retrospective observational study, COVID-19 patients proposed for ICU admission were consecutively analyzed; Do-Not-Resuscitate patients were excluded. Patients presenting an oxygen peripheral saturation (SpO₂) lower than 85% and/or dyspnea and/or mental confusion resulted eligible for ICU admission; patients not presenting these criteria remained in the ward with an intensive monitoring protocol. Primary outcome was both groups’ survival rate. Secondary outcome was a sub analysis correlating SpO₂ cutoff with ICU admission.

Results

From March 2020 to January 2021, 1623 patients were admitted to our Center; 208 DNR patients were excluded; 97 patients were evaluated. The ICU-admitted group (n = 63) mortality rate resulted 15.9% at 28 days and 27% at 40 days; the ICU-refused group (n = 34) mortality rate resulted 0% at both intervals (p < 0.001). With a SpO₂ cut-off of 85%, a significant correlation was found (p = 0.009), but with a 92% a cut-off there was no correlation with ICU admission (p = 0.26). A similar correlation was also found with dyspnea (p = 0.0002).

Conclusion

In COVID-19 patients, standardized ICU admission criteria appeared to safely reduce ICU overload. In the absence of dyspnea and/or confusion, a SpO₂ cutoff up to 85% for ICU admission was not burdened by negative outcomes. In a pandemic context, the SpO₂ cutoff of 92%, as a threshold for ICU admission, needs critical re-evaluation.

Machine learning using the extreme gradient boosting (XGBoost) algorithm predicts 5-day delta of SOFA score at ICU admission in COVID-19 patients

Background

Accurate risk stratification of critically ill patients with coronavirus disease 2019 (COVID-19) is essential for optimizing resource allocation, delivering targeted interventions, and maximizing patient survival probability. Machine learning (ML) techniques are attracting increased interest for the development of prediction models as they excel in the analysis of complex signals in data-rich environments such as critical care.

Methods

We retrieved data on patients with COVID-19 admitted to an intensive care unit (ICU) between March and October 2020 from the RIsk Stratification in COVID-19 patients in the Intensive Care Unit (RISC-19-ICU) registry. We applied the Extreme Gradient Boosting (XGBoost) algorithm to the data to predict as a binary outcome the increase or decrease in patients' Sequential Organ Failure Assessment (SOFA) score on day 5 after ICU admission. The model was iteratively cross-validated in different subsets of the study cohort.

Results

The final study population consisted of 675 patients. The XGBoost model correctly predicted a decrease in SOFA score in 320/385 (83%) critically ill COVID-19 patients, and an increase in the score in 210/290 (72%) patients. The area under the mean receiver operating characteristic curve for XGBoost was significantly higher than that for the logistic regression model (0.86 vs. 0.69, P < 0.01 [paired t-test with 95% confidence interval]).

Conclusions

The XGBoost model predicted the change in SOFA score in critically ill COVID-19 patients admitted to the ICU and can guide clinical decision support systems (CDSSs) aimed at optimizing available resources.

Multidisciplinary team approach in critically ill COVID-19 patients reduced pronation-related complications rate: A retrospective cohort study

Background

In the pandemic scenario, critically ill COVID-19 patients' management presented an increased workload for Intensive Care Unit (ICU) nursing staff, particularly during pronation maneuvers, with high risk of complications. In this contest, some authors described an increase in complications incidence after pronation. An ICU Pronation Team (IPT) was implemented to support this maneuver.

Material and methods

Retrospective analysis was conducted on consecutive critically ill COVID-19 patients in COVID-19 Center in southern Switzerland, between March and April 2020. Aim of the study was to determine rates and characteristics of pronation-related complications managed by IPT according to standard protocols.

Results

Forty-two patients undergoing mechanical ventilation (MV) were enrolled; 296 prone/supine positioning were performed, with 3.52 cycles/patient. All patients were equipped with arterial line, central venous catheter, urinary catheter, 28 (66%) endotracheal tube, 8 (19%), tracheostomy, 6 (14%) dialysis catheter, 3 (7%) abdominal drainage and 8 (19%) femoral thermodilution catheter; mean BMI was 28.3 kg/m². One (0.3%) major complication was observed, while fourteen (33.3%) patients developed minor complications (pressure injuries). ICU length-of-stay and MV days correlated with both incidence (p = 0.029 and p = 0.015 respectively) and number (p = 0.001 and p = 0.001 respectively) of pressure sores (n = 27). Propensity matching score analysis did not show any protective factor of pronation regarding pressure injuries (p = 0.448). No other significant correlation was found.

Conclusion

Multidisciplinary healthcare professional management can reduce most severe complication related to pronation in critical care setting. Rather than from pronation, the persistent high rate of minor complications appeared to be related to disease severity.

Broad betacoronavirus neutralization by a stem helix-specific human antibody

The spillovers of betacoronaviruses in humans and the emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants highlight the need for broad coronavirus countermeasures. We describe five monoclonal antibodies (mAbs) cross-reacting with the stem helix of multiple betacoronavirus spike glycoproteins isolated from COVID-19 convalescent individuals. Using structural and functional studies, we show that the mAb with the greatest breadth (S2P6) neutralizes pseudotyped viruses from three different subgenera through the inhibition of membrane fusion, and we delineate the molecular basis for its cross-reactivity. S2P6 reduces viral burden in hamsters challenged with SARS-CoV-2 through viral neutralization and Fc-mediated effector functions. Stem helix antibodies are rare, oftentimes of narrow specificity, and can acquire neutralization breadth through somatic mutations. These data provide a framework for structure-guided design of pan-betacoronavirus vaccines eliciting broad protection.

Implications of early respiratory support strategies on disease progression in critical COVID-19: a matched subanalysis of the prospective RISC-19-ICU cohort

BACKGROUND

Uncertainty about the optimal respiratory support strategies in critically ill COVID-19 patients is widespread. While the risks and benefits of noninvasive techniques versus early invasive mechanical ventilation (IMV) are intensely debated, actual evidence is lacking. We sought to assess the risks and benefits of different respiratory support strategies, employed in intensive care units during the first months of the COVID-19 pandemic on intubation and intensive care unit (ICU) mortality rates.

METHODS

Subanalysis of a prospective, multinational registry of critically ill COVID-19 patients. Patients were subclassified into standard oxygen therapy ≥10 L/min (SOT), high-flow oxygen therapy (HFNC), noninvasive positive-pressure ventilation (NIV), and early IMV, according to the respiratory support strategy employed at the day of admission to ICU. Propensity score matching was performed to ensure comparability between groups.

RESULTS

Initially, 1421 patients were assessed for possible study inclusion. Of these, 351 patients (85 SOT, 87 HFNC, 87 NIV, and 92 IMV) remained eligible for full analysis after propensity score matching. 55% of patients initially receiving noninvasive respiratory support required IMV. The intubation rate was lower in patients initially ventilated with HFNC and NIV compared to those who received SOT (SOT: 64%, HFNC: 52%, NIV: 49%, p = 0.025). Compared to the other respiratory support strategies, NIV was associated with a higher overall ICU mortality (SOT: 18%, HFNC: 20%, NIV: 37%, IMV: 25%, p = 0.016).

CONCLUSION

In this cohort of critically ill patients with COVID-19, a trial of HFNC appeared to be the most balanced initial respiratory support strategy, given the reduced intubation rate and comparable ICU mortality rate. Nonetheless, considering the uncertainty and stress associated with the COVID-19 pandemic, SOT and early IMV represented safe initial respiratory support strategies. The presented findings, in agreement with classic ARDS literature, suggest that NIV should be avoided whenever possible due to the elevated ICU mortality risk.

Prevalence of microhematuria in renal colic and urolithiasis: a systematic review and meta-analysis

BACKGROUND

This systematic review and meta-analysis aims to investigate the prevalence of microhematuria in patients presenting with suspected acute renal colic and/or confirmed urolithiasis at the emergency department.

METHODS

A comprehensive literature search was conducted to find relevant data on prevalence of microhematuria in patients with suspected acute renal colic and/or confirmed urolithiasis. Data from each study regarding study design, patient characteristics and prevalence of microhematuria were retrieved. A random effect-model was used for the pooled analyses.

RESULTS

Forty-nine articles including 15'860 patients were selected through the literature search. The pooled microhematuria prevalence was 77% (95%CI: 73-80%) and 84% (95%CI: 80-87%) for suspected acute renal colic and confirmed urolithiasis, respectively. This proportion was much higher when the dipstick was used as diagnostic test (80 and 90% for acute renal colic and urolithiasis, respectively) compared to the microscopic urinalysis (74 and 78% for acute renal colic and urolithiasis, respectively).

CONCLUSIONS

This meta-analysis revealed a high prevalence of microhematuria in patients with acute renal colic (77%), including those with confirmed urolithiasis (84%). Intending this prevalence as sensitivity, we reached moderate values, which make microhematuria alone a poor diagnostic test for acute renal colic or urolithiasis. Microhematuria could possibly still important to assess the risk in patients with renal colic.

Pseudoatrial Flutter: When the Problem Lies Outside the Heart

Electrocardiogram (ECG) artifacts are a common problem in emergency medicine. Generally these artifacts are induced by movement disorders, which generate electrical interference with the ECG recording. If these disorders are not promptly recognized, consequences can lead to hospitalization and execution of unnecessary diagnostic tests, thereby increasing the costs and clinical risks such as nosocomial infections and thromboembolism. We present a pseudoatrial flutter generated by a Parkinson’s-like movement.

Persistent postdischarge pain and chronic postoperative pain after breast cancer surgery under general anesthesia and single-shot paravertebral block: incidence, characteristics and impact on quality of life and healthcare costs

Introduction: Breast surgery is associated with persistent postsurgical pain; usually related to poorly treated acute pain. Paravertebral block has been successfully employed in analgesic protocols for breast surgery; its impact on postdischarge pain (PDP) has not been investigated. The aim of this study was to assess characteristics of PDP after breast surgery, the development of chronic postoperative pain (CPP) and its impact on health care costs.

Methods: We conducted a retrospective, observational study on a continuous cohort of adult female patients undergoing local breast cancer surgery under combined anesthesia. All patients were interviewed 6 months after hospital discharge. The survey was specifically conceived to assess incidence, features and duration of PDP. The overall cost of additional healthcare resources consumed with a specific relationship to persistent PDP was estimated.

Results: A database of 244 patients was preliminarily analyzed. Of these, 188 were included in the following statistical analysis; 123 patients (65.2%) reported significant PDP, with a median intensity on NRS of 6 (IQR=2), more frequently described as burning and associated with paresthesia and/or hyperalgesia (87 patients, 46%). One hundred and six patients (56.5%) reported this pain as interfering with their normal daily activities, work and sleep. In 26.8% of cases (50 patients) symptoms lasted more than 1 month and in 28 patients (15.0%) pain became chronic. The majority of patients self-treated their pain with non-steroideal anti-inflammatory drugs, but in 50 patients (26.8%) this therapy was reported as ineffective. This additional consumption of healthcare resources led to a significant economical impact.

Conclusion: PDP and CPP seem to be common complications after breast cancer surgery, even if a combined anesthesia technique with a thoracic paravertebral block is performed, leading to severe consequences on patients’ quality of life and increasing consumption of healthcare resources after discharge.

Trial number: NCT03618459 (www.clinicaltrials.gov).

Enlarged vestibular aqueduct: Audiological and genetical features in children and adolescents

BACKGROUND

Enlarged Vestibular Aqueduct (EVA) is one of the most common congenital malformations associated with sensorineural or mixed hearing loss. The association between hearing loss and EVA is described in syndromic (i.e. Pendred Syndrome, BOR, Waardenburg) and non-syndromic disorders, as isolate or familiar mutations of the SLC26A4 gene. The audiological phenotype of the EVA syndrome is heterogeneous, the type and entity of hearing loss may vary and vertigo episodes might also be present.

OBJECTIVE

The aim of this retrospective study was to describe the clinical and genetic features of a group of adolescent subjects presenting an EVA clinical profile, considering the presence of SLC26A4 gene mutations.

METHODS

14 Caucasian patients were assessed (24 ears in total; 4 patients presented a monolateral EVA), 10 females and 4 males. Their age at the time of diagnosis was between 1 and 6 years (mean age 2.5 years). Subjects were assessed by an ENT microscopy evaluation with a complete audiometric assessment, CT & MRI scans and genetic tests for the evaluation of the pendrin gene mutations (SLC26A4).

RESULTS

Considering the presence of SLC26A4 mutations and thyroid function, we could identify three sub-groups of patients: group 1, non syndromic EVA (ns EVA, no SLC26A4 mutation and no thyroid dysfunction); group 2, EVA with DFNB4 (single SLC26A4 gene mutation and no thyroid dysfunction); group 3, EVA with Pendred Syndrome (two pathological mutation of SLC26A4 and thyromegaly with thyroid dysfunction). Patients of group 1 (ns-EVA) showed various degrees of hearing loss from mild (55%) to severe-profound (45%). In groups 2 (DFNB4) and 3 (PDS), the degree of hearing loss is severe to profound in 70-75% of the cases; middle and high frequencies are mainly involved.

CONCLUSIONS

The phenotypic expressions associated with the EVA clinical profile are heterogeneous. From the available data, it was not possible to identify a representative audiological profile, in any of the three sub-groups. The data suggest that: (i) a later onset of hearing loss is usually related to EVA, in absence of SLC26A4 gene mutations; and (ii) hearing loss is more severe in patients with SLC26A4 gene mutations (groups 2 and 3 of this study).

Aquaporin 4 expression on trigeminal satellite glial cells under normal and inflammatory conditions

Aims

Limited information is currently available for the expression and role of Aquaporin 4 (AQP4) (AQ4) in the peripheral nervous system (PNS). It has been demonstrated that AQP4 is expressed in sensory ganglia. Immunohistochemistry has revealed that satellite glial cells (SGCs) surrounding the cell bodies of the primary afferent sensory neurons in these sensory ganglia exclusively express AQP4 at a considerably lower level than what is seen in astrocytes. The pathophysiological relevance of AQP4 in peripheral nociception; however, remains unclear. Hence, this study aimed at investigating AQP4 expression in trigeminal neurons and SGCs under normal and inflammatory conditions relevant to craniofacial pain conditions.

Methods

Rat trigeminal ganglia (TG) were isolated from adult male Sprague-Dawley rats subjected to a model of trigeminal inflammation evoked by unilateral complete Freund’s adjuvant (CFA) injection in temporomandibular joint. Immunohistochemistry was performed on TG sections of CFA-treated animals. NeuN and GS markers were used for identification of neurons and SGCs, respectively. AQP4 expression was investigated in both ipsilateral and contralateral TG sections. The study protocol was approved by the local ethics committee.

Results

Co-localization of NeuN-AQP4 and GS-AQP4 were identified in both ipsi and contralateral trigeminal ganglia of the CFA-treated rats. However, we did not detect any difference between the ipsi- and contralateral side in terms of alteration in AQP4 receptor expression.

Conclusions

AQP4 was expressed both on trigeminal neurons and SGCs and CFA did not cause a remarkable change in AQP4 expression, when ipsilateral and contralateral TG of the test animals was compared. Previously, it has been shown that in a neuropathic pain model no difference is detectable between wild type and AQP4-deficient mice, for mechanical and thermal perception; however, in formalin pain model AQP4-deficient mice have higher thermal pain thresholds. Further investigation is required to clarify role of AQP4 in pain.

Misura con Angio-TC delle stenosi della biforcazione carotidea

Scopi del presente studio sono il confronto tra angio-TC ed angiografia digitalizzata intaarteriosa nello studio delle biforcazioni carotidee, la descrizione del metodo utilizzato in angio-TC per la quantificazione delle stenosi e la discussione dell'eventuale collocazione dell'angio-TC nel protocollo di studio di questa patologia.

La nostra casistica comprende 16 pazienti, 12 maschi e 4 femmine, di età compresa tra 52 e 78 anni, sottoposti preventivamente ad esame ultrasonografico delle biforcazioni carotidee, risultato positivo per patologia ateromasica.

Sono state studiate con angio-TC 32 biforcazioni carotidee, utilizzando un apparecchio Elscint CT Twin II.I dati sono stati acquisiti in maniera continua, con tecnica volumetrica (double helix - dual slice) per un tempo di scansione complessivo di 24 secondi. Sono stati somministrati 80 ml di mezzo di contrasto non ionico (300 mg I / 100 ml) per via endovenosa.

Le acquisizioni sono state ottenute utilizzando una collimazione del fascio di 2,5 mm ed una velocità di spostamento del tavolo di 3,7 mm / sec (pitch 0,7). Le immagini «angiografiche» sono state successivamente ricostruite utilizzando l'algoritmo «maximum intensity projection» (MIP). Tutti i pazienti sono stati sottoposti ad angiografia digitalizzata intraarteriosa; ogni biforcazione carotidea è stata analizzata attraverso almeno 2 proiezioni angiografiche.

La percentuale di stenosi è stata determinata secondo i criteri del North American Symptomatic Endarterectomy Trial (NASCET). Una concordanza globale tra le due metodiche nella misura dei diametri carotidei si è verificata in 23/32 casi (71,8%). La stenosi è stata sovrastimata dall'angio-TC rispetto all'angiografia digitalizzata in 6/32 casi (18,8%); in 3 casi (9,4%) la stenosi è stata sottostimata dall'angio-TC.

Aspetti peculiari dell'angio-TC sono la possibilità di analisi della biforcazione in qualsiasi proiezione (rotazione delle immagini MIP), la precisa misurazione delle stenosi (ottenibile nelle immagini assiali) e l'individuazione delle componenti molli e/o calcifiche delle placche ateromasiche. La rapidità di acquisizione dei dati riduce al minimo l'evenienza di artefatti da movimento.

A nostro parere l'angio-TC potrebbe essere attualmente eseguita dopo l'esame ultrasonografico e prima dell'eventuale endarterectomia per ottenere una ulteriore rappresentazione della biforcazione carotidea quando angio-RM e angiografia sono controindicate, quando l'angio-RM o l'angiografia forniscono reperti di dubbia interpretazione ed infine se necessario dimostrare la morfologia della placca o altre alterazioni della parete arteriosa (ad esempio aneurismi trombizzati).

Isospin Mixing in ^{80}Zr: From Finite to Zero Temperature

The isospin mixing was deduced in the compound nucleus ^{80}Zr at an excitation energy of E^{*}=54  MeV from the γ decay of the giant dipole resonance. The reaction ^{40}Ca+^{40}Ca at E_{beam}=136  MeV was used to form the compound nucleus in the isospin I=0 channel, while the reaction ^{37}Cl+^{44}Ca at E_{beam}=95  MeV was used as the reference reaction. The γ rays were detected with the AGATA demonstrator array coupled with LaBr_{3}:Ce detectors. The temperature dependence of the isospin mixing was obtained and the zero-temperature value deduced. The isospin-symmetry-breaking correction δ_{C} used for the Fermi superallowed transitions was extracted and found to be consistent with β-decay data.

Cerebrospinal fluid amounts of HLA-G in dimeric form are strongly associated to patients with MRI inactive multiple sclerosis

Background:

The relevance of human leukocyte antigen (HLA)-G in dimeric form in multiple sclerosis (MS) is still unknown.

Objective:

To investigate the contribution of cerebrospinal fluid (CSF) HLA-G dimers in MS pathogenesis.

Methods:

CSF amounts of 78-kDa HLA-G dimers were measured by western blot analysis in 80 MS relapsing–remitting MS (RRMS) patients and in 81 inflammatory and 70 non-inflammatory controls.

Results:

CSF amounts of 78kDa HLA-G dimers were more frequent in RRMS than in inflammatory ( p<0.01) and non-inflammatory controls ( p<0.001) and in magnetic resonance imaging (MRI) inactive than in MRI active RRMS ( p<0.00001).

Conclusion:

Our findings suggest that HLA-G dimers may be implicated in termination of inflammatory response occurring in MS.

Pattern of care and effectiveness of treatment for glioblastoma patients in the real world: Results from a prospective population-based registry. Could survival differ in a high-volume center?

BACKGROUND

As yet, no population-based prospective studies have been conducted to investigate the incidence and clinical outcome of glioblastoma (GBM) or the diffusion and impact of the current standard therapeutic approach in newly diagnosed patients younger than aged 70 years.

METHODS

Data on all new cases of primary brain tumors observed from January 1, 2009, to December 31, 2010, in adults residing within the Emilia-Romagna region were recorded in a prospective registry in the Project of Emilia Romagna on Neuro-Oncology (PERNO). Based on the data from this registry, a prospective evaluation was made of the treatment efficacy and outcome in GBM patients.

RESULTS

Two hundred sixty-seven GBM patients (median age, 64 y; range, 29-84 y) were enrolled. The median overall survival (OS) was 10.7 months (95% CI, 9.2-12.4). The 139 patients ≤aged 70 years who were given standard temozolomide treatment concomitant with and adjuvant to radiotherapy had a median OS of 16.4 months (95% CI, 14.0-18.5). With multivariate analysis, OS correlated significantly with KPS (HR = 0.458; 95% CI, 0.248-0.847; P = .0127), MGMT methylation status (HR = 0.612; 95% CI, 0.388-0.966; P = .0350), and treatment received in a high versus low-volume center (HR = 0.56; 95% CI, 0.328-0.986; P = .0446).

CONCLUSIONS

The median OS following standard temozolomide treatment concurrent with and adjuvant to radiotherapy given to (72.8% of) patients aged ≤70 years is consistent with findings reported from randomized phase III trials. The volume and expertise of the treatment center should be further investigated as a prognostic factor.

Isospin character of low-lying pygmy dipole states in 208Pb via inelastic scattering of 17O ions

The properties of pygmy dipole states in 208Pb were investigated using the 208Pb(17O, 17O'γ) reaction at 340 MeV and measuring the γ decay with high resolution with the AGATA demonstrator array. Cross sections and angular distributions of the emitted γ rays and of the scattered particles were measured. The results are compared with (γ, γ') and (p, p') data. The data analysis with the distorted wave Born approximation approach gives a good description of the elastic scattering and of the inelastic excitation of the 2+ and 3- states. For the dipole transitions a form factor obtained by folding a microscopically calculated transition density was used for the first time. This has allowed us to extract the isoscalar component of the 1- excited states from 4 to 8 MeV.

Lateral sinus thrombosis as a complication of acute mastoiditis

Lateral sinus thrombosis is a rare complication of middle ear diseases: in children, it is usually related to acute otitis media, but it is also found in adults with chronic otitis. It was more frequent in the pre-antibiotic era and mortality was high. The Authors present a paediatric case of lateral sinus thrombosis in which they describe the clinical approach and related literature.

Giant cell granuloma of the temporal bone: a case report

PROBLEM

Giant cell granuloma (GCG) is a rare nonneoplastic bone lesion that occurs mostly in the jawbones; few cases arise in the remainder of the skull, including the temporal bone. Previously, giant cell lesions of the temporal bone were regarded as giant cell tumours (GCT). The importance of distinguishing GCG from GCT lies in the presumed difference in prognosis; GCTs have higher rates of recurrence, metastasis, and malignant transformation.

METHODOLOGY

We describe the case of a 12-year-old child with temporal bone GCG extending to the middle cranial fossa. The patient underwent a subtotal petrosectomy via retroauricular approach, associated with resection of the zygomatic process.

RESULTS

No evidence of recurrence was found 36 months later.

CONCLUSION

The diagnosis of GCG was based on clinical history, histology, imaging, and response to treatment. The patient was treated with the standard surgical approach, and has a good outcome at three years follow-up.

Evaluation of acute perihematomal regional apparent diffusion coefficient abnormalities by diffusion-weighted imaging

In this study, we investigated 40 patients (18 male, 22 female; mean age = 64.5 +/- 11.0; GCS = 9 to 14) with acute supratentorial spontaneous intracerebral hemorrhage (SICH) at admission by using a 1-tesla magnetic resonance imaging (MRI) unit equipped for single-shot echo-planar spin-echo isotropic diffusion-weighted imaging (DWI) sequences. All DWI studies were obtained within 48 hours after symptom onset. Regional apparent diffusion coefficient (rADC) values were measured in 3 different regions of interest (ROIs) drawn freehand on the T2-weighted images at b 0 s/mm2 on every section in which hematoma was visible: 1) the perihematomal hyperintense area; 2) 1 cm of normal appearing brain tissue surrounding the perilesional hyperintense rim; 3) an area mirroring the region including the clot and perihematomal hyperintense area placed in the contralateral hemisphere. rADC mean values were higher in perihematomal hyperintense and in contralateral than in normal appearing areas (p < 0.001), with increased rADC mean levels in all regions examined. Our findings show that rADC values indicative of vasogenic edema were present in the perihematomal area and in normal appearing brain tissue located both ipsilateral and contralateral to the hematoma, with lower levels in non-injured areas located in the T2 hyperintense rim around the clot.

Assessment of acute spontaneous intracerebral hematoma by CT perfusion imaging

A single-section deconvolution-derived computerized tomographic perfusion imaging was performed in 45 patients (22 male and 23 female; mean age=69.89+/-10.07 years) with acute supratentorial spontaneous intracerebral hemorrhage. Mean rCBF and rCBV were lower in the hemorrhagic core than in the perihematomal low density area (p<0.001), and in the perihematomal low density area than in normal appearing brain parenchyma (p<0.001). Mean rMTT values were higher in perihematomal low density area than in normal appearing area (p<0.01) and in both hemorrhagic and perihematomal area than in controlateral ROI (p<0.001). There were no differences in rMTT mean values between hemorrhagic core and perihematomal area, as well as between normal appearing and controlateral areas. We found a concentric distribution of all CT perfusion parameters characterized by an improvement from the core to the periphery, with low perihematomal rCBF and rCBV values suggesting edema formation.

[Current epidemiological and clinical features meningitis in a northern Italian area]

Objectives: To study etiological, epidemiological and clinical features of 97 cases of acute meningitis. Methods: Ninety-seven cases of acute meningitis were examined in adult HIV-negative patients admitted to the Infectious Diseases Unit of the Azienda Ospedale-Universita S. Anna in Ferrara. Demographic, etiological, epidemiological and clinical data were analyzed. Results: All cases were divided into two groups according to the macroscopic aspect of cerebrospinal fluid (CSF): purulent CSF (50 cases) or non-purulent CSF (47 cases). Purulent CSF meningitis more frequently affected male patients (64% vs 47%) and older patients (average 52 vs 44 years). The main epidemiological features in both groups were underlying bacterial diseases (i.e. otomastoiditis and/or sinusitis in 50% of pneumococcal meningitis) and iatrogenic immunodeficiency. From a clinical point of view the following alterations in the state of consciousness (stupor, confusion and coma) were most frequently found in purulent meningitis. The following non purulent forms of meningitis were diagnosed: 5 tubercular, 3 viral infections, 2 by Listeria monocytogenes, 1 by Entoameba histolytica, 1 by Cryptococcus neoformans and 35 (74,4%) unknown causes. Purulent meningitis were: 20 (40%) Streptococcus pneumoniae, 10 Neisseria meningitidis, 3 Staphylococcus aureus, 2 Escherichia coli, 1 Haemophilus influenzae and 1 Pseudomonas aeruginosa; 13 cases were unidentified. From 1989 to 1993 and from 1994-98 both groups of meningitis increased; respectively from 17 to 30 cases for non-purulent meningitis and from 18 to 32 cases for purulent meningitis. Meningitis due to Streptococcus pneumoniae increased from 27.7% to 46.8% during the period 1994-98. Conclusions: The study shows the high incidence of pneumococcal meningitis, during 1994-98, because a large number of patients with sinusitis and otomastoiditis were observed. The incidence of meningococcal meningitis appears stable. These data confirm the importance of timely diagnosis and correct therapy for such infections with reserved prognosis.

A3 adenosine receptors in human astrocytoma cells: agonist-mediated desensitization, internalization, and down-regulation

A(3) adenosine receptor activation has been previously demonstrated to result in both neuroprotective and neurodegenerative effects, depending upon specific pathophysiological conditions. This dual effect may depend on receptor regulation mechanisms that are able to change receptor availability and/or function. In the present study, we investigated desensitization, internalization, and down-regulation of native A(3) adenosine receptors in human astrocytoma cells after exposure to the agonist 2-chloro-N6-(3-iodobenzyl)-N-methyl-5'-carbamoyladenosine (Cl-IBMECA). Cl-IBMECA induced a concentration-dependent inhibition of adenylyl cyclase activity with an EC(50) value of 2.9 +/- 0.1 nM. The effect was suggested to be mediated by A(3) adenosine receptor subtype by the use of selective adenosine receptor antagonists. Cell treatment with pertussis toxin abolished Cl-IBMECA-mediated inhibition of adenylyl cyclase activity, evidencing an A(3) receptor coupling to inhibitory G protein. Short-term exposure to the agonist Cl-IBMECA (100 nM) caused rapid receptor desensitization, within 15 min. Agonist-induced desensitization was accompanied by receptor internalization: A(3) adenosine receptor internalized with rapid kinetics, within 30 min, after cell exposure to 100 nM Cl-IBMECA. The localization of A(3) adenosine receptors on the plasma membrane and in intracellular compartments was directly revealed by immunogold electron microscopy. After desensitization, the removal of agonist led to the restoration of A(3) adenosine receptor functioning through receptor recycling to the cell surface within 120 min. Prolonged agonist exposure (1-24 h) resulted in a marked down-regulation of A(3) adenosine receptors that reached 21.9 +/- 2.88% of control value after 24 h. After down-regulation, the recovery of receptor functioning was slow (24 h) and associated with the restoration of receptor levels close to control values. In conclusion, our results demonstrated that A(3) receptors, in astrocytoma cells, are regulated after short- and long-term agonist exposure.

Temporal bone anomalies in the branchio-oto-renal syndrome: detailed computed tomographic and magnetic resonance imaging findings

OBJECTIVE

To inventory computed tomographic and magnetic resonance imaging findings in the branchio-oto-renal (BOR) syndrome.

STUDY DESIGN

A prospective computed tomographic and magnetic resonance imaging study on a family with the BOR syndrome.

SETTING

Department of medical imaging and magnetic resonance imaging at St. Jan Brugge, Brugge, Belgium.

PATIENTS

Eight affected members of a Belgian family. Younger affected family members were excluded because of their age.

RESULTS

Computed tomography showed inner ear malformations in all eight affected patients. Magnetic resonance imaging was performed on five patients and showed inner ear malformations. To define hypoplasia or congenital enlargement of the inner ear structures, measurements obtained from a control group of normal subjects were used for comparison. Almost symmetrical cochlear abnormalities were observed on the three-dimensional Fourier transformation-constructive interference in steady state images of the five patients who underwent magnetic resonance imaging; four had dysplasia of the cochlea, and one had hypoplasia. The vestibule was slightly enlarged in one patient; computed tomography and magnetic resonance imaging showed semicircular canal malformations. Magnetic resonance imaging clearly showed bilateral enlarged endolymphatic sacs and ducts, whereas computed tomography showed only unilateral widening of the vestibular aqueduct and borderline widening of the vestibular aqueduct. Magnetic resonance imaging showed bilateral hypoplasia of the cochlear branch of the eighth nerve in one patient.

CONCLUSION

Hypoplasia and dysplasia of the cochlea were consistent findings, and only magnetic resonance imaging was able to evaluate the intracochlear changes in detail and corrected computed tomography in most patients. Moreover, magnetic resonance imaging also detected bilateral hypoplasia of the cochlear branch of the eighth nerve in one patient. A widened vestibular aqueduct and a widened vestibular sac were frequent but not obligatory features of the BOR syndrome. Other malformations of the middle ear included a reduced middle ear cavity and malformations of the ossicular chain.

The A3 adenosine receptor induces cytoskeleton rearrangement in human astrocytoma cells via a specific action on Rho proteins

In previous studies, we have demonstrated that exposure of astroglial cells to A3 adenosine receptor agonists results in dual actions on cell survival, with "trophic" and antiapoptotic effects at nanomolar concentrations and induction of cell death at micromolar agonist concentrations. The protective actions of A3 agonists have been associated with a reinforcement of the actin cytoskeleton, which likely results in increased resistance of cells to cytotoxic stimuli. The molecular mechanisms at the basis of this effect and the signalling pathway(s) linking the A3 receptor to the actin cytoskeleton have never been elucidated. Based on previous literature data suggesting that the actin cytoskeleton is controlled by small GTP-binding proteins of the Rho family, in the study reported here we investigated the involvement of these proteins in the effects induced by A3 agonists on human astrocytoma ADF cells. The presence of the A3 adenosine receptor in these cells has been confirmed by immunoblotting analysis. As expected, exposure of human astrocytoma ADF cells to nanomolar concentrations of the selective A3 agonist 2-chloro-N6-(3-iodobenzyl)-adenosine-5'-N-methyluronamide (CI-IB-MECA) resulted in formation of thick actin positive stress fibers. Preexposure of cells to the C3B toxin that inactivates Rho-proteins completely prevented the actin changes induced by CI-IB-MECA. Exposure to the A3 agonist also resulted in significant reduction of Rho-GDI, an inhibitory protein known to maintain Rho proteins in their inactive state, suggesting a potentiation of Rho-mediated effects. This effect was fully counteracted by the concomitant exposure to the selective A3 receptor antagonist MRS1191. These results suggest that the reinforcement of the actin cytoskeleton induced by A3 receptor agonists is mediated by an interference with the activation/inactivation cycle of Rho proteins, which may, therefore, represent a biological target for the identification of novel neuroprotective strategies.

2-Chloro-adenosine induces a glutamate-dependent calcium response in C2C12 myotubes

Adenosine and its derivatives may induce acute changes, i.e., injury and death, in muscle cells. In the present work, we evaluated the intracellular calcium concentration in C2C12 myogenic cells differentiated in vitro to form myotubes and exposed to a metabolically stable analogue of adenosine, 2-chloro-adenosine. The compound was able to significantly modify ionic homeostasis by sensitizing muscle cells to the excitatory amino acid glutamate. A single exposure to glutamate led to a marked increase in intracellular calcium level. This is the first demonstration that adenosine analogues can regulate muscle cell integrity and function via an indirect increase of intracellular calcium ions.

Adenosine- and 2-chloro-adenosine-induced cytopathic effects on myoblastic cells and myotubes: involvement of different intracellular mechanisms

We recently suggested that, in muscular dystrophies, the excessive accumulation of adenosine as a result of an altered purine metabolism may contribute to progressive functional deterioration and muscle cell death. To verify this hypothesis, we have taken advantage of C2C12 myoblastic cells, which can be differentiated in vitro into multinucleated cells (myotubes). Exposure of both proliferating myoblasts and differentiated myotubes to adenosine or its metabolically-stable analog, 2-chloro-adenosine, resulted in apoptotic cell death and myotube disruption. Cytotoxicity by either nucleoside did not depend upon extracellular adenosine receptors, but, at least in part, by entry into cells via the membrane nitro-benzyl-thio-inosine-sensitive transporter. The adenosine kinase inhibitor, 5-iodotubercidin, prevented 2-chloro-adenosine-induced (but not adenosine-induced) effects, suggesting that an intracellular phosphorylation/activation reaction plays a key role in 2-chloro-adenosine-mediated cytotoxicity. Conversely, adenosine cytotoxicity was aggravated by the addition of homocysteine, suggesting that adenosine effects may be due to the accumulation of S-adenosyl-homocysteine, which blocks intracellular methylation-dependent reactions. Both nucleosides markedly disrupted the myotube structure via an effect on the actin cytoskeleton; however, also for myotubes, there were marked differences in the morphological alterations induced by these two nucleosides. These results show that adenosine and 2-chloro-adenosine induce apoptosis of myogenic cells via completely different metabolic pathways, and are consistent with the hypothesis that adenosine accumulation in dystrophic muscles may represent a novel pathogenetic pathway in muscle diseases.

A novel gliotic P2 receptor mediating cyclooxygenase-2 induction in rat and human astrocytes

In astrocytic cultures maintained in vitro, a brief challenge with the ATP analog alpha,beta methyleneATP (alpha,betameATP) results, 3 days later, in marked elongation of astrocytic processes, an event that resembles the astrocytic hypertrophy known to occur in vivo during reactive astrogliosis. alpha,beta meATP-induced effects were observed in primary astrocytes obtained from both rat striatum and cortex (a brain area highly involved in chronic neurodegenerative pathologies), as well as in human astrocytoma cells (ADF cells). Purine-induced gliosis could be reversed by the non-selective P2X/P2Y receptor antagonist pyridoxalphosphate-6-azophenyl-2', 4'-disulphonic acid (PPADS), but not by oxidized ATP (an antagonist of the P2X(7) receptor), in line with previous studies of our laboratory suggesting the involvement of a P2Y receptor subtype. Induction of reactive gliosis was preceded by increased expression of cyclooxygenase-2 (COX-2), an enzyme whose excessive activation has been implicated in both acute and chronic neurodegenerative diseases. The selective COX-2 inhibitor NS-398 prevented both purine-induced astrogliosis and the associated COX-2 induction, suggesting that inhibition of the transcription of the COX-2 gene may also contribute to the anti-inflammatory properties of this agent. Significant blockade of both alpha,beta meATP-mediated reactive gliosis and COX-2 induction was also observed with PPADS. These data suggest that COX-2 mediates P2Y receptor-induced reactive astrogliosis, and that antagonists selective for this receptor subtype may represent a novel class of anti-inflammatory agents of potential interest in acute and chronic neurological disorders characterized by an inflammatory component and reactive gliosis.

Apoptosis induced by 2-chloro-adenosine and 2-chloro-2'-deoxy-adenosine in a human astrocytoma cell line: differential mechanisms and possible clinical relevance

We have previously demonstrated that 2-chloro-adenosine (2-CA) can induce apoptosis of rat astroglial cells (Abbracchio et al. [1995] Biochem. Biophys. Res. Commun. 213:908-915). In the present study, we have characterized, for the first time, the effects induced on a human astrocytoma cell line (ADF cells) by both 2-CA and its related analog 2-chloro-2'-deoxy-adenosine (2-CdA, that is employed as anti-cancer agent in chronic lymphoid malignancies). Exposure of these cells to either adenosine analog resulted in time- and concentration-dependent apoptosis. Experiments with pharmacological agents known to interfere with adenosine receptors, its membrane transporter, and intracellular nucleoside kinases showed that: (i) cell death induced by either adenosine analog did not depend on extracellular adenosine receptors, but on a direct intracellular action; however, only in the case of 2-CA, was entry into cells mediated by the specific nitrobenzyl-tioinosine-sensitive transporter; (ii) for both adenosine analogs, induction of apoptosis required the phosphorylation/activation by specific intracellular nucleoside kinases, i.e., adenosine kinase for 2-CA, and deoxycytidine kinase for 2-CdA. In addition, only in the case of 2-CdA, was induction of apoptosis preceded by a block of cells at the G2/M phase of the cell cycle. Finally, at concentrations of either analog that killed about 80-90% of astrocytoma cells, a significantly lower effect on the viability of primary cortical neurons was observed. In conclusion, both adenosine analogs can trigger apoptosis of human astrocytoma cells, albeit with different mechanisms. This effect together with the relative sparing of neuronal cells, may have potential clinical implications for the therapy of tumors of glial origin.

Activation of the A3 adenosine receptor affects cell cycle progression and cell growth

The A3 adenosine receptor has been implicated in modulation of cell growth. As a first step to the characterization of the underlying mechanisms, we exposed Chinese hamster ovary (CHO) cells transfected with the human A3 receptor (A3R-CHO) to selective A3 receptor ligands. At micromolar concentrations, the A3 agonists N6-(3-iodobenzyl)-adenosine-5'-N-methyluronamide (IB-MECA) and its 2-chloro derivative Cl-IB-MECA reduced cell number, with no effects on either parental CHO cells (not expressing any adenosine receptor), or CHO cells transfected with the human A1 receptor. Cl-IB-MECA also reduced cell number in the human HEK293 cell line transfected with the human A3 receptor cDNA as opposed to the respective untransfected wild-type cells. In A3R-CHO, agonist-induced effects were antagonized by nanomolar concentrations of A3 antagonists, including the triazoloquinazoline derivative MRS 1220, the dihydropyridine derivative MRS 1191, and the triazolonaphthyridine derivative L-249,313. A3 agonist-induced effects were not due to modulation of cell adhesion, nor to necrosis or apoptosis. Growth curves revealed highly impeded growth, and flow-cytometric analysis showed markedly reduced bromodeoxyuridine incorporation into nuclei. The effect on cell cycle was completely antagonized by MRS1191. Hence, activation of the human A3 receptor in A3R-CHO results in markedly impaired cell cycle progression, suggesting an important role for this adenosine receptor subtype in cell cycle regulation and cell growth.

Apoptosis by 2-chloro-2'-deoxy-adenosine and 2-chloro-adenosine in human peripheral blood mononuclear cells

Adenosine has profound effects on immune cells and has been implicated in the intrathymic apoptotic deletion of T-cells during development. In order to characterize adenosine effects on quiescent peripheral blood mononuclear cells (PBMC), we have evaluated the ability of the previously characterized adenosine receptor agonist 2-chloro-adenosine (2CA; Ceruti, Barbieri et al., 1997) and of the antineoplastic drug 2-chloro-2'-deoxy-adenosine (2CdA, cladribine) to trigger apoptosis of PBMC. Apoptosis was assessed by morphological changes, DNA fragmentation by agarose gel electrophoresis and appearance of hypodiploid DNA peak by flow cytometry. 2CA (10 microM) and 2CdA (1 microM) induced apoptosis in human PBMC, which are relatively insensitive to apoptosis. For both agents, the effect was concentration- and time-dependent, although 2CdA induced apoptosis more potently than 2CA. Evaluation of mitochondrial function in parallel samples using the mitochondrial membrane-potential-specific dye JC-1 showed that mitochondrial damage followed the same kinetics as apoptosis, hence an early damage of mitochondria is likely not responsible for adenosine-induced death of PBMC. The effect of 2CA was partially prevented by addition of dipyridamole (DP), a nucleoside transport inhibitor, hence some of the apoptotic effect of this nucleoside is, at least in part, due to intracellular action. Alternatively, DP did not affect 2CdA-induced apoptosis, suggesting that 2CdA may enter cells via a DP-insensitive transporter. 5-Iodotubercidin (5-Itu), a nucleoside kinase inhibitor, was also able to partially prevent the action of 2CA and was not able to affect 2CdA-induced apoptosis, suggesting a different role for phosphorylation in 2CA- vs 2CdA-induced apoptosis. To test the role of P1 receptors, agonists and antagonists selective at various P1 receptor subtypes were used. Data suggest that, for 2CA, apoptosis is partially sustained by activation of the A2A receptor subtype, whereas no role is exerted by P1 receptors in 2CdA-dependent apoptosis. Moreover, in these cells, apoptosis could also be triggered through intense activation of the A3 receptor via selective agonists such as 2-chloro-N6-(3-iodobenzyl)adenosine-5'-N-methyluronamide (Cl-IB-MECA), but this mechanism plays no role in either 2CA- or 2CdA-induced apoptosis. On the whole, our results suggest that 2CA and 2CdA follow different pathways in inducing apoptosis of immune cells. Moreover, our data also suggest that there are at least three different ways by which adenosine derivatives may induce apoptosis of human PBMC: (i) through an A2A-like extracellular membrane receptor; (ii) through entry of nucleosides into cells and direct activation of intracellular events involved in the apoptotic process; or (iii) through activation of the A3 receptor.

The A3 adenosine receptor mediates cell spreading, reorganization of actin cytoskeleton, and distribution of Bcl-XL: studies in human astroglioma cells

The pathophysiological role of the adenosine A3 receptor in the central nervous system is largely unknown. We have investigated the effects of the selective A3 receptor agonist 2-chloro-N6-(3-iodobenzyl)-adenosine, Cl-IB-MECA, in cells of the astroglial lineage (human astrocytoma ADF cells). A marked reorganization of the cytoskeleton, with appearance of stress fibers and numerous cell protrusions, was found following exposure of cells to low (nM) concentrations of Cl-IB-MECA. These "trophic" effects were accompanied by induction of the expression of Rho, a small GTP-binding protein, which was virtually absent in control cells, and by changes of the intracellular distribution of the antiapoptotic protein Bcl-XL, that, in agonist-exposed cells, became specifically associated to cell protrusions. This is the first demonstration that the intracellular organization of Bcl-XL can be modulated by the activation of a G-protein-coupled membrane receptor, such as the A3 adenosine receptor. Moreover, modulation of the astrocytic cytoskeleton by adenosine may have intriguing implications in both nervous system development and in the response of the brain to trauma and ischemia.

Characterization of the signalling pathways involved in ATP and basic fibroblast growth factor-induced astrogliosis

1. A brief challenge of rat astrocytes with either alpha, beta-methyleneATP (alpha, beta-meATP) or basic fibroblast growth factor (bFGF) resulted, three days later, in morphological differentiation of cells, as shown by marked elongation of astrocytic processes. The P2 receptor antagonist suramin prevented alpha, beta-meATP- but not bFGF-induced astrocytic elongation. Similar effects on astrocytic elongation were also observed with ATP and other P2 receptor agonists (beta, gamma meATP, ADP beta S, 2meSATP and, to a lesser extent, UTP). 2. Pertussis toxin completely abolished alpha, beta-meATP- but not bFGF-induced effects. No effects were exerted by alpha, beta-meATP on cyclic AMP production; similarly, neomycin had no effects on elogation of processes induced by the purine analogue, suggesting that adenylyl cyclase and phospholipase C are probably not involved in alpha, beta-meATP-induced effects (see also the accompanying paper by Centemeri et al., 1997). The tyrosine-kinase inhibitor genistein greatly reduced bFGF- but not alpha, beta-meATP-induced astrocytic elongation. 3. Challenge of cultures with alpha, beta-meATP rapidly and concentration-dependently increased [3H]-arachidonic acid (AA) release from cells, suggesting that activation of phospholipase A2 (PLA2) may be involved in the long-term functional effects evoked by purine analogues. Consistently, exogenously added AA markedly elongated astrocytic processes. Moreover, various PLA2 inhibitors (e.g. mepacrine and dexamethasone) prevented both the early alpha, beta-meATP-induced [3H]-AA release and/or the associated long-term morphological changes, without affecting the astrocytic elongation induced by bFGF. Finally, the protein kinase C (PKC) inhibitor H7 fully abolished alpha, beta-meATP- but not bFGF-induced effects. 4. Both alpha, beta-meATP and bFGF rapidly and transiently induced the nuclear accumulation of Fos and Jun. Both c-fos and c-jun induction by the purine analogue could be fully prevented by pretreatment with suramin. In contrast, the effects of bFGF were unaffected by this P2 receptor antagonist. 5. It was concluded that alpha, beta-meATP- and bFGF-morphological differentiation of astrocytes occurs via independent transductional pathways. For the purine analogue, signalling involves a Gi/G(o) protein-coupled P2Y-receptor which may be linked to activation of PLA2 (involvement of an arachidonate-sensitive PKC is speculated); for bFGF, a tyrosine kinase receptor is involved. Both pathways merge on some common intracellular target, as suggested by induction of primary response genes, which in turn may regulate late response genes mediating long-term phenotypic changes of astroglial cells. 6. These findings implicate P2 receptors as novel targets for the pharmacological regulation of reactive astrogliosis, which has intriguing implications in nervous system diseases characterized by degenerative events.

Different pathways of apoptosis revealed by 2-chloro-adenosine and deoxy-D-ribose in mammalian astroglial cells

Both the adenosine analogue 2-chloro-adenosine (2-CA) and the reducing sugar deoxy-D-ribose (dRib) induce apoptosis of astroglial cells in rat brain primary cultures (Abbracchio et al.: Biochem Biophys Res Commun 213:908-915, 1995). The present study was undertaken to elucidate by both morphological and cytofluorimetric analyses the intracellular mechanism(s) involved in induction of apoptosis by these two agents. The poly(ADP-ribose)polymerase (PARP) inhibitor 3-aminobenzamide did not prevent either 2-CA- or dRib-induced cell death, suggesting that activation of PARP is not critically important for induction of apoptosis in astrocytes. The radical scavenger N-acetyl-cysteine (NAC) strongly inhibited dRib- but not 2-CA-induced cell death, suggesting a differential role for radical formation in apoptosis by these two agents. A time-dependent increase of cells with depolarized mitochondria was observed in dRib-, and to a lesser extent, in 2-CA-treated cultures. NAC also prevented dRib- but not 2-CA-induced mitochondrial changes. We conclude that, in mammalian astrocytes, apoptosis can proceed through diverse and multiple pathways, depending upon the apoptotic stimulus. For dRib, apoptosis likely proceeds through generation of radicals and mitochondrial involvement. An adenosine extracellular receptor linked to an as yet unidentified signaling pathway may instead mediate 2-CA-induced cell death, which may have intriguing implications for both nervous system development and brain response to trauma and ischemia.

[Diagnostic imaging of osteoid osteoma]

Conventional radiography, bone scintigraphy and Computed Tomography (CT) are the most useful tools to identify osteoid osteomas. We examined 26 patients (14 men and 12 women) with osteoid osteoma in different skeletal sites (13 femora, 3 tibiae, 3 hands, 2 peroneal bones, 2 humera, 2 spines and 1 talus) and compared the diagnostic yield of the above techniques. The fundamental radiographic findings in this benign bone lesion are the presence of a "nidus", with or without calcifications, perilesional sclerosis and periosteal new bone formation. Four patients in our series had soft tissue edema. In the majority of cases, conventional radiography is the imaging method of choice, because it is easily available and its diagnostic yield is adequate (17 patients in our series), especially if combined with bone scintigraphy-whose high diagnostic sensitivity was proved in all of our patients. CT is recommended for its better spatial resolution, in view of surgery, especially when soft tissues are involved. MRI is a highly valuable tool in bone tumor staging because it demonstrates cortical involvement and intramedullary and soft tissue spread. However, MR findings might be misinterpreted as indicating a more aggressive pathologic process.