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Maurizio Renna

Publications and source records attributed to Maurizio Renna.

7 recordsLinked to original sources
PubMed2006

Nitric oxide-induced endoplasmic reticulum stress activates the expression of cargo receptor proteins and alters the glycoprotein transport to the Golgi complex.

The endoplasmic reticulum Golgi intermediate compartment 53 protein recycles continuously between the endoplasmic reticulum and the Golgi complex and ensures the anterograde transport of specific glycoproteins with the assistance of the Multiple Clotting Factor Deficiency adaptor protein. Therefore, to analyze the effect of the endoplasmic reticulum stress on the secretory pathway beyond the endoplasmic reticulum, we analyzed the expression of both proteins in J774 macrophages incubated with the nitric oxide donor DETA NONOate or with thapsigargin. Both proteins accumulated progressively, by a transcriptional mechanism, in response to these inducers. Nitric oxide also induced a higher level of calreticulin and glucose regulated 78 protein, two endoplasmic reticulum proteins controlled by the unfolded protein response. Interestingly, nitric oxide induced the processing of the activating transcription factor 6alpha of the unfolded protein response, while thapsigargin also induced the activation of the transcription factor X-box Binding Protein 1. In addition, we showed that the accumulation of both transporters occurred simultaneously with the activation of endoplasmic reticulum-stress-dependent apoptosis, suggesting that these proteins may participate in the events that will eventually decide the fate of the cell. Induction of endoplasmic reticulum stress affected the rate of anterograde transport of a reporter glycoprotein, indicating that the endoplasmic reticulum to Golgi transport is remarkably impaired. Our results indicate that increased levels of cargo receptor proteins might have a function either in the quality control of protein folding in the endoplasmic reticulum or in the homeostasis of the intermediate compartment and Golgi complex during cell stress.

Activating Transcription Factor 6↗
PubMed2006

Altered states of consciousness: processed EEG in mental disease.

Due to increasing life expectancy and a rising elderly population in Europe, the incidence of mild cognitive impairment which may predict diseases like Alzheimer's Disease or Vascular Dementia, is rising. Neurophysiological techniques are simple and inexpensive tools for early diagnosis and provide useful and objective correlates of cognitive activity both in normal subjects and patients suffering from the above conditions. Cognitive impairment due to different mental disease is characterized by decreased power and coherence in the alpha/beta band, which suggests functional disconnection among cortical areas, whereas both power and coherence in the delta and theta bands increase as a sign of cortical deafferentation from subcortical structures. Quantification of power and phase relationship by bispectral analysis suggests the Bispectral Index could be a useful but simple tool for early diagnosis of mental disease.

Aged↗
PubMed2005

Preoperative use of enoxaparin increases the risk of postoperative bleeding and re-exploration in cardiac surgery patients.

OBJECTIVE: The purpose of this study was to investigate if the preoperative use of new platelet inhibitors and low-molecular-weight heparins may contribute to bleeding after cardiac surgery. DESIGN: Retrospective data review. SETTING: University teaching hospital. PARTICIPANTS: One hundred eleven patients divided in 5 groups. INTERVENTIONS: Patients were grouped according to preoperative antithrombotic regimen: group 1, control, no agents (n=55); group 2, clopidogrel (n=9); group 3, enoxaparin (n=17); group 4, any GP IIb/IIIa inhibitor (n=14); and group 5, any drug combination (n=15). Data included cumulative mediastinal chest tube drainage, allogeneic blood transfusions, total blood donor exposures, and re-exploration. MEASUREMENTS AND MAIN RESULTS: Use of any drug (groups 2-5) resulted in greater total blood transfusions and donor exposure (p=0.0003) than control, especially red cells (p=0.002) and platelets (p=0.006). A greater percentage of patients on enoxaparin required mediastinal re-exploration for nonsurgical bleeding versus control (3/17 v 0/55, p=0.001). The use of enoxaparin was associated with significantly higher chest tube output after the first 24 hours postoperatively (p=0.048). CONCLUSION: Newer antithrombotic agents were associated with greater transfusion rates and total donor exposures. Enoxaparin use was associated with greater overall blood loss and with higher incidence of mediastinal re-exploration. The relative risk-benefit ratio of reduced periprocedure morbidity versus increased bleeding complications has yet to be determined.

Analysis of Variance↗
PubMed2004

Heat shock induces preferential translation of ERGIC-53 and affects its recycling pathway.

ERGIC-53 is a lectin-like transport receptor protein, which recirculates between the ER and the Golgi complex and is required for the intracellular transport of a restricted number of glycoproteins. We show in this article that ERGIC-53 accumulates during the heat shock response. However, at variance with the unfolded protein response, which results in enhanced transcription of ERGIC-53 mRNA, heat shock leads only to enhanced translation of ERGIC-53 mRNA. In addition, the half-life of the protein does not change during heat shock. Therefore, distinct signal pathways of the cell stress response modulate the ERGIC-53 protein level. Heat shock also affects the recycling pathway of ERGIC-53. The protein rapidly redistributes in a more peripheral area of the cell, in a vesicular compartment that has a lighter sedimentation density on sucrose gradient in comparison to the compartment that contains the majority of ERGIC-53 at 37 degrees C. This effect is specific, as no apparent reorganization of the endoplasmic reticulum, intermediate compartment and Golgi complex is morphologically detectable in the cells exposed to heat shock. Moreover, the anterograde transport of two unrelated reporter proteins is not affected. Interestingly, MCFD2, which interacts with ERGIC-53 to form a complex required for the ER-to-Golgi transport of specific proteins, is regulated similarly to ERGIC-53 in response to cell stress. These results support the view that ERGIC-53 alone, or in association with MCFD2, plays important functions during cellular response to stress conditions.

5' Untranslated Regions↗
PubMed2003

Low baseline Bispectral Index of the electroencephalogram in patients with dementia.

UNLABELLED: The baseline value of the Bispectral Index (BIS) is 96-99 in the awake state. Patients with Alzheimer's disease or vascular dementia may show an increase in slow wave and a decrease in fast wave activity of the electroencephalogram (EEG). BIS is presumed to decrease with EEG slowing. We hypothesized that the baseline "awake" BIS is lower in dementia than in normal elderly patients. We studied 36 patients with Alzheimer's disease or multiinfarct dementia and 36 control patients aged >75 yr. Both groups were assessed with a Mini-Mental State Test. BIS (version 3.4) was recorded from a frontal derivation using an Aspect A-2000 EEG monitor. Off-line data analysis was also performed with the newer version 4.0 of the BIS algorithm. Fourteen of 36 (38%) dementia patients and 4 of 36 (11%) controls had mean baseline BIS 3.4 <93 (P = 0.006). Eighteen of 36 (50%) dementia patients and 8 of 36 (22%) controls had mean BIS 4.0 <93 (P = 0.026). Mean (95% confidence interval) BIS 3.4 was 92.9 (91-95) in the dementia and 96.1 (95-97) in the control group (P = 0.02). Values with BIS 4.0 were, respectively, 89.1 (86-92) and 94.7 (93-96) (P = 0.002). No significant difference was found in age, sex, activity from the electromyogram, and signal quality index. As expected, the difference in Mini-Mental State Test scores was significant (P < 0.0001). A significant proportion of patients with dementia shows a low baseline BIS. The utility of the BIS monitor in detecting dementia warrants further investigation. IMPLICATIONS: This prospective, controlled, observational study demonstrates that electroencephalogram slowing associated with dementia affects the Bispectral Index of the electroencephalogram. A significant proportion of patients with dementia have a lower than normal "awake" Bispectral Index.

Aged↗
PubMed2002

Biasing effect of the electromyogram on BIS: a controlled study during high-dose fentanyl induction.

OBJECTIVE: A biasing effect of the electromyogram (EMG) on the Bispectral Index (BIS) may explain discrepancies in previous studies assessing BIS in the presence of neuromuscular activity. Our aims were: to evaluate variations of BIS in the presence of high EMG activity associated with muscular rigidity after administration of high-dose fentanyl; to compare muscular rigidity, as measured by the EMG variable of the BIS monitor, in patients who were administered two different dosages of fentanyl at induction of cardiac anaesthesia. METHODS: 26 patients undergoing CABG surgery, after premedication with morphine 0.15 mg/kg, were randomized to receive either fentanyl 50 mcg/kg (group F) or fentanyl 10 mcg/kg plus etomidate 0.2 mg/kg (group EF). The induction dose was administered over 2 minutes. Patients were manually ventilated with O2 via face mask. Five minutes after induction was complete, patients were clinically assessed using the Responsiveness portion of the Observer's Assessment of Alertness/Sedation scale (OAAS). Haemodynamic data were recorded and arterial blood samples obtained at the time of OAAS observation. Patients were administered a neuromuscular blocking agent only after the OAAS assessment. BIS (3.4) was recorded from an A-2000 EEG monitor (Aspect Medical Systems) using disposable sensors (BIS Sensor, Aspect Medical Systems) applied per manufacturer's instructions. Data were recorded on a PC for off-line analysis. RESULTS: At the time of OAAS observation, mean (95% CI) BIS in group F was 85 (77-92) compared to 67 (56-79) in group EF (p = 0.01). Similarly, mean (95% CI) EMG was 50 dB (45-56) in F and 41 dB (35-47) in EF (p = 0.01). Correlation between BIS and EMG was very high (r2 = 0.88). OAAS scores were significantly higher in group F (p = 0.03). Non significant correlation was observed between BIS and OAAS scores (r2 = 0.32, p = 0.1). Backward stepwise multiple regression analysis including EMG, pH, CO2, O2 and OASS scores showed EMG as strong predictor of BIS (p < 0.0001, r2 = 0.7). Regression of EMG against BIS yielded the equation: BIS = 3.7 + (1.6 x EMG). CONCLUSION: During fentanyl-induced muscular rigidity BIS recordings reflect EMG variations. When assessing BIS in the absence of neuromuscular blockade, it is necessary to evaluate the effect of EMG on BIS before making conclusions about depth of sedation. Fentanyl-induced rigidity appears to be a dose-related phenomenon which the EMG variable of BIS 3.4 is able to quantify.

Aged↗