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Hodson D, Mistry H, Yates J, Guzzetti S, Davies M, Aarons L, Ogungbenro K. Hierarchical cluster analysis and nonlinear mixed-effects modelling for candidate biomarker detection in preclinical models of cancer. Eur J Pharm Sci 2024; 197:106774. [PMID: 38641123 DOI: 10.1016/j.ejps.2024.106774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Revised: 04/16/2024] [Accepted: 04/17/2024] [Indexed: 04/21/2024]
Abstract
BACKGROUND Preclinical models of cancer can be of translational benefit when assessing how different biomarkers are regulated in response to particular treatments. Detection of molecular biomarkers in preclinical models of cancer is difficult due inter-animal variability in responses, combined with limited accessibility of longitudinal data. METHODS Nonlinear mixed-effects modelling (NLME) was used to analyse tumour growth data based on expected tumour growth rates observed 7 days after initial doses (DD7) of Radiotherapy (RT) and Combination of RT with DNA Damage Response Inhibitors (DDRi). Cox regression was performed to confirm an association between DD7 and survival. Hierarchical Cluster Analysis (HCA) was then used to identify candidate biomarkers impacting responses to RT and RT/DDRi and these were validated using NLME. RESULTS Cox regression confirmed significant associations between DD7 and survival. HCA of RT treated samples, combined with NLME confirmed significant associations between DD7 and Cluster specific CD8+ Ki67 MFI, as well as DD7 and cluster specific Natural Killer cell density in RT treated mice. CONCLUSION Application of NLME, as well as HCA of candidate biomarkers may provide additional avenues to assess the effect of RT in MC38 syngeneic tumour models. Additional studies would need to be conducted to confirm association between DD7 and biomarkers in RT/DDRi treated mice.
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Affiliation(s)
- David Hodson
- Division of Pharmacy and Optometry, Faculty of Biology, Medicine and Health, Stopford Building, University of Manchester, Manchester M13 9PT, UK
| | - Hitesh Mistry
- Division of Pharmacy and Optometry, Faculty of Biology, Medicine and Health, Stopford Building, University of Manchester, Manchester M13 9PT, UK
| | - James Yates
- DMPK, Research and Early Development, Oncology R&D, AstraZeneca, Cambridge, UK
| | - Sofia Guzzetti
- DMPK, Research and Early Development, Oncology R&D, AstraZeneca, Cambridge, UK
| | - Michael Davies
- DMPK, Research and Early Development, Neuroscience R&D, AstraZeneca, Cambridge, UK
| | - Leon Aarons
- Division of Pharmacy and Optometry, Faculty of Biology, Medicine and Health, Stopford Building, University of Manchester, Manchester M13 9PT, UK
| | - Kayode Ogungbenro
- Division of Pharmacy and Optometry, Faculty of Biology, Medicine and Health, Stopford Building, University of Manchester, Manchester M13 9PT, UK.
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Staniszewska AD, Pilger D, Gill SJ, Jamal K, Bohin N, Guzzetti S, Gordon J, Hamm G, Mundin G, Illuzzi G, Pike A, McWilliams L, Maglennon G, Rose J, Hawthorne G, Cortes Gonzalez M, Halldin C, Johnström P, Schou M, Critchlow SE, Fawell S, Johannes JW, Leo E, Davies BR, Cosulich S, Sarkaria JN, O'Connor MJ, Hamerlik P. Preclinical Characterization of AZD9574, a Blood-Brain Barrier Penetrant Inhibitor of PARP1. Clin Cancer Res 2024; 30:1338-1351. [PMID: 37967136 DOI: 10.1158/1078-0432.ccr-23-2094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 10/04/2023] [Accepted: 11/09/2023] [Indexed: 11/17/2023]
Abstract
PURPOSE We evaluated the properties and activity of AZD9574, a blood-brain barrier (BBB) penetrant selective inhibitor of PARP1, and assessed its efficacy and safety alone and in combination with temozolomide (TMZ) in preclinical models. EXPERIMENTAL DESIGN AZD9574 was interrogated in vitro for selectivity, PARylation inhibition, PARP-DNA trapping, the ability to cross the BBB, and the potential to inhibit cancer cell proliferation. In vivo efficacy was determined using subcutaneous as well as intracranial mouse xenograft models. Mouse, rat, and monkey were used to assess AZD9574 BBB penetration and rat models were used to evaluate potential hematotoxicity for AZD9574 monotherapy and the TMZ combination. RESULTS AZD9574 demonstrated PARP1-selectivity in fluorescence anisotropy, PARylation, and PARP-DNA trapping assays and in vivo experiments demonstrated BBB penetration. AZD9574 showed potent single agent efficacy in preclinical models with homologous recombination repair deficiency in vitro and in vivo. In an O6-methylguanine-DNA methyltransferase (MGMT)-methylated orthotopic glioma model, AZD9574 in combination with TMZ was superior in extending the survival of tumor-bearing mice compared with TMZ alone. CONCLUSIONS The combination of three key features-PARP1 selectivity, PARP1 trapping profile, and high central nervous system penetration in a single molecule-supports the development of AZD9574 as the best-in-class PARP inhibitor for the treatment of primary and secondary brain tumors. As documented by in vitro and in vivo studies, AZD9574 shows robust anticancer efficacy as a single agent as well as in combination with TMZ. AZD9574 is currently in a phase I trial (NCT05417594). See related commentary by Lynce and Lin, p. 1217.
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Affiliation(s)
| | - Domenic Pilger
- Bioscience, Oncology R&D, AstraZeneca, Cambridge, United Kingdom
| | - Sonja J Gill
- Oncology Safety, Clinical Pharmacology and Safety Sciences, R&D, AstraZeneca, Cambridge, United Kingdom
| | - Kunzah Jamal
- Bioscience, Oncology R&D, AstraZeneca, Cambridge, United Kingdom
| | - Natacha Bohin
- Oncology Safety, Clinical Pharmacology and Safety Sciences, R&D, AstraZeneca, Cambridge, United Kingdom
| | - Sofia Guzzetti
- DMPK, Oncology R&D, AstraZeneca, Cambridge, United Kingdom
| | - Jacob Gordon
- Oncology R&D, AstraZeneca, Boston, Massachusetts
| | - Gregory Hamm
- Imaging and Data Analytics, Clinical Pharmacology and Safety Sciences, R&D, AstraZeneca, Cambridge, United Kingdom
| | - Gill Mundin
- DMPK, Oncology R&D, AstraZeneca, Cambridge, United Kingdom
| | - Giuditta Illuzzi
- Bioscience, Oncology R&D, AstraZeneca, Cambridge, United Kingdom
| | - Andy Pike
- DMPK, Oncology R&D, AstraZeneca, Cambridge, United Kingdom
| | - Lisa McWilliams
- Discovery Sciences, R&D, AstraZeneca, Cambridge, United Kingdom
| | - Gareth Maglennon
- Pathology, Clinical Pharmacology and Safety Sciences, R&D, AstraZeneca, Cambridge, United Kingdom
| | - Jonathan Rose
- Animal Sciences and Technologies, Clinical Pharmacology and Safety Sciences, R&D, AstraZeneca, Cambridge, United Kingdom
| | - Glen Hawthorne
- Integrated Bioanalysis, Clinical Pharmacology and Safety Sciences, R&D, AstraZeneca, Cambridge, United Kingdom
| | | | - Christer Halldin
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Peter Johnström
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
- PET Science Centre at Karolinska Institutet, Precision Medicine and Biosamples, Oncology R&D, Stockholm, Sweden
| | - Magnus Schou
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
- PET Science Centre at Karolinska Institutet, Precision Medicine and Biosamples, Oncology R&D, Stockholm, Sweden
| | | | | | | | - Elisabetta Leo
- Bioscience, Oncology R&D, AstraZeneca, Cambridge, United Kingdom
| | - Barry R Davies
- Projects Group, Oncology R&D, AstraZeneca, Cambridge, United Kingdom
| | - Sabina Cosulich
- Projects Group, Oncology R&D, AstraZeneca, Cambridge, United Kingdom
| | | | - Mark J O'Connor
- Bioscience, Oncology R&D, AstraZeneca, Cambridge, United Kingdom
| | - Petra Hamerlik
- Bioscience, Oncology R&D, AstraZeneca, Cambridge, United Kingdom
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Hodson D, Mistry H, Guzzetti S, Davies M, Staniszewska A, Farrington P, Cadogan E, Yates J, Aarons L, Ogungbenro K. Mixed effects modeling of radiotherapy in combination with immune checkpoint blockade or inhibitors of the DNA damage response pathway. CPT Pharmacometrics Syst Pharmacol 2023; 12:1640-1652. [PMID: 37722071 PMCID: PMC10681475 DOI: 10.1002/psp4.13026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Revised: 07/08/2023] [Accepted: 07/17/2023] [Indexed: 09/20/2023] Open
Abstract
Dosage optimization to maximize efficacy and minimize toxicity is a potential issue when administering radiotherapy (RT) in combination with immune checkpoint blockade (ICB) or inhibitors of the DNA Damage Response Pathway (DDRi) in the clinic. Preclinical models and mathematical modeling can help identify ideal dosage schedules to observe beneficial effects of a tri-therapy. The aim of this study is to describe a mathematical model to capture the impact of RT in combination with inhibitors of the DNA Damage Response Pathway or blockade of the immune checkpoint protein - programmed death ligand 1 (PD-L1). This model describes how RT mediated activation of antigen presenting cells can induce an increase in cytolytic T cells capable of targeting tumor cells, and how combination drugs can potentiate the immune response by inhibiting the rate of T cell exhaustion. The model was fitted using preclinical data, where MC38 tumors were treated in vivo with RT alone or in combination with anti-PD-L1 as well as with either olaparib or the ataxia telangiectasia mutated (ATM) inhibitor-AZD0156. The model successfully described the observed data and goodness-of-fit, using visual predictive checks also confirmed a successful internal model validation for each treatment modality. The results demonstrated that the anti-PD-L1 effect in combination with RT was maximal in vivo and any additional benefit of DDRi at the given dosage and schedule used was undetectable. Model fit results indicated AZD0156 to be a more potent DDRi than olaparib. Simulations of alternative doses indicated that reducing efficacy of anti-PD-L1 by 68% would potentially provide evidence for a benefit of ATM inhibition in combination with ICB and increase the relative efficacy of tri-therapy.
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Affiliation(s)
- David Hodson
- Division of Pharmacy and Optometry, Faculty of Biology, Medicine and HealthThe University of ManchesterManchesterUK
| | - Hitesh Mistry
- Division of Pharmacy and Optometry, Faculty of Biology, Medicine and HealthThe University of ManchesterManchesterUK
| | - Sofia Guzzetti
- DMPK, Research and Early Development, Oncology R&DAstraZenecaCambridgeUK
| | - Michael Davies
- DMPK, Research and Early Development, Neuroscience R&DAstraZenecaCambridgeUK
| | - Anna Staniszewska
- Bioscience, Research and Early Development, Oncology R&DAstraZenecaCambridgeUK
| | - Paul Farrington
- Bioscience, Research and Early Development, Oncology R&DAstraZenecaCambridgeUK
| | - Elaine Cadogan
- Bioscience, Research and Early Development, Oncology R&DAstraZenecaCambridgeUK
| | | | - Leon Aarons
- Division of Pharmacy and Optometry, Faculty of Biology, Medicine and HealthThe University of ManchesterManchesterUK
| | - Kayode Ogungbenro
- Division of Pharmacy and Optometry, Faculty of Biology, Medicine and HealthThe University of ManchesterManchesterUK
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Hodson D, Mistry H, Yates J, Farrington P, Staniszewska A, Guzzetti S, Davies M, Aarons L, Ogungbenro K. Radiation in Combination with Immune Checkpoint Blockade and DNA Damage Response Inhibitors in Mice: Dosage Optimization in MC38 Syngeneic Tumors via Modelling and Simulation. J Pharmacol Exp Ther 2023; 387:44-54. [PMID: 37348964 DOI: 10.1124/jpet.122.001572] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 05/23/2023] [Accepted: 06/09/2023] [Indexed: 06/24/2023] Open
Abstract
Clinical trials assessing the impact of radiotherapy (RT) in combination with DNA damage response pathway inhibitors (DDRis) and/or immune checkpoint blockade are currently ongoing. However, current methods for optimizing dosage and schedule are limited. A mathematical model was developed to capture the impacts of RT in combination with DDRi and/or anti-PD-L1 [immune checkpoint inhibitor (ICI)] on tumor immune interactions in the MC38 syngeneic tumor model. The model was fitted to datasets that assessed the impact of RT in combination with the DNA protein kinase inhibitor (DNAPKi) AZD7648. The model was further fitted to datasets from studies that were used to assess both RT/ICI combinations as well as RT/ICI combinations followed by concurrent administration of the poly ADP ribose polymerase inhibitor (PARPi) olaparib. Nonlinear mixed-effects modeling was performed followed by internal validation with visual predictive checks (VPC). Simulations of alternative dosage regimens and scheduling were performed to identify optimal candidate dosage regimens of RT/DNAPKi and RT/PARPi/ICI. Model fits and VPCs confirmed a successful internal validation for both datasets and demonstrated very small differences in the median, lower, and upper percentile values of tumor diameters between RT/ICI and RT/PARPi/ICI, which indicated that the triple combination of RT/PARPi/ICI at the given dosage and schedule does not provide additional benefit compared with ICI in combination with RT. Simulation of alternative dosage regimens indicated that lowering the dosage of ICI to between 2 and 4 mg/kg could induce similar benefits to the full dosage regimen, which could be of translational benefit. SIGNIFICANCE STATEMENT: This work provides a mixed-effects model framework to quantify the effects of combination radiotherapy/DNA damage response pathway inhibitors/immune checkpoint inhibitors in preclinical tumor models and identify optimal dosage regimens, which could be of translational benefit.
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Affiliation(s)
- David Hodson
- Division of Pharmacy and Optometry, Faculty of Biology, Medicine, and Health, University of Manchester, Manchester, United Kingdom (D.H., H.M., L.A., K.O.); DMPK (S.G., J.Y.) and Biosciences (P.F., A.S.), Research and Early Development, Oncology R&D, AstraZeneca, Cambridge, United Kingdom; and DMPK, Research and Early Development, Neuroscience R&D, AstraZeneca, Cambridge, United Kingdom (M.D.)
| | - Hitesh Mistry
- Division of Pharmacy and Optometry, Faculty of Biology, Medicine, and Health, University of Manchester, Manchester, United Kingdom (D.H., H.M., L.A., K.O.); DMPK (S.G., J.Y.) and Biosciences (P.F., A.S.), Research and Early Development, Oncology R&D, AstraZeneca, Cambridge, United Kingdom; and DMPK, Research and Early Development, Neuroscience R&D, AstraZeneca, Cambridge, United Kingdom (M.D.)
| | - James Yates
- Division of Pharmacy and Optometry, Faculty of Biology, Medicine, and Health, University of Manchester, Manchester, United Kingdom (D.H., H.M., L.A., K.O.); DMPK (S.G., J.Y.) and Biosciences (P.F., A.S.), Research and Early Development, Oncology R&D, AstraZeneca, Cambridge, United Kingdom; and DMPK, Research and Early Development, Neuroscience R&D, AstraZeneca, Cambridge, United Kingdom (M.D.)
| | - Paul Farrington
- Division of Pharmacy and Optometry, Faculty of Biology, Medicine, and Health, University of Manchester, Manchester, United Kingdom (D.H., H.M., L.A., K.O.); DMPK (S.G., J.Y.) and Biosciences (P.F., A.S.), Research and Early Development, Oncology R&D, AstraZeneca, Cambridge, United Kingdom; and DMPK, Research and Early Development, Neuroscience R&D, AstraZeneca, Cambridge, United Kingdom (M.D.)
| | - Anna Staniszewska
- Division of Pharmacy and Optometry, Faculty of Biology, Medicine, and Health, University of Manchester, Manchester, United Kingdom (D.H., H.M., L.A., K.O.); DMPK (S.G., J.Y.) and Biosciences (P.F., A.S.), Research and Early Development, Oncology R&D, AstraZeneca, Cambridge, United Kingdom; and DMPK, Research and Early Development, Neuroscience R&D, AstraZeneca, Cambridge, United Kingdom (M.D.)
| | - Sofia Guzzetti
- Division of Pharmacy and Optometry, Faculty of Biology, Medicine, and Health, University of Manchester, Manchester, United Kingdom (D.H., H.M., L.A., K.O.); DMPK (S.G., J.Y.) and Biosciences (P.F., A.S.), Research and Early Development, Oncology R&D, AstraZeneca, Cambridge, United Kingdom; and DMPK, Research and Early Development, Neuroscience R&D, AstraZeneca, Cambridge, United Kingdom (M.D.)
| | - Michael Davies
- Division of Pharmacy and Optometry, Faculty of Biology, Medicine, and Health, University of Manchester, Manchester, United Kingdom (D.H., H.M., L.A., K.O.); DMPK (S.G., J.Y.) and Biosciences (P.F., A.S.), Research and Early Development, Oncology R&D, AstraZeneca, Cambridge, United Kingdom; and DMPK, Research and Early Development, Neuroscience R&D, AstraZeneca, Cambridge, United Kingdom (M.D.)
| | - Leon Aarons
- Division of Pharmacy and Optometry, Faculty of Biology, Medicine, and Health, University of Manchester, Manchester, United Kingdom (D.H., H.M., L.A., K.O.); DMPK (S.G., J.Y.) and Biosciences (P.F., A.S.), Research and Early Development, Oncology R&D, AstraZeneca, Cambridge, United Kingdom; and DMPK, Research and Early Development, Neuroscience R&D, AstraZeneca, Cambridge, United Kingdom (M.D.)
| | - Kayode Ogungbenro
- Division of Pharmacy and Optometry, Faculty of Biology, Medicine, and Health, University of Manchester, Manchester, United Kingdom (D.H., H.M., L.A., K.O.); DMPK (S.G., J.Y.) and Biosciences (P.F., A.S.), Research and Early Development, Oncology R&D, AstraZeneca, Cambridge, United Kingdom; and DMPK, Research and Early Development, Neuroscience R&D, AstraZeneca, Cambridge, United Kingdom (M.D.)
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Guzzetti S, Morentin Gutierrez P. An integrated modelling approach for targeted degradation: insights on optimization, data requirements and PKPD predictions from semi- or fully-mechanistic models and exact steady state solutions. J Pharmacokinet Pharmacodyn 2023; 50:327-349. [PMID: 37120680 PMCID: PMC10460745 DOI: 10.1007/s10928-023-09857-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Accepted: 03/28/2023] [Indexed: 05/01/2023]
Abstract
The value of an integrated mathematical modelling approach for protein degraders which combines the benefits of traditional turnover models and fully mechanistic models is presented. Firstly, we show how exact solutions of the mechanistic models of monovalent and bivalent degraders can provide insight on the role of each system parameter in driving the pharmacological response. We show how on/off binding rates and degradation rates are related to potency and maximal effect of monovalent degraders, and how such relationship can be used to suggest a compound optimization strategy. Even convoluted exact steady state solutions for bivalent degraders provide insight on the type of observations required to ensure the predictive capacity of a mechanistic approach. Specifically for PROTACs, the structure of the exact steady state solution suggests that the total remaining target at steady state, which is easily accessible experimentally, is insufficient to reconstruct the state of the whole system at equilibrium and observations on different species (such as binary/ternary complexes) are necessary. Secondly, global sensitivity analysis of fully mechanistic models for PROTACs suggests that both target and ligase baselines (actually, their ratio) are the major sources of variability in the response of non-cooperative systems, which speaks to the importance of characterizing their distribution in the target patient population. Finally, we propose a pragmatic modelling approach which incorporates the insights generated with fully mechanistic models into simpler turnover models to improve their predictive ability, hence enabling acceleration of drug discovery programs and increased probability of success in the clinic.
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Affiliation(s)
- Sofia Guzzetti
- DMPK, Research and Early Development, Oncology R&D, AstraZeneca, Cambridge, UK
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Abstract
Abstract:Long-term regulation of beat-to-beat variability involves several different kinds of controls. A linear approach performed by parametric models enhances the short-term regulation of the autonomic nervous system. Some non-linear long-term regulation can be assessed by the chaotic deterministic approach applied to the beat-to-beat variability of the discrete RR-interval series, extracted from the ECG. For chaotic deterministic systems, trajectories of the state vector describe a strange attractor characterized by a fractal of dimension D. Signals are supposed to be generated by a deterministic and finite dimensional but non-linear dynamic system with trajectories in a multi-dimensional space-state. We estimated the fractal dimension through the Grassberger and Procaccia algorithm and Self-Similarity approaches of the 24-h heart-rate variability (HRV) signal in different physiological and pathological conditions such as severe heart failure, or after heart transplantation. State-space representations through Return Maps are also obtained. Differences between physiological and pathological cases have been assessed and generally a decrease in the system complexity is correlated to pathological conditions.
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Ferrario M, Moissl U, Garzotto F, Cruz D, Tetta C, Signorini M, Ronco C, Grassmann A, Cerutti S, Guzzetti S. Low Frequency Oscillations of Heart Rate Variability and Central Volume. Auton Neurosci 2015. [DOI: 10.1016/j.autneu.2015.07.081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Colombo R, Raimondi F, Rech R, Castelli A, Fossali T, Marchi A, Borghi B, Corona A, Guzzetti S. Surgical Pleth Index guided analgesia blunts the intraoperative sympathetic response to laparoscopic cholecystectomy. Minerva Anestesiol 2015; 81:837-845. [PMID: 25375311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
BACKGROUND Surgical noxious stimuli generate a stress response with an increased sympathetic activity, potentially affecting the perioperative outcome. Surgical Pleth Index (SPI), derived from the pulse plethysmogram, has been proposed as a tool to assess nociception-antinociception balance. The relationship between SPI and autonomic nervous system (ANS) during general anesthesia is poorly understood and it is doubtful if SPI-guided analgesia may offer advantages over the standard clinical practice. The study was designed to evaluate if SPI-guided analgesia leads to a lower sympathetic modulation compared with standard clinical practice. METHODS Electrocardiographic wave, non-invasive blood pressure and SPI were recorded in ASA I-II patients undergoing elective laparoscopic cholecystectomy, randomized to receive SPI-guided analgesia or standard analgesia. Hemodynamic parameters, SPI, mean and variance of heart rate, low (LF) and high frequency (HF) spectral components of heart rate variability were measured at four time points: (T0) baseline, (T1) after induction of general anesthesia, (T2) after pneumoperitoneum insufflation and (T3) after pneumoperitoneum withdrawal. RESULTS SPI, hemodynamic and ANS parameters changed significantly in both groups during the study period (P<0.0001). At T2 SPI and markers of sympathetic modulation were significantly lower in SPI group (mean [SD] SPI 38.1 [15.3] vs. 48.1 [16.2] normalized units, P<0.05; LF 38 [8.6] vs. 56.2 [20.6] normalized units, P<0.01; LF/HF 1.01 [1.1] vs. 2.68 [2.07], P<0.01). There was no difference in remifentanil consumption, recovery time from anesthesia, or postoperative pain and complications. CONCLUSION SPI-guided analgesia led to a more stable sympathetic modulation but didn't seem to offer clinically relevant advantages over the standard clinical practice for laparoscopic cholecystectomy.
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Affiliation(s)
- R Colombo
- Anesthesiology and Intensive Care Unit, Azienda Ospedaliera Luigi Sacco, Polo Universitario, University of Milan, Milan, Italy -
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Raimondi F, Colombo R, Spazzolini A, Corona A, Castelli A, Rech R, Borghi B, Fossali T, Guzzetti S. Preoperative autonomic nervous system analysis may stratify the risk of hypotension after spinal anesthesia. Minerva Anestesiol 2015; 81:713-722. [PMID: 25384690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
BACKGROUND Studies on pregnant women undergoing cesarean delivery or elderly men scheduled for prostate brachytherapy have demonstrated the predictive value of heart rate variability (HRV) analysis for hypotension during spinal anesthesia. We conducted a prospective observational study to investigate if preoperative HRV analysis may have a role in identifying the risk of hypotension following spinal anesthesia in otherwise healthy patients. METHODS The study investigated 47 ASA physical status I-II patients aged between 18-50 years that underwent subarachnoid anesthesia for lower abdominal or orthopedic scheduled surgery. ECG was recorded from all subjects before the subarachnoid block. We analysed the autonomic nervous system modulation, measured by HRV analysis. The variables that were be considered were preoperative HRV total power, low frequency (LF) and high frequency (HF) heart beat oscillations and LF/HF ratio. The LF/HF ratio was dichotomized according to the median for sensitivity analysis. The lowest arterial pressure value between spinal anesthesia and the end of surgery was recorded. RESULTS The median LF/HF before anesthesia was 2.3. We considered two groups of 23 (LF/HF<2.3, group LOW) and 24 (LF/HF>2.3, group HIGH) patients respectively. Both groups had similar baseline demographic and hemodynamic variables. A high preoperative sympathetic outflow and loss of vagal modulation, as stated by LF/HF>2.3, was correlated with a relative risk of 7.7 (95%CI 1.04 to 56.6, p=0.023) of post-spinal hypotension. CONCLUSIONS Preoperative analysis of autonomic nervous system modulation might be useful to stratify the risk of post-spinal hypotension and it might indicate the need for careful monitoring or prophylactic fluids.
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Affiliation(s)
- F Raimondi
- Anesthesiology and Intensive Care Unit, Luigi Sacco Hospital, Polo Universitario of the University of Milan, Milan, Italy -
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Guzzetti S, Bassani T, Latini R, Masson S, Barlera S, Citerio G, Porta A. Autonomic cardiovascular modulation with three different anesthetic strategies during neurosurgical procedures. Minerva Anestesiol 2015; 81:3-11. [PMID: 24824955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
BACKGROUND Autonomic cardiovascular modulation during surgery might be affected by different anesthetic strategies. Aim of the present study was to assess autonomic control during three different anesthetic strategies in the course of neurosurgical procedures by the linear and non-linear analysis of two cardiovascular signals. METHODS Heart rate (EKG-RR intervals) and systolic arterial pressure (SAP) signals were analyzed in 93 patients during elective neurosurgical procedures at fixed points: anesthetic induction, dura mater opening, first and second hour of surgery, dura mater and skin closure. Patients were randomly assigned to three anesthetic strategies: sevoflurane+fentanyl (S-F), sevoflurane+remifentanil (S-R) and propofol+remifentanil (P-R). RESULTS All the three anesthetic strategies were characterized by a reduction of RR and SAP variability. A more active autonomic sympathetic modulation, as ratio of low to high frequency spectral components of RR variability (LF/HF), was present in the P-R group vs. S-R group. This is confirmed by non-linear symbolic analysis of RR series and SAP variability analysis. In addition, an increased parasympathetic modulation was suggested by symbolic analysis of RR series during the second hour of surgery in S-F group. CONCLUSION Despite an important reduction of cardiovascular signal variability, the analysis of RR and SAP signals were capable to detect information about autonomic control during anesthesia. Symbolic analysis (non-linear) seems to be able to highlight the differences of both the sympathetic (slow) and vagal (fast) modulation among anesthetics, while spectral analysis (linear) underlines the same differences but only in terms of balance between the two neural control systems.
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Affiliation(s)
- S Guzzetti
- Department of Emergency Medicine "Luigi Sacco" Hospital, Milan, Italy -
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Colombo R, Marchi A, Borghi B, Fossali T, Tobaldini E, Guzzetti S, Raimondi F. Influence of gravitational sympathetic stimulation on the Surgical Plethysmographic Index. Physiol Res 2014; 64:183-9. [PMID: 25317683 DOI: 10.33549/physiolres.932798] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Surgical Plethysmographic Index (SPI), calculated from pulse photo-plethysmographic amplitude oscillations, has been proposed as a tool to measure nociception anti-nociception balance during general anesthesia, but it is affected by several confounding factor that alter the autonomic nervous system (ANS) modulation. We hypothesized that SPI may be mainly affected by sympathetic stimulation independently from nociception. We studied the effects of two sympathetic stimuli on SPI, delivered through passive head-up tilt at 45 and 90 degrees angles, in nine awake healthy adults. The sympathetic modulation was assessed by means of heart rate variability (HRV) analysis. Mean (SD) SPI significantly increased from baseline to 45 degrees [from 38.6 (13.7) to 60.8 (7.6), p<0.001)] and to 90 degrees angle tilt [82.3 (5.4), p<0.001]. The electrocardiographic mean R-to-R interval significantly shortened during both passive tilts, whereas systolic arterial pressure did not change during the study protocol. HRV changed significantly during the study protocol towards a predominance of sympathetic modulation during passive tilt. Gravitational sympathetic stimulation at two increasing angles, in absence of any painful stimuli, affects SPI in awake healthy volunteers. SPI seems to reflect the sympathetic outflow directed to peripheral vessels.
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Affiliation(s)
- R Colombo
- Anesthesiology and Intensive Care Unit, Azienda Ospedaliera "L. Sacco", Milano, Italy.
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Villa P, Dominici R, Dolci A, Panteghini M, Guzzetti S. N-terminal proB-type natriuretic peptide testing: practical diagnostic value in a emergency department. Eur Heart J 2013. [DOI: 10.1093/eurheartj/eht307.p674] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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13
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Villa P, Dolci A, Dominici R, Panteghini M, Fundarò C, Guzzetti S. Diagnostic value of N-terminal ProB-Type Natriuretic Peptide in Emergency Department: Analysis by subgroups. Emerg Care J 2012. [DOI: 10.4081/ecj.2012.3.34] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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14
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Jensen RL, Abraham S, Hu N, Jensen RL, Boulay JL, Leu S, Frank S, Vassella E, Vajtai I, von Felten S, Taylor E, Schulz M, Hutter G, Sailer M, Hench J, Mariani L, van Thuijl HF, Scheinin I, van Essen DF, Heimans JJ, Wesseling P, Ylstra B, Reijneveld JC, Borges AR, Larrubia PL, Marques JMB, Cerdan SG, Brastianos P, Horowitz P, Santagata S, Jones RT, McKenna A, Getz G, Ligon K, Palescandolo E, Van Hummelen P, Stemmer-Rachamimov A, Louis D, Hahn WC, Dunn I, Beroukhim R, Guan X, Vengoechea J, Zheng S, Sloan A, Chen Y, Brat D, O'Neill BP, Cohen M, Aldape K, Rosenfeld S, Noushmehr H, Verhaak RG, Barnholtz-Sloan J, Bahassi EM, Li YQ, Cross E, Li W, Vijg J, McPherson C, Warnick R, Stambrook P, Rixe O, Manterola L, Tejada-Solis S, Diez-Valle R, Gonzalez M, Jauregui P, Sampron N, Barrena C, Ruiz I, Gallego J, Delattre JY, de Munain AL, Mlonso MM, Saito K, Mukasa A, Nagae G, Aihara K, Takayanagi S, Aburatani H, Saito N, Kong XT, Fu BD, Du S, Hasso AN, Linskey ME, Bota D, Li C, Chen YS, Chen ZP, Kim CH, Cheong JH, Kim JM, Yelon NP, Jacoby E, Cohen ZR, Ishida J, Kurozumi K, Ichikawa T, Onishi M, Fujii K, Shimazu Y, Date I, Narayanan R, Ho QH, Levin BS, Maeder ML, Joung JK, Nutt CL, Louis DN, Thorsteinsdottir J, Fu P, Gehrmann M, Multhoff G, Tonn JC, Schichor C, Thirumoorthy K, Gordon N, Walston S, Patel D, Okamoto M, Chakravarti A, Palanichamy K, French P, Erdem L, Gravendeel L, de Rooi J, Eilers P, Idbaih A, Spliet W, den Dunnen W, Teepen J, Wesseling P, Smitt PS, Kros JM, Gorlia T, van den Bent M, McCarthy D, Cook RW, Oelschlager K, Maetzold D, Hanna M, Wick W, Meisner C, Hentschel B, Platten M, Sabel MC, Koeppen S, Ketter R, Weiler M, Tabatabai G, Schilling A, von Deimling A, Gramatzki D, Westphal M, Schackert G, Loeffler M, Simon M, Reifenberger G, Weller M, Moren L, Johansson M, Bergenheim T, Antti H, Sulman EP, Goodman LD, Wani KM, DeMonte F, Aldape KD, Krischek B, Gugel I, Aref D, Marshall C, Croul S, Zadeh G, Nilsson CL, Sulman E, Liu H, Wild C, Lichti CF, Emmett MR, Lang FF, Conrad C, Alentorn A, Marie Y, Boisselier B, Carpetier C, Mokhtari K, Hoang-Xuan K, Capelle L, Delattre JY, Idbaih A, Lautenschlaeger T, Huebner A, McIntyre JB, Magliocco T, Chakravarti A, Hamilton M, Easaw J, Pollo B, Calatozzolo C, Vuono R, Guzzetti S, Eoli M, Silvani A, Di Meco F, Filippini G, Finocchiaro G, Joy A, Ramesh A, Smirnov I, Reiser M, Shapiro W, Mills G, Kim S, Feuerstein B, Gonda DD, Li J, McCabe N, Walker S, Goffard N, Wikstrom K, McLean E, Greenan C, Delaney T, McCarthy M, McDyer F, Keating KE, James IF, Harrison T, Mullan P, Harkin DP, Carter BS, Kennedy RD, Chen CC, Patel AS, Allen JE, Dicker DT, Rizzo K, Sheehan JM, Glantz MJ, El-Deiry WS, Salhia B, Ross JT, Kiefer J, Van Cott C, Metpally R, Baker A, Sibenaller Z, Nasser S, Ryken T, Ramanathan R, Berens ME, Carpten J, Tran NL, Bi Y, Pal S, Zhang Z, Gupta R, Macyszyn L, Fetting H, O'Rourke D, Davuluri RV, Ezrin AM, Moore K, Stummer W, Hadjipanayis CG, Cahill DP, Beiko J, Suki D, Prabhu S, Weinberg J, Lang F, Sawaya R, Rao G, McCutcheon I, Barker FG, Aldape KD, Trister AD, Bot B, Fontes K, Bridge C, Baldock AL, Rockhill JK, Mrugala MM, Rockne RR, Huang E, Swanson KR, Underhill HR, Zhang J, Shi M, Lin X, Mikheev A, Rostomily RC, Scheck AC, Stafford P, Hughes A, Cichacz Z, Coons SW, Johnston SA, Mainwaring L, Horowitz P, Craig J, Garcia D, Bergthold G, Burns M, Rich B, Ramkissoon S, Santagata S, Eberhart C, Ligon A, Goumnerova L, Stiles C, Kieran M, Hahn W, Beroukhim R, Ligon K, Ramkissoon S, Olausson KH, Correia J, Gafni E, Liu H, Theisen M, Craig J, Hayashi M, Haidar S, Maire C, Mainwaring LA, Burns M, Norden A, Wen P, Stiles C, Ligon A, Kung A, Alexander B, Tonellato P, Ligon KL. LAB-OMICS AND PROGNOSTIC MARKERS. Neuro Oncol 2012. [DOI: 10.1093/neuonc/nos231] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Colombo R, Corona A, Guzzetti S, Raimondi F. Can we study Saturn's rings through binoculars? Minerva Anestesiol 2012; 78:626-627. [PMID: 22410470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
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Porta A, Bassani T, Bari V, Pinna GD, Maestri R, Guzzetti S. Accounting for Respiration is Necessary to Reliably Infer Granger Causality From Cardiovascular Variability Series. IEEE Trans Biomed Eng 2012; 59:832-41. [DOI: 10.1109/tbme.2011.2180379] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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17
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Joshi K, Gupta S, Mazumder S, Okemoto Y, Angenieux B, Kornblum H, Nakano I, Synowitz M, Kumar J, Petrosino S, Imperatore R, Smith E, Wendt P, Erdmann B, Nuber U, Nuber U, Matiash V, Chirasani S, Cristino L, DiMarzo V, Kettenmann H, Glass R, Soroceanu L, Matlaf L, Cobbs C, Kim YW, Kim SH, Kwon C, Han DY, Kim EH, Chang JH, Liu JL, Kim YH, Kim S, Long PM, Viapiano MS, Jaworski DM, Kanemura Y, Shofuda T, Kanematsu D, Matsumoto Y, Yamamoto A, Nonaka M, Moriuchi S, Nakajima S, Suemizu H, Nakamura M, Okada Y, Okano H, Yamasaki M, Price RL, Song J, Bingmer K, Zimmerman P, Rivera A, Yi JY, Cook C, Chiocca EA, Kwon CH, Kang SG, Shin HD, Mok HS, Park NR, Sim JK, Shin HJ, Park YK, Jeun SS, Hong YK, Lang FF, McKenzie BA, Zemp FJ, Lun X, Narendran A, McFadden G, Kurz E, Forsyth P, Talsma CE, Flack CG, Zhu T, He X, Soules M, Heth JA, Muraszko K, Fan X, Chen L, Guerrero-Cazares H, Noiman L, Smith C, Beltran N, Levchenko A, Quinones-Hinojosa A, Peruzzi P, Godlewski J, Lawler SE, Chiocca EA, Sarkar S, Doring A, Lun X, Wang X, Kelly J, Hader W, Dunn JF, Kinniburgh D, Robbins S, Forsyth P, Cairncross G, Weiss S, Yong VW, Vollmann-Zwerenz A, Velez-Char N, Jachnik B, Ramm P, Leukel P, Bogdahn U, Hau P, Kim SH, Lee MK, Chwae YJ, Yoo BC, Kim KH, Kristoffersen K, Stockhausen MT, Poulsen HS, Kaluzova M, Machaidze R, Wankhede M, Hadjipanayis CG, Romane AM, Sim FJ, Wang S, Chandler-Militello D, Li X, Al Fanek Y, Walter K, Johnson M, Achanta P, Quinones-Hinojosa A, Goldman SA, Shinojima N, Hossain A, Takezaki T, Gumin J, Gao F, Nwajei F, Cheung V, Figueroa J, Lang FF, Pellegatta S, Orzan F, Anghileri E, Guzzetti S, Porrati P, Eoli M, Finocchiaro G, Fu J, Koul D, Wang S, Yao J, Gumin JG, Sulman E, Lang F, Aldape KK, Colman H, Yung AW, Koul D, Fu J, Yao J, Wang S, Gumin J, Sulman E, Lang F, Aldape K, Colman H, Yung AW, Alonso MM, Manterola L, urquiza L, Cortes-Santiago N, Diez-Valle R, Tejada-Solis S, Garcia-foncillas J, Fueyo J, Gomez-Manzano C, Nguyen S, Stechishin O, Luchman A, Weiss S, Lathia JD, Gallagher J, Li M, Myers J, Hjelmeland A, Huang A, Rich J, Bhat K, Vaillant B, Balasubramaniyan V, Ezhilarasan R, Sulman E, Colman H, Aldape K, Lathia JD, Hitomi M, Gallagher J, Gadani S, Li M, Adkins J, Vasanji A, Wu Q, Soeda A, McLendon R, Chenn A, Hjelmeland A, Park D, Rich J, Yao J, Fu J, Koul D, Weinstein JN, Alfred Yung WK, Zagzag D, Esencay M, Klopsis D, Liu M, Narayana A, Parker E, Golfinos J, Clark PA, Kandela IK, Weichert JP, Kuo JS, Fouse SD, Nagarajan RP, Nakamura J, James CD, Chang S, Costello JF, Gong X, Kankar G, Di K, Reeves A, Linskey M, Bota DA, Schmid RS, Bash RE, Vitucci M, Werneke AM, Miller CR, Kim E, Kim M, Kim K, Lee J, Du F, Li P, Wechsler-Reya R, Yang ZJ. STEM CELLS. Neuro Oncol 2011. [DOI: 10.1093/neuonc/nor163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Tasdemiroglu E, Kaya M, Yildirim CH, Lucas KG, Bao L, Bruggeman R, Specht C, Murray JC, Donahue DJ, Galliani CA, Blondin NA, Hui P, Vortmeyer A, Hasbani J, Baehring J, Jensen RL, Lee J, Lake WB, Baskaya MK, Salamat MS, Kennedy T, Abraham S, Jensen RL, Lusis EA, Scheithauer B, Yachnis AT, Chicoine MR, Paulus W, Perry A, Chan DT, Kam MK, Ma BB, Ng SC, Siu DY, Ng HK, Poon WS, Dunbar EM, Dong HJ, Liu C, Chi YY, Keeling C, Yachnis AT, Stephen JH, Sievert AJ, Resnick AC, Storm PB, Judkins AR, Santi M, Kirsch M, Stelling A, Koch E, Salzer R, Schackert G, Steiner G, Pollo B, Maderna E, Valletta L, Guzzetti S, Eoli M, Calatozzolo C, Nunziata R, Salmaggi A, Finocchiaro G, Kastenhuber ER, Campos C, Brennan CW, Mellinghoff IK, Huse JT, Zhang H, Sergey M, Estrada DK, Kay AB, Wagner AS, Khanlou N, Vinters HV, Cloughesy TF, Yong WH. Pathology. Neuro Oncol 2010. [DOI: 10.1093/neuonc/noq116.s10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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19
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Valletta L, Guzzetti S, Di Stefano A, Maderna E, Pollo B, Finocchiaro G, Eoli M. PP64 Prognostic relevance of isocitrate dehydrogenase I and II mutations and MGMT promoter hypermethylation in diffuse astrocytomas. EJC Suppl 2009. [DOI: 10.1016/s1359-6349(09)72218-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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20
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Calcagno E, Canetta A, Guzzetti S, Cervo L, Invernizzi RW. Strain differences in basal and post-citalopram extracellular 5-HT in the mouse medial prefrontal cortex and dorsal hippocampus: relation with tryptophan hydroxylase-2 activity. J Neurochem 2007; 103:1111-20. [PMID: 17666043 DOI: 10.1111/j.1471-4159.2007.04806.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We used the microdialysis technique to compare basal extracellular serotonin (5-HT) and the response to citalopram in different strains of mice with functionally different allelic forms of tryptophan hydroxylase-2 (TPH-2), the rate-limiting enzyme in brain 5-HT synthesis. DBA/2J, DBA/2N and BALB/c mice carrying the 1473G allele of TPH-2 had less dialysate 5-HT in the medial prefrontal cortex and dorsal hippocampus (DH) (20-40% reduction) than C57BL/6J and C57BL/6N mice carrying the 1473C allele. Extracellular 5-HT estimated by the zero-net flux method confirmed the result of conventional microdialysis. Citalopram, 1.25, 5 and 20 mg/kg, dose-dependently raised extracellular 5-HT in the medial prefrontal cortex of C57BL/6J mice, with maximum effect at 5 mg/kg, but had significantly less effect in DBA/2J and BALB/c mice and in the DH of DBA/2J mice. A tryptophan (TRP) load enhanced basal extracellular 5-HT in the medial prefrontal cortex of DBA/2J mice but did not affect citalopram's ability to raise cortical and hippocampal extracellular 5-HT. The impairment of 5-HT synthesis quite likely accounts for the reduction of basal 5-HT and the citalopram-induced rise in mice carrying the mutated enzyme. These findings might explain why DBA/2 and BALB/c mice do not respond to citalopram in the forced swimming test. Although TRP could be a useful strategy to improve the antidepressant effect of citalopram (Cervo et al. 2005), particularly in subjects with low 5-HT synthesis, the contribution of serotonergic and non-serotonergic mechanisms to TRP's effect remains to be elucidated.
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Affiliation(s)
- E Calcagno
- Laboratory of Neurochemistry and Behavior, Department of Neuroscience, Istituto di Ricerche Farmacologiche Mario Negri, Milan, Italy
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Porta A, Faes L, Masé M, D'Addio G, Pinna GD, Maestri R, Montano N, Furlan R, Guzzetti S, Nollo G, Malliani A. An integrated approach based on uniform quantization for the evaluation of complexity of short-term heart period variability: Application to 24 h Holter recordings in healthy and heart failure humans. Chaos 2007; 17:015117. [PMID: 17411274 DOI: 10.1063/1.2404630] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
We propose an integrated approach based on uniform quantization over a small number of levels for the evaluation and characterization of complexity of a process. This approach integrates information-domain analysis based on entropy rate, local nonlinear prediction, and pattern classification based on symbolic analysis. Normalized and non-normalized indexes quantifying complexity over short data sequences ( approximately 300 samples) are derived. This approach provides a rule for deciding the optimal length of the patterns that may be worth considering and some suggestions about possible strategies to group patterns into a smaller number of families. The approach is applied to 24 h Holter recordings of heart period variability derived from 12 normal (NO) subjects and 13 heart failure (HF) patients. We found that: (i) in NO subjects the normalized indexes suggest a larger complexity during the nighttime than during the daytime; (ii) this difference may be lost if non-normalized indexes are utilized; (iii) the circadian pattern in the normalized indexes is lost in HF patients; (iv) in HF patients the loss of the day-night variation in the normalized indexes is related to a tendency of complexity to increase during the daytime and to decrease during the nighttime; (v) the most likely length L of the most informative patterns ranges from 2 to 4; (vi) in NO subjects classification of patterns with L=3 indicates that stable patterns (i.e., those with no variations) are more present during the daytime, while highly variable patterns (i.e., those with two unlike variations) are more frequent during the nighttime; (vii) during the daytime in HF patients, the percentage of highly variable patterns increases with respect to NO subjects, while during the nighttime, the percentage of patterns with one or two like variations decreases.
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Affiliation(s)
- A Porta
- Dipartimento di Scienze Precliniche, LITA di Vialba, Universita' degli Studi di Milano, Laboratorio di Modellistica di Sistemi Complessi, Via G.B. Grassi 74, 20157, Milan, Italy.
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Affiliation(s)
- C. Chiccoli
- a INFN Sezione di Bologna , Via Irnerio 46, 40126 , Bologna , Italy
| | - S. Guzzetti
- b Dip.to di Chimica Fisica ed Inorganica Universitá , Viale Risorgimento 4, 40136 , Bologna , Italy
| | - P. Pasini
- a INFN Sezione di Bologna , Via Irnerio 46, 40126 , Bologna , Italy
| | - C. Zannoni
- b Dip.to di Chimica Fisica ed Inorganica Universitá , Viale Risorgimento 4, 40136 , Bologna , Italy
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Porta A, Montano N, Furlan R, Cogliati C, Guzzetti S, Gnecchi-Ruscone T, Malliani A, Chang HS, Staras K, Gilbey MP. Automatic classification of interference patterns in driven event series: application to single sympathetic neuron discharge forced by mechanical ventilation. Biol Cybern 2004; 91:258-273. [PMID: 15378378 DOI: 10.1007/s00422-004-0513-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2003] [Accepted: 07/22/2004] [Indexed: 05/24/2023]
Abstract
This study proposes a method for the automatic classification of nonlinear interactions between a strictly periodical event series modelling the activity of an exogenous oscillator working at a fixed and well-known rate and an event series modelling the activity of a self-sustained oscillator forced by the exogenous one. The method is based on a combination of several well-known tools (probability density function of the cyclic relative phase, probability density function of the count of forced events per forcing cycle, conditional entropy of the cyclic relative phase sequence and a surrogate data approach). Classification is reached via a sequence of easily applicable decision rules, thus rendering classification virtually user-independent and fully reproducible. The method classifies four types of dynamics: full uncoupling, quasiperiodicity, phase locking and aperiodicity. In the case of phase locking, the coupling ratio (i.e. n: m) and the strength of the coupling are calculated. The method, validated on simulations of simple and complex phase-locking dynamics corrupted by different levels of noise, is applied to data derived from one anesthetized and artificially ventilated rat to classify the nonlinear interactions between mechanical ventilation and: (1) the discharges of two (contemporaneously recorded) single postganglionic sympathetic neurons innervating the caudal ventral artery in the tail and (2) arterial blood pressure. Under central apnea, the activity of the underlying sympathetic oscillators is perturbed by means of five different lung inflation rates (0.58, 0.64, 0.76, 0.95, 1.99 Hz). While ventilation and arterial pressure are fully uncoupled, ventilation is capable of phase locking sympathetic discharges, thus producing 40% of phase-locked patterns (one case of 2:5, 1:1, 3:2 and 2:2) and 40% of aperiodic dynamics. In the case of phase-locked patterns, the coupling strength is low, thus demonstrating that this pattern is sliding. Non-stationary interactions are observed in 20% of cases. The two discharges behave differently, suggesting the presence of a population of sympathetic oscillators working at different frequencies.
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Affiliation(s)
- A Porta
- Universita' degli Studi di Milano, Dipartimento di Scienze Precliniche, LITA di Vialba, Via G.B. Grassi 74, 20157 Milan, Italy.
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24
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Porta A, Guzzetti S, Montano N, Furlan R, Pagani M, Malliani A, Cerutti S. Entropy, entropy rate, and pattern classification as tools to typify complexity in short heart period variability series. IEEE Trans Biomed Eng 2001; 48:1282-91. [PMID: 11686627 DOI: 10.1109/10.959324] [Citation(s) in RCA: 271] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
An integrated approach to the complexity analysis of short heart period variability series (approximately 300 cardiac beats) is proposed and applied to healthy subjects during the sympathetic activation induced by head-up tilt and during the driving action produced by controlled respiration (10, 15, and 20 breaths/min, CR10, CR15, and CR20 respectively). The approach relies on: 1) the calculation of Shannon entropy (SE) of the distribution of patterns lasting three beats; 2) the calculation of a regularity index based on an entropy rate (i.e., the conditional entropy); 3) the classification of frequent deterministic patterns (FDPs) lasting three beats. A redundancy reduction criterion is proposed to group FDPs in four categories according to the number and type or of heart period changes: a) no variation (0V); b) one variation (1V); and c) two like variations (2LV); 4) two unlike variations (2UV). We found that: 1) the SE decreased during tilt due to the increased percentage of missing patterns; 2) the regularity index increased during tilt and CR10 as patterns followed each other according to a more repetitive scheme; and 3) during CR10, SE and regularity index were not redundant as the regularity index significantly decreased while SE remained unchanged. Concerning pattern analysis we found that: a) at rest mainly three classes (0V, 1V, and 2LV) were detected; b) 0V patterns were more likely during tilt; c) 1V and 2LV patterns were more frequent during CR10; and d) 2UV patterns were more likely during CR20. The proposed approach based on quantification of complexity allows a full characterization of heart period dynamics and the identification of experimental conditions known to differently perturb cardiovascular regulation.
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Affiliation(s)
- A Porta
- Dipartimento di Scienze Precliniche, Universita' degli Studi di Milano, LITA di Vialba, Italy.
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Abstract
The analysis of heart rate variability (HRV) provides information about autonomic cardiovascular control in healthy subjects. In the past 15 years, several articles have been published regarding HRV and chronic heart failure (CHF). The results of these papers substantially demonstrated that HRV is significantly different in CHF patients compared to controls. Moreover, some variables derived from HRV analysis showed significant independent prognostic capacity. In particular, the reduction of variance (expressed as SDNN) and low-frequency spectral component of HRV (ranging from 0.03 to 0.15 Hz) seem related to an increased mortality in CHF. Nevertheless, these variables are not yet considered in clinical practice. A better understanding of the physiopathological basis of the reported alterations of HRV in CHF patients is required in order to permit its use as a clinical tool for prognosis and tailored therapy in individual CHF patients.
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Affiliation(s)
- S Guzzetti
- Centro Ricerche Cardiovascolari, Università di Milano, Italy.
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Guzzetti S. [Heart rate variability]. Ital Heart J Suppl 2001; 2:450-4. [PMID: 11388327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
In 1981 a study on heart rate variability (HRV) and on the neural control of the heart was published in Science. Since then, the number of papers concerning this topic has increased exponentially. Some aspects of the relationship between HRV and the neural control of the cardiovascular system are now clear, for example: a decreased SDNN (a measure of variance) during a period of 24 hours is a well established independent negative prognostic factor after acute myocardial infarction and in chronic heart failure patients. Moreover, an increased sympathetic modulation elicited by standard laboratory maneuvers determines an increased power of the low frequency (LF) spectral component (0.03-0.15 Hz), expressed in normalized units. Nevertheless, the interpretation of the oscillatory components present in HRV, particularly in pathophysiological conditions, is far from being clear. The influence of several neurohumoral circuits can induce various changes in HRV according to different physiological or pathological conditions. A new approach to the study of HRV called "information domain" might help to obtain some more information about HRV. Furthermore, in the future, HRV analysis might be useful when deciding on the best pharmacological combination for the individual patient and for the probabilistic prediction of acute cardiac events.
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Affiliation(s)
- S Guzzetti
- Medicina Interna II, Università degli Studi, Ospedale L. Sacco, Milano.
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Guzzetti S, Mezzetti S, Magatelli R, Porta A, De Angelis G, Rovelli G, Malliani A. Linear and non-linear 24 h heart rate variability in chronic heart failure. Auton Neurosci 2000; 86:114-9. [PMID: 11269916 DOI: 10.1016/s1566-0702(00)00239-3] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
It has recently been demonstrated that SDNN of heart rate variability (HRV) is a useful independent prognostic tool in chronic heart failure (CHF). The purpose of the present study was to evaluate if spectral and non-linear analysis of 24-h HRV, considered markers of autonomic cardiac modulation, contain independent prognostic information in CHF patients. Twenty normal subjects and thirty consecutive outpatients with clinically stable CHF were studied for 2 years. Periods of 300 R-R intervals were analyzed from Holter recordings. The power spectral analysis, the slope of the linear relationship between log-power versus log-frequency (1/f), and the complexity content (using corrected conditional entropy; CCE) of the R-R series were calculated. The normalized power of the low frequency spectral component (LF) and the 1/f slope were significantly lower in patients compared to controls (respectively 30.1 +/- 3.0 vs. 48.6 +/- 3.4 and -1.27 +/- 0.04 vs. -1.08 +/- 0.05; P < 0.05). Moreover, the patients who died during the study presented a reduced LF (20.9 +/- 4.1 vs. 35.5 +/- 3.5 nu; P < 0.05) and a steeper 1/f slope (-1.40 +/- 0.09 vs. -1.21 +/- 0.04 nuts, P < 0.05) compared to survivors. These results remained significant in a logistic model including heart rate and SDNN. The information content present in spectral and non-linear analysis of HRV in CHF patients has prognostic relevance independently from the time domain measures of HRV. In particular, the reduction of LF power seems the best indicator among those considered.
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Affiliation(s)
- S Guzzetti
- Centro Ricerche Cardiovascolari, CNR, Dipartimento Scienze Precliniche L.I.T.A. Vialba, Medicina Interna II, Ospedale L. Sacco, Universita degli Studi, Via GB Grassi 74, 20157 Milan, Italy.
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Porta A, Baselli G, Guzzetti S, Pagani M, Malliani A, Cerutti S. Prediction of short cardiovascular variability signals based on conditional distribution. IEEE Trans Biomed Eng 2000; 47:1555-64. [PMID: 11125590 DOI: 10.1109/10.887936] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
A new approach measuring the predictability of a process is proposed. The predictor is defined as the median of the distribution conditioned by a sequence of L - 1 previous samples (i.e., a pattern). A function referred to as the corrected mean squared predictor error is defined to prevent the perfect adequacy to the data (i.e., the decrease to zero of the prediction error), thus avoiding to divide the whole set of data in learning and test sets. This function exhibits a minimum and this minimum is taken as a measure of predictability of the series. The use of the minimization procedure avoids to fix a priori the pattern length L. This approach permits one a reliable measure of predictability on short data sequences (around 300 samples). Moreover, this method, in connection with a surrogate data approach, is useful to detect nonlinear dynamics. The analysis indicates that, in simulated and real data, predictability and nonlinearity measures provide different information. The application of this approach to the analysis of cardiovascular variability series of the heart period (RR interval) and systolic arterial pressure (SAP) shows: 1) SAP series is more predictable than RR interval series; 2) predictability of the RR interval series is larger during tilt, during controlled respiration at 10 breaths/min (bpm) and after high-dose administration of atropine; 3) SAP series is dominated by linear correlation; 4) RR interval series exhibits nonlinear dynamics during controlled respiration at 10 bpm and after low-dose administration of atropine, while it is linear during sympathetic activation produced by tilt and after peripheral parasympathetic blockade caused by high-dose administration of atropine.
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Affiliation(s)
- A Porta
- Dipartimento di Scienze Precliniche, Università degli Studi di Milano, LITA di Vialba, Milan, Italy.
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Dalla Vecchia L, Storti T, Cogliati C, Guzzetti S, Danna P, Scrofani R, Di Biasi P, Malliani A. Comparison of low-dose dobutamine ventriculography with low-dose dobutamine echocardiography for predicting regional improvement in left ventricular function after coronary artery bypass grafting. Am J Cardiol 2000; 86:371-4. [PMID: 10946026 DOI: 10.1016/s0002-9149(00)00948-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The demonstration of a contractile reserve during low-dose dobutamine echocardiography (LDDE) identifies viable myocardium and predicts recovery of left ventricular (LV) function after myocardial revascularization in patients with chronic coronary artery disease. However, a technically difficult transthoracic visualization may limit the use of LDDE, thus requiring an alternative diagnostic procedure. The present study compares LDDE with low-dose dobutamine ventriculography (LDDV) in predicting an improvement in regional LV function after surgical revascularization. We studied 18 patients with coronary artery disease and LV dysfunction who were to undergo coronary artery bypass grafting. Preoperatively, all patients were evaluated for the presence of viable myocardium using LDDE and LDDV. Follow-up echocardiography at rest and left ventriculography were performed 4 months after successful revascularization to assess recovery of LV function. The sensitivity and specificity of LDDE to identify dysfunctional segments capable of recovering function were 63% and 71%, respectively, with a diagnostic accuracy of 68%. The sensitivity, specificity, and diagnostic accuracy of LDDE improved to 81%, 72%, and 76% when patients with optimal transthoracic evaluation were selected, whereas they were 30%, 77%, and 57%, respectively, in those who underwent suboptimal evaluation. The sensitivity, specificity, and diagnostic accuracy of LDDV were 66%, 75%, and 71%, respectively, with no difference in subgroups of patients. This study demonstrates that LDDV can be considered a useful technique for identifying the presence of myocardial viability and may provide an advantage over LDDE in patients with suboptimal echocardiographic visualization.
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Guzzetti S, Mayet J, Shahi M, Mezzetti S, Foale RA, Sever PS, Poulter NR, Porta A, Malliani A, Thom SA. Absence of sympathetic overactivity in Afro-Caribbean hypertensive subjects studied by heart rate variability. J Hum Hypertens 2000; 14:337-42. [PMID: 10822322 DOI: 10.1038/sj.jhh.1001009] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Black hypertensives present a greater prevalence of left ventricular hypertrophy and an increased mortality compared to white hypertensives. Differences in sympathetic activity might contribute to explain these racial differences in hypertension. Nevertheless, previous laboratory studies did not show any increase of sympathetic activity direct to the heart in black subjects. The aim of the present study was to investigate the cardiac sympatho-vagal balance in black and white hypertensives analysing heart rate variability, during the entire 24 h. We analysed Holter recordings of 52 essential hypertensive patients, who had never received antihypertensive treatment, 26 of whom were black and 26 were white. Consecutive series of 300 beats, with 150 beats overlapped (approximately 600 series/day), were considered for the analysis in time and frequency domain. The mean 24-h value of the power of the low frequency spectral component (0.04-0.15 Hz), expressed in normalised units, ie a marker of sympathetic modulation, was significantly lower in the group of black patients compared to whites (respectively 40.0 +/- 2.1 vs 53.6 +/- 3.6 nu, P < 0.01). Similar results were observed for the LF/HF ratio, an index of the sympatho-vagal balance (respectively 4.11 +/- 0.58 vs 5.98 +/- 0.79; P < 0.05). In a multiple linear regression analysis, considering diastolic blood pressure, left ventricular mass index, race and age as independent variables, only race (P < 0.002) and age (P < 0.01) could independently predict the normalised low frequency power or the LF/HF ratio, as dependent variables. The results of this study suggest some blunting of the cardiac sympathetic neural modulation in black hypertensives compared to white hypertensives, during the entire 24 h.
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Affiliation(s)
- S Guzzetti
- Centro Ricerche Cardiovascolari, CNR, Medicina Interna II, Ospedale 'L. Sacco', Dipartimento Scienze Precliniche L.I.T.A. Vialba, Universita' Studi di Milano, Italy
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Porta A, Guzzetti S, Montano N, Pagani M, Somers V, Malliani A, Baselli G, Cerutti S. Information domain analysis of cardiovascular variability signals: evaluation of regularity, synchronisation and co-ordination. Med Biol Eng Comput 2000; 38:180-8. [PMID: 10829411 DOI: 10.1007/bf02344774] [Citation(s) in RCA: 130] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
A unifying general approach to measure regularity, synchronisation and co-ordination is proposed. This approach is based on conditional entropy and is specifically designed to deal with a small amount of data (a few hundred samples). Quantitative and reliable indexes of regularity, synchronisation and co-ordination (ranging from 0 to 1) are derived in a domain (i.e. the information domain) different from time and frequency domains. The method is applied to evaluate regularity, synchronisation and co-ordination among cardiovascular beat-to-beat variability signals during sympathetic activation induced by head-up tilt (T), during the perturbing action produced by controlled respiration at 10, 15 and 20 breaths/min (CR10, CR15 and CR20), and after peripheral muscarinic blockade provoked by the administration of low and high doses of atropine (LD and HD). It is found that: (1) regularity of the RR interval series is around 0.209; (2) this increases during T, CR10 and HD; (3) the systolic arterial pressure (SAP) series is more regular (0.406) and its regularity is not affected by the specified experimental conditions; (4) the muscle sympathetic (MS) series is a complex signal (0.093) and its regularity is not influenced by HD and LD; (5) the RR interval and SAP series are significantly, though weakly, synchronised (0.093) and their coupling increases during T, CR10 and CR15; (6) the RR interval and respiration are coupled (0.152) and their coupling increases during CR10; (7) SAP and respiration are significantly synchronised (0.108) and synchronisation increases during CR10; (8) MS and respiration are uncoupled and become coupled (0.119) after HD; (9) the RR interval, SAP and respiration are significantly co-ordinated (0.118) and co-ordination increases during CR10 and CR15; (10) during HD the co-ordination among SAP, MS and the respiratory signal is larger than that among the RR interval, SAP, MS and the respiratory signal, thus indicating that the RR interval contributes towards reducing co-ordination.
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Affiliation(s)
- A Porta
- Dipartimento di Scienze Precliniche, Università' degli Studi di Milano, Italy.
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Bernorio S, Pecis M, Guzzetti S, Negri L. Genic amplification test in the diagnosis of mammary and disseminated tuberculosis. Int J Tuberc Lung Dis 1999; 3:83-4. [PMID: 10094177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023] Open
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33
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Guzzetti S, Mennini T, Cagnotto A, Di Biasi P, Scrofani R, Mezzetti S, Cogliati C, Paglia S, Malliani A. Myocardial beta-adrenergic and muscarinic receptor density in cardiac pressure or volume overload. J Mol Cell Cardiol 1998; 30:2095-102. [PMID: 9799661 DOI: 10.1006/jmcc.1998.0773] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Decreased myocardial beta-adrenergic receptor density has been demonstrated in experimental and clinical models of cardiac disease. Nevertheless, the individual role played by pressure or volume overload in determining the receptor downregulation has never been described in humans. Moreover, no data have been reported about the reversibility of the downregulation after non-pharmacological improvement of cardiac function. In the present study, we measured the myocardial beta-adrenergic and muscarinic receptor density, using an autoradiographic method, in 14 patients with cardiac pressure overload (aortic stenosis) and in five patients with cardiac volume overload (aortic regurgitation). Five patients with aortic stenosis were studied again six months after successful valve replacement. A significant lower density of beta-adrenergic receptors was observed in patients with a chronic pressure overload compared to those with a chronic volume overload (20+/-2 and 28+/-2 fmol/mg protein, respectively P<0.05). No significant differences were found between the two groups regarding beta-adrenoceptor sub-types proportion and muscarinic receptor density. Six months after successful aortic valve replacement, we observed a significant upregulation of the beta-adrenoceptor density (delta 29+/-9 fmol/mg protein P<0.05). In conclusion, these observations indicate that: (a) the type of left ventricle haemodynamic overload may be a quantitative determinant factor in the myocardial beta-adrenoceptor downregulation; (b) the reduction of a pathological cardiac load leads to an upregulation of these receptors.
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Affiliation(s)
- S Guzzetti
- Divisione di Medicina Interna, Divisione di Cardiochirurgia, Ospedale "L.Sacco"Università degli Studi di Milano, Italy
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Malliani A, Pagani M, Furlan R, Guzzetti S, Lucini D, Montano N, Cerutti S, Mela GS. Individual recognition by heart rate variability of two different autonomic profiles related to posture. Circulation 1997; 96:4143-5. [PMID: 9416881 DOI: 10.1161/01.cir.96.12.4143] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND Power spectrum analysis of heart rate variability (HRV) can estimate the state of sympathovagal balance modulating sinus node activity. In view of the large distribution of spectral variables, a recognition of well-defined physiological conditions has never been attempted on an individual basis. METHODS AND RESULTS We considered 10 spectral variables extracted from short segments (200 to 500 cardiac cycles) of 350 ECG tracings recorded in normal subjects in both supine and upright positions (700 patterns). The tracings were first ordered consecutively and subsequently assigned alternatively to a training or to a test set (each consisting of 175 cases, providing 350 patterns considered to be independent). A forecasting linear method estimated a normalized activation index (ranging from -1 for supine to +1 for upright) that concentrated the information derived from spectral variables and that identified, in the test set, individual by individual, approximately 84% of corresponding body postures. CONCLUSIONS The combined use of spectral methodology and forecasting analysis has revealed an information content embedded, per se, in a short series of RR intervals capable of recognizing, individual by individual, two different autonomic profiles related to posture.
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Affiliation(s)
- A Malliani
- Medicina Interna II, Ospedale L. Sacco, Università degli Studi di Milano, Italy.
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35
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Guzzetti S, Cogliati C, Mezzetti S, Turiel M, Lombardi F, Malliani A. Heart rate and systolic arterial blood pressure variabilities in the progression of chronic heart failure. Clin Sci (Lond) 1996; 91 Suppl:37-9. [PMID: 8813823 DOI: 10.1042/cs0910037supp] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- S Guzzetti
- Centro Ricerche Cardiovascolari, CNR, Ospedale L. Sacco, Italy
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36
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Guzzetti S, Signorini MG, Cogliati C, Mezzetti S, Porta A, Cerutti S, Malliani A. Non-linear dynamics and chaotic indices in heart rate variability of normal subjects and heart-transplanted patients. Cardiovasc Res 1996. [DOI: 10.1016/s0008-6363(95)00159-x] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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37
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Guzzetti S, Signorini MG, Cogliati C, Mezzetti S, Porta A, Cerutti S, Malliani A. Non-linear dynamics and chaotic indices in heart rate variability of normal subjects and heart-transplanted patients. Cardiovasc Res 1996; 31:441-6. [PMID: 8681331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
OBJECTIVES Heart rate variability (HRV) is characterised by a variety of linear, non-linear, periodical and non-periodical oscillations. The aim of the present study was mainly to investigate the role played by neural mechanisms in determining non-linear and non-periodical components. METHODS Analysis was performed in 7 recently heart transplanted patients and in 7 controls of similar age whose HRV signal was collected during 24 h. Parameters that quantify non-linear dynamic behaviour, in a time series, were calculated. We first assessed the specific non-linear nature of the time series by a test on surrogate data after Fourier phase randomization. Furthermore, the D2 correlation dimension, K2 Kolmogorov entropy, and H self-similarity exponent of the signal were estimated. From this last parameter, the dimension D = 1/H can be obtained. In order to assess whether the dynamics of the system are compatible with chaotic characteristics, the entire spectrum of Lyapunov exponents was calculated. We used return maps to graphically represent the non-linear and non-periodical behaviours in patients and controls. RESULTS Surrogate data suggest that the HRV time courses have unique non-linear characteristics. D2, K2 and 1/H parameters were significantly lower in transplanted subjects than in controls. Positivity of the first Lyapunov exponent indicates divergence of trajectories in state-space. Furthermore, the display of return maps on projections obtained after Singular Value Decomposition, especially in low-complexity data (as in transplanted patients), shows a structure which is suggestive of a strange attractor. These findings support the hypothesis that chaotic dynamics underlie HRV. CONCLUSION These results indicate that non-linear dynamics are likely to be present in HRV control mechanisms, giving rise to complex and qualitatively different behaviours. System complexity decreases in transplanted patients and this may be related to loss of the neural modulation of heart rate.
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Affiliation(s)
- S Guzzetti
- Centro Ricerche Cardiovascolari del CNR, Medicina Interna II, Università di Milano, Italy
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38
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Choudhury L, Guzzetti S, Lefroy DC, Nihoyannopoulos P, McKenna WJ, Oakley CM, Camici PG. Myocardial beta adrenoceptors and left ventricular function in hypertrophic cardiomyopathy. Heart 1996; 75:50-4. [PMID: 8624872 PMCID: PMC484222 DOI: 10.1136/hrt.75.1.50] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
OBJECTIVE To assess the relation between left ventricular function and myocardial beta adrenoceptor density. METHODS 17 patients with hypertrophic cardiomyopathy, six with and 11 without heart failure, were studied. Left ventricular function was assessed by echocardiography, and myocardial beta adrenoceptors by positron emission tomography. Patient data were compared with those obtained in normal controls. RESULTS Myocardial beta adrenoceptor density in the 17 patients was 7.00 (SD 1.90) pmol/g v 11.50 (2.18) pmol/g in normal controls (P < 0.01). beta Adrenoceptor density in the six patients with left ventricular failure was 5.61 (0.88) pmol/g v 7.71 (1.86) pmol/g in the 11 patients with normal ventricular function (P < 0.05), and there was a significant correlation (r = 0.52; P < 0.05) between left ventricular fractional shortening and myocardial beta adrenoceptor density. A positive correlation (r = 0.51; P < 0.05) was also found between myocardial beta adrenoceptor density and the E/A transmitral flow ratio, an index of left ventricular diastolic function. CONCLUSIONS There is myocardial beta adrenoceptor downregulation in patients with hypertrophic cardiomyopathy with or without signs of heart failure.
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Affiliation(s)
- L Choudhury
- MRC Clinical Sciences Centre, Hammersmith Hospital, London
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40
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Gnecchi-Ruscone T, Montano N, Guzzetti S, Pagani M. A circadian perspective on myocardial ischaemia. J Cardiovasc Risk 1995; 2:505-9. [PMID: 8665368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The non-uniform occurrence of myocardial ischaemia, with a trough at night and a peak in the morning, is at the base of the concept of a circadian distribution of coronary events. Cardiovascular variables known to influence the occurrence of ischaemia have similar rhythms, and a likely culprit could be hidden among them. Nevertheless, in many cases an identifiable trigger is lacking and the prediction of ischaemia is still elusive.
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41
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Boldorini R, Guzzetti S, Meroni L, Quirino T, Cristina S, Monga G. Acute hepatic and renal failure caused by Pneumocystis carinii in patients with AIDS. J Clin Pathol 1995; 48:975-8. [PMID: 8537506 PMCID: PMC502963 DOI: 10.1136/jcp.48.10.975] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Clinical and pathological findings are described in two AIDS patients with Pneumocystis carinii infection who received prophylactic treatment with nebulised pentamidine and developed unusual hepatic and renal failure. Histological examination showed clumps of P carinii massively obstructing hepatic sinuses and portal vessels in the first patient, and merular and intertubular capillaries in the second. These findings could explain the unusual clinical features, characterised by acute hepatic and renal failure.
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Affiliation(s)
- R Boldorini
- Dipartimento di Scienze Mediche, II Facoltà di Medicina e Chirurgia di Novara-Università di Torino, Italy
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Abstract
Using spectral analysis of heart rate and systolic arterial pressure variabilities, the study was set up to evaluate cardiovascular efferent autonomic modulation in patients with different degrees of chronic heart failure. We studied 30 patients with stable chronic heart failure and 15 controls of similar age. ECG, arterial blood pressure and respiratory signal were recorded at rest, during controlled respiration and during passive head-up tilting. R-R interval periods of 256-512 were analysed. Routine 2D echocardiogram and Doppler studies were also carried out. As expected, we found a decrease in the mean and variance of R-R intervals in patients with sever heart failure. In New York Heart Association (NYHA) class II patients, the power spectral pattern of R-R variability was characterized by the predominance of the low frequency component (72 +/- 3 nu), considered a marker of sympathetic activity, and by its unresponsiveness to tilting. Patients in NYHA class III also presented blunted changes in spectral components during tilting. A drastic decrease in the variance of R-R intervals (191 +/- 58 vs 1056 +/- 149 ms2 in controls) and an almost complete absence of the low frequency spectral component (8 +/- 3 nu) were present in patients in NYHA class IV. Controlled respiration, which in normal subjects decreased the low frequency component, induced changes that blunted progressively as heart failure increased. These data suggest that autonomic neural modulation and cardiovascular response to neural activity differ at different stages of the disease.
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Affiliation(s)
- S Guzzetti
- Centro Ricerche Cardiovascolari del CNR, Milano, Italy
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Vitri P, Caravati C, Guzzetti S, De Angelis S, Buzzi G, Gornati R. [Adrenal metastasis of choroidal melanoma: a case report]. Ann Ital Chir 1994; 65:537-41. [PMID: 7733576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
We report on the case of a 32 years old man submitted to right eye enucleation twelve years before for a choroidal melanoma. We observe a metastases located in the left adrenal gland. The blood-tests, the TAC of the abdomen did not show other localizations, while during laparotomy were discovered metastases in the pancreas and in the omentum. In this case, the age of tumor's development, the age of clinical manifestation, the period between the enucleation and the appearance of the metastases and their localization are exceptions to the normal biological behaviour of the choroidal melanoma.
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Affiliation(s)
- P Vitri
- Università degli Studi di Milano, Istituto di Scienze Biomediche L. Sacco
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Di Biasi P, Pajé A, Salati M, Bozzi G, Viecca M, Cialfi A, Di Biasi M, Guzzetti S, Santoli C. Surgical timing in aortic regurgitation: left ventricular function analysis by contractility score. Ann Thorac Surg 1994; 58:509-15. [PMID: 8067855 DOI: 10.1016/0003-4975(94)92241-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
In 32 patients with aortic regurgitation, angiographic evaluation of global left ventricular performance before and after aortic valve replacement was carried out by means of a computer-analyzed contractility scoring system. A strong correlation was detected between the preoperative and postoperative contractility score. Postoperatively, the score decreased in all but 3 patients, becoming normal or near normal in 21 of 27 patients whose preoperative value had been less than 40. However, all 5 patients with a preoperative contractility score of 40 or greater exhibited a persistently elevated score after operation that indicated the presence of irreversible contractile dysfunction. Patients in groups A and B (preoperative score, 0 to 40) experienced a good surgical outcome, and at 5-year follow-up were in New York Heart Association functional class I. Patients in group C (preoperative score, > 40) altogether had a very poor surgical outcome, although they did experience a short to midterm period of symptomatic relief. It is important to offer aortic valve replacement to patients with aortic regurgitation before their chances for a good functional result are lost. The computer-analyzed contractility score may be a useful index for determining the optimal timing of operation in these patients, particularly those who show features consistent with impaired left ventricular function but are asymptomatic and who should undergo aortic valve replacement before symptoms of definitive left ventricular failure develop.
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Affiliation(s)
- P Di Biasi
- Divisione di Chirurgia Toracica e Cardiovascolare, Ospedale Luigi Sacco, Milano, Italy
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Gnecchi-Ruscone T, Piccaluga E, Guzzetti S, Contini M, Montano N, Nicolis E. Morning and Monday: critical periods for the onset of acute myocardial infarction. The GISSI 2 Study experience. Eur Heart J 1994; 15:882-7. [PMID: 7925507 DOI: 10.1093/oxfordjournals.eurheartj.a060605] [Citation(s) in RCA: 76] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The onset of acute myocardial infarction (AMI) is unevenly distributed over the 24 h and the week. While presence of a morning peak is generally agreed upon, contrasting results had been obtained regarding other periods of the day, probably due to differences of origin, size and composition of the populations. The 24 h and weekly distributions were studied within 6 h from the beginning of the symptoms in a population following a Latin life-style, who were enrolled in the GISSI 2 Study (n = 11472). Subgroups (smokers, the elderly (> 65 years), diabetics, hypertensives) were also considered. Six hour periods starting at midnight were tested for uniformity. Circadian non-uniformity was found. Events increased in the morning hours and reduced during the night regardless of the day of the week. The night and day difference was attenuated in smokers and diabetics. Non-uniformity of the events was also found among the days of the week. AMI significantly increased in non-smokers on Monday. We suggest that there is a night-day gradient (characterized by the short time interval between the two frequency extremes) in the time of onset of AMI. The different distribution in smokers stresses the possible unfavourable and masking effect of a heightened sympathetic tone during the day while the general protective role of the night hours is preserved. Moreover, the increased incidence of events on Monday may suggest the importance of the shift from a period of non-scheduled to scheduled activity.
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Affiliation(s)
- T Gnecchi-Ruscone
- Servizio di Cardiologia, Ospedale S. Leopoldo Mandic, Merate (Co), Italy
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Piraneo S, Galimberti A, Guzzetti S, Leopaldi E, Poggi L, Vitri P, Bastagli A. [Asymptomatic hyperparathyroidism. Influence of PTH values on the therapeutic decision]. MINERVA CHIR 1994; 49:497-501. [PMID: 7970051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The majority of patients affected by primary hyperparathyroidism present now in surgical series are little or totally asymptomatic. This is due to widespread use of multiphasic screening for hypercalcemia as far as to more liberal indications for parathyroid exploration. The debate about the need for parathyroidectomy is open in these patients, having few or no signs at all of primary hyperparathyroidism, because conservative treatment has yielded confused results. The authors analyzed preoperative biochemical values and surgical outcome from 26 patients affected by primary hyperparathyroidism. Thirteen cases had overt primary hyperparathyroidism (group A) and 13 had asymptomatic disease (group B). Patients in group A had higher preoperative PTH values than patients in group (p < 0.05). After surgery, the patients in group A showed parathyroid glands which weighted significatively more than ones in group B (p +/- 0.01). Further, a significant correlation between preoperative PTH value and glandular weight was demonstrated in all cases. The authors conclude surgery for patients having mild primary hyperparathyroidism may give some problems related to the very small size of abnormal glands found during operation. We advise a close follow-up for these patients initially without treatment: surgery should be recommended for those showing PTH values higher than 150 pg/ml.
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Affiliation(s)
- S Piraneo
- Cattedra di Patologia Chirurgica, Istituto di Scienze Biomediche L. Sacco, Milano
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Piraneo S, Vitri P, Galimberti A, Guzzetti S, Salvaggio A, Bastagli A. Recurrence of goitre after operation in euthyroid patients. Eur J Surg 1994; 160:351-356. [PMID: 7948353] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
OBJECTIVE To try and resolve some of the problems associated with the treatment of goitre in euthyroid patients. DESIGN Retrospective open study SETTING University hospital SUBJECTS 106 out of a total of 161 euthyroid patients operated on for goitre from 1974-1988. Those who underwent total thyroidectomy (n = 14), in whom the histological diagnosis was thyroiditis (n = 10), or who were lost to follow up (n = 31) were excluded from the study. MAIN OUTCOME MEASURES Recurrence of goitre, and correlation with type of operation, age, and histological type. RESULTS 62 Patients underwent unilateral, and 44 bilateral resections. There were 24 recurrences (23%), 13 of which were subclinical; 19 occurred after unilateral, and 5 after bilateral, resections (p = 0.02). There were no significant associations between recurrence and age or histological type. CONCLUSION Subtotal thyroidectomy is the treatment of choice for goitre in euthyroid patients.
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Affiliation(s)
- S Piraneo
- Department of Surgery, L. Sacco Hospital, University of Milan, Italy
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48
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Signorini MG, Cerutti S, Guzzetti S, Parola R. Non-linear dynamics of cardiovascular variability signals. Methods Inf Med 1994; 33:81-4. [PMID: 8177086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Long-term regulation of beat-to-beat variability involves several different kinds of controls. A linear approach performed by parametric models enhances the short-term regulation of the autonomic nervous system. Some non-linear long-term regulation can be assessed by the chaotic deterministic approach applied to the beat-to-beat variability of the discrete RR-interval series, extracted from the ECG. For chaotic deterministic systems, trajectories of the state vector describe a strange attractor characterized by a fractal of dimension D. Signals are supposed to be generated by a deterministic and finite dimensional but non-linear dynamic system with trajectories in a multi-dimensional space-state. We estimated the fractal dimension through the Grassberger and Procaccia algorithm and Self-Similarity approaches of the 24-h heart-rate variability (HRV) signal in different physiological and pathological conditions such as severe heat failure, or after heart transplantation. State-space representations through Return Maps are also obtained. Differences between physiological and pathological cases have been assessed and generally a decrease in the system complexity is correlated to pathological conditions.
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Affiliation(s)
- M G Signorini
- Department of Biomedical Engineering, Polytechnic University, Milano, Italy
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Guzzetti S, Cogliati C, Broggi C, Carozzi C, Caldiroli D, Lombardi F, Malliani A. Influences of neural mechanisms on heart period and arterial pressure variabilities in quadriplegic patients. Am J Physiol 1994; 266:H1112-20. [PMID: 8160814 DOI: 10.1152/ajpheart.1994.266.3.h1112] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The heart period (R-R) variability power spectrum presents two components, at low (LF; approximately 0.10 Hz) and high (approximately 0.25 Hz) frequencies, whose reciprocal powers appear to furnish an index of sympathovagal interaction modulating heart rate. In addition, the LF component of the systolic arterial pressure variability spectrum furnishes a marker of sympathetic modulation of vasomotor activity. The contribution of spinal and supraspinal neural circuits to the genesis of these rhythmic oscillatory components remains largely unsettled. Therefore we performed spectral analysis of R-R and systolic arterial pressure variabilities in 15 chronic neurologically complete quadriplegic patients (QP) and in 15 control subjects during resting conditions, controlled respiration, and head-up tilt. At rest, in seven QP the LF component was undetectable in both cardiovascular variability spectra; in two QP this component was present only in R-R variability spectrum, whereas the remaining six showed a significantly reduced LF in both signals. In QP, the LF component, when present, underwent paradoxical changes with respect to controls, decreasing during tilt and increasing during controlled respiration. In five QP in whom the recording session was repeated after 6 mo, a significant increase in LF was observed in both variability spectra. These data confirm the finding that a disconnection of sympathetic outflow from supraspinal centers can cause the disappearance of the LF spectral component. However, LF presence in some QP supports the hypothesis of a spinal rhythmicity likely to be modulated by the afferent sympathetic activity.
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Guzzetti S, Dassi S, Balsamà M, Ponti GB, Pagani M, Malliani A. Altered dynamics of the circadian relationship between systemic arterial pressure and cardiac sympathetic drive early on in mild hypertension. Clin Sci (Lond) 1994; 86:209-15. [PMID: 8143431 DOI: 10.1042/cs0860209] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
1. This study was designed to test the hypothesis that simultaneous non-invasive assessment of the circadian variations in both intermittent arterial pressure and the continuous 24 h changes of spectral markers of cardiac neural control could provide new information on cardiovascular regulatory mechanisms, in hypertensive patients and normotensive subjects. To test this hypothesis we studied 18 subjects with mild hypertension and 11 normotensive subjects in whom we recorded simultaneously non-invasive intermittent arterial pressure and Holter electrocardiogram for 24 h. We also studied the same subjects during resting and standing conditions in the clinical laboratory. 2. The normalized power of the low-frequency (approximately 0.1 Hz) spectral component of R-R interval variability, considered mainly a marker of sympathetic drive to the sino-atrial node, was, at rest, significantly higher in the hypertensive than in the normotensive subjects, as already reported. Moreover, the values of the low-frequency component at rest recorded in the clinical laboratory were significantly correlated with those obtained from ambulatory recording during night rest. The decrease in the values of arterial pressure during the night-time was accompanied by a reduction in the power of the low-frequency component only in the case of normotensive subjects. Accordingly, the slope of the regression of the low-frequency component as a function of systolic arterial pressure during ambulatory recordings was steep in normotensive subjects and flat in hypertensive subjects.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- S Guzzetti
- Centro Ricerche Cardiovascolari del CNR, Centro Fidia, Ospedale Luigi Sacco, Università di Milano, Italy
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