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Zaid GK, Saini C, Awais K, Shah NS. Autistic Regression Sequelae or Relapse for NMDA Receptor Antibody Encephalitis. Neurology 2022. [DOI: 10.1212/01.wnl.0000903384.12380.b2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
ObjectiveTo highlight a pediatric presentation of autistic regression secondary to relapsing NMDA receptor antibody encephalitis (NMDARAE) post-HSV infection.BackgroundIt is reported that 30% of patients develop NMDA receptor antibodies (NMDARA) after HSV Encephalitis. Previous studies have demonstrated a significant association between prior HSV-1 infection and NMDARAE, a diagnosis often overlooked due to diverse neurological manifestations.Design/MethodsNA.ResultsThis case highlights a 5-year-old female presenting with fever and refractory status epilepticus, was diagnosed with HSV Encephalitis requiring prolonged hospitalization. At discharge she had insomnia, mutism, dyskinetic movements, atonic seizures, and developmental regression. At 3 months post-discharge EEG exhibited multiple generalized myoclonic, myoclonic tonic, and atonic seizures, MRI brain demonstrated right temporal lobe encephalomalacia with immunologic workup demonstrating positive serum and CSF NMDARA. She underwent treatment with intravenous steroids followed by plasmapheresis and then rituximab with an improved clinical response and seizure control at 6 months. At 9 months, she displayed behavioral changes with diagnosis of ADHD with autistic regression. Workup was positive for NMDARA in the CSF (18 months post-presentation) and EEG showed diffuse epileptiform discharges activated during sleep. She was treated with steroids followed by rituximab. At follow-up, she showed improved social interaction, sleep, and seizure control with persistence of some autistic and ADHD features.ConclusionsAbout 90% of patients with NMDARE present with prominent behavioral manifestations, with challenges in differentiating from psychiatric diseases. Relapse is reported in 12-24% of cases and is associated with delayed treatment and the female gender. NMDARAE relapse post-HSV Encephalitis is underreported, especially cases demonstrating autistic regression, as in our case. In conclusion, given overlapping and subtle symptoms, it is crucial to recognize the varying presentations and early diagnosis of NMDARAE relapse for effective treatment and better outcome.
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Zaid GK, Saini C, Gachechiladzi L, Salhab M. Autoimmune Encephalitis With Ganglionic a3-AChR Antibodies. Neurology 2022. [DOI: 10.1212/01.wnl.0000903380.14508.43] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
ObjectiveTo describe a case of autoimmune encephalitis presented as new onset refractory nonconvulsive status epilepticus and autonomic failure caused by alpha-3 ganglionic acetylcholine receptor autoantibodies (a3-AChR Ab).BackgroundAutoimmune autonomic ganglionopathy (AAG) is rare acquired dysautonomia in adults due to a3-AChR Ab. A patient typically presents with subacute autonomic dysfunction, and encephalitis has not been reported yet.Design/MethodsNA.ResultsA 60 years old female presented with progressive worsening of mental status for two weeks. Vital signs were normal. The patient was somnolent, nonverbal, with tonic non-reactive pupils on the exam. CT head showed multiple subcortical hypodensities. MRI brain demonstrated T2-FLAIR hyperintense lesions in bifrontal lobes sparing the U-fibers, with abnormal leptomeningeal/pial perivenular type enhancement. MRI C/T spine, CT chest/Abd/pelvis were negative. Although serum and CSF testing showed inflammatory markers, meningoencephalitis and autoimmune encephalitis panel were negative, except for the serum Paraneoplastic panel was positive with high titer a3-AChR Abs. EEG showed nonconvulsive status epilepticus, which required management with three antiseizure medications. Initially, the patient had little response to empirical pulse methylprednisolone therapy. Later showed good clinical response with plasmapheresis. Later on she presented with nonobstructive small bowel obstruction, resolved with another pulse steroid therapy, discharged on dexamethasone taper. On a three-month follow-up, the patient was in near clinical remission, supported with resolved lesions on a repeat MRI. She never relapsed after two years of follow-up.ConclusionsStudies have shown that a3-AChR Abs can result in diverse neurological manifestations, mainly dysautonomia. Our patient presented with encephalitis, dysautonomia, and refractory nonconvulsive status epilepticus. Scans suggested diffuse leukoencephalopathy, patient was found to have high 3-ACHR antibody seropositivity. Initially, the patient was steroid-resistant but showed clinical improvement with plasmapheresis. We have described an interesting case of encephalitis likely associated with a3-AChR Ab that has not been previously described. More studies are required to confirm this association.
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Saini C, Zaid GK, Gachechiladze L, Krishnan R. Unusual Post–COVID-19 Presentation With Tetra Ventricular Hydrocephalus: A Case Report. Neurol Clin Pract 2022; 12:e25-e27. [DOI: 10.1212/cpj.0000000000001174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Accepted: 03/03/2022] [Indexed: 11/15/2022]
Abstract
Abstract:Objective:COVID 19 infection is suggested as one of the causes for hydrocephalus (HCP) of unknown etiology. COVID-19 infection may present with a range of neurologic symptoms given viral neurotropic and neuroinvasive properties. Post-infectious hydrocephalus is a severe complication as a potential sequela of COVID-19 infection.Methods:We identified a patient with a history of recent COVID-19 infection who presented with chronic progressive headaches with nausea, vomiting, and blurry vision over two weeks.Results:Neurological examination showed bilateral papilledema. Head CT scan showed tetraventricular enlargement and marked fourth ventricular dilation. Cine MRI showed fourth ventricular turbulent CSF flow. The patient underwent external ventricular drain (EVD) placement and exploratory suboccipital craniotomy, which revealed a sub-arachnoid web that was microsurgically resected. Reconstituted CSF flow resolved the patient's symptoms and prevented complications.Discussion:Fourth ventricular outlet obstruction is a rare cause of tetraventricular hydrocephalus. In most cases, it is associated with a history of inflammatory conditions or hemorrhage. In our case, history of recent COVID-19 infection and normal imaging prior to COVID-19 make COVID-19 the most probable explanation for HCP. We suggest considering COVID-19 infection in the differential diagnosis of HCP of unclear etiologyPractical implication:A pearl of wisdom for the practicing clinician: “Consider COVID-19 as the cause of Hydrocephalus of unclear etiology”.
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Probst S, Weller CD, Bobbink P, Saini C, Pugliese M, Skinner MB, Gethin G. Prevalence and incidence of venous leg ulcers-a protocol for a systematic review. Syst Rev 2021; 10:148. [PMID: 33980324 PMCID: PMC8117489 DOI: 10.1186/s13643-021-01697-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Accepted: 05/03/2021] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND Venous leg ulcers (VLUs) are chronic wounds characterized by slow healing and high recurrence. Information on prevalence and incidence is essential for ascertaining the burden of VLU on the health care system and to inform epidemiological research, priority setting, and health care planning. The objective of this protocol is to present a transparent process for how we plan to review the existing international literature on the prevalence and incidence of VLU as well as the characteristics of the population reported within these studies. METHODS An exploratory search was performed using MEDLINE via PubMed and CINHAL via Ebsco to identify concepts, keywords, MeSH terms, and headings to identify study types looking at data of VLU prevalence and/or incidence and related patient characteristics. The findings of this exploratory search will determine the final search strategy. The titles and abstracts of the identified articles will be screened independently be two authors for relevance. Study which pass the quality assessment will be included. Data extraction will be performed independently by two authors and in accordance with a pre-designed data extraction form. If the data allows, a meta-analysis will be performed otherwise a descriptive summary of the findings will be conducted. DISCUSSION The results of this review will contribute to the evidence base on VLU occurrence and may inform the decision making of healthcare professionals, policy-makers, and consumers. It will also inform future research in this area of VLU care. SYSTEMATIC REVIEW REGISTRATION PROSPERO CRD42020205855.
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Affiliation(s)
- S Probst
- HES-SO University of Applied Sciences and Arts Western Switzerland, School of Health Sciences, Avenue de Champel 47, 1206, Geneva, Switzerland.
| | - C D Weller
- Department of Epidemiology and Preventive Medicine, School of Public Health and Preventive Medicine, The Alfred Hospital, Monash University, Melbourne, Australia
| | - P Bobbink
- HES-SO University of Applied Sciences and Arts Western Switzerland, Geneva School of Health Sciences, Geneva, Switzerland
| | - C Saini
- HES-SO University of Applied Sciences and Arts Western Switzerland, Geneva School of Health Sciences, Geneva, Switzerland
| | - M Pugliese
- HES-SO University of Applied Sciences and Arts Western Switzerland, Geneva School of Health Sciences, Geneva, Switzerland
| | - Monika Buehrer Skinner
- Institute of Epidemiology, Biostatistics and Prevention, Director of Public Health Education Program, University of Zurich, Zurich, Switzerland
| | - G Gethin
- School of Nursing and Midwifery, Aras Moyola, NUI Galway, Galway, Ireland
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Saini C, Srivastava R, Khanna N, Ramesh V, Sharma A. IL-6 promotes pathogenic Th17 in T1R leprosy reactions by stimulating Il17 producing by IL-6R pathway. Int J Infect Dis 2020. [DOI: 10.1016/j.ijid.2020.09.1212] [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: 11/28/2022] Open
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Kashyap R, Vashistha K, Saini C, Dutt T, Raman D, Bansal V, Singh H, Bhandari G, Ramakrishnan N, Seth H, Sharma D, Seshadri P, Daga MK, Gurjar M, Javeri Y, Surani S, Varon J. Critical care practice in India: Results of the intensive care unit need assessment survey (ININ2018). World J Crit Care Med 2020; 9:31-42. [PMID: 32577414 PMCID: PMC7298589 DOI: 10.5492/wjccm.v9.i2.31] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2019] [Revised: 04/27/2020] [Accepted: 05/13/2020] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND A diverse country like India may have variable intensive care units (ICUs) practices at state and city levels.
AIM To gain insight into clinical services and processes of care in ICUs in India, this would help plan for potential educational and quality improvement interventions.
METHODS The Indian ICU needs assessment research group of diverse-skilled individuals was formed. A pan- India survey "Indian National ICU Needs" assessment (ININ 2018-I) was designed on google forms and deployed from July 23rd-August 25th, 2018. The survey was sent to select distribution lists of ICU providers from all 29 states and 7 union territories (UTs). In addition to emails and phone calls, social medial applications-WhatsApp™, Facebook™ and LinkedIn™ were used to remind and motivate providers. By completing and submitting the survey, providers gave their consent for research purposes. This study was deemed eligible for category-2 Institutional Review Board exempt status.
RESULTS There were total 134 adult/adult-pediatrics ICU responses from 24 (83% out of 29) states, and two (28% out of 7) UTs in 61 cities. They had median (IQR) 16 (10-25) beds and most, were mixed medical-surgical, 111(83%), with 108(81%) being adult-only ICUs. Representative responders were young, median (IQR), 38 (32-44) years age and majority, n = 108 (81%) were males. The consultants were, n = 101 (75%). A total of 77 (57%) reported to have 24 h in-house intensivist. A total of 68 (51%) ICUs reported to have either 2:1 or 2≥:1 patient:nurse ratio. More than 80% of the ICUs were open, and mixed type. Protocols followed regularly by the ICUs included sepsis care, ventilator- associated pneumonia (83% each); nutrition (82%), deep vein thrombosis prophylaxis (87%), stress ulcer prophylaxis (88%) and glycemic control (92%). Digital infrastructure was found to be poor, with only 46 % of the ICUs reporting high-speed internet availability.
CONCLUSION In this large, national, semi-structured, need-assessment survey, the need for improved manpower including; in-house intensivists, and decreasing patient-to-nurse ratios was evident. Sepsis was the most common diagnosis and quality and research initiatives to decrease sepsis mortality and ICU length of stay could be prioritized. Additionally, subsequent surveys can focus on digital infrastructure for standardized care and efficient resource utilization and enhancing compliance with existing protocols.
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Affiliation(s)
- Rahul Kashyap
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, MN 55905, United States
| | - Kirtivardhan Vashistha
- Department of Infectious Disease, Mayo Clinic, Rochester, MN 55905, United States
- Department of Internal Medicine, Allegheny General Hospital, Pittsburgh, PA 15212, United States
| | - Chetan Saini
- Department of Radiology, Mayo Clinic, Rochester, MN 55905, United States
- Department of Medicine, Jacobi Medical Center/Albert Einstein College of Medicine, Bronx, NY 14061, United States
| | - Taru Dutt
- Department of Neurology, Mayo Clinic, Rochester, MN 55905, United States and Department of Psychiatry, Hennepin County Medical Center, Minneapolis, MN 55415, United States
| | - Dileep Raman
- Department of Medicine, Cloud Physician Healthcare, Bangalore 560038, India
| | - Vikas Bansal
- Department of Critical Care Medicine, Mayo Clinic, Rochester, MN 55905, United States
| | - Harpreet Singh
- Department of Internal Medicine, Maulana Azad Medical College & Associated Hospitals, New Delhi, Delhi 110002, India
| | - Geeta Bhandari
- Department of Anesthesiology, Government Medical College, Haldwani, Nainital 263129, India
| | | | - Harshit Seth
- Department of Hospitalist Medicine, Allegany Clinic, Allegany Health Network, Pittsburgh, PA 15222, United States
| | - Divya Sharma
- Department of Medicine, MAAGF Healthcare, Chennai 600024, India
| | | | - Mradul Kumar Daga
- Department of Internal Medicine and Center for Occupational and Environment Health, Maulana Azad Medical College, New Delhi, Delhi 110002, India
| | - Mohan Gurjar
- Department of Critical Care Medicine, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow 226014, India
| | - Yash Javeri
- Department of Critical Care Medicine, Regency Super Speciality Hospital, Lucknow 208005, India
- Nayati Healthcare, New Delhi, Delhi 110065, India
| | - Salim Surani
- Department of Pulmonary and Critical Care Medicine, Texas A&M University, College Station, TX 77843, United States
| | - Joseph Varon
- Department of Critical Care, United Memorial Medical Center, Houston, TX 77091, United States
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Saini C, Petrenko V, Pulimeno P, Giovannoni L, Berney T, Hebrok M, Howald C, Dermitzakis ET, Dibner C. A functional circadian clock is required for proper insulin secretion by human pancreatic islet cells. Diabetes Obes Metab 2016; 18:355-65. [PMID: 26662378 DOI: 10.1111/dom.12616] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Revised: 10/08/2015] [Accepted: 12/01/2015] [Indexed: 01/20/2023]
Abstract
AIM To determine the impact of a functional human islet clock on insulin secretion and gene transcription. METHODS Efficient circadian clock disruption was achieved in human pancreatic islet cells by small interfering RNA-mediated knockdown of CLOCK. Human islet secretory function was assessed in the presence or absence of a functional circadian clock by stimulated insulin secretion assays, and by continuous around-the-clock monitoring of basal insulin secretion. Large-scale transcription analysis was accomplished by RNA sequencing, followed by quantitative RT-PCR analysis of selected targets. RESULTS Circadian clock disruption resulted in a significant decrease in both acute and chronic glucose-stimulated insulin secretion. Moreover, basal insulin secretion by human islet cells synchronized in vitro exhibited a circadian pattern, which was perturbed upon clock disruption. RNA sequencing analysis suggested alterations in 352 transcript levels upon circadian clock disruption. Among them, key regulators of the insulin secretion pathway (GNAQ, ATP1A1, ATP5G2, KCNJ11) and transcripts required for granule maturation and release (VAMP3, STX6, SLC30A8) were affected. CONCLUSIONS Using our newly developed experimental approach for efficient clock disruption in human pancreatic islet cells, we show for the first time that a functional β-cell clock is required for proper basal and stimulated insulin secretion. Moreover, clock disruption has a profound impact on the human islet transcriptome, in particular, on the genes involved in insulin secretion.
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MESH Headings
- CLOCK Proteins/antagonists & inhibitors
- CLOCK Proteins/genetics
- CLOCK Proteins/metabolism
- Cation Transport Proteins/antagonists & inhibitors
- Cation Transport Proteins/chemistry
- Cation Transport Proteins/genetics
- Cation Transport Proteins/metabolism
- Cells, Cultured
- Circadian Clocks/drug effects
- Colforsin/pharmacology
- GTP-Binding Protein alpha Subunits, Gq-G11/antagonists & inhibitors
- GTP-Binding Protein alpha Subunits, Gq-G11/chemistry
- GTP-Binding Protein alpha Subunits, Gq-G11/genetics
- GTP-Binding Protein alpha Subunits, Gq-G11/metabolism
- Gene Expression Profiling
- Gene Expression Regulation/drug effects
- Genes, Reporter/drug effects
- Humans
- Hyperglycemia/metabolism
- Insulin/metabolism
- Insulin Secretion
- Insulin-Secreting Cells/cytology
- Insulin-Secreting Cells/drug effects
- Insulin-Secreting Cells/metabolism
- Islets of Langerhans/cytology
- Islets of Langerhans/drug effects
- Islets of Langerhans/metabolism
- Potassium Channels, Inwardly Rectifying/antagonists & inhibitors
- Potassium Channels, Inwardly Rectifying/chemistry
- Potassium Channels, Inwardly Rectifying/genetics
- Potassium Channels, Inwardly Rectifying/metabolism
- Qa-SNARE Proteins/antagonists & inhibitors
- Qa-SNARE Proteins/chemistry
- Qa-SNARE Proteins/genetics
- Qa-SNARE Proteins/metabolism
- RNA Interference
- RNA, Small Interfering
- Sodium-Potassium-Exchanging ATPase/antagonists & inhibitors
- Sodium-Potassium-Exchanging ATPase/chemistry
- Sodium-Potassium-Exchanging ATPase/genetics
- Sodium-Potassium-Exchanging ATPase/metabolism
- Vesicle-Associated Membrane Protein 3/antagonists & inhibitors
- Vesicle-Associated Membrane Protein 3/chemistry
- Vesicle-Associated Membrane Protein 3/genetics
- Vesicle-Associated Membrane Protein 3/metabolism
- Zinc Transporter 8
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Affiliation(s)
- C Saini
- Endocrinology, Diabetes, Hypertension and Nutrition, Diabetes Centre, Faculty of Medicine, University of Geneva, Geneva, Switzerland
- Institute of Genetics and Genomics in Geneva (iGE3), Geneva, Switzerland
| | - V Petrenko
- Endocrinology, Diabetes, Hypertension and Nutrition, Diabetes Centre, Faculty of Medicine, University of Geneva, Geneva, Switzerland
- Institute of Genetics and Genomics in Geneva (iGE3), Geneva, Switzerland
| | - P Pulimeno
- Endocrinology, Diabetes, Hypertension and Nutrition, Diabetes Centre, Faculty of Medicine, University of Geneva, Geneva, Switzerland
- Diabetes Center, UCSF, San Francisco, CA, USA
| | - L Giovannoni
- Endocrinology, Diabetes, Hypertension and Nutrition, Diabetes Centre, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - T Berney
- Department of Surgery, Cell Isolation and Transplantation Centre, University Hospital of Geneva, Geneva, Switzerland
| | - M Hebrok
- Diabetes Center, UCSF, San Francisco, CA, USA
| | - C Howald
- Institute of Genetics and Genomics in Geneva (iGE3), Geneva, Switzerland
- Department of Genetic Medicine and Development, University of Geneva Medical School, Geneva, Switzerland
- Swiss Institute of Bioinformatics, Geneva, Switzerland
| | - E T Dermitzakis
- Institute of Genetics and Genomics in Geneva (iGE3), Geneva, Switzerland
- Department of Genetic Medicine and Development, University of Geneva Medical School, Geneva, Switzerland
- Swiss Institute of Bioinformatics, Geneva, Switzerland
| | - C Dibner
- Endocrinology, Diabetes, Hypertension and Nutrition, Diabetes Centre, Faculty of Medicine, University of Geneva, Geneva, Switzerland
- Institute of Genetics and Genomics in Geneva (iGE3), Geneva, Switzerland
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Gerber A, Saini C, Curie T, Emmenegger Y, Rando G, Gosselin P, Gotic I, Gos P, Franken P, Schibler U. The systemic control of circadian gene expression. Diabetes Obes Metab 2015; 17 Suppl 1:23-32. [PMID: 26332965 DOI: 10.1111/dom.12512] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Accepted: 05/25/2015] [Indexed: 11/28/2022]
Abstract
The mammalian circadian timing system consists of a central pacemaker in the brain's suprachiasmatic nucleus (SCN) and subsidiary oscillators in nearly all body cells. The SCN clock, which is adjusted to geophysical time by the photoperiod, synchronizes peripheral clocks through a wide variety of systemic cues. The latter include signals depending on feeding cycles, glucocorticoid hormones, rhythmic blood-borne signals eliciting daily changes in actin dynamics and serum response factor (SRF) activity, and sensors of body temperature rhythms, such as heat shock transcription factors and the cold-inducible RNA-binding protein CIRP. To study these systemic signalling pathways, we designed and engineered a novel, highly photosensitive apparatus, dubbed RT-Biolumicorder. This device enables us to record circadian luciferase reporter gene expression in the liver and other organs of freely moving mice over months in real time. Owing to the multitude of systemic signalling pathway involved in the phase resetting of peripheral clocks the disruption of any particular one has only minor effects on the steady state phase of circadian gene expression in organs such as the liver. Nonetheless, the implication of specific pathways in the synchronization of clock gene expression can readily be assessed by monitoring the phase-shifting kinetics using the RT-Biolumicorder.
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Affiliation(s)
- A Gerber
- Department of Molecular Biology, University of Geneva, Geneva, Switzerland
- Laboratory of Biochemistry and Molecular Biology, Rockefeller University, New York, NY, USA
| | - C Saini
- Department of Molecular Biology, University of Geneva, Geneva, Switzerland
- Laboratory of Circadian Endocrinology, Geneva University Hospitals, Geneva, Switzerland
| | - T Curie
- Center of Integrative Genomics, University of Lausanne, Lausanne, Switzerland
| | - Y Emmenegger
- Center of Integrative Genomics, University of Lausanne, Lausanne, Switzerland
| | - G Rando
- Department of Molecular Biology, University of Geneva, Geneva, Switzerland
| | - P Gosselin
- Department of Molecular Biology, University of Geneva, Geneva, Switzerland
| | - I Gotic
- Department of Molecular Biology, University of Geneva, Geneva, Switzerland
| | - P Gos
- Department of Molecular Biology, University of Geneva, Geneva, Switzerland
| | - P Franken
- Center of Integrative Genomics, University of Lausanne, Lausanne, Switzerland
| | - U Schibler
- Department of Molecular Biology, University of Geneva, Geneva, Switzerland
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Saini C, Suter DM, Liani A, Gos P, Schibler U. The mammalian circadian timing system: synchronization of peripheral clocks. Cold Spring Harb Symp Quant Biol 2011; 76:39-47. [PMID: 22179985 DOI: 10.1101/sqb.2011.76.010918] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Mammalian physiology has to adapt to daily alternating periods during which animals either forage and feed or sleep and fast. The adaptation of physiology to these oscillations is controlled by a circadian timekeeping system, in which a master pacemaker in the suprachiasmatic nucleus (SCN) synchronizes slave clocks in peripheral organs. Because the temporal coordination of metabolism is a major purpose of clocks in many tissues, it is important that metabolic and circadian cycles are tightly coordinated. Recent studies have revealed a multitude of signaling components that possibly link metabolism to circadian gene expression. Owing to this redundancy, the implication of any single signaling pathway in the synchronization of peripheral oscillators cannot be assessed by determining the steady-state phase, but instead requires the monitoring of phase-shifting kinetics at a high temporal resolution.
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Affiliation(s)
- C Saini
- Department of Molecular Biology and National CCR Frontiers in Genetics, Sciences III, University of Geneva, 1211 Geneva-4, Switzerland
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11
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Kornmann B, Schaad O, Reinke H, Saini C, Schibler U. Regulation of circadian gene expression in liver by systemic signals and hepatocyte oscillators. Cold Spring Harb Symp Quant Biol 2007; 72:319-330. [PMID: 18419289 DOI: 10.1101/sqb.2007.72.041] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The mammalian circadian timing system has a hierarchical structure, in that a master pacemaker located in the suprachiasmatic nuclei (SCN) coordinates slave oscillators present in virtually all body cells. In both the SCN and peripheral organs, the rhythm-generating oscillators are self-sustained and cell-autonomous, and it is likely that the molecular makeup of master and slave oscillators is nearly identical. However, due to variations in period length, the phase coherence between peripheral oscillators in intact animals must be established by daily signals emanating directly or indirectly from the SCN master clock. The synchronization of individual cellular clocks in peripheral organs is probably accomplished by immediate-early genes that interpret the cyclic systemic signals and convey this phase information to core clock components. This model predicts that circadian gene expression in peripheral organs can be influenced either by systemic signals emanating from the SCN master clock, local oscillators, or both. We developed a transgenic mouse strain in which hepatocyte clocks are only operative when the tetracycline analog doxycycline is added to the food or drinking water. The genome-wide mapping of genes whose cyclic expression in liver does not depend on functional hepatocyte oscillators unveiled putative signaling pathways that may participate in the phase entrainment of peripheral clocks.
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Affiliation(s)
- B Kornmann
- Department of Molecular Biology, University of Geneva 30, CH-1211 Geneva-4, Switzerland
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Slingsby R, Pohl C, Saini C. Approaches to sample pretreatment in the determination of perchlorate in real world samples. Anal Chim Acta 2006; 567:57-65. [PMID: 17723379 DOI: 10.1016/j.aca.2006.01.043] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2005] [Revised: 01/09/2006] [Accepted: 01/11/2006] [Indexed: 10/25/2022]
Abstract
Perchlorate can be determined by the tandem technique of ion chromatography (IC) coupled to electrospray ionization mass spectrometry (ESI-MS). However, detection by ESI-MS can be compromised by the coelution of matrix components that can suppress the analyte signal. In addition, the presence of surface-active and other types of matrix components can cause fouling of the electrospray inlet, reducing overall signal and requiring frequent maintenance. The influences of matrix components can be minimized by using analytical columns with different selectivities, in-line diversion of separated matrix components, and off-line selective removal of matrix components via ion exchange or adsorption. This paper will discuss these sample preparation approaches for samples containing anionic species including surfactants and inorganic ions that elute in the vicinity of perchlorate.
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Affiliation(s)
- R Slingsby
- Dionex Corporation, 445 Lakeside Drive, Sunnyvale, CA, USA.
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Abstract
US Environmental Protection Agency Method 300.0 specifies the use of an IonPac AS4A anion-exchange column with a carbonate-hydrogencarbonate eluent and suppressed conductivity detection for the determination of inorganic anions in environmental waters by ion chromatography. Hydroxide eluents have not typically been used for the routine analysis of common inorganic anions due to the lack of an appropriate hydroxide selective column and the difficulty in preparing contaminant free hydroxide eluents. The use of ion chromatography with a hydroxide-selective IonPac AS17 column, automated eluent generation and potassium hydroxide gradient represents a new approach to the routine determination of inorganic anions in environmental waters. This new approach, which is a modification of Method 300.0, allows equivalent method performance with improved linearity, precision, and method detection limits. The AS17 column provides superior retention of fluoride from the column void volume and improved resolution from small organic acids, such as formate and acetate, compared to the AS4A column. Quantitative recoveries were obtained for all the common inorganic anions spiked into typical environmental waters using this new approach, and the Performance Based Measurement System Tier 1 method validation quality control acceptance criteria are well within the acceptable ranges defined by Method 300.0. In addition, the EG40 eluent generator eliminates the need to manually prepare eluents, increasing the level of automation and ease-of-use of the ion chromatography system.
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Affiliation(s)
- P E Jackson
- Dionex Corporation, Sunnyvale, CA 94088-3606, USA
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Casagrande C, Santangelo F, Saini C, Doggi F, Gerli F, Cerri O. Synthesis and chemical properties of ibopamine and of related esters of N-substituted dopamines--synthesis of ibopamine metabolites. Arzneimittelforschung 1986; 36:291-303. [PMID: 3707640] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The therapeutic usefulness of intravenously infused dopamine in congestive heart failure and in shock prompted us to synthesize a wide series of 3,4-O-diesters of dopamine and N-substituted derivatives to obtain an orally active dopamine-like prodrug having adequate absorption and duration of action. The pharmacological results and in particular, the hemodynamic studies in the dog led to the selection of ibopamine, i.e. the 3,4-diisobutyryl ester of N-methyldopamine and to its development as a useful drug for the chronic treatment of congestive heart failure. The choice of ibopamine from among several analogs was also influenced by other favourable properties such as good chemical stability in pharmaceutical formulations and in the biopharmaceutical phases of the absorption, and fast enzymatic activation of the prodrug by plasma and peripheral tissue esterases; the latter property appeared desirable to avoid any accumulation in the central nervous system and consequent undesired side effects. The isomeric mixture of 3-O- and 4-O-isobutyrates of N-methyldopamine as well as the main conjugated metabolites, i.e. the 3-O- and 4-O-sulphate and 4-O-beta-glucuronide of N-methyldopamine were synthesized as analytical references in metabolic studies and for the investigation on their pharmacokinetic and pharmacological properties. Dopamine O-sulphates were also prepared using the methods developed for the corresponding N-methyl derivatives.
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