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Nejthardt MB, Alexandris P, Bechan S, Bijli MFA, Chetty S, Dippenaar JM, Gibbs M, Johnson M, Kluyts H, Llewellyn R, Motiang M, Mogane P, Motshabi P, Mrara B, Roodt F, Singh U, Spijkerman S, Turton E, Van der Westhuizen J, Biccard B. The development of a nurse-led preoperative anaesthesia screening tool by Delphi consensus. S Afr Med J 2024; 114:e1306. [PMID: 38525581 DOI: 10.7196/samj.2024.v114i2.1306] [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: 07/23/2023] [Indexed: 03/26/2024] Open
Abstract
BACKGROUND Low- and middle-income countries have a critical shortage of specialist anaesthetists. Most patients arriving for surgery are of low perioperative risk. Without immediate access to preoperative specialist care, an appropriate interim strategy may be to ensure that only high-risk patients are seen preoperatively by a specialist. Matching human resources to the burden of disease with a nurse-administered pre-operative screening tool to identify high-risk patients who might benefit from specialist review prior to the day of surgery may be an effective strategy. OBJECTIVE To develop a nurse-administered preoperative anaesthesia screening tool to identify patients who would most likely benefit from a specialist review before the day of surgery, and those patients who could safely be seen by the anaesthetist on the day of surgery. This would ensure adequate time for optimisation of high-risk patients preoperatively and limit avoidable day-of-surgery cancellations. METHODS A systematic review was conducted to identify preoperative screening questions for use in a three-round Delphi consensus process. A panel of 16 experienced full-time clinical anaesthetists representing all university-affiliated anaesthesia departments in South Africa participated to define a nurses' screening tool for preoperative assessment. RESULTS Ninety-eight studies were identified, which generated 79 questions. An additional 14 items identified by the facilitators were added to create a list of 93 questions for the first round. The final screening tool consisted of 81 questions, of which 37 were deemed critical to identify patients who should be seen by a specialist prior to the day of surgery. CONCLUSION A structured nurse-administered preoperative screening tool is proposed to identify high-risk patients who are likely to benefit from a timely preoperative specialist anaesthetist review to avoid cancellation on the day of surgery.
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Affiliation(s)
- M B Nejthardt
- Department of Anaesthesia and Perioperative Medicine, Faculty of Health Sciences, University of Cape Town, South Africa; Department of Anaesthesia and Perioperative Medicine, Groote Schuur Hospital, Cape Town, South Africa.
| | - P Alexandris
- Department of Anaesthesia, Faculty of Health Sciences, Nelson Mandela University, Gqeberha, South Africa.
| | - S Bechan
- Discipline of Anaesthesiology and Critical Care, Nelson R Mandela School of Medicine, University of Kwa-Zulu Natal, Albert Luthuli Academic Hospital, Durban, South Africa.
| | - M F A Bijli
- Department of Anaesthesia and Perioperative Medicine, Faculty of Health Sciences, University of Cape Town, South Africa.
| | - S Chetty
- Department of Anaesthesia and Critical Care, Stellenbosch University and Tygerberg Hospital, Cape Town, South Africa.
| | - J M Dippenaar
- Department of Anaesthesiology, Steve Biko Academic Hospital, University of Pretoria, South Africa.
| | - M Gibbs
- Department of Anaesthesia and Perioperative Medicine, Faculty of Health Sciences, University of Cape Town, South Africa; Department of Anaesthesia and Perioperative Medicine, Groote Schuur Hospital, Cape Town, South Africa.
| | - M Johnson
- Department of Anaesthesia and Critical Care, Stellenbosch University and Tygerberg Hospital, Cape Town, South Africa.
| | - H Kluyts
- Department of Anaesthesiology and Critical Care, Sefako Makgatho Health Sciences University, Pretoria, South Africa.
| | - R Llewellyn
- Department of Anaesthesia and Perioperative Medicine, Faculty of Health Sciences, University of Cape Town, South Africa; Department of Anaesthesia and Perioperative Medicine, Groote Schuur Hospital, Cape Town, South Africa.
| | - M Motiang
- Department of Anaesthesiology and Critical Care, Sefako Makgatho Health Sciences University, Pretoria, South Africa.
| | - P Mogane
- Department of Anaesthesiology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa; Department of Anaesthesia, Chris Hani Baragwanath Hospital, Soweto, South Africa.
| | - P Motshabi
- Department of Anaesthesiology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa; Department of Anaesthesia, Charlotte Maxeke Hospital, Johannesburg, South Africa.
| | - B Mrara
- Department of Anaesthesia and Critical Care, Nelson Mandela Academic Hospital, Walter Sisulu University, Mthatha, South Africa.
| | - F Roodt
- Department of Anaesthesia and Perioperative Medicine, Faculty of Health Sciences, University of Cape Town, South Africa; George Provincial Hospital, George, South Africa.
| | - U Singh
- Discipline of Anaesthesiology and Critical Care, Nelson R Mandela School of Medicine, University of Kwa-Zulu Natal, Albert Luthuli Academic Hospital, Durban, South Africa.
| | - S Spijkerman
- Department of Anaesthesiology, Steve Biko Academic Hospital, University of Pretoria, South Africa.
| | - E Turton
- Department of Anaesthesia, University of the Free State, Universitas Hospital, Bloemfontein, South Africa.
| | - J Van der Westhuizen
- Department of Anaesthesia, University of the Free State, Universitas Hospital, Bloemfontein, South Africa.
| | - B Biccard
- Department of Anaesthesia and Perioperative Medicine, Faculty of Health Sciences, University of Cape Town, South Africa; Department of Anaesthesia and Perioperative Medicine, Groote Schuur Hospital, Cape Town, South Africa.
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Rossouw E, Chetty S. Acute kidney injury after major non-cardiac surgery: Incidence and risk factors. S Afr Med J 2023; 113:135-140. [PMID: 36876351 DOI: 10.7196/samj.2023.v113i3.16783] [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: 03/02/2023] [Indexed: 03/06/2023] Open
Abstract
BACKGROUND Acute kidney injury (AKI) is a major post-surgical complication that contributes to morbidity and mortality. AKI is welldocumented after cardiac surgery. However, less is known regarding the incidence and risk factors following major non-cardiac surgery.Globally the incidence of AKI post major surgery has been evaluated; however, there are no data available for South Africa (SA). OBJECTIVES To ascertain the incidence of AKI after major non-cardiac surgery at a tertiary academic SA hospital. Secondary outcomes wereto identify perioperative risk factors that are associated with an elevated risk to develop AKI in the postoperative period. METHODS The study was conducted at Tygerberg Hospital, a single tertiary centre in Cape Town, SA. Perioperative records of adults whounderwent major non-cardiac surgery were retrospectively collected. Variables pertaining to potential risk factors for AKI were captured,and serum creatinine levels were recorded up to 7 days postoperatively and compared with baseline measurements to determine whetherAKI had developed. Descriptive statistics along with logistic regression analysis were used to interpret results. RESULTS The overall incidence of AKI was 11.2% (95% confidence interval (CI) 9.8 - 12.6). Based on surgical discipline, trauma surgery(19%), followed by abdominal (18.5%) and vascular surgery (17%) had the highest incidence. Independent AKI risk factors wereidentified after multivariate analysis. These were: chronic obstructive pulmonary disease (odds ratio (OR) 2.19; 95% CI 1.09 - 4.37;p=0.005), trauma surgery (OR 3.00; 95% CI 1.59 - 5.64; p=0.001), abdominal surgery (OR 2.14; 95% CI 1.33 - 3.45; p=0.002), vascularsurgery (OR 2.42; 95% CI 1.31 - 4.45; p=0.004), urology procedures (OR 2.45; 95% CI 1.31 - 4.45; p=0.005), red blood cell transfusion(OR 1.81; 95% CI 1.21 - 2.70; p=0.004), emergency surgery (OR 1.74; 95% CI 1.15 - 2.65; p=0.009) and inotrope use (OR 2.77; 95% CI1.80 - 4.26; p<0.001). CONCLUSION The results of our study are in keeping with international literature regarding the incidence of AKI after major non-cardiacsurgery. The risk factor profile, however, is in several regards different from what has been found elsewhere.
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Affiliation(s)
- E Rossouw
- Department of Anaesthesiology and Critical Care, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa.
| | - S Chetty
- Department of Anaesthesiology and Critical Care, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa.
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Abstract
Oligodendrocyte progenitor cells (OPCs) and mature oligodendrocytes (OLs) can be generated using human induced pluripotent stem cells (hiPSCs) and human embryonic stem cells (hESCs). By manipulating culture conditions, pluripotent cell types are serially guided through intermediary cell types, developing first into neural progenitor cells (NPCs) then OPCs before maturing as CNS-specific OLs. This procedure is conducted under adherent, feeder-free conditions to derive mature OLs in as few as 28 days.
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Affiliation(s)
- Zoe Mattingly
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, MA, USA
| | - Sundari Chetty
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, MA, USA.
- Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
- Harvard Stem Cell Institute, Cambridge, MA, USA.
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Louw K, Naidoo R, Chetty S. Radiation exposure of anaesthesia providers in Africa: an occupational exposure study. Southern African Journal of Anaesthesia and Analgesia 2022. [DOI: 10.36303/sajaa.2022.28.2.2673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- K Louw
- Department of Anaesthesiology and Critical Care, Faculty of Medicine and Health Sciences, Stellenbosch University,
South Africa
| | - R Naidoo
- Department of Anaesthesiology and Critical Care, Faculty of Medicine and Health Sciences, Stellenbosch University,
South Africa
| | - S Chetty
- Department of Anaesthesiology and Critical Care, Faculty of Medicine and Health Sciences, Stellenbosch University,
South Africa
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Isa AS, Chetty S. Physiology and pathophysiology of chronic pain (Part II): how does pain become chronic? Southern African Journal of Anaesthesia and Analgesia 2022. [DOI: 10.36303/sajaa.2022.28.1.2497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- AS Isa
- Department of Anaesthesiology and Critical Care, Faculty of Medicine and Health Sciences, Stellenbosch University,
South Africa
- Department of Human Physiology, Faculty of Basic Medical Sciences, College of Medical Sciences, Ahmadu Bello University,
Nigeria
| | - S Chetty
- Department of Anaesthesiology and Critical Care, Faculty of Medicine and Health Sciences, Stellenbosch University,
South Africa
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Pluvinage JV, Sun J, Claes C, Flynn RA, Haney MS, Iram T, Meng X, Lindemann R, Riley NM, Danhash E, Chadarevian JP, Tapp E, Gate D, Kondapavulur S, Cobos I, Chetty S, Pașca AM, Pașca SP, Berry-Kravis E, Bertozzi CR, Blurton-Jones M, Wyss-Coray T. The CD22-IGF2R interaction is a therapeutic target for microglial lysosome dysfunction in Niemann-Pick type C. Sci Transl Med 2021; 13:eabg2919. [PMID: 34851695 PMCID: PMC9067636 DOI: 10.1126/scitranslmed.abg2919] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [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] [Indexed: 01/07/2023]
Abstract
Lysosome dysfunction is a shared feature of rare lysosomal storage diseases and common age-related neurodegenerative diseases. Microglia, the brain-resident macrophages, are particularly vulnerable to lysosome dysfunction because of the phagocytic stress of clearing dying neurons, myelin, and debris. CD22 is a negative regulator of microglial homeostasis in the aging mouse brain, and soluble CD22 (sCD22) is increased in the cerebrospinal fluid of patients with Niemann-Pick type C disease (NPC). However, the role of CD22 in the human brain remains unknown. In contrast to previous findings in mice, here, we show that CD22 is expressed by oligodendrocytes in the human brain and binds to sialic acid–dependent ligands on microglia. Using unbiased genetic and proteomic screens, we identify insulin-like growth factor 2 receptor (IGF2R) as the binding partner of sCD22 on human myeloid cells. Targeted truncation of IGF2R revealed that sCD22 docks near critical mannose 6-phosphate–binding domains, where it disrupts lysosomal protein trafficking. Interfering with the sCD22-IGF2R interaction using CD22 blocking antibodies ameliorated lysosome dysfunction in human NPC1 mutant induced pluripotent stem cell–derived microglia-like cells without harming oligodendrocytes in vitro. These findings reinforce the differences between mouse and human microglia and provide a candidate microglia-directed immunotherapeutic to treat NPC.
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Affiliation(s)
- John V. Pluvinage
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94304, USA
| | - Jerry Sun
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94304, USA
| | - Christel Claes
- Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA 92697, USA
| | - Ryan A. Flynn
- Stem Cell Program, Children’s Hospital Boston, Boston, MA 02115, USA
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02138, USA
| | - Michael S. Haney
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94304, USA
| | - Tal Iram
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94304, USA
| | - Xiangling Meng
- Stanford Brain Organogenesis, Wu Tsai Neurosciences Institute, Stanford University, Stanford, CA 94305, USA
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA 94304, USA
| | - Rachel Lindemann
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94304, USA
| | - Nicholas M. Riley
- Department of Chemistry and ChEM-H, Stanford University, Stanford, CA 94305, USA
- Howard Hughes Medical Institute, Stanford University, Stanford, CA 94304, USA
| | - Emma Danhash
- Sue and Bill Gross Stem Cell Research Center, University of California, Irvine, Irvine, CA 92697, USA
| | - Jean Paul Chadarevian
- Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA 92697, USA
- Sue and Bill Gross Stem Cell Research Center, University of California, Irvine, Irvine, CA 92697, USA
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, Irvine, CA 92697, USA
| | - Emma Tapp
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94304, USA
| | - David Gate
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94304, USA
| | - Sravani Kondapavulur
- Medical Scientist Training Program, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Inma Cobos
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94304, USA
| | - Sundari Chetty
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA 94304, USA
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Anca M. Pașca
- Division of Neonatology, Department of Pediatrics, Stanford University, Stanford, CA 94304, USA
| | - Sergiu P. Pașca
- Stanford Brain Organogenesis, Wu Tsai Neurosciences Institute, Stanford University, Stanford, CA 94305, USA
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA 94304, USA
| | | | - Carolyn R. Bertozzi
- Department of Chemistry and ChEM-H, Stanford University, Stanford, CA 94305, USA
- Howard Hughes Medical Institute, Stanford University, Stanford, CA 94304, USA
| | - Mathew Blurton-Jones
- Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA 92697, USA
- Sue and Bill Gross Stem Cell Research Center, University of California, Irvine, Irvine, CA 92697, USA
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, Irvine, CA 92697, USA
| | - Tony Wyss-Coray
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94304, USA
- Paul F. Glenn Center for the Biology of Aging, Stanford University School of Medicine, Stanford, CA 94304, USA
- Wu Tsai Neurosciences Institute, Stanford, CA, 94305, USA
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7
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Isa AS, Chetty S. Physiology and pathophysiology of chronic pain (Part I). Southern African Journal of Anaesthesia and Analgesia 2021. [DOI: 10.36303/sajaa.2021.27.6.2491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- AS Isa
- Department of Anaesthesiology and Critical Care, Faculty of Medicine and Health Sciences, Stellenbosch University,
South Africa
- Department of Human Physiology, Faculty of Basic Medical Sciences, College of Medical Sciences, Ahmadu Bello University,
Nigeria
| | - S Chetty
- Department of Anaesthesiology and Critical Care, Faculty of Medicine and Health Sciences, Stellenbosch University,
South Africa
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9
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Ma L, Shcherbina A, Chetty S. Variations and expression features of CYP2D6 contribute to schizophrenia risk. Mol Psychiatry 2021; 26:2605-2615. [PMID: 32047265 PMCID: PMC8440189 DOI: 10.1038/s41380-020-0675-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Revised: 01/27/2020] [Accepted: 01/30/2020] [Indexed: 12/18/2022]
Abstract
Genome-wide association studies (GWAS) have successfully identified 145 loci implicated in schizophrenia (SCZ). However, the underlying mechanisms remain largely unknown. Here, we analyze 1497 RNA-seq data in combination with their genotype data and identify SNPs that are associated with expression throughout the genome by dissecting expression features to genes (eGene) and exon-exon junctions (eJunction). Then, we colocalize eGene and eJunction with SCZ GWAS using SMR and fine mapping. Multiple ChIP-seq data and DNA methylation data generated from brain were used for identifying the causal variants. Finally, we used a hypothesis-free (no SCZ risk loci considered) enrichment analysis to determine implicated pathways. We identified 171 genes and eight splicing junctions located within four genes (SNX19, ARL6IP4, APOPT1, and CYP2D6) that potentially contribute to SCZ susceptibility. Among the genes, CYP2D6 is significantly associated with SCZ SNPs in eGene and eJunction. In-depth examination of the CYP2D6 region revealed that a nonsynonymous single nucleotide variant rs16947 is strongly associated with a higher abundance of CYP2D6 exon 3 skipping junctions. While we found rs133377 and other functional SNPs in high linkage disequilibrium with rs16947 (r2 = 0.9539), histone acetylation analysis showed they are located within active transcription start sites. Furthermore, our data-driven enrichment analysis showed that CYP2D6 is significantly involved in drug metabolism of codeine, tamoxifen, and citalopram. Our study facilitates an understanding of the genetic architecture of SCZ and provides new drug targets.
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Affiliation(s)
- Liang Ma
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA, 94305, USA.
| | - Anna Shcherbina
- grid.168010.e0000000419368956Department of Biomedical Informatics, Stanford University, Stanford, CA 94305 USA
| | - Sundari Chetty
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA, 94305, USA. .,Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA, 94305, USA.
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10
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Scribante J, Perrie H, Chetty S. How knowledgeable is the recovery room nurse you entrust your patient to about postoperative airway emergencies? Southern African Journal of Anaesthesia and Analgesia 2021. [DOI: 10.36303/sajaa.2021.27.3.2475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- J Scribante
- Department of Anaesthesiology, School of Clinical Medicine, Faculty of Health Sciences, University of the Witwatersrand,
South Africa
| | - H Perrie
- Department of Anaesthesiology, School of Clinical Medicine, Faculty of Health Sciences, University of the Witwatersrand,
South Africa
| | - S Chetty
- Department of Anaesthesiology and Critical Care, Faculty of Medicine and Health Sciences, Stellenbosch University,
South Africa
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11
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Assetta B, Tang C, Bian J, O'Rourke R, Connolly K, Brickler T, Chetty S, Huang YWA. Generation of Human Neurons and Oligodendrocytes from Pluripotent Stem Cells for Modeling Neuron-Oligodendrocyte Interactions. J Vis Exp 2020. [PMID: 33226027 DOI: 10.3791/61778] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
In Alzheimer's disease (AD) and other neurodegenerative disorders, oligodendroglial failure is a common early pathological feature, but how it contributes to disease development and progression, particularly in the gray matter of the brain, remains largely unknown. The dysfunction of oligodendrocyte lineage cells is hallmarked by deficiencies in myelination and impaired self-renewal of oligodendrocyte precursor cells (OPCs). These two defects are caused at least in part by the disruption of interactions between neuron and oligodendrocytes along the buildup of pathology. OPCs give rise to myelinating oligodendrocytes during CNS development. In the mature brain cortex, OPCs are the major proliferative cells (comprising ~5% of total brain cells) and control new myelin formation in a neural activity-dependent manner. Such neuron-to-oligodendrocyte communications are significantly understudied, especially in the context of neurodegenerative conditions such as AD, due to the lack of appropriate tools. In recent years, our group and others have made significant progress to improve currently available protocols to generate functional neurons and oligodendrocytes individually from human pluripotent stem cells. In this manuscript, we describe our optimized procedures, including the establishment of a co-culture system to model the neuron-oligodendrocyte connections. Our illustrative results suggest an unexpected contribution from OPCs/oligodendrocytes to the brain amyloidosis and synapse integrity and highlight the utility of this methodology for AD research. This reductionist approach is a powerful tool to dissect the specific hetero-cellular interactions out of the inherent complexity inside the brain. The protocols we describe here are expected to facilitate future studies on oligodendroglial defects in the pathogenesis of neurodegeneration.
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Affiliation(s)
- Benedetta Assetta
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University
| | - Changyong Tang
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University; Department of Neurology, The Third Affiliated Hospital of Sun Yat-Sen University
| | - Jing Bian
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine
| | - Ryan O'Rourke
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University
| | - Kevin Connolly
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University
| | - Thomas Brickler
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine
| | - Sundari Chetty
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine; Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine
| | - Yu-Wen Alvin Huang
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University; Department of Neurology, Warren Alpert Medical School of Brown University; Center for Translational Neuroscience, Robert J. and Nancy D. Carney Institute for Brain Science and Brown Institute for Translational Science, Brown University;
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12
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Joynt GM, Gopalan PD, Argent A, Chetty S, Wise R, Lai VKW, Hodgson E, Lee A, Joubert I, Mokgokong S, Tshukutsoane S, Richards GA, Menezes C, Mathivha LR, Espen B, Levy B, Asante K, Paruk F. The Critical Care Society of Southern Africa Consensus Guideline on ICU Triage and Rationing (ConICTri). South Afr J Crit Care 2019; 35:10.7196/SAJCC.2019.v35i1b.380. [PMID: 37719328 PMCID: PMC10503493 DOI: 10.7196/sajcc.2019.v35i1b.380] [Citation(s) in RCA: 1] [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] [Accepted: 07/01/2019] [Indexed: 11/08/2022] Open
Abstract
Background In South Africa (SA), administrators and intensive care practitioners are faced with the challenge of resource scarcity as well as an increasing demand for intensive care unit (ICU) services. ICU services are expensive, and practitioners in low- to middle-income countries experience the consequences of limited resources daily. Critically limited resources necessitate that rationing and triage (prioritisation) decisions are routinely necessary in SA, particularly in the publicly funded health sector. Purpose The purpose of this guideline is to utilise the relevant recommendations of the associated consensus meeting document and other internationally accepted principles to develop a guideline to inform frontline triage policy and ensure the best utilisation of adult intensive care in SA, while maintaining the fair distribution of available resources. Recommendations An overall conceptual framework for the triage process was developed. The components of the framework were developed on the basis that patients should be admitted preferentially when the likely incremental medical benefit derived from ICU admission justifies admission. An estimate of likely resource use should also form part of the triage decision, with those patients requiring relatively less resources to achieve substantial benefit receiving priority for admission. Thus, the triage system should maximise the benefits obtained from ICU resources available for the community. Where possible, practical examples of what the consensus group agreed would be considered appropriate practice under specified South African circumstances were provided, to assist clinicians with practical decision-making. It must be stressed that this guideline is not intended to be prescriptive for individual hospital or regional practice, and hospitals and regions are encouraged to develop specified local guidelines with locally relevant examples. The guideline should be reviewed and revised if appropriate within 5 years. Conclusion In recognition of the absolute need to limit patient access to ICU because of the lack of sufficient intensive care resources in public hospitals, this guideline has been developed to guide policy-making and assist frontline triage decision-making in SA. This document is not a complete plan for quality practice, but rather a template to support frontline clinicians, guide administrators and inform the public regarding appropriate triage decision-making.
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Affiliation(s)
- G M Joynt
- Department of Anaesthesia and Intensive Care, The Chinese University of Hong Kong, Hong Kong
| | - P D Gopalan
- Department of Anaesthesiology and Critical Care, School of Clinical Medicine, University of KwaZulu-Natal, Durban, South Africa
| | - A Argent
- Department of Paediatrics and Child Health, University of Cape Town, South Africa
| | - S Chetty
- Department of Anaesthesiology and Critical Care, Stellenbosch University, Cape Town, South Africa
| | - R Wise
- Department of Anaesthesiology and Critical Care, School of Clinical Medicine, University of KwaZulu-Natal, Durban, and Edendale Hospital,
Pietermaritzburg, South Africa
| | - V K W Lai
- Department of Anaesthesia and Intensive Care, The Chinese University of Hong Kong, Hong Kong
| | - E Hodgson
- Department of Anaesthesiology and Critical Care, School of Clinical Medicine, University of KwaZulu-Natal, Durban, and Inkosi Albert Luthuli
Central Hospital, Durban, South Africa
| | - A Lee
- Department of Anaesthesia and Intensive Care, The Chinese University of Hong Kong, Hong Kong
| | - I Joubert
- Department of Anaesthesia and Peri-operative Medicine, University of Cape Town and Groote Schuur Hospital, Cape Town, South Africa
| | - S Mokgokong
- Department of Neurosurgery, University of Pretoria, South Africa
| | - S Tshukutsoane
- Chris Hani Baragwanath Academic Hospital, Soweto, Johannesburg, South Africa
| | - G A Richards
- Department of Critical Care, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - C Menezes
- Chris Hani Baragwanath Academic Hospital, Soweto, Johannesburg, South Africa
- Department of Critical Care, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - L R Mathivha
- Department of Critical Care, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - B Espen
- Centre for Health Professions Education, Stellenbosch University, Cape Town, South Africa
| | - B Levy
- Netcare Rosebank Hospital, Johannesburg, South Africa
| | - K Asante
- African Organization for Research and Training in Cancer, Cape Town, South Africa
| | - F Paruk
- Department of Critical Care, University of Pretoria, South Africa
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13
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Joynt GM, Gopalan PD, Argent A, Chetty S, Wise R, Lai VKW, Hodgson E, Lee A, Joubert I, Mokgokong S, Tshukutsoane S, Richards GA, Menezes C, Mathivha LR, Espen B, Levy B, Asante K, Paruk F. The Critical Care Society of Southern Africa Consensus Statement on ICU Triage and Rationing (ConICTri). South Afr J Crit Care 2019; 35:10.7196/SAJCC.2019.v35.i1b.383. [PMID: 37719327 PMCID: PMC10503494 DOI: 10.7196/sajcc.2019.v35.i1b.383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/01/2019] [Indexed: 09/19/2023] Open
Abstract
Background In South Africa (SA), intensive care is faced with the challenge of resource scarcity as well as an increasing demand for intensive care unit (ICU) services. ICU services are expensive, and practitioners in low- to middle-income countries experience daily the consequences of limited resources. Critically limited resources necessitate that rationing and triage (prioritisation) decisions are frequently necessary in SA, particularly in the publicly funded health sector. Purpose The purpose of this consensus statement is to examine key questions that arise when considering the status of ICU resources in SA, and more specifically ICU admission, rationing and triage decisions. The accompanying guideline in this issue is intended to guide frontline triage policy and ensure the best utilisation of intensive care in SA, while maintaining a fair distribution of available resources. Fair and efficient triage is important to ensure the ongoing provision of high-quality care to adult patients referred for intensive care. Recommendations In response to 14 key questions developed using a modified Delphi technique, 29 recommendations were formulated and graded using an adapted GRADE score. The 14 key questions addressed the status of the provision of ICU services in SA, the degree of resource restriction, the efficiency of resource management, the need for triage, and how triage could be most justly implemented. Important recommendations included the need to formally recognise and accurately quantify the provision of ICU services in SA by national audit; actively seek additional resources from governmental bodies; consider methods to maximise the efficiency of ICU care; evaluate lower level of care alternatives; develop a triage guideline to assist policy-makers and frontline practitioners to implement triage decisions in an efficient and fair way; measure and audit the consequence of triage; and promote research to improve the accuracy and consistency of triage decisions. The consensus document and guideline should be reviewed and revised appropriately within 5 years. Conclusion In recognition of the absolute need to limit patient access to ICU because of the lack of sufficient intensive care resources in public hospitals, recommendations and a guideline have been developed to guide policy-making and assist frontline triage decision-making in SA. These documents are not a complete plan for quality practice but rather the beginning of a long-term initiative to engage clinicians, the public and administrators in appropriate triage decision-making, and promote systems that will ultimately maximise the efficient and fair use of available ICU resources.
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Affiliation(s)
- G M Joynt
- Department of Anaesthesia and Intensive Care, The Chinese University of Hong Kong, Hong Kong
| | - P D Gopalan
- Department of Anaesthesiology and Critical Care, School of Clinical Medicine, University of KwaZulu-Natal, Durban, South Africa
| | - A Argent
- Department of Paediatrics and Child Health, University of Cape Town, South Africa
| | - S Chetty
- Department of Anaesthesiology and Critical Care, Stellenbosch University, Cape Town, South Africa
| | - R Wise
- Department of Anaesthesiology and Critical Care, School of Clinical Medicine, University of KwaZulu-Natal, Durban, and Edendale Hospital,
Pietermaritzburg, South Africa
| | - V K W Lai
- Department of Anaesthesia and Intensive Care, The Chinese University of Hong Kong, Hong Kong
| | - E Hodgson
- Department of Anaesthesiology and Critical Care, School of Clinical Medicine, University of KwaZulu-Natal, Durban, and Inkosi Albert Luthuli
Central Hospital, Durban, South Africa
| | - A Lee
- Department of Anaesthesia and Intensive Care, The Chinese University of Hong Kong, Hong Kong
| | - I Joubert
- Department of Anaesthesia and Peri-operative Medicine, University of Cape Town and Groote Schuur Hospital, Cape Town, South Africa
| | - S Mokgokong
- Department of Neurosurgery, University of Pretoria, South Africa
| | - S Tshukutsoane
- Chris Hani Baragwanath Academic Hospital, Soweto, Johannesburg, South Africa
| | - G A Richards
- Department of Critical Care, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - C Menezes
- Chris Hani Baragwanath Academic Hospital, Soweto, Johannesburg, South Africa
- Department of Critical Care, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - L R Mathivha
- Department of Critical Care, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - B Espen
- Centre for Health Professions Education, Stellenbosch University, Cape Town, South Africa
| | - B Levy
- Netcare Rosebank Hospital, Johannesburg, South Africa
| | - K Asante
- African Organization for Research and Training in Cancer, Cape Town, South Africa
| | - F Paruk
- Department of Critical Care, University of Pretoria, South Africa
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Abstract
Despite the growing use of pluripotent stem cells (PSCs), challenges in efficiently differentiating embryonic and induced pluripotent stem cells (ESCs and iPSCs) across various lineages remain. Numerous differentiation protocols have been developed, yet variability across cell lines and low rates of differentiation impart challenges in successfully implementing these protocols. Described here is an easy and inexpensive means to enhance the differentiation capacity of PSCs. It has been previously shown that treatment of stem cells with a low concentration of dimethyl sulfoxide (DMSO) significantly increases the propensity of a variety of PSCs to differentiate to different cell types following directed differentiation. This technique has now been shown to be effective across different species (e.g., mouse, primate, and human) into multiple lineages, ranging from neurons and cortical spheroids to smooth muscle cells and hepatocytes. The DMSO pretreatment improves PSC differentiation by regulating the cell cycle and priming stem cells to be more responsive to differentiation signals. Provided here is the detailed methodology for using this simple tool as a reproducible and widely applicable means to more efficiently differentiate PSCs to any lineage of choice.
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Affiliation(s)
- Danielle Sambo
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine
| | - Jingling Li
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine
| | - Thomas Brickler
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine
| | - Sundari Chetty
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine; Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine;
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15
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Shcherbina A, Li J, Narayanan C, Greenleaf W, Kundaje A, Chetty S. Brief Report: Cell Cycle Dynamics of Human Pluripotent Stem Cells Primed for Differentiation. Stem Cells 2019; 37:1151-1157. [PMID: 31135093 PMCID: PMC6711778 DOI: 10.1002/stem.3041] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Revised: 04/26/2019] [Accepted: 05/14/2019] [Indexed: 01/09/2023]
Abstract
Understanding the molecular properties of the cell cycle of human pluripotent stem cells (hPSCs) is critical for effectively promoting differentiation. Here, we use the Fluorescence Ubiquitin Cell Cycle Indicator system adapted into hPSCs and perform RNA sequencing on cell cycle sorted hPSCs primed and unprimed for differentiation. Gene expression patterns of signaling factors and developmental regulators change in a cell cycle‐specific manner in cells primed for differentiation without altering genes associated with pluripotency. Furthermore, we identify an important role for PI3K signaling in regulating the early transitory states of hPSCs toward differentiation. stem cells2019;37:1151–1157
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Affiliation(s)
- Anna Shcherbina
- Department of Biomedical Informatics, Stanford University, Stanford, California, USA
| | - Jingling Li
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, California, USA
| | - Cyndhavi Narayanan
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, California, USA
| | - William Greenleaf
- Department of Genetics, Stanford University, Stanford, California, USA
| | - Anshul Kundaje
- Department of Genetics, Stanford University, Stanford, California, USA.,Department of Computer Science, Stanford University, Stanford, California, USA
| | - Sundari Chetty
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, California, USA.,Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, California, USA
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16
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Li J, Narayanan C, Bian J, Sambo D, Brickler T, Zhang W, Chetty S. A transient DMSO treatment increases the differentiation potential of human pluripotent stem cells through the Rb family. PLoS One 2018; 13:e0208110. [PMID: 30540809 PMCID: PMC6291069 DOI: 10.1371/journal.pone.0208110] [Citation(s) in RCA: 13] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Accepted: 11/12/2018] [Indexed: 01/01/2023] Open
Abstract
The propensity for differentiation varies substantially across human pluripotent stem cell (hPSC) lines, greatly restricting the use of hPSCs for cell replacement therapy or disease modeling. Here, we investigate the underlying mechanisms and demonstrate that activation of the retinoblastoma (Rb) pathway in a transient manner is important for differentiation. In prior work, we demonstrated that pre-treating hPSCs with dimethylsulfoxide (DMSO) before directed differentiation enhanced differentiation potential across all three germ layers. Here, we show that exposure to DMSO improves the efficiency of hPSC differentiation through Rb and by repressing downstream E2F-target genes. While transient inactivation of the Rb family members (including Rb, p107, and p130) suppresses DMSO’s capacity to enhance differentiation across all germ layers, transient expression of a constitutively active (non-phosphorylatable) form of Rb increases the differentiation efficiency similar to DMSO. Inhibition of downstream targets of Rb, such as E2F signaling, also promotes differentiation of hPSCs. More generally, we demonstrate that the duration of Rb activation plays an important role in regulating differentiation capacity.
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Affiliation(s)
- Jingling Li
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, California, United States of America
| | - Cyndhavi Narayanan
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, California, United States of America
| | - Jing Bian
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, California, United States of America
| | - Danielle Sambo
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, California, United States of America
| | - Thomas Brickler
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, California, United States of America
| | - Wancong Zhang
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, California, United States of America
| | - Sundari Chetty
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, California, United States of America
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, California, United States of America
- * E-mail:
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17
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Mccloskey C, Mongan A, Chetty S, McAteer D, Quinn S. Aflibercept in neovascular age related macular degeneration previously refractory to standard intravitreal therapy: An Irish perspective to compare against international trends. Acta Ophthalmol 2017. [DOI: 10.1111/j.1755-3768.2017.01112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- C. Mccloskey
- Ophthalmology; Sligo General Hospital; Sligo Ireland
| | - A.M. Mongan
- Ophthalmology; Sligo General Hospital; Sligo Ireland
| | - S. Chetty
- Ophthalmology; Sligo General Hospital; Sligo Ireland
| | - D. McAteer
- Ophthalmology; Sligo General Hospital; Sligo Ireland
| | - S. Quinn
- Ophthalmology; Sligo General Hospital; Sligo Ireland
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18
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Chetty S, Paruk F, Kamerman P. Abstract PR191. Anesth Analg 2016. [DOI: 10.1213/01.ane.0000492590.47304.36] [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: 11/05/2022]
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19
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Chetty S, Engquist EN, Mehanna E, Lui KO, Tsankov AM, Melton DA. A Src inhibitor regulates the cell cycle of human pluripotent stem cells and improves directed differentiation. J Cell Biol 2015; 210:1257-68. [PMID: 26416968 PMCID: PMC4586752 DOI: 10.1083/jcb.201502035] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Driving human pluripotent stem cells (hPSCs) into specific lineages is an inefficient and challenging process. We show that a potent Src inhibitor, PP1, regulates expression of genes involved in the G1 to S phase transition of the cell cycle, activates proteins in the retinoblastoma family, and subsequently increases the differentiation propensities of hPSCs into all three germ layers. We further demonstrate that genetic suppression of Src regulates the activity of the retinoblastoma protein and enhances the differentiation potential of hPSCs across all germ layers. These positive effects extend beyond the initial germ layer specification and enable efficient differentiation at subsequent stages of differentiation.
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Affiliation(s)
- Sundari Chetty
- Department of Stem Cell and Regenerative Biology, Harvard Stem Cell Institute, Cambridge, MA 02138
| | - Elise N Engquist
- Department of Stem Cell and Regenerative Biology, Harvard Stem Cell Institute, Cambridge, MA 02138
| | - Elie Mehanna
- Department of Stem Cell and Regenerative Biology, Harvard Stem Cell Institute, Cambridge, MA 02138
| | - Kathy O Lui
- Department of Stem Cell and Regenerative Biology, Harvard Stem Cell Institute, Cambridge, MA 02138
| | - Alexander M Tsankov
- Department of Stem Cell and Regenerative Biology, Harvard Stem Cell Institute, Cambridge, MA 02138 Broad Institute of MIT and Harvard, Cambridge, MA 02142
| | - Douglas A Melton
- Department of Stem Cell and Regenerative Biology, Harvard Stem Cell Institute, Cambridge, MA 02138 Howard Hughes Medical Institute, Harvard University, Cambridge, MA 02138
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20
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Chetty S, Engquist E, Mehanna E, Lui K, Tsankov A, Melton D. A Src inhibitor regulates the cell cycle of human pluripotent stem cells and improves directed differentiation. J Exp Med 2015. [DOI: 10.1084/jem.21211oia91] [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: 11/04/2022] Open
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21
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Chetty S, Paruk F. Delirium knowledge and assessment by ICU practitioners in South Africa: results of a national survey. Crit Care 2015. [PMCID: PMC4471072 DOI: 10.1186/cc14562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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22
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Paruk F, Chetty S. Sedation practices in South African ICUs: results of a national survey. Crit Care 2015. [PMCID: PMC4470456 DOI: 10.1186/cc14577] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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23
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Chetty S, Baalbergen E, Bhigjee AI, Kamerman P, Ouma J, Raath R, Raff M, Salduker S. Clinical practice guidelines for management of neuropathic pain: expert panel recommendations for South Africa. S Afr Fam Pract (2004) 2014. [DOI: 10.1080/20786204.2013.10874323] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Affiliation(s)
- S Chetty
- Department of Anaesthesiology, School of Clinical Medicine, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg
| | - E Baalbergen
- Life Vincent Pallotti Rehabilitation Unit, Pinelands, Cape Town
| | - AI Bhigjee
- Department of Neurology, Nelson R Mandela School of Medicine, Mayville, University of KwaZulu-Natal, Durban
| | - P Kamerman
- Brain Function Research Group, School of Physiology, University of the Witwatersrand, Johannesburg
| | - J Ouma
- Department of Neurosurgery, University of the Witwatersrand, Johannesburg
| | - R Raath
- Jacaranda Hospital, Muckleneuk, Pretoria
| | - M Raff
- Christiaan Barnard Memorial Hospital, Cape Town
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24
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Affiliation(s)
- S Chetty
- Department of Anaesthesiology, University of the Witwatersrand
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25
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Raju R, Moodley SR, Jagarnath O, Chetty S, Shongwe B, Raju J. The migration of integrated library systems with special reference to the rollout of Unicorn in the province of KZN. South African Journal of Libraries and Information Science 2013. [DOI: 10.7553/73-2-1350] [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: 10/25/2022] Open
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26
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Chetty S, Pagliuca FW, Honore C, Kweudjeu A, Rezania A, Melton DA. A simple tool to improve pluripotent stem cell differentiation. Nat Methods 2013; 10:553-6. [PMID: 23584186 PMCID: PMC3694177 DOI: 10.1038/nmeth.2442] [Citation(s) in RCA: 142] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2012] [Accepted: 03/12/2013] [Indexed: 02/06/2023]
Abstract
We develop a method to overcome previously documented restrictions on the differentiation propensities of pluripotent stem cells. Culturing pluripotent stem cells in dimethylsulfoxide (DMSO) activates the retinoblastoma protein, increases the proportion of cells in the early G1 phase of the cell cycle, and subsequently improves their competency for directed differentiation into multiple lineages in more than 25 stem cell lines. DMSO treatment also promotes terminal differentiation into functional derivatives.
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Affiliation(s)
- Sundari Chetty
- Department of Stem Cell and Regenerative Biology, Harvard Stem Cell Institute, Cambridge, Massachusetts, USA
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27
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Chetty S, Shephard E, Bowers D, Darby M, Horsnell W, Chapman R, Williamson A. A pantothenate suxotroph of BCG rxpressing Gag confers enhanced HIV-specific immunogenicity compared to wildtype and perfingolysin expressing strains. Retrovirology 2012. [PMCID: PMC3441340 DOI: 10.1186/1742-4690-9-s2-p315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022] Open
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28
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Chetty S, Porichis F, Govender P, Zupkosky J, Pillay M, Walker B, Ndung’u T, Kaufmann D, Kasprowicz V. Co-infection with Mycobacterium tuberculosis impairs HIV-specific CD8+ and CD4+ T cell functionality. Int J Infect Dis 2012. [DOI: 10.1016/j.ijid.2012.05.061] [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: 11/15/2022] Open
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Bassett IV, Chetty S, Giddy J, Reddy S, Bishop K, Lu Z, Losina E, Freedberg KA, Walensky RP. Screening for acute HIV infection in South Africa: finding acute and chronic disease. HIV Med 2011; 12:46-53. [PMID: 20553336 DOI: 10.1111/j.1468-1293.2010.00850.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
BACKGROUND The yield of screening for acute HIV infection among general medical patients in resource-scarce settings remains unclear. Our objective was to evaluate the strategy of using pooled HIV plasma RNA to diagnose acute HIV infection in patients with negative or discordant rapid HIV antibody tests in Durban, South Africa. METHODS We prospectively enrolled patients with negative or discordant rapid HIV antibody tests from a routine HIV screening programme in an out-patient department in Durban with an HIV prevalence of 48%. Study participants underwent venipuncture for pooled qualitative HIV RNA, and, if this was positive, quantitative RNA, enzyme immunoassay and Western blot (WB). Patients with negative or indeterminate WB and positive quantitative HIV RNA were considered acutely infected. Those with chronic infection (positive RNA and WB) despite negative or discordant rapid HIV tests were considered to have had false negative rapid antibody tests. RESULTS Nine hundred and ninety-four participants were enrolled with either negative (n=976) or discordant (n=18) rapid test results. Eleven [1.1%; 95% confidence interval (CI) 0.6-2.0%] had acute HIV infection, and an additional 20 (2.0%; 95% CI 1.3-3.1%) had chronic HIV infection (false negative rapid test). CONCLUSIONS One per cent of out-patients with negative or discordant rapid HIV tests in Durban, South Africa had acute HIV infection readily detectable through pooled serum HIV RNA screening. Pooled RNA testing also identified an additional 2% of patients with chronic HIV infection. HIV RNA screening has the potential to identify both acute and chronic HIV infections that are otherwise missed by standard HIV testing algorithms.
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Affiliation(s)
- I V Bassett
- Division of General Medicine, Massachusetts General Hospital, Boston, MA, USA.
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30
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Chetty S. The do’s and don’ts of arginine supplementation. South African Journal of Clinical Nutrition 2010. [DOI: 10.1080/16070658.2010.11734265] [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: 10/21/2022]
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Batterman S, Chernyak S, Gouden Y, Hayes J, Robins T, Chetty S. PCBs in air, soil and milk in industrialized and urban areas of KwaZulu-Natal, South Africa. Environ Pollut 2009; 157:654-663. [PMID: 18838199 PMCID: PMC4365072 DOI: 10.1016/j.envpol.2008.08.015] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2008] [Revised: 08/13/2008] [Accepted: 08/14/2008] [Indexed: 05/25/2023]
Abstract
Information regarding polychlorinated biphenyls (PCBs) in environmental media in Africa is limited. This paper presents results of a monitoring program conducted in KwaZulu-Natal Province, South Africa designed to characterize levels, trends and sources of airborne PCBs. Particulate and vapor samples were sampled over the 2004-2005 period at three sites. The total PCB concentration averaged 128+/-47 pgm(-3), and levels were highest in winter. Tri- through hexa-congeners predominated, and the vapor fraction was predominant. Several tetra- through hexa-chlorinated congeners had levels comparable to those at urban sites in the northern hemisphere, but hepta- through deca-congeners resembled levels at background sites. PCB source areas, deduced using spatial and temporal patterns, compositional information and trajectory analyses, likely included local, regional and global sources. Soils at three rural sites showed high PCB concentrations, and milk from a local dairy showed PCB concentrations comparable to USA levels in year 2000.
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Affiliation(s)
- S Batterman
- Environmental Health Sciences, University of Michigan School of Public Health, 109 Observatory Street, Ann Arbor, MI 48109-2029, USA.
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32
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Solbakk AK, Fuhrmann Alpert G, Furst AJ, Hale LA, Oga T, Chetty S, Pickard N, Knight RT. Altered prefrontal function with aging: insights into age-associated performance decline. Brain Res 2008; 1232:30-47. [PMID: 18691562 DOI: 10.1016/j.brainres.2008.07.060] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2008] [Revised: 07/06/2008] [Accepted: 07/07/2008] [Indexed: 10/21/2022]
Abstract
We examined the effects of aging on visuo-spatial attention. Participants performed a bi-field visual selective attention task consisting of infrequent target and task-irrelevant novel stimuli randomly embedded among repeated standards in either attended or unattended visual fields. Blood oxygenation level dependent (BOLD) responses to the different classes of stimuli were measured using functional magnetic resonance imaging. The older group had slower reaction times to targets, and committed more false alarms but had comparable detection accuracy to young controls. Attended target and novel stimuli activated comparable widely distributed attention networks, including anterior and posterior association cortex, in both groups. The older group had reduced spatial extent of activation in several regions, including prefrontal, basal ganglia, and visual processing areas. In particular, the anterior cingulate and superior frontal gyrus showed more restricted activation in older compared with young adults across all attentional conditions and stimulus categories. The spatial extent of activations correlated with task performance in both age groups, but the regional pattern of association between hemodynamic responses and behavior differed between the groups. Whereas the young subjects relied on posterior regions, the older subjects engaged frontal areas. The results indicate that aging alters the functioning of neural networks subserving visual attention, and that these changes are related to cognitive performance.
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Affiliation(s)
- Anne-Kristin Solbakk
- Department of Psychology and the Helen Wills Neuroscience Institute, University of California, Berkeley, CA, USA.
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33
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Chetty S. A Policy Framework for Epidemiological Studies in Air Pollution: The Multi-Point Plan in South Africa. Epidemiology 2007. [DOI: 10.1097/01.ede.0000288372.50539.c8] [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: 11/25/2022]
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34
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Rabinovici GD, Furst AJ, O'Neil JP, Racine CA, Mormino EC, Baker SL, Chetty S, Patel P, Pagliaro TA, Klunk WE, Mathis CA, Rosen HJ, Miller BL, Jagust WJ. 11C-PIB PET imaging in Alzheimer disease and frontotemporal lobar degeneration. Neurology 2007; 68:1205-12. [PMID: 17420404 DOI: 10.1212/01.wnl.0000259035.98480.ed] [Citation(s) in RCA: 246] [Impact Index Per Article: 14.5] [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] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND The PET tracer (11)C-labeled Pittsburgh Compound-B ((11)C-PIB) specifically binds fibrillar amyloid-beta (Abeta) plaques and can be detected in Alzheimer disease (AD). We hypothesized that PET imaging with (11)C-PIB would discriminate AD from frontotemporal lobar degeneration (FTLD), a non-Abeta dementia. METHODS Patients meeting research criteria for AD (n = 7) or FTLD (n = 12) and cognitively normal controls (n = 8) underwent PET imaging with (11)C-PIB (patients and controls) and (18)F-fluorodeoxyglucose ((18)F-FDG) (patients only). (11)C-PIB whole brain and region of interest (ROI) distribution volume ratios (DVR) were calculated using Logan graphical analysis with cerebellum as a reference region. DVR images were visually rated by a blinded investigator as positive or negative for cortical (11)C-PIB, and summed (18)F-FDG images were rated as consistent with AD or FTLD. RESULTS All patients with AD (7/7) had positive (11)C-PIB scans by visual inspection, while 8/12 patients with FTLD and 7/8 controls had negative scans. Of the four PIB-positive patients with FTLD, two had (18)F-FDG scans that suggested AD, and two had (18)F-FDG scans suggestive of FTLD. Mean DVRs were higher in AD than in FTLD in whole brain, lateral frontal, precuneus, and lateral temporal cortex (p < 0.05), while DVRs in FTLD did not significantly differ from controls. CONCLUSIONS PET imaging with (11)C-labeled Pittsburgh Compound-B ((11)C-PIB) helps discriminate Alzheimer disease (AD) from frontotemporal lobar degeneration (FTLD). Pathologic correlation is needed to determine whether patients with PIB-positive FTLD represent false positives, comorbid FTLD/AD pathology, or AD pathology mimicking an FTLD clinical syndrome.
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Affiliation(s)
- G D Rabinovici
- Memory &Aging Center, University of California San Fransisco, San Francisco, CA 94117, USA.
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Mackraj I, Somova L, Chetty S, Carstens ME. Regulation of renal alpha 2-adrenoceptor activity in Dahl salt-sensitive rats by dietary sodium changes. Methods Find Exp Clin Pharmacol 1998; 20:755-60. [PMID: 10022029] [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: 02/10/2023]
Abstract
The objective of the study was to evaluate the concept that genetically predisposed salt-sensitivity contributes to an increased adrenergic susceptibility and renal alpha 2-adrenoceptor (A2) abnormality in Dahl salt-sensitive hypertensive rats. The results showed: i) After 2 months of Na-loading (8% NaCl) Dahl salt-sensitive (DSS) rats expressed increased sodium and water retention which paralleled gradual development of diastolic hypertension. Low Na diet (0.5% NaCl) does not prevent hypertension but delays its development. ii) The increased activity of the sympathetic nervous system (SNS), in DSS rats corresponded to the development of hypertension and was stimulated by Na-loading. It was assessed by plasma catecholamine levels and heart rate changes. iii) The increased density of renal A2 by 29% was upregulated by high sodium diet, and coupled with increased norepinephrine level by 53%, only in DSS but not in DSR rats. iv) No strain renal A2 and epinephrine differences between DSS and DSR were found in weanling, prehypertensive rats, or in the adult DSS and DSR on low Na diet. By mediating an enhanced receptor-coupled response, such as increased proximal tubular sodium reabsorption during sodium loading, a genetic abnormality of renal alpha 2-adrenoceptors may contribute to some of the pathophysiologic derangements leading to hypertension in Dahl salt-sensitive rats.
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Affiliation(s)
- I Mackraj
- Department of Human Physiology and Physiological Chemistry, University of Durban-Westville, South Africa
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Somova L, Mackraj L, Chetty S. Sympathetic and platelet adrenergic activity and salt sensitivity: an experimental study. Methods Find Exp Clin Pharmacol 1998; 20:657-65. [PMID: 9922981 DOI: 10.1358/mf.1998.20.8.487492] [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] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The objective of the study was to evaluate the advanced hypothesis that genetically predisposed salt-sensitivity contributes to an increased adrenergic susceptibility and platelet activity and both these factors play a role in the pathogenesis of hypertension in a Dahl rat model. The results showed: i) Dahl salt-sensitive rats (DS) gradually develop a diastolic hypertension by the end of 3 months of age, in spite of the diet they are fed. Low-Na diet (0.5% NaCl) does not prevent hypertension but delays its development. High-Na diet (8%) exacerbates their hypertension. ii) After 2 months of Na-loading, DS rats expressed significantly increased sodium and water retention and increased plasma volume by 15%, compared with 2.8% in Dahl salt-resistant (DR) rats on high-Na diet. iii) The increased activity of the sympathetic nervous system (SNS) in DS rats paralleled the development of hypertension and was stimulated by Na-loading. It was assessed by their catecholamines status and heart rate changes. iv) Platelet activity of DS rats was increased as reflected in collagen-induced nonstimulated and adrenaline-stimulated aggregation, and an increased plasma T x B2/6-keto PGF1 alpha ratio. Na-loading further increased platelet activity. v) Both DR and DS rat platelets displayed alpha 2-adrenoceptors (A2) of low binding capacity (Bmax 25 and 35 fmol/mg protein, respectively) and low affinity (KD 5.6 nM for both groups), suggesting that platelet alpha 2 adrenoceptors in this strain of rats might not play a significant biological role in their increased platelet activity. The fact that platelet alpha 2-adrenoceptors do not define the stimulation of SNS in DS rat do not exclude their participation in development of salt-dependent hypertension, since a genetic defect(s) of these ubiquitous receptors (brain, kidney, blood vessels) could still contribute to the pathogenesis of the disease.
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Affiliation(s)
- L Somova
- Department of Human Physiology and Physiological Chemistry, University of Durban-Westville, South Africa
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Abstract
AIMS To assess the immunoexpression of cyclin D1 and retinoblastoma in a cohort of oesophageal squamous cell carcinoma cases from South Africa to see whether there is a relation between these two proteins. In addition, protein expression was correlated with clinicopathological features. METHODS Fifty biopsies and 30 oesophagectomy specimens were immunostained with commercially available antibodies to cyclin D1 and retinoblastoma proteins, following microwave antigen retrieval. RESULTS Twenty three of the 80 cases (29%) showed cyclin D1 protein expression. However, only five cases had > 50% of the tumour cells displaying immunopositivity. Three of the four cases with lymph node spread were cyclin D1 positive in the primary tumour and the metastasis. Fifty three cases were immunoreactive with the antiretinoblastoma antibody; 29 of these cases showing > 50% of cells with immunolabelling. Of the 23 cyclin D1 positive cases, 18 were also retinoblastoma positive. No correlation was observed between cyclin D1 and retinoblastoma protein expression and age, sex, race, or histological grade. CONCLUSIONS Cyclin D1 is expressed in a minority of cases of oesophageal squamous carcinomas from South Africa. However, three of four cases with lymph node spread were cyclin D1 positive, thus indicating that cyclin D1 positive tumours may have a greater propensity for spread. In addition, 18 of 23 cyclin D1 positive cases also expressed retinoblastoma protein. These findings suggest a possible relation between cyclin D1 and retinoblastoma proteins in a proportion of cases of oesophageal squamous.
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Affiliation(s)
- R Chetty
- Department of Anatomical Pathology, University of Natal School of Medicine, Congella, Durban, South Africa
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Abstract
Results of percutaneous mitral valvotomy were compared in two groups undergoing the procedure at our institution. Group I: 100 patients having had percutaneous valvotomy with the Schneider-Medintag bifoil (2 x 19 mm) or trefoil (3 x 15 mm or 3 x 12 mm) catheters, and group II; 150 patients in whom the procedure was performed with the Inoue balloon (24-30 mm). Baseline clinical (age, gender, NYHA class and echo score) and haemodynamic variables were similar in both groups. Haemodynamic improvement occurred in both groups. Although the reduction in left atrial pressure did not differ significantly between the two groups, the increase in mitral valve area was significantly (P < 0.001) higher for group I (0.8 +/- 0.2 to 1.9 +/- 0.7 and 0.8 +/- 0.3 to 1.6 +/- 0.3 cm2 respectively for mitral area, and 22 +/- 6 to 13 +/- 5 and 21 +/- 6 to 13 +/- 5 mmHg respectively for mean left atrial pressure). The increase in cardiac output was statistically significant in group I (3.2 +/- 0.7 to 4.0 +/- 0.9 l.min-1, P < 0.05) but not in group II (3.5 +/- 2.0 to 3.7 +/- 0.9 l.min-1, ns). Inter-atrial shunting immediately after valvotomy was recorded in 19% of group I patients compared with 6% in group II (P < 0.001). The overall incidence of significant mitral regurgitation (3+ or 4+) was similar in both groups (5% and 4% respectively). However, when the stepwise dilatation technique was employed in group II, the incidence had dropped to 2.1%.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- J J Patel
- Cardiology Department, University of Natal/Wentworth Hospital, Durban, South Africa
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Abstract
Percutaneous balloon mitral valvotomy was attempted in severely symptomatic (New York Heart Association class III or IV) pregnant patients (mean age 30 years) with tight mitral stenosis. Nineteen patients were pregnant (mean gestation 30 weeks, range 26 to 34) and one patient was in the immediate postpartum period. All patients had undergone a trial of diuretic therapy and 16 were also taking atenolol. Percutaneous valvotomy was performed with the Inoue catheter (18 patients) or the Schneider-Medintag bifoil (2 x 19 mm) balloon catheter (2 patients). The fluoroscopy time was 9.2 +/- 3.4 minutes. After percutaneous valvotomy the mean mitral gradient decreased from 17.9 +/- 6.2 to 5.9 +/- 2.4 mm Hg (p < 0.001). The mitral valve area (pressure half time) increased from 0.8 +/- 0.2 to 1.7 +/- 0.2 cm2 (p < 0.001). These hemodynamic changes were accompanied by immediate symptomatic improvement by at least one New York Heart Association functional grade in all patients. Moderate (3+) mitral regurgitation developed in one patient. Eighteen patients had normal infants delivered vaginally at term without assistance, and one patient had a normal infant delivered by cesarean section at 35 weeks' gestation. We conclude that percutaneous balloon mitral valvotomy for pliable mitral stenosis in pregnancy is safe for both the mother and fetus. We recommend that it be performed in symptomatic patients with tight mitral stenosis so as to avoid hemodynamic complications in the latter stages of pregnancy.
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Affiliation(s)
- J J Patel
- Cardiac Unit, Wentworth Hospital, Jacobs, South Africa
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Abstract
Even though one of the characteristic features of myotonic dystrophy (MyD) is the high level of circulating insulin, 125I-insulin-binding data in MyD have been controversial. In the present study we utilized cultured monocytes to avoid problems of reproducibility and variability in age, and examined the affinity and binding characteristics of 125I-insulin binding in MyD patients and controls. The Bmax and mean affinity constant, Ka, were significantly lower, while the number of receptors per cell had increased in the patient group as compared to the controls. The data confirm our earlier findings that there is no primary defect in insulin receptors in MyD, and the disturbed insulin response may be due to an abnormality in the membrane environment. Since the insulin receptor is an integral membrane protein, abnormal plasma membrane lipid composition may lead to impaired lipid-protein interactions, and hence affect the binding characteristics in MyD.
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Patel JJ, Shama D, Mitha AS, Blyth D, Hassen F, Le Roux BT, Chetty S. Balloon valvuloplasty versus closed commissurotomy for pliable mitral stenosis: a prospective hemodynamic study. J Am Coll Cardiol 1991; 18:1318-22. [PMID: 1918709 DOI: 10.1016/0735-1097(91)90555-n] [Citation(s) in RCA: 114] [Impact Index Per Article: 3.5] [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: 12/29/2022]
Abstract
Closed surgical mitral valvotomy is the procedure of choice in most patients with symptomatic pliable mitral stenosis in developing countries. The procedure is efficacious and safe. Mitral valvotomy performed with a balloon has shown similar good results, with infrequent complications in selected subjects. Because there is a paucity of studies comparing the two techniques, this study was undertaken to compare the results of percutaneous balloon mitral valvuloplasty with those of closed commissurotomy as determined by catheterization studies. Forty-five patients with tight pliable mitral stenosis were randomly assigned to one of two groups: 23 patients had balloon valvuloplasty by the single catheter technique (group I) and 22 underwent closed surgical valvotomy (group II). The two groups were similar with regard to clinical and hemodynamic findings before intervention. Mitral valve area increased from 0.8 +/- 0.3 to 2.1 +/- 0.7 cm2 in group I (p less than 0.001) and from 0.7 +/- 0.2 to 1.3 +/- 0.3 cm2 in group II (p less than 0.001). Pulmonary artery pressure and pulmonary vascular resistance decreased in both groups, but these changes did not reach statistical significance in group II. Treadmill exercise time increased from 3.8 +/- 2.3 to 7.3 +/- 2.6 min in group I (p less than 0.001) and from 4 +/- 2.6 to 5.6 +/- 2.6 min in group II (p less than 0.001). There were no deaths. One patient in each group developed moderate (3+) mitral regurgitation. A small interatrial shunt (less than 1.5:1) was detected in three patients in group I immediately after the procedure.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- J J Patel
- Division of Cardiology, University of Natal, Durban, South Africa
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Naidoo DP, Mitha AS, Vythilingum S, Chetty S. Pulmonary hypertension in aortic regurgitation: early surgical outcome. Q J Med 1991; 80:589-95. [PMID: 1946939] [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: 12/29/2022]
Abstract
A review of the haemodynamic data of 139 patients with isolated, severe, chronic aortic regurgitation revealed severe pulmonary hypertension (pulmonary artery systolic pressure of greater than or equal to 60 mmHg) in 34 (24 per cent). The left ventricular end-diastolic pressure was high in all patients, suggesting that pulmonary hypertension was a consequence of severe long-standing regurgitation with ventricular dysfunction. Aortic valve replacement was performed in 69 patients, 33 of whom had normal or mildly elevated pulmonary artery systolic pressure (less than 39 mmHg; group I) and 36 of whom had moderate or markedly elevated pulmonary artery systolic pressures (less than 40 mmHg; group II). There was no difference in mortality or prevalence of post-operative complications between these two groups of patients. Furthermore, New York Heart Association (NYHA) functional class and cardiothoracic ratio were similar in both groups at the six-month assessment. The pulmonary vascular resistance fell from 4.7 +/- 3.5 to 1.5 +/- 0.8 units x m2 in 13 of 17 patients who had repeat catheterization after surgery. Pulmonary artery systolic pressure reverted to normal in 10 of these 13 patients. It is concluded that pulmonary hypertension consequent upon raised left ventricular end-diastolic pressure is common in severe aortic regurgitation, is largely reversible, and does not influence the early outcome after aortic valve replacement.
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Affiliation(s)
- D P Naidoo
- Department of Medicine, Faculty of Medicine, University of Natal, Durban, Republic of South Africa
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Chetty S, Mitha AS. Arrhythmias in idiopathic dilated cardiomyopathy. A preliminary study. S Afr Med J 1990; 77:190-3. [PMID: 2300853] [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: 12/31/2022] Open
Abstract
Idiopathic dilated cardiomyopathy is second to valvular heart disease as a cause of congestive heart failure in blacks in southern Africa. The disease has a deteriorating clinical course with high mortality. More than half these deaths are sudden and have been related to arrhythmias. In a preliminary study of 20 black patients in congestive heart failure caused by dilated cardiomyopathy, 24-hour ambulatory ECG monitoring was used to assess the prevalence, type and clinical significance of arrhythmias. Eighteen of the 20 patients (90%) had arrhythmias. Supraventricular arrhythmias were detected in 17 (85% of the total), and 18 (90%) had complex ventricular arrhythmias. Eleven (55%) had non-sustained ventricular tachycardia (VT). There was no correlation between complex ventricular arrhythmia and clinical features, resting ECG, chest radiograph or echocardiographic data. Over a 3-year period 13 patients died (65%), half these deaths being unexpected. All 13 had complex ventricular arrhythmias, and those who died suddenly had non-sustained VT. This small prospective study shows that ventricular arrhythmias are common in dilated cardiomyopathy in blacks and are frequently complex and dangerous. Sudden death is common and is more than likely to be related to VT in the presence of an already poorly functioning left ventricle.
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Affiliation(s)
- S Chetty
- Cardiac Unit, Wentworth Hospital, Durban
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Chetty S, Mitha AS. High-dose oral amoxycillin in the treatment of infective endocarditis. S Afr Med J 1988; 73:709-10. [PMID: 3381154] [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: 01/05/2023] Open
Abstract
Oral antibiotic therapy for infective endocarditis is not yet widely accepted. A study was undertaken to assess the efficacy of oral amoxycillin in this condition. Fifteen patients were treated with high-dose oral amoxycillin for 6 weeks. Twelve responded to treatment and remain well at 3 years. There were 3 deaths--1 at day 7 due to sudden aortic cusp rupture, and 2 late deaths due to pulmonary and cerebral embolism respectively. There was 1 relapse of streptococcal prosthetic valve endocarditis 8 weeks after oral treatment, but this responded to conventional intravenous therapy. Oral amoxycillin is effective in uncomplicated streptococcal endocarditis, and should not be used with prosthetic valve infections.
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Affiliation(s)
- S Chetty
- Cardiac Unit, Wentworth Hospital
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Doi YL, McKenna WJ, Chetty S, Oakley CM, Goodwin JF. Prediction of mortality and serious ventricular arrhythmia in hypertrophic cardiomyopathy. An echocardiographic study. Heart 1980; 44:150-7. [PMID: 7191710 PMCID: PMC482374 DOI: 10.1136/hrt.44.2.150] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
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McKenna WJ, Chetty S, Oakley CM, Goodwin JF. Arrhythmia in hypertrophic cardiomyopathy: exercise and 48 hour ambulatory electrocardiographic assessment with and without beta adrenergic blocking therapy. Am J Cardiol 1980; 45:1-5. [PMID: 6101296 DOI: 10.1016/0002-9149(80)90212-x] [Citation(s) in RCA: 125] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Submaximal treadmill exercise electrocardiography and 48 hour ambulatory electrocardiographic monitoring were performed in 30 patients with hypertrophic cardiomyopathy both with and without beta adrenergic blocking therapy. During ambulatory electrocardiographic monitoring 1 patient (3 percent) had no arrhythmia, 14 patients (46 percent) had supraventricular tachycardia or paroxysmal atrial fibrillation, 13 (43 percent) had multiform or paired ventricular extrasystoles and 8 (26 percent) had ventricular tachycardia. The frequency of these ventricular arrhythmias was almost identical with and without beta adrenergic blocking drugs (mean dose in "propranolol equivalents" 280 mg daily). With beta blocking therapy fewer patients had supraventricular tachycardia; however, the difference was not significant. During exercise testing 18 patients (60 percent) had ventricular extrasystoles and 3 patients (10 percent) had paired ventricular extrasystoles and the frequency was almost identical with and without beta adrenergic blocking therapy. No routine echocardiographic or hemodynamic measurement predicted the serious ventricular arrhythmias. It is concluded that asymptomatic ventricular arrhythmia is a common occurrence in patients with hypertrophic cardiomyopathy and its frequency is not reduced with beta adrenergic blocking therapy. Because occult arrhythmia may be the cause of sudden death it is important to detect it in these patients so that an effort can be made to improve prognosis with specific antiarrhythmic treatment.
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Seedat YK, Grant W, Chetty S. Bilateral renal cortical necrosis: a report of 2 cases. S Afr Med J 1976; 50:933-6. [PMID: 1084581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Two cases of renal cortical necrosis, one of which occurred after an obstetric complication (abruptio placentae) and the other after postpartum haemorrhage, are described. The diagnosis was made by percutaneous renal biopsy, intravenous pyelography and selective nephro-angiography. Immunofluorescence studies of the kidney showed no abnormality in one patient, but showed the presence of IgM in the glomerular basement membrane in the second patient. Hypotension was not observed when anuria occurred. Both patients survived. The importance of prolonged haemodialysis is stressed, since one patient was oliguric for 57 days and required intermittent haemodialysis for 5 months, while the second patient was oliguric for 17 days, required haemodialysis for 5 months and now has established hypertension.
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Holloway R, Chetty S, Moodley P. Net and gross lung failure among patients sent for pulmonary function testing. S Afr Med J 1972; 46:404-8. [PMID: 5025249] [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: 01/13/2023] Open
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