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Caparrós-Martín JA, Maher P, Ward NC, Saladié M, Agudelo-Romero P, Stick SM, Chan DC, Watts GF, O’Gara F. An Analysis of the Gut Microbiota and Related Metabolites following PCSK9 Inhibition in Statin-Treated Patients with Elevated Levels of Lipoprotein(a). Microorganisms 2024; 12:170. [PMID: 38257996 PMCID: PMC10818477 DOI: 10.3390/microorganisms12010170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Revised: 12/26/2023] [Accepted: 01/08/2024] [Indexed: 01/24/2024] Open
Abstract
BACKGROUND Atherosclerotic cardiovascular disease (ASCVD) is a leading cause of global mortality, often associated with high blood levels of LDL cholesterol (LDL-c). Medications like statins and PCSK9 inhibitors, are used to manage LDL-c levels and reduce ASCVD risk. Recent findings connect the gut microbiota and its metabolites to ASCVD development. We showed that statins modulate the gut microbiota including the production of microbial metabolites involved in the regulation of cholesterol metabolism such as short chain fatty acids (SCFAs) and bile acids (BAs). Whether this pleiotropic effect of statins is associated with their antimicrobial properties or it is secondary to the modulation of cholesterol metabolism in the host is unknown. In this observational study, we evaluated whether alirocumab, a PCSK9 inhibitor administered subcutaneously, alters the stool-associated microbiota and the profiles of SCFAs and BAs. METHODS We used stool and plasma collected from patients enrolled in a single-sequence study using alirocumab. Microbial DNA was extracted from stool, and the bacterial component of the gut microbiota profiled following an amplicon sequencing strategy targeting the V3-V4 region of the 16S rRNA gene. Bile acids and SCFAs were profiled and quantified in stool and plasma using mass spectrometry. RESULTS Treatment with alirocumab did not alter bacterial alpha (Shannon index, p = 0.74) or beta diversity (PERMANOVA, p = 0.89) in feces. Similarly, circulating levels of SCFAs (mean difference (95% confidence interval (CI)), 8.12 [-7.15-23.36] µM, p = 0.25) and BAs (mean difference (95% CI), 0.04 [-0.11-0.19] log10(nmol mg-1 feces), p = 0.56) were equivalent regardless of PCSK9 inhibition. Alirocumab therapy was associated with increased concentration of BAs in feces (mean difference (95% CI), 0.20 [0.05-0.34] log10(nmol mg-1 feces), p = 0.01). CONCLUSION In statin-treated patients, the use of alirocumab to inhibit PCSK9 leads to elevated levels of fecal BAs without altering the bacterial population of the gut microbiota. The association of alirocumab with increased fecal BA concentration suggests an additional mechanism for the cholesterol-lowering effect of PCSK9 inhibition.
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Affiliation(s)
- Jose A. Caparrós-Martín
- Wal-yan Respiratory Research Centre, Telethon Kids Institute, Perth, WA 6009, Australia
- Curtin Health Innovation Research Institute (CHIRI), Curtin University, Perth, WA 6102, Australia
| | - Patrice Maher
- Curtin Health Innovation Research Institute (CHIRI), Curtin University, Perth, WA 6102, Australia
| | - Natalie C. Ward
- Dobney Hypertension Centre, Medical School, The University of Western Australia, Perth, WA 6009, Australia
| | - Montserrat Saladié
- Curtin Health Innovation Research Institute (CHIRI), Curtin University, Perth, WA 6102, Australia
| | - Patricia Agudelo-Romero
- Wal-yan Respiratory Research Centre, Telethon Kids Institute, Perth, WA 6009, Australia
- The University of Western Australia, Perth, WA 6009, Australia
| | - Stephen M. Stick
- Wal-yan Respiratory Research Centre, Telethon Kids Institute, Perth, WA 6009, Australia
- The University of Western Australia, Perth, WA 6009, Australia
- Department of Respiratory Medicine, Princess Margaret Hospital for Children, Perth, WA 6008, Australia
| | - Dick C. Chan
- Medical School, Faculty of Health and Medical Sciences, The University of Western Australia, Perth, WA 6009, Australia
| | - Gerald F. Watts
- Medical School, Faculty of Health and Medical Sciences, The University of Western Australia, Perth, WA 6009, Australia
- Cardiometabolic Service, Departments of Cardiology and Internal Medicine, Royal Perth Hospital, Perth, WA 6000, Australia
| | - Fergal O’Gara
- Wal-yan Respiratory Research Centre, Telethon Kids Institute, Perth, WA 6009, Australia
- Curtin Health Innovation Research Institute (CHIRI), Curtin University, Perth, WA 6102, Australia
- BIOMERIT Research Centre, School of Microbiology, University College Cork, T12 XF62 Cork, Ireland
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Wong SY, Foley S, Cantwell CP, Ryan R, Lucey J, Maher P, McNulty JP. THE EFFECTS OF CONE-BEAM COMPUTED TOMOGRAPHY IMAGING GUIDANCE ON PATIENT RADIATION EXPOSURES IN TRANS-ARTERIAL CHEMOEMBOLISATION FOR HEPATOCELLULAR CARCINOMA. Radiat Prot Dosimetry 2022; 198:441-447. [PMID: 35640248 PMCID: PMC9248773 DOI: 10.1093/rpd/ncac077] [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] [Figures] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 03/21/2022] [Accepted: 04/26/2022] [Indexed: 06/15/2023]
Abstract
This study investigated the effects of cone-beam computed tomography (CBCT) guidance in trans-arterial chemoembolisation (TACE) procedures on the number of digital subtraction angiography (DSA) runs acquired and total patient radiation exposure in patients with hepatocellular carcinoma (HCC). A retrospective, analytical cross-sectional, single institution, study was conducted. Dose data were compared across the control (DSA guidance alone) and study (DSA and CBCT guidance) groups. A total of 122 procedures were included within the study. There was a significant reduction in the number of DSA runs (3 vs 5, p < 0.001) and DSA air kerma-area product (PKA) (3077.3 vs 4276.6 μGym2, p = 0.042) for the study group when compared to the control group. Total procedural PKA and total procedural reference air kerma (Ka,r) were shown to be 50 and 73% higher, respectively, for the study group when compared to the control group. CBCT imaging guidance does reduce the number of DSA runs and DSA PKA required to complete the TACE procedure for patients diagnosed with HCC; however, a substantial increase in total procedural PKA is to be expected and it is thus important that this increased dose is carefully considered and justified.
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Affiliation(s)
- S Y Wong
- Radiography and Diagnostic Imaging, School of Medicine, University College Dublin, Dublin 4, Ireland
- Department of Radiology, St. Vincent’s University Hospital, Elm Park, Dublin 4, Ireland
- Department of Diagnostic Radiology, Singapore General Hospital, Outram Road, Singapore 169608, Singapore
| | - S Foley
- Radiography and Diagnostic Imaging, School of Medicine, University College Dublin, Dublin 4, Ireland
- Department of Radiology, St. Vincent’s University Hospital, Elm Park, Dublin 4, Ireland
| | - C P Cantwell
- Department of Radiology, St. Vincent’s University Hospital, Elm Park, Dublin 4, Ireland
- School of Medicine, University College Dublin, Dublin 4, Ireland
| | - R Ryan
- Department of Radiology, St. Vincent’s University Hospital, Elm Park, Dublin 4, Ireland
- School of Medicine, University College Dublin, Dublin 4, Ireland
| | - J Lucey
- Department of Radiology, St. Vincent’s University Hospital, Elm Park, Dublin 4, Ireland
- School of Medicine, University College Dublin, Dublin 4, Ireland
| | - P Maher
- Department of Radiology, St. Vincent’s University Hospital, Elm Park, Dublin 4, Ireland
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McCaughey C, Healy GM, Al Balushi H, Maher P, McCavana J, Lucey J, Cantwell CP. Patient radiation dose during angiography and embolization for abdominal hemorrhage: the influence of CT angiography, fluoroscopy system, patient and procedural variables. CVIR Endovasc 2022; 5:12. [PMID: 35171363 PMCID: PMC8850522 DOI: 10.1186/s42155-022-00284-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2021] [Accepted: 01/06/2022] [Indexed: 11/19/2022] Open
Abstract
Background Angiography and embolization (AE) is a lifesaving, high radiation dose procedure for treatment of abdominal arterial hemorrhage (AAH). Interventional radiologists have utilized pre-procedure CT angiography (CTA) and newer fluoroscopic systems in an attempt to reduce radiation dose and procedure time. Purpose To study the factors contributing to the radiation dose of AE for AAH and to compare to the reference standard. Materials and methods This retrospective single-centre observational cohort study identified 154 consecutive AE procedures in 138 patients (median age 65 years; interquartile range 54–77; 103 men) performed with a C-arm fluoroscopic system (Axiom Artis DTA or Axiom Artis Q (Siemens Healthineers)), between January 2010 and December 2017. Parameters analysed included: demographics, fluoroscopy system, bleeding location, body mass index (BMI), preprocedural CT, air kerma-area product (PKA), reference air kerma (Ka,r), fluoroscopy time (FT) and the number of digital subtraction angiography (DSA) runs. Factors affecting dose were assessed using Mann–Whitney U, Kruskal–Wallis one-way ANOVA and linear regression. Results Patients treated with the new angiographic system (NS) had a median PKA, median Ka,r, Q3 PKA and Q3 Ka,r that were 74% (p < 0.0005), 66%(p < 0.0005), 55% and 52% lower respectively than those treated with the old system (OS). This dose reduction was consistent for each bleeding location (upper GI, Lower GI and extraluminal). There was no difference in PKA (p = 0.452), Ka,r (p = 0.974) or FT (p = 0.179), between those who did (n = 137) or did not (n = 17) undergo pre-procedure CTA. Other factors significantly influencing radiation dose were: patient BMI and number of DSA runs. A multivariate model containing these variables accounts for 15.2% of the variance in Ka,r (p < 0.005) and 45.9% of the variance of PKA (p < 0.005). Conclusion Radiation dose for AE in AAH is significantly reduced by new fluoroscopic technology. Higher patient body mass index is an independent key parameter affecting patient dose. Radiation dose was not influenced by haemorrhage site or performance of pre-procedure CTA.
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Affiliation(s)
| | - Gerard M Healy
- Department of Radiology, St Vincent's University Hospital, Dublin, Ireland
| | | | - Patrice Maher
- Department of Radiology, St Vincent's University Hospital, Dublin, Ireland
| | - Jackie McCavana
- Department of Medical Physics and Clinical Engineering, St Vincent's University Hospital, Dublin, Ireland
| | - Julie Lucey
- Department of Medical Physics and Clinical Engineering, St Vincent's University Hospital, Dublin, Ireland
| | - Colin P Cantwell
- Department of Radiology, St Vincent's University Hospital, Dublin, Ireland.,School of Medicine, University College Dublin, Dublin, Ireland
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Staunton S, Rajendran D, Maher P, McCann J, McNicholas S, Feeney E, O’Broin C, Savinelli S, Mallon P, Watson A, Waqas S. Discharge-delaying factors for patients suitable for outpatient parenteral antimicrobial therapy (OPAT) in an Irish tertiary hospital during COVID-19. JAC Antimicrob Resist 2021; 3:dlab163. [PMID: 34661108 PMCID: PMC8516592 DOI: 10.1093/jacamr/dlab163] [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] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Affiliation(s)
- S Staunton
- Department of Medicine, St Vincent’s University Hospital, Elm Park, Dublin 4, Ireland
| | - D Rajendran
- Department of Infectious Diseases, St Vincent’s University Hospital, Elm Park, Dublin 4, Ireland
| | - P Maher
- Department of Radiology, St Vincent’s University Hospital, Elm Park, Dublin 4, Ireland
| | - J McCann
- Department of Radiology, St Vincent’s University Hospital, Elm Park, Dublin 4, Ireland
| | - S McNicholas
- Department of Microbiology, St Vincent’s University Hospital, Elm Park, Dublin 4, Ireland
| | - E Feeney
- Department of Infectious Diseases, St Vincent’s University Hospital, Elm Park, Dublin 4, Ireland
| | - C O’Broin
- Department of Infectious Diseases, St Vincent’s University Hospital, Elm Park, Dublin 4, Ireland
| | - S Savinelli
- Department of Infectious Diseases, St Vincent’s University Hospital, Elm Park, Dublin 4, Ireland
| | - P Mallon
- Department of Infectious Diseases, St Vincent’s University Hospital, Elm Park, Dublin 4, Ireland
| | - A Watson
- Department of Medicine, St Vincent’s University Hospital, Elm Park, Dublin 4, Ireland
| | - S Waqas
- Department of Infectious Diseases, St Vincent’s University Hospital, Elm Park, Dublin 4, Ireland
- UCD School of Medicine, University College Dublin, Belfield, Dublin 4, Ireland
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Ma TJ, Ellett L, McIlwaine K, Manwaring J, Readman E, Maher P. Can Narrowband Imaging Improve the Laparoscopic Identification of Superficial Endometriosis? A Prospective Cohort Trial. J Minim Invasive Gynecol 2016. [DOI: 10.1016/j.jmig.2016.08.007] [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: 10/20/2022]
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Maher P, Ma T, Ellett L, Stone K, Yang N, Esler S, Brouwer R, McIlwaine K, Manwaring J, Readman E. Ability of MRI and Ultrasound with Multidisciplinary Meeting to Pre Operatively Predict the Need for Bowel Resection. J Minim Invasive Gynecol 2016; 22:S28. [PMID: 27679195 DOI: 10.1016/j.jmig.2015.08.078] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Affiliation(s)
- P Maher
- Endosurgery Department, Mercy Hospital for Women, Melbourne, Victoria, Australia
| | - T Ma
- Endosurgery Department, Mercy Hospital for Women, Melbourne, Victoria, Australia
| | - L Ellett
- Endosurgery Department, Mercy Hospital for Women, Melbourne, Victoria, Australia
| | - K Stone
- Ultrasound Department, Mercy Hospital for Women, Melbourne, Victoria, Australia
| | - N Yang
- Department of Radiology, Austin Hospital, Melbourne, Victoria, Australia
| | - S Esler
- Department of Radiology, Austin Hospital, Melbourne, Victoria, Australia
| | - R Brouwer
- Colorectal Surgery Department, Austin Hospital, Melbourne, Victoria, Australia
| | - K McIlwaine
- Endosurgery Department, Mercy Hospital for Women, Melbourne, Victoria, Australia
| | - J Manwaring
- Endosurgery Department, Mercy Hospital for Women, Melbourne, Victoria, Australia
| | - E Readman
- Endosurgery Department, Mercy Hospital for Women, Melbourne, Victoria, Australia
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7
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Dafre AL, Goldberg J, Wang T, Spiegel DA, Maher P. Methylglyoxal, the foe and friend of glyoxalase and Trx/TrxR systems in HT22 nerve cells. Free Radic Biol Med 2015; 89:8-19. [PMID: 26165190 PMCID: PMC5624793 DOI: 10.1016/j.freeradbiomed.2015.07.005] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Revised: 06/03/2015] [Accepted: 07/06/2015] [Indexed: 01/28/2023]
Abstract
Methylglyoxal (MGO) is a major glycating agent that reacts with basic residues of proteins and promotes the formation of advanced glycation end products (AGEs) which are believed to play key roles in a number of pathologies, such as diabetes, Alzheimer's disease, and inflammation. Here, we examined the effects of MGO on immortalized mouse hippocampal HT22 nerve cells. The endpoints analyzed were MGO and thiol status, the glyoxalase system, comprising glyoxalase 1 and 2 (GLO1/2), and the cytosolic and mitochondrial Trx/TrxR systems, as well as nuclear Nrf2 and its target genes. We found that nuclear Nrf2 is induced by MGO treatment in HT22 cells, as corroborated by induction of the Nrf2-controlled target genes and proteins glutamate cysteine ligase and heme oxygenase 1. Nrf2 knockdown prevented MGO-dependent induction of glutamate cysteine ligase and heme oxygenase 1. The cystine/glutamate antiporter, system xc(-), which is also controlled by Nrf2, was also induced. The increased cystine import (system xc(-)) activity and GCL expression promoted GSH synthesis, leading to increased levels of GSH. The data indicate that MGO can act as both a foe and a friend of the glyoxalase and the Trx/TrxR systems. At low concentrations of MGO (0.3mM), GLO2 is strongly induced, but at high MGO (0.75 mM) concentrations, GLO1 is inhibited and GLO2 is downregulated. The cytosolic Trx/TrxR system is impaired by MGO, where Trx is downregulated yet TrxR is induced, but strong MGO-dependent glycation may explain the loss in TrxR activity. We propose that Nrf2 can be the unifying element to explain the observed upregulation of GSH, GCL, HO1, TrxR1, Trx2, TrxR2, and system xc(-) system activity.
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Affiliation(s)
- A L Dafre
- Biochemistry Department, Federal University of Santa Catarina, Florianópolis, SC, Brazil.
| | - J Goldberg
- Cellular Neurobiology Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - T Wang
- Department of Chemistry, Yale University, New Haven, CT 06520, USA
| | - D A Spiegel
- Department of Chemistry, Yale University, New Haven, CT 06520, USA
| | - P Maher
- Cellular Neurobiology Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
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8
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Abstract
Objectives Metal-on-metal hip resurfacing (MOMHR) is available as an alternative
option for younger, more active patients. There are failure modes
that are unique to MOMHR, which include loosening of the femoral
head and fractures of the femoral neck. Previous studies have speculated
that changes in the vascularity of the femoral head may contribute
to these failure modes. This study compares the survivorship between
the standard posterior approach (SPA) and modified posterior approach
(MPA) in MOMHR. Methods A retrospective clinical outcomes study was performed examining
351 hips (279 male, 72 female) replaced with Birmingham Hip Resurfacing
(BHR, Smith and Nephew, Memphis, Tennessee) in 313 patients with
a pre-operative diagnosis of osteoarthritis. The mean follow-up
period for the SPA group was 2.8 years (0.1 to 6.1) and for the
MPA, 2.2 years (0.03 to 5.2); this difference in follow-up period
was statistically significant (p < 0.01). Survival analysis was
completed using the Kaplan–Meier method. Results At four years, the Kaplan–Meier survival curve for the SPA was
97.2% and 99.4% for the MPA; this was statistically significant
(log-rank; p = 0.036). There were eight failures in the SPA and
two in the MPA. There was a 3.5% incidence of femoral head collapse
or loosening in the SPA and 0.4% in the MPA, which represented a
significant difference (p = 0.041). There was a 1.7% incidence of
fractures of the femoral neck in the SPA and none in the MPA (p
= 0.108). Conclusion This study found a significant difference in survivorship at
four years between the SPA and the MPA (p = 0.036). The clinical
outcomes of this study suggest that preserving the vascularity of
the femoral neck by using the MPA results in fewer vascular-related
failures in MOMHRs. Cite this article: Bone Joint Res 2014;3:150–4
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Affiliation(s)
- K M Takamura
- UCLA David Geffen School of Medicine, 10833 Le Conte Avenue, Los Angeles, California 90095, USA
| | - P Maher
- Weill Cornell Medical College, 1300 York Ave, New York, New York 10021, USA
| | - T Nath
- Center for Hip Preservation, 535 East 70th Street, New York, New York 10021, USA
| | - E P Su
- Hospital for Special Surgery, 535 East 70th street, New York, New York 10021, USA
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Dean CR, Wang L, Maher P, Forsythe C, Ghahari F, Gao Y, Katoch J, Ishigami M, Moon P, Koshino M, Taniguchi T, Watanabe K, Shepard KL, Hone J, Kim P. Hofstadter's butterfly and the fractal quantum Hall effect in moiré superlattices. Nature 2013; 497:598-602. [PMID: 23676673 DOI: 10.1038/nature12186] [Citation(s) in RCA: 561] [Impact Index Per Article: 51.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2012] [Accepted: 04/03/2013] [Indexed: 11/09/2022]
Abstract
Electrons moving through a spatially periodic lattice potential develop a quantized energy spectrum consisting of discrete Bloch bands. In two dimensions, electrons moving through a magnetic field also develop a quantized energy spectrum, consisting of highly degenerate Landau energy levels. When subject to both a magnetic field and a periodic electrostatic potential, two-dimensional systems of electrons exhibit a self-similar recursive energy spectrum. Known as Hofstadter's butterfly, this complex spectrum results from an interplay between the characteristic lengths associated with the two quantizing fields, and is one of the first quantum fractals discovered in physics. In the decades since its prediction, experimental attempts to study this effect have been limited by difficulties in reconciling the two length scales. Typical atomic lattices (with periodicities of less than one nanometre) require unfeasibly large magnetic fields to reach the commensurability condition, and in artificially engineered structures (with periodicities greater than about 100 nanometres) the corresponding fields are too small to overcome disorder completely. Here we demonstrate that moiré superlattices arising in bilayer graphene coupled to hexagonal boron nitride provide a periodic modulation with ideal length scales of the order of ten nanometres, enabling unprecedented experimental access to the fractal spectrum. We confirm that quantum Hall features associated with the fractal gaps are described by two integer topological quantum numbers, and report evidence of their recursive structure. Observation of a Hofstadter spectrum in bilayer graphene means that it is possible to investigate emergent behaviour within a fractal energy landscape in a system with tunable internal degrees of freedom.
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Affiliation(s)
- C R Dean
- Department of Physics, The City College of New York, New York, New York 10031, USA
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Herrera F, Maher P, Schubert D. c-Jun N-terminal kinase controls a negative loop in the regulation of glial fibrillary acidic protein expression by retinoic acid. Neuroscience 2012; 208:143-9. [PMID: 22387108 DOI: 10.1016/j.neuroscience.2012.02.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2011] [Revised: 01/31/2012] [Accepted: 02/08/2012] [Indexed: 11/26/2022]
Abstract
Glial fibrillary acidic protein (GFAP) is a protein widely used as a molecular marker for astroglial differentiation and mature astrocytes. We and others have shown previously that retinoic acid and specific cytokines induce the expression of GFAP in neural precursor cells by activating the phosphatidylinositol-4,5-bisphosphate-3-kinase (PI3K) phosphorylation pathway. Here, we extend our previous work and show that retinoic acid also activates specifically the c-Jun N-terminal kinase (JNK) phosphorylation pathway, which in turn inhibits GFAP expression. Our results suggest the existence of a negative self-regulatory loop in the phosphorylation pathways that regulates GFAP expression. This loop is constitutively repressed by the PI3K pathway. Our results could be relevant for disorders involving sustained GFAP overexpression in precursor cells, such as glioblastoma and Alexander disease.
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Affiliation(s)
- F Herrera
- Cellular Neurobiology Laboratory, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
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11
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Maher P. Methylglyoxal, advanced glycation end products and autism: Is there a connection? Med Hypotheses 2012; 78:548-52. [DOI: 10.1016/j.mehy.2012.01.032] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2011] [Revised: 12/22/2011] [Accepted: 01/16/2012] [Indexed: 12/30/2022]
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McIlwaine K, Cameron M, Readman E, Manwaring J, Maher P. The Effect of Patient BMI on Surgical Difficulty in Laparoscopic Gynaecological Surgery. J Minim Invasive Gynecol 2010. [DOI: 10.1016/j.jmig.2010.08.628] [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: 10/19/2022]
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McIlwaine K, Cameron M, Readman E, Manwaring J, Maher P. The effect of patient body mass index on surgical difficulty in gynaecological laparoscopy. ACTA ACUST UNITED AC 2010. [DOI: 10.1007/s10397-010-0636-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/29/2022]
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Lewerenz J, Dargusch R, Maher P. Lactacidosis modulates glutathione metabolism and oxidative glutamate toxicity. Akt Neurol 2009. [DOI: 10.1055/s-0029-1238667] [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: 10/20/2022]
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Mettler L, Maher P. Investigation of the Effectiveness of the Radially-Expanding Needle System, in Contrast to the Cutting Trocar in Enhancing Patient Recovery. MINIM INVASIV THER 2009. [DOI: 10.3109/13645700009093715] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Herrera F, Chen Q, Fischer WH, Maher P, Schubert DR. Synaptojanin-1 plays a key role in astrogliogenesis: possible relevance for Down's syndrome. Cell Death Differ 2009; 16:910-20. [PMID: 19282871 DOI: 10.1038/cdd.2009.24] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
There is increasing interest in gliogenesis as the relevance of glia to both brain development and pathology becomes better understood. However, little is known about this process. The use of multidimensional protein identification technology (MudPIT) to identify changes in phosphoprotein levels in rat neural precursor cells treated with cytokines or retinoic acid showed that phosphorylation of the catalytic subunit of phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K p110alpha) and dephosphorylation of the inositol phosphatase synaptojanin-1 were common to the gliogenic stimuli. Although PI3K was found to be involved in both neuro- and astrogliogenesis, synaptojanin-1 was specifically involved in astrogliogenesis of neural precursor cells. The role of synaptojanin-1 in astrogliogenesis was further confirmed by analysis of neuron- and glia-specific markers in synaptojanin-1 knockout mouse brain. Additional experiments showed that the Sac1-like phosphatase domain of synaptojanin-1 is responsible for the observed astrogliogenic effect. Our results strongly indicate that phosphatidylinositol metabolism plays a key role in astrogliogenesis. The relevance of our findings for Down's syndrome pathology is discussed.
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Affiliation(s)
- F Herrera
- Cellular Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA 92037-1099, USA
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Abstract
Cows are the main economic production units of Ireland's cattle industry. Therefore, demographic information, including overall numbers and survival rates, are relevant to the Irish agricultural industry. However, few data are available on the demographics of cows within a national population, either in Ireland or elsewhere, despite the recent development of comprehensive national cattle databases in many EU Member States. This study has sought: to determine the rate of cow culling from the national herd; to determine the rate of culling by type (dairy, beef), age, method of exit, date of exit and interval between last calving and exit; to calculate the national cow on-farm mortality rate; and to compare the Irish rates with published data from other countries. This work was conducted using data recorded in the national Cattle Movement Monitoring System (CMMS). Culling refers to the exit of cows from the national herd, as a result of death but regardless of reason, and cow-culling rate was calculated as the number of cow exits (as defined above) each year divided by the number of calf births in the same year. Culling rate was determined by type (dairy or beef), date of birth, method of exit (slaughter or on-farm death), month of exit and interval between last calving and exit. The average cow-culling rate during 2003 to 2006 was 19.6% (21.3% for dairy, 18% for beef). While comparisons must be treated with caution, it concluded that the overall rates of culling in Ireland fell within published internationally accepted norms. The on-farm mortality rate of 3.2-4.1% was similar to that reported in comparable studies.
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Affiliation(s)
- P Maher
- Department of Agriculture, Fisheries and Food, Kildare St,, Dublin 2.
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18
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Metzger J, Maher P, Wainscott M, Pepe PE, Delaney K. Injuries sustained by patients with behavioral disturbances brought to an emergency department in police custody. Crit Care 2008. [PMCID: PMC4088722 DOI: 10.1186/cc6572] [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: 04/03/2023] Open
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19
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Metzger J, Maher P, Wainscott M, Pepe P, Delaney K. Patterns of medical illness and injuries in emotionally disturbed patients brought to an emergency department in police custody. Crit Care 2008. [PMCID: PMC4088724 DOI: 10.1186/cc6574] [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: 11/12/2022] Open
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20
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Lapchak PA, Maher P, Schubert D, Zivin JA. Baicalein, an antioxidant 12/15-lipoxygenase inhibitor improves clinical rating scores following multiple infarct embolic strokes. Neuroscience 2007; 150:585-91. [PMID: 17942241 DOI: 10.1016/j.neuroscience.2007.09.033] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2007] [Revised: 09/10/2007] [Accepted: 09/18/2007] [Indexed: 11/30/2022]
Abstract
The present study assessed whether baicalein (5,6,7-trihydroxyflavone), a polyphenolic antioxidant 12/15-lipoxygenase inhibitor would attenuate oxidative cell death in vitro using a mouse hippocampal HT22 cell assay. Moreover, we determined if baicalein would be useful to attenuate behavioral deficits associated with multiple infarct ischemic events in vivo using a rabbit small clot embolic stroke model (RSCEM). Using HT22 cell in vitro, baicalein was shown to significantly promote cell survival with an estimated dose for 50% cell survival of 2 muM following incubation in the presence of iodoacetic acid (20 muM), an irreversible inhibitor of the glycolytic pathway that results in the free radical production, lipid peroxidation and cell death. Since baicalein was neuroprotective and attenuated iodoacetic acid (IAA) toxicity in vitro, we studied its effects in vivo in an embolic stroke model using behavioral measures as the endpoint. Quantal analysis for each treatment in the embolism model identifies the quantity of microclots (mg) that produce neurologic dysfunction in 50% of a group of animals (P(50)), with intervention considered neuroprotective if it increases the P(50) compared with controls. Baicalein (100 mg/kg, s.c.) injected 5 and 60 min post-embolization significantly (P<0.05) improved behavioral function. The calculated P(50) values were 2.85+/-0.64 mg (n=21) and 2.15+/-0.12 mg (n=14), respectively compared with 1.37+/-0.20 mg (n=23) for the control group. In conclusion, we have shown that baicalein effectively attenuated cell death in vitro using HT22 cells and also significantly reduced behavioral deficits in rabbits when given up to 1 h following an embolic stroke. The results suggest that baicalein, or derivatives of baicalein with multiple pharmacological activities may be useful to develop as novel treatments for acute ischemic stroke.
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Affiliation(s)
- P A Lapchak
- University of California, San Diego, Department of Neuroscience, La Jolla, CA 92093-0624, USA.
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21
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Torres JL, Lozano C, Maher P. Conjugation of catechins with cysteine generates antioxidant compounds with enhanced neuroprotective activity. Phytochemistry 2005; 66:2032-7. [PMID: 16153406 DOI: 10.1016/j.phytochem.2004.12.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2004] [Revised: 11/08/2004] [Indexed: 05/04/2023]
Abstract
Antioxidant compounds derived from the conjugation of (-)-epicatechin and (-)-epicatechin 3-O-gallate with cysteine and cysteine derivatives protected HT-22 nerve cells (EC50 between 36 and 65 microM) from death triggered by glutamate while underivatized (-)-epicatechin was almost inactive (EC50=610 microM). Differences in free radical scavenging capacity (DPPH assay) could not account for the improvement in neuroprotective activity upon derivatization of (-)-epicatechin with thiols. Moreover, while the gallate-containing compounds are more efficient radical scavengers than their non-galloylated counterparts, they are only equally or less potent as neuroprotective agents. Although all of the conjugates were able to scavenge mitochondrially generated reactive oxygen species (ROS) inside the cells, the majority of their neuroprotective activity appeared to be dependent upon their ability to maintain glutathione levels. These results suggest that a mechanism other than ROS scavenging is involved in the neuroprotective action exerted by the epicatechin conjugates.
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Affiliation(s)
- J L Torres
- Pure and Applied Biological Chemistry, Institute for Chemical and Environmental Research (IIQAB-CSIC), Jordi Girona 18-26, 08034 Barcelona, Spain.
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22
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23
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24
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Abstract
Extensive nerve cell death occurs during the development of the central nervous system as well as in episodes of trauma and in neurodegenerative disease. The mechanistic details of how these cells die are poorly understood. Here we describe a unique oxidative stress-induced programmed cell death pathway called oxytosis, and outline pharmacological approaches which interfere with its execution. Oxidative glutamate toxicity, in which exogenous glutamate inhibits cystine uptake through the cystine/glutamate antiporter leading to a depletion of glutathione, is used as an example of oxytosis. It is shown that there is a sequential requirement for de novo macromolecular synthesis, lipoxygenase activation, reactive oxygen species production, and the opening of cGMP-gated channels which allow the influx of extracellular calcium. The translation initiation factor elF2alpha plays a central role in this pathway by regulating the levels of glutathione. Finally, examples are given in which the reduction in glutathione, the production of reactive oxygen species, and calcium influx can be experimentally manipulated to prevent cell death. Data are reviewed which suggest that oxytosis may be involved in nerve cell death associated with nervous system trauma and disease.
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Affiliation(s)
- S Tan
- The Salk Institute for Biological Studies, Cellular Neurobiology Lab, La Jolla, CA 92037, USA
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25
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Chen Q, Yoshida H, Schubert D, Maher P, Mallory M, Masliah E. Presenilin binding protein is associated with neurofibrillary alterations in Alzheimer's disease and stimulates tau phosphorylation. Am J Pathol 2001; 159:1597-602. [PMID: 11696419 PMCID: PMC1867048 DOI: 10.1016/s0002-9440(10)63005-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
A novel presenilin binding protein, PBP, has recently been identified. PBP is localized to the particulate fraction of extracts of Alzheimer's disease brain but is found in the soluble fractions of brain from age matched normal controls. It is shown here that PBP is associated with neurofibrillary tangles in Alzheimer's disease brain. In addition, the expression of PBP increases the phosphorylation of tau in cultured cells. Therefore PBP may have a regulatory role in tau phosphorylation and in the genesis of neurofibrillary tangles.
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Affiliation(s)
- Q Chen
- Cellular Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, California 92037, USA
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26
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Abstract
The medical records of all women who underwent hysterectomy for benign disease performed between 1986 and 1995 were reviewed to ascertain the incidence of morbidity and mortality of abdominal, vaginal, and laparoscopically assisted vaginal hysterectomy at a university teaching hospital. A total of 1940 hysterectomies were performed during this period; 74% of hysterectomies were performed abdominally, 24% vaginally and 2% were laparoscopically assisted. In 80% of the patients uterine leiomyomas, adenomyosis, dysfunctional uterine bleeding or uterine prolapse were the indications for hysterectomy The overall complication rate was 44% for abdominal hysterectomy (AH) and 27.3% for vaginal hysterectomy (VH). An unintended major surgical procedure was required in 3% and 1% of women undergoing AH and VH respectively The rate of return to the operating room for haemostasis was 0.6% for AH and 0.2% for VH. The AH group was four times more likely than the VH group to require surgical intervention (36% versus 9%) at readmission. Vaginal hysterectomy was associated with a lower febrile morbidity and minor complication rate. Prophylactic antibiotics reduced the febrile morbidity for VH and AH by 50% (Student's t-test, p = 0.02) and 40% (Student's t-test, p < 0.001) respectively The overall mortality rate was 1.5 per 1000.
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Affiliation(s)
- N Varol
- Endosurgery Unit, Mercy Hospital for Women, East Melbourne, Victoria, Australia
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27
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Nielsen K, Gall D, Smith P, Kelly W, Yeo J, Kenny K, Heneghan T, McNamara S, Maher P, O'Connor J, Walsh B, Carroll J, Rojas X, Rojas F, Perez B, Wulff O, Buffoni L, Salustio E, Gregoret R, Samartino L, Dajer A, Luna-Martinez E. Fluorescence polarization assay for the diagnosis of bovine brucellosis: adaptation to field use. Vet Microbiol 2001; 80:163-70. [PMID: 11295336 DOI: 10.1016/s0378-1135(00)00386-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
A fluorescence polarization assay (FPA) was used to test whole blood samples prepared by mixing blood cells from cattle without exposure to Brucella abortus (B. abortus) with sera from animals with confirmed (bacteriologically) infection. A cut-off value between negative and positive values was initially established to be 87.2mP. This value was changed to 95mP to increase assay specificity without loss of sensitivity when testing blood samples from negative animals. The FPA technology was applied to whole blood samples in the field and to stored whole blood samples using two diluent buffers. Relative sensitivity and specificity values for the FPA performed in the field, based on buffered antigen plate agglutination test and competitive enzyme immunoassay results were 95.3 and 97.3%, respectively. However, to obtain maximum sensitivity and specificity, a cut-off value of 105mP was determined for fresh whole blood samples. The relative sensitivity and specificity values of the FPA when testing stored whole blood samples were 100% each using a 95mP cut-off.The usefulness of the FPA for testing whole blood samples in the field was demonstrated.
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Affiliation(s)
- K Nielsen
- Canadian Food Inspection Agency, Animal Diseases Research Institute, 3851 Fallowfield Rd., Nepean, Ontario, Canada K2H 8P9.
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28
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Maher P. How protein kinase C activation protects nerve cells from oxidative stress-induced cell death. J Neurosci 2001; 21:2929-38. [PMID: 11312276 PMCID: PMC6762555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023] Open
Abstract
Oxidative stress is implicated in the nerve cell death that occurs in a variety of neurological disorders, and the loss of protein kinase C (PKC) activity has been coupled to the severity of the damage. The functional relationship between stress, PKC, and cell death is, however, unknown. Using an immortalized hippocampal cell line that is particularly sensitive to oxidative stress, I show that activation of PKC by the phorbol ester tetradecanoylphorbol acetate (TPA) inhibits cell death via the stimulation of a complex protein phosphorylation pathway. TPA treatment leads to the rapid activation of extracellular signal-regulated kinase (ERK) and c-Jun NH2-terminal kinase (JNK), the inactivation of p38 mitogen-activated protein kinase (MAPK), and the downregulation of PKCdelta. Inhibition of either ERK or JNK activation blocks TPA-mediated protection, whereas p38 MAPK and PKCdelta inhibitors block stress-induced nerve cell death. Both p38 MAPK inactivation and JNK activation appear to be downstream of ERK because an agent that blocks ERK activation also blocks the modulation of these other MAP kinase family members by TPA treatment. Thus, the protection from oxidative stress afforded nerve cells by PKC activity requires the combined modulation of multiple enzyme pathways and suggests why the loss of PKC activity contributes to nerve cell death.
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Affiliation(s)
- P Maher
- Department of Cell Biology, The Scripps Research Institute, La Jolla, California 92037, USA.
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29
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Abstract
Oxidative stress and highly specific decreases in glutathione (GSH) are associated with nerve cell death in Parkinson's disease. Using an experimental nerve cell model for oxidative stress and an expression cloning strategy, a gene involved in oxidative stress-induced programmed cell death was identified which both mediates the cell death program and regulates GSH levels. Two stress-resistant clones were isolated which contain antisense gene fragments of the translation initiation factor (eIF)2alpha and express a low amount of eIF2alpha. Sensitivity is restored when the clones are transfected with full-length eIF2alpha; transfection of wild-type cells with the truncated eIF2alpha gene confers resistance. The phosphorylation of eIF2alpha also results in resistance to oxidative stress. In wild-type cells, oxidative stress results in rapid GSH depletion, a large increase in peroxide levels, and an influx of Ca(2+). In contrast, the resistant clones maintain high GSH levels and show no elevation in peroxides or Ca(2+) when stressed, and the GSH synthetic enzyme gamma-glutamyl cysteine synthetase (gammaGCS) is elevated. The change in gammaGCS is regulated by a translational mechanism. Therefore, eIF2alpha is a critical regulatory factor in the response of nerve cells to oxidative stress and in the control of the major intracellular antioxidant, GSH, and may play a central role in the many neurodegenerative diseases associated with oxidative stress.
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Affiliation(s)
- S Tan
- Cellular Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, California 92037, USA
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30
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Piotrowicz RS, Ding L, Maher P, Levin EG. Inhibition of cell migration by 24-kDa fibroblast growth factor-2 is dependent upon the estrogen receptor. J Biol Chem 2001; 276:3963-70. [PMID: 11083859 DOI: 10.1074/jbc.m004868200] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [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: 11/06/2022] Open
Abstract
The single-copy gene for fibroblast growth factor-2 (FGF-2) encodes for multiple forms of the protein with molecular masses of 24, 22.5, 22, and 18 kDa. We reported previously that the 24-22-kDa FGF-2 forms inhibit the migration of endothelial and MCF-7 cells by 50% and 70%, respectively. Here we show that this inhibition of migration is mediated by the estrogen receptor (ER). We have found that depletion of the receptor in either cell line abrogates the inhibitory activity of 24-kDa FGF-2 while re-introduction of the ER into deficient cells once again promotes the inhibitory response. To determine whether exposure to 24-kDa FGF-2 resulted in the activation of the estrogen receptor, 3T3 cells were cotransfected with estrogen receptor cDNA and an estrogen regulatory element-luciferase gene reporter construct and treated with 24- and 18-kDa FGF-2. The high molecular weight form stimulated luciferase activity 5-fold while 18-kDa FGF-2 at the same concentration had no effect. Treatment of ER-positive MCF-7 cells transfected with the reporter construct only showed the same results. Inclusion of the pure estrogen antagonist ICI 182,780 blocked the increase in luciferase activity by 24-kDa FGF-2, further indicating that the response was estrogen receptor dependent. Expression of dominant negative FGF receptor 1 inhibited ER activation, indicating that this was the cell surface receptor mediating the effect. Although growth factor-dependent activation of the ER was reported to require mitogen-activated protein kinase-induced phosphorylation at Ser(118) in COS and HeLa cells, this mechanism is not involved with the activation by 24-kDa FGF-2. These results suggest that the addition of 55 amino acids to the amino-terminal end of 18-kDa FGF-2 by alternative translation alters FGF-2 function and allows for the activation of a second signaling pathway involving the estrogen receptor.
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Affiliation(s)
- R S Piotrowicz
- Department of Cell Biology, Scripps Research Institute, La Jolla, California 92037, USA
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31
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Peng H, Moffett J, Myers J, Fang X, Stachowiak EK, Maher P, Kratz E, Hines J, Fluharty SJ, Mizukoshi E, Bloom DC, Stachowiak MK. Novel nuclear signaling pathway mediates activation of fibroblast growth factor-2 gene by type 1 and type 2 angiotensin II receptors. Mol Biol Cell 2001; 12:449-62. [PMID: 11179427 PMCID: PMC30955 DOI: 10.1091/mbc.12.2.449] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.6] [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: 01/02/2023] Open
Abstract
In bovine adrenal medullary cells synergistically acting type 1 and type 2 angiotensin II (AII) receptors activate the fibroblast growth factor-2 (FGF-2) gene through a unique AII-responsive promoter element. Both the type 1 and type 2 AII receptors and the downstream cyclic adenosine 1',3'-monophosphate- and protein kinase C-dependent signaling pathways activate the FGF-2 promoter through a novel signal-transducing mechanism. This mechanism, which we have named integrative nuclear FGF receptor-1 signaling, involves the nuclear translocation of FGF receptor-1 and its subsequent transactivation of the AII-responsive element in the FGF-2 promoter.
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Affiliation(s)
- H Peng
- Molecular and Structural Neurobiology and Gene Therapy Program, State University of New York, Buffalo, New York 14214, USA
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32
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Abstract
Free radicals and reactive oxygen species (ROS) are involved in a variety of different cellular processes ranging from apoptosis and necrosis to cell proliferation and carcinogenesis. Cells contain multiple sites for ROS production and a few mechanisms for their degradation. Which of these sites is activated by a given stimulus may play a role in dictating the subsequent downstream effects of the ROS generated on cellular function. Even when the ultimate outcome is similar, such as when ROS production leads to cell death, the specific cellular changes can be quite different depending on the initial stimulus and the type of cell involved. These data, along with the evidence that ROS can modify a number of intracellular signaling pathways including protein phosphatases, protein kinases and transcription factors, suggest that the majority of the effects of ROS on cells are through their actions on signaling pathways rather than via nonspecific damage of intracellular macromolecules.
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Affiliation(s)
- P Maher
- The Scripps Research Institute, Department of Cell Biology, La Jolla, California 92037, USA.
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33
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Abstract
Intestinal involvement by endometriosis traditionally required open laparotomy for bowel resection and anastomosis. Operative laparoscopy may offer the most effective form of treatment for these women. Two women with endometriosis of the rectum and right hemicolon, respectively, underwent transvaginal resection of the rectum and laparotomy for hemicolectomy, assisted by laparoscopy. The only morbidity was postoperative ileus in the former patient. Both women were asymptomatic at the 6-week postoperative visit.
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Affiliation(s)
- N Varol
- Royal Prince Alfred Hospital Medical Centre, Suite 404, Level 4, 100 Carillon Avenue, Newtown, N.S.W. 2042, Australia
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34
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Abstract
Western health professionals often experience difficulties in service delivery to Aboriginal people because of the disparity between Aboriginal and Western health belief systems. This article reviews the literature which considers 'traditional' Aboriginal health beliefs and medical systems. The traditional Aboriginal model of illness causation emphasises social and spiritual dysfunction as a cause of illness. Supernatural intervention is regarded as the main cause of serious illness. There are gender divisions in Aboriginal society that impact on the delivery of Western healthcare. Management strategies such as preventative care, bush medicine, and the role of traditional healers are discussed. These belief systems are considered with particular reference to their interactions and implications with regard to the Western medical system. This information provides a framework to allow improved understanding by health professionals of the health-related decisions made by Aboriginal people.
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Affiliation(s)
- P Maher
- Northern Rehabilitation Network, Royal Darwin Hospital, Casuarina, Northern Territory, Australia.
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35
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Maher P. p38 mitogen-activated protein kinase activation is required for fibroblast growth factor-2-stimulated cell proliferation but not differentiation. J Biol Chem 1999; 274:17491-8. [PMID: 10364180 DOI: 10.1074/jbc.274.25.17491] [Citation(s) in RCA: 121] [Impact Index Per Article: 4.8] [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: 11/06/2022] Open
Abstract
Basic fibroblast growth factor (FGF-2) is a member of a family of polypeptides that have roles in a wide range of biological processes. To determine why different cell types show distinct responses to treatment with FGF-2, the array of FGF receptors present on the surface of a cell which differentiates in response to FGF-2 (PC12 cells) was compared with that present on the surface of a cell that proliferates in response to FGF-2 (Swiss 3T3 fibroblasts). Both cell types express exclusively FGFR1, suggesting that there are cell type-specific FGFR1 signaling pathways. Since mitogen-activated protein kinases function as mediators of cellular responses to a variety of stimuli, the roles of these proteins in FGF-mediated responses were examined. FGF-2 activates extracellular signal-regulated kinases with similar kinetics in both fibroblasts and PC12 cells, and a specific inhibitor of extracellular signal-regulated kinase activation blocks differentiation but has little effect on proliferation. In contrast, while p38 mitogen-activated protein kinase is activated weakly and transiently in PC12 cells treated with FGF-2, a much stronger and sustained activation of this kinase is seen in FGF-2-treated fibroblasts. Furthermore, specific inhibitors of this kinase block proliferation but have no effect on differentiation. This effect on proliferation is specific for FGF-2 since the same concentrations of inhibitors have little or no effect on proliferation induced by serum.
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Affiliation(s)
- P Maher
- Department of Cell Biology, Scripps Research Institute, La Jolla, California 92037, USA
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36
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Abstract
We retrospectively reviewed the medical records of 13 women who underwent laparoscopically-assisted vaginal hysterectomy (LAVH) where the uterus weighed 500 g or more. LAVH was successfully performed in 10 of these 13 women for whom the mean uterine weight was 619 g, mean operating time 99 minutes, and mean postoperative hospital stay 3.7 days. One of the 3 women who underwent abdominal hysterectomy required blood transfusion for intraoperative bleeding. There was no febrile or other operative morbidity associated with any patient. As up to 75% of hysterectomies are performed abdominally, LAVH may replace many abdominal hysterectomies for large fibroid uteri when vaginal hysterectomy is not feasible.
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Affiliation(s)
- N Salmanli
- Endosurgery Unit, Mercy Hospital for Women, East Melbourne, Victoria
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37
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Abstract
This review was undertaken to ascertain whether the low usage of laparoscopic surgery in gynaecology resulted from unacceptable complication rates and long operating times. The safety and efficacy of laparoscopic surgery has been compared to that of laparotomy. Reports of controlled or comparative trials of laparoscopic gynaecological surgery for adhesions, infertility, ectopic pregnancy, oophorectomy, myomectomy and laparoscopically-assisted vaginal hysterectomy (LAVH) have been reviewed between 1984 and 1997. Although further multicentre controlled trials may improve the assessment of complication rates for both laparotomy and laparoscopy procedures, laparoscopy appears to be as safe as laparotomy and generally has the advantage of shorter hospital stay and earlier return to normal activities. Except for LAVH, operating times of laparoscopic surgery are similar to that of laparotomy.
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Affiliation(s)
- C Wood
- Melbourne Gynoscopy, Victoria, Australia
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38
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Abstract
Oxidative stress is implicated in a number of neurological disorders including stroke, Parkinson's disease, and Alzheimer's disease. To study the effects of oxidative stress on neuronal cells, we have used an immortalized mouse hippocampal cell line (HT-22) that is particularly sensitive to glutamate. In these cells, glutamate competes for cystine uptake, leading to a reduction in glutathione and, ultimately, cell death. As it has been reported that protein kinase C activation inhibits glutamate toxicity in these cells and is also associated with the inhibition of apoptosis in other cell types, we asked if glutamate toxicity was via apoptosis. Morphologically, glutamate-treated cells underwent plasma membrane blebbing and cell shrinkage, but no DNA fragmentation was observed. At the ultrastructural level, there was damage to mitochondria and other organelles although the nuclei remained intact. Protein and RNA synthesis inhibitors as well as certain protease inhibitors protected the cells from glutamate toxicity. Both the macromolecular synthesis inhibitors and the protease inhibitors had to be added relatively soon after the addition of glutamate, suggesting that protein synthesis and protease activation are early and distinct steps in the cell death pathway. Thus, the oxidative stress brought about by treatment with glutamate initiates a series of events that lead to a form of cell death distinct from either necrosis or apoptosis.
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Affiliation(s)
- S Tan
- The Scripps Research Institute, La Jolla, California 92037, USA
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39
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Abstract
Allergic reactions tend to be easily recognized and treated, but methemoglobinemia is a rare, life-threatening complication of topical anesthesia of which our staff was unaware until recently. Team work prevented a patient fatality. Directives to alert the staff to suspect methemoglobinemia in patients who develop cyanosis and decreased oxygen saturation levels after administration of topical anesthesia despite administration of oxygen will prevent fatalities in the future.
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Affiliation(s)
- P Maher
- St. Joseph Health Center-Endoscopy Suite, St. Charles, MO 63301, USA
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40
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Abstract
Phosphatidylcholine-specific phospholipase C (PC-PLC) is a necessary intermediate in transducing apoptotic signals for tumor necrosis factor and Fas/Apo-1 ligands in nonneuronal cells. The data presented here show that PC-PLC also is required in oxidative glutamate-induced programmed cell death of both immature cortical neurons and a hippocampal nerve cell line, HT22. In oxidative glutamate toxicity, which is distinct from excitotoxicity, glutamate interferes with cystine uptake by blocking the cystine/glutamate antiporter, indirectly causing a depletion of intracellular glutathione. A PC-PLC inhibitor blocks oxidative glutamate toxicity, and exogenous PC-PLC potentiates glutamate toxicity. The inhibition of PC-PLC uncouples the cystine uptake from glutamate inhibition, allowing the maintenance of glutathione synthesis and cell viability. These data suggest that PC-PLC modulates neuronal cell death through a mechanism that is distinct from that involved in nonneuronal apoptosis.
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Affiliation(s)
- Y Li
- Cellular Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA
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41
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Tan S, Sagara Y, Liu Y, Maher P, Schubert D. The regulation of reactive oxygen species production during programmed cell death. J Cell Biol 1998; 141:1423-32. [PMID: 9628898 PMCID: PMC2132785 DOI: 10.1083/jcb.141.6.1423] [Citation(s) in RCA: 585] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/1998] [Revised: 05/04/1998] [Indexed: 02/07/2023] Open
Abstract
Reactive oxygen species (ROS) are thought to be involved in many forms of programmed cell death. The role of ROS in cell death caused by oxidative glutamate toxicity was studied in an immortalized mouse hippocampal cell line (HT22). The causal relationship between ROS production and glutathione (GSH) levels, gene expression, caspase activity, and cytosolic Ca2+ concentration was examined. An initial 5-10-fold increase in ROS after glutamate addition is temporally correlated with GSH depletion. This early increase is followed by an explosive burst of ROS production to 200-400-fold above control values. The source of this burst is the mitochondrial electron transport chain, while only 5-10% of the maximum ROS production is caused by GSH depletion. Macromolecular synthesis inhibitors as well as Ac-YVAD-cmk, an interleukin 1beta-converting enzyme protease inhibitor, block the late burst of ROS production and protect HT22 cells from glutamate toxicity when added early in the death program. Inhibition of intracellular Ca2+ cycling and the influx of extracellular Ca2+ also blocks maximum ROS production and protects the cells. The conclusion is that GSH depletion is not sufficient to cause the maximal mitochondrial ROS production, and that there is an early requirement for protease activation, changes in gene expression, and a late requirement for Ca2+ mobilization.
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Affiliation(s)
- S Tan
- Cellular Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, California 92037, USA
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42
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Abstract
Endoscopic surgery is able to replace most abdominal operations in the surgical treatment of uterine leiomyomas. The use of gonadotrophin hormone-releasing hormone analogues, arterial embolization, hysteroscopy, new techniques of morcellation, laparo-vaginal gasless laparoscopy and laparoscopic mini-laparotomy have enabled the avoidance of laparotomy incisions in most patients. The previous disadvantages of laparoscopy, namely a prolonged operating time, excessive bleeding and inadequate closure, have been overcome. Case and controlled studies have demonstrated the effectiveness of endoscopy in fibroid treatment. The surgical techniques require advanced endoscopic training.
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Affiliation(s)
- C Wood
- Mercy Hospital for Women, East Melbourne, Victoria, Australia
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43
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Abstract
Oxidative stress is implicated in several pathologies such as AIDS, Alzheimer's disease, and Parkinson's disease, as well as in normal aging. As a model system to study the response of cells to oxidative insults, glutamate toxicity on a mouse nerve cell line, HT-22, was examined. Glutamate exposure kills HT-22 via a nonreceptor-mediated oxidative pathway by blocking cystine uptake and causing depletion of intracellular glutathione (GSH), leading to the accumulation of reactive oxygen species and, ultimately, apoptotic cell death. Several HT-22 subclones that are 10-fold resistant to exogenous glutamate were isolated and the mechanisms involved in resistance characterized. The expression levels of neither heat shock proteins nor apoptosis-related proteins are changed in the resistant cells. In contrast, the antioxidant enzyme catalase, but not glutathione peroxidase nor superoxide dismutase, is more highly expressed in the resistant than in the parental cells. In addition, the resistant cells have enhanced rates of GSH regeneration due to higher activities of the GSH metabolic enzymes gamma-glutamylcysteine synthetase and GSH reductase, and GSH S-transferases activities are also elevated. As a consequence of these alterations, the glutamate resistant cells are also more resistant to organic hydroperoxides and anticancer drugs that affect these GSH enzymes. These results indicate that resistance to apoptotic oxidative stress may be acquired by coordinated changes in multiple antioxidant pathways.
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Affiliation(s)
- Y Sagara
- The Salk Institute for Biological Studies, La Jolla, San Diego, CA 92186-5800, USA.
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44
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Abstract
An open prospective observational study was performed, aiming to measure symptom severity following operative gynaecological laparoscopy and explore any associated factors. Women having concomitant procedures were excluded. Each woman had standardized analgesia, completed a symptom diary for 7 days postoperation, and had a standardized form completed by the surgeon detailing the operation. Back pain, nausea and vaginal pain were found to not be of clinical significance. Cutting major vessels, ligaments, vagina or ovary had major impacts on postoperative symptoms. In the presence of a standardized analgesic regimen, symptoms did not resolve for at least 5 days.
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Affiliation(s)
- M Healey
- Mercy Hospital for Women, East Melbourne, Victoria
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45
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Abstract
It is likely that amyloid beta-protein (A beta) mediates nerve cell death in Alzheimer's disease (AD). Some nerve cell populations, however, remain undamaged in AD brain. To understand the biochemical basis for resistance to A beta toxicity, a series of cell lines were isolated which are resistant to A beta toxicity. It is shown that a major component of the resistance mechanism is the transcriptional elevation of two H2O2 degrading enzymes, glutathione peroxidase and catalase. These data support other evidence for the role of oxidative damage in A beta toxicity, and suggest strategies for clinical approaches to the disease.
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Affiliation(s)
- Y Sagara
- Salk Institute for Biological Studies, La Jolla, CA 92037, USA
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46
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Stachowiak MK, Moffett J, Maher P, Tucholski J, Stachowiak EK. Growth factor regulation of cell growth and proliferation in the nervous system. A new intracrine nuclear mechanism. Mol Neurobiol 1997; 15:257-83. [PMID: 9457702 DOI: 10.1007/bf02740663] [Citation(s) in RCA: 89] [Impact Index Per Article: 3.3] [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: 02/06/2023]
Abstract
This article discusses a novel intracrine mechanism of growth-factor action in the nervous system whereby fibroblast growth factor-2 (FGF-2) and its receptor accumulate in the cell nucleus and act as mediators in the control of cell growth and proliferation. In human and rat brain the levels and subcellular localization of FGF-2 differ between quiescent and reactive astrocytes. Quiescent cells express a low level of FGF-2, which is located predominantly within the cytoplasm. In reactive astrocytes, the expression of FGF-2 increases and the proteins are found in both the cytoplasm and nucleus. In glioma tumors, FGF-2 is overexpressed in the nuclei of neoplastic cells. Similar changes in FGF-2 expression and localization are found in vitro. The nuclear accumulation of FGF-2 reflects a transient activation of the FGF-2 gene by potentially novel transactivating factors interacting with an upstream regulatory promoter region. In parallel with FGF-2, the nuclei of astrocytes contain the high-affinity FGF-2 receptor, FGFR1. Nuclear FGFR1 is full length, retains kinase activity, and is localized within the nuclear interior in association with the nuclear matrix. Transfection of either FGF-2 or FGFR1 into cells that do not normally express these proteins results in their nuclear accumulation and concomitant increases in cell proliferation. A similar regulation of nuclear FGF-2 and FGFR1 is observed in neural crestderived adrenal medullary cells and of FGF-2 in the nuclei of cerebellar neurons. Thus, the regulation of the nuclear content of FGF-2 and FGFR1 could serve as a novel mechanism controlling growth and proliferation of glial and neuronal cells.
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Affiliation(s)
- M K Stachowiak
- Laboratory of Molecular Neurobiology, Barrow Neurological Institute, Phoenix, AZ, USA
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47
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Abstract
Glutathione depletion occurs in several forms of apoptosis and is associated with Parkinson's disease and HIV toxicity. The neurotransmitter glutamate kills immature cortical neurons and a hippocampal nerve cell line via an oxidative pathway associated with glutathione depletion. It is shown here that soluble guanylyl cyclase (sGC) activity is required for nerve cell death caused by glutathione depletion. Inhibitors of sGC block glutamate toxicity and a cGMP analogue potentiates cell death. Glutamate also induces an elevation of cGMP that occurs late in the cell death pathway. The resultant cGMP modulates the increase in intracellular calcium that precedes cell death because sGC inhibitors prevent calcium elevation and the cGMP analogue potentiates the increase in intracellular calcium. These results suggest that the final pathway of glutamate induced nerve cell death is through a cGMP-modulated calcium channel.
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Affiliation(s)
- Y Li
- Cellular Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, California 92037, USA
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48
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Abstract
The increased use of blood transfusion, ultrasound evidence of postsurgical haematoma, the frequency of postoperative febrile morbidity of unknown cause and reports of these complications in large series which contain both abdominal and vaginal hysterectomy over the last 25 years, suggests that bleeding may be more common after vaginal hysterectomy. We performed laparoscopy routinely after vaginal hysterectomy in 50 patients. The frequency of bleeding was 48%, consistent with other studies ranging from 30 to 98%. Arterial bleeding from a branch of the uterine or vaginal artery occurred in 20%. The frequency of bleeding was not related to uterine size, ranging from normal to that equivalent in size to that of a pregnancy of 18 weeks' gestation. The most common site of bleeding was the vaginal vault. Liberal definitions of haemorrhage, possible emphasis in speed in performing hysterectomy, and difficulty in visualizing and ligating major and minor blood vessels, may have contributed to the increased frequency of bleeding reported after vaginal hysterectomy. Haemostasis is more easily obtained at laparoscopic surgery because of magnification, close inspection, routine use of suction irrigation and bipolar electrocoagulation. Routine laparoscopy at the completion of vaginal hysterectomy is recommended. New and improved methods of vessel closure are also required. Attitudes to haemorrhage during hysterectomy require change to further reduce the use of blood transfusion.
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Affiliation(s)
- C Wood
- Melbourne Gynoscopy and Endosurgical Unit, Mercy Hospital for Women, Melbourne
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49
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Abstract
Recent evidence suggests that amyloid beta protein (A beta) mediates the neurotoxicity observed in Alzheimer's disease (AD). Little is known, however, about the cytotoxic pathway leading to nerve cell death. Using a rat brain cell line which is sensitive to A beta, it is shown that a 50-60 kDa protein becomes more phosphorylated when cells are exposed to A beta. Several kinase and phosphatase inhibitors block both the increase in phosphorylation of the 50-60 kDa protein and A beta toxicity. In contrast, a tyrosine kinase inhibitor blocks toxicity at a step which is distinct from the phosphorylation of this protein. A beta also causes a general increase in overall phosphatase activity. It is therefore likely that a protein phosphorylation cascade is involved in A beta toxicity.
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Affiliation(s)
- S Tan
- The Salk Institute for Biological Studies, La Jolla, CA 92037, USA
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50
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Abstract
An early and highly specific decrease in glutathione (GSH) in the substantia nigra is associated with Parkinson's disease, and low levels of GSH lead to the degeneration of cultured dopaminergic neurons. Using immature cortical neurons and a clonal nerve cell line, it is shown that a decrease in GSH triggers the activation of neuronal 12-lipoxygenase (12-LOX), which leads to the production of peroxides, the influx of Ca2+, and ultimately to cell death. The supporting evidence includes: 1) inhibitors of arachidonate metabolism and 12-LOX block cell death induced by GSH depletion; 2) there is an increase in 12-LOX activity and a membrane translocation in HT22 cells, and an induction of the enzyme in primary cortical neurons following the reduction of GSH; 3) 12-LOX is directly inhibited by GSH; and 4) exogenous arachidonic acid potentiates cell death. These data show that the LOX pathway is a critical intermediate in at least some forms of neuronal degeneration.
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Affiliation(s)
- Y Li
- Cellular Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, California 92037, USA
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