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Izulla P, Wagai JN, Akelo V, Ombeva A, Okeri E, Onyango D, Omore R, Fuller S, Khagayi S, Were J, Anderson SA, Wong HL, Tippett Barr BA. Vaccine safety surveillance in Kenya using GAIA standards: A feasibility assessment of existing national and subnational research and program systems. Vaccine 2023; 41:5722-5729. [PMID: 37550143 DOI: 10.1016/j.vaccine.2023.07.063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Revised: 04/17/2023] [Accepted: 07/26/2023] [Indexed: 08/09/2023]
Abstract
BACKGROUND Active surveillance systems for monitoring vaccine safety among pregnant women address some of the limitations of a current passive surveillance approach utilized in low- and middle-income countries (LMIC). However, few active surveillance systems in LMIC exist. Our study assessed the feasibility of utilizing three existing data collection systems in Kenya for active surveillance of maternal immunization and to assess the applicability of Global Alignment of Immunization Safety Assessment in pregnancy (GAIA) case definitions that were initially developed for clinical trials within these systems. METHODS We assessed applicability of GAIA case definition for maternal Tetanus Toxoid exposure, stillbirth, low birth weight, small for gestational age, Neonatal Invasive Blood Stream Infection (NIBSI), prematurity and neonatal death in two routine web-based health information systems (Kenya EMR and DHIS-2), and a web-based population-based pregnancy research platform (ANCOV1) in Kenya. RESULTS All three HIS were capable of reporting selected outcomes to varying degrees of GAIA certainty. The ANCOV platform was the most robust in collecting and collating clinical data for effective maternal pharmacovigilance. The utilization of facility- and district-aggregated data limits the usefulness of DHIS-2 in pharmacovigilance as currently operationalized. While the Kenya EMR contained individual level data and meets the key considerations for effective pharmacovigilance, it was used primarily for HIV care and treatment records in a small proportion of health facilities and would require additional resources to expand to all antenatal care facilities and to link maternal and infant records. DISCUSSION Population-based research studies may offer a responsive short-term option for implementing maternal vaccine pharmacovigilance in LMICs. However, the foundation exists for long-term capacity building within the national health electronic data systems to provide this critical service as well as ensure participation of the country in international studies on maternal vaccine safety.
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Affiliation(s)
- P Izulla
- Adroitz Consultants, Nairobi, Kenya.
| | | | - V Akelo
- US Centers for Disease Control and Prevention, Kisumu, Kenya
| | - A Ombeva
- Adroitz Consultants, Nairobi, Kenya
| | - E Okeri
- Adroitz Consultants, Nairobi, Kenya
| | - D Onyango
- Kisumu County Department of Health, Kisumu, Kenya
| | - R Omore
- Kenya Medical Research Institute Center for Global Health Research, Kisumu, Kenya
| | - S Fuller
- US Centers for Disease Control and Prevention, Kisumu, Kenya
| | - S Khagayi
- Kenya Medical Research Institute Center for Global Health Research, Kisumu, Kenya
| | - J Were
- Kenya Medical Research Institute Center for Global Health Research, Kisumu, Kenya
| | - S A Anderson
- US Food and Drug Administration, Silver Spring, USA
| | - H L Wong
- US Food and Drug Administration, Silver Spring, USA
| | - B A Tippett Barr
- US Centers for Disease Control and Prevention, Kisumu, Kenya; Nyanja Health Research Institute, Salima, Malawi
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2
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Votava JA, Reese SR, Deck KM, Nizzi CP, Anderson SA, Djamali A, Eisenstein RS. Dysregulation of the sensory and regulatory pathways controlling cellular iron metabolism in unilateral obstructive nephropathy. Am J Physiol Renal Physiol 2022; 322:F89-F103. [PMID: 34843656 PMCID: PMC8742730 DOI: 10.1152/ajprenal.00537.2020] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 11/16/2021] [Accepted: 11/23/2021] [Indexed: 01/03/2023] Open
Abstract
Chronic kidney disease involves disturbances in iron metabolism including anemia caused by insufficient erythropoietin (EPO) production. However, underlying mechanisms responsible for the dysregulation of cellular iron metabolism are incompletely defined. Using the unilateral ureteral obstruction (UUO) model in Irp1+/+ and Irp1-/- mice, we asked if iron regulatory proteins (IRPs), the central regulators of cellular iron metabolism and suppressors of EPO production, contribute to the etiology of anemia in kidney failure. We identified a significant reduction in IRP protein level and RNA binding activity that associates with a loss of the iron uptake protein transferrin receptor 1 (TfR1), increased expression of the iron storage protein subunits H- and L-ferritin, and a low but overall variable level of stainable iron in the obstructed kidney. This reduction in IRP RNA binding activity and ferritin RNA levels suggests the concomitant rise in ferritin expression and iron content in kidney failure is IRP dependent. In contrast, the reduction in the Epo mRNA level in the obstructed kidney was not rescued by genetic ablation of IRP1, suggesting disruption of normal hypoxia-inducible factor (HIF)-2α regulation. Furthermore, reduced expression of some HIF-α target genes in UUO occurred in the face of increased expression of HIF-α proteins and prolyl hydroxylases 2 and 1, the latter of which is not known to be HIF-α mediated. Our results suggest that the IRP system drives changes in cellular iron metabolism that are associated with kidney failure in UUO but that the impact of IRPs on EPO production is overridden by disrupted hypoxia signaling.NEW & NOTEWORTHY This study demonstrates that iron metabolism and hypoxia signaling are dysregulated in unilateral obstructive nephropathy. Expression of iron regulatory proteins (IRPs), central regulators of cellular iron metabolism, and the iron uptake (transferrin receptor 1) and storage (ferritins) proteins they target is strongly altered. This suggests a role of IRPs in previously observed changes in iron metabolism in progressive renal disease. Hypoxia signaling is disrupted and appeared to dominate the action of IRP1 in controlling erythropoietin expression.
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Affiliation(s)
- James A Votava
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, Wisconsin
| | - Shannon R Reese
- Division of Nephrology, Department of Medicine, University of Wisconsin-Madison, Madison, Wisconsin
| | - Kathryn M Deck
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, Wisconsin
| | - Christopher P Nizzi
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, Wisconsin
| | - Sheila A Anderson
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, Wisconsin
| | - Arjang Djamali
- Division of Nephrology, Department of Medicine, University of Wisconsin-Madison, Madison, Wisconsin
- Division of Transplant, Department of Surgery, University of Wisconsin-Madison, Madison, Wisconsin
| | - Richard S Eisenstein
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, Wisconsin
- Morgridge Institute for Research, University of Wisconsin-Madison, Madison, Wisconsin
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3
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Garza KR, Clarke SL, Ho YH, Bruss MD, Vasanthakumar A, Anderson SA, Eisenstein RS. Differential translational control of 5' IRE-containing mRNA in response to dietary iron deficiency and acute iron overload. Metallomics 2020; 12:2186-2198. [PMID: 33325950 DOI: 10.1039/d0mt00192a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Iron regulatory proteins (IRPs) are iron-responsive RNA binding proteins that dictate changes in cellular iron metabolism in animal cells by controlling the fate of mRNAs containing iron responsive elements (IREs). IRPs have broader physiological roles as some targeted mRNAs encode proteins with functions beyond iron metabolism suggesting hierarchical regulation of IRP-targeted mRNAs. We observe that the translational regulation of IRP-targeted mRNAs encoding iron storage (L- and H-ferritins) and export (ferroportin) proteins have different set-points of iron responsiveness compared to that for the TCA cycle enzyme mitochondrial aconitase. The ferritins and ferroportin mRNA were largely translationally repressed in the liver of rats fed a normal diet whereas mitochondrial aconitase mRNA is primarily polysome bound. Consequently, acute iron overload increases polysome association of H- and L-ferritin and ferroportin mRNAs while mitochondrial aconitase mRNA showed little stimulation. Conversely, mitochondrial aconitase mRNA is most responsive in iron deficiency. These differences in regulation were associated with a faster off-rate of IRP1 for the IRE of mitochondrial aconitase in comparison to that of L-ferritin. Thus, hierarchical control of mRNA translation by IRPs involves selective control of cellular functions acting at different states of cellular iron status and that are critical for adaptations to iron deficiency or prevention of iron toxicity.
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Affiliation(s)
- Kerry R Garza
- University of Wisconsin-Madison, Department of Nutritional Sciences, 1415 Linden Drive, Madison, WI 53706, USA.
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Avalos Hernandez SR, Anderson SA, Dal Zotto V. Checkpoint Inhibitor-Induced Colitis: A Case Series. Am J Clin Pathol 2020. [DOI: 10.1093/ajcp/aqaa161.137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Introduction/Objective
Checkpoint inhibitors are novel immune-stimulating antibodies that have revolutionized the management and prognosis of several malignancies. The primary targets are cytotoxic T-lymphocyte–associated antigen-4 (anti-CTLA-4; e.g. pembrolizumab) and programmed cell death-1 receptor (anti-PD-1; e.g. ipilimumab and nivolumab). In spite of the significant advantages, many immune-related adverse effects have been identified. One of which is checkpoint inhibitor-induced colitis (CIC). Although there is awareness of the histopathologic features of anti- CTLA-4 induced colitis, there is much to be discovered about the pathologic features of anti-PD-1 colitis.
Methods
We herein report three cases of CIC. There were two women and 1 male (age range, 50 to 73-years-old, mean 64-years-old) who presented with diarrhea and/or hematochezia after multiple cycles of pembrolizumab or ipilimumab/ nivolumab combination therapy. Endoscopic examination was abnormal in all of these cases.
Results
The histologic features were similar in two cases, with moderate active chronic colitis and one case with focal active colitis. Two of the three patient were given steroids in addition to their regular medications with symptom improvement. One patient was removed off all medications and enrolled into hospice due to disease progression. CIC has been an increasingly recognized immune-related adverse effect that has a wide spectrum of clinical presentations ranging from mild diarrhea and abdominal pain to severe colitis and intestinal perforation. However, it is thought to be underestimated. Histologically, CIC can mimic inflammatory bowel disease, microscopic colitis and active colitis. Our cases showed histopathologic features mimicking those of ulcerative colitis.
Conclusion
Awareness of CIC is crucial for the multidisciplinary management essential for these patients. The histopathologic pattern coupled with the clinical history can allow pathologists to confirm the diagnosis of CIC and facilitate timely diagnosis and treatment.
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Affiliation(s)
| | - S A Anderson
- Pathology, University of South Alabama, Mobile, Alabama, UNITED STATES
| | - V Dal Zotto
- Pathology, University of South Alabama, Mobile, Alabama, UNITED STATES
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Anderson SA, Liu S, Galliani C, Weaver K. Isolated Congenital Bronchoesophageal Fistula in a Pediatric Patient: Case Report. Am J Clin Pathol 2020. [DOI: 10.1093/ajcp/aqaa161.091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Abstract
Introduction/Objective
Congenital bronchoesophageal fistula (BEF) results from an undue passageway caudal to the foregut lung anlage. BEF may be associated with esophageal atresia and commonly involves the right lung. Herein we present a pediatric case of isolated congenital BEF masqueraded by severe dyspeptic symptoms.
Methods
A five-year-old child with a longstanding history of gastroesophageal reflux was hospitalized because of acute onset sharp lower chest/epigastric abdominal pain associated with emesis. Imaging disclosed a left lung abscess and empyema that responded to intravenous antibiotics, chest tPA instillation and drainage. After resolution of her empyema, she experienced severe dysphagia, chocking sensation, vomiting, and intermittent hematemesis. Esophogram disclosed a fistulous tract to the left lower chest cavity. Esophagoscopy revealed severe esophagitis and a stricture just proximal to a 0.6 to 0.8 cm ostium of a fistulous tract at 26 cm from the incisors, 2 cm above the gastroesophageal junction.
Results
A 103 g, 12 x 7.5 x 5.0 cm thoracoscopic left lower lobectomy showed a focally ulcerated fistulous tract that entered a 1.9 cm in diameter cyst that connected to a basilar-medial segmental bronchus. The passage was lined by stratified squamous epithelium, continuous with columnar ciliated epithelium, and was surrounded by intense chronic inflammation. The fistulous lumen contained partially degraded vegetable matter.
Diagnosing BEF can be clinically challenging. Symptoms are often intermittent, alternating between digestive and pulmonary in nature. Often, cough, gastroesophageal reflux, pneumonia, and bronchopulmonary suppuration can lead to medical management that is only masking, not definitively treating the underlying pathology. While tracheoesophageal fistulas are relatively common in presentation, and usually diagnosed in the newborn period, BEFs are rare and with varied clinical expression, which may explain delayed diagnosis.
Conclusion
BEF is a rare anomaly that may manifest ambiguous symptoms, thus delaying the diagnosis and options for earlier, less invasive curative interventions.
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Affiliation(s)
- S A Anderson
- Pathology, University of South Alabama, Mobile, Alabama, UNITED STATES
| | - S Liu
- Pathology, University of South Alabama, Mobile, Alabama, UNITED STATES
| | - C Galliani
- Pathology, University of South Alabama, Mobile, Alabama, UNITED STATES
| | - K Weaver
- Surgery, University of South Alabama, Mobile, Alabama, UNITED STATES
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Sameeta F, Anderson SA, Manci E, Haque M. Pediatric Pancreatic Teratoma: A Rare Case Report. Am J Clin Pathol 2020. [DOI: 10.1093/ajcp/aqaa161.098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Introduction/Objective
Teratomas are germ cell neoplasms arising from three germinal layers. They are classified as mature or immature. Mature cystic teratomas (MCTs), also known as dermoid cysts, are benign lesions. Common locations include the sacrococcygeal region, ovaries, testes, brain, mediastinumand retroperitoneum. MCT is extraordinarily rare in the pediatric pancreas; only 11 such cases have been reported in the English literature.
Methods
This eleven-month-old female presented for evaluation of two cystic masses in the body and tail of the pancreas. These masses were initially imaged as anechoic cysts in utero by ultrasound at 19 weeks gestational age and followed carefully over the interval. Her past medical history included a left upper lobectomy for congenital lobar emphysema. The pancreatic cysts were excised by laparoscopy.
Results
Grossly, the two tan-pink cysts measured 2.5 cm and 3.1 cm in greatest dimensions, had smooth inner linings and contained clear fluid. Microscopically, the cyst linings included low cuboidal, columnar, ciliated pseudostratified columnar respiratory or fundal gastric epithelia with underlying serous/mucous glands and smooth muscle. These findings were diagnosed as MCT.
Typically, MCT of pancreas have nonspecific clinical presentations, serum markers and imaging; all depending on the tissue types present; so, the diagnosis is primarily made postoperatively by pathological evaluation. Previously reported cases presented as single cysts, ranged 4 months to 16 years in age and measured 8 to 18 cm in greatest dimension. Complete surgical excision and careful follow-upare the mainstay of therapy
Conclusion
Pediatric pancreatic MCTs are extraordinarily rare, so the preoperative diagnosis and treatment is difficult. This case of MCT is the first reported multicystic presentation, the first documented fetal imaging and the smallest size in the English literature. This report shows that MCT must be considered in the differential diagnoses of fetal abdominal cysts and in multicystic pediatric pancreatic masses.
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Affiliation(s)
- F Sameeta
- Pathology, University of South Alabama, Mobile, Alabama, UNITED STATES
| | - S A Anderson
- Pathology, University of South Alabama, Mobile, Alabama, UNITED STATES
| | - E Manci
- Pathology, University of South Alabama, Mobile, Alabama, UNITED STATES
| | - M Haque
- Pathology, University of South Alabama, Mobile, Alabama, UNITED STATES
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7
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Anderson SA, Dal Zotto V. Tactile Corpuscle-like Bodies in Rectal Mucosa - A Mysterious Misleading Lesion. Am J Clin Pathol 2020. [DOI: 10.1093/ajcp/aqaa161.185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Introduction/Objective
Tactile corpuscle-like bodies (TCLB) are specialized mechanoreceptors derived from Schwannian structures, resembling Wagner-Meissner corpuscles which are often found in the skin and within schwannomas, neurofibromas, and melanocytic nevi. However, their presence in gastrointestinal mucosa is a rare phenomenon. To our knowledge, only 27 cases have been reported in the English literature.
Methods
We present two cases showing this rare entity in rectal mucosa. The first case is in a 34-year-old female was a past medical history significant for Ehlers-Danlos syndrome. The second case was submitted in consultation, of a 64-year-old male. In both cases, rectal polyps were identified on endoscopy.
Results
Histologically, clusters of unencapsulated, lamellated spindle cells in the lamina propria were identified. Immunoperoxidase stains using antibodies against CD68 and S100 protein were performed on both specimens. Additionally, on the first case synaptophysin was also performed. The laminated clusters were strongly positive for S100 and negative for CD68. The first case showed focally positive synatophysin. Although the etiology of TCLBs is still unclear, they are considered to be benign, incidental neural proliferations. The histological differential diagnosis includes: schwann cell hamartomas, neurofibromas, ganglioneuromas, mucosal neuromas, nodular amyloid deposition, or granulomas. However, those in question can be differentiated with the use of S100 protein and histiocytic markers.
Conclusion
Awareness of TCLBs is important. Although they are benign neural proliferations, it is important to differentiate from histologic mimics often associated with inherited syndromes.
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Affiliation(s)
- S A Anderson
- Pathology, University of South Alabama, Mobile, Alabama, UNITED STATES
| | - V Dal Zotto
- Pathology, University of South Alabama, Mobile, Alabama, UNITED STATES
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8
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Donegan JJ, Tyson JA, Branch SY, Beckstead MJ, Anderson SA, Lodge DJ. Stem cell-derived interneuron transplants as a treatment for schizophrenia: preclinical validation in a rodent model. Mol Psychiatry 2017; 22:1492-1501. [PMID: 27480492 PMCID: PMC5290293 DOI: 10.1038/mp.2016.121] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Revised: 06/17/2016] [Accepted: 06/21/2016] [Indexed: 01/28/2023]
Abstract
An increasing literature suggests that schizophrenia is associated with a reduction in hippocampal interneuron function. Thus, we posit that stem cell-derived interneuron transplants may be an effective therapeutic strategy to reduce hippocampal hyperactivity and attenuate behavioral deficits in schizophrenia. Here we used a dual-reporter embryonic stem cell line to generate enriched populations of parvalbumin (PV)- or somatostatin (SST)-positive interneurons, which were transplanted into the ventral hippocampus of the methylazoxymethanol rodent model of schizophrenia. These interneuron transplants integrate within the existing circuitry, reduce hippocampal hyperactivity and normalize aberrant dopamine neuron activity. Further, interneuron transplants alleviate behaviors that model negative and cognitive symptoms, including deficits in social interaction and cognitive inflexibility. Interestingly, PV- and SST-enriched transplants produced differential effects on behavior, with PV-enriched populations effectively normalizing all the behaviors examined. These data suggest that the stem cell-derived interneuron transplants may represent a novel therapeutic strategy for schizophrenia.
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Affiliation(s)
- J J Donegan
- Department of Pharmacology and Center for Biomedical Neuroscience, University of Texas Health Science Center, San Antonio, TX, USA
| | - J A Tyson
- Department of Psychiatry, Children's Hospital of Philadelphia, University of Pennsylvania School of Medicine, Philadelphia, PA, USA
| | - S Y Branch
- Department of Physiology and Center for Biomedical Neuroscience, University of Texas Health Science Center, San Antonio, TX, USA
| | - M J Beckstead
- Department of Physiology and Center for Biomedical Neuroscience, University of Texas Health Science Center, San Antonio, TX, USA
| | - S A Anderson
- Department of Psychiatry, Children's Hospital of Philadelphia, University of Pennsylvania School of Medicine, Philadelphia, PA, USA
| | - D J Lodge
- Department of Pharmacology and Center for Biomedical Neuroscience, University of Texas Health Science Center, San Antonio, TX, USA
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9
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Yang H, Anderson SA, Forshee R, Williams A, Epstein JS, Marks PW. Modeling complete removal of risk assessment questions in the USA predicts the risk of HIV exposure in blood recipients could increase despite the use of nucleic acid testing. Vox Sang 2016; 110:324-8. [PMID: 26765975 DOI: 10.1111/vox.12375] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [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: 09/25/2015] [Revised: 12/07/2015] [Accepted: 12/08/2015] [Indexed: 11/28/2022]
Abstract
BACKGROUND AND OBJECTIVES The safety of the blood supply in a number of countries is achieved by interventions that include behaviour-based time-limited or indefinite deferrals and screening of donated units for transfusion-transmitted infections. The relatively high sensitivity of nucleic acid testing (NAT) used in blood donor screening has raised the question of whether such time-based deferrals can be eliminated in favour of individual risk assessment. MATERIALS AND METHODS Data on the annual number of incident human immunodeficiency virus (HIV) infections associated with various behaviours and on the performance characteristics of NAT applied to donor screening were used to model the number of potentially infected units that might escape detection in the worst-case scenario in which individual risk assessment was implemented, but was not effective as a screening tool, and donors did not otherwise self-select for lower risk. RESULTS In the absence of effective individual risk-based screening or donor self-selection, the model predicts that in the United States, an additional 39 (95% CI 35-43) HIV-infected units would escape detection by nucleic acid testing, potentially capable of exposing approximately 68 (95% CI 61-75) individuals to the risk of HIV infection through the administration of prepared blood components. CONCLUSION Despite some inherent uncertainty, the worst-case scenario of completely ineffective individual risk assessment, absence of donor self-selection and increased reliance on NAT for blood screening is estimated to be associated with an approximately fourfold increase in the risk of HIV exposure through transfusion in the United States.
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Affiliation(s)
- H Yang
- Center for Biologics Evaluation and Research, US Food and Drug Administration, Silver Spring, MD, USA
| | - S A Anderson
- Center for Biologics Evaluation and Research, US Food and Drug Administration, Silver Spring, MD, USA
| | - R Forshee
- Center for Biologics Evaluation and Research, US Food and Drug Administration, Silver Spring, MD, USA
| | - A Williams
- Center for Biologics Evaluation and Research, US Food and Drug Administration, Silver Spring, MD, USA
| | - J S Epstein
- Center for Biologics Evaluation and Research, US Food and Drug Administration, Silver Spring, MD, USA
| | - P W Marks
- Center for Biologics Evaluation and Research, US Food and Drug Administration, Silver Spring, MD, USA
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10
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Ball R, Robb M, Anderson SA, Dal Pan G. The FDA's sentinel initiative-A comprehensive approach to medical product surveillance. Clin Pharmacol Ther 2016; 99:265-8. [DOI: 10.1002/cpt.320] [Citation(s) in RCA: 150] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Revised: 11/30/2015] [Accepted: 12/08/2015] [Indexed: 11/10/2022]
Affiliation(s)
- R Ball
- Center for Drug Evaluation and Research, Food and Drug Administration; Silver Spring Maryland USA
| | - M Robb
- Center for Drug Evaluation and Research, Food and Drug Administration; Silver Spring Maryland USA
| | - SA Anderson
- Center for Biologics Evaluation and Research, Food and Drug Administration; Silver Spring Maryland USA
| | - G Dal Pan
- Center for Drug Evaluation and Research, Food and Drug Administration; Silver Spring Maryland USA
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Ekezue BF, Sridhar G, Ovanesov MV, Forshee RA, Izurieta HS, Selvam N, Parunov LA, Jain N, Mintz PD, Epstein JS, Anderson SA, Menis MD. Clotting factor product administration and same-day occurrence of thrombotic events, as recorded in a large healthcare database during 2008-2013. J Thromb Haemost 2015; 13:2168-79. [PMID: 26414338 DOI: 10.1111/jth.13155] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Accepted: 09/12/2015] [Indexed: 11/30/2022]
Abstract
BACKGROUND Thrombotic events (TEs) are serious adverse events that can occur following administration of clotting factors (CFs). OBJECTIVES To evaluate occurrence of same-day TEs for different CF products and potential risk factors. METHODS A retrospective cohort study of individuals exposed to CF products during 2008-2013 was conducted using a large commercial insurance database. CF products were identified by procedure codes, and TEs were ascertained via diagnosis codes. Crude same-day TE rates (per 1000 persons exposed) were estimated overall and by congenital factor deficiency (CFD) status, CF products, age and gender. Multivariable logistic regression analyses were used to control for confounding. Laboratory analysis was used to compare the procoagulant activities of FIX products. RESULTS Of 3801 individuals exposed to CFs, 117 (30.8 per 1000) had same-day TEs recorded. The crude same-day TE rate was higher for CF users without CFD, 70.2 (102 of 1452), as compared with those with CFD, 6.4 (15 of 2349) (RR, 11.0; 95% CI, 6.4-18.9). For individuals without CFD, a significantly increased same-day TE risk was identified for factor IX complex (OR, 6.92; 95% CI, 3.11-15.40), factor VIIa (OR, 9.42; 95% CI, 4.99-17.78) and other products when compared with fibrin sealant. An increased risk of a TE was found with older age (≥ 45 years), history of TEs and underlying health conditions. The laboratory identified elevated procoagulant activity in Profilnine(®) and Benefix(®) . CONCLUSIONS The study shows an increased same-day TE risk for CF users without CFD and suggests substantial off-label CF use. The study findings also show elevated same-day TE rates for different CF products and suggest the importance of product properties and patient factors.
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Affiliation(s)
| | - G Sridhar
- HealthCore Inc, Silver Spring, MD, USA
| | - M V Ovanesov
- Center for Biologics Evaluation and Research, US Food and Drug Administration, Silver Spring, MD, USA
| | - R A Forshee
- Center for Biologics Evaluation and Research, US Food and Drug Administration, Silver Spring, MD, USA
| | - H S Izurieta
- Center for Biologics Evaluation and Research, US Food and Drug Administration, Silver Spring, MD, USA
| | - N Selvam
- HealthCore Inc, Silver Spring, MD, USA
| | - L A Parunov
- Center for Biologics Evaluation and Research, US Food and Drug Administration, Silver Spring, MD, USA
| | - N Jain
- Center for Biologics Evaluation and Research, US Food and Drug Administration, Silver Spring, MD, USA
| | - P D Mintz
- Center for Biologics Evaluation and Research, US Food and Drug Administration, Silver Spring, MD, USA
| | - J S Epstein
- Center for Biologics Evaluation and Research, US Food and Drug Administration, Silver Spring, MD, USA
| | - S A Anderson
- Center for Biologics Evaluation and Research, US Food and Drug Administration, Silver Spring, MD, USA
| | - M D Menis
- Center for Biologics Evaluation and Research, US Food and Drug Administration, Silver Spring, MD, USA
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12
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Zhao N, Nizzi CP, Anderson SA, Wang J, Ueno A, Tsukamoto H, Eisenstein RS, Enns CA, Zhang AS. Low intracellular iron increases the stability of matriptase-2. J Biol Chem 2014; 290:4432-46. [PMID: 25550162 DOI: 10.1074/jbc.m114.611913] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Matriptase-2 (MT2) is a type II transmembrane serine protease that is predominantly expressed in hepatocytes. It suppresses the expression of hepatic hepcidin, an iron regulatory hormone, by cleaving membrane hemojuvelin into an inactive form. Hemojuvelin is a bone morphogenetic protein (BMP) co-receptor. Here, we report that MT2 is up-regulated under iron deprivation. In HepG2 cells stably expressing the coding sequence of the MT2 gene, TMPRSS6, incubation with apo-transferrin or the membrane-impermeable iron chelator, deferoxamine mesylate salt, was able to increase MT2 levels. This increase did not result from the inhibition of MT2 shedding from the cells. Rather, studies using a membrane-permeable iron chelator, salicylaldehyde isonicotinoyl hydrazone, revealed that depletion of cellular iron was able to decrease the degradation of MT2 independently of internalization. We found that lack of the putative endocytosis motif in its cytoplasmic domain largely abolished the sensitivity of MT2 to iron depletion. Neither acute nor chronic iron deficiency was able to alter the association of Tmprss6 mRNA with polyribosomes in the liver of rats indicating a lack of translational regulation by low iron levels. Studies in mice showed that Tmprss6 mRNA was not regulated by iron nor the BMP-mediated signaling with no evident correlation with either Bmp6 mRNA or Id1 mRNA, a target of BMP signaling. These results suggest that regulation of MT2 occurs at the level of protein degradation rather than by changes in the rate of internalization and translational or transcriptional mechanisms and that the cytoplasmic domain of MT2 is necessary for its regulation.
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Affiliation(s)
- Ningning Zhao
- From the Department of Cell and Developmental Biology, Oregon Health and Science University, Portland, Oregon 97239
| | - Christopher P Nizzi
- the Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, Wisconsin 53706
| | - Sheila A Anderson
- the Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, Wisconsin 53706
| | - Jiaohong Wang
- the Department of Pathology, Keck School of Medicine, University of Southern California, Los Angeles, California 90033, and
| | - Akiko Ueno
- the Department of Pathology, Keck School of Medicine, University of Southern California, Los Angeles, California 90033, and
| | - Hidekazu Tsukamoto
- the Department of Pathology, Keck School of Medicine, University of Southern California, Los Angeles, California 90033, and the Department of Veteran Affairs, Greater Los Angeles Healthcare System, Los Angeles, California 90073
| | - Richard S Eisenstein
- the Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, Wisconsin 53706
| | - Caroline A Enns
- From the Department of Cell and Developmental Biology, Oregon Health and Science University, Portland, Oregon 97239
| | - An-Sheng Zhang
- From the Department of Cell and Developmental Biology, Oregon Health and Science University, Portland, Oregon 97239,
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13
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Ekezue BF, Sridhar G, Izurieta HS, Forshee RA, Selvam N, Ovanesov MV, Jain N, Mintz PD, Anderson SA, Menis M. Clotting Factor (Cf) Product Use And Same-Day Risk For Thrombotic Adverse Events (Tes), As Recorded In Large Health Care Database During 2008-2013 Study Period. Value Health 2014; 17:A473. [PMID: 27201359 DOI: 10.1016/j.jval.2014.08.1348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Affiliation(s)
| | - G Sridhar
- HealthCore Inc., Alexandria, VA, USA
| | - H S Izurieta
- U. S. Federal Drug Administration, Silver Spring, MD, USA
| | - R A Forshee
- U. S. Federal Drug Administration, Silver Spring, MD, USA
| | - N Selvam
- HealthCore Inc., Alexandria, VA, USA
| | - M V Ovanesov
- U. S. Federal Drug Administration, Silver Spring, MD, USA
| | - N Jain
- U. S. Federal Drug Administration, Silver Spring, MD, USA
| | - P D Mintz
- U. S. Federal Drug Administration, Silver Spring, MD, USA
| | - S A Anderson
- U. S. Federal Drug Administration, Silver Spring, MD, USA
| | - M Menis
- U. S. Federal Drug Administration, Silver Spring, MD, USA
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14
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Chung J, Anderson SA, Gwynn B, Deck KM, Chen MJ, Langer NB, Shaw GC, Huston NC, Boyer LF, Datta S, Paradkar PN, Li L, Wei Z, Lambert AJ, Sahr K, Wittig JG, Chen W, Lu W, Galy B, Schlaeger TM, Hentze MW, Ward DM, Kaplan J, Eisenstein RS, Peters LL, Paw BH. Iron regulatory protein-1 protects against mitoferrin-1-deficient porphyria. J Biol Chem 2014. [DOI: 10.1074/jbc.a114.547778] [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: 11/06/2022] Open
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15
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Chung J, Anderson SA, Gwynn B, Deck KM, Chen MJ, Langer NB, Shaw GC, Huston NC, Boyer LF, Datta S, Paradkar PN, Li L, Wei Z, Lambert AJ, Sahr K, Wittig JG, Chen W, Lu W, Galy B, Schlaeger TM, Hentze MW, Ward DM, Kaplan J, Eisenstein RS, Peters LL, Paw BH. Iron regulatory protein-1 protects against mitoferrin-1-deficient porphyria. J Biol Chem 2014; 289:7835-43. [PMID: 24509859 DOI: 10.1074/jbc.m114.547778] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Mitochondrial iron is essential for the biosynthesis of heme and iron-sulfur ([Fe-S]) clusters in mammalian cells. In developing erythrocytes, iron is imported into the mitochondria by MFRN1 (mitoferrin-1, SLC25A37). Although loss of MFRN1 in zebrafish and mice leads to profound anemia, mutant animals showed no overt signs of porphyria, suggesting that mitochondrial iron deficiency does not result in an accumulation of protoporphyrins. Here, we developed a gene trap model to provide in vitro and in vivo evidence that iron regulatory protein-1 (IRP1) inhibits protoporphyrin accumulation. Mfrn1(+/gt);Irp1(-/-) erythroid cells exhibit a significant increase in protoporphyrin levels. IRP1 attenuates protoporphyrin biosynthesis by binding to the 5'-iron response element (IRE) of alas2 mRNA, inhibiting its translation. Ectopic expression of alas2 harboring a mutant IRE, preventing IRP1 binding, in Mfrn1(gt/gt) cells mimics Irp1 deficiency. Together, our data support a model whereby impaired mitochondrial [Fe-S] cluster biogenesis in Mfrn1(gt/gt) cells results in elevated IRP1 RNA-binding that attenuates ALAS2 mRNA translation and protoporphyrin accumulation.
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Affiliation(s)
- Jacky Chung
- From the Division of Hematology, Brigham and Women's Hospital; Division of Hematology-Oncology, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts 02115
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16
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Ruiz JC, Walker SD, Anderson SA, Eisenstein RS, Bruick RK. F-box and leucine-rich repeat protein 5 (FBXL5) is required for maintenance of cellular and systemic iron homeostasis. J Biol Chem 2012; 288:552-60. [PMID: 23135277 PMCID: PMC3537052 DOI: 10.1074/jbc.m112.426171] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [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] [Indexed: 01/20/2023] Open
Abstract
Maintenance of cellular iron homeostasis requires post-transcriptional regulation of iron metabolism genes by iron regulatory protein 2 (IRP2). The hemerythrin-like domain of F-box and leucine-rich repeat protein 5 (FBXL5), an E3 ubiquitin ligase subunit, senses iron and oxygen availability and facilitates IRP2 degradation in iron replete cells. Disruption of the ubiquitously expressed murine Fbxl5 gene results in a failure to sense increased cellular iron availability, accompanied by constitutive IRP2 accumulation and misexpression of IRP2 target genes. FBXL5-null mice die during embryogenesis, although viability is restored by simultaneous deletion of the IRP2, but not IRP1, gene. Mice containing a single functional Fbxl5 allele behave like their wild type littermates when fed an iron-sufficient diet. However, unlike wild type mice that manifest decreased hematocrit and hemoglobin levels when fed a low-iron diet, Fbxl5 heterozygotes maintain normal hematologic values due to increased iron absorption. The responsiveness of IRP2 to low iron is specifically enhanced in the duodena of the heterozygotes and is accompanied by increased expression of the divalent metal transporter-1. These results confirm the role of FBXL5 in the in vivo maintenance of cellular and systemic iron homeostasis and reveal a privileged role for the intestine in their regulation by virtue of its unique FBXL5 iron sensitivity.
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Affiliation(s)
- Julio C Ruiz
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9038, USA
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17
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Tiwari JL, Schneider B, Barton F, Anderson SA. Islet cell transplantation in type 1 diabetes: an analysis of efficacy outcomes and considerations for trial designs. Am J Transplant 2012; 12:1898-907. [PMID: 22486926 DOI: 10.1111/j.1600-6143.2012.04038.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
To estimate treatment effect size and other parameters required for planning the designs and analyses of future phase 3 islet transplant trials, we analyzed key clinical and laboratory outcomes of 347 allogeneic islet transplant recipients, using data from the Collaborative Islet Transplant Registry (CITR). At 1 year, approximately 59% of all transplant recipients were free of severe hypoglycemic events and maintained hemoglobin A1c (HbA1c) level of ≤ 6.5%. The Kaplan-Meier (KM) survival analyses showed that 69%, 54% and 44% of these 1-year responders maintained this composite endpoint at 2, 3 and 4 years, respectively. Ninety-one percent of all recipients were free of severe hypoglycemic episodes at 1 year. Furthermore, the KM survival estimates showed that 91%, 85% and 80% of these subjects maintained this clinical benefit at 2, 3 and 4 years, respectively. These results can be very useful in developing framework for study designs, sample size estimates, and statistical analysis plans for future pivotal trials of islet cell transplantation in type 1 diabetes.
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Affiliation(s)
- J L Tiwari
- Office of Biostatistics and Epidemiology, Center for Biologics Evaluation and Research, Food and Drug Administration, Rockville, MD, USA.
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18
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Anderson SA, Salinas I, Walker SP, Gublin Y, Pether S, Kohn YY, Symonds JE. Early development of New Zealand hapuku Polyprion oxygeneios eggs and larvae. J Fish Biol 2012; 80:555-571. [PMID: 22380553 DOI: 10.1111/j.1095-8649.2011.03191.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
This study describes for the first time the normal development of New Zealand hapuku Polyprion oxygeneios embryos and larvae reared from fertilization to 11 days post-hatch (dph) at a constant temperature. Fertilized eggs were obtained from natural spawnings from communally reared captive wild broodstock. Eggs averaged 2 mm in diameter and had single or multiple oil globules. Embryos developed following the main fish embryological stages and required an average of 1859·50 degree hours post-fertilization (dhpf) to hatch. The newly hatched larvae (4·86 mm mean total length, L(T) ) were undifferentiated, with unpigmented eyes, a single and simple alimentary tube and a finfold that covered the entire body. Larvae relied on the energy from the yolk-sac reserves until 11 dph (7·33 mm mean L(T) ), when yolk-sac reabsorption was almost completed. Some of the major developmental stages from hatching to yolk-sac reabsorption were eye pigmentation (5 dph), upper jaw formation (7 dph), lower jaw formation (8 dph) and mouth opening (8-9 dph). By 9 dph, the digestive system consisted of pancreas, liver, primordial stomach, anterior and posterior gut; therefore, P. oxygeneios larvae would be capable of feeding on live prey. The developmental, morphological and histological data described constitutes essential baseline information on P. oxygeneios biology and normal development.
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Affiliation(s)
- S A Anderson
- National Institute of Water and Atmospheric Research Ltd, Private Bag 14-901, Wellington 6241, New Zealand
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19
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Zhang A, Anderson SA, Wang J, Yang F, DeMaster K, Eisenstein RS, Tsukamoto H, Enns CA. Suppression of hepatic hepcidin expression in response to acute iron deficiency is correlated with an increase of matripatase‐2 protein in the liver. FASEB J 2010. [DOI: 10.1096/fasebj.24.1_supplement.1011.2] [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: 11/11/2022]
Affiliation(s)
- An‐Sheng Zhang
- Department of Cell & Developmental BiologyOHSUPortlandOR
| | - Sheila A Anderson
- Department of Nutritional SciencesUniversity of Wisconsin‐MadisonMadisonWI
| | - Jiaohong Wang
- Department of PathologyUniversity of Southern CaliforniaLos AngelesCA
| | - Fan Yang
- Division of BiologyCalifornia Institute of TechnologyLos AngelesCA
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20
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Goforth JB, Anderson SA, Nizzi CP, Eisenstein RS. Multiple determinants within iron-responsive elements dictate iron regulatory protein binding and regulatory hierarchy. RNA 2010; 16:154-69. [PMID: 19939970 PMCID: PMC2802025 DOI: 10.1261/rna.1857210] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [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] [Indexed: 05/16/2023]
Abstract
Iron regulatory proteins (IRPs) are iron-regulated RNA binding proteins that, along with iron-responsive elements (IREs), control the translation of a diverse set of mRNA with 5' IRE. Dysregulation of IRP action causes disease with etiology that may reflect differential control of IRE-containing mRNA. IREs are defined by a conserved stem-loop structure including a midstem bulge at C8 and a terminal CAGUGH sequence that forms an AGU pseudo-triloop and N19 bulge. C8 and the pseudo-triloop nucleotides make the majority of the 22 identified bonds with IRP1. We show that IRP1 binds 5' IREs in a hierarchy extending over a ninefold range of affinities that encompasses changes in IRE binding affinity observed with human L-ferritin IRE mutants. The limits of this IRE binding hierarchy are predicted to arise due to small differences in binding energy (e.g., equivalent to one H-bond). We demonstrate that multiple regions of the IRE stem not predicted to contact IRP1 help establish the binding hierarchy with the sequence and structure of the C8 region displaying a major role. In contrast, base-pairing and stacking in the upper stem region proximal to the terminal loop had a minor role. Unexpectedly, an N20 bulge compensated for the lack of an N19 bulge, suggesting the existence of novel IREs. Taken together, we suggest that a regulatory binding hierarchy is established through the impact of the IRE stem on the strength, not the number, of bonds between C8 or pseudo-triloop nucleotides and IRP1 or through their impact on an induced fit mechanism of binding.
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Affiliation(s)
- Jeremy B Goforth
- Department of Nutritional Sciences, University of Wisconsin, Madison, Wisconsin 53706, USA
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21
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Smith PJ, McVeagh SM, Hulston D, Anderson SA, Gublin Y. DNA identification of ciliates associated with disease outbreaks in a New Zealand marine fish hatchery. Dis Aquat Organ 2009; 86:163-167. [PMID: 19902845 DOI: 10.3354/dao02113] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Ciliates associated with fish mortalities in a New Zealand hatchery were identified by DNA sequencing of the small subunit ribosomal RNA gene (SSU rRNA). Tissue samples were taken from lesions and gill tissues on freshly dead juvenile groper, brain tissue from adult kingfish, and from ciliate cultures and rotifers derived from fish mortality events between January 2007 and March 2009. Different mortality events were characterized by either of 2 ciliate species, Uronema marinum and Miamiensis avidus. A third ciliate, Mesanophrys carcini, was identified in rotifers used as food for fish larvae. Sequencing part of the SSU rRNA provided a rapid tool for the identification and monitoring of scuticociliates in the hatchery and allowed the first identification of these species in farmed fish in New Zealand.
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Affiliation(s)
- P J Smith
- National Institute of Water and Atmospheric Research (NIWA), Private Bag 14901, Wellington, New Zealand.
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22
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Deck KM, Vasanthakumar A, Anderson SA, Goforth JB, Kennedy MC, Antholine WE, Eisenstein RS. Evidence that phosphorylation of iron regulatory protein 1 at Serine 138 destabilizes the [4Fe-4S] cluster in cytosolic aconitase by enhancing 4Fe-3Fe cycling. J Biol Chem 2009; 284:12701-9. [PMID: 19269970 DOI: 10.1074/jbc.m807717200] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Iron-sulfur cluster-dependent interconversion of iron regulatory protein 1 (IRP1) between its RNA binding and cytosolic aconitase (c-acon) forms controls vertebrate iron homeostasis. Cluster removal from c-acon is thought to include oxidative demetallation as a required step, but little else is understood about the process of conversion to IRP1. In comparison with c-acon(WT), Ser(138) phosphomimetic mutants of c-acon contain an unstable [4Fe-4S] cluster and were used as tools to further define the pathway(s) of iron-sulfur cluster disassembly. Under anaerobic conditions cluster insertion into purified IRP1(S138E) and cluster loss on treatment with NO regulated aconitase and RNA binding activity over a similar range as observed for IRP1(WT). However, activation of RNA binding of c-acon(S138E) was an order of magnitude more sensitive to NO than for c-acon(WT). Consistent with this, an altered set point between RNA-binding and aconitase forms was observed for IRP1(S138E) when expressed in HEK cells. Active c-acon(S138E) could only accumulate under hypoxic conditions, suggesting enhanced cluster disassembly in normoxia. Cluster disassembly mechanisms were further probed by determining the impact of iron chelation on acon activity. Unexpectedly EDTA rapidly inhibited c-acon(S138E) activity without affecting c-acon(WT). Additional chelator experiments suggested that cluster loss can be initiated in c-acon(S138E) through a spontaneous nonoxidative demetallation process. Taken together, our results support a model wherein Ser(138) phosphorylation sensitizes IRP1/c-acon to decreased iron availability by allowing the [4Fe-4S](2+) cluster to cycle with [3Fe-4S](0) in the absence of cluster perturbants, indicating that regulation can be initiated merely by changes in iron availability.
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Affiliation(s)
- Kathryn M Deck
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, WI 53706, USA
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23
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Zhang AS, Anderson SA, Meyers KR, Hernandez C, Eisenstein RS, Enns CA. Evidence that inhibition of hemojuvelin shedding in response to iron is mediated through neogenin. J Biol Chem 2007; 282:12547-56. [PMID: 17331953 DOI: 10.1074/jbc.m608788200] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.2] [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
Hemojuvelin (HJV), encoded by the gene HFE2, is a critical upstream regulator of hepcidin expression. Hepcidin, the central iron regulatory hormone, is secreted from hepatocytes, whereas HFE2 is highly expressed in skeletal muscle and liver. Previous studies demonstrated that HJV is a GPI-anchored protein, binds the proteins neogenin and bone morphogenetic proteins (BMP2 and BMP4), and can be released from the cell membrane (shedding). In this study, we investigated the physiological significance and the underlying mechanism of HJV shedding. In acutely iron-deficient rats with markedly suppressed hepatic hepcidin expression, we detected an early phase increase of serum HJV with no significant change of either HFE2 mRNA or protein levels in gastrocnemius muscle. Studies in both C2C12 (a mouse myoblast cell line) and HepG2 (a human hepatoma cell line) cells showed active HJV shedding, implying that both skeletal muscle and liver could be the source of serum HJV. In agreement with the observations in iron-deficient rats, HJV shedding in these cell lines was down-regulated by holo-transferrin in a concentration-dependent manner. Our present study showing that knock-down of endogenous neogenin, a HJV receptor, in C2C12 cells suppresses HJV shedding and that overexpression of neogenin in HEK293 cells markedly enhances this process, suggests that membrane HJV shedding is mediated by neogenin. The finding that neither BMP4 nor its antagonist, noggin, was able to alter HJV shedding support the lack of involvement of BMP signaling pathway in this process.
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Affiliation(s)
- An-Sheng Zhang
- Department of Cell and Developmental Biology, Oregon Health & Science University, Portland, Oregon 97239, USA.
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24
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Sissons CH, Anderson SA, Wong L, Coleman MJ, White DC. Microbiota of plaque microcosm biofilms: effect of three times daily sucrose pulses in different simulated oral environments. Caries Res 2007; 41:413-22. [PMID: 17713343 DOI: 10.1159/000104801] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2006] [Accepted: 12/01/2006] [Indexed: 11/19/2022] Open
Abstract
AIM To explore the Ecological Plaque Hypothesis for dental caries. To test modification of the microbiota of dental plaque microcosm biofilms by sucrose pulsing during growth in two different simulated oral fluids, and with a urea-induced plaque pH elevation. METHODS Plaque microcosm biofilms were cultured in an 'artificial mouth' with and without 6-min 5% w/v sucrose pulses every 8 h in an environment of continuously supplied saliva-like defined medium with mucin (DMM), or basal medium mucin (BMM, a high-peptone-yeast extract oral fluid analogue), and also in DMM + 10 mmol/l urea, with sucrose pulsing. Forty plaque species were quantified by checkerboard DNA:DNA hybridization analysis. RESULTS Sucrose pulsing extended rapid plaque growth in DMM and BMM, inducing major microbiota changes in DMM but not in BMM. In DMM, some streptococci and lactobacilli were unaffected while others implicated in caries, together with Candida albicans and Capnocytophaga gingivalis, increased. Aerobic, microaerophilic and major anaerobic species decreased. Elevation of the pH(max) from 6.4 to 7.0 had almost no effect on the microbiota. BMM plaques were distinct from DMM plaques with particularly low levels of Candida albicans and Actinomyces. CONCLUSIONS Modest sucrose exposure in a saliva-like environment causes profound changes in the developmental self-organization of plaque microcosms, supporting the Ecological Plaque Hypothesis. Nevertheless, there is significant stability in microbial composition with varying pH near neutrality. Increases in levels of specific bacteria in response to sucrose could be characteristic of organisms particularly important in caries.
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Affiliation(s)
- C H Sissons
- Dental Research Group, Department of Pathology and Molecular Medicine, Wellington School of Medicine and Health Sciences, University of Otago, Wellington, New Zealand.
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25
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Boasso A, Hardy AW, Herbeuval JP, Anderson SA, Dolan MJ, Lifson JD, Fuchs D, Shearer GM. HIV activates indoleamine 2,3-dioxygenease: inhibition of T cell proliferation by tryptophan starvation. Retrovirology 2006. [PMCID: PMC1716829 DOI: 10.1186/1742-4690-3-s1-p11] [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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26
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Pondarré C, Antiochos BB, Campagna DR, Clarke SL, Greer EL, Deck KM, McDonald A, Han AP, Medlock A, Kutok JL, Anderson SA, Eisenstein RS, Fleming MD. The mitochondrial ATP-binding cassette transporter Abcb7 is essential in mice and participates in cytosolic iron–sulfur cluster biogenesis. Hum Mol Genet 2006; 15:953-64. [PMID: 16467350 DOI: 10.1093/hmg/ddl012] [Citation(s) in RCA: 162] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Proteins with iron-sulfur (Fe-S) clusters participate in multiple metabolic pathways throughout the cell. The mitochondrial ABC half-transporter Abcb7, which is mutated in X-linked sideroblastic anemia with ataxia in humans, is a functional ortholog of yeast Atm1p and is predicted to export a mitochondrially derived metabolite required for cytosolic Fe-S cluster assembly. Using an inducible Cre/loxP system to delete exons 9 and 10 of the Abcb7 gene, we examined the phenotype of mice deficient in Abcb7. We found that Abcb7 was essential in extra-embryonic tissues early in gestation and that the mutant allele exhibits an X-linked parent-of-origin lethality effect. Furthermore, using X-chromosome inactivation assays and tissue-specific deletions, Abcb7 was found to be essential for the development and function of numerous other cell types and tissues. A notable exception to this was liver, where loss of Abcb7 impaired cytosolic Fe-S cluster assembly but was not lethal. In this situation, control of iron regulatory protein 1, a key cytosolic modulator of iron metabolism, which is responsive to the availability of cytosolic Fe-S clusters, was impaired and contributed to the dysregulation of hepatocyte iron metabolism. Altogether, these studies demonstrate the essential nature of Abcb7 in mammals and further substantiate a central role for mitochondria in the biogenesis of cytosolic Fe-S proteins.
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Affiliation(s)
- Corinne Pondarré
- Department of Pathology, Children's Hospital and Harvard Medical School, Boston, MA 02115, USA
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27
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Clarke SL, Vasanthakumar A, Anderson SA, Pondarré C, Koh CM, Deck KM, Pitula JS, Epstein CJ, Fleming MD, Eisenstein RS. Iron-responsive degradation of iron-regulatory protein 1 does not require the Fe-S cluster. EMBO J 2006; 25:544-53. [PMID: 16424901 PMCID: PMC1383537 DOI: 10.1038/sj.emboj.7600954] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2005] [Accepted: 12/19/2005] [Indexed: 11/08/2022] Open
Abstract
The generally accepted role of iron-regulatory protein 1 (IRP1) in orchestrating the fate of iron-regulated mRNAs depends on the interconversion of its cytosolic aconitase and RNA-binding forms through assembly/disassembly of its Fe-S cluster, without altering protein abundance. Here, we show that IRP1 protein abundance can be iron-regulated. Modulation of IRP1 abundance by iron did not require assembly of the Fe-S cluster, since a mutant with all cluster-ligating cysteines mutated to serine underwent iron-induced protein degradation. Phosphorylation of IRP1 at S138 favored the RNA-binding form and promoted iron-dependent degradation. However, phosphorylation at S138 was not required for degradation. Further, degradation of an S138 phosphomimetic mutant was not blocked by mutation of cluster-ligating cysteines. These findings were confirmed in mouse models with genetic defects in cytosolic Fe-S cluster assembly/disassembly. IRP1 RNA-binding activity was primarily regulated by IRP1 degradation in these animals. Our results reveal a mechanism for regulating IRP1 action relevant to the control of iron homeostasis during cell proliferation, inflammation, and in response to diseases altering cytosolic Fe-S cluster assembly or disassembly.
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Affiliation(s)
- Stephen L Clarke
- Department of Nutritional Sciences, University of Wisconsin, Madison, WI, USA
| | | | - Sheila A Anderson
- Department of Nutritional Sciences, University of Wisconsin, Madison, WI, USA
| | - Corinne Pondarré
- Department of Pathology, Children's Hospital and Harvard Medical School, Boston, MA, USA
| | - Cheryl M Koh
- Department of Nutritional Sciences, University of Wisconsin, Madison, WI, USA
| | - Kathryn M Deck
- Department of Nutritional Sciences, University of Wisconsin, Madison, WI, USA
| | - Joseph S Pitula
- Department of Nutritional Sciences, University of Wisconsin, Madison, WI, USA
| | - Charles J Epstein
- Department of Pediatrics and Center for Human Genetics, University of California, San Francisco, CA, USA
| | - Mark D Fleming
- Department of Pathology, Children's Hospital and Harvard Medical School, Boston, MA, USA
| | - Richard S Eisenstein
- Department of Nutritional Sciences, University of Wisconsin, Madison, WI, USA
- Department of Nutritional Sciences, University of Wisconsin-Madison, 1415 Linden Drive, Madison, WI 53706, USA. Tel.: +1 608 262 5830; Fax: +1 608 262 5860; E-mail:
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28
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Klein CJ, Wu Y, Kruckeberg KE, Hebbring SJ, Anderson SA, Cunningham JM, Dyck PJB, Klein DM, Thibodeau SN, Dyck PJ. SPTLC1 and RAB7 mutation analysis in dominantly inherited and idiopathic sensory neuropathies. J Neurol Neurosurg Psychiatry 2005; 76:1022-4. [PMID: 15965219 PMCID: PMC1739730 DOI: 10.1136/jnnp.2004.050062] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND The variable clinical features of hereditary sensory and autonomic neuropathy (HSAN I) suggest heterogeneity. Some cases of idiopathic sensory neuropathy could be caused by missense mutations of SPTLC1 and RAB7 and not be recognised as familial. OBJECTIVE To screen persons with dominantly inherited HSAN I and others with idiopathic sensory neuropathies for known mutations of SPTLC1 and RAB7. PATIENTS DNA was examined from well characterised individuals of 25 kindreds with adult onset HSAN I for mutations of SPTLC1 and RAB7; 92 patients with idiopathic sensory neuropathy were also screened for known mutations of these genes. RESULTS Of the 25 kindreds, only one had a mutation (SPTLC1 399T-->G). This kindred, and 10 without identified mutations, had prominent mutilating foot injuries with peroneal weakness. Of the remainder, 12 had foot insensitivity with injuries but no weakness, one had restless legs and burning feet, and one had dementia with hearing loss. No mutation of RAB7 was found in any of these. No known mutations of SPTLC1 or RAB7 were found in cases of idiopathic sensory neuropathy. CONCLUSIONS Adult onset HSAN I is clinically and genetically heterogeneous and further work is required to identify additional genetic causes. Known SPTLC1or RAB7 mutations were not found in idiopathic sensory neuropathy.
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Affiliation(s)
- C J Klein
- The Peripheral Neuropathy Research Laboratory, Mayo Clinic College of Medicine, Rochester, MN 55905, USA.
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29
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Frank JA, Anderson SA, Kalsih H, Jordan EK, Lewis BK, Yocum GT, Arbab AS. Methods for magnetically labeling stem and other cells for detection by in vivo magnetic resonance imaging. Cytotherapy 2004; 6:621-5. [PMID: 15773025 DOI: 10.1080/14653240410005267-1] [Citation(s) in RCA: 96] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Superparamagnetic iron oxide (SPIO) nanoparticles are being used for intracellular magnetic labeling of stem cells and other cells in order to monitor cell trafficking by magnetic resonance imaging (MRI) as part of cellular-based repair, replacement and treatment strategies. This review focuses on the various methods for magnetic labeling of stem cells and other mammalian cells and on how to translate experimental results from bench to bedside.
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Affiliation(s)
- J A Frank
- Experimental Neuroimaging Section, Laboratory of Diagnostic Radiology Research, Clinical Center, NIH, Bethesda, MD 20892-1074, USA
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30
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Abstract
The ability of oral bacteria to integrate within a biofilm is pivotal to their survival. A dependence on the amount of biofilm growth by noncoaggregating Lactobacillus rhamnosus and Lactobacillus plantarum on coculture with Actinomyces naeslundii, Actinomyces gerencseriae, Streptococcus mutans and Veillonella parvula was investigated using an artificial-mouth culture system. Biofilm formation by the lactobacilli in mono-culture was poor. In coculture with Actinomyces species the amount of L. rhamnosus increased 7-20 times and L. plantarum 4-7 times compared to its mono-culture biofilm. S. mutans also promoted substantial biofilm growth of lactobacilli but V. parvula had no effect. We conclude that these Actinomyces species promoted growth of key Lactobacillus species in a biofilm, as did S. mutans to a smaller extent, and that the ability of individual bacteria to form mono-culture biofilms is not necessarily an indicator of their survival and pathogenic potential in a complex multispecies biofilm community.
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Affiliation(s)
- S K Filoche
- Dental Research Group, Department of Pathology and Molecular Medicine, Wellington School of Medicine, Wellington, New Zealand
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31
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Pitula JS, Deck KM, Clarke SL, Anderson SA, Vasanthakumar A, Eisenstein RS. Selective inhibition of the citrate-to-isocitrate reaction of cytosolic aconitase by phosphomimetic mutation of serine-711. Proc Natl Acad Sci U S A 2004; 101:10907-12. [PMID: 15263083 PMCID: PMC503718 DOI: 10.1073/pnas.0404308101] [Citation(s) in RCA: 24] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2004] [Indexed: 11/18/2022] Open
Abstract
Iron-regulatory protein 1 (IRP1) is a dual-function protein with mutually exclusive roles as a posttranscriptional regulator of animal-cell iron metabolism or as the cytosolic isoform of the iron-sulfur enzyme aconitase (c-acon). Much effort has focused on the role of IRP1 in posttranscriptional gene regulation and in factors that influence its interconversion with c-acon, but little is known about the metabolic function and regulation of c-acon. The role of PKC-dependent phosphorylation of S711 on IRP1/c-acon function was examined. Phosphorylation state-specific antibodies revealed that S711 is phosphorylated by PKC in vitro and in human embryonic kidney cells treated with a PKC activator. In aco1 yeast, the phosphomimetic mutants S711D and S711E exhibited severely impaired aconitase function, whereas S711A and S711T were unaffected relative to the WT protein. Aconitase activity in yeast extracts displayed a similar pattern when assayed for capacity to convert citrate to isocitrate: WT, S711A, and S711T were active, but S711D and S711E activity was undetectable. In contrast, when measured by the conversion of isocitrate to cis-aconitate, S711D and S711E displayed substantial activity, indicating that phosphorylation impairs the citrate but not isocitrate mode of aconitase function. This possibility was confirmed in vivo by demonstrating that S711D and S711E specifically antagonized the requirement for isocitrate in two metabolic scenarios. Iron-responsive element RNA-binding affinity was unaffected by S711 mutations. Our results show that S711 is a target of phosphorylation capable of conferring distinct effects on c-acon function potentially dictating changes in cytosolic citrate/isocitrate metabolism.
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Affiliation(s)
- Joseph S Pitula
- Department of Nutritional Sciences, University of Wisconsin, Madison, 53706, USA
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32
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Klein CJ, Cunningham JM, Atkinson EJ, Schaid DJ, Hebbring SJ, Anderson SA, Klein DM, Dyck PJB, Litchy WJ, Thibodeau SN, Dyck PJ. The gene for HMSN2C maps to 12q23-24: a region of neuromuscular disorders. Neurology 2003; 60:1151-6. [PMID: 12682323 DOI: 10.1212/01.wnl.0000055900.30217.ea] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND Hereditary motor and sensory neuropathy type 2C (HMSN2C, Charcot-Marie-Tooth 2C [CMT2C]) is an autosomal dominant motor and sensory neuropathy involving limb, diaphragm, vocal cord, and intercostal muscles. OBJECTIVE To identify the chromosome localization for this disorder in one large American family of English and Scottish ethnicity. METHODS Variable clinical severity led the authors to combine several approaches to accurately identify affected patients. Genome-wide two-point linkage analysis, high-definition mapping, and multipoint and recombinant haplotype analyses were performed. Mutation analysis of the triplet repeat region of ataxin-2 was also carried out. RESULTS The initial genome-wide scan identified a region at 12q24, and fine mapping provided a maximal lod score of 4.73 (D12S1645 and D12S1583 at theta = 0.01 and 0, respectively). With multipoint analysis, a higher lod score of 5.17 was obtained and localized to the same region at 119.0 cM. Haplotype analysis narrowed the region to approximately 5.0 cM between D12S1646,D12S1330 and D12S105,D12S1339 (12q23.3-24.21). Ataxin-2, the gene responsible for spinocerebellar ataxia type 2 (SCA2), localizes to this region, but no triplet repeat expansion or point mutations within the repeat were found. CONCLUSIONS The gene for HMSN2C maps to 12q23-24. This region is associated with SCA2, scapuloperoneal spinal muscular atrophy, and congenital distal spinal muscular atrophy. Further studies are needed to demonstrate the specific gene alteration and its relationship with nearby genes.
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Affiliation(s)
- C J Klein
- Peripheral Neuropathy Research Laboratory, Mayo Clinic and Mayo Foundation, Rochester, MN, USA.
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33
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Wall-Manning GM, Sissons CH, Anderson SA, Lee M. Checkerboard DNA-DNA hybridisation technology focused on the analysis of Gram-positive cariogenic bacteria. J Microbiol Methods 2002; 51:301-11. [PMID: 12223290 DOI: 10.1016/s0167-7012(02)00106-9] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [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: 11/19/2022]
Abstract
Checkerboard DNA-DNA hybridisation enabled the quantitative analysis of plaque samples against 40 microbial species simultaneously, using digoxygenin-labelled, whole-genome DNA probes. This technique was initially developed to study the predominantly Gram-negative sub-gingival plaque microbiota. The aim of this study was to apply it to a suite of predominantly Gram-positive microorganisms, such as those implicated in cariogenesis. To specifically target Gram-positive species (and Candida albicans) required optimisation and modification of DNA extraction, prehybridisation, hybridisation, and antibody detection conditions. The suitability of the revised technique for clinical and epidemiological studies was confirmed using interproximal plaque from small groups of 5- to 6-year-old children of high (decayed, missing, or filled teeth (dmft)> or =5, n=8) and zero (n=5) caries rates.
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Affiliation(s)
- G M Wall-Manning
- Dental Research Group, Department of Pathology and Molecular Medicine, Wellington School of Medicine and Health Sciences, University of Otago, PO Box 7343, Wellington South, New Zealand
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34
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Lewis GD, Anderson SA, Turner SJ. Detection of enterococci in freshwater and seawater (16S and 23S rRNA Enterococcus oligonucleotide probes). Methods Mol Biol 2002; 179:159-69. [PMID: 11692860 DOI: 10.1385/1-59259-238-4:159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- G D Lewis
- School of Biological Sciences, University of Auckland, Auckland, New Zealand
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35
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Pearce EIF, Sissons CH, Coleman M, Wang X, Anderson SA, Wong L. The effect of sucrose application frequency and basal nutrient conditions on the calcium and phosphate content of experimental dental plaque. Caries Res 2002; 36:87-92. [PMID: 12037364 DOI: 10.1159/000057865] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
A reduced pool of calcium in dental plaque would be expected to increase the ability of plaque fluid to dissolve the underlying enamel when the pH falls during sugar exposure. We have examined the relationship between frequency of sugar application and Ca and P(i) concentrations in artificial mouth plaque microcosm biofilms. Ten plaques were grown simultaneously from a human saliva inoculum using a continuous flow of simulated saliva, DMM, supplemented with either urea or glucose to modulate the resting pH. In addition the plaques received sucrose applications of varying frequency: 12-, 8-, 6-, or 4-hourly, or not at all. After 15 days the plaques were sampled by taking 4 full-thickness specimens of each, and acid-extractable Ca and P(i), and alkali-soluble protein and carbohydrate were determined. Ca and P(i) concentrations were in a range comparable with those in human plaque, except in the DMM + urea plaque receiving no sucrose, when concentrations were higher. Plaque Ca concentration decreased significantly as sucrose application frequency increased. Increasing sucrose application frequency also reduced the protein, i.e. the cell biomass, content of the plaques and, in the case of DMM + urea plaques, increased the water-insoluble hexose content, presumably extracellular polysaccharide. Reduced biomass was partly due to the bulking of plaque with extracellular polysaccharide, but the marked effect of urea on polysaccharide formation is not understood. This study shows that increasing frequency of sugar application alters dental plaque by reducing its mineral protection capacity.
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Affiliation(s)
- E I F Pearce
- Wellington School of Medicine and Health Sciences, Wellington South, New Zealand.
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Abstract
This study describes the influence of grandmothers on parental competence among urban African American adolescent mothers, using a model adapted from Belsky's (1984) Determinants of Parenting Process Model. The sample included 53 pairs of urban African American mothers (age 16.4 +/- 1.2 years) and their mothers (age 39.2 +/- 4.3 years). All adolescents were enrolled in school, co-resided with mothers, and had infants ages 4 to 8 months. Survey instruments measured personal resources, perception of infant temperament, and contextual sources of support and stress. The outcome measure for adolescent mothers was perceived parental competence. Multiple regression analyses indicated adolescent mothers' self-esteem and mastery explained 41% of the variance and grandmothers' self-esteem explained 42% of the variance in adolescent mothers' parental competence. A combined regression equation demonstrated that adolescent mothers' mastery and grandmothers' self-esteem accounted for 65% of the variance in adolescent mothers' parental competence.
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Affiliation(s)
- L S Sadler
- Yale University School of Nursing, 100 Church Street South, New Haven, CT 06536-0740, USA.
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37
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Gonzalez E, Dhanda R, Bamshad M, Mummidi S, Geevarghese R, Catano G, Anderson SA, Walter EA, Stephan KT, Hammer MF, Mangano A, Sen L, Clark RA, Ahuja SS, Dolan MJ, Ahuja SK. Global survey of genetic variation in CCR5, RANTES, and MIP-1alpha: impact on the epidemiology of the HIV-1 pandemic. Proc Natl Acad Sci U S A 2001; 98:5199-204. [PMID: 11320252 PMCID: PMC33187 DOI: 10.1073/pnas.091056898] [Citation(s) in RCA: 178] [Impact Index Per Article: 7.7] [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: 01/25/2023] Open
Abstract
Expression of CC chemokine receptor 5 (CCR5), the major coreceptor for HIV-1 cell entry, and its ligands (e.g., RANTES and MIP-1alpha) is widely regarded as central to the pathogenesis of HIV-1 infection. By surveying nearly 3,000 HIV+ and HIV- individuals from worldwide populations for polymorphisms in the genes encoding RANTES, MIP-1alpha, and CCR5, we show that the evolutionary histories of human populations have had a significant impact on the distribution of variation in these genes, and that this may be responsible, in part, for the heterogeneous nature of the epidemiology of the HIV-1 pandemic. The varied distribution of RANTES haplotypes (AC, GC, and AG) associated with population-specific HIV-1 transmission- and disease-modifying effects is a striking example. Homozygosity for the AC haplotype was associated with an increased risk of acquiring HIV-1 as well as accelerated disease progression in European Americans, but not in African Americans. Yet, the prevalence of the ancestral AC haplotype is high in individuals of African origin, but substantially lower in non-Africans. In a Japanese cohort, AG-containing RANTES haplotype pairs were associated with a delay in disease progression; however, we now show that their contribution to HIV-1 pathogenesis and epidemiology in other parts of the world is negligible because the AG haplotype is infrequent in non-Far East Asians. Thus, the varied distribution of RANTES, MIP-1alpha, and CCR5 haplotype pairs and their population-specific phenotypic effects on HIV-1 susceptibility and disease progression results in a complex pattern of biological determinants of HIV-1 epidemiology. These findings have important implications for the design, assessment, and implementation of effective HIV-1 intervention and prevention strategies.
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Affiliation(s)
- E Gonzalez
- South Texas Veterans Health Care System, and University of Texas Health Science Center at San Antonio, San Antonio, TX 78229-3900, USA
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38
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Pinto LA, Blazevic V, Anderson SA, Venzon DJ, Trubey CM, Rowe T, Katz JM, Liewehr D, Dolan MJ, Shearer GM. Influenza virus-stimulated generation of anti-human immunodeficiency virus (HIV) activity after influenza vaccination in HIV-infected individuals and healthy control subjects. J Infect Dis 2001; 183:1000-8. [PMID: 11237823 DOI: 10.1086/319277] [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] [Received: 09/06/2000] [Revised: 11/21/2000] [Indexed: 11/03/2022] Open
Abstract
Influenza virus stimulation of leukocytes induces factors that suppress human immunodeficiency virus (HIV). The effect of influenza vaccination on influenza-induced anti-HIV activity was investigated. Influenza vaccine was administered to 25 control subjects and 20 HIV-infected patients. Antiviral activity, cytokine production, and influenza antibodies were assessed before and 2 and 6 weeks after vaccination. Immunization induced a statistically significant increase in antiviral activity in control subjects but not in HIV patients, although the number of patients who generated this activity increased. Pre- and postvaccination levels of anti-HIV activity were significantly lower in HIV patients. Vaccination of control subjects and HIV patients induced increases in production of interleukin-2 and interferon (IFN)-gamma, but not of IFN-alpha. Virus load and CD4 cell counts were not significantly altered. This study demonstrates impairment of antiviral activity in HIV patients, in addition to deficiencies in antibody responses and cytokine production. In summary, influenza vaccination can induce an increase in multiple immunologic components that remained impaired in HIV patients.
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Affiliation(s)
- L A Pinto
- Experimental Immunology Branch, National Cancer Institute, Bethesda, MD, USA
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39
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Kim AS, Anderson SA, Rubenstein JL, Lowenstein DH, Pleasure SJ. Pax-6 regulates expression of SFRP-2 and Wnt-7b in the developing CNS. J Neurosci 2001; 21:RC132. [PMID: 11222670 PMCID: PMC6762962] [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: 02/19/2023] Open
Abstract
Wnt signaling regulates a wide range of developmental processes such as proliferation, cell migration, axon guidance, and cell fate determination. In this report, we studied the expression of secreted frizzled related protein-2 (SFRP-2), which codes for a putative Wnt inhibitor, in the developing nervous system. SFRP-2 is expressed in several discrete neuroepithelial domains, including the diencephalon, the insertion of the eminentia thalami into the caudal telencephalon, and the pallial-subpallial boundary (PSB). We also noted that Wnt-7b expression was similar to SFRP-2 expression. Because many of these structures are disrupted in Pax-6 mutant mice, we examined SFRP-2 and Wnt-7b expression in the forebrains of Pax-6 Sey/Sey mice. We found that Pax-6 mutants lack SFRP-2 expression in the PSB and diencephalon. Interestingly, Pax-6 mutants also lack Wnt-7b expression in the PSB, but Wnt-7b expression in the diencephalon is preserved. Furthermore, in the spinal cord of Pax-6 mutants, SFRP-2 and Wnt-7b expression was greatly reduced. Our results suggest that by virtue of its apposition to Wnt-7b expression, SFRP-2 may modulate its function, particularly at boundaries such as the PSB, and that changes in Wnt signaling contribute to the phenotype of Pax-6 mutants.
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Affiliation(s)
- A S Kim
- Neurodevelopmental Disorders Laboratory, Department of Neurology, University of California, San Francisco, California 94143, USA
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40
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Parnavelas JG, Anderson SA, Lavdas AA, Grigoriou M, Pachnis V, Rubenstein JL. The contribution of the ganglionic eminence to the neuronal cell types of the cerebral cortex. Novartis Found Symp 2001; 228:129-39; discussion 139-47. [PMID: 10929320 DOI: 10.1002/0470846631.ch10] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
The principal neuronal types of the mammalian cerebral cortex are the excitatory pyramidal cells and the inhibitory interneurons, the non-pyramidal cells. It is thought that these neurons arise in the ventricular zone surrounding the telencephalic ventricles. From there, newly generated neurons migrate outward along the processes of radial glial cells to reach the cortical plate where they accumulate in an 'inside-out' sequence to form the six-layered structure of the neocortex. Here we review emerging evidence that pyramidal neurons are generated in the cortical ventricular zone, whereas the majority of the non-pyramidal cells arise in the ganglionic eminences of the ventral telencephalon. These neurons follow tangential migratory routes to reach their positions in the developing cortex.
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Affiliation(s)
- J G Parnavelas
- Department of Anatomy and Developmental Biology, University College London, UK
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Abstract
Recent evidence suggests that projection neurons and interneurons of the cerebral cortex are generally derived from distinct proliferative zones. Cortical projection neurons originate from the cortical ventricular zone (VZ), and then migrate radially into the cortical mantle, whereas most cortical interneurons originate from the basal telencephalon and migrate tangentially into the developing cortex. Previous studies using methods that label both proliferative and postmitotic cells have found that cortical interneurons migrate from two major subdivisions of the developing basal telencephalon: the medial and lateral ganglionic eminences (MGE and LGE). Since these studies labeled cells by methods that do not distinguish between the proliferating cells and those that may have originated elsewhere, we have studied the contribution of the MGE and LGE to cortical interneurons using fate mapping and genetic methods. Transplantation of BrdU-labeled MGE or LGE neuroepithelium into the basal telencephalon of unlabeled telencephalic slices enabled us to follow the fate of neurons derived from each of these primordia. We have determined that early in neurogenesis GABA-expressing cells from the MGE tangentially migrate into the cerebral cortex, primarily via the intermediate zone, whereas cells from the LGE do not. Later in neurogenesis, LGE-derived cells also migrate into the cortex, although this migration occurs primarily through the subventricular zone. Some of these LGE-derived cells invade the cortical plate and express GABA, while others remain within the cortical proliferative zone and appear to become mitotically active late in gestation. In addition, by comparing the phenotypes of mouse mutants with differential effects on MGE and LGE migration, we provide evidence that the MGE and LGE may give rise to different subtypes of cortical interneurons.
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Affiliation(s)
- S A Anderson
- Nina Ireland Laboratory of Developmental Neuroscience, Department of Psychiatry, University of California, San Francisco, CA 94143-0984, USA
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42
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Abstract
One of the proposed mechanisms for resistance to human immunodeficiency virus-1 (HIV-1) infection is the presence of antibodies against receptor for CC-chemokines (CCR5). These antibodies, detected in sera of uninfected individuals exposed to HIV, have been shown to downmodulate surface CCR5 in vivo and are able to neutralize the infectivity of CCR5 strains in vitro. To address the potential role of anti-CCR5 antibodies in HIV infection, we analyzed anti-CCR5 antibody levels in plasma from HIV-infected patients who present a wide range of CD4(+) T-cell counts and viral load. Increased levels of anti-CCR5 antibodies were found in plasma from 13/46 HIV-positive donors compared with healthy controls (0/36). However, antibody levels were not associated with disease stage evaluated by CD4(+) T-cell counts and viral load.
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Affiliation(s)
- E Grene
- Experimental Immunology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
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43
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Anderson SA, Rader RK, Westlin WF, Null C, Jackson D, Lanza GM, Wickline SA, Kotyk JJ. Magnetic resonance contrast enhancement of neovasculature with alpha(v)beta(3)-targeted nanoparticles. Magn Reson Med 2000; 44:433-9. [PMID: 10975896 DOI: 10.1002/1522-2594(200009)44:3<433::aid-mrm14>3.0.co;2-9] [Citation(s) in RCA: 189] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Site-directed contrast enhancement of angiogenic vessels in vivo was demonstrated using antibody targeting of an MRI contrast agent to the alpha(v)beta(3) integrin, a molecular marker characteristic of angiogenic endothelium. The agent was tested in a rabbit corneal micropocket model, in which neovasculature is induced in the cornea using basic fibroblast growth factor. The targeted contrast agent consists of Gd-perfluorocarbon nanoparticles linked to alpha(v)beta(3) integrin antibody DM101. The animal group receiving the targeted contrast agent displayed a 25% increase in the average MR signal intensity after 90 min. Control groups in which the nanoparticles are either used alone, linked to an isotype-matched antibody, or linked to DM101 and administered following receptor blocking did not display MR contrast enhancement at similar dose levels. These findings indicate that the antibody-targeted agent enhances MR signal intensity in the capillary bed in a corneal micropocket model of angiogenesis, and is selectively retained within the angiogenic region via specific interaction with the alpha(v)beta(3) epitope.
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MESH Headings
- Animals
- Antibodies, Monoclonal/chemistry
- Antibodies, Monoclonal/metabolism
- Antibody Specificity
- Biotinylation
- Contrast Media/administration & dosage
- Contrast Media/chemistry
- Cornea/blood supply
- Cornea/pathology
- Corneal Neovascularization/chemically induced
- Corneal Neovascularization/diagnosis
- Corneal Neovascularization/metabolism
- Corneal Neovascularization/pathology
- Disease Models, Animal
- Dose-Response Relationship, Drug
- Fibroblast Growth Factor 2
- Fluorocarbons/administration & dosage
- Gadolinium/administration & dosage
- Image Enhancement/methods
- Immunohistochemistry
- Injections, Intravenous
- Magnetic Resonance Angiography/methods
- Microspheres
- Neovascularization, Pathologic/chemically induced
- Neovascularization, Pathologic/diagnosis
- Neovascularization, Pathologic/metabolism
- Neovascularization, Pathologic/pathology
- Rabbits
- Receptors, Vitronectin/immunology
- Receptors, Vitronectin/metabolism
- Thrombomodulin/metabolism
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44
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Marin O, Anderson SA, Rubenstein JL. Origin and molecular specification of striatal interneurons. J Neurosci 2000; 20:6063-76. [PMID: 10934256 PMCID: PMC6772576] [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] [Received: 02/28/2000] [Revised: 05/17/2000] [Accepted: 05/19/2000] [Indexed: 02/17/2023] Open
Abstract
The striatum, the largest component of the basal ganglia, contains projection neurons and interneurons. Whereas there is considerable agreement that the lateral ganglionic eminence (LGE) is the origin of striatal projection neurons, less is known about the origin of striatal interneurons. Using focal injections of retrovirus into the ventral telencephalon in vitro, we demonstrate that most striatal interneurons tangentially migrate from the medial ganglionic eminence (MGE) or the adjacent preoptic/anterior entopeduncular areas (POa/AEP) and express the NKX2.1 homeodomain protein. Although the majority of striatal interneurons (cholinergic, calretinin(+), and parvalbumin(+)) maintain the expression of NKX2.1 into adulthood, most of the interneurons expressing somatostatin (SOM), neuropeptide Y (NPY), and neural nitric oxide synthase (NOS) appear to downregulate the expression of NKX2.1 as they exit the neuroepithelium. Analysis of striatal development in mice lacking Nkx2.1 suggests that this gene is required for the specification of nearly all striatal interneurons. Similar analysis of mice lacking the Mash1 basic helix-loop-helix (bHLH) or both the Dlx1 and Dlx2 homeodomain transcription factors demonstrates that these genes are required for the differentiation of striatal interneurons. Mash1 mutants primarily have a reduction in early-born striatal interneurons, whereas Dlx1/2 mutants primarily have reduced numbers of late-born striatal interneurons. We also present evidence implicating the Lhx6 and Lhx7 LIM-homeobox genes in the development of distinct interneuron subtypes. Finally, we hypothesize that, within the MGE, radially migrating cells generally become projection neurons, whereas tangentially migrating cells mainly form interneurons of the striatum and cerebral cortex.
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Affiliation(s)
- O Marin
- Department of Psychiatry, Nina Ireland Laboratory of Developmental Neurobiology, Langley Porter Psychiatric Institute, University of California, San Francisco, San Francisco, California 94143-0984, USA
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Abstract
The potential toxicity of RTI 4587-056, a hexahydroindenopyridine analog of SANDOZ 20-438, was examined in adult male Sprague-Dawley rats. Testicular, intestinal, and erythropoietic histology was assessed after 28 days of gavage treatment at 0, 10, and 100 mg/kg/day. During the first 10 days, dose-related clinical signs included mild to moderate lethargy shortly after dosing, lower consumption of feed and water, and body weight loss or decreased weight gain. Tolerance developed, such that lethargy disappeared and weight gains were equivalent to the control group during the second through fourth weeks. The compound did not affect intestinal epithelium or bone marrow. RTI 4587-056 was a highly effective antispermatogenic agent at both doses causing epididymal hypospermia and testicular atrophy. Based upon the Spermatogenic Index ratings, still lower doses would be effective male contraceptive agents. RTI 4587-056 has potential as a male contraceptive without overt side effects. Further testing is required.
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Affiliation(s)
- P A Fail
- Chemistry and Life Sciences Unit, Research Triangle Institute, P.O. Box 12194, Research Triangle Park, NC 27709-2194, USA.
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Smalley RV, Guaspari A, Haase-Statz S, Anderson SA, Cederberg D, Hohneker JA. Allopurinol: intravenous use for prevention and treatment of hyperuricemia. J Clin Oncol 2000; 18:1758-63. [PMID: 10764437 DOI: 10.1200/jco.2000.18.8.1758] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
PURPOSE To tabulate data obtained over a 21-year period to determine the efficacy and safety of an intravenous (IV) allopurinol preparation. PATIENTS AND METHODS IV allopurinol was provided on a compassionate plea basis to patients of any age in whom xanthine oxidase inhibitor therapy was indicated as an adjunct to chemotherapy and for whom oral intake was restricted. Three hundred twenty-seven investigators at multiple hospitals in the United States treated 1,172 patients with IV allopurinol. The vast majority of these patients had a malignancy and were in danger of developing tumor lysis syndrome (TLS) and subsequent acute uric acid nephropathy (AUAN) and were unable to take oral allopurinol. Data referable to the time period of IV allopurinol administration were collected, collated, and analyzed retrospectively. There was no randomization. RESULTS In patients initiating treatment for an elevated serum uric acid (SUA), the SUA normalized or improved in 87% of adult patients and normalized or improved in 95% of pediatric patients. IV allopurinol, administered prophylactically to patients at high risk of developing hyperuricemia and TLS, prevented an increase in SUA levels in 93% of adults and 92% of children. Toxicities caused by IV allopurinol were minimal and consisted of 10 instances of mild to moderate skin or allergic reactions. CONCLUSION IV allopurinol is as efficacious and safe as oral allopurinol and will be of significant benefit to patients at risk of TLS and AUAN and unable to take oral medication.
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Affiliation(s)
- R V Smalley
- Synertron, Inc, Madison, WI 53705-0630, USA.
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Abstract
Supervisees in Commission on Accreditation for Marriage and Family Therapy Education-(COAMFTE) accredited and candidacy training programs were asked to describe their best and worst supervision experiences in terms of the context of training and supervision, the perceived personal attributes of the supervisor, and specific behaviors perceived to be enacted by the supervisor during supervision. Contextual factors such as supervision modality, frequency and duration of supervisory contacts, and sources of supervisory data appeared to distinguish between supervisees' perceptions of their best and worst experiences. These experiences were further distinguished by the supervisees' perceptions regarding the supervisor's level of interpersonal attractiveness, trustworthiness, and expertise. Key behaviors perceived to be enacted by supervisors during best and worst experiences clustered into several dimensions that included creating an open supervisory environment, communication and encouragement, attending to personal growth, and providing conceptual and technical guidance and direction.
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Affiliation(s)
- S A Anderson
- Marital and Family Therapy Program, University of Connecticut, School of Family Studies, Storrs 06269, USA
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Eisenstat DD, Liu JK, Mione M, Zhong W, Yu G, Anderson SA, Ghattas I, Puelles L, Rubenstein JL. DLX-1, DLX-2, and DLX-5 expression define distinct stages of basal forebrain differentiation. J Comp Neurol 1999; 414:217-37. [PMID: 10516593 DOI: 10.1002/(sici)1096-9861(19991115)414:2<217::aid-cne6>3.0.co;2-i] [Citation(s) in RCA: 240] [Impact Index Per Article: 9.6] [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: 11/12/2022]
Abstract
The homeobox genes in the Dlx family are required for differentiation of basal forebrain neurons and craniofacial morphogenesis. Herein, we studied the expression of Dlx-1, Dlx-2, and Dlx-5 RNA and protein in the mouse forebrain from embryonic day 10.5 (E10.5) to E12.5. We provide evidence that Dlx-2 is expressed before Dlx-1, which is expressed before Dlx-5. We also demonstrate that these genes are expressed in the same cells, which may explain why single mutants of the Dlx genes have mild phenotypes. The DLX proteins are localized primarily to the nucleus, although DLX-5 also can be found in the cytoplasm. During development, the fraction of Dlx-positive cells increases in the ventricular zone. Analysis of the distribution of DLX-1 and DLX-2 in M-phase cells suggests that these proteins are distributed symmetrically to daughter cells during mitosis. We propose that DLX-negative cells in the ventricular zone are specified progressively to become DLX-2-expressing cells during neurogenesis; as these cells differentiate, they go on to express DLX-1, DLX-5, and DLX-6. This process appears to be largely the same in all regions of the forebrain that express the Dlx genes. In the basal telencephalon, these DLX-positive cells differentiate into projection neurons of the striatum and pallidum as well as interneurons, some of which migrate to the cerebral cortex and the olfactory bulb.
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Affiliation(s)
- D D Eisenstat
- Nina Ireland Laboratory of Developmental Neurobiology, Center for Neurobiology and Psychiatry, Department of Psychiatry and Programs in Neuroscience and Developmental Biology, University of California at San Francisco, California 94143-0984, USA
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Abstract
Modulation of endocrine function is frequently a confounding factor in the interpretation of chronic rodent toxicology studies. Of particular interest are agents that cause deviation of thyroid hormone homeostasis and result in thyroid cancer for rodents. An endocrine challenge test (ECT), commonly used to study endocrine organ health in human and veterinary medicine, quantifies the response of the thyroid to tropic hormones. This study compared the response of Fischer (F344) and Sprague-Dawley (SD) rats to a thyrotropin-releasing hormone (TRH) ECT and a thyroid-stimulating hormone (TSH) ECT and characterized the dose-response curve. TSH, thyroxine (T4), triiodothyronine (T3), and prolactin responses were characterized for several doses of TRH over a 4-h time period. Animals were equipped with intra-atrial cannulae and were free moving at all times during blood sampling. Both strains of rats responded to intravenous TRH by releasing TSH into their blood in a dose-responsive fashion. At doses of > or = 100 ng, TSH concentrations were increased by more than 2-fold at 2 min. Concentrations reached a maximum at 15 min for doses of 100 ng/100 g body weight (bw) to 5000 ng/100g bw. The effective dose 50 (ED50) of TRH (that dose causing release of half maximal TSH concentrations) was 61 ng in F344 rats and 78 ng in SD rats. The ED75 was 173 ng and 217 ng/100 g bw, respectively. The response of T4 and T3 after TRH ECT and TSH ECT was highly variable. F344 rats responded with an increase in levels of both hormones, starting at 60 min and continuing through 240 min. In SD rats, the presence of a thyroid hormone response (T4) was present, although that of T3 was not clear. These data provide essential information for design of toxicology studies focused on the effects of toxicants and drugs on the pituitary-thyroid axis.
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Affiliation(s)
- P A Fail
- Research Triangle Institute, Research Triangle Park, North Carolina 27709-2194, USA.
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