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St Pierre-Hetz R, Cramer N. Delayed Neonatal Scalp Swelling: A Rare Case of Subaponeurotic Fluid Collection. Neuropediatrics 2023; 54:157-158. [PMID: 35977706 DOI: 10.1055/a-1926-2139] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
Affiliation(s)
- Ryan St Pierre-Hetz
- Department of Pediatric Emergency Medicine, Children's Hospital of Pittsburgh, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, United States
| | - Natan Cramer
- Department of Pediatric Emergency Medicine, Children's Hospital of Pittsburgh, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, United States
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2
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Beardsley J, McCoy A, Freeman M, Cramer N, Neville D, Owusu-Ansah S, Houtrow A, Sinha A. The complete acute and post-acute care course of children affected by acute flaccid myelitis in Western Pennsylvania: A case series. J Pediatr Rehabil Med 2023; 16:401-413. [PMID: 36776079 DOI: 10.3233/prm-210120] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/12/2023] Open
Abstract
Acute flaccid myelitis (AFM) is a "polio-like" neurologic disorder of the spinal cord gray matter characterized by asymmetric, flaccid limb weakness of rapid onset following prodromal viral illness. It has affected the pediatric population of the United States since 2014, but there is a paucity of literature describing the post-acute comprehensive rehabilitation management that maximizes functional outcomes for patients. This case series attempts to mitigate this by describing the complete acute and post-acute care course of six children diagnosed with AFM in Western Pennsylvania. It is critical that pediatric rehabilitation medicine providers be knowledgeable about the complex medical and rehabilitation management for patients with AFM.
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Affiliation(s)
| | - Andrew McCoy
- UPMC Physical Medicine and Rehabilitation, Pittsburgh, PA, USA
| | - Megan Freeman
- Pediatric Infectious Disease, UPMC Children's Hospital of Pittsburgh, Pittsburgh, PA, USA
| | - Natan Cramer
- Pediatric Emergency Medicine, UPMC Children's Hospital of Pittsburgh, Pittsburgh, PA, USA
| | - Desiree Neville
- Pediatric Emergency Medicine, UPMC Children's Hospital of Pittsburgh, Pittsburgh, PA, USA
| | - Silvia Owusu-Ansah
- Pediatric Emergency Medicine, UPMC Children's Hospital of Pittsburgh, Pittsburgh, PA, USA
| | - Amy Houtrow
- Pediatric Rehabilitation Medicine, UPMC Children's Hospital of Pittsburgh, Pittsburgh, PA, USA
| | - Amit Sinha
- Pediatric Rehabilitation Medicine, UPMC Children's Hospital of Pittsburgh, Pittsburgh, PA, USA
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3
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Cramer N, Aspiotes CR, Pitetti RD. Ferret bite causing a near-death in an infant: An opportunity for paediatric advocacy. J Paediatr Child Health 2023; 59:180-181. [PMID: 36129202 DOI: 10.1111/jpc.16224] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 09/06/2022] [Accepted: 09/07/2022] [Indexed: 01/14/2023]
Affiliation(s)
- Natan Cramer
- Department of Pediatrics, Division of Emergency Medicine, Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania, United States
| | - Christine R Aspiotes
- Department of Pediatrics, Division of Emergency Medicine, Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania, United States
| | - Raymond D Pitetti
- Department of Pediatrics, Division of Emergency Medicine, Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania, United States
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4
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Cramer N. Transverse Myelitis in a Child with Chronic Recurrent Multifocal Osteomyelitis. Neurohospitalist 2022; 12:579-580. [DOI: 10.1177/19418744221092881] [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: 11/16/2022] Open
Abstract
A 16-year-old girl with a history of clavicular chronic recurrent multifocal osteomyelitis (CRMO) presented with fever, vomiting, urinary and bowel retention, thigh paresthesia, and back pain for 2 days. The patient had 2 separate viral illnesses within a month prior to presentation. Spine magnetic resonance imaging (MRI) displayed increased T2 hyperintensity of the central grey matter from C3 to the conus medullaris (Figure 1). Findings were consistent with longitudinally extensive transverse myelitis. Cerebrospinal fluid analysis revealed elevated protein (51; reference range: <48 mg/dL), IgG index (.74; reference range <.70), and glucose (99; reference range 40-75 mg/dL). There was pleocytosis of 22 white blood cells (88% lymphocytes and 12% monocytes) with negative AQP4 and MOG antibodies. COVID-19 spike protein was positive with a negative PCR and non-immunized status, suggesting prior infection. Four months later, a pelvic MRI revealed new evidence of CRMO.
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Affiliation(s)
- Natan Cramer
- UPMC Children’s Hospital of Pittsburgh, Division of Pediatric Emergency Medicine, Pittsburgh, PA, USA
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5
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Cramer N, Zuckerbraun NS, Puller J, Furtado AD, Deb A, Dorfsman ML, Siripong N, Christie M, Tavarez MM. Putting Theory to Practice: Applying Cognitive Load Theory to Resident Medical Education. Pediatr Emerg Care 2022; 38:e771-e775. [PMID: 35100776 DOI: 10.1097/pec.0000000000002371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE We built 2 versions of an asynchronous pediatric orthopedic educational intervention for emergency medicine residents and sought to compare the two. We hypothesized that the version incorporating more instructional scaffolding in the form of a cognitive aid (CA) would optimize germane cognitive load for our target novice learners and result in higher test scores. METHODS Learners were block randomized to either a "CA" or "non-CA" arm, each containing a random set of 18 modules. The CA arm incorporated an orthopedic fracture classification chart embedded within the diagnostic questions to guide the learner in forming a diagnosis. The non-CA arm was designed with more active learning as the classification chart was provided only after each diagnostic answer submission. For both arms, the final 6 modules completed per learner were scored. Learners also completed a perceived cognitive load assessment tool measured on a 10-point Likert scale. RESULTS Learners in the non-CA arm had a mean total score on the testing modules of 33% correct compared with a mean total score of 44% correct for learners in the CA arm (mean difference, 11; 95% confidence interval, 4%-19%, P = 0.005). There was a trend for the CA arm to have lower perceived overall cognitive load scores; however, this did not reach statistical significance. CONCLUSIONS Emergency medicine residents performed better after completing the CA version of our educational intervention. Applying cognitive load theory to an educational intervention may increase its success among target learners.
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Affiliation(s)
- Natan Cramer
- From the Department of Emergency Medicine, Children's Hospital of Pittsburgh of UPMC, Pittsburgh
| | - Noel Spears Zuckerbraun
- From the Department of Emergency Medicine, Children's Hospital of Pittsburgh of UPMC, Pittsburgh
| | | | - Andre D Furtado
- Department of Radiology, Children's Hospital of Pittsburgh of UPMC
| | - Arjamon Deb
- Department of Emergency Medicine, UPMC Presbyterian
| | | | - Nalyn Siripong
- Clinical and Translational Science Institute, University of Pittsburgh, Pittsburgh, PA
| | | | - Melissa M Tavarez
- From the Department of Emergency Medicine, Children's Hospital of Pittsburgh of UPMC, Pittsburgh
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6
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Cramer N, Cantwell L, Ong H, Sivasankar SM, Graff D, Lawson SL, Wilson PM, Noorbakhsh KA, Mickley M, Zuckerbraun NS, Sobolewski B, Soung JK, Azhdam DB, Wagner Neville DN, Hincapie MR, Marin JR. Pediatric emergency medicine fellowship point-of-care ultrasound training in 2020. AEM Educ Train 2021; 5:e10643. [PMID: 34568713 PMCID: PMC8448484 DOI: 10.1002/aet2.10643] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 06/24/2021] [Accepted: 06/30/2021] [Indexed: 06/13/2023]
Abstract
OBJECTIVES The primary objective was to survey pediatric emergency medicine (PEM) leaders and fellows regarding point-of-care ultrasound (POCUS) training in PEM fellowship programs, including teaching methods, training requirements, and applications taught. Secondary objectives were to compare fellows' and program leaders' perceptions of fellow POCUS competency and training barriers. METHODS This was a cross-sectional survey of U.S. PEM fellows and fellowship program leaders of the 78 fellowship programs using two online group-specific surveys exploring five domains: program demographics; training strategies and requirements; perceived competency; barriers, strengths, and weaknesses of POCUS training; and POCUS satisfaction. RESULTS Eighty-three percent (65/78) of programs and 53% (298/558) of fellows responded. All participating PEM fellowship programs included POCUS training in their curriculum. Among the 65 programs, 97% of programs and 92% of programs utilized didactics and supervised scanning shifts as educational techniques, respectively. Sixty percent of programs integrated numerical benchmarks and 49% of programs incorporated real-time, hands-on demonstration as training requirements. Of the 19 POCUS applications deemed in the literature as core requirements for fellows, at least 75% of the 298 fellows reported training in 13 of those applications. Although less than half of fellows endorsed competency for identifying intussusception, ultrasound-guided pericardiocentesis, and transvaginal pregnancy evaluation, a higher proportion of leaders reported fellows as competent for these applications (40% vs. 68%, p ≤ 0.001; 21% vs. 39%, p = 0.003; and 21% vs. 43%, p ≤ 0.001). Forty-six percent of fellows endorsed a lack of PEM POCUS evidence as a training barrier compared to 31% of leaders (p = 0.02), and 39% of leaders endorsed a lack of local financial support as a training barrier compared to 23% of fellows (p = 0.01). CONCLUSIONS Although most PEM fellowship programs provide POCUS training, there is variation in content and requirements. Training does conform to many of the expert recommended guidelines; however, there are some discrepancies and perceived barriers to POCUS training remain.
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Affiliation(s)
- Natan Cramer
- Department of Emergency MedicineUPMC Children's Hospital of PittsburghPittsburghPennsylvaniaUSA
| | - Lauren Cantwell
- Department of Emergency MedicineStanford University School of MedicinePalo AltoCaliforniaUSA
| | - Hilary Ong
- Department of Emergency Medicine and Trauma ServicesChildren's National HospitalWashingtonDCUSA
- Present address:
Department of Emergency MedicineUCSF Benioff Children's HospitalSan FranciscoCaliforniaUSA
| | - Shyam M. Sivasankar
- Department of Emergency MedicineStanford University School of MedicinePalo AltoCaliforniaUSA
- Dell Medical School Department of PediatricsAustinTexasUSA
| | - Danielle Graff
- Division of Emergency MedicineDepartment of PediatricsNorton Children's HospitalUniversity of Louisville School of MedicineLouisvilleKentuckyUSA
| | - Simone L. Lawson
- Department of Emergency Medicine and Trauma ServicesChildren's National HospitalWashingtonDCUSA
| | - Paria M. Wilson
- Department of PediatricsUniversity of Cincinnati College of MedicineCincinnatiOhioUSA
- Division of Emergency MedicineCincinnati Children's Hospital Medical CenterCincinnatiOhioUSA
| | - Kathleen A. Noorbakhsh
- Department of Emergency MedicineUPMC Children's Hospital of PittsburghPittsburghPennsylvaniaUSA
| | - Megan Mickley
- Section of Pediatric Emergency MedicineDepartment of PediatricsChildren's Hospital ColoradoAuroraColoradoUSA
| | - Noel S. Zuckerbraun
- Department of Emergency MedicineUPMC Children's Hospital of PittsburghPittsburghPennsylvaniaUSA
| | - Brad Sobolewski
- Department of PediatricsUniversity of Cincinnati College of MedicineCincinnatiOhioUSA
- Division of Emergency MedicineCincinnati Children's Hospital Medical CenterCincinnatiOhioUSA
| | - Jane K. Soung
- Department of Emergency MedicineUPMC Children's Hospital of PittsburghPittsburghPennsylvaniaUSA
| | - Devora B. Azhdam
- Department of Emergency MedicineUPMC Children's Hospital of PittsburghPittsburghPennsylvaniaUSA
| | | | - Mark R. Hincapie
- Department of Emergency MedicineUPMC Children's Hospital of PittsburghPittsburghPennsylvaniaUSA
| | - Jennifer R. Marin
- Department of Emergency MedicineUPMC Children's Hospital of PittsburghPittsburghPennsylvaniaUSA
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Abstract
ABSTRACT Classic appendicitis is a common condition easily diagnosed by emergency care providers. However, atypical cases represent a diagnostic challenge and can contribute to increased morbidity from a delay in definitive care. It is important to recognize that atypical presentations have an increased risk for underlying anatomic variants, which may require additional imaging as part of management. We present a case of a 13-year-old previously healthy adolescent boy with acute onset of left-sided abdominal pain who was found to have appendicitis in the setting of underlying malrotation.
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Affiliation(s)
- Natan Cramer
- From the Pediatric Emergency Medicine Fellow, Children's Hospital of Division of Emergency Medicine at the University of Pittsburgh Medical Center, Children's Hospital of Pittsburgh, Pittsburgh, PA
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8
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Cramer N, Nawrot ML, Wege L, Fischer S, Sommer C, Danov O, Wronski S, Braun A, Munder A, Tümmler B. P150 Competitive fitness experiments of cystic fibrosis isolates of Pseudomonas aeruginosa in human and murine precision-cut lung slices. J Cyst Fibros 2021. [DOI: 10.1016/s1569-1993(21)01176-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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9
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Cramer N, Azhdam D. A 6-month-old infant girl presents with neck stiffness. J Stomatol Oral Maxillofac Surg 2020; 121:749-750. [PMID: 32224202 DOI: 10.1016/j.jormas.2020.03.019] [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] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Accepted: 03/23/2020] [Indexed: 06/10/2023]
Affiliation(s)
- N Cramer
- Division of Pediatric Emergency Medicine, AOB 2400, UPMC Children's Hospital of Pediatrics, 4401, Penn Avenue, 15224 Pittsburgh, PA, United States.
| | - D Azhdam
- Division of Pediatric Emergency Medicine, AOB 2400, UPMC Children's Hospital of Pediatrics, 4401, Penn Avenue, 15224 Pittsburgh, PA, United States.
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Cramer N, Rau K, Owusu-Ansah S. Lesson learned: Don't forget about the ovaries in female toddlers presenting with abdominal pain. Pediatr Neonatol 2020; 61:561-562. [PMID: 32561142 DOI: 10.1016/j.pedneo.2020.05.006] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 05/06/2020] [Accepted: 05/26/2020] [Indexed: 11/27/2022] Open
Affiliation(s)
- Natan Cramer
- Division of Emergency Medicine, Department of Pediatrics, University of Pittsburgh Medical Center (UPMC) Children's Hospital of Pittsburgh, 4401 Penn Ave, Pittsburgh, PA, 15224, USA.
| | - Katie Rau
- Division of Emergency Medicine, Department of Pediatrics, University of Pittsburgh Medical Center (UPMC) Children's Hospital of Pittsburgh, 4401 Penn Ave, Pittsburgh, PA, 15224, USA.
| | - Sylvia Owusu-Ansah
- Division of Emergency Medicine, Department of Pediatrics, University of Pittsburgh Medical Center (UPMC) Children's Hospital of Pittsburgh, 4401 Penn Ave, Pittsburgh, PA, 15224, USA.
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11
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Cramer N, Manole M. Unresponsive 4-Year-Old Boy Found to Have X-Linked Adrenoleukodystrophy. Neuropediatrics 2020; 51:83-84. [PMID: 31663106 DOI: 10.1055/s-0039-1697622] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- Natan Cramer
- Division of Pediatric Emergency Medicine, UPMC Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania, United States
| | - Mioara Manole
- Division of Pediatric Emergency Medicine, UPMC Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania, United States
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12
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Ramgopal S, Cramer N, Gaines BA, Conti KA. Risk Factors and Outcomes From All-Terrain Vehicle Injuries Compared With Motor Vehicle Collisions in Children. Clin Pediatr (Phila) 2019; 58:1255-1261. [PMID: 31189332 DOI: 10.1177/0009922819855808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We compared risk factors and outcomes of children injured from all-terrain vehicle (ATV) injuries to those injured from motor vehicle collisions (MVC). We reviewed records of patients ≤18 years of age admitted to a trauma center with ATV- or MVC-related injuries between January 1, 2000, and December 31, 2015. Demographics were compared using logistic regression. Rates of injuries were compared using χ2 tests. Of 6293 patients, 1140 (18%) ATV and 5153 (82%) MVC events were identified. In multivariable analysis (adjusted odds ratio [aOR], 95% confidence interval [CI]), patients with ATV-related injuries occurred more at older age (≥12 years; aOR = 4.29, 95% CI = 3.20-5.77), in rural counties (aOR = 3.72, 95% CI = 2.62-5.28), in regions with lower median household income (aOR = 1.37, 95% CI = 1.03-1.83), and in the spring (aOR = 2.44, 95% CI = 1.87-3.18), and summer (aOR = 2.50, 95% CI = 1.93-3.25) compared with winter. ATV-related injuries occurred less frequently among females (aOR = 0.76, 95% CI = 0.65-0.89). Upper extremity injuries were associated with ATV-related injuries (P ≤ .001). Findings may facilitate identification of at-risk groups for targeted interventions.
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Affiliation(s)
- Sriram Ramgopal
- University of Pittsburgh, Pittsburgh, PA, USA.,Children's Hospital of Pittsburgh, Pittsburgh, PA, USA
| | - Natan Cramer
- University of Pittsburgh, Pittsburgh, PA, USA.,Children's Hospital of Pittsburgh, Pittsburgh, PA, USA
| | - Barbara A Gaines
- University of Pittsburgh, Pittsburgh, PA, USA.,Children's Hospital of Pittsburgh, Pittsburgh, PA, USA
| | - Kavitha A Conti
- University of Pittsburgh, Pittsburgh, PA, USA.,Children's Hospital of Pittsburgh, Pittsburgh, PA, USA
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13
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Cramer N, Munjal N, Ware D, Ramgopal S, Simon D, Freeman MC, Michaels MG, Stem C, Thakkar K, Williams JV, Panigrahy A, Neville DNW, Owusu-Ansah S. New Cluster of Acute Flaccid Myelitis in Western Pennsylvania. Ann Emerg Med 2019; 74:503-508. [PMID: 30826069 DOI: 10.1016/j.annemergmed.2019.01.024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2018] [Indexed: 01/17/2023]
Abstract
Acute flaccid myelitis is a debilitating illness characterized by acute onset of limb weakness, with one or more spinal segments displaying magnetic resonance imaging-confirmed gray matter lesions. Since the first outbreak in 2014, tracking by the Centers for Disease Control and Prevention has demonstrated biennial epidemics in the United States, with a current outbreak occurring in 2018. The cases of 3 children with acute flaccid myelitis who were initially thought to have common nonneurologic diagnoses are presented. Emergency physicians need to be vigilant to recognize the subtleties of acute flaccid myelitis because the illness progression is rapid and therapy is nuanced.
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Affiliation(s)
- Natan Cramer
- Department of Pediatrics, Division of Pediatric Emergency Medicine, UPMC Children's Hospital of Pittsburgh, Pittsburgh, PA
| | - Neil Munjal
- Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA
| | | | - Sriram Ramgopal
- Department of Pediatrics, Division of Pediatric Emergency Medicine, UPMC Children's Hospital of Pittsburgh, Pittsburgh, PA
| | - Dennis Simon
- Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA
| | - Megan C Freeman
- Department of Pediatrics, Division of Pediatric Infectious Diseases, UPMC Children's Hospital of Pittsburgh, Pittsburgh, PA
| | - Marian G Michaels
- Department of Pediatrics, Division of Pediatric Infectious Diseases, UPMC Children's Hospital of Pittsburgh, Pittsburgh, PA
| | - Christopher Stem
- Department of Pediatrics, Division of Pediatric Emergency Medicine, UPMC Children's Hospital of Pittsburgh, Pittsburgh, PA
| | - Kavita Thakkar
- Department of Pediatrics, Division of Child Neurology, UPMC Children's Hospital of Pittsburgh, Pittsburgh, PA
| | - John V Williams
- Department of Pediatrics, Division of Pediatric Infectious Diseases, UPMC Children's Hospital of Pittsburgh, Pittsburgh, PA
| | - Ashok Panigrahy
- Department of Pediatric Radiology, UPMC Children's Hospital of Pittsburgh, Pittsburgh, PA
| | - Desiree N W Neville
- Department of Pediatrics, Division of Pediatric Emergency Medicine, UPMC Children's Hospital of Pittsburgh, Pittsburgh, PA
| | - Sylvia Owusu-Ansah
- Department of Pediatrics, Division of Pediatric Emergency Medicine, UPMC Children's Hospital of Pittsburgh, Pittsburgh, PA.
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14
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Audic B, Wodrich MD, Cramer N. Mild complexation protocol for chiral Cp xRh and Ir complexes suitable for in situ catalysis. Chem Sci 2018; 10:781-787. [PMID: 30774871 PMCID: PMC6346397 DOI: 10.1039/c8sc04385j] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Accepted: 10/29/2018] [Indexed: 12/25/2022] Open
Abstract
Mild complexations of chiral cyclopentadienes with rhodium(i) and iridium(i) precursors enable user-friendly in situ complex formation for catalytic applications.
A practical complexation method for chiral cyclopentadienyl (Cpx) iridium and rhodium complexes is described. The procedure uses the free CpxH with stable and commercially available rhodium(i) and iridium(i) salts without base or additive. The conditions are mild and do not require the exclusion of air and moisture. A salient feature is the suitability for in situ complexations enhancing the user-friendliness of Cpx ligands in asymmetric catalysis. DFT-calculations confirm an intramolecular proton abstraction pathway by either the bound acetate or methoxide. Furthermore, the superior facial selectivity of the proton abstraction step enabled the development of TMS-containing trisubstituted Cpx ligands which display improved enantioselectivities for the benchmarking dihydroisoquinolone synthesis.
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Affiliation(s)
- B Audic
- Laboratory of Asymmetric Catalysis and Synthesis , EPFL SB ISIC LCSA, BCH 4305 , CH-1015 Lausanne , Switzerland .
| | - M D Wodrich
- Laboratory for Computational Molecular Design , EPFL SB ISIC LCMD, BCH 5312 , CH-1015 Lausanne , Switzerland .
| | - N Cramer
- Laboratory of Asymmetric Catalysis and Synthesis , EPFL SB ISIC LCSA, BCH 4305 , CH-1015 Lausanne , Switzerland .
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15
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Cramer N, Fischer S, Hedtfeld S, Dorda M, Klockgether J, Wiehlmann L, Tümmler B. P038 Intraclonal competitive fitness of serial Pseudomonas aeruginosa isolates from cystic fibrosis lungs. J Cyst Fibros 2018. [DOI: 10.1016/s1569-1993(18)30335-7] [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: 12/01/2022]
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16
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Sun Y, Cramer N. Tailored trisubstituted chiral Cp x Rh III catalysts for kinetic resolutions of phosphinic amides. Chem Sci 2018; 9:2981-2985. [PMID: 29732080 PMCID: PMC5915793 DOI: 10.1039/c7sc05411d] [Citation(s) in RCA: 92] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Accepted: 02/03/2018] [Indexed: 12/13/2022] Open
Abstract
A trisubstituted chiral Cpx ligand family is introduced.
A trisubstituted chiral Cpx ligand family is introduced. Based on the disubstituted atropchiral Cpx ligand scaffold, the introduction of a bulky third substituent at the central position of the Cp ring leads to substantially increased selectivities for rhodium(iii)-catalyzed kinetic resolutions and allowed for s-factors of up to 50. Their superiority is demonstrated by kinetic resolutions of phosphinic amides providing access to compounds with stereogenic phosphorus(v) atoms. The unreacted acyclic phosphinic amide and the cyclized product are both obtained in good yields and enantioselectivities. The ligand synthesis capitalizes on a late stage modification and expands the accessible ligand Cpx ligand portfolio.
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Affiliation(s)
- Y Sun
- Laboratory of Asymmetric Catalysis and Synthesis , EPFL SB ISIC LCSA, BCH 4305 , CH-1015 , Lausanne , Switzerland .
| | - N Cramer
- Laboratory of Asymmetric Catalysis and Synthesis , EPFL SB ISIC LCSA, BCH 4305 , CH-1015 , Lausanne , Switzerland .
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17
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Smits G, Audic B, Wodrich MD, Corminboeuf C, Cramer N. A β-Carbon elimination strategy for convenient in situ access to cyclopentadienyl metal complexes. Chem Sci 2017; 8:7174-7179. [PMID: 29081949 PMCID: PMC5635420 DOI: 10.1039/c7sc02986a] [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] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Accepted: 08/24/2017] [Indexed: 01/07/2023] Open
Abstract
The electronic and steric properties of tailored cyclopentadienyl (Cp) ligands are powerful handles to modulate the catalytic properties of their metal complexes. This requires the individual preparation, purification and storage of each ligand/metal combination. Alternative, ideally in situ, complexation protocols would be of high utility. We disclose a new approach to access Cp metal complexes. Common metal precursors rapidly react with cyclopentadienyl carbinols via β-carbon eliminations to directly give the Cp-metal complexes. An advantage of this is the direct and flexible use of storable pre-ligands. No auxiliary base is required and the Cp complexes can be prepared in situ in the reaction vessel for subsequent catalytic transformations.
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Affiliation(s)
- G Smits
- Laboratory of Asymmetric Catalysis and Synthesis , EPFL SB ISIC LCSA , BCH 4305 , CH-1015 Lausanne , Switzerland .
| | - B Audic
- Laboratory of Asymmetric Catalysis and Synthesis , EPFL SB ISIC LCSA , BCH 4305 , CH-1015 Lausanne , Switzerland .
| | - M D Wodrich
- Laboratory for Computational Molecular Design , EPFL SB ISIC LCMD , BCH 5312 , CH-1015 Lausanne , Switzerland .
| | - C Corminboeuf
- Laboratory for Computational Molecular Design , EPFL SB ISIC LCMD , BCH 5312 , CH-1015 Lausanne , Switzerland .
| | - N Cramer
- Laboratory of Asymmetric Catalysis and Synthesis , EPFL SB ISIC LCSA , BCH 4305 , CH-1015 Lausanne , Switzerland .
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18
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Kossler D, Cramer N. Neutral chiral cyclopentadienyl Ru(ii)Cl catalysts enable enantioselective [2+2]-cycloadditions. Chem Sci 2017; 8:1862-1866. [PMID: 28553476 PMCID: PMC5430138 DOI: 10.1039/c6sc05092a] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Accepted: 12/23/2016] [Indexed: 01/19/2023] Open
Abstract
Cyclopentadienyl ruthenium(ii) complexes with a large number of available coordination sites are frequently used catalysts for a broad range of transformations. To be able to render these transformations enantioselective, we have designed a chiral neutral CpxRu(ii)Cl complex basing on an atropchiral cyclopentadienyl (Cpx) ligand which is accessed in a streamlined C-H functionalisation approach. The catalyst displays excellent levels of reactivity and enantioselectivity for enantioselective [2+2]-cycloadditions leading to strained chiral cyclobutenes, allowing for catalyst loadings as low as 1 mol%. A very strong counterion effect of a bound chloride anion transforms the corresponding unselective cationic complex into a highly enantioselective neutral version. Moreover, by adding norbornadiene at the end of the reaction the catalyst can be recovered and subsequently reused.
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Affiliation(s)
- D Kossler
- Laboratory of Asymmetric Catalysis and Synthesis , Institute of Chemical Sciences and Engineering , Ecole Polytechnique Fédérale de Lausanne , EPFL SB ISIC LCSA , BCH 4305 , CH-1015 Lausanne , Switzerland .
| | - N Cramer
- Laboratory of Asymmetric Catalysis and Synthesis , Institute of Chemical Sciences and Engineering , Ecole Polytechnique Fédérale de Lausanne , EPFL SB ISIC LCSA , BCH 4305 , CH-1015 Lausanne , Switzerland .
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Kourra CMBK, Cramer N. Converting disulfide bridges in native peptides to stable methylene thioacetals. Chem Sci 2016; 7:7007-7012. [PMID: 28451136 PMCID: PMC5355835 DOI: 10.1039/c6sc02285e] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Accepted: 07/24/2016] [Indexed: 12/26/2022] Open
Abstract
Disulfide bridges play a crucial role in defining and rigidifying the three-dimensional structure of peptides. However, disulfides are inherently unstable in reducing environments. Consequently, the development of strategies aiming to circumvent these deficiencies - ideally with little structural disturbance - are highly sought after. Herein, we report a simple protocol converting the disulfide bond of peptides into highly stable methylene thioacetal. The transformation occurs under mild, biocompatible conditions, enabling the conversion of unprotected native peptides into analogues with enhanced stability. The developed protocol is applicable to a range of peptides and selective in the presence of a multitude of potentially reactive functional groups. The thioacetal modification annihilates the reductive lability and increases the serum, pH and temperature stability of the important peptide hormone oxytocin. Moreover, it is shown that the biological activities for oxytocin are retained.
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Affiliation(s)
- C M B K Kourra
- Laboratory of Asymmetric Catalysis and Synthesis , Institute of Chemical Sciences and Engineering , Ecole Polytechnique Fédérale de Lausanne , EPFL SB ISIC LCSA , BCH 4305 , CH-1015 Lausanne , Switzerland .
| | - N Cramer
- Laboratory of Asymmetric Catalysis and Synthesis , Institute of Chemical Sciences and Engineering , Ecole Polytechnique Fédérale de Lausanne , EPFL SB ISIC LCSA , BCH 4305 , CH-1015 Lausanne , Switzerland .
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Abstract
The incidence of perinatal and neonatal Listeriosis is underestimated due undiagnosed stillbirths, misdiagnosis of NL and underreporting of single case reports. Recent outbreaks reinforce the need for better surveillance and targeted health education in certain population groups especially during pregnancy.
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Pedroni J, Saget T, Donets PA, Cramer N. Enantioselective palladium(0)-catalyzed intramolecular cyclopropane functionalization: access to dihydroquinolones, dihydroisoquinolones and the BMS-791325 ring system. Chem Sci 2015; 6:5164-5171. [PMID: 29142735 PMCID: PMC5667185 DOI: 10.1039/c5sc01909e] [Citation(s) in RCA: 87] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Accepted: 06/17/2015] [Indexed: 01/20/2023] Open
Abstract
Taddol-based phosphoramidite ligands enable enantioselective palladium(0)-catalyzed C-H arylation of cyclopropanes. The cyclized products are obtained in high yields and enantioselectivities. The reported method provides efficient access to a broad range of synthetically attractive cyclopropyl containing dihydroquinolones and dihydroisoquinolones as well as allows for an efficient enantioselective construction of the 7-membered ring of the cyclopropyl indolobenzazepine core of BMS-791325.
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Affiliation(s)
- J Pedroni
- Laboratory of Asymmetric Catalysis and Synthesis , Institute of Chemical Sciences and Engineering , Ecole Polytechnique Fédérale de Lausanne , EPFL SB ISIC LCSA, BCH 4305 , CH-1015 Lausanne , Switzerland .
| | - T Saget
- Laboratory of Asymmetric Catalysis and Synthesis , Institute of Chemical Sciences and Engineering , Ecole Polytechnique Fédérale de Lausanne , EPFL SB ISIC LCSA, BCH 4305 , CH-1015 Lausanne , Switzerland .
| | - P A Donets
- Laboratory of Asymmetric Catalysis and Synthesis , Institute of Chemical Sciences and Engineering , Ecole Polytechnique Fédérale de Lausanne , EPFL SB ISIC LCSA, BCH 4305 , CH-1015 Lausanne , Switzerland .
| | - N Cramer
- Laboratory of Asymmetric Catalysis and Synthesis , Institute of Chemical Sciences and Engineering , Ecole Polytechnique Fédérale de Lausanne , EPFL SB ISIC LCSA, BCH 4305 , CH-1015 Lausanne , Switzerland .
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Greipel L, Cramer N, Klockgether J, Dorda M, Mielke S, Chouvarine P, Wiehlmann L, Tümmler B. WS19.4 Molecular epidemiology of hot-spots of mutation in antimicrobial resistance loci of Pseudomonas aeruginosa isolates from cystic fibrosis airways. J Cyst Fibros 2015. [DOI: 10.1016/s1569-1993(15)30111-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Wiehlmann L, Cramer N, Sikorski J, Klockgether J, Davenport C, Winstanley C, Tümmler B. Population biology of Pseudomonas aeruginosa in chronic CF and COPD airway infections. Pneumologie 2014. [DOI: 10.1055/s-0034-1376789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Mainz J, Hentschel J, Schien C, Cramer N, Pfister W, Beck J, Tümmler B. Sinonasal persistence of Pseudomonas aeruginosa after lung transplantation. J Cyst Fibros 2012; 11:158-61. [DOI: 10.1016/j.jcf.2011.10.009] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2011] [Revised: 10/27/2011] [Accepted: 10/28/2011] [Indexed: 10/14/2022]
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Mainz JG, Naehrlich L, Schien M, Käding M, Schiller I, Mayr S, Schneider G, Wiedemann B, Wiehlmann L, Cramer N, Pfister W, Kahl BC, Beck JF, Tümmler B. Concordant genotype of upper and lower airways P aeruginosa and S aureus isolates in cystic fibrosis. Thorax 2009; 64:535-40. [PMID: 19282318 DOI: 10.1136/thx.2008.104711] [Citation(s) in RCA: 146] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
RATIONALE Lower airway (LAW) infection with Pseudomonas aeruginosa and Staphylococcus aureus is the leading cause of morbidity in cystic fibrosis (CF). The upper airways (UAW) were shown to be a gateway for acquisition of opportunistic bacteria and to act as a reservoir for them. Therefore, tools for UAW assessment within CF routine care require evaluation. OBJECTIVES The aims of the study were non-invasive assessment of UAW and LAW microbial colonisation, and genotyping of P aeruginosa and S aureus strains from both segments. METHODS 182 patients with CF were evaluated (age 0.4-68 years, median 17 years). LAW specimens were preferably sampled as expectorated sputum and UAW specimens by nasal lavage. P aeruginosa and S aureus isolates were typed by informative single nucleotide polymorphisms (SNPs) or by spa typing, respectively. RESULTS Of the typable S aureus and P aeruginosa isolates from concomitant UAW- and LAW-positive specimens, 31 of 36 patients were carrying identical S aureus spa types and 23 of 24 patients identical P aeruginosa SNP genotypes in both compartments. Detection of S aureus or P aeruginosa in LAW specimens was associated with a 15- or 88-fold higher likelihood also to identify S aureus or P aeruginosa in a UAW specimen from the same patient. CONCLUSIONS The presence of identical genotypes in UAW and LAW suggests that the UAW play a role as a reservoir of S aureus and P aeruginosa in CF. Nasal lavage appears to be suitable for non-invasive UAW sampling, but further longitudinal analyses and comparison with invasive methods are required. While UAW bacterial colonisation is typically not assessed in regular CF care, the data challenge the need to discuss diagnostic and therapeutic standards for this airway compartment. TRIAL REGISTRATION NUMBER NCT00266474.
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Affiliation(s)
- J G Mainz
- Department of Pediatrics, University of Jena, Cystic Fibrosis Center, Jena, Germany.
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Cramer N, Wiehlmann L, Wagner G, Tümmler B. Molekulare Epidemiologie von Langzeitverläufen einer Pseudomonas aeruginosa Infektion bei Patienten mit cystischer Fibrose. Pneumologie 2007. [DOI: 10.1055/s-2007-967246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Wiehlmann L, Cramer N, Köhler T, Morales G, Wagner G, Siebert B, Delden CV, Tümmler B. Entwicklung eines DNA-Chips zur schnellen Typisierung von Pseudomonas aeruginosa. Pneumologie 2007. [DOI: 10.1055/s-2007-967245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Wiehlmann L, Cramer N, Köhler T, Morales G, Wagner G, Siebert B, van Delden C, Tummler B. 139 DNA-chip based high throughput analysis of the population structure of Pseudomonas aeruginosa. J Cyst Fibros 2006. [DOI: 10.1016/s1569-1993(06)80123-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Cramer N, Wiehlmann L, Wagner G, Tümmler B. 129 Molecular epidemiology of the longitudinal course of the Pseudomonas aeruginosa infection in Cystic Fibrosis. J Cyst Fibros 2006. [DOI: 10.1016/s1569-1993(06)80113-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Cramer N, Crombie IK. Five-year age-specific incidence rates. II: The accuracy of calculations of expected number of tumours. J Epidemiol Community Health 1981; 35:146-9. [PMID: 7299340 PMCID: PMC1052142 DOI: 10.1136/jech.35.2.146] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Five-year age-specific incidence rates were shown to produce small but systematic errors in the calculation of the expected number of tumours in a hypothetical but realistic study population. Underestimates occurred at younger ages (under 55) and overestimates at older ages, with a small overestimate (0.22%) overall. Larger errors (up to 12%) were obtained when there was a rapid change in the single-year age structure of the study population. Interpolation between five-year rates will normally produce an inaccurate set of one-year rates. It is shown, with the example of a logarithmic interpolation, that these rates tend to produce errors of similar size to the five-year rates but with a small underestimate overall (0.37%). However, the interpolated rates produced the smaller errors (up to 1%) when the study population age structure undergoes rapid change. A method is suggested for partially correcting the error in the interpolated rates.
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Abstract
The effect of population structure on five-year age-specific incidence rates was investigated using the one-year population data from life tables and a theoretical age incidence curve of the form: I = btk - where I is the incidence at age t, and b and k are constants. The five-year incidence rates differed systematically from the one-year rates of the central year of the five-year period. This difference depended on the change with age of both the population size and the incidence rate. Thus at ages 20-24 the five-year rate overestimates the mid-period one-year rate by about 4%, but the overestimate progressively decreases to become an underestimate of 0.5% at ages 75-79. In consequence the one-year and five-year rates produce fitted age incidence curves with different slopes; the value of k in the incidence equation is about 0.7% greater for the one-year rates. The population structures of developed and underdeveloped countries are markedly different and these were found to affect the five-year incidence rates, but never by more than 0.5%. The effect of the irregularities in one-year age structure of real populations on the observed five-year rates is also small, of the order of 0.5%. However, when incidence rates are calculated by recording tumours over several calendar years, these irregularities can create difficulties for the estimation of the appropriate denominator population. The use of the census population, even that of the central year of the observation period, can be in error by over 2%. A good method is to calculate the mean annual population of the observation period, estimating the intercensal year populations by interpolation between flanking censuses.
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