43 results on '"Onwubiko C"'
Search Results
2. Carica papaya leaf extract ameliorates catalepsy and depression but not convulsion in mice
- Author
-
Iniaghe, L. O., Okpakpor, E. E., Edeko, E. E., Egwenu, C. K., and Onwubiko, C.
- Subjects
C. papaya, catalepsy, seizure, depression, model - Abstract
Carica papaya is a common herbaceous plant consumed as food and used as a therapeutic agent. This study examined the effect of the aqueous extract of C. papaya leaves on catalepsy, depression and convulsion. Phytochemical screening and determination of the mean lethal dose were carried out. Haloperidol-induced catalepsy, the forced swim test, the tail suspension, pentylene tetrazole (PTZ)-induced seizures and maximal electroshock (MES) tests were used to evaluate the effects of C. papaya on catalepsy, depression and convulsion at 3 dose levels -100, 200 and 400 mg/kg. Carbohydrates, flavonoids, saponins, steroids and tannins were detected and the mean lethal dose was determined to be greater than 5000 mg/kg. The extract significantly (p
- Published
- 2022
3. An Evolutionary Approach in Threats Detection for Distributed Security Defence Systems
- Author
-
Onwubiko, C., Lenaghan, A. P., Hutchison, David, editor, Kanade, Takeo, editor, Kittler, Josef, editor, Kleinberg, Jon M., editor, Mattern, Friedemann, editor, Mitchell, John C., editor, Naor, Moni, editor, Nierstrasz, Oscar, editor, Pandu Rangan, C., editor, Steffen, Bernhard, editor, Sudan, Madhu, editor, Terzopoulos, Demetri, editor, Tygar, Dough, editor, Vardi, Moshe Y., editor, Weikum, Gerhard, editor, Mehrotra, Sharad, editor, Zeng, Daniel D., editor, Chen, Hsinchun, editor, Thuraisingham, Bhavani, editor, and Wang, Fei-Yue, editor
- Published
- 2006
- Full Text
- View/download PDF
4. Heavy Metals Pollution Index in African River Prawn (Macro brachium Vollenhoven Ii) collected from Calabar River, Nigeria
- Author
-
Onwubiko, C. C., primary, Onuoha, E. M., additional, and Anukwa, F. A., additional
- Published
- 2020
- Full Text
- View/download PDF
5. An Evolutionary Approach in Threats Detection for Distributed Security Defence Systems
- Author
-
Onwubiko, C., primary and Lenaghan, A. P., additional
- Published
- 2006
- Full Text
- View/download PDF
6. The prevalence of incidental findings on computed tomography of the abdomen/pelvis in pediatric trauma patients
- Author
-
Onwubiko, C., primary and Mooney, D. P., additional
- Published
- 2017
- Full Text
- View/download PDF
7. Increased Subcutaneous Abdominal Fat Is Associated With a Higher Residual Cancer Burden in Breast Cancer Patients on Neoadjuvant Chemotherapy
- Author
-
Zhang, H, Patterson, S, Tanner, S, Brown, A, Onwubiko, C, Griswold, M, Miele, Luca, and Smith, A
- Subjects
N/A ,Settore MED/12 - GASTROENTEROLOGIA - Published
- 2012
8. Managing Security Threats and Vulnerabilities for Small to Medium Enterprises
- Author
-
Onwubiko, C., primary and Lenaghan, A. P., additional
- Published
- 2007
- Full Text
- View/download PDF
9. An integrated security framework for assisting in the defence of computer networks
- Author
-
Onwubiko, C., primary, Lenaghan, A.P., additional, and Hebbes, L., additional
- Published
- 2006
- Full Text
- View/download PDF
10. An Improved Worm Mitigation Model for Evaluating the Spread of Aggressive Network Worms
- Author
-
Onwubiko, C., primary, Lenaghan, A.P., additional, and Hebbes, L., additional
- Published
- 2005
- Full Text
- View/download PDF
11. Functional requirements of situational awareness in computer network security.
- Author
-
Onwubiko, C.
- Published
- 2009
- Full Text
- View/download PDF
12. Security Spaces for Protecting Users of Wireless Public Hotspots.
- Author
-
Lenaghan, A., Onwubiko, C., Hebbes, L., and Malyan, R.
- Published
- 2005
- Full Text
- View/download PDF
13. Design of a framed building using a probabilistic fault tree analysis method
- Author
-
Chen, F., primary, Onwubiko, C., additional, and Onyebueke, L., additional
- Published
- 1996
- Full Text
- View/download PDF
14. Design of a multistory framed building using system reliability method
- Author
-
Chen, F, primary, Onwubiko, C, additional, and Onyebueke, L, additional
- Published
- 1995
- Full Text
- View/download PDF
15. Impact of the Internet on Research Effort of Academics at Abia State University, Uturu, (ABSU).
- Author
-
Onwubiko, C. P. C.
- Subjects
- *
ACQUISITION of data , *CYBERCAFES , *LEARNING , *MOBILE computing - Abstract
This paper is on the impact of the Internet on the research effort of academics at Abia State University Uturu. The Internet has become an invaluable tool for teaching, learning and research. The benefits are so enormous that there is no sphere of life without the Internet application. This is certainly true for tertiary institutions. Premised on this consciousness, the descriptive survey research method was adopted in carrying out the study, with the questionnaire as the sole instrument for data collection. The study was guided by six objectives. The findings of the study revealed that there is no felt need for the use of the Internet in research, Internet laboratories exist within and around the campus, and the non-accessibility of Internet laboratories to lecturers. Other findings are that the lecturers rarely go to cyber-cafe in town to seek information, the Internet has no impact on the research effort of lecturers, and the use of the Internet is inhibited by a lot of problems. The study recommends that the lecturers should develop personal interest in the use of the Internet, Internet laboratories on campus should be scheduled and made accessible to lecturers and they should avail themselves of available Internet services and train themselves on computer and Internet literacy. The study further recommends that lecturers should regularly go to cybercafés for ICT services and refresh newly acquired ICT knowledge, and the integration of ICT in teaching, learning and research. Furthermore all other inhibitors to the use of the Internet should be eliminated. The study contends that the strategic and holistic implementation of the recommendations would bring about the desired impact and contributions of the Internet to the quality of research of ABSU lecturers studied and those of them in other institutions with similar problematic features. [ABSTRACT FROM AUTHOR]
- Published
- 2012
16. An Evolutionary Approach in Threats Detection for Distributed Security Defence Systems.
- Author
-
Mehrotra, Sharad, Zeng, Daniel D., Chen, Hsinchun, Thuraisingham, Bhavani, Wang, Fei-Yue, Onwubiko, C., and Lenaghan, A.P.
- Abstract
A security defence framework is proposed that offers capabilities for distributed sensing of security threats, centralised analysis and coordinated response. The centralised analysis component of the framework uses graph and evolutionary computing techniques to analyse distributed threats perceived in the network. Keywords: security defence framework, genetic algorithms, security threats. [ABSTRACT FROM AUTHOR]
- Published
- 2006
- Full Text
- View/download PDF
17. Piston Rod Design Using Johnson’s Method of Optimum Design
- Author
-
Onwubiko, C.
- Abstract
Many of the available algorithms for solving the problems of nonlinear optimization have failed to yield results. This may be as a result of searching for solutions in an infeasible region or because the problem is ill-defined. In any case, there is no way for the designer to know that any of these situations exist ahead of time. However, Johnson’s method of optimum design is one algorithm that is capable of giving insight to the designer when a feasible solution may exist. This paper applies this method to the design of a piston rod. It is also demonstrated that using this method the designer can easily consider many types of materials in the design process without undue waste of time.
- Published
- 1988
- Full Text
- View/download PDF
18. Surface influences on the characteristic performance of the salt gradient solar pond--an experimental study
- Author
-
Onwubiko, C
- Published
- 1982
19. Evaluation of a National Sample of 16,671 Pediatric Burn Admissions: Identifying Predictors of Non-accidental Pediatric Burns.
- Author
-
Koenig SM, Mathis MS, Onwubiko C, Chen MK, Beierle EA, and Russell RT
- Abstract
Background: Burn injuries remain one of the leading causes of injury and death in children. Studies have demonstrated a higher mortality for pediatric burns associated with non-accidental injury. Using data from a burn registry, our study aimed to discern potential factors associated with non-accidental burn injuries., Methods: We utilized the American Burn Association database from 2016 to 2018, which collects data from over one hundred burn centers across the United States, to evaluate a large pediatric burn population. Patients aged ≤14 years were analyzed. The population was then divided into suspected non-accidental versus accidental burn injuries. A multivariable logistic regression model was utilized to evaluate for predictors of burn injuries. Additional models were used to assess the relationship between suspected non-accidental burn injury and mortality, intensive care unit (ICU) stay, and hospital length of stay., Results: 16,671 pediatric patients were included. Of those, 1228 (7.4%) patients suffered non-accidental burn injury. A majority of children who sustained non-accidental burn injury were younger, non-white, and sustained scald burns. The regression model demonstrated predictors for non-accidental burn injuries included younger age, Black race, chemical/corrosion burns, government insurance, and increased total body surface area (TBSA) burn. Overall mortality for the population was 0.5%., Conclusion: This evaluation of a national burn registry reveals differences in pediatric patients sustaining non-accidental burns compared to accidental burns. The findings in this study identify pediatric populations at risk for suspected non-accidental burn injuries which may assist in preparing the families for expectations after admission for a burn injury., Level of Evidence: III., Competing Interests: Conflicts of interest None., (Copyright © 2024 Elsevier Inc. All rights reserved.)
- Published
- 2024
- Full Text
- View/download PDF
20. Vascular Access for Renal Replacement Therapy in Neonates and Infants: A Single Center Experience.
- Author
-
Koenig SM, Oslock WM, Short K, Potts J, Askenazi D, Onwubiko C, Russell RT, and Mortellaro VE
- Abstract
Introduction: Neonatal renal replacement therapy (RRT) is a treatment modality used for severe kidney failure. Historically, its use has been limited in small infants due to circuits with large extra-corporeal volumes that require large double lumen vascular catheters. We sought to review our institution's experience with vascular access and overall survival in infants who receive RRT., Methods: A retrospective chart review of infants less than 5 kg (kg) was performed at our free-standing children's hospital from January 2016 to July 2023. We assessed the number of catheters used per patient, location of catheter placements, size of catheter, duration of treatment, reasons for line removal, and mortality., Results: A total of 93 neonatal patients were identified who underwent RRT. Thirty-two patients (34.4%) required more than one catheter, with a total of 145 catheters placed for this cohort. The median (IQR) weight at insertion was 3.3 kg (2.7-4.0). The most common location for placement was the right internal jugular vein (n = 114, 78.6%). Patients required catheters for RRT for a median (IQR) of 16 days (7-39). Six patients underwent catheter placement at a weight of less than 2 kg. Nineteen total patients went on to peritoneal dialysis (20.4%). Fifty-three patients died during their admission (57.0%)., Conclusion: To our knowledge this is the largest review of catheter use for RRT in infants within an intensive care unit and it reveals the success in treating renal failure in even the smallest infants., Level of Evidence: IV, Treatment Study., Competing Interests: Conflicts of interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)
- Published
- 2024
- Full Text
- View/download PDF
21. Pediatric Burn Injuries: Risk Factors for Increased Mortality.
- Author
-
Koenig SM, Deng L, Onwubiko C, Beierle EA, and Russell RT
- Subjects
- Humans, Child, Child, Preschool, Risk Factors, Female, Male, Infant, Adolescent, Retrospective Studies, United States epidemiology, Databases, Factual statistics & numerical data, Infant, Newborn, Age Factors, Burns mortality
- Abstract
Introduction: Burn injuries are among the top ten leading causes of unintentional death in pediatric patients and are encountered by pediatric surgeons in all practice settings. There is a lack of literature evaluating mortality in pediatric burn injuries in regard to nonaccidental burns and potential disparities. Our study aims to determine the risk factors associated with mortality in pediatric burn injuries and highlight the characteristics of this patient population., Methods: We utilized the Trauma Quality Improvement Program database from 2017 to 2019 to identify primary burn injuries in children ≤14 y old. Physical abuse descriptors were used to identify patients with suspected nonaccidental injuries. Further demographics, including age, race, ethnicity, and insurance type, were evaluated. Descriptive statistics were generated and a multivariable logistic regression analysis was utilized to evaluate risk factors for mortality., Results: 13,472 pediatric burn patients (≤14 y old) were identified. The overall mortality was low (<1%). Children with burns to multiple body regions had the highest independent risk of mortality in this cohort. All older age groups had an independent risk of mortality compared to the youngest patients, but those from ages 5 to <10 y old had the highest risk of mortality (OR = 11.40; 95% confidence interval: 4.41-29.43, P < 0.001). Black children had a significantly higher mortality compared to White children. Nonaccidental burns carried a mortality that was twice that of accidental burns. Government insurance type was the primary insurance type for a majority of patients who died., Conclusions: Risk factors for mortality in pediatric burn include Black race, multiple affected body regions, and nonaccidental burns. This study identified an increased mortality risk in the older age groups in contrast to previous studies that showed increased mortality in younger patients suffering from burn injuries., (Published by Elsevier Inc.)
- Published
- 2024
- Full Text
- View/download PDF
22. Portal Vein Thrombosis Following Splenectomy in Children: Is There a Higher Rate When Using Single-Incision Laparoscopy?
- Author
-
Esparaz JR, Onwubiko C, and Mortellaro VE
- Subjects
- Adolescent, Cause of Death, Child, Child, Preschool, Conversion to Open Surgery statistics & numerical data, Female, Humans, Laparoscopy methods, Male, Postoperative Complications diagnostic imaging, Postoperative Complications epidemiology, Retrospective Studies, Splenectomy methods, Venous Thrombosis diagnostic imaging, Venous Thrombosis epidemiology, Laparoscopy adverse effects, Portal Vein diagnostic imaging, Postoperative Complications etiology, Splenectomy adverse effects, Venous Thrombosis etiology
- Abstract
Background: Portal vein thrombosis can be a life-threatening complication associated with a splenectomy. Laparoscopic splenectomy has been suggested to cause an increased rate of portal vein thrombosis. Our study evaluated the rate of portal vein thrombosis in pediatric patients who underwent a splenectomy via single-site laparoscopy., Methods: A retrospective chart review was performed for all patients undergoing laparoscopic splenectomy from November 2012 to July 2019. Demographic data, operative details, postoperative imaging, and patient outcomes were obtained for analysis. Patients were contacted to determine if they had any complications for which they sought medical care elsewhere., Results: There were 78 pediatric patients who underwent laparoscopic splenectomy over the 7-year period. The most common indication was sickle cell disease (70.5%). Single-incision laparoscopy was performed in 61.5% of the cases. Eight were converted to open. Eleven patients (14.1%) had a laparoscopic cholecystectomy performed during the same operation. The overall complication rate was 8.9%. A quarter of our patients had imaging within 1 year of surgery; no portal vein thrombosis was identified. In addition, over half of the patients were recontacted for follow-up questioning. None of the patients surveyed sought medical care elsewhere for a surgery-related complication or sequela of a portal vein thrombus., Discussion: Single-incision laparoscopic splenectomy is a safe approach in children. Using the single-site platform allows the flexibility to perform additional operations, such as cholecystectomy, without the placement of additional ports. This analysis shows that patients undergoing single-incision laparoscopic splenectomy do not have a higher rate for portal vein thrombosis.
- Published
- 2022
- Full Text
- View/download PDF
23. Small tunneled central venous catheters as an alternative to a standard hemodialysis catheter in neonatal patients.
- Author
-
Onwubiko C, Askenazi D, Ingram D, Griffin R, Russell RT, and Mortellaro VE
- Subjects
- Catheters, Indwelling adverse effects, Humans, Infant, Newborn, Renal Dialysis, Retrospective Studies, Treatment Outcome, Catheterization, Central Venous adverse effects, Central Venous Catheters adverse effects
- Abstract
Background/purpose: Continuous renal replacement therapy (CRRT) is difficult in neonates for several reasons, including problems with catheter placement and maintenance. We sought to compare outcomes between standard hemodialysis catheters (HDC) and 6Fr-tunneled central venous catheters (TC-6Fr)., Methods: We evaluated neonates who received CRRT from December 2013 - January 2018. All patients received CRRT with the Aquadex (Baxter Corporation, Minneapolis, Minnesota) circuit. Data regarding patient demographics, CRRT indication, catheter days, reason for removal, and catheter-specific complications were analyzed., Results: Forty-six catheters were placed in 26 neonates; nine of these were 6Fr-tunneled catheters. The median age and mean weight at CRRT initiation was 9.5 days (IQR 4-31) and 3.5 kg (+/- 0.6 kg), respectively. TC-6Fr lasted longer (median of 28 days vs 10 days, p = 0.02), required fewer revisions (0 vs 0.16/10 catheter days) and were less commonly removed due to bleeding complications (0% vs 10.8%), occlusion (11.1% vs 18.9%), or malposition (0% vs 8.1%); none of these differences were statistically significant. TC-6Fr were associated with higher infection rates (33.3% vs 0%, p = 0.01) than HDC., Conclusions: TC-6Fr use resulted in less need for catheter revisions and provided longer-lasting vascular access, which may influence infection rates. This catheter provides neonates in need of CRRT more reliable vascular access., Level of Evidence: III., Competing Interests: Declaration of Competing Interest All authors declare no real or perceived conflicts of interest that could affect the study design, collection, analysis and interpretation of data, writing of the report, or the decision to submit for publication. For full disclosure, we provide here an additional list of other author's commitments and funding sources that are not directly related to this study: David J Askenazi serves on the speaker board for Baxter (Baxter, USA), and the Acute Kidney Injury (AKI) Foundation (Cincinnati, OH, USA); he also receives grant funding for studies not related to this manuscript from Octapharma AG (Switzerland), CHF solutions, Baxter and the National Institutes of Health - National Institutes of Diabetes and Digestive and Kidney Diseases (NIHNIDDK, R01 DK103608) and consults for CHF solutions. None of these commitments are related to the scope of the current study., (Copyright © 2021. Published by Elsevier Inc.)
- Published
- 2021
- Full Text
- View/download PDF
24. Laparoscopic Treatment of Slipping Rib Syndrome in Pediatric Patients.
- Author
-
Squillaro AI, Sanders K, Onwubiko C, Chang CJ, and Kim S
- Subjects
- Abdominal Pain etiology, Adolescent, Chest Pain etiology, Child, Chronic Pain surgery, Cicatrix complications, Female, Humans, Length of Stay, Male, Minimally Invasive Surgical Procedures, Orthopedic Procedures, Pain Management, Postoperative Complications, Retrospective Studies, Syndrome, Thorax, Treatment Outcome, Abdominal Pain surgery, Cartilage surgery, Laparoscopy methods, Ribs surgery
- Abstract
Background: Slipping rib syndrome (SRS) is an often unrecognized cause of lower chest and upper abdominal pain in children and adolescents. Surgical resection of the cartilaginous portions of the slipping rib often provides permanent pain relief, with the standard surgical approach being an open resection. A minimally invasive approach has not been reported previously; we report a novel laparoscopic technique for the treatment of SRS with satisfactory results. Materials and Methods: A retrospective review of all consecutive pediatric patients who underwent laparoscopic cartilage resection during the year 2019 and open cartilage resection during the year 2018 was included. Following data were recorded: age of patients, length of symptoms, length of procedure, length of cartilage resection, length of stay, resolution of pain, cosmetic acceptability, and postoperative complications. Results: Four patients underwent laparoscopic slipping rib resection without complication during the year 2019. The mean age of symptom onset was 15 (range 14-16) years old, mean length of symptoms was 1.4 (0.5-2.0) years, and mean age at operation was 16.5 (16-18) years old. The average length of the procedure was 72.8 (55-102) minutes, and mean length of cartilage removed was 2.3 (1.9-3.0) cm. Three patients underwent standard open operation during the year 2018. All patients reported complete resolution of their chronic pain at their 6-month follow-up visit. Conclusions: Laparoscopic technique can be used to treat SRS. All patients reported high satisfaction from resolution of chronic pain and the cosmetic appearance of their surgical scars.
- Published
- 2020
- Full Text
- View/download PDF
25. Does the incidence of thoracic aortic injury warrant the routine use of chest computed tomography in children?
- Author
-
Arbuthnot M, Onwubiko C, Osborne M, and Mooney DP
- Subjects
- Accidents, Traffic statistics & numerical data, Adolescent, Aortic Diseases epidemiology, Aortic Diseases mortality, Case-Control Studies, Child, Child, Preschool, Female, Health Status Indicators, Humans, Incidence, Male, Neoplasms, Radiation-Induced epidemiology, Thoracic Injuries epidemiology, Thoracic Injuries mortality, Thorax diagnostic imaging, Thorax pathology, Tomography, X-Ray Computed standards, United States epidemiology, Aorta, Thoracic diagnostic imaging, Aorta, Thoracic injuries, Aortic Diseases diagnostic imaging, Thoracic Injuries complications, Tomography, X-Ray Computed adverse effects
- Abstract
Background: Thoracic aortic injury is a potentially life-threatening injury associated with rapid deceleration mechanisms. Diagnosis is made by chest computed tomography (CT), which is associated with a risk of radiation-induced malignancy. We sought to determine the incidence of aortic injuries in the pediatric population to weigh against the risk of CT imaging., Methods: The Pediatric Health Information Systems was queried for children ≤18 years with discharge diagnosis code of thoracic aortic injury (901.0) between December 2004 and 2014. Data abstracted included patient age, gender, diagnosis and procedure codes, and discharge disposition, where available. We also queried for imaging codes to determine what type of chest imaging the child received., Results: Between December 2004 and 2014, 311,850 children were admitted to Pediatric Health Information Systems hospitals with traumatic injury. Of these patients, 46 (0.015%) were coded with a thoracic aortic injury and an accompanying E-code. Twenty-seven patients (58.7%) were male, and the median age was 13 years. The most common mechanism of injury was motor vehicle collision (63%, n = 29). Eighteen hospitals (41.9%) had no patients with a thoracic aortic injury in the 10-year period. In children with a thoracic aortic injury, the mortality rate was 11% (n = 5) and 22 (47.8%) underwent a chest CT during their hospitalization. Forty percent (124,909) of all trauma patients underwent chest CT, with a positive rate for aortic injury of 1.8/10,000. The reported estimated cancer risk from a chest CT scan is 25/10,000 for girls and 7.5/10, 000 in boys, greater than the positive CT rate., Conclusion: Thoracic aortic injuries are rare in children in the United States. The risk of cancer associated with screening chest CT is greater than the likelihood of identifying an aortic injury. Therefore, screening chest CT scans are unwarranted in injured children., Level of Evidence: Therapeutic/Care Management, level IV.
- Published
- 2019
- Full Text
- View/download PDF
26. Gastrosplenic Fistula without Malignancy Management in a 16-Year-Old Boy.
- Author
-
Malik A, Onwubiko C, Chen M, Radulescu A, Galloway D, and Martin C
- Abstract
Gastrosplenic fistula is a very rare entity, most commonly occurring as a distinctive complication of splenic or gastric malignancies, most notably diffuse large B cell lymphoma (DLBCL). Benign gastric ulcer, splenic abscess, and Crohn's disease have also been reported as possible causes. We report a nonmalignant case of 16-year-old male with a gastrosplenic fistula of unclear etiology. The fistulous tract was confirmed by an upper endoscopy and an upper gastrointestinal series. Subsequently, it was surgically managed with a subtotal gastrectomy with "Roux-en-Y" reconstruction and a feeding jejunostomy., Competing Interests: Conflict of Interest None.
- Published
- 2019
- Full Text
- View/download PDF
27. Improving imaging strategies in pediatric appendicitis: a quality improvement initiative.
- Author
-
Schoel L, Maizlin II, Koppelmann T, Onwubiko C, Shroyer M, Douglas A, and Russell RT
- Subjects
- Appendicitis surgery, Child, Critical Pathways organization & administration, Emergency Service, Hospital organization & administration, Emergency Service, Hospital statistics & numerical data, Evidence-Based Medicine organization & administration, Evidence-Based Medicine statistics & numerical data, Female, Health Plan Implementation organization & administration, Health Plan Implementation statistics & numerical data, Humans, Interdisciplinary Communication, Length of Stay statistics & numerical data, Male, Postoperative Complications epidemiology, Postoperative Complications etiology, Preoperative Care statistics & numerical data, Retrospective Studies, Tomography, X-Ray Computed economics, Tomography, X-Ray Computed statistics & numerical data, Treatment Outcome, Ultrasonography economics, Ultrasonography statistics & numerical data, Appendectomy adverse effects, Appendicitis diagnostic imaging, Preoperative Care economics, Procedures and Techniques Utilization organization & administration, Quality Improvement
- Abstract
Background: Data from the American College of Surgeons National Surgical Quality Improvement Program identified our hospital as an outlier for preoperative computed tomography (CT) use in the diagnosis of acute appendicitis in children. We performed a quality improvement project to reduce this utilization in favor of ultrasound-based diagnoses (ultrasonography [US]) through creation and implementation of an evidence-based appendicitis algorithm., Methods: Over a 2-y period (1 y preceding and 1 y following institution of the algorithm), the clinical information of all pediatric patients operated on for suspicion of acute appendicitis following imaging studies in our institution was collated. Basic characteristics were compared before and after protocol implementation using the chi-square test for categorical variables and the nonparametric, independent sample test of medians for numerical variables. Imaging modalities used and clinical outcomes were compared using chi-square analysis., Results: A total of 227 patients (117 preprotocol and 110 postprotocol implementation) were evaluated in our emergency department and operated on for suspicion of acute appendicitis. There were no differences in age, sex, race, or body mass index between the two periods. There were also no differences in length of stay (P = 0.27), acute and perforated appendicitis rates (P = 0.59), negative appendectomy rates (P = 0.40), or postoperative complications (P = 0.19). There was a significant reduction in the utilization of CT, from 65.8% to 22.0%, with a concurrent increase in the utilization of US (P < 0.001)., Conclusions: With the implementation of a standardized, multidisciplinary algorithm, CT utilization was decreased and concurrently US utilization was increased without sacrificing diagnostic accuracy or patient outcomes., (Copyright © 2018 Elsevier Inc. All rights reserved.)
- Published
- 2018
- Full Text
- View/download PDF
28. Pediatric Patients with Small-Cell Carcinoma of the Ovary Have Similar Survival to Adults: A Review of the National Cancer Database.
- Author
-
Maizlin II, Nice TR, Onwubiko C, Goldfarb M, Gow KW, Langer M, Doski JJ, Goldin A, and Beierle EA
- Subjects
- Adult, Carcinoma, Small Cell therapy, Child, Combined Modality Therapy, Databases, Factual, Female, Humans, Ovarian Neoplasms therapy, Prognosis, Survival Rate trends, United States epidemiology, Carcinoma, Small Cell mortality, Ovarian Neoplasms mortality, Population Surveillance methods, Registries
- Published
- 2018
29. Systemic Thrombolysis of an Occlusive Aortic Thrombus in a Neonate on Extracorporeal Membrane Oxygenation.
- Author
-
Onwubiko C, Koppelmann T, Waters AM, Radulescu A, Chen MK, Martin CA, Anderson SA, Russell RT, Mortellaro VE, Rogers DA, and Beierle EA
- Subjects
- Aortic Diseases diagnosis, Aortic Diseases etiology, Fibrinolytic Agents therapeutic use, Humans, Infant, Newborn, Male, Thrombosis diagnosis, Thrombosis etiology, Ultrasonography, Aorta, Abdominal, Aortic Diseases drug therapy, Extracorporeal Membrane Oxygenation adverse effects, Respiratory Insufficiency therapy, Thrombolytic Therapy methods, Thrombosis drug therapy, Tissue Plasminogen Activator therapeutic use
- Published
- 2018
30. Contrast enhanced ultrasound for the evaluation of blunt pediatric abdominal trauma.
- Author
-
Armstrong LB, Mooney DP, Paltiel H, Barnewolt C, Dionigi B, Arbuthnot M, Onwubiko C, Connolly SA, Jarrett DY, and Zalieckas JM
- Subjects
- Adolescent, Child, Contrast Media, Female, Humans, Kidney injuries, Liver injuries, Male, Prospective Studies, Sensitivity and Specificity, Spleen injuries, Tomography, X-Ray Computed, Abdominal Injuries diagnostic imaging, Ultrasonography methods, Wounds, Nonpenetrating diagnostic imaging
- Abstract
Introduction: Blunt abdominal trauma is a common problem in children. Computed tomography (CT) is the gold standard for imaging in pediatric blunt abdominal trauma, however up to 50% of CTs are normal and CT carries a risk of radiation-induced cancer. Contrast enhanced ultrasound (CEUS) may allow accurate detection of abdominal organ injuries while eliminating exposure to ionizing radiation., Methods: Children aged 7-18years with a CT-diagnosed abdominal solid organ injury underwent grayscale/power Doppler ultrasound (conventional US) and CEUS within 48h of injury. Two blinded radiologists underwent a brief training in CEUS and then interpreted the CEUS images without patient interaction. Conventional US and CEUS images were compared to CT for the presence of injury and, if present, the injury grade. Patients were monitored for contrast-related adverse reactions., Results: Twenty one injured organs were identified by CT in eighteen children. Conventional US identified the injuries with a sensitivity of 45.2%, which increased to 85.7% using CEUS. The specificity of conventional US was 96.4% and increased to 98.6% using CEUS. The positive predictive value increased from 79.2% to 94.7% and the negative predictive value from 85.3% to 95.8%. Two patients had injuries that were missed by both radiologists on CEUS. In a 100kg, 17year old female, a grade III liver injury was not seen by either radiologist on CEUS. Her accompanying grade I kidney injury was not seen by one of the radiologist on CEUS. The second patient, a 16year old female, had a grade III splenic injury that was missed by both radiologists on CEUS. She also had an adjacent grade II kidney injury that was seen by both. Injuries, when noted, were graded within 1 grade of CT 33/35 times with CEUS. There were no adverse reactions to the contrast., Conclusion: CEUS is a promising imaging modality that can detect most abdominal solid organ injuries in children while eliminating exposure to ionizing radiation. A multicenter trial is warranted before widespread use can be recommended., Level of Evidence: Level II; Diagnostic Prospective Study., (Copyright © 2017 Elsevier Inc. All rights reserved.)
- Published
- 2018
- Full Text
- View/download PDF
31. Acute procedural interventions after pediatric blunt abdominal trauma: A prospective multicenter evaluation.
- Author
-
Arbra CA, Vogel AM, Zhang J, Mauldin PD, Huang EY, Savoie KB, Santore MT, Tsao K, Ostovar-Kermani TG, Falcone RA, Dassinger MS, Recicar J, Haynes JH, Blakely ML, Russell RT, Naik-Mathuria BJ, St Peter SD, Mooney DP, Onwubiko C, Upperman JS, and Streck CJ
- Subjects
- Angiography, Child, Child, Preschool, Embolization, Therapeutic, Female, Humans, Injury Severity Score, Laparotomy, Male, Prospective Studies, Tomography, X-Ray Computed, Trauma Centers, Abdominal Injuries diagnostic imaging, Abdominal Injuries surgery, Wounds, Nonpenetrating diagnostic imaging, Wounds, Nonpenetrating surgery
- Abstract
Background: Pediatric intra-abdominal injuries (IAI) from blunt abdominal trauma (BAT) rarely require emergent intervention. For those children undergoing procedural intervention, our aim was to understand the timing and indications for operation and angiographic embolization., Methods: We prospectively enrolled children younger than 16 years after BAT at 14 Level I Pediatric Trauma Centers over a 1-year period. Patients with IAI who received an intervention (IAI-I) were compared with those who did not receive an intervention using descriptive statistics and univariate analysis; p less than 0.05 was considered significant., Results: Two hundred sixty-one (11.9%) of 2,188 patients had IAI. Forty-five (17.2%) IAI patients received an acute procedural intervention (38 operations, seven angiographic embolization). The mean age for patients requiring intervention was 7.1 ± 4.1 years and not different from the population. Most patients (88.9%) with IAI-I were normotensive. IAI-I patients were significantly more likely to have a mechanism of motor vehicle collision (66.7% vs. 38.9%), more likely to present as a Level I activation (44.4% vs. 26.9%), more likely to have a Glascow Coma Scale less than 14 (31.1% vs. 15.5%), and more likely to have an abnormal abdominal physical examination (93.3% vs. 65.7%) than patients that did not require acute intervention. All patients underwent computed tomography scan before intervention. Operations consisted of laparotomy (n = 21), laparoscopy converted to open (n = 11), and laparoscopy alone (n = 6). The most common surgical indications were hollow viscus injury (HVI) (11 small bowel, 10 colon, 6 small bowel/colon, 2 duodenum). All interventions for solid organ injury, including seven angioembolic procedures, occurred within 8 hours of arrival; many had hypotension and received a transfusion. Procedural interventions were more common for HVI than for solid organ injury (59.2% vs. 7.6%). Postoperative mortality from IAI was 2.6%., Conclusion: Acute procedural interventions for children with IAI from BAT are rare, predominantly for HVI, are performed early in the hospital course and have excellent clinical outcomes., Level of Evidence: Prognostic/epidemiologic study, level III; therapeutic study, level IV.
- Published
- 2017
- Full Text
- View/download PDF
32. Primary laparoscopic gastrojejunostomy tubes as a feeding modality in the pediatric population.
- Author
-
Onwubiko C, Weil BR, Bairdain S, Hall AM, Perkins JM, Thangarajah H, McSweeney ME, and Smithers CJ
- Subjects
- Child, Preschool, Female, Fundoplication adverse effects, Gastric Bypass, Humans, Infant, Intestinal Perforation etiology, Laparoscopy adverse effects, Male, Retrospective Studies, Enteral Nutrition adverse effects, Gastroesophageal Reflux surgery, Intubation, Gastrointestinal adverse effects
- Abstract
Purpose: Outcomes associated with primary laparoscopic gastrojejunal (GJ) tube placement in the pediatric population were evaluated., Methods: A single-institution, retrospective review examined patients undergoing laparoscopic GJ tube placement between June 2011 and December 2014. Outcomes included gastric feeding tolerance, subsequent fundoplication, complications, and mortality., Results: Ninety laparoscopic GJ tubes were placed. Median follow-up was 342days (interquartile range [IQR]=141-561days). Median patient age was 5months (IQR=3-11months) and weight was 5.2kg (IQR=4-8.4kg). The most common indications for placement were gastroesophageal reflux (n=85, 94.4%) and/or aspiration (n=40, 44.4%). Most common comorbidities included cardiac (n=34, 37.8%) and respiratory (n=29, 32.2%) diseases. The complication rate was 17.8%, including one case of intestinal perforation. Thirty-four (37.7%) patients transitioned to gastric feeding within 1year; time to conversion was 156days (IQR=117-210days); of those, 18.9% patients transitioned to oral feedings. A fundoplication was later performed in 4 children for persistent reflux. Mortality was 23.3% with no procedural-related deaths., Conclusion: Primary laparoscopically placed GJ tubes are a reliable means of enteral access for pediatric patients with gastric feeding intolerance. Many of these children are successfully transitioned to gastric and/or oral feedings over time. Further studies are needed to characterize which patients are best served with a GJ tube versus alternatives such as fundoplication., Level of Evidence: III (treatment) TYPE OF STUDY: Retrospective., (Copyright © 2017 Elsevier Inc. All rights reserved.)
- Published
- 2017
- Full Text
- View/download PDF
33. Focused assessment with sonography for trauma in children after blunt abdominal trauma: A multi-institutional analysis.
- Author
-
Calder BW, Vogel AM, Zhang J, Mauldin PD, Huang EY, Savoie KB, Santore MT, Tsao K, Ostovar-Kermani TG, Falcone RA, Dassinger MS, Recicar J, Haynes JH, Blakely ML, Russell RT, Naik-Mathuria BJ, St Peter SD, Mooney DP, Onwubiko C, Upperman JS, Zagory JA, and Streck CJ
- Subjects
- Abdominal Injuries surgery, Adolescent, Child, Child, Preschool, False Negative Reactions, Female, Humans, Male, Prognosis, Prospective Studies, Retrospective Studies, Sensitivity and Specificity, Tomography, X-Ray Computed, Trauma Centers, Wounds, Nonpenetrating surgery, Abdominal Injuries diagnostic imaging, Emergency Medical Services, Ultrasonography, Wounds, Nonpenetrating diagnostic imaging
- Abstract
Introduction: The utility of focused assessment with sonography for trauma (FAST) in children is poorly defined with considerable practice variation. Our purpose was to investigate the role of FAST for intra-abdominal injury (IAI) and IAI requiring acute intervention (IAI-I) in children after blunt abdominal trauma (BAT)., Methods: We prospectively enrolled children younger than 16 years after BAT at 14 Level I pediatric trauma centers over a 1-year period. Patients who underwent FAST were compared with those that did not, using descriptive statistics and univariate analysis; p value less than 0.05 was considered significant. FAST test characteristics were performed using computed tomography (CT) and/or intraoperative findings as the gold standard., Results: Two thousand one hundred eighty-eight children (age, 7.8 ± 4.6 years) were included. Eight hundred twenty-nine (37.9%) received a FAST, 340 of whom underwent an abdominal CT. Ninety-seven (29%) of these 340 patients had an IAI and 27 (7.9%) received an acute intervention. CT scan utilization after FAST was 41% versus 46% among those who did not receive FAST. The frequency of FAST among centers ranged from 0.84% to 94.1%. There was low correlation between FAST and CT utilization (r = -0.050, p < 0.001). Centers that performed FAST at a higher frequency did not have improved accuracy. The test performance of FAST for IAI was sensitivity, 27.8%; specificity, 91.4%; positive predictive value, 56.2%; negative predictive value, 76.0%; and accuracy, 73.2%. There were 81 injuries among the 70 false-negative FAST. The test performance of FAST for IAI-I was sensitivity, 44.4%; specificity, 88.5%; positive predictive value, 25.0%; negative predictive value, 94.9%; and accuracy, 85.0%. Fifteen children with a negative FAST received acute interventions. Among the 27 patients with true positive FAST examinations, 12 received intervention. All had an abnormal abdominal physical examination. No patient underwent intervention before CT scan., Conclusion: As currently used, FAST has a low sensitivity for IAI, misses IAI-I and rarely impacts management in pediatric BAT., Level of Evidence: Prognostic and epidemiologic study, level II; diagnostic tests or criteria study, level II; therapeutic/care management study, level III.
- Published
- 2017
- Full Text
- View/download PDF
34. The lost art of the splenorrhaphy.
- Author
-
Arbuthnot M, Onwubiko C, and Mooney D
- Subjects
- Child, Databases, Factual, Female, Humans, Male, Wounds, Nonpenetrating surgery, Diagnostic Imaging, Disease Management, Emergencies, Spleen diagnostic imaging, Spleen injuries, Splenectomy, Wounds, Nonpenetrating diagnosis
- Abstract
Background: In the case of the hemodynamically unstable child, splenorrhaphy is preferred to splenectomy to avert postsplenectomy sepsis. However, successful splenorrhaphy requires familiarity with the procedure. We sought to determine how many splenectomies or splenorrhaphies for trauma the average pediatric surgeon can be expected to perform during their career., Methods: The Pediatric Health Information System (PHIS) Database was queried for patients ≤18years coded with an International Classification of Diseases 9th Edition diagnosis code of a splenic injury from 2004 to 2013. Age, gender, grade of splenic injury, and operations performed were extracted. Numbers of pediatric surgeons per hospital were obtained., Results: 9567 children were identified. 2.1% underwent a splenectomy and 0.8% underwent a splenorrhaphy. The average surgeon performed 0.6 (SD=0.6) splenectomies and 0.2 (SD=0.4) splenorrhaphies for trauma. If these rates remain constant over time, the average surgeon would perform 1.8 (SD =1.7) splenectomies and 0.6 (SD =1.1) splenorrhaphies for trauma over a 30-year surgical career., Conclusion: Nonoperative management is associated with a host of benefits, but has resulted in a decrease in the experience level of the pediatric surgeons expected to perform an emergency splenectomy or splenorrhaphy when the unusual occasion arises., (Copyright © 2016 Elsevier Inc. All rights reserved.)
- Published
- 2016
- Full Text
- View/download PDF
35. The value of official reinterpretation of trauma computed tomography scans from referring hospitals.
- Author
-
Onwubiko C and Mooney DP
- Subjects
- Adolescent, Child, Child, Preschool, Female, Humans, Infant, Infant, Newborn, Male, Observer Variation, Pelvic Bones diagnostic imaging, Referral and Consultation, Retrospective Studies, Trauma Centers, Young Adult, Abdominal Injuries diagnostic imaging, Clinical Decision-Making methods, Patient Transfer, Pelvic Bones injuries, Spinal Fractures diagnostic imaging, Tomography, X-Ray Computed, Wounds, Nonpenetrating diagnostic imaging
- Abstract
Introduction: Historically, computed tomography (CT) scans of injured children obtained at referring emergency departments were not reinterpreted by trauma center radiologists at our institution, creating a dilemma for trauma physicians: rescan, use the outside interpretation, or interpret scans themselves. In 2010, our radiologists began reinterpreting all referring hospital trauma CT scans; this study examines the effect of that change., Methods: Transferred patients who had undergone an abdomen/pelvis CT (CTAP) scan between December 2010 and December 2012 were identified in our trauma registry. Pediatric radiologist reinterpretations were compared to referring hospital radiologist reports., Results: We identified 168 patients transferred to our institution with a CTAP. Seventy patients were excluded owing to lack of: complete study, referring hospital interpretation, or reinterpretation. Of the remaining 98 cases, 12 new injuries were identified: 3 splenic and 3 liver injuries, 1 adrenal hematoma, 2 pelvic fractures, 1 spinal fracture, 1 duodenal hematoma and 1 jejunal perforation. Three patients had solid organ injuries upgraded (grade II to III liver laceration; 2 renal lacerations with active extravasation initially missed), and 4 patients downgraded to no injury., Conclusion: Reinterpretation of referring hospital CT scans by pediatric radiologists is beneficial to appropriate management of pediatric trauma patients with concern for blunt abdominal trauma., (Copyright © 2016 Elsevier Inc. All rights reserved.)
- Published
- 2016
- Full Text
- View/download PDF
36. Laparoscopic Gastrojejunostomy Tube Placement in Infants with Congenital Cardiac Disease.
- Author
-
Onwubiko C, Bairdain S, Murphy AJ, McSweeney ME, Perkins J, Rathod RH, Baird C, and Smithers CJ
- Subjects
- Female, Humans, Infant, Male, Operative Time, Postoperative Complications, Treatment Outcome, Enteral Nutrition methods, Gastric Bypass methods, Heart Defects, Congenital therapy, Laparoscopy methods
- Abstract
Introduction: Gastrojejunostomy (GJ) tubes are an option for durable enteral access for critically ill infants with congenital cardiac disease who struggle with obtaining adequate nutrition., Materials and Methods: Infants weighing less than 10 kg with cardiac disease who received placement of a laparoscopic GJ tube from November 2011 to January 2015 were reviewed. The operative technique used an umbilical port for the camera and a single stab incision for the gastric access site. After insufflation to 5-8 mm Hg, the stomach was suspended to the abdominal wall, after which a dilator was maneuvered into a postpyloric position using laparoscopic visualization and fluoroscopy, and a glidewire was passed into the duodenum. The GJ tube was then fluoroscopically threaded over the glidewire; final position was confirmed by contrast injection., Results: There were 32 laparoscopic GJ tube placement operations performed; 7 (21.9%) of these tubes were standard single-unit GJ tubes, and 25 (78.1%) were low-profile gastrostomy tubes modified with a nasojejunal feeding tube threaded through the feeding port. Median patient age was 3.5 months (range, 0.75-11 months), with a median weight of 4.2 kg (range, 2.4-7.4 kg). Congenital defects were varied, including hypoplastic left heart syndrome and pulmonary vein stenosis. Median operative time was 62 minutes for isolated GJ placement (range, 35-114 minutes). There were three postoperative complications, resulting in a 30-day complication rate of 9.4%. Thirty-day mortality was 9.4% with no mortality related to the operation., Conclusions: Laparoscopic GJ tube placement may be performed safely in infants with cardiac disease and allows these patients to receive adequate nutrition despite intolerance of gastric feeding.
- Published
- 2015
- Full Text
- View/download PDF
37. Development of a Streptococcus pneumoniae keratitis model in mice.
- Author
-
Moore QC 3rd, McCormick CC, Norcross EW, Onwubiko C, Sanders ME, Fratkin J, McDaniel LS, O'Callaghan RJ, and Marquart ME
- Subjects
- Animals, Cornea microbiology, Cornea pathology, Corneal Edema etiology, Corneal Edema pathology, Eye Infections, Bacterial complications, Eye Infections, Bacterial pathology, Host-Pathogen Interactions, Humans, Keratitis pathology, Mice, Mice, Inbred Strains, Neutrophils pathology, Pneumococcal Infections complications, Pneumococcal Infections pathology, Disease Models, Animal, Eye Infections, Bacterial microbiology, Keratitis etiology, Pneumococcal Infections microbiology, Streptococcus pneumoniae isolation & purification
- Abstract
Background: Streptococcus pneumoniae is a common cause of bacterial keratitis, and models to examine the ocular pathogenesis of this bacterium would aid in efforts to treat pneumococcal keratitis. The aim of this study was to establish a murine model of pneumococcal keratitis., Methods: The corneas of A/J, BALB/c or C57BL/6 mice were scratched and topically infected with a clinical strain of S. pneumoniae. Slitlamp examination (SLE), enumeration of bacteria in the corneas and histology were performed., Results: Bacteria were recovered from the eyes of A/J mice on postinfection (PI) days 1 [1.96 +/- 0.61 log(10) colony-forming units (CFU)] and 3 (1.41 +/- 0.71 log(10) CFU). SLE scores were significantly higher in the infected A/J mice as compared to the BALB/c or C57BL/6 mice on PI day 3 (p < 0.0001) and steadily increased over time, reaching a maximal value of 3.00 +/- 0.35 on PI day 10. Histopathology revealed stromal edema and the influx of polymorphonuclear leukocytes on PI days 7 and 10, and corneal disruption on PI day 7., Conclusions: S. pneumoniae keratitis was established in A/J mice, but not BALB/c or C57BL/6 mice.
- Published
- 2009
- Full Text
- View/download PDF
38. A comparison of pneumolysin activity and concentration in vitro and in vivo in a rabbit endophthalmitis model.
- Author
-
Sanders ME, Norcross EW, Moore QC, Onwubiko C, King LB, Fratkin J, and Marquart ME
- Abstract
The purpose of this study was to determine whether the in vitro activity and concentration of Streptococcus pneumoniae pneumolysin correlated to the pathogenesis of S. pneumoniae endophthalmitis. Five S. pneumoniae clinical endophthalmitis strains were grown in media to similar optical densities (OD), and extracellular milieu was tested for pneumolysin activity by hemolysis of rabbit red blood cells. Pneumolysin concentration was determined using a sandwich ELISA. Rabbit vitreous was injected with 10(2) colony-forming units (CFU) of 1 of 2 different strains with low hemolytic activity (n = 10 and 12 for strains 4 and 5, respectively) or 1 of 3 different strains with high hemolytic activity (n = 12 per strain). Pathogenesis of endophthalmitis infection was graded by slit lamp examination (SLE) at 24 hours post-infection. Bacteria were recovered from infected vitreous and quantitated. The SLE scores of eyes infected with strains having high hemolytic activity were significantly higher than the scores of those infected with strains having low hemolytic activity (P < 0.05). Pneumolysin concentration in vitro, however, did not correlate with hemolysis or severity of endophthalmitis. Bacterial concentrations from the vitreous infected with 4 of the strains were not significantly different (P > 0.05). These data suggest that pneumolysin hemolytic activity in vitro directly correlates to the pathogenesis of S. pneumoniae endophthalmitis. The protein concentration of pneumolysin, however, is not a reliable indicator of pneumolysin activity.
- Published
- 2008
- Full Text
- View/download PDF
39. Cross-sectional study of nasopharyngeal carriage of Streptococcus pneumoniae in human immunodeficiency virus-infected adults in the conjugate vaccine era.
- Author
-
Onwubiko C, Swiatlo E, and McDaniel LS
- Subjects
- Adult, Aged, Anti-Bacterial Agents pharmacology, Bacterial Typing Techniques, CD4 Lymphocyte Count, Cross-Sectional Studies, DNA Fingerprinting, Female, Genotype, Humans, Male, Microbial Sensitivity Tests, Middle Aged, Pneumococcal Infections microbiology, Sequence Analysis, DNA, Serotyping, Streptococcus pneumoniae immunology, Streptococcus pneumoniae physiology, Vaccines, Conjugate immunology, Carrier State epidemiology, Carrier State microbiology, HIV Infections complications, Nasopharynx microbiology, Pneumococcal Infections epidemiology, Pneumococcal Vaccines immunology, Streptococcus pneumoniae classification, Streptococcus pneumoniae isolation & purification
- Abstract
Human immunodeficiency virus (HIV)-infected patients have an increased rate of pneumococcal infections. Within the HIV-infected population, patients with low CD4(+) cell counts have a higher rate of pneumococcal infection. The purpose of our study was to determine pneumococcal carriage and to examine the serotypes carried by HIV-infected patients after the introduction of the conjugate vaccine. Nasopharyngeal swabs were obtained from patients during routine clinic visits. Samples were cultured on blood agar plates with gentamicin and screened for alpha-hemolysis, optochin sensitivity, and bile solubility. Capsular serotypes were determined by multiplex PCR, multibead assay, or latex agglutination. Antibiotic susceptibility was determined by the Etest method. Multilocus sequence typing was also performed. Of the 175 patients enrolled, 120 patients had absolute CD4(+) cell counts above 200/mm(3) and 55 had counts below 200/mm(3). A total of six (3.4%) patients carried pneumococci. All but one of these patients had received the 23-valent pneumococcal vaccine within the previous 5 years. Five of the isolates were serotypes that are not included in the 7-valent conjugate vaccine. Immunization with the pneumococcal polysaccharide vaccine does not prevent colonization in HIV-infected patients; however, the observation of carriage of serotypes not included in the conjugate vaccine may be due to herd immunity and serotype replacement effects in the general population.
- Published
- 2008
- Full Text
- View/download PDF
40. Protection from Streptococcus pneumoniae keratitis by passive immunization with pneumolysin antiserum.
- Author
-
Green SN, Sanders M, Moore QC 3rd, Norcross EW, Monds KS, Caballero AR, McDaniel LS, Robinson SA, Onwubiko C, O'Callaghan RJ, and Marquart ME
- Subjects
- Animals, Bacterial Proteins immunology, Colony Count, Microbial, Cornea microbiology, Corneal Ulcer microbiology, Disease Models, Animal, Enzyme-Linked Immunosorbent Assay, Eye Infections, Bacterial microbiology, Pneumococcal Infections microbiology, Rabbits, Streptococcus pneumoniae immunology, Vaccination, Antibodies, Bacterial administration & dosage, Corneal Ulcer prevention & control, Eye Infections, Bacterial prevention & control, Immunization, Passive, Pneumococcal Infections prevention & control, Pneumococcal Vaccines administration & dosage, Streptolysins immunology
- Abstract
Purpose: To determine whether passive immunization with pneumolysin antiserum can reduce corneal damage associated with pneumococcal keratitis., Methods: New Zealand White rabbits were intrastromally injected with Streptococcus pneumoniae and then passively immunized with control serum, antiserum against heat-inactivated pneumolysin (HI-PLY), or antiserum against cytotoxin-negative pneumolysin (psiPLY). Slit lamp examinations (SLEs) were performed at 24, 36, and 48 hours after infection. An additional four corneas from rabbits passively immunized with antiserum against psiPLY were examined up to 14 days after infection. Colony forming units (CFUs) were quantitated from corneas extracted at 20 and 48 hours after infection. Histopathology of rabbit eyes was performed at 48 hours after infection., Results: SLE scores at 36 and 48 hours after infection were significantly lower in rabbits passively immunized with HI-PLY antiserum than in control rabbits (P < or = 0.043). SLE scores at 24, 36, and 48 hours after infection were significantly lower in rabbits passively immunized with psiPLY antiserum than in control rabbits (P < or = 0.010). The corneas of passively immunized rabbits that were examined up to 14 days after infection exhibited a sequential decrease in keratitis, with an SLE score average of 2.000 +/- 1.586 at 14 days. CFUs recovered from infected corneas were not significantly different between each experimental group and the respective control group at 20 or 48 hours after infection (P > or = 0.335). Histologic sections showed more corneal edema and polymorphonuclear leukocyte (PMN) infiltration in control rabbits compared with passively immunized rabbits., Conclusions: HI-PLY and psiPLY both elicit antibodies that provide passive protection against S. pneumoniae keratitis.
- Published
- 2008
- Full Text
- View/download PDF
41. Factor H binding to PspC of Streptococcus pneumoniae increases adherence to human cell lines in vitro and enhances invasion of mouse lungs in vivo.
- Author
-
Quin LR, Onwubiko C, Moore QC, Mills MF, McDaniel LS, and Carmicle S
- Subjects
- Animals, Bacteremia, Cell Line, Colony Count, Microbial, Disease Models, Animal, Endothelial Cells microbiology, Epithelial Cells microbiology, Humans, Immunoglobulin A, Secretory metabolism, Mice, Mice, Inbred CBA, Streptococcus pneumoniae growth & development, Bacterial Adhesion, Bacterial Proteins metabolism, Complement Factor H metabolism, Lung microbiology, Pneumonia, Pneumococcal microbiology, Streptococcus pneumoniae pathogenicity
- Abstract
Pneumococcal surface protein C (PspC) binds to both human secretory immunoglobulin A (sIgA) and complement factor H (FH). FH, a regulator of the alternative pathway of complement, can also mediate adherence of different host cells. Since PspC contributes to adherence and invasion of host cells, we hypothesized that the interaction of PspC with FH may also mediate adherence of pneumococci to human cells. In this study, we investigated FH- and sIgA-mediated pneumococcal adherence to human cell lines in vitro. Adherence assays demonstrated that preincubation of Streptococcus pneumoniae D39 with FH increased adherence to human umbilical vein endothelial cells (HUVEC) 5-fold and to lung epithelial cells (SK-MES-1) 18-fold, relative to that of D39 without FH on the surface. The presence of sIgA enhanced adherence to SK-MES-1 6-fold and to pharyngeal epithelial cells (Detroit 562) 14-fold. Furthermore, sIgA had an additive effect on adherence to HUVEC; specifically, preincubation of D39 with both FH and sIgA led to a 21-fold increase in adherence. Finally, using a mouse model, we examined the significance of the FH-PspC interaction in pneumococcal nasal colonization and lung invasion. Mice intranasally infected with D39 preincubated with FH had increased bacteremia and lung invasion, but they had similar levels of nasopharyngeal colonization compared to that of mice challenged with D39 without FH.
- Published
- 2007
- Full Text
- View/download PDF
42. Characterization of Streptococcus pneumoniae isolated from children with otitis media.
- Author
-
Onwubiko C, Shires C, Quin LR, Swiatlo E, and McDaniel LS
- Subjects
- Bacterial Capsules analysis, Bacterial Proteins analysis, Child, Preschool, Drug Resistance, Bacterial, Humans, Microbial Sensitivity Tests, Polymerase Chain Reaction methods, Streptococcus pneumoniae drug effects, Streptococcus pneumoniae isolation & purification, Otitis Media microbiology, Streptococcus pneumoniae classification
- Abstract
Streptococcus pneumoniae is the main causative agent of acute otitis media in children. Serotype-based vaccines have provided some protection against otitis media, but not as much as anticipated, demonstrating the need for alternative vaccine options. Pneumococcal otitis media isolates were obtained from children 5 years old or younger from hospitals around Mississippi in the prevaccine era (1999-2000). These isolates were compared by capsular typing, pneumococcal surface protein A (PspA) family typing, antibiotic susceptibility, and DNA fingerprinting. Our study shows that there is great genetic variability among pneumococcal clinical isolates of otitis media, except with regard to PspA. Therefore, efforts focused on the development of a PspA-based pneumococcal vaccine would be well placed.
- Published
- 2007
- Full Text
- View/download PDF
43. Interaction of clinical isolates of Streptococcus pneumoniae with human complement factor H.
- Author
-
Quin LR, Onwubiko C, Carmicle S, and McDaniel LS
- Subjects
- Bacterial Proteins analysis, Complement Factor H analysis, Complement Factor H metabolism, Flow Cytometry, Humans, Membrane Proteins analysis, Pneumococcal Infections microbiology, Serotyping, Streptococcus pneumoniae classification, Streptococcus pneumoniae isolation & purification, Bacterial Proteins metabolism, Membrane Proteins metabolism, Streptococcus pneumoniae pathogenicity
- Abstract
PspC recruits complement factor H (FH) to the pneumococcal surface. While there is differential expression of pspC during infection, detection of PspC on the surface of viable pneumococci is difficult due to variability among PspCs. We analyzed FH binding to detect PspC expression on the surface of pneumococcal isolates from different pathological sources. Using flow cytometry, we investigated FH-binding to 89 low-passage clinical isolates classified by disease manifestation (systemic, mucosal, or carriage). Carriage isolates recruited significantly more FH to their surfaces than either systemic or mucosal isolates, and this binding was independent of capsular serotype.
- Published
- 2006
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.