bluuebunny/crossref_metadata_2025_split huggingface dataset:
Magnification and accommodation with phakic intraocular lenses
Authors: Langenbucher Achim , Szentmáry Nóra , Seitz Berthold 
Published: May 2007

AbstractBackground and Purpose:  The calculation of phakic lenses (PL) was described by van der Heijde et al. [Klin. Monatsbl. Augenheilkd (1988) Vol. 193, pp. 99–102], but a formalism for estimating relative magnification compared with spectacle correction and accommodation effects are not yet published. The purpose of this study was to describe a mathematical strategy for calculating PL and relative magnification as a function of object vergence (phakic accommodation).Methods:  Parameters used for the calculations are the spectacle refraction before and after (target refraction) surgery, the vertex distance, corneal refraction, and the predicted position of the phakic intraocular lens. The lens power is determined as the difference in vergences between the spectacle‐corrected eye and the uncorrected eye at the reference plane of the predicted lens position. If we simplify the crystalline lens to a single refracting surface located at the principal plane of the crystalline lens, the vergence of the eye with spectacle correction and with PL is determined as a function of object distance [object vergence 0 D (infinity) to 10 D (object at a distance of 10 cm)] to evaluate accommodation effects of the crystalline lens.Results:  The method was applied to two clinical examples. In example 1 we calculated the power of a PL for correction of a 10‐D myopia and determined the relative magnification and the vergence at the principal plane of the crystalline lens as a function of object vergence. Magnification gain increases with objects at near from 17% to 26%, whereas the vergence at the principal plane of the crystalline lens changes by 3.04 D less than in the spectacle‐corrected eye. In example 2, a 20‐D myopia was corrected with a PL. The gain in magnification changed from 33% to 58% with nearer objects. The change in vergence at the principal plane of the crystalline lens with objects at near was much higher with the PL compared with the spectacle correction, which implies that the refractive change necessary for focusing objects at near distance is much higher in the PL correction.Conclusions:  Even if the predictability of postoperative refraction with PL is comparable or better than in other methods of correcting high or excessive ametropia, the effects of lateral magnification change and accommodation have to be considered to avoid image‐size disparities (aniseikonia) and to maintain binocular vision, especially with monocular PL implantation and anisometropia.
Circular polarization biomicroscopy: a method for determining human corneal stromal lamellar organization in vivo
Authors: Misson Gary P. 
Published: May 2007

AbstractThe theory of polarization biomicroscopy is explored using Stokes vectors and Mueller matrices. It is established that circular polarization can be used to simultaneously detect birefringent elements at any orientation unlike orientation‐sensitive techniques using linear polarized light alone. A method of biomicroscopy using circular polarized light is described and tested in a physical model. The method is then used to investigate the lamellar structure of human corneas in vivo in pairs of eyes of 38 subjects. An approximate confocal elliptic/hyperbolic distribution of stromal fibrils, presumed to be collagen, is clearly identified within central and intermediate areas of the cornea. All subjects tested demonstrate approximate mirror symmetry between pairs of eyes typically with a preferred orientation of central fibrils at approximately 15° to the horizontal in a superotemporal–inferonasal direction.
Pediatric Patient Safety Events during Hospitalization: Approaches to Accounting for Institution‐Level Effects
Authors: Slonim Anthony D. , Marcin James P. , Turenne Wendy , Hall Matt , Joseph Jill G. 
Published: May 2007

Objective. To determine the rates, patient, and institutional characteristics associated with the occurrence of patient safety indicators (PSIs) in hospitalized children and the degree of statistical difference derived from using three approaches of controlling for institution level effects.Data Source. Pediatric Health Information System Dataset consisting of all pediatric discharges (<21 years of age) from 34 academic, freestanding children's hospitals for calendar year 2003.Methods. The rates of PSIs were computed for all discharges. The patient and institutional characteristics associated with these PSIs were calculated. The analyses sequentially applied three increasingly conservative methods to control for the institution‐level effects robust standard error estimation, a fixed effects model, and a random effects model. The degree of difference from a “base state,” which excluded institution‐level variables, and between the models was calculated. The effects of these analyses on the interpretation of the PSIs are presented.Principal Findings. PSIs are relatively infrequent events in hospitalized children ranging from 0 per 10,000 (postoperative hip fracture) to 87 per 10,000 (postoperative respiratory failure). Significant variables associated PSIs included age (neonates), race (Caucasians), payor status (public insurance), severity of illness (extreme), and hospital size (>300 beds), which all had higher rates of PSIs than their reference groups in the bivariable logistic regression results. The three different approaches of adjusting for institution‐level effects demonstrated that there were similarities in both the clinical and statistical significance across each of the models.Conclusions. Institution‐level effects can be appropriately controlled for by using a variety of methods in the analyses of administrative data. Whenever possible, resource‐conservative methods should be used in the analyses especially if clinical implications are minimal.
Quality by Any Other Name?: A Comparison of Three Profiling Systems for Assessing Health Care Quality
Authors: Kerr Eve A. , Hofer Timothy P. , Hayward Rodney A. , Adams John L. , Hogan Mary M. , McGlynn Elizabeth A. , Asch Steven M. 
Published: May 2007

Objective. Many performance measurement systems are designed to identify differences in the quality provided by health plans or facilities. However, we know little about whether different methods of performance measurement provide similar answers about the quality of care of health care organizations. To examine this question, we used three different measurement approaches to assess quality of care delivered in veteran affairs (VA) facilities.Data Sources/Study Setting. Medical records for 621 patients at 26 facilities in two VA regions.Study Design. We examined agreements in quality conclusions using: focused explicit (38 measures for six conditions/prevention), global explicit (372 measures for 26 conditions/prevention), and structured implicit review physician‐rated care (a single global rating of care for three chronic conditions and overall acute, chronic and preventive care). Trained nurse abstractors and physicians reviewed all medical records. Correlations between scores from the three systems were adjusted for measurement error in each using multilevel regression models.Results. Intercorrelations of scores were generally moderate to high across all three systems, and rose with adjustment for measurement error. Site‐level correlations for prevention and diabetes care were particularly high. For example, adjusted for measurement error at the site level, prevention quality was correlated at 0.89 between the implicit and global systems, 0.67 between implicit and focused, and 0.73 between global and focused systems.Conclusions. We found moderate to high agreement in quality scores across the three profiling systems for most clinical areas, indicating that all three were measuring a similar construct called “quality.” Adjusting for measurement error substantially enhanced our ability to identify this underlying construct.
Mild donor liver steatosis has no impact on hepatitis C virus fibrosis progression following liver transplantation
Authors: Botha Jean F. , Thompson Eric , Gilroy Richard , Grant Wendy J. , Mukherjee Sandeep , Lyden Elizabeth R. , Fox Ira J , Sudan Debra L. , Shaw Byers W. , Langnas Alan N. 
Published: May 2007

AbstractBackground: This study examines the impact of donor liver macrovesicular steatosis on recurrence of hepatitis C virus (HCV) disease after liver transplantation.Methods: Between 1998 and 2004, 113 patients underwent liver transplantation for HCV‐related cirrhosis. Time to histologic recurrence (fibrosis score ≥2) was the primary endpoint of the study. Recurrence was graded according to the system of Ludwig and Batts. A Cox's proportional hazard regression model was used to analyse the association between donor liver steatosis and HCV recurrence.Results: Recurrence‐free survival for patients who received steatotic grafts was 82% and 47% at 1 and 4 years, respectively, and 81% and 52% for patients who received a non‐steatotic liver. Donor macrovesicular steatosis (5–45%) was found to have no impact on HCV recurrence (P=0.47). Donor age (P=0.02) and cold ischaemia time (P=0.01) were found to increase the relative risk of HCV recurrence. The estimated risk of HCV recurrence increased by 23% for every 10‐year increase in donor age. Similarly the risk of recurrence increased by 13% for every 1‐h increase in cold ischaemia time.Conclusion: Mild‐moderate donor liver macrovesicular steatosis has no impact on HCV recurrence after liver transplantation for HCV‐related cirrhosis. Cold ischaemia time and donor age increased the likelihood of HCV recurrence.
Documenting a transfusion: how well is it done?
Authors: Rock Gail , Berger Ray , Filion Diane , Touche Donna , Neurath Doris , Wells George , ElSaadany Susie , Afzal Mohammed 
Published: May 2007

BACKGROUND: Current practice in transfusion medicine promotes clear documentation of transfusion‐related events including the fact that the patient has been informed of the related risks and benefits.STUDY DESIGN AND METHODS: A retrospective review of 1005 patient charts was carried out to determine documentation.RESULTS: Most patients were from general surgery (10.8%) and cardiac surgery (14.1%). In 75 percent of cases the physician had not documented that any discussion had occurred regarding the risks and/or benefits or alternatives. Only 12 percent of charts included information that the patient was subsequently told what blood components were given to them. The discharge summary recorded transfusion information in 32.1 percent of cases whereas the consult note had this information in 26.3 percent. Chart records matched the transfusion medicine records in 60.6 percent of cases. The most common error was in the blood unit identification number.CONCLUSIONS: While accepted in theory, the practice of documenting patient information on transfusion is not well done.
Proactive administration of platelets and plasma for patients with a ruptured abdominal aortic aneurysm: evaluating a change in transfusion practice
Authors: Johansson Pär I. , Stensballe Jakob , Rosenberg Iben , Hilsløv Tanja L. , Jørgensen Lisbeth , Secher Niels H. 
Published: May 2007

BACKGROUND:Continued hemorrhage remains a major contributor of mortality in massively transfused patients and those who survive have a higher platelet (PLT) count and a shorter prothrombin time and activated partial thromboplastin time (APTT) than nonsurvivors. It was considered that early substitution with PLTs and fresh‐frozen plasma (FFP) would prevent development of coagulopathy and thus improve survival.STUDY DESIGN AND METHODS:Survival of patients undergoing surgery for a ruptured abdominal aortic aneurysm (rAAA) was compared after implementing a proactive transfusion therapy encompassing two pooled buffy‐coat PLT concentrates (PBPCs) immediately when a rupture of the aorta was suspected and again 30 minutes before aortic unclamping together with FFP administered in a 1:1 ratio to the amount of red blood cells (RBCs) with that of a control group receiving transfusion therapy according to existing recommendations.RESULTS:The intervention group (n = 50) had a higher PLT count at arrival at the intensive care unit compared to the control group (n = 82; 155 × 109/L vs. 69 × 109/L; p < 0.0001), shorter APTT (39 sec vs. 44 sec; p < 0.001), fewer postoperative transfusions (RBCs, 2 vs. 6; FFP, 2 vs. 4; and PBPCs, 0 vs. 1; p < 0.01), and a higher 30‐day survival rate (66% vs. 44%; p = 0.02).CONCLUSION:This study suggests that proactive administration of PLTs and FFP improves coagulation competence, reduces postoperative hemorrhage, and increases survival in massively bleeding rAAA patients.
The epidemiology of transfusion‐associated hepatitis C in a children's hospital
Authors: Luban Naomi L.C. , Colvin Camilla A. , Mohan Parvathi , Alter Harvey J. 
Published: May 2007

BACKGROUND:Children transfused with blood and blood products before 1992 are at risk for chronic hepatitis C virus (HCV) infection. To determine the prevalence of HCV infection and risks associated with acquisition of HCV, a single‐institution lookback study was performed.STUDY DESIGN AND METHODS:A total of 5473 infants and children who received transfusions between 1982 and 1992 were identified. A control population of 600 age‐, sex‐, race‐ and zip code–matched children who did not receive transfusions with the same exclusions provided background seroprevalence data. Patients were tested for antibodies to HCV, confirmed with second generation recombinant immunoblot assay (RIBA) and when appropriate quantitative and qualitative HCV RNA by reverse transcription polymerase chain reaction (PCR). Viral persistence was assessed by serial PCR determinations for HCV RNA.RESULTS:Of the 5473 eligible patients, 4726 were locatable and 2758 were tested. Forty‐three children (1.6%) were persistently anti‐HCV enzyme immunoassay (EIA)–positive, confirmed by RIBA; 39 were positive for the presence of HCV RNA. Four cleared their virus as assessed by two negative HCV PCRs 6 months apart. There was a borderline higher number of children with HCV who received fresh whole blood than those who tested HCV‐negative.CONCLUSION:Because HCV infection is generally asymptomatic, children are not identified unless they are specifically tested. We identified, enrolled, tested, and confirmed a new diagnosis of HCV infection in 43 patients. As HCV treatments become increasingly effective, it is important to identify silently infected individuals, particularly when the infection was iatrogenically induced.
Successful in vivo recovery and extended storage of additive solution (AS)‐5 red blood cells after deglycerolization and resuspension in AS‐3 for 15 days with an automated closed system
Authors: Bandarenko Nicholas , Cancelas Jose , Snyder Edward L. , Hay Shauna N. , Rugg Neeta , Corda Tammy , Joines Amy D. , Gormas Jennifer F. , Pratt Gayle P. , Kowalsky Richard , Rose Michael , Rose Leslie , Foley Jim , Popovsky Mark A. 
Published: May 2007

BACKGROUND: Previously, cryopreserved red blood cell (RBC) units derived from CPD/AS‐5 whole‐blood (WB) collections have been limited to 24 hours postthaw storage (1‐6°C).STUDY DESIGN AND METHODS: Sixty‐four leukoreduced (LR) and 54 nonleukoreduced (NLR) AS‐5 (n = 118) RBC units from 500‐mL WB collections were stored for 6 days, glycerolized, frozen (−70 ± 5°C) for at least 14 days, thawed, deglycerolized, and stored (1‐6°C) for 15 days resuspended in AS‐3, using an automated closed‐system cell processor (ACP 215, Haemonetics). Frozen units were stored in either ethylene vinyl acetate (EVA) or polyvinylchloride (PVC) bags. In vitro parameters were tested in all units 15 days after deglycerolization. In vivo 24‐hour recovery was measured in 77 of 118 donors.RESULTS: Postdeglycerolization in vitro RBC mass recoveries (mean ± SD) were 96.8 ± 5.7 and 94.7 ± 5.6% for EVA LR and NLR units, respectively, and 97.3 ± 6.2 and 94.7 ± 6.2% for PVC LR and NLR units, based on unit weight and hematocrit after sampling for in vitro testing, immediately before glycerolization. Hemoglobin content (g/unit, mean ± SD) after deglycerolization was 40.4 ± 5.6 and 42.6 ± 6.0 for EVA LR and NLR units, respectively, and 40.7 ± 4.8 and 43.0 ± 7.7 for PVC LR and NLR units. Hemolysis was 0.61 ± 0.23 and 0.54 ± 0.16% for EVA LR and NLR units, and 0.47 ± 0.14 and 0.43 ± 0.12% for PVC LR and NLR units. In vivo 24‐hour recoveries on Day 15 were 83.0 ± 6.7% (PVC NLR) up to 86.2 ± 5.7% (EVA NLR).CONCLUSION: With processing on the ACP 215 system, CPD/AS‐5 LR and NLR thawed RBC units can be stored for up to 14 days after frozen storage at −65°C or colder in EVA or PVC bags with acceptable in vivo and in vitro RBC quality.
In vitro differentiation of epithelial cells cultured from human periodontal ligament
Authors: Shimonishi M. , Hatakeyama J. , Sasano Y. , Takahashi N. , Uchida T. , Kikuchi M. , Komatsu M. 
Published: May 2007

Background and Objective:  Alkaline phosphatase and noncollagenous bone proteins are produced prior to cementum formation. While it has been suggested that epithelial rests of Malassez are involved in cementum formation, little is known about the relationship between epithelial rests of Malassez and cementum formation. The purpose of the present study was to determine whether the epithelial rests of Malassez cells cultured from human periodontal ligament can produce alkaline phosphatase and noncollagenous bone proteins, such as osteopontin, osteocalcin and bone sialoprotein.Material and Methods:  An outgrowth of putative epithelial rests of Malassez cells was produced from periodontal ligament explant, and second passage cultures were used in the experiments. Human gingival epithelial cells and periodontal ligament fibroblasts were used as controls. The expression levels of amelogenin were analyzed by immunostaining and in situ hybridization. Furthermore, the expression levels of alkaline phosphatase and noncollagenous bone proteins were assessed by immunostaining and reverse transcription–polymerase chain reaction.Results:  Amelogenin, alkaline phosphatase and osteopontin proteins and their corresponding mRNAs were detected at high levels in putative epithelial rests of Malassez cells. Osteocalcin and bone sialoprotein were not expressed in putative epithelial rests of Malassez cells. Alkaline phosphatase and noncollagenous bone proteins were seen in periodontal ligament fibroblasts, but not in gingival epithelial cells.Conclusion:  Our results suggest that putative epithelial rests of Malassez cells cultured alone do not transform into maturing cells to form the cementum, but may play a potential role in the mineralization process.
Leptin, IL‐10 and Inflammatory Markers (TNF‐α, IL‐6 and IL‐8) in Pre‐Eclamptic, Normotensive Pregnant and Healthy Non‐Pregnant Women
Authors: Sharma Alpana , Satyam Abhigyan , Sharma Jai Bhagwan 
Published: May 2007

ProblemDespite progress in immunobiology, pre‐eclampsia (PE) remains one of the most common reasons for women to die during pregnancy. The widespread pathophysiological mechanisms are endothelial dysfunction, oxidative stress and inflammation. The aim of this study was to assess the alteration in the levels of leptin, interleukin (IL)‐10 and inflammatory cytokines [tumour necrosis factor (TNF)‐α, IL‐6 & IL‐8] in pre‐eclamptic (severe and mild), healthy pregnant and non‐pregnant women and correlate these parameters with disease severity.Method of studyThe levels of leptin, IL‐10 and inflammatory cytokines were measured by high sensitivity enzyme‐linked immunoabsorbant assay. The study subjects were 54 pre‐eclamptic women (ten severe and 45 milder), compared by age matched 50 healthy pregnant and 27 non‐pregnant women. Kruskal–Wallis non‐parametric analyses of variance followed by Mann–Whitney U‐test were used for statistical analysis.ResultsThe levels of leptin, TNF‐α, IL‐6 & IL‐8 in pre‐eclamptic subjects were increased significantly when compared with the healthy control pregnant and non‐pregnant (P < 0.000). The concentration of IL‐10 has shown different pattern as its level decreased significantly (0.001) in pre‐eclamptic women (overall) in comparison with control subjects (pregnant & non‐pregnant). A combination of 80% or higher sensitivity and specificity was seen in the parameters analysed, except IL‐8 and IL‐10.ConclusionOur findings suggest a relationship among TNF‐α, IL‐6, IL‐8, IL‐10 and leptin and indicate that altered levels of above markers in PE might be used as markers of pro‐inflammation/anti‐inflammation and endothelial dysfunction in pre‐eclamptic pregnancies. These results also advocate the abnormal leptin and cytokine responses in mother, which might be involved in the pathogenesis of PE.
Redirection of Cytokine Production By Lymphocytes From Women with Pre‐Term Delivery By Dydrogesterone
Authors: Raghupathy Raj , Al Mutawa Esraa , Makhseed Ma'asoumah , Al‐Azemi Majedah , Azizieh Fawaz 
Published: May 2007

ProblemTo study the ability of dydrogesterone to modulate the production of pro‐inflammatory and anti‐inflammatory cytokines by lymphocytes from women undergoing pre‐term delivery (PTD).Method of studyPeripheral blood mononuclear cells (PBMC) from 18 subjects undergoing PTD were stimulated with the mitogen phytohemagglutinin in the presence and absence of progesterone and dydrogesterone. The levels of interferon (IFN)‐γ, tumor necrosis factor (TNF)‐α, interleukin (IL)‐4, and IL‐10 in culture supernatants were then estimated by enzyme‐linked immunoabsorbant assay. Cytokine production in the presence and absence of progesterone and dydrogesterone were compared.ResultsThe exposure of PBMC to dydrogesterone resulted in a significant inhibition in the production of the pro‐inflammatory cytokines IFN‐γ and TNF‐α and a significant increase in the levels of the anti‐inflammatory cytokine IL‐4, resulting in a substantial shift in the ratio of Th1/Th2 cytokines.ConclusionDydrogesterone induces a shift in cytokine bias, by inhibiting pro‐inflammatory cytokine production and increasing anti‐inflammatory cytokine production.
The Impact of Leukemia Inhibitory Factor in Uterine Flushing on the Reproductive Potential of Infertile Women – A Prospective Study
Authors: Mikolajczyk Mateusz , Wirstlein Przemyslaw , Skrzypczak Jana 
Published: May 2007

ProblemTo determine the value of leukemia inhibitory factor (LIF) assessment for predicting the reproductive outcome.Method of studyTwo phase study. Phase I: assessment of LIF in uterine flushing. Phase II: 1,5 years after examining the last patient, a questionnaire was sent to all participants of the phase I. Phase I: Uterine flushing and endometrial samples were collected during implantation window from infertile patients with stage I/II endometriosis (n = 14), patients with idiopathic infertility (n = 27), luteal phase deficiency (n = 13), and fertile control (n = 21). LIF was assessed in uterine flushings in all patients by ELISA. In endometrium, semiquantitative RT‐PCR was performed for LIF mRNA expression. Phase II: questionnaire has been sent to all infertile women taking part in the first phase of the experiment, regarding their reproductive outcome.Results65.4% patients who had returned the questionnaire did get pregnant. LIF concentration at a cut‐off point of 2.31 pg/ml had a 95.7% sensitivity and 81.8% specificity in predicting the reproductive outcome.ConclusionThis prospective study for the first time in literature indicates that the LIF assessment can be used as a predictor of reproductive success.