bluuebunny/crossref_metadata_2025_split huggingface dataset:
Positron emission tomography scanning in the setting of post‐transplant lymphoproliferative disorders
Authors: Blaes Anne H. , Cioc Adina M. , Froelich Jerry W. , Peterson Bruce A. , Dunitz Jordan M. 
Published: July 2009

Abstract:  Background:  Post‐transplant lymphoproliferative disorder (PTLD) is a serious complication of transplantation. We examined the role of positron emission tomography (PET) scanning in PTLD.Methods:  All patients treated for PTLD from 2001–2006 who also underwent PET scans were reviewed.Results:  Nineteen PTLD patients were included. Seventeen patients had PET scans for staging at diagnosis. Of these, two patients with primary central nervous system lymphoma and one patient with only bone marrow involvement after complete surgical resection of a bowel lesion had no abnormalities on CT or PET scan. The remaining patients had measurable, extracranial disease by CT scan and PET scan. The median maximum standard uptake value was 8.2 (range 3–30). Thirteen patients had a PET scan following treatment. Eleven of 13 patients had a complete response (CR). Two of 13 patients had persistent disease following therapy; in one of these patients, relapsed disease was documented by PET scan alone. Of the 11 patients with CR, three patients relapsed shortly thereafter. In each case, at the time of relapse, the PET scan confirmed recurrent disease regardless of histopathologic subtype.Conclusions:  PET scans may have a role in the staging and follow‐up of patients with PTLD. Additional prospective studies are warranted.
Post‐transplant erythrocytosis: a disappearing phenomenon?
Authors: Kiberd Bryce A. 
Published: July 2009

Abstract: Background: Erythrocytosis is relatively common post‐kidney transplantation and may have adverse consequences. This study examined whether the incidence of erythrocytosis has remained stable over time and explored the impact of this condition on patient outcomes.Methods: This was a retrospective single center review of an incidence cohort (transplanted between 1993 and 2005). Predictors of erythrocytosis and hemoglobin levels and subsequent patient and allograft survival were examined.Results: Erythrocytosis (hemoglobin >170 g/L for >1 month) was observed in 59 of 511 recipients. Erythrocytosis developed in only 8.1% of those transplanted from 1997 to 2005, compared with 18.7% in those transplanted from 1993 to 1996 (p = 0.0005). Independent predictive factors were use of angiotensin converting enzyme inhibitors/angiotensin receptor blockers (ACEi/ARBs) (HR 0.176, 95% CI 0.040–0.71, p = 0.016), male gender (HR 3.72, 95% CI 1.54–9.0, p = 0.003), and mycophenolic acid agents (HR 0.49, 95% CI 0.237–0.99, p = 0.049). Patients with erythrocytosis had superior overall survival (HR for death 0.105, 95% CI 0.014–0.760, p = 0.026) but a trend for worse death censored graft loss (univariate HR 2.06, 95% CI 0.91–4.65, p = 0.084).Conclusions: The incidence of erythrocytosis is falling and is likely related to greater ACEi/ARB use and possibly more antiproliferative immunosuppression. Patient survival is excellent in those with erythrocytosis, but long‐term graft survival may be compromised.
Transplant tourism to China: the impact on domestic patient‐care decisions
Authors: Biggins Scott W. , Bambha Kiran , Terrault Norah , Inadomi John , Roberts John P. , Bass Nathan 
Published: July 2009

Abstract:  Organ procurement in China has been criticized because of its reliance on executed prisoners as donors. We aimed to assess the influence of perceptions about organ procurement practices in China on domestic patient‐care decisions.Methods:  An anonymous internet administered case‐based questionnaire was used to survey a sample of healthcare professionals with affiliations to hepatology and transplantation professional societies.Results:  Of 674 completed surveys, the vast majority (93%) of the respondents were physicians, surgeons or allied transplant professionals actively caring for liver transplant patients and 81% practiced in the US. A strong majority believed procurement practices were ethically sound in the US and Europe (87% and 73%) but fare fewer believed that procurement practices were ethically sound in China (4%, p < 0.001). In case‐based questions, lack of confidence in the ethical standards of organ procurement in China predicted patient‐care decisions. The majority would provide post‐transplantation care for patients who underwent liver transplantation at another domestic center, in a foreign country and in China (90%, 78%, and 63%, respectively, p < 0.001) yet respondents who suspected unethical procurement practices in China were more reluctant to do so (p < 0.001).Conclusions:  Transplant professionals expressed concern about organ procurement practices in China which influenced their patient‐care decision‐making.
Papilledema revisited: is its pathophysiology really understood?
Authors: Killer Hanspeter E , Jaggi Gregor P , Miller Neil R 
Published: July 2009

AbstractThe term ‘papilledema’ is used to describe swelling of the optic disc that is thought or known to be associated with increased intracranial pressure (ICP) transmitted to the subarachnoid space (SAS) surrounding the optic nerve (ON). In most cases, the diagnosis of increased ICP is confirmed by lumbar puncture, the results of which are believed to represent the pressure in all of the cerebrospinal fluid (CSF) spaces. Until recently, all CSF spaces were thought to communicate freely and that CSF pressure and composition in one location were the same throughout the central nervous system (CNS) unless there was an acquired structural disturbance. However, the concept of continuous CSF flow and pressure throughout the CNS does not explain why some patients with elevated ICP do not develop papilledema, why some patients have highly asymmetrical papilledema, or why some patients with papilledema have normal ICP during 24‐hour monitoring. In addition, CSF sampling during lumbar puncture and during ON sheath fenestration demonstrates an increased concentration of lipocalin‐like prostaglandin D synthase, a substance toxic to astrocytes, in the SAS of the ON compared with that in the lumbar CSF space, and also a difference in CSF dynamics between the lumbar and ON SAS in some patients with papilledema. We therefore suggest that papilledema does not result from raised ICP alone but in some cases by compartmentation of the SAS of the ON, leading to a toxic milieu around the nerve.
Phosphodiesterase inhibitors and the eye
Authors: Kerr Nathan M , Danesh‐Meyer Helen V 
Published: July 2009

AbstractPhosphodiesterase type 5 (PDE5) inhibitors are effective oral treatments for erectile dysfunction and have become one of the most widely prescribed medications worldwide. The mechanism of action is to reduce the degradation of cyclic GMP (cGMP) potentiating the effect of nitric oxide in the corpus cavernosum and allowing erectile function to occur by consequent relaxation of penile smooth muscle. Because of the presence of PDE5 in choroidal and retinal vessels these medications increase choroidal blood flow and cause vasodilation of the retinal vasculature. The most common symptoms are a blue tinge to vision and an increased sensitivity to light. There have been reports of non‐arteritic anterior ischaemic optic neuropathy and serous macular detachment in users of PDE5 inhibitors, although a causal relationship has not been conclusively shown. Despite the role of cGMP in the production and drainage of aqueous humour these medications do not appear to alter intraocular pressure and are safe in patients with glaucoma. All PDE5 inhibitors weakly inhibit PDE6 located in rod and cone photoreceptors resulting in mild and transient visual symptoms that correlate with plasma concentrations. Psychophysical tests reveal no effect on visual acuity, visual fields or contrast sensitivity; however, some studies show a mild and reversible impairment of blue‐green colour discrimination. PDE5 inhibitors transiently alter retinal function on electroretinogram testing but do not appear to be retinotoxic. Despite the role of cyclic nucleotides in tear production there is no detrimental effect on tear film quality. Based on the available evidence PDE5 inhibitors have a good ocular safety profile.
Artificial neural networks to predict presence of significant pathology in patients presenting to routine colorectal clinics
Authors: Maslekar S. , Gardiner A. B. , Monson J. R. T. , Duthie G. S. 
Published: July 2009

AbstractAim  Artificial neural networks (ANNs) are computer programs used to identify complex relations within data. Routine predictions of presence of colorectal pathology based on population statistics have little meaning for individual patient. This results in large number of unnecessary lower gastrointestinal endoscopies (LGEs – colonoscopies and flexible sigmoidoscopies). We aimed to develop a neural network algorithm that can accurately predict presence of significant pathology in patients attending routine outpatient clinics for gastrointestinal symptoms.Method  Ethics approval was obtained and the study was monitored according to International Committee on Harmonisation – Good Clinical Practice (ICH‐GCP) standards. Three‐hundred patients undergoing LGE prospectively completed a specifically developed questionnaire, which included 40 variables based on clinical symptoms, signs, past‐ and family history. Complete data sets of 100 patients were used to train the ANN; the remaining data was used for internal validation. The primary output used was positive finding on LGE, including polyps, cancer, diverticular disease or colitis. For external validation, the ANN was applied to data from 50 patients in primary care and also compared with the predictions of four clinicians.Results  Clear correlation between actual data value and ANN predictions were found (r = 0.931; P = 0.0001). The predictive accuracy of ANN was 95% in training group and 90% (95% CI 84–96) in the internal validation set and this was significantly higher than the clinical accuracy (75%). ANN also showed high accuracy in the external validation group (89%).Conclusion  Artificial neural networks offer the possibility of personal prediction of outcome for individual patients presenting in clinics with colorectal symptoms, making it possible to make more appropriate requests for lower gastrointestinal endoscopy.
Stoma complications: a literature overview
Authors: Shabbir J. , Britton D. C. 
Published: July 2009

AbstractStoma formation is a commonly performed procedure in colorectal surgery as a part of operations performed for malignant‐ and inflammatory bowel disease. Stoma formation is a simple, but not trivial, undertaking. When performed badly, it can leave the patients with a legacy of complications such as leakage, prolapse, parastomal hernia and retraction. Various studies have reported a complication rate of 21–70%. We performed a literature search using the Medline, Ovid and Google scholar database for all the articles published between January 1980 and December 2008. The search terms used were colostomy, ileostomy, stoma, parastomal hernia, stenosis, prolapse, necrosis and complications. The following article summarizes the common complications associated with stomas.
Long‐term compliance with endoscopic surveillance for familial adenomatous polyposis
Authors: Douma K. F. L. , Bleiker E. M. A. , Aaronson N. K. , Cats A. , Gerritsma M. A. , Gundy C. M. , Vasen H. F. A. 
Published: July 2009

AbstractAim  The study assessed compliance of patients with familial adenomatous polyposis (FAP) with endoscopic surveillance.Method  In this nationwide, cross‐sectional study, individuals from FAP families registered with the Netherlands Foundation for the Detection of Hereditary Tumours were invited to complete a questionnaire on endoscopic screening experiences.Results  A total of 328 individuals were eligible for the study of whom 85 were at risk for FAP, 108 had an intact rectum after a colectomy with ileorectal anastomosis (IRA), and 135 had had a pouch following a proctocolectomy with ileoanal anastomosis (IPAA). Based on medical record data, 20% of the at‐risk group and 26% of the IRA‐group were found to be undercompliant with surveillance advice which was associated significantly with perceived self‐efficacy, use of sedatives during surveillance, pain after surveillance and low perceived benefits of surveillance (P < 0.05).Conclusion  One in five individuals at risk for FAP and one in four with a retained rectum are undercompliant with screening advice. We recommend that sedatives should be patient‐tailored for FAP individuals undergoing surveillance and that adequate pain medication be provided after endoscopy.
Downregulation of caspase‐9 is a frequent event in patients with stage II colorectal cancer and correlates with poor clinical outcome
Authors: Shen X.‐G. , Wang C. , Li Y. , Wang L. , Zhou B. , Xu B. , Jiang X. , Zhou Z.‐G. , Sun X.‐F. 
Published: July 2009

AbstractObjective  To evaluate the clinical significance of caspase‐9 mRNA expression and investigate its prognostic value in stage II colorectal cancer.Method  Quantitative real‐time RT–PCR was used to analyse caspase‐9 mRNA expression in cancer tissue and corresponding normal mucosa from 120 patients.Results  Compared with normal mucosa, the expression of caspase‐9 mRNA was found to be downregulated in cancer tissue (P = 0.001). Poorly differentiated cancer showed lower mRNA expression than cancer with greater differentiation (P = 0.031). The Kaplan–Meier survival analysis demonstrated that patients with downregulated caspase‐9 showed a worse overall survival (P = 0.012) and disease‐free survival (P = 0.022). Cox’s proportional hazards regression model confirmed that expression of caspase‐9 was the strongest prognostic factor in stage II colorectal cancer.Conclusion  The mRNA expression of caspase‐9 can be used as an independent prognostic factor for patients with stage II colorectal cancer.
Stroma‐free mass production of clinical‐grade red blood cells (RBCs) by using poloxamer 188 as an RBC survival enhancer
Authors: Baek Eun Jung , Kim Han‐Soo , Kim Ju‐Hye , Kim Nahn Ju , Kim Hyun Ok 
Published: July 2009

BACKGROUND: In vitro generation of red blood cells (RBCs) is an important alternative to donor RBCs. It was impossible, however, to generate a large quantity of RBCs due to necessity of supporting stromal cells or xenogeneic or human serum for in vitro culture, which had restrictions in safety, supplies, and expenses. In addition, the low viability of erythroblasts during terminal maturation in vitro required highly efficient production protocols. Here, we present a protocol for mass production of clinical‐grade RBCs from cord blood (CB) CD34+ cells in stroma‐free culture by using poloxamer 188 (P188), a polymer known to be cytoprotective against hydrodynamic stress.STUDY DESIGN AND METHODS: Umbilical CB CD34+ cells were cultured for 21 days in medium containing several cytokines, and roughly fibrin‐eliminated CB derived plasma was added from Day 13. To enhance the final RBC production, P188 was added from Day 13 and the cell count and viability were compared with controls lacking P188.RESULTS: Erythroid expansion between Day 17 and Day 21 was significantly higher in cultures treated with P188, with a mean of 1.5 times and maximum of 3.6 times higher expansion than in controls lacking P188. The enhanced survival resulted from increased stability of the RBC membrane and decreased fragility. The erythroid cells were enucleated up to 95% and demonstrated hematologic variables similar to those of reticulocytes.CONCLUSION: This RBC production protocol is a simple stroma‐ and serum‐free culture method ensuring enhanced viability of terminally mature erythroid cells and can be easily applicable to mass production of clinical‐grade RBCs as well as erythropoiesis research.
The Relationship between Surface Temperature, Tissue Temperature, Microbubble Formation, and Steam Pops
Authors: THOMPSON NATHANIEL , LUSTGARTEN DANIEL , MASON BRYAN , MUELLER ENKHTUYAA , CALAME JAMES , BELL STEPHEN , SPECTOR PETER 
Published: July 2009

Background: It has been proposed that microbubble (MB) monitoring can be used to safely titrate radiofrequency (RF) power. However, MB formation has been found to be an insensitive indicator of tissue temperature during RF delivery. We hypothesized that MB formation corresponds to surface—not tissue—temperature, and therefore would be an insensitive predictor of steam pops.
Methods: An in vitro bovine heart model was used to measure surface and tissue temperatures during RF delivery under conditions designed to cause steam pops. Sensitivity of type II MB (MBII) formation as a predictor of steam pops and for surface temperatures more than 80°C was calculated.
Results: Of 105 lesions delivered, 99 steam pops occurred. Twenty‐one steam pops were preceded by MBII. MBII were seen in 26 lesions, five of which were not associated with steam pop. Surface temperature at onset of MBII was 87 ± 9°C versus a tissue temperature of 78 ± 23°C (P = 0.044). Surface temperature at the time of steam pops was 71 ± 17°C versus a tissue temperature of 102 ± 17°C (P < 0.0001). The sensitivity of MBII for steam pops was 21%, and 58% for detecting surface temperature in excess of 80°C.
Conclusions: MBII correlated better with surface temperature than with tissue temperature; steam pops, on the other hand, correlated better with tissue temperature. MBII was an insensitive marker of steam pops and surface temperature in excess of 80°C. Therefore, MBII should not be used to titrate RF power.
Contact versus Noncontact Mapping for Ablation of Ventricular Tachycardia in Patients with Previous Myocardial Infarction
Authors: PRATOLA CLAUDIO , BALDO ELISA , TOSELLI TIZIANO , NOTARSTEFANO PASQUALE , PAOLO ARTALE , FERRARI ROBERTO 
Published: July 2009

Introduction: The aim of this study was to compare contact versus noncontact mapping for radiofrequency (RF) ablation of any sustained post‐myocardial infarction (MI) ventricular tachycardia (VT).
Methods: Forty patients with tolerated VT post‐MI were randomized to RF ablation with contact (group 1) or noncontact (group 2) mapping systems. In both groups ablation of tolerated VT was guided by VT activation map confirmed by concealed entrainment. When untolerated VTs were induced, ablation was performed in group 1 according to pace mapping starting from the scar border zone and in group 2 according to the VT activation map confirmed by pace mapping.
Results: No differences were seen between the groups in terms of acute success rate of clinical VT ablation (95% vs 100%, respectively; P = ns) and in the noninducibility of any VT at the end of the procedure (55% vs 85%, respectively; P = 0.08). Moreover, untolerated VTs were eliminated in 30% of group 1 versus 83.3% of group 2 patients (P < 0.05). The mean total procedural and fluoroscopy times were 236.4 ± 42.7 and 29.0 ± 7.8 minutes in group 1 and 144.5 ± 50.8 and 23.4 ± 5.8 minutes in group 2 (P < 0.001 and < 0.05, respectively). At a mean follow‐up of 15.2 ± 6.7 months no differences were seen in VT recurrences between groups, but noninducibility at the end of the procedure was predictive of freedom from recurrences (P < 0.001).
Conclusion: Both systems are useful for ablation of tolerated VT. Noncontact mapping is more effective for ablation of untolerated VT and allows the reduction of procedural and fluoroscopy times. Noninducibility at the end of the procedure seems predictive of freedom from recurrences during follow‐up.
Transmural Mapping of Myocardial Refractoriness and Endocardial Dispersion of Repolarization in an Ovine Model of Chronic Myocardial Infarction
Authors: POULIOPOULOS JIM , THIAGALINGAM ARAVINDA , EIPPER VICKI E. , CAMPBELL CRAIG , ROSS DAVID L. , KOVOOR PRAMESH 
Published: July 2009

Background:Myocardial refractoriness and repolarization is an important electrophysiological property that, when altered, increases the risk of arrhythmogenesis. These electrophysiological changes associated with chronic myocardial infarction (MI) have not been studied in detail. We assessed the influence of left ventricular (LV) scarring on local refractoriness, repolarization, and electrogram characteristics.Methods:MI was induced in five sheep by percutaneous left anterior descending artery occlusion for 3 hours. Mapping was performed at 19 ± 6 weeks post‐MI. A total of 20 quadripolar transmural needles were deployed at thoracotomy in the LV within and surrounding scar. Bipolar pacing was performed from each needle to assess the effective refractory period (ERP) of the subendocardium and subepicardium. The activation (AT) and repolarization (RT) times, and modified activation recovery interval (ARIm) were determined from endocardial unipolar electrograms recorded in sinus rhythm simultaneously from all needles. Scarring was quantified histologically and compared with electrophysiological characteristics.Results:Increased scarring corresponded with increased ERP (P < 0.01), decreased subendocardial electrogram amplitude (P < 0.001), and slope (P < 0.001). ERP did not differ between endocardium and epicardium (P > 0.05). The ARImand RT were prolonged during early myocardial activation (P < 0.001). After adjusting for AT, the RT and ARImwere prolonged in areas of scarring (P < 0.001). After adjusting for electrogram amplitude, the ARImwas prolonged in dense scar (P < 0.05).Conclusions:We confirmed histologically that scarring contributes to prolongation of repolarization, increased refractoriness, and reductions in conduction and voltage post‐MI. Prolongation of repolarization may be further augmented when local activation is earliest or electrogram voltage is decreased within scar.
Psychogenic Syncope? A Cautionary Note
Authors: KANJWAL KHALIL , KANJWAL YOUSUF , KARABIN BEVERLY , GRUBB BLAIR P. 
Published: July 2009

Introduction: In some patients with recurrent syncope, the etiology may remain unclear despite extensive evaluation. These patients may sometimes be labeled as having a “psychogenic” cause for their syncope.
Methods: We report on three patients with recurrent unexplained syncope (despite extensive evaluation) who were labeled as having a psychogenic cause for their events. In each patient following placement of an implantable loop recorder, their syncopal events were found to be due to periods of prolonged asystole and/or complete heart block. One patient had prolonged asystole for 44 seconds. In each patient, episodes of syncope were eliminated following permanent pacemaker implantation.
Conclusion: We conclude that physicians should exercise great caution before labeling any patient's syncope as psychogenic and that prolonged monitoring may be necessary to exclude a potential cardiac rhythm‐related etiology.