bluuebunny/crossref_metadata_2025_split huggingface dataset:
Surgical Treatment of Barrett’s Esophagus: 1980‐2003
Authors: Csendes Attila 
Published: March 2004

AbstractBarrett’s esophagus is a complication of long‐standing gastroesophageal reflux and can be a premalignant condition. The goals of surgical treatment, which were well summarized by DeMeester, have been increased and more detailed by us. They consist of (1) controlling symptoms of gastroesophageal reflux disease; (2) abolishing acid and duodenal reflux into the esophagus; (3) preventing or eliminating the development of complications; (4) preventing extension of or an increase in the length of intestinal metaplasia; (5) inducing regression of intestinal metaplasia to the cardiac mucosa; and (6) preventing progression to dysplasia, thereby inducing regression of low‐grade dysplasia and avoiding the appearance of an adenocarcinoma. We have reviewed 25 articles in the English‐language literature published from 1980 to 2003 dealing specifically with the surgical treatment of Barrett’s esophagus. In most of these papers too few patients were included, the follow‐up was less than 60 months, and the clinical success deteriorated with time. Acid reflux persists after surgery in nearly 35% of Barrett’s esophagus patients; and at 10 years after surgery duodenal reflux is present in 95%. Peptic ulcer, stricture, and erosive esophagitis are present in 15% to 30% late after surgery, and in 16% there is progression of the intestinal metaplasia. There is the appearance of low‐grade dysplasia in 6.0% and adenocarcinoma in 3.4%, and there is regression of low‐grade dysplasia in 45.0%. These results challenge the arguments supporting antireflux surgery for patients with Barrett’s esophagus: The clinical results are not optimal, no long‐lasting effect has been demonstrated, and it does not prevent the appearance of dysplasia or adenocarcinoma. An excellent alternative is acid suppression and a duodenal diversion procedure, which has had 91% clinical success for more than 5 years. This regimen has almost eliminated acid and duodenal reflux, and there has been no progression to dysplasia or adenocarcinoma. Moreover, in 60% of the patients with low‐grade dysplasia, regression to nondysplastic mucosa has occurred.
Problems and Prospects of Managing Thoracic Aortic Aneurysm at the Nnamdi Azikiwe University Teaching Hospital, Nnewi, Nigeria
Authors: Chianakwana Gabriel U. , Odike Maxy A.C. , Nwofor Alexander M.E. 
Published: March 2004

AbstractThe objective of this report is to highlight the problems encountered in managing thoracic aortic aneurysm in a third‐generation teaching hospital serving a purely rural community in the heartland of Anambra State, in the southeastern part of Nigeria. This report also proffers solutions aimed at assisting in providing better care for patients afflicted with this condition. From time to time, patients present with vascular diseases, including aneurysm, but the condition is only occasionally suspected and sparingly investigated. This is a report of two cases within the setting of the Nnamdi Azikiwe University Teaching Hospital (NAUTH), Nnewi Nigeria. After the death of these two patients, one of whom was a member of the staff of the hospital, post mortem examinations revealed that they had died of ruptured thoracic aortic aneurysm. Their medical records were retrieved from the Medical Records Department and reviewed with the aim of analyzing their clinical features and management in the light of the unexpected post‐mortem examination results. The survey of the patient records revealed that the diagnosis of thoracic aortic aneurysm was not suspected in either patient even though both had symptoms pointing to this condition. The staff member was a 55‐year old man and the other patient was a 31‐year old woman in her 30thweek of pregnancy. We conclude by drawing the attention of medical practitioners in our community to the fact that thoracic aortic aneurysms are probably more common than we thought. Only a high index of suspicion will lead to clinical diagnosis and treatment.
Aging and Wound Healing
Authors: Gosain Ankush , DiPietro Luisa A. 
Published: March 2004

AbstractImpaired wound healing in the elderly presents a major clinical and economic problem. With the aging population growing in both number and percentage, the importance of understanding the mechanisms underlying age‐related impairments in healing is increased. Normal skin exhibits characteristic changes with age that have implications for wound healing. Additionally, the process of wound healing is altered in aged individuals. Although historically healing in the aged was considered defective, there is now consensus that healing in the elderly is delayed but the final result is qualitatively similar to that in young subjects.
Redox Processes Underlying the Vascular Repair Reaction
Authors: Leite Paulo F. , Liberman Marcel , Sandoli de Brito Fábio , Laurindo Francisco R.M. 
Published: March 2004

AbstractAccumulating evidence indicates that vascular dysfunction in atherosclerosis, hypertension, and diabetes is either caused by or accompanied by oxidative stress in the vessel wall. In particular, the role of redox processes as mediators of vascular repair and contributors to post‐angioplasty restenosis is increasingly evident. Yet the pathophysiology of such complex phenomena is still unclear. After vascular injury, activation of enzymes such as NADPH oxidase leads to a marked increase in superoxide generation, proportional to the degree of injury, which rapidly subsides. Such early superoxide production is significantly greater after stent deployment, as compared to balloon injury. Recent data suggest the persistence of low levels of oxidant stress during the vascular repair reaction in neointimal and medial layers. Despite the compensatory increase in expression of iNOS and nNOS, nitric oxide bioavailability is reduced because of increased reaction rates with superoxide, yielding as by‐products reactive nitrogen/oxygen species that induce protein nitration. Concurrently, the activity of vascular superoxide dismutases exhibits a sustained decrease following injury. This decreased activity appears to be a key contributor to vasoconstrictive remodeling and a major determinant of the occurrence of nitrative/oxidative stress. Replenishment of superoxide dismutase (SOD), as well as treatment with vitamins C and E or the lipid‐lowering drug probucol and its analogs, led to decrease in constrictive remodeling and improved vessel caliber. Better understanding of the redox pathophysiology of vascular repair should help clarify the pathogenesis of many other vascular conditions and may provide novel therapeutic strategies to prevent vascular lumen loss.
Comparative investigation of two rotary nickel–titanium instruments: ProTaper versus RaCe. Part 2. Cleaning effectiveness and shaping ability in severely curved root canals of extracted teeth
Authors: Schäfer E. , Vlassis M. 
Published: March 2004

AbstractAim  To determine the cleaning effectiveness and shaping ability of ProTaper and RaCe nickel–titanium rotary instruments during the preparation of curved root canals in extracted human teeth.Methodology  A total of 48 root canals of mandibular and maxillary molars with curvatures ranging between 25° and 35° were divided into two groups of 24 canals each. Based on radiographs taken prior to instrumentation with the initial instrument inserted into the canal, the groups were balanced with respect to the angle and the radius of canal curvature. Canals were prepared using a crown‐down preparation technique. After each instrument, the root canals were flushed with a 2.5% NaOCl solution and at the end of instrumentation with NaCl. Using pre‐ and post‐instrumentation radiographs, straightening of the canal curvatures was determined with a computer image analysis program. After splitting the roots longitudinally, the amount of debris and smear layer was quantified on the basis of a numerical evaluation scale, using a scanning electron microscope (SEM). The data established for scoring the debris and the smear layer were separately recorded and analysed statistically using the Wilcoxon test.Results  Two ProTaper and three RaCe instruments fractured; there was no significant difference between instrument types (P > 0.05). Completely clean root canals were never observed. For debris removal, RaCe files achieved significantly better results (P < 0.001) than ProTaper instruments. The results for remaining smear layer were similar and not significantly different (P > 0.05). RaCe instruments maintained the original canal curvature significantly better (P < 0.05) than ProTaper instruments. No significant differences were detected between the instruments (P > 0.05) for the time taken to prepare the canals.Conclusions  Under the conditions of this study, RaCe instruments resulted in relatively good cleaning and maintained the original curvature significantly better than ProTaper did.
A comparison of instrument‐centering ability within the root canal for three contemporary instrumentation techniques
Authors: Song Y. L. , Bian Z. , Fan B. , Fan M. W. , Gutmann J. L. , Peng B. 
Published: March 2004

AbstractAim  To study and compare Great Taper (GT) hand files using a reversed balanced force technique, nickel–titanium (NiTi)flex files with a balanced force technique and stainless steel (SS) K‐type files using a step‐back technique.Methodology  Forty‐eight extracted mandibular premolar teeth with single root canals having curvatures between 15 and 45° were prepared using a modified Bramante model and randomly divided into three groups. The teeth were cross‐sectioned at 2, 6 and 10 mm from the working length. Preoperative images of canals at three levels were captured at 20× magnification using a stereomicroscope. Canals in each group were, respectively, prepared to an apical size .10 GT file with 0.2 mm tip diameter, size 30 NiTiflex file and size 30 SS K‐file. The GT file was used in a reversed balanced force technique, the NiTiflex file was used in a balanced force technique, and the SS K‐file was used in a step‐back technique. Postoperative canals were imaged under the conditions same as those for the preoperative canals. The postoperative images were superimposed over the preoperative images using software photoshop 6.0. The ability to maintain the instrument in the central axis of the canal and the deviation from the central canal axis were determined and compared by statistical analysis, along with the assessment of the amount of dentine removed.Results  At apical level, the centering ratio, the distance of transportation and the dentine removed in GT and NiTiflex groups were significantly less than those in SS group (P < 0.01), but no statistical differences were found between the two NiTi groups. At other levels, there were no substantial differences amongst the groups.Conclusions  Compared with SS K‐files, GT hand files and NiTiflex files remain better centered and produce significantly less transportation in curved canals.
Toxicity of concentrated sodium hypochlorite used as an endodontic irrigant
Authors: Gernhardt C. R. , Eppendorf K. , Kozlowski A. , Brandt M. 
Published: March 2004

AbstractAim  To present a clinical case that illustrates the toxicity of concentrated sodium hypochlorite (NaOCl) on vital tissues.Summary  The severe clinical consequences of extruding concentrated NaOCl into the periradicular tissues during root canal irrigation are described. After diagnosis of external resorption in tooth 34, endodontic treatment was initiated. Following irrigation with a concentrated NaOCl solution, a rapidly developing swelling and haematoma were visible. During the next few days, an extensive bruise and local necrosis of the oral mucosa developed. After healing of the involved tissues, the canal was prepared and obturated. At this time, no clinical symptoms remained.Key learning points

The use of concentrated NaOCl as a root canal irrigant might cause severe clinical problems when extruded into vital tissues.
The present report confirms the known toxicity of NaOCl to soft tissues following inadvertent extrusion.
To avoid extrusion, it is always prudent to confirm the length and integrity of the root canal system before irrigating with concentrated solutions.
Role of Keratinocytes in Antigen Presentation and Polarization of Human T Lymphocytes
Authors: Banerjee G. , Damodaran A. , Devi N. , Dharmalingam K. , Raman G. 
Published: March 2004

AbstractAllergic contact dermatitis is a T‐cell‐mediated inflammatory skin disease in which interaction between skin keratinocytes and migrating T lymphocytes may play a critical part. In this study, the role of keratinocytes as allergen‐/antigen‐presenting cells (APCs) leading to activation of T lymphocytes is investigated using a human epidermal cell line A431. It is known that cultured cells do not express human leucocyte antigen (HLA) and hence can be used as APCs independent of HLA profile of both APCs and T cells from human volunteers. This cell line responded to common allergens and irritants by inducing or upregulating the cell‐surface expression of HLA‐DR, and intercellular adhesion molecule‐1 and B7 mRNA transcripts in keratinocytes. In addition, allergen‐primed A431 cells also induced allergen‐specific proliferation of human T lymphocytes in cocultures. Anti‐HLA‐DR, interleukin‐1α (IL‐1α) antibodies and lysosomotropic agent chloroquine inhibited the proliferation. Allergens also upregulated cytokines IL‐1α, granulocyte–macrophage colony‐stimulating factor, Gro‐α and IL‐12 in keratinocytes. Further, keratinocytes activated by allergens induced polarization of activated T lymphocytes to the Th1 phenotype.
DAILY HEMODIALYSIS—SELECTED TOPICS: Quantifying Daily Hemodialysis
Authors: Depner Thomas A. , Bhat Adarsh 
Published: March 2004

ABSTRACTNearly all published reports and clinical studies of hemodialysis solute kinetics are confined to thrice‐weekly dialysis schedules. Over the past 40 years, clinical experience with dialysis treatments given three times per week has expanded enormously, but it was not until the Hemodialysis (HEMO) study results were revealed that nephrologists became fully aware of the limits of usefulness of infrequent dialysis. In light of continued reports of improved quality of life and survival with daily dialysis, it appears that the limits of thrice‐weekly dialysis may be extended when treatments are given more often. Analysis of solute kinetics during and between dialyses supports the notion that a more frequent schedule delivers more efficient dialysis and that methods can be developed to allow a comparison of risks among patients treated 3–7 days per week. One such method, based on the concept of solute seclusion, suggests that at the currently established minimum standard dose, approximately 50% of the improvement in solute control afforded by seven treatments per week is achieved by increasing the frequency to four treatments per week. The same model shows that seven treatments per week afford an improvement in solute control that is approximately 80% as effective as continuous dialysis. These conclusions are similar to those derived from a completely different model based on peak concentration toxicity. Neither of these models has been clinically tested, so caution must be advised when treating individual patients.
DAILY HEMODIALYSIS—SELECTED TOPICS: Quality of Life and Daily Hemodialysis
Authors: Kutner Nancy G. 
Published: March 2004

ABSTRACTPreliminary findings indicate that daily hemodialysis positively impacts patients’ energy/fatigue and other uremic and intradialytic symptoms. In addition to improvements in perceived symptoms, improvements in patients’ perceived physical and psychosocial functioning have been reported. These findings have come from small series of patients, however, and may reflect an increased attention effect. Confirmation of preliminary findings and identification of changes in other quality of life outcomes await an adequately powered randomized clinical trial. Sleep quality, sexual functioning, and cognitive functioning are quality of life dimensions that may be impacted by daily hemodialysis but about which there is limited information in the preliminary data that exist. Understanding relationships among different levels of quality of life outcomes associated with daily hemodialysis requires consideration of emotional and psychological variables such as burden, depression, and satisfaction with care that may intervene between treatment and the quality of life outcomes that patients report. Deriving health utilities relevant to patient experience on different daily hemodialysis therapies, analyzing longitudinal quality of life outcomes reported by patients on daily hemodialysis, and investigating the effectiveness of daily hemodialysis for specific patient subgroups are research agendas that can provide information needed to facilitate treatment decision making in which quality of life has an important role.
DAILY HEMODIALYSIS—SELECTED TOPICS: Cardiovascular Effects of Frequent Intensive Hemodialysis
Authors: Chan Christopher T. 
Published: March 2004

ABSTRACTCardiovascular disease remains the leading cause of morbidity and mortality for patients with end‐stage renal disease (ESRD). Frequent intensive hemodialysis (short daily hemodialysis [2 hours per session, six sessions per week] and nocturnal home hemodialysis [6 hours per session, five to six sessions per week]) has recently gained increasing popularity as an alternative to conventional hemodialysis (4 hours per session, three sessions per week). There is an emerging body of evidence that frequent intensive hemodialysis offers superior uremic toxin clearance, blood pressure control, and other cardiovascular outcomes. The goals of the present review are to systematically evaluate the available evidence in blood pressure control and cardiovascular outcomes in ESRD and the achievable changes after converting from conventional dialysis to frequent intensive hemodialysis, and to provide possible physiological explanations to account for these important changes of potent markers of adverse events in this patient population.
DAILY HEMODIALYSIS—SELECTED TOPICS: Predicting Treatment Dose for Novel Therapies Using Urea Standard Kt/V
Authors: Leypoldt John K. , Jaber Bertrand L. , Zimmerman Deborah L. 
Published: March 2004

ABSTRACTCalculation of urea standard Kt/V (stdKt/V) as a dose measure for guiding novel hemodialysis or hemofiltration therapy prescription is complex since this parameter depends on the magnitude of posttreatment urea rebound. We propose here a two‐step procedure for calculating urea stdKt/V from single‐pool urea Kt/V values (spKt/V) determined from serum urea concentrations in pretreatment and posttreatment blood samples. First, the dependence of urea stdKt/V on equilibrated Kt/V (eKt/V) was derived from a fixed‐volume single‐pool model. Second, an empirical equation for predicting urea eKt/V from urea spKt/V values was determined using multiple linear regression and available data during 4‐hour hemodialysis, 2‐hour hemodialysis, and 2‐hour hemofiltration treatments. This empirical (rate/dose) equation is likely more robust for novel therapies than other equations derived from only data during conventional (4‐hour) hemodialysis treatments. The combination of these formulas allowed construction of nomograms for calculating urea stdKt/V from spKt/V during novel therapies. These principles were further illustrated by calculating the predicted treatment dose for daily (six times per week) hemofiltration therapy required to achieve a given urea stdKt/V.
Stress‐ as Well as Suckling‐Induced Prolactin Release is Blocked by a Structural Analogue of the Putative Hypophysiotrophic Prolactin‐Releasing Factor, Salsolinol
Authors: Bodnár I. , Mravec B. , Kubovcakova L. , Tóth E. B. , Fülöp F. , Fekete M. I. K. , Kvetnansky R. , Nagy G. M. 
Published: March 2004

AbstractProlactin is secreted from the anterior lobe of the pituitary gland in response both to suckling and to stress. We recently observed that 1‐methyl‐6,7‐dihydroxy‐1,2,3,4‐tetrahydroisoquinoline (salsolinol), produced in the neurointermediate lobe of the pituitary gland, as well as in the medial basal hypothalamus, can selectively release prolactin from the anterior pituitary. Therefore, it has been proposed that salsolinol is a putative endogenous prolactin‐releasing factor (PRF). Here, we report that one structural analogue of salsolinol, 1‐methyl‐3,4‐dihydroisoquinoline (1MeDIQ), can block salsolinol‐induced release of prolactin, but does not affect prolactin release in response to thyrotropin releasing hormone (TRH), α‐methyl‐p‐tyrosine (αMpT) (an inhibitor of tyrosine hydroxylase), domperidone (a D2 dopamine receptor antagonist), or 5‐hydroxytryptophan (5‐HTP), a precursor of serotonin). 1MeDIQ profoundly inhibited suckling‐, immobilization‐, as well as formalin‐stress induced prolactin release without any influence on corticosterone secretion. The 1MeDIQ‐induced reduction in prolactin response to immobilization stress was dose‐dependent. These results suggest that salsolinol can play a pivotal role in the regulation of prolactin release induced by either physiological (suckling) or environmental (stress) stimuli.
Somatostatin is a specific inhibitor of SDF-1α-induced T cell infiltration
Authors: TALME T , IVANOFF J , SUNDQVIST K G 
Published: March 2004

SUMMARYThe chemokine stromal cell-derived factor 1α (SDF-1α) is a potent stimulator of T cell infiltration into three-dimensional type I collagen matrices as demonstrated using T cells freshly isolated from blood and an activated T cell clone. The neuropeptide somatostatin selectively inhibits SDF-1α induced T cell infiltration by the same T cells including CD4 as well as CD8 positive cells, while somatostatin does not inhibit ‘spontaneous’ T cell infiltration. A number of other neuropeptides and opioids do not inhibit SDF-1α-induced T cell infiltration, indicating that the inhibitory effect is somatostatin-specific. The neuropeptide antagonist cyclosomatostatin abrogated the inhibitory effect of somatostatin on T cell infiltration, indicating that the effect of somatostatin is mediated via specific somatostatin receptors. Somatostatin does not inhibit SDF-1α-induced T cell attachment to the collagen substrate, which indicates that this neuropeptide specifically inhibits the process of chemokine-induced T cell penetration and migration through the collagen.
A method for exact reliability of consecutive2‐out‐of‐(r, r)‐from‐(n, n):F systems
Authors: Higashiyama Y. 
Published: March 2004

AbstractA new reliability model, consecutive 2‐out‐of‐(r, r)‐from‐(n, n):F model, is proposed. The consecutive 2‐out‐of‐(r, r)‐from‐(n, n):F system consists of a square grid of side n (containing n2 components) such that the system fails if and only if there is at least one square of side r which includes among them at least two failed components. For i.i.d. case an algorithm is given for computing the reliability of the system. The reliability function can be expressed by the number of 0–1 matrices having no two or more 0s at any square of side r.