bluuebunny/crossref_metadata_2025_split huggingface dataset:
Trinucleotide expansions leading to an extended poly‐l‐alanine segment in the poly (A) binding protein PABPN1 cause fibril formation
Authors: Scheuermann Till , Schulz Barbe , Blume Alfred , Wahle Elmar , Rudolph Rainer , Schwarz Elisabeth 
Published: November 2003

AbstractThe nuclear poly(A) binding protein (PABPN1) stimulates poly(A) polymerase and controls the lengths of poly(A) tails during pre‐mRNA processing. The wild‐type protein possesses 10 consecutive Ala residues immediately after the start methionine. Trinucleotide expansions in the coding sequence result in an extension of the Ala stretch to maximal 17 Ala residues in total. Individuals carrying the trinucleotide expansions suffer from oculopharyngeal muscular dystrophy (OPMD). Intranuclear inclusions consisting predominantly of PABPN1 have been recognized as a pathological hallmark of the genetic disorder. To elucidate the molecular events that lead to disease, recombinant PABPN1, and N‐terminal fragments of the protein with varying poly‐l‐alanine stretches were analyzed. As the full‐length protein displayed a strong tendency to aggregate into amorphous deposits, soluble N‐terminal fragments were also studied. Expansion of the poly‐l‐alanine sequence to the maximal length observed in OPMD patients led to an increase of α‐helical structure. Upon prolonged incubation the protein was found in fibrils that showed all characteristics of amyloid‐like fibers. The lag‐phase of fibril formation could be reduced by seeding. Structural analysis of the fibrils indicated antiparallel β‐sheets.
Heat‐induced denaturation and aggregation of ovalbumin at neutral pH described by irreversible first‐order kinetics
Authors: Weijers Mireille , Barneveld Peter A. , Cohen Stuart Martien A. , Visschers Ronald W. 
Published: November 2003

AbstractThe heat‐induced denaturation kinetics of two different sources of ovalbumin at pH 7 was studied by chromatography and differential scanning calorimetry. The kinetics was found to be independent of protein concentration and salt concentration, but was strongly dependent on temperature. For highly pure ovalbumin, the decrease in nondenatured native protein showed first‐order dependence. The activation energy obtained with different techniques varied between 430 and 490 kJ•mole−1. First‐order behavior was studied in detail using differential scanning calorimetry. The calorimetric traces were irreversible and highly scan rate‐dependent. The shape of the thermograms as well as the scan rate dependence can be explained by assuming that the thermal denaturation takes place according to a simplified kinetic process where N is the native state, D is denatured (or another final state) and k a first‐order kinetic constant that changes with temperature, according to the Arrhenius equation. A kinetic model for the temperature‐induced denaturation and aggregation of ovalbumin is presented. Commercially obtained ovalbumin was found to contain an intermediate‐stable fraction (IS) of about 20% that was unable to form aggregates. The denaturation of this fraction did not satisfy first‐order kinetics.
Studying the roles of W86, E202, and Y337 in binding of acetylcholine to acetylcholinesterase using a combined molecular dynamics and multiple docking approach
Authors: Kua Jeremy , Zhang Yingkai , Eslami Angelique C. , Butler John R. , McCammon J. Andrew 
Published: November 2003

AbstractA combined molecular dynamics simulation and multiple ligand docking approach is applied to study the roles of the anionic subsite residues (W86, E202, Y337) in the binding of acetylcholine (ACh) to acetylcholinesterase (AChE). We find that E202 stabilizes docking of ACh via electrostatic interactions. However, we find no significant electrostatic contribution from the aromatic residues. Docking energies of ACh to mutant AChE show a more pronounced effect because of size/shape complementarity. Mutating to smaller residues results in poorer binding, both in terms of docking energy and statistical docking probability. Besides separating out electrostatics by turning off the partial charges from each residue and comparing it with the native, the mutations in this study are W86F, W86A, E202D, E202Q, E202A, Y337F, and Y337A. We also find that all perturbations result in a significant reduction in binding of extended ACh in the catalytically productive orientation. This effect is primarily caused by a small shift in preferred position of the quaternary tail.
Solution NMR structure of the 30S ribosomal protein S28E from Pyrococcus horikoshii
Authors: Aramini James M. , Huang Yuanpeng J. , Cort John R. , Goldsmith‐Fischman Sharon , Xiao Rong , Shih Liang‐Yu , Ho Chi K. , Liu Jinfeng , Rost Burkhard , Honig Barry , Kennedy Michael A. , Acton Thomas B. , Montelione Gaetano T. 
Published: November 2003

AbstractWe report NMR assignments and solution structure of the 71‐residue 30S ribosomal protein S28E from the archaean Pyrococcus horikoshii, target JR19 of the Northeast Structural Genomics Consortium. The structure, determined rapidly with the aid of automated backbone resonance assignment (AutoAssign) and automated structure determination (AutoStructure) software, is characterized by a four‐stranded β‐sheet with a classic Greek‐key topology and an oligonucleotide/oligosaccharide β‐barrel (OB) fold. The electrostatic surface of S28E exhibits positive and negative patches on opposite sides, the former constituting a putative binding site for RNA. The 13 C‐terminal residues of the protein contain a consensus sequence motif constituting the signature of the S28E protein family. Surprisingly, this C‐terminal segment is unstructured in solution.
SCREAMING AS A STRATEGY TO REDUCE THE PREDATION RISK INCURRED BY BEGGING?
Authors: Roulin  
Published: November 2003

AbstractFollowing the theory of parent-offspring conflict parents request from their offspring an honest signal of food requirement to optimally adjust feeding rate. For this purpose, offspring display a highly informative signalling system, begging vocalisation, for which the conspicuousness to predators maintains honesty, since only hungry offspring are willing to take this risk. The risk of predation incurred by begging activities challenges our understanding of how begging vocalisation could evolve towards a high degree of noisiness. A solution to this apparent paradox resides in the possibility that alongside the evolution of begging, birds also evolved strategies that reduce the risk of being depredated. Following the ornithological literature nestlings scream in the presence of a predator to frighten it, induce parents to rescue them and siblings to flee from the nest and hide in the vegetation. I therefore propose the hypothesis that nestling screaming behaviour evolved as a means of reducing the risk of predation incurred by conspicuous begging. Comparative analyses supported the prediction postulating that species in which nestlings scream in the presence of a predator produce begging calls that are more conspicuous to predators than calls of non-screaming species. This suggests that the predation cost of begging lies not only in terms of predation per se but also in the requirement of anti-predator strategies.
DIFFERENT LEVELS OF VARIABILITY IN THE FEMALE SONG OF WILD SILVERY GIBBONS (HYLOBATES MOLOCH)
Authors: Dallmann Robert , Geissmann Thomas 
Published: November 2003

AbstractGibbon songs are known to include species- and sex-specific characteristics. It has been suggested frequently that these songs also exhibit a high degree of individuality, but quantifying individuality has rarely been attempted. Because the statistical methods used in earlier studies were highly dependent on sample size (Kruskal-Wallis one-way analysis of variance by ranks), it was not possible to compare results among studies directly. We introduce a mean pairwise difference (MPD) of scaled variables in order to quantify great-call variability and individuality. Because of its construction as simple normalised difference, the MPD is largely independent of sample size. This makes it possible to compare results directly with those of other studies on other populations or species. Even various levels of variability (intra- vs. inter-individual, intra- vs. inter-population variability) can be determined and compared with this method. In addition, the MPD can be calculated independently for any acoustic variable. This opens up a broad variety of research options in the area of comparative analysis of acoustic communication. For instance, variability in various parts of a phrase, in various parts of a song bout, in various contexts or in various seasons can be compared, and this is possible even if the variables under comparison are not the same. As an example we analysed female great-call phrases of wild silvery gibbons in Java (Indonesia). We found that inter-individual variability is significantly higher than intra-individual variability. This implies that females can be distinguished by their great-calls, although this was not examined during the present study. Additionally, variability of female songs was found to be significantly lower within one population than among any two populations. The various sections of the great-call differ in their variability. The first half of the great-call (excluding the introductory note) shows the highest potential for individual recognition.
Reforms of Administrative Law in the PRC and Vietnam: The Possible Role of the Legal Tradition
Authors: Buhmann Karin 
Published: November 2003

AbstractThe article takes its point of departure in administrative law and good governance as possible avenues for increased implementation of rights, including human rights. The author discusses the role that pre-modern East Asian ideas on governance and pre-modern administrative law and institutions for monitoring the executive's use of power may play for the substance and focus of the reforms of administrative law that have been undertaken in the late 20th century in the People's Republic of China (PRC) and in Vietnam. The article discusses the possible influence of ideas and institutions inspired by Confucianism and the School of Legalism, including such features as a meritocratic civil service, institutions for monitoring the executive and for dealing with complaints, instrumental use of law, and use of rewards, punishments and instruction to achieve the aims of the law. The author compares the prevalence of the features of pre-modern China and Vietnam with elements in legislation and institutions implemented under the late 20th century reform processes in the PRC and Vietnam. The article concludes that the legacy of the pre-modern system of administrative law and governance and related institutions appears to play a role in the modern reform process that is more than accidental, and that this legacy results in a relatively strong emphasis on a principle of legality in the legislation implemented under the reforms and in a relatively weaker emphasis on the principle of equality. The article suggests that features of the premodern legacy, especially the emphasis on exercise of executive power in accordance with law, may be explored as providing potential for contributing to an increased quality of public administration and an increased implementation of rule of law and specific rights, including human rights and rights of relevance to trade and investment. It is also suggested that these features of the pre-modern system may be explored by the development community and international organizations as potential for creating ownership and sustainability of governance and law reforms that are of interest to external partners of the PRC and Vietnam.
Relationships between Gastric Development and Anatomic Bases of Radical Surgery for Cancer
Authors: Borghi Felice , Gattolin Andrea , Bogliatto Fabrizio , Garavoglia Marcello , Levi Alessandro Cesare 
Published: November 2003

Abstract
The aim of this study was to determine with all possible accuracy the processes of embryologic development of the stomach and its lymphatics in order to confirm their supposed link with the modern anatomic bases of gastric cancer surgery.
The knowledge of the anatomic behavior of the peritoneal folds and of the lymphatic drainage of the stomach is, in fact, considered the essential basis for the comprehension of the oncologic dissection of the stomach. The study was based on reconstruction of serial histologic sections of 9 human embryos and 8 human fetuses regarding the mesogastric area, as well as anatomic microdissection of 2 9‐month fetuses. The proximal part of the stomach is not involved in the rotation mechanism of the other portions; the lesser sac development follows cranial migration of the spleen; the cardiac (pars cardiaca gastris) area is in continuity with the zone of paraaortic lymph node development; lateral and posterior lymph nodes of the hepatoduodenal ligament do not take origin in the dorsal mesogastrium: they develop together with the common bile duct and the ventral pancreas inside the mesoduodenum; the fusion of the dorsal mesogastrium and the gastric fundus with the posterior abdominal wall appears late in development.
The embryologic study of the mesogastric area clarifies the real mechanism of development of the stomach and its lymphatic pathways with some differences from classic reports; these results agree with the more recent modification of the lymph nodes classification used in the radical treatment of gastric cancer.
Long‐term Results of Patients with pT2 Rectal Cancer Treated with Radiotherapy and Transanal Endoscopic Microsurgical Excision
Authors: Lezoche Emanuele , Guerrieri Mario , Paganini Alessandro M. , Feliciotti Francesco 
Published: November 2003

AbstractAnterior resection and abdomino‐perineal resection are the surgical techniques used most frequently in the treatment of rectal cancer. Local recurrence rates of 10% to 14% are described after these conventional procedures. Preoperative neoadjuvant radiotherapy reduces local failure. Because local excision techniques can be applied to treat early rectal cancer in selected patients, we evaluated the results of preoperative high‐dose radiotherapy and transanal endoscopic microsurgical excision (TEM) in patients with T2 rectal cancer. All patients underwent preoperative irradiation with 5,040 cGy, divided over 5 weeks. Fourty days after completion of radiotherapy, the patients underwent complete full‐thickness local excision of the rectal lesion including adjacent perirectal fat by TEM. The patients were followed for up to 8 years. Thirty‐five patients, with pT2 rectal cancer as determined by pathological examination of the surgical specimen were enrolled in the present study. The tumors were responsive to preoperative radiotherapy in 82.8% of cases. No intraoperative complications and no conversion to open surgery were observed. No major complications and no mortality occurred during the 60‐day postoperative period. Minor postoperative complications were observed in 5 patients (14.3%). The median follow‐up of the patients was 38 months (range 24 to 96 months). One local recurrence (2.85%) was noted. The probability of surviving at 96 months after completion of treatment was 83%. Local excision by TEM combined with preoperative high‐dose radiotherapy can achieve results similar to those observed after conventional surgery in patients with pT2 rectal cancer.
Management of Appendiceal Masses in a Peripheral Hospital in Nigeria: Review of Thirty Cases
Authors: Okafor Pius I.S. , Orakwe Jideofor C. , Chianakwana Gabriel U. 
Published: November 2003

AbstractThe objective of this work was to conduct a truly rural‐based study to evaluate, from our own rural data devoid of influence from urban‐based studies, the management of appendiceal masses in a typical peripheral hospital in Nigeria. The study aimed to highlight the results of neglected appendicitis in our community and the occasional difficulty of making a correct preoperative diagnosis. It also sought to draw the attention of the health care practitioner in our community to the importance of continued enlightenment of the people regarding the need to seek medical treatment early. This was a retrospective study, with the setting at St. Victoria Specialist Hospital, Ekwulobia, Anambra State, Nigeria, a rural hospital serving its community. A series of 30 patients who were managed for an appendiceal mass between January 1, 1992 and December 31, 2001, a 10‐year period, were included in the study. We identified the cases by reviewing the surgical register. The relevant case notes were retrieved from the Records Department. The following data were extracted for each patient: age and sex; how early the patient presented; the history and presentation of the patient; whether the diagnosis was made before or during surgery; the treatment modality; length of hospital stay; and outcome. The results showed that 13 patients (43.3%) presented more than 1 week after the onset of symptoms. The age range was 15 to 60 years (average 27 years); 13 patients (43.3%) were in the age range of 40–49 years. Twenty men and ten women were treated, giving a male/female ratio of 2:1. The main clinical features were fever, anorexia, pain, tenderness, and a palpable mass in the right iliac fossa. The problem was diagnosed before surgery in 23 patients (76.7%) and during surgery in 7 (23.3%). Treatment modalities were conservative + interval appendectomy in 18 patients (60%); open and close + conservative + interval appendectomy in 3 patients (10%); immediate appendectomy without burying the stump in 2 cases (6.7%); right hemicolectomy (in one 40‐year‐old woman and one 55‐year‐old man); and incision and drainage of an appendiceal abscess in 5 patients (16.7%). No deaths were recorded. The study showed that appendical masses are most prevalent during the fifth decade of life and are rare before age 10 and after age 60. More men are affected than women, and most cases can be diagnosed before surgery, although some patients must await more sophisticated diagnostic tools or surgical exploration for diagnosis.
Transitional Cell Carcinoma in Renal Transplant Recipients
Authors: Kao Yu‐Lin , Ou Yen‐Chuan , Yang Chi‐Rei , Ho Hao‐Chung , Su Chung‐Kuang , Shu Kuo‐Hsiung 
Published: November 2003

AbstractRenal transplantation (RTx) recipients have a high incidence of cancer, including transitional cell carcinoma (TCC). Posttransplantation urologic malignancies still present a challenge for transplant surgeons. Using the Dialysis and Transplant Registry of Taichung Veterans General Hospital, a total of 55 cancers were diagnosed in 52 RTx recipients between May 1983 and September 2001. Of these, 24 RTx recipients developing TCC were identified and presented the distinctly high percentage (43.6%) of TCC that were malignancies after RTx in Taiwan. The mean time between transplantation and initial diagnosis was 46 months in our series. Painless hematuria with pyuria is the most common mode of presentation. Transitional cell carcinoma of RTx recipients had multiple foci. Moreover, synchronous TCC in bilateral upper urinary tracts were confirmed in 9 (41%) recipients. The pathologic status of disease is invasive at diagnosis (pTa: 2, pT1: 7, pT2: 4, pT3: 6, pT4: 2, graft metastasis: 1 and distant metastasis: 2). Disseminated metastasis occurred in 6 recipients, all of whom died of their disease within 16 months. Five recipients received adjuvant chemotherapy and retained stable renal function. We conclude that RTx recipients have a markedly increased incidence of TCC in Taiwan, and that prophylactic bilateral nephroureterectomy of native kidneys with bladder cuff excision can be performed simultaneously in RTx recipients with TCC.
Selective Hepatic Vascular Exclusion versus Pringle Maneuver in Major Liver Resections: Prospective Study
Authors: Smyrniotis Vassilios E. , Kostopanagiotou Georgia G. , Contis John C. , Farantos Charalampos I. , Voros Dionisios C. , Kannas Dimitrios C. , Koskinas John S. 
Published: November 2003

AbstractSelective hepatic vascular exclusion (SHVE) and the Pringle maneuver are two methods used to control bleeding during hepatectomy. They are compared in a prospective randomized study, where 110 patients undergoing major liver resection were randomly allocated to the SHVE group or the Pringle group. Data regarding the intraoperative and postoperative courses of the patients are analyzed. Intraoperative blood loss and transfusion requirements were significantly decreased in the SHVE group, and postoperative liver function was better in that group. Although there was no difference between the two groups regarding the postoperative complications rate, patients offered the Pringle maneuver had a significantly longer hospital stay. The application of SHVE did not prolong the warm ischemia time or the total operating time. It is evident from the present study that SHVE performed by experienced surgeons is as safe as the Pringle maneuver and is well tolerated by the patients. It is much more effective than the Pringle maneuver for controlling intraoperative bleeding, and it is associated with better postoperative liver function and shorter hospital stay.
Barrett’s Esophagus: Environmental Influences in the Progression of Dysplasia
Authors: Boulton Ralph A. , Usselmann Bernhard , Mohammed Imtiyaz , Jankowski Janusz 
Published: November 2003

AbstractBarrett’s esophagus (BE) is composed of multiple lineages including Paneth cells and endocrine cells in addition to gastric and intestinal cells. Although the origin of the BE stem cell is a matter of conjecture, the stem cells are clearly multipotent, and therefore the phenotype is restricted by genomic imprinting (termed restricted potency). Recent evidence suggests that the microenvironment may select various lineages. In this regard the proportion of gastric and specialized intestinal metaplastic cells has been attributed to the composition of the refluxate, acid or bile, respectively. Experimental evidence also implicates specific xenobiotics in this process, including bile acids. In particular we discuss the potential biologic roles of bile acids in epithelial adaptation from in vivo and in vitro models.