bluuebunny/crossref_metadata_2025 huggingface dataset:
Existências mínimas em educação: algumas considerações sobre construção e escala
Authors: Silva Luiz Carlos Quirino da , Adó Máximo Daniel Lamela
Published: November 2022

Partimos da ideia de que o pensamento diferencial, em educação, é caracterizado por um maquinismo que compreende duas dimensões principais: a da construção (ou produção) e da escala (ou perspectiva). Dentre todas as formas de construção, privilegiamos a que é engendrada pelo que chamamos – reverberando algumas proposições de Deleuze e Guattari – de máquina literária ou ficcional e que opera através de uma perspectiva de leitura, produzindo um discurso que não poderia ser considerado nem verdadeiro nem falso, pois é destinado àquilo que ainda não existe ou que existe somente em potência. Argumentamos, ainda, que a realidade é produto de uma espécie de intertextualidade conformadora das existências, ou pelo menos no que diz respeito a seu sentido e valor. Na articulação de tais mecanismos são maquinadas as existências. Contudo algumas delas, apesar de existirem, possuem uma realidade bastante precária. Por isso, acompanhando as leituras de Étienne Souriau feitas por David Lapoujade, afirmamos que povoar o mundo – e consequentemente a educação – de ficções (que são uma radicalização dos seres identificados como virtuais pelos autores) consiste em um procedimento inseparável da defesa dessas existências frágeis.
Change Toward Healthier Lifestyles Is Associated With Better Health-Related Quality of Life in Long-Term Colorectal Cancer Survivors
Authors: Eyl-Armbruster Ruth Elisa , Thong Melissa S.Y. , Carr Prudence R. , Jansen Lina , Chang-Claude Jenny , Hoffmeister Michael , Brenner Hermann , Arndt Volker
Published: November 2022

Background: Little is known about how changes in a constellation of lifestyle factors affect health-related quality of life (HRQoL) in colorectal cancer (CRC) survivors. Our study aimed to investigate the association between changes in healthy lifestyle and HRQoL over time in survivors of stage I–IV CRC. Methods: We included 2,283 long-term (≥5 years postdiagnosis) survivors. A healthy lifestyle score (HLS) comprising smoking, alcohol consumption, diet, physical activity, and body fatness was derived at diagnosis and 5-year follow-up (5YFU) and categorized as low, moderate, or high. We assessed HRQoL with the EORTC Quality of Life Questionnaire-Core 30 at 5YFU and 10-year follow-up. We used multivariable linear regression and linear mixed models to explore associations between changes in HLS and HRQoL over follow-up. Results: A low baseline HLS was associated with poorer functioning and global health/QoL and a higher symptom burden at 5YFU compared with a high baseline HLS. An improved HLS from baseline to 5YFU was associated with better functioning, higher global health/QoL, and fewer symptoms at 5YFU than a maintained-high HLS. In longitudinal analyses, improved HLS was associated with better functioning at follow-up. Survivors with a maintained-high or an improved HLS reported generally less fatigue, pain, and dyspnea at follow-ups compared with survivors with a maintained-low or decreased HLS. Conclusions: Change toward a healthier lifestyle since diagnosis was associated with better HRQoL in long-term CRC survivors. Our results support the importance of maintaining and/or promoting a healthier lifestyle among CRC survivors postdiagnosis.
T cell receptor convergence is an indicator of antigen-specific T cell response in cancer immunotherapies
Authors: Pan Mingyao , Li Bo
Published: November 2022

T cells are potent at eliminating pathogens and playing a crucial role in the adaptive immune response. T cell receptor (TCR) convergence describes T cells that share identical TCRs with the same amino acid sequences but have different DNA sequences due to codon degeneracy. We conducted a systematic investigation of TCR convergence using single-cell immune profiling and bulk TCRβ-sequence (TCR-seq) data obtained from both mouse and human samples and uncovered a strong link between antigen-specificity and convergence. This association was stronger than T cell expansion, a putative indicator of antigen-specific T cells. By using flow-sorted tetramer+single T cell data, we discovered that convergent T cells were enriched for a neoantigen-specific CD8+effector phenotype in the tumor microenvironment. Moreover, TCR convergence demonstrated better prediction accuracy for immunotherapy response than the existing TCR repertoire indexes. In conclusion, convergent T cells are likely to be antigen-specific and might be a novel prognostic biomarker for anti-cancer immunotherapy.
How vertebrates got their bite
Authors: Schilling Thomas F , Le Pabic Pierre
Published: November 2022

A newly discovered enhancer region may have allowed vertebrates to evolve the ability to open and close their jaws.
The fight for evolution
Authors: Altınışık N Ezgi
Published: November 2022

As the Turkish government intensified its attacks on the theory of evolution, the academic community rallied to push back. A researcher recounts how she decided to join them.
A Survey of Cyber Crime Awareness Among Netizens of Higher Education Institutions: A Case Study of Zetech University
Authors: Wambui Boniface Mwangi , Nyambura Hellen , Njeru Daniel
Published: November 2022

Protecting the integrity and confidentiality of information in sophisticated network systems is becoming increasingly vital and difficult. The computer may have been used in order to commit the crime and in other cases the computer may have been the target of the crime. The purpose of this research was to determine the level of awareness of cyber-attacks among students and staff of higher education institutions and to propose mechanisms to overcome cybercrimes attacks. A mixed technique approach was utilized in the study. The study was conducted at Zetech University with a purposively randomly selected population of 260 staff and students, and a sample of 150 was obtained. The descriptive statistics was used in the quantitative design to show the distribution of scores using a few indices. According to the findings, 63.4 percent of the participants had no cyber security awareness training, whereas 36.6 percent had. It is impossible to exaggerate the value of workplace cyber security awareness. The majority of participants (91.1%) were aware of the many sorts of cybercrimes, whereas 8% were unsure. 58.9% of respondents strongly concurred that they had never trusted websites that asked for their bank card information. Focusing on cyber security awareness reduces cybercrimes by more than 50%, according to 65.2 percent of participants. 72.3 percent firmly agreed that using encryption techniques to safeguard sensitive information was a good idea. The study's findings demonstrate that a rise in cybercrime is causing physical harm to individuals, with the majority of respondents saying that hackers had stolen their data and harmed them. Based on our research, we advise higher education institutions to invest in cutting-edge research facilities, place more emphasis on internal and external cyber security research and development, and emphasize that top management allocates sufficient financial resources to IT infrastructure and cyber security awareness trainings. Higher education institutions should regularly host conferences and training sessions for all staff and students on cyber security. The team in charge of overseeing the networks and IT infrastructure must make sure that email filtering and intrusion detection systems have been put in place to detect harmful assaults on university networks and systems.
Research on the Basic Theory of Contemporary Pedagogy: From Background to Recent Advances
Authors: Zhenzhou WANG , Yang ZHANG
Published: November 2022

Research on the basic theory of contemporary pedagogy from background to recent advances is conducted in this paper. The cultural nature of pedagogy means the existence of cultural hegemony in pedagogy, and cultural colonization directly affects the way of speaking and academic trajectory of comparative education scholars. Pedagogical knowledge, as one of the human knowledge categories, has been accompanied by the development of human society, the improvement of cognitive ability and the three major transformations of human knowledge type. The three major transformations of human knowledge have presented different knowledge beliefs, structures and contents, and thus different knowledge forms and paradigms in various historical periods. and paradigms. Hence, this paper gives the novel suggestions regarding the related studies.
Exploring the Ways of Constructing Organizational Cultural Atmosphere in Colleges and Universities
Authors: Jin Wei , Bojing Chen
Published: November 2022

Exploring the ways of constructing organizational cultural atmosphere in colleges and universities is the main focus of this study. A university is a social organization whose mission is to inherit and innovate human civilization. Everything that happens in this organizational system is influenced by its culture, and ideological and political education is no exception. Management theory argues that the success or failure of organizational behavior is often attributed to organizational culture. Organizational culture is a general term for group consciousness such as values, ways of thinking, work styles, and codes of conduct that are commonly accepted by members of the organization. By cultivating and shaping this culture, the organization influences the working attitude of members and guides the achievement of the organization's goals. Hence, this paper gives the novel ideas of nehancing the organizational cultural atmosphere in colleges and universities. The proposed ideas will be tested in the future study.
Research on the Application of Information Technology in Physical Education Teaching in Colleges and Universities
Authors: Xianpeng Dai
Published: November 2022

Research on the application of information technology in physical education teaching in colleges and universities is studied in the paper. In physical education in colleges and universities, teachers and students should clearly understand that building an excellent sports culture under the needs of the modern era and society is the organic integration of physical training and moral education in a subtle way. With the advent of the Internet, it has provided a wealth of rich information, which enriches people's brains and enlivens students' minds, modern information technology provides information resources that are far beyond the reach of the teacher. Hence, this paper discusses the novel conbinations of the different models into the idea and propose the novel comprehensive information technology in physical education teaching in colleges.
Exploring the Innovation of the Theory of All-Round Development of People to the Teaching Methods of Ideological and Political Education
Authors: Yuxia Han
Published: November 2022

Exploring the innovation of the theory of all-round development of people to the teaching methods of ideological and political education is studied in the paper. The all-round development theory of Marx and Engels has gone through a arduous and long process. As the ultimate goal of human development, the theory of all-round development of man is contained in Marx's theory of humanism. To understand college students' sense of the acquisition in ideological and political education from multiple dimensions, it is necessary to understand the subjective and objective unity of knowledge experience from a basic dimension, and to then understand the impact of meaning and development on sense of acquisition from a deep dimension. Hence, this paper proposes the novel combinational model to suggest the further educational activities.
Fierce Hope: Youth Activism in Aotearoa
Authors: Nairn Karen , Siglo Judith , Showden Carisa R. , Matthews Kyle R. , Kidman Joanna
Published: November 2022

Youth activism has been a defining feature of Aotearoa's recent political landscape. Amidst these unsettling political times haunted by climate change, colonisation, ongoing inequality and the upheaval of the pandemic, the political actions of young New Zealanders are a source of inspiration, challenge and renewal. Fierce Hope opens the doors on six influential activist groups: ActionStation, Generation Zero (Auckland), InsideOUT, JustSpeak, Protect Ihumātao, and Thursdays in Black (Auckland). Participants from these groups, through interviews, explain vividly what future they want for our country and how we can get there. They address an array of urgent issues, from indigenous rights to the justice system and imprisonment; from climate change to gender and sexual inequalities. In their voices we hear hope, anger, despair and anxiety – emotions which inform and galvanise activism. A connecting thread is how people within these different groups collectively negotiate their visions and strategies to achieve change. Their stories provide important insights into the immense demands of activism, and help inform radical new ways of living and being together in Aotearoa New Zealand.
Clinical Profile of Refractive Errors Associated with Screen Time in Children Aged 5-15 Years in a Tertiary Care Hospital of Southern India during COVID Pandemic: A Prospective Study
Authors: Servey Navneeth , Bharathi NVN Prasanna , Radhika M , Hyndavi B , Srividya B
Published: November 2022

Introduction: Refractive errors cannot be prevented, but it is important to detect them early to improve the quality of life and prevention of blindness. Refractive errors screening in children during COVID pandemic was difficult task as they were high-risk group. Increased near activity due to online classes and smart devices usage may increase the uncorrected refractive errors. The study emphasizes on the refractive errors screening during COVID pandemic. Aim: To study the clinical profile of refractive errors of the children aged 5-15 years in a tertiary care hospital in COVID pandemic in association with screen time, outdoor activity, type of gadget, amblyopia and educational status of mother. Materials and methods:This was a hospital based prospective analytical study conducted in children 5-15 yrs attending the Ophthalmology Outpatient Department of ESIC Medical College and Hospital from May 2021 to October 2021.Children were screened for refractive errors and compared with the refractive errors data of different children of same age referred from Paediatric Outpatient Department and who attended to Ophthalmology Outpatient Department for regular eye checkup in pre-pandemic time. Unaided visual acuity of all children were measured with the help of Snellen’s chart. Children with refractive errors underwent Cycloplegic Retinoscopy followed by post-mydriatic test. Screen time and outdoor activity duration were recorded. Interpretation and analysis of obtained results was carried out using Statistical Package for Social Sciences version 22.0 for descriptive statistics. Non-parametric tests like Pearson Chi-square test were used to express the qualitative data.Data with p-value less than 0.05 was considered statistically significant. Results: A total of 790 children were screened out of which 358 (45.3%) presented with refractive error when compared with the pre pandemic prevalence 276 (34.9%) out of 790 children screened, presented with the refractive error. A total of 118 (33%) of the children presented with increased blink rate associated with increased screen time and dry eye. Rate of progression of more than 1D was observed in 44 (12.29%) of which Myopia 28 (7.8%) Astigmatism 10 (2.7%) and hypermetropia 6 (1.6%) in 6 months. A total of 286 (79.8%) children presented with myopia and 24 (6.7%) presented with hypermetropia, 48 (13.4%) presented with astigmatism. A total of 258 (72.06%) presented with screen time for 4-7 hrs, and 32 (8.9%) children presented with amblyopia. Conclusion: Refractive errors increased due to smart classes in schools or use of laptops, television viewing, computers or mobiles. Hence, this reinforces the need to screen all the school going children and children with the history of gadgets use
COVID-19 Vaccination: An Observational Study on Postvaccination Infections and Side-effects
Authors: Sanjana Perumalla Hima , Kumari Somisetty Lakshmi , Devi K Maruthi , Bhaskar K , Himaja Y
Published: November 2022

Introduction: Given the mortality and morbidity caused by the Coronavirus Disease 2019 (COVID-19) and the lack of therapeutic options, the need for vaccines has become inevitable. Knowledge about covid infection after vaccination and vaccine-related side-effects are essential to educate people and avoid myths about vaccination. Aim: To evaluate the side-effects and incidence of COVID-19 in vaccinated people, and to compare the side-effect profile and postvaccination incidence of the infection. Materials and Methods: This cross-sectional, email-based, survey was done from 1st July 2021 to 31st July 2021 at Guntur Medical College, Guntur, Andhra Pradesh, India. A total of 920 people were sent emails about the details and questionnaire of the study. All COVID-19 vaccinated and those who were more than 18 years of age were included in this study. A total of 506 subjects responded. Total 18 questions in the English language were there. The questions were about demographics, co-morbidities, the name of vaccine taken, postvaccination adverse effects, and COVID-19 positivity. Results: Of the 506 vaccinated subjects, 287 (56.71%) received Covaxin®, 203 (40.11%) received Covishield® and 16 (3.16%) received other vaccines (BioNTech COVID-19 Vaccine-8, Sputnik V-3, Spikevax-5). The mean age of the participants was 37 years, and 45.2% (229) were females and 54.8% (277) were males. Side-effects were reported by 73.1%, and 65.17% of individuals after the first and second doses of Covaxin®, respectively, compared to 84.7% and 62.5% after Covishield®. Local pain and tiredness were the most common symptoms after Covaxin® and Covishield®. Conclusion: Local pain and tiredness were the most common side-effects of Covaxin® and Covishield® vaccines. The number of participants in other vaccine groups was very minimal to study and compare their effects. Overall, the vaccines are safe and seem to show protection, although mild side-effects can be observed, which are usually non fatal. No difference in the incidence of infections was observed between vaccine groups.
Neck Dermoid Cyst with Rare Imaging Appearance on Ultrasound, Elastography, and Computed Tomography
Authors: Nagendra Vadlamudi , Phatak Suresh Vasant , Patwa Prerna Anup , Pattabiraman Suhasini , Prashanti Ghanta
Published: November 2022

Dermoid cyst is a type of inclusion cyst and a benign cystic teratoma containing two or more germ cell layers. It can show variable appearance on ultrasound and Computed Tomography (CT) as it is derived from squamous cell epithelium (ectoderm) and contains dermal-derived elements such as skin appendages, hair follicles, sebaceous and sweat glands. It is uncommon for a dermoid cyst to occur in the neck region during old age. The present case report highlights a rare imaging appearance of a dermoid cyst, presenting in a 65-year-old elderly male as a midline neck swelling, displaying a rare “coin in sack” appearance on ultrasound, “sack of marbles sign” on Contrast-Enhanced CT (CECT). On strain elastography, it showed characteristics of a hard mass. Diagnosing this type of large dermoid cyst with its radiological appearance is challenging. Multimodality imaging is often needed for early intervention, to prevent its rupture and transformation into malignancy. The dermoid cyst was surgically excised, and the patient was symptomatically normal on follow-up.
A Study of Plasma Homocysteine Level in Children with Autism
Authors: Al-Beltagy Shahenda Bdair , El-Serogy Hesham Ahmed , Elaziz Sahar Abd ElAzim Abd , Al-Gohary Tarek Mohammed
Published: November 2022

Background: Autism is a neurodevelopmental disorder that appears in early life. B6 and B12, and folate support homocysteine (Hcy) metabolism. Hence, any defect to them leads to Hcy accumulation in the body. Hcy, vitamins B12, B6 and folate are important in psychiatric disorders such dementia, schizophrenia, and autism. This study intended to compare the plasma Hcy levels in normal and autistic cases to find out whether there is difference between the levels of Hcy in plasma of autistic and normal children.

Methods: This case control study enrolled 60 children who were allocated in two groups 30 with autism and other 30 as controls. All patients were exposed to full history taking, physical examination, mental status examination, hearing test, routine lab investigations and specific lab investigations (serum folic acid, plasma vitamin B12 and Hcy level).

Results: Childhood Autism Rating Scale (CARS) level among autistic children was 49.400 ± 5.840. The mean plasma Hcy level was considerably higher in children with autism than controls (P value< 0. 01). The mean serum folic acid level and vit B12 level was significantly reduced in autistic cases than controls (P value< 0. 01). There was a statistically significant positive correlation between plasma Hcy level (µmol/L) and CARS level in children with autism (P value< 0. 01).

Conclusions:  Children with autism have increased levels of Hcy, and decreased levels of folic acid and vit B12. So, Hcy may be used as a clinical biomarker for early diagnosis and managing of autistic children.
Alat Resusitasi Jantung Paru
Authors: Noventra Lang Jiwa , Lim Resmana
Published: November 2022

Alat Resusitasi Jantung Paru (RJP) yang sudah tersedia di pasaran memiliki harga yang sangat mahal, hanya dimiliki dan di operasikan oleh tenaga ahli medis. Selain itu kesadaran masyarakat akan pentingnya Bantuan Hidup Dasar sangatlah rendah. Dalam TA ini akan dibuat alat resusitasi jantung paru (RJP). Dalam pembuatan alat resusitasi jantung paru menggunakan 2 buah motor stepper sebagai penggerak utama dan juga menggunakan Arduino uno sebagai controller. Perbedaan dengan alat-alat yang telah di buat sebelumnya sebagian besar menggunakan piston sebagai penggeraknya. Dengan adanya alat resusitasi jantung paru yang mudah di operasikan, diharapkan masyarakat dapat melakukan pertolongan pertama terhadap kasus henti jantung dan mengurangi angka kematian yang diakibatkan henti jantung. Hasil dari pembuatan alat ini adalah sebagai purwarupa alat resusitasi jantung paru (RJP) yang mudah di operasikan oleh masyarakat.
Hesitação à Vacina de COVID-19 para Crianças no Brasil
Authors: M. Campos Luis Antonio , Santana Claudio Manoel Luiz , M. Silva Cristiane , X. Moraes Felipe , Domingos Luiz Fabio , B. A. Pereira Diogo , O. Silva Kelly Dayanne , S.  Hernandes Raphaella , F. Paiva Scheila , T. Silva José Carlos , T. Hirschle Ana Lucia , Resende Gisele Cristina , S; Torres Marck
Published: November 2022

Currently, one of the most effective strategies in the fi ght against COVID-19 is vaccination. With an expressive number of vaccinated in Brazil, specialists and Brazilian Health Regulatory Agency (ANVISA) present as a national vaccination plan the use of immunizations for children, which has caused a certain strangeness and hesitation on the part of those responsible and has divided opinions among the population as a whole. It is known that many opinions are the result of political and ideological positions and that they are in favor or against vaccination. Some groups present arguments that defend the immediate vaccination of children and another that maintains possible damages to health that can lead to psychological and physical consequences, in addition to deeming unnecessary. This work seeks to answer the following question: does the perception of risk and benefi t of vaccination against COVID-19 affect the attitude of parents or guardians to vaccinate their children? Thus, the main objective is to analyze the vaccination of children through the perception of risks or benefi ts and whether factors such as gender, education and sharing residence with children affect the decision to hesitate before vaccinating. The research had 293 participants, of both sexes (M=36.5% and F=63.5%), with an average age of 38 years, distributed in 17 Brazilian states. After statistical analysis, it was found that gender is not a signifi cant variable for the decision to vaccinate children, as well as schooling and he fact of living with the child. However, a signifi cant correlation was found between the perception of benefi t (p=.016) and risk (p=.001) and the decision to vaccinate, with the perception of risk being more determinant in the attitude of hesitation .Keyword: pandemic, vaccine, children, immunization, hesitation.
A educação musical das crianças no Brasil: leis e outros documentos normativos
Authors: Fernandes José Nunes
Published: November 2022

Este ensaio visa descrever como se constitui a educação das crianças brasileiras no que se refere à educação geral (percurso histórico até o século XXI) e os aspectos relativos à educação musical, nesse mesmo período. A descrição se delimita à pré-escola (3 a 5 anos), não sendo, portanto, incluída a creche. As fontes usadas foram leis sobre educação e outros documentos normativos, gerais e específicos, dos níveis estabelecidos acima, bem como artigos e livros que discutem a educação das crianças brasileiras.
Mitochondrial import of the long and short isoforms of human uncoupling protein 3
Authors: Renold Anja , Koehler Carla M. , Murphy Michael P.
Published: July 2002

Human uncoupling protein 3 (UCP3) has two RNA transcripts that arise from the differential processing of the same gene product. One encodes the full length protein (UCP3L) while the other encodes a truncated version (UCP3S) lacking the sixth membrane spanning domain. The roles of the two isoforms are not known, but a mutation that decreases the proportion of UCP3L decreases fat oxidation and increases susceptibility to obesity. In the ADP/ATP carrier, a protein closely related to UCP3, the sixth membrane spanning domain is required for insertion into the inner membrane. Therefore, defective membrane insertion of UCP3S may account for the different effects of the two isoforms in vivo. We investigated mitochondrial import of the two UCP3 isoforms. When epitope‐tagged versions of UCP3S and UCP3L were expressed in COS7 cells, both were inserted into the mitochondrial inner membrane. Translation in vitro followed by incubation with isolated mitochondria showed that both isoforms were inserted into the inner membrane, however, the insertion of UCP3S was significantly slower.
Postnatal maternal deprivation aggravates experimental autoimmune encephalomyelitis in adult Lewis rats: reversal by chronic imipramine treatment
Authors: Stephan Michael , Straub Rainer H. , Breivik Torbjørn , Pabst Reinhard , von Hörsten Stephan
Published: July 2002

Stressful experiences can modulate multiple sclerosis, but stress protection is currently not considered a treatment option. Here, we show that maternal deprivation, an adverse stress experience in infancy, increases emotionality in behavioral tests of adult female Lewis rats and concomitantly causes a more severe course of experimental autoimmune encephalomyelitis. Treatment of these effects in adulthood by chronic antidepressants (imipramine) reversed the behavioral symptoms and attenuated the course of the encephalomyelitis in deprived rats. Increased IL‐4 plasma levels accompanied the protective‐like effects of antidepressants. In contrast, attempts to prevent these effects in infancy by tactile stimulation aggravated the encephalomyelitis, possibly by decreasing corticosterone and increasing IFN‐γ levels during the disease. This indicates that antidepressants exert protective effects in an animal model of multiple sclerosis, and suggests that drugs modifying stress responsiveness may have a potential role as adjuvant treatment of the disease.
Light‐Directed Simultaneous Synthesis of Oligopeptides on Microarray Substrate Using a Photogenerated Acid
Authors: Komolpis Kittinan , Srivannavit Onnop , Gulari Erdogan
Published: July 2002

Photogenerated acid (PGA) was used as the acid to remove the protection group from amino acids or peptide oligomers. Comparative study of the deprotection using a PGA, trisarylsulfonium antimonyhexafluoride (SSb), and trifluoroacetic acid (TFA) was performed on glass microscope slides. The results showed that PGA can replace TFA in the deprotection step of oligopeptide synthesis with comparable efficiencies. Acids needed for the deprotection step were generated in situ by light activiation of the precursor molecule on the microwell substrate. A maskless laser light illumination system was used to activate the precursor. The accuracy of the amino acid sequence of the synthesized oligopeptide and the location of the synthesis was illustrated by the specific recognition binding of two different models: lead(II) ion‐peptide biosensor for lead(II) and human protein p53 (residue 20–25)‐mouse MAb DO1. After parallel synthesis of the target peptide models and their analogues based on the predetermined pattern, specific binding treatment, and fluorescence labeling, the fluorescence emission images of the oligopeptide microarray showed fluorescence intensity as a result of specific binding at the correct locations of the array. The stepwise synthesis efficiencies of pentapeptide synthesis on the microwell substrate range are ∼96–100% and do not decrease with respect to the chain length of the peptide.
Correlation of Fermentation Yield with Yeast Extract Composition as Characterized by Near‐Infrared Spectroscopy
Authors: Kasprow Robert P. , Lange Andrew J. , Kirwan Donald J.
Published: July 2002

Complex, ill‐defined mixtures of natural origin are often used as nutrients in the production of biological products through microbial fermentation. Product yields are affected by variation in these natural products. It was desired to examine near‐infrared spectroscopy as a rapid screening tool for qualifying raw material lots. Specifically, the characterization of yeast extract was investigated. The model system consisted of a Merck & Co., Inc., microbial fermentation process. Cell mass and specific product yields are dependent upon variations in the yeast extract used in the medium. Partial least‐squares regression on the second‐derivative spectral absorbances of various yeast extracts in the ranges 1150–1380, 1554–1826, and 2100–2300 nm resulted in the development of models with multiple correlation coefficients of 0.99 for cell mass yields and 0.96 for specific product yields in large‐scale fermentations. These models could also be used to predict cell mass yields in 15 L batch fermentations and specific product yields in 2‐L shake flasks.
Context‐dependent conformation of diethylglycine residues in peptides
Authors: Kaul R. , Balaram P. , Banumathi S. , Velmurugan D. , Ravikumar K. , Balaji Rao R.
Published: July 2002

Abstract: Diethylglycine (Deg) residues incorporated into peptides can stabilize fully extended (C5) or helical conformations. The conformations of three tetrapeptides Boc‐Xxx‐Deg‐Xxx‐Deg‐OMe (Xxx = Gly, GD4; Leu, LD4 and Pro, PD4) have been investigated by NMR. In the Gly and Leu peptides, NOE data suggest that the local conformations at the Deg residues are fully extended. Low temperature coefficients for the Deg(2) and Deg(4) NH groups are consistent with their inaccessibility to solvent, in a C5 conformation. NMR evidence supports a folded β‐turn conformation involving Deg(2)‐Gly(3), stabilized by a 4 → 1 intramolecular hydrogen bond between Pro(1) CO and Deg(4) NH in the proline containing peptide (PD4). The crystal structure of GD4 reveals a hydrated multiple turn conformation with Gly(1)–Deg(2) adopting a distorted type II/II′ conformation, while the Deg(2)–Pro(3) segment adopts a type III/III′ structure. A lone water molecule is inserted into the potential 4 → 1 hydrogen bond of the Gly(1)–Deg(2) β‐turn.
Bioactive fMLF‐OMe analogs containing a N‐terminal oximic or formylhydrazonic moiety
Authors: Torrini I. , Paglialunga Paradisi M. , Pagani Zecchini G. , Lucente G. , Mastropietro G. , Spisani S.
Published: July 2002

Abstract: In order to obtain chemotactic peptides with selective bioactivity, a new type of structural modification was introduced at the N‐terminal position of HCO‐Nle‐Leu‐Phe‐OMe. Two groups of analogs have been synthesized both containing a N‐terminal residue of the X=C(R)‐CO‐type replacing the native HCO‐NH‐CH(R)‐CO‐. In particular, the A group of pseudopeptides (2a‐d) possesses a N‐terminal oximic fragment (X=HO‐N) and the B group (3a‐d) a formylhydrazone fragment (X=HCO‐NH‐N). These new ligands have been examined for their capacity to induce chemotaxis and other cellular responses such as superoxide anion production and lysozyme release; although significantly active as chemoattractants they have been found to be practically devoid of secretagog activity, thus exhibiting selective behavior. The adopted chemical modification seems extensible in designing a new class of pseudopeptides (hydrazonopeptides) structurally related to both hydrazinopeptides and peptides containing α,β‐unsaturated residues.
Maurotoxin and the Kv1.1 channel: voltage‐dependent binding upon enantiomerization of the scorpion toxin disulfide bridge Cys31–Cys34
Authors: Lecomte C. , Ben Khalifa R. , Martin‐eauclaire M.‐F. , Kharrat R. , El Ayeb M. , Darbon H. , Rochat H. , Crest M. , Sabatier J.‐M.
Published: July 2002

Abstract: Maurotoxin (MTX) is a 34‐amino acid polypeptide cross‐linked by four disulfide bridges that has been isolated from the venom of the scorpion Scorpio maurus palmatus and characterized. Maurotoxin competed with radiolabeled apamin and kaliotoxin for binding to rat brain synaptosomes and blocked K+ currents from Kv1 channel subtypes expressed in Xenopus oocytes. Structural characterization of the synthetic toxin identified half‐cystine pairings at Cys3–Cys24, Cys9–Cys29, Cys13–Cys19 and Cys31–Cys34. This disulfide bridge pattern is unique among known scorpion toxins, particularly the existence of a C‐terminal ‘14‐membered disulfide ring’ (i.e. cyclic domain 31–34), We therefore studied structure–activity relationships by investigating the structure and pharmacological properties of synthetic MTX peptides either modified at the C‐terminus {i.e. MTX (1–29), [Abu31,34]‐MTX and [Cys31,34, Tyr32]d‐MTX} or mimicking the cyclic C–terminal domain [i.e. MTX (31–34)]. Unexpectedly, the absence of a disulfide bridge Cys31–Cys34 in [Abu 31,34]‐MTX and MTX (1–29) resulted in MTX‐unrelated half‐cystine pairings of the three remaining disulfide bridges for the two analogs, which is likely to be responsible for their inactivity against Kv1 channel subtypes. Cyclic MTX (31–34) was also biologically inactive. [Cys31,34, Tyr32]d‐MTX, which had a ‘native’, MTX‐related, disulfide bridge organization, but a d‐residue‐induced reorientation of the C–terminal disulfide bridge, was potent at blocking the Kv1.1 channel. This peptide‐induced Kv1.1 blockage was voltage‐dependent (a property not observed for MTX), maximal in the low depolarization range and associated with on‐rate changes in ligand binding. Thus, the cyclic C–terminal domain of MTX seems to be crucial for recognition of Kv1.3, and to a lesser extent, Kv1.2 channels and it may contribute to the stabilization and strength of the interaction between the toxin and the Kv1.1 channel.
Isolation of leptin‐binding peptides from a random peptide phage library
Authors: Chan K.‐W. , Li E.T.S. , Lim B.‐L. , Lim P.‐L. , Tam F.C.H.
Published: July 2002

Abstract: Leptin plays a role in regulating the body weight in mice. Injection of recombinant mouse leptin expressed in Escherichia coli reduced the food intake and body weight in normal, ob/ob and diet‐induced obesity mice. Hyperglycemia, hyperinsulinemia and hypothermia can also be corrected inob/ob mice after leptin injection. Leptin is a 16‐kDa secretory protein comprising 167 amino acids produced in adipose tissue and is secreted to blood stream. In this study, a recombinant mouse leptin was generated and purified from a baculovirus expression system. This protein was used to identify putative ligands using a phage library of random peptides. Three leptin‐binding phage clones were found, which were characterized by DNA sequencing and ELISA methods. The amino acid sequences of the reactive peptides are: LAYCSDPVRCLVWWY, MFWISAVSFVDHALV and LVLVLSAFLCCGVG. All three clones bound to recombinant human and mouse leptins. These peptides may be useful tools to study leptin–receptor interaction, food intake and body weight regulation.
Studies on the conformational properties of CP‐1042−55, the hinge region of CP‐10, using circular dichroism and RP‐HPLC
Authors: Lazoura E. , Aguilar M.‐I. , McLeish M.J.
Published: July 2002

Abstract: The conformational properties of CP‐1042−55, a peptide corresponding to the hinge region of CP‐10, were investigated using circular dichroism spectroscopy and reverse‐phase high‐performance liquid chromatography (RP‐HPLC). The circular dichroism studies indicated that CP‐1042−55 formed considerable secondary structure in the presence of hydrophobic solution environments including 50% acetonitrile, 50% trifluoroethanol and 200 mm sodium dodecyl sulfate, which comprised a mixture of α‐helix and β‐sheet. The effect of temperature on the conformation of CP‐1042−55 was investigated between 5 and 40°C, with very small changes in the spectra being observed.RP‐HPLC was then used to investigate the effect of temperature on the conformation of CP‐1042−55 in the presence of a hydrophobic surface. Using a C18‐adsorbent, CP‐1042−55 exhibited a conformational transition at 25°C, which was associated with an increase in the chromatographic contact area and the binding affinity of the peptide for the stationary phase. In addition, near‐planar bandbroadening behaviour indicated that conformational species interconverted with rapid rate constants compared with the chromatographic time scale. These results indicated that the conformational change at 25°C in theRP‐HPLC system most likely corresponds to the unfolding of an α‐helical and/or β‐sheet structure to an extended coil structure. Therefore, the strong chemotactic properties of this peptide may be attributed to its ability to form considerable secondary structure in the presence of a hydrophobic environment.
Conformational characterization of a helix‐nucleated bicyclic GCN4 decapeptide by proton NMR
Authors: Zhang M. , Wu B. , Baum J. , Taylor J.W.
Published: July 2002

Abstract: A bicyclic decapeptide, GCN4brM1, which was designed to be a helix‐locked analog of the DNA‐binding basic region from the yeast transcription factor GCN4, was synthesized and characterized using circular dichroism (CD) spectropolarimetry and 1H‐NMR. This peptide has two Lysi, Aspi+4 side chain lactam bridges incorporated into its structure in overlapping positions in the peptide chain, linking residues 3 and 7 and residues 4 and 8. CD spectra of GCN4brM1 in aqueous solution are consistent with the expected helical conformation, and indicate that this conformation is remarkably resistant to heat denaturation and is essentially unchanged by addition of 50% (v/v) trifluoroethanol (TFE) as cosolvent. NMR spectra measured in aqueous solution at −5°C show long‐range nuclear Overhauser effects (NOEs) that are consistent with anα‐helical conformation throughout the peptide structure. The measured 3JHN coupling constants are also in agreement with an α‐helical structure. Extremely slow proton–deuterium exchange rates measured for backbone amides in the middle of the peptide indicate that this helix is highly stabilized and rarely unfolds within the side chain bridged sequence. NOE‐constrained molecular dynamics simulations gave rise to a single family of converged structures that are fully α‐helical throughout the GCN4brM1 backbone, and show a single, well‐defined conformation for the two side chain bridges. This study demonstrates that two overlapping Lysi, Aspi+4 lactam bridges, positioned in consecutive residue positions in a hexapeptide segment, form a rigid α‐helical structure in aqueous solution that is propagated in both the N‐terminal and C‐terminal directions.
Sequencing and model structure of a Naja naja atra protein fragment
Authors: Prabhakaran M. , Dudek . M. , Raghunathan G.
Published: July 2002

Abstract: We report the amino acid sequence of a basic protein isolated from the snake venom of Naja naja atra. An automated Edman sequencer was used to determine the 65‐residue sequence, aided by electrospray ionization/mass spectrometry. Online reduction and pyridylethylation of the peptide was performed to identify the cysteine residues. Trypsin, chymotrypsin and aspartic digestions were carried out to derive peptide fragments for further sequencing. Fragmented peptides were overlapped to obtain the complete sequence. Molecular mass measurements of the whole protein and its fragments were used as a countercheck for sequence assignment. Further confirmation of the sequence was indicated by sequence homology to other snake venom neurotoxins. A molecular model of the tertiary structure was constructed based on sequence homology, and was refined by global minimization and extensive quality control algorithms. Electrostatic and hydrophobic surface calculations and molecular dynamics simulations were carried out to determine the functional properties of the molecule.
Syntheses of four peptides from the immunodominant region of hepatitis C viral pathogens using PS‐TTEGDA support for the investigation of HCV infection in human blood
Authors: Kumar K.S. , Das M.R. , Rajasekharan Pillai V.N.
Published: July 2002

Abstract: Four peptides were designed and synthesized on a highly solvating copolymer of tetraethyleneglycol diacrylate cross‐linked polystyrene (PS‐TTEGDA) support with very high purity and yield. The polymer was synthesized in various cross‐linking densities (1, 2, 3, 4, 5 and 10%) using radical aqueous suspension polymerization. Four per cent PS‐TTEGDA resin showed rigidity and mechanical characteristics comparable with those of divinylbenzene cross‐linked polystyrene (PS‐DVB) support. Swelling and solvation characteristics of PS‐TTEGDA were much higher than PS‐DVB support in all solvents used in solid‐phase peptide synthesis. Forty‐eight hour treatment of the support with neat trifluoroacetic acid did not show any change in its infrared spectra. PS‐TTEGDA could be functionalized with chloromethyl, aminomethyl and hydroxymethyl functional groups under various controlled conditions. Synthetic utility of the support was demonstrated by the synthesis of four peptides selected from the envelope and nonstructural protein region of the prototype hepatitis C virus (HCV). These peptides were later used successfully to develop a peptide‐based immunoassay (PBEIA) for the detection of HCV immunity. Peptides designed from the NS1 and NS4 protein regions were found to be very promising for the development of a new diagnostic kit to detect HCV infection in human blood. Peptide purity was tested by RP‐FPLC and the peptide identity was confirmed by amino acid analysis.
Splanchnic vasoconstriction by angiotensin II is arterial pressure dependent
Authors: Broomé M. , Åneman A. , Lehtipalo S. , Arnerlöv C. , Johansson G. , Winsö O. , Biber B.
Published: July 2002

Background: Our hypothesis was that splanchnic vasoconstriction by exogenous angiotensin II (Ang II) is significantly potentiated by local mechanisms increasing vasomotor tone and that splanchnic tissue oxygenation during administration of Ang II is perfusion pressure dependent. The aim was to study local splanchnic circulatory effects and tissue oxygenation during intravenous infusion of Ang II at different levels of regional arterial driving pressure in a whole‐body large animal model.

Methods: Ang II was infused in incremental doses (0–200 μg · h−1) in anaesthetised instrumented pigs (n=8). Mean superior mesenteric arterial pressure (PSMA) was adjusted by a local variable perivascular occluder. Perivascular ultrasound and laser‐Doppler flowmetry were used for measurements of mesenteric venous blood flow and superficial intestinal blood flow, respectively. Intestinal oxygenation was evaluated by oxygen tissue tension (PtiO2) and lactate fluxes.

Results: Ang II produced prominent and dose‐dependent increases in mesenteric vascular resistance (RSMA) when the intestine was exposed to systemic arterial pressure, but Ang II increased RSMA only minimally when PSMA was artificially kept constant at a lower level (50 mmHg) by the occluder. Although Ang II decreased PtiO2 at a PSMA of 50 mmHg, splanchnic lactate production was not observed.

Conclusion: We demonstrate that splanchnic vasoconstriction by exogenous Ang II is dependent on arterial driving pressure, suggesting significant potentiation through autoregulatory increases in vasomotor tone. Intestinal hypoxaemia does not seem to occur during short‐term infusion of Ang II in doses that significantly increases systemic arterial pressure.
Missense C168T in the Wiskott–Aldrich Syndrome protein gene is a common mutation in X‐linked thrombocytopenia
Authors: Ho Lye Lin , Ayling Juliet , Prosser Ian , Kronenberg Harry , Iland Harry , Joshua Douglas
Published: July 2002

We describe a large Syrian–Lebanese family who clinically manifest X‐linked thrombocytopenia (XLT). To date, five family members have undergone splenectomy with rapid and sustained normalization of their platelet numbers. Genomic analysis demonstrated that affected men in this cohort had the missense C168T (Thr45Met) mutation in exon 2 of the Wiskott–Aldrich Syndrome protein (WASp) gene. Exon 2 is the commonest site for mutations associated with XLT and mild forms of WAS, and the C168T missense mutation is the most frequent. Detection of this mutation by restriction enzyme digestion provides an efficient screening test for prompt identification and for assessment of female carrier status.
Effects of free fatty acids and acipimox, a lipolysis inhibitor, on the somatotroph responsiveness to GHRH in anorexia nervosa
Authors: Gianotti Laura , Fassino Secondo , Daga Giovanni Abbate , Lanfranco Fabio , De Bacco Carlotta , Ramunni Josefina , Arvat Emanuela , Maccario Mauro , Ghigo Ezio
Published: July 2002

OBJECTIVE

Anorexia nervosa is characterized by low IGF‐1 and high GH and free fatty acid (FFA) levels. As FFA exerts an inhibitory feedback action on GH secretion in physiological conditions, we hypothesized that somatotroph cells could be less sensitive to the negative feedback action of FFA in anorexia nervosa.

PATIENTS

Fifteen patients with anorexia nervosa (AN, age: mean ± SEM: 20·8 ± 1·2 years, BMI: 15·9 ± 0·3 kg/m2) and 12 normal female controls (NW, age 27·2 ± 2·1 years, BMI 21·2 ± 2·2 kg/m2).

MEASUREMENTS

We studied the effects of lipid‐heparin emulsion (Li‐He, Intralipid 10% 250 ml + heparin 2500 U iv from −60 to +90 minutes in seven AN and six NW) or acipimox (ACI, 250 mg p.o. at −60 minutes in eight AN and six NW), a lipolysis inhibitor, on the GH response to GHRH (1 µg/kg iv as a bolus at 0 minutes).

RESULTS

Basal IGF‐1 levels were lower (P<0·05) while GH levels were higher (P<0·05) in AN than in NW. On the other hand, basal FFA levels in the two groups were not significantly different. In both groups Li‐He increased FFA levels (P<0·05), which became higher (P<0·02) in AN than in NW. Li‐He infusion inhibited (P<0·05) basal GH levels in AN to levels overlapping those in NW. The GH response to GHRH in the whole AN group was higher than in NW (P<0·03). Li‐He inhibited the somatotroph responsiveness to GHRH in AN (P<0·03) as well as in NW (P<0·03) and during Li‐He the GH response to GHRH in AN became similar to that in NW. Whilst ACI pretreatment enhanced the GH response to GHRH in AN (P<0·02), it did not significantly increase that in NW. Interestingly, after ACI administration, FFA levels were inhibited in both groups (P<0·05) persisting higher in AN than in NW (P<0·05).

CONCLUSION

Though GH hypersecretion in anorexia nervosa occurs in presence of enhanced lipolysis, our present findings indicate that the sensitivity of somatotroph cells to the inhibitory feedback action of free fatty acid is preserved.