Elucidating experiences of faculty members in applying effective teaching strategies in the online class during the COVID-19: A qualitative study

BACKGROUND

Despite the restrictions on providing medical courses online in medical universities, all instructors were required to provide training on virtual platforms. This study aimed to explain faculty members' experiences applying effective strategies in online class teaching.

MATERIALS AND METHODS

This study has been done with a qualitative approach and using the method of conventional content analysis. Participants included 14 faculty members working at the Shiraz University of Medical Sciences. Semistructured interviews were used to collect data. Faculty members who had experience in conducting online classes were purposefully selected. Graneheim and Lundman's (2004) approach was used to analyze interview data.

RESULTS

Two main categories were obtained from the data analysis: interpersonal communication and supportive behavior. The category of interpersonal communications comprises the subcategories of emotional expression and flexibility. The category of supportive behavior includes the subcategories of educational design, learner encouragement, diversity in evaluation, collaborative learning, and prompt feedback.

CONCLUSION

Our findings confirmed that an appropriate teaching strategy leads to better attention to class and deep learning in learners. The cause is that in online classes, the student's attention is more minor than in daily classes due to its virtual nature. Appropriate educational strategies will motivate learners, interest them, and improve teacher interaction. These strategies increase students' participation in educational activities.

Effect of temperature and propylene glycol as a cosolvent on dissolution of clotrimazole

Herein, the solubility study of clotrimazole was performed in a propylene glycol+water system. The solubility values were fitted to various cosolvency equations. The model accuracies were studied with the computation of the mean relative deviations. The thermodynamic behavior was investigated according to the van't Hoff and Gibbs equations for clotrimazole in the propylene glycol+water system. Furthermore, the density data for clotrimazole were determined in mixtures of propylene glycol+water and fitted to the Jouyban-Acree equation.

Comparing the effects of self- care education by lecture and smartphone application on self-efficacy of patients with thalassemia

BACKGROUND

Patients with the thalassemia have a basic requirement for self-efficacy regarding their treatment procedure. The present study aimed to compare the effect of self-care education via a smartphone application and lectures on the self-efficacy of patients with thalassemia.

METHODS

In the present quasi-experimental study, 99 patients with thalassemia at Shahid Beheshti Hospital in Yasuj, Iran, in 2019 who were eligible to enter the study, were selected. The block randomization was done with the block sizes of 3, 6, and 9, and participants were randomly assigned to 3 groups: smartphone application (A), lecture intervention (B), and control (c). Smartphone application and lecture interventions were performed for intervention groups A and B, respectively, during 8 weeks. Scherer's self-efficacy measure was used to collect the data at baseline and eight weeks after the intervention. Data were analyzed by SPSS-version 25 software using Paired t-test, Wilcoxon and Kruskal-Wallis tests.

RESULTS

Ninety-nine patients with thalassemia with a mean (SD) age of 25 (6) and 58 females (58.59%) participated in the present study. The results indicated a significant difference in self-efficacy among 3 groups after intervention (P = 0.001). However, self-care education with smartphone application revealed a significant increase in the mean (SD) of self-efficacy of the patients with thalassemia 68.36(8.45) compared to the lecture method 62.55 (7.3) (P = 0.003) and control 62.09 (6.7) (P = 0.001). There were no significant differences among the self-efficacy scores of the patients in lecture intervention and control groups.

CONCLUSIONS

The results revealed that smartphone application was a suitable educational software to promote self-efficacy in patients with thalassemia. It is recommended to use smartphone application methods to improve the self-efficacy levels of patients with thalassemia.

Phylogenetic Diversity of Dermanyssus gallinae (Dermanyssidae) based on Mitochondrial Cytochrome Oxidase-1 Gene Sequence Collected from Different Bird Species in Iran

A wide range of hosts, especially birds, can be infested with Dermanyssus gallinae (D. gallinae), as an obligate hematophagous mite. In this study, cytochrome oxidase 1 (CO1) gene sequences were employed to perform molecular and phylogenetic analyses of D. gallinae collected from different bird species in Iran. Adult mites were collected from the body surface and cage material of ornamental and wild birds in industrial farms located in the Western and Northwestern regions of Iran. The infestation was identified in layer poultry farming by inspecting the eggs and the whole surfaces of the birds' bodies. The holding area and body surface of the ornamental and wild birds were also thoroughly examined. The D. gallinae samples were assigned to two subgroups of haplogroup A (i.e., A1 and A2). The phylogenetic tree suggested that the D. gallinae samples collected from wild birds in the A1 sub-haplogroup should be placed beside Japanese, Norwegian, Italian, and French samples isolated from wild birds in the A2 sub-haplogroup. Additionally, the highest phylogenetic similarity in the A2 sub-group was observed between mites isolated from ornamental and industrial birds in Australia. The findings of the present study suggest that crows and sparrows may play an important role in the transmission of D. gallinae infestation to other species of wild birds due to their high population, as well as their presence in most areas.

Exploration challenges of the implementers of Iran's transformational innovation plan in medical education

BACKGROUND

The Health System Reform Plan, especially in medical education, has undoubtedly caused changes in the university. The continuation of this project requires recognizing the challenges confronted by those in charge of its implementation. This study aimed to explore the challenges of the implementers of the Transformation and Innovation Plan in Medical Education in the universities of Macroregion 5.

MATERIALS AND METHODS

The qualitative research was conducted using the content analysis method. Semi-structured interviews with health and medical education managers were used to collect information. Participants were 11 educational leaders of universities who were selected by purposeful sampling. Data collection continued until data saturation was reached. Data analysis was performed continuously and simultaneously with data collection. The Graneheim and Lundman methods were used to analyze the data.

RESULTS

From 11 interviews, one theme, five categories, and 12 subclasses were obtained. Five categories include lack of proper groundwork, weak leadership, structural problems, inability to fund, and inadequate monitoring.

CONCLUSION

Innovation and transformation in medical education are one of the critical missions and admirable actions of the Ministry of Health in the field of education, but a review of this plan can, in addition to identifying shortcomings and problems, pave the way for success, and progress in future programs.

A dual-signaling electrochemical ratiometric strategy combining "signal-off" and "signal-on" approaches for detection of MicroRNAs

A dual-signaling electrochemical ratio metric strategy was developed for detection microRNA-18a based on the duplex-specific nuclease-assisted target recycling and electrochemical atom transfer radical polymerization signal amplification. In the presence of target microRNA, RNA/DNA duplexes are formed, which become the substrate of the duplex-specific nuclease-assisted target recycling. Hence only the DNA strand is cleaved by duplex-specific nuclease enzyme, resulting in the throw away of methylene blue (MB) from the electrode (signal off) accompanied by releasing of target microRNA, which can be recycled in the next hybridization. The remaining piece of capture DNAs on the electrode surface hybridize with the Azide labeled-signal DNAs. "Click reactions" were carried out between 3-Butynyl-2-bromoisobutyrate and Azide to initiate the electrochemical atom transfer radical polymerization reaction. This process could bring a great number of ferrocenylmethyl methacrylate (FMMA) on the surface of electrode (signal on). The I_FMMA/I_MB value was proportionate to the microRNA-18a concentration and measured by square wave voltammetry. The promising potential of the proposed biosensor in clinical analyses was exhibited by its remarkable features such as strong performance, high specificity, agreeable storage stability, and notable selectivity in real sample evaluation with no pretreatment or amplification. Finally, our biosensing method offers such an application to be used for the early clinical diagnosis of Pancreatic Cancer.

OP0146 TENOSYNOVITIS, SYNOVIAL HYPERTROPHY AND FEET BURSITIS ARE USEFUL ULTRASOUND BIOMARKERS FOR PREDICTING ARTHRITIS DEVELOPMENT IN A POPULATION AT-RISK FOR RHEUMATOID ARTHRITIS

Background:

Musculoskeletal ultrasound (MSUS) evaluation of individuals at risk for developing rheumatoid arthritis (RA) having Anti-Citrullinated Protein Antibody (ACPA) positivity and musculoskeletal complaints, may play an important role in the very early detection of RA.

Objectives:

We aimed to identify which ultrasound markers could predict arthritis development.

Methods:

Individuals with musculoskeletal complaints with a positive anti-CCP2 test were referred to the rheumatology department for a detailed clinical (68 joint count) and MSUS examination of the hands, feet and any symptomatic joints. Only those without clinical and/or MSUS detected arthritis were included in the RISK RA prospective cohort and followed-up over 3 years/ or until arthritis onset. Using EULAR-OMERACT guidelines1, MSUS markers for synovial hypertrophy (SH) and hyperemia (Doppler activity) were documented for each visit. Finger and wrist tendons were screened for any signs of tenosynovitis (TS), and between metatarsal joints for bursitis. Association of MSUS biomarkers with arthritis development was tested (comparing proportions) using Chi-Squared or Fisher’s exact tests.

Results:

288 individuals were included from January 2014 to October 2019 (79% female, 35% RF positive, median age 48 years: IQR: 36-58). Within a median of 38 months (IQR: 1-72) since recruitment, 84 individuals (28%) developed an arthritis diagnosis.

Prior to obtaining any diagnosis (at inclusion and/or follow-up visit), 95 of the 288 individuals (33%) had at least one type of MSUS anatomical modification present (around the tendons, joint synovium and/or within bursal cavities), and 56% (53/95) of these individuals eventually developed arthritis. Of the remaining 193 that did not present with any obvious MSUS changes, 16% progressed towards arthritis development.

The presence of tenosynovitis was detected in 64 of 288 individuals scanned prior to diagnosis and were more frequent in those developing arthritis (44%, 37/84) as compared to those with TS not developing arthritis (13%, 27/204), p<0.0001. The extensor carpi ulnaris wrist tendons were mostly involved. Sonographic changes within the synovium were noted in 11% (32/288) of all individuals, mostly affecting the metacarpophalangeal (MCP) and metatarsophalangeal (MTP) joints. There was a higher incidence of synovial hypertrophy detected in those developing arthritis (22%, 18/24), as compared to those that remained arthritis free (7%, 14/204), p<0.0001. The MCP joints with synovial hypertrophy were more prone to arthritis development as compared to the MTP’s. Furthermore, we observed a higher frequency of bursitis between the MTP joints in individuals developing arthritis, as compared to individuals having a bursitis who did not develop arthritis (13%, 11/84 versus 7%, 14/204, p=0.009).

Conclusion:

Ultrasound biomarkers such as tenosynovitis of the extensor carpi ulnaris, synovial hypertrophy of the MCP joints and feet bursitis have good potential to predict arthritis development in a population at-risk for rheumatoid arthritis.

References:

[1]Maria-Antonietta D’Agostino et al. RMD Open 2017;3:e 000428

Acknowledgements:

All study participants and patients, including researchers that are part of the multidisciplinary laboratory, clinical and academic teams of the RISK RA study group, as well as all assisting this research in one form or the other are greatly acknowledged.

Disclosure of Interests:

None declared

The effect of coronavirus (COVID-19) pandemic on medical sciences education in Iran

BACKGROUND

COVID-19 has a great impact on medical sciences education. Some researches have been conducted on the effects of the COVID-19 pandemic on medical sciences education in the world. The aim of this study was to identify the effects of this disease on medical sciences education in Iran.

MATERIALS AND METHODS

This futures study research was carried out using the future wheel method in Iran's University of Medical Sciences in the spring of 2020. A semi-structured interview was also conducted on the vice chancellors of medical sciences universities, faculty presidents, faculty vice chancellors, faculty members, medical education specialists, and university students, who were purposefully identified. The interview continued until achieving data saturation. Analysis of the interviews was performed by MAXQDA version 10 software.

RESULTS

The effects were presented at three levels including primary effects, secondary effects, and third effects. In addition, 16 primary effects, 51 secondary effects, and 24 tertiary effects were recognized. One primary effect of the coronavirus (COVID-19) pandemic on medical sciences education in Iran was fear, stress, and anxiety among students and faculty members as well as staffs to get the disease. In addition, rumor was circulated concerning the infection of some people, thus, there was a need for holding courses regarding stress management and rumor management. One secondary effect of the coronavirus (COVID-19) pandemic on medical sciences education in Iran was allocation of a number of educational hospitals to the referral hospitals of COVID-19. One tertiary effect of the coronavirus (COVID-19) pandemic on medical sciences education in Iran was increasing the number of virtual courses.

CONCLUSIONS

The most important effect of this disease on medical sciences education is the postponement of practical and apprenticeship classes, and consequently the increased length of the academic term that leads to delay in the students' graduation, which can reduce the workforce. On the one hand, this disease causes death of a number of students, educational and medical staffs, and faculty members, as well as reduces the workforce. Also, lengthening the recruitment of faculty members will add to this challenge. In this regard, there is a need to plan to compensate for the shortage of required human resources.

SAT0584 SPECIFIC ACPA REACTIVITIES AND INFLAMMATORY BIOMARKERS ALONG WITH ULTRASOUND TENOSYNOVITIS ARE ASSOCIATED WITH ARTHRITIS ONSET IN A POPULATION AT RISK FOR RHEUMATOID ARTHRITIS

Background:

Anti-citrullinated protein antibodies (ACPA) are characteristic markers for rheumatoid arthritis (RA), developing years before disease onset. Early clinical and biological biomarkers could provide useful information on the onset of RA in predisposed individuals.

Objectives:

The aim of the study was to investigate whether ACPA along with inflammatory markers and musculoskeletal ultrasound changes could predict arthritis development in individuals at risk for RA.

Methods:

ACPA-positive individuals with musculoskeletal complaints were referred from primary care to a rheumatology clinic, recruited in the Risk-RA research program and followed-up for up to 3 years, between April 2014 and October 2019. All individuals lacked arthritis both at clinical examination by a trained rheumatologist and ultrasound assessment of hands and feet and any other symptomatic joints (according to EULAR-OMERACT definition). Blood samples were collected at inclusion and were analyzed for 15 ACPA fine specificities (by custom made peptide array), 92 inflammation-associated protein biomarkers (by multiplex immunoassay with Olink extension technology) and HLA-SE (DR low resolution kit). Statistical analysis used univariate and multivariate models with backwards selection and cox regression.

Results:

268 individuals with a median age of 48 (36-58) were recruited, out of which 212 (79%) were females. 75 (28%) developed arthritis within 11 months of follow-up while the median follow-up for those not developing arthritis was 21 months (14-28). Increased ACPA levels, shorter symptom duration and RF positivity were the main differences between individuals developing arthritis and those who did not. In univariate models, the presence of HLA-SE, specific ACPA reactivities, certain inflammatory markers and ultrasound-detected tenosynovitis were associated with arthritis development. In multivariate analysis the presence of anti-cit-fillagrin (HR 2.1 (95% CI 1.2-3.7, p 0.01), IL6 levels (HR 1.4 (95% CI 1.2-1.7, p 0.0001) and tenosynovitis (HR 2.9 (95% CI 1.7-5.0, p 0.0001) remained significant predictors for arthritis onset.

Conclusion:

Certain ACPA reactivities together with inflammatory markers and ultrasound-detected tenosynovitis predict arthritis development in predisposed individuals for developing RA.

Disclosure of Interests:

None declared

Strengths of Iran for internationalization of medical sciences education

INTRODUCTION

Internationalization of higher education involves mutual exchanges as well as a consensus based. Political, economic, sociocultural, and scientific reasons recommend the need to move toward the internationalization of higher education. The current study highlights the strengths of the internationalization of Iran's medical sciences education.

MATERIALS AND METHODS

This descriptive exploratory study was carried out in 2016-2017 in Iran. The techniques used for data collection included review of articles, interview with subject experts, and the focus group and the nominal technique group to explore the views of various stakeholders. The data were analyzed with the qualitative content analysis method.

RESULTS

The inductive qualitative content analysis of all data generated 13 categories and 88 subcategories. The categories were geographical and geostrategic position of Iran; the historical, cultural, religious, and tourist attractions of Iran; the security of Iran; priority to internationalization policies and programs in Iran's macro plans; the existence of regulations, laws, and approvals for international activities; same language with neighboring and regional countries; the low cost of studying and living in Iran; the ability of Iranian faculty members and experts for internationalization; the background, reputation, and the progress of medical education, health, and care in Iran; the cheaper forces of Iran and their welcome to foreigners; the existence of motivation, zeal, and belief for internationalization; the existence of proper infrastructure; and the existence of a suitable capacity for internationalization.

CONCLUSIONS

Iran has some positive points that can be used to promote international activities, provided it does some good advertising in this regard. It is suggested that the challenges, opportunities, and threats to Iran's internationalization should be collated from the perspective of the various stakeholders.

Iran's international collaborative articles in medical sciences

Background: Forecasting is the process of predicting future behavior. In reviewing databases, no predicted value associated with international collaboration publications in Iran was found. Thus, the present study aimed at forecasting Iran’s international collaborative articles in medical sciences.

Methods: The number of Iran’s articles and international collaborative articles in medical sciences written over 56 years was extracted from SCOPUS. Data were extracted from 1960 up to 2016. The time series method was used for forecasting using the Minitab software Version 17.

Results: There was no increase in the number of medical articles from Iran from 1960 to 2001. However, the data showed incremental growth between 2001 and 2016. This was similar to Iran’s medical sciences international collaboration articles. In 2016, the percentage of Iran’s international collaboration articles was 15.2, which is expected to reach 19.9 in 2025.

Conclusion: An investigation was performed on the number of international collaboration articles in the field of medical sciences in Iran. Future trends show an incremental growth. The number of Iran’s articles can be increased with international cooperation. However, an increase or decrease in Iran’s articles without international cooperation has to be investigated.

Internationalization or globalization of higher education

INTRODUCTION

Studies about globalization and internationalization demonstrate different attitudes in explaining these concepts. Since there is no consensus among Iranian specialists about these concepts, the purpose of this study is to explain the concepts of internationalization and globalization in Iran.

MATERIALS AND METHODS

This study is a systematic review done in the first half of 2016. To explain the concept of globalization and internationalization, articles in Scientific Information D atabase, Magiran database, and Google Scholar were searched with the keywords such as globalization, scientific exchange, international cooperation, curriculum exchange, student exchange, faculty exchange, multinational cooperation, transnational cooperation, and collaborative research. Articles, used in this study, were in Persian and were devoted to internationalization and globalization between 2001 and 2016. The criterion of discarding the articles was duplicity.

RESULTS

As many as 180 Persian articles were found on this topic. After discarding repetitive articles, 64 remained. Among those, 39 articles mentioned the differences between globalization and internationalization. Definitions of globalization were categorized in four categories, including globalization, globalizing, globalization of higher education, and globalizing of higher education. Definitions about internationalization were categorized in five categories such as internationalization, internationalization of higher education, internationalization of the curriculum, internationalization of curriculum studies, and internationalization of curriculum profession.

CONCLUSION

The spectrum of the globalization of higher education moves from dissonance and multipolarization to unification and single polarization of the world. One end of the spectrum, which is unification and single polarization of the world, is interpreted as globalization. The other side of the spectrum, which is dissonance and multipolarization, is interpreted as globalizing. The definition of internalization is the same as that of globalizing. In other words, it is possible to say that internalization is similar to globalizing but different from globalization.

Modification of Source Strength in Low-Dose-Rate Lung Brachytherapy with 125I and 103Pd Seeds

BACKGROUND

A new treatment approach for most patients who have undergone early stage non-small-cell lung carcinoma (NSCLC) is wedge resection plus permanent implant brachytherapy. However, the specification of dose to medium at low energies especially in heterogeneous lung is unclear yet.

OBJECTIVE

The present study aims to modify source strength for different configurations of 125I and 103Pd seeds used in lung permanent implant brachytherapy.

METHODS

Different arrays of 125I and 103Pd seeds were simulated by MCNPX code in protocol-based water vs. actual 3D lung environments. Absorbed dose was, then, scored in both mediums. Dose differences between both environments were calculated and source strength was modified for the prescription point. In addition, lung-to-water absorbed dose ratio was obtained and presented by precise equations.

RESULTS

Due to significant differences in prescription dose, source strength was modified 16%-19% and 37%-43% for different configurations of 125I and 103Pd seeds, respectively. In addition, depth-dependent dose differences were observed between the actual lung and protocol-based water mediums (dose difference as a function of depth).

CONCLUSION

Modification of source strength is essential for different arrangements of 125I and 103Pd seeds in lung implantation. Modified source strength and presented equations are recommended to be considered in future studies based on lung brachytherapy.

Role of ruminants in the epidemiology of Echinococcus granulosus in Tabriz area, Northwest of Iran

Hydatidosis is a widespread zoonotic disease with a worldwide distribution. This disease produces significant financial losses and it remains a serious health problem in a number of countries. Hydatidosis results from ingesting the eggs of Echinococcus granulosus, and the developing larvae envelop themselves in a cyst which forms in the organs of the intermediate hosts. The aim of this study was to investigate the prevalence of cystic echinococcosis in sheep, cattle, buffalo, and goats, slaughtered in the Tabriz Abattoir, Northwest of Iran. From April 2012 to April 2013, out of 14828 slaughtered animals examined for CE (hydatidosis) in liver and lungs (5000 sheep, 6125 cattle, 1103 buffaloes and 2600 goats), 25.57% were infected. The rates of CE in lungs and liver were 15.2% and 7.18% in sheep, respectively, 15.30% and 9.73% in goats, respectively, 18.71% and 9.61% in cattle, respectively and 15.68% and 11.24% in buffaloes, respectively. The infection rate was higher in lungs and was more pronounced in cattle (P<0.05). There were significant differences found in the prevalence rates of the various ruminants, and also between the sexes (P<0.05). The findings of the present study revealed that lungs were the main infected tissue, and male animals were less likely to be infected than female animals. The infection rates of the different ruminants increased significantly with age, (P<0.05).

Vesicle permeabilization by purified soluble oligomers of prion protein: a comparative study of the interaction of oligomers and monomers with lipid membranes

The conversion of normal cellular prion protein (PrP) into its pathological isoform, scrapie PrP, may occur at the cell surface or, more probably, in late endosomes. The early events leading to the structural conversion of PrP appear to be related to the presence of more or less stable soluble oligomers, which might mediate neurotoxicity. In the current study, we investigate the interaction of alpha-rich PrP monomers and beta-rich size-exclusion-chromatography-purified PrP oligomers with lipid membranes. We compare their structural properties when associated with lipid bilayers and study their propensities to permeabilize the membrane at physiological pH. We also study the influence of the N-terminal flexible region (residues 24-103) by comparing full-length PrP(24-234) and N-terminally truncated PrP(104-234) oligomers. We showed that both 12-subunit oligomers cause an immediate and large increase in the permeability of the membrane, whereas equivalent amounts of monomeric forms cause no detectable leakage. Although the two monomeric PrP constructs undergo an alpha-to-beta conformational change when bound to the negatively charged membrane, only the full-length form of monomeric PrP has a weak fusogenic effect. Finally, the oligomers affect the integrity of the membrane differently from the monomers, independently of the presence of the N-terminal flexible domain. As for other forms of amyloidogenesis, a reasonable mechanism for the toxicity arising from PrP fibrillization must be associated with low-molecular-weight oligomeric intermediates, rather than with mature fibrils. Knowledge of the mechanism of action of these soluble oligomers would have a high impact on the development of novel therapeutic targets.

Prion protein oligomerization

The PrP propensity to adopt different structures is tightly linked to transmissible spongiform encephalopathies (TSE) which include Creutzfeldt-Jakob disease (CJD), Gerstmann-Sträussler-Scjeinker (GSS) and Kuru syndrome. In most cases, TSE is associated with the accumulation in the brain of an abnormally folded protease-resistant protein, PrP Sc or PrPres, which is derived from a cellular host-encoded protease-sensitive conformer, designated PrP C. The prion propagation in the brain is postulated to occur via a conformational change of PrP C into the amyloidogenic form PrP Sc, characterized by a high beta sheet content. The characterization of PrP SC oligomers as well as their biological activity is currently an area of active research. Indeed, PrP Sc structural diversity was proposed several years ago as a hypothesis to explain the origin of "prion strain" diversity. As prion pathologies belong to protein miss-assembly diseases, investigation of PrP conformational dynamics and, more precisely, oligomerization pathways exploration will help to achieve a better understanding of the pathological events at the molecular level.

Characterization of a complex formed between human plasminogen and recombinant sheep prion: pressure and thermal sensitivity of complex formation

Scrapie is thought to be caused by one or more conformations of a proteinacious particle called a prion. The infectious form(s) is referred to as the scrapie form of the prion protein (PrPsc) whereas a benign form, the cellular conformer, is referred to as PrPC. The cellular conformation of the sheep prion protein formed a 1:1 complex with human plasminogen. The complex precipitated at 0 degrees C (Ksp = 17* 10(-12) M2). This precipitation reaction was sensitive to both temperature and pressure. When subjected to hydrostatic pressure the precipitate dissolved. At 25 degrees C the complex was soluble with a dissociation constant of about 10(-7) M as determined by isothermal titration calorimetry. Absorption, fluorescence and circular dichroism spectroscopy showed that neither protein, in the complex, underwent a detectable structural change so long as proteolytic inhibitors were present. In the absence of proteolytic inhibitors, plasminogen slowly cleaved the prion protein.

Selective prion protein binding to synaptic components is modulated by oxidative and nitrosative changes induced by copper(II) and peroxynitrite in cholinergic synaptosomes, unveiling a role for calcineurin B and thioredoxin

Choline acetyltransferase (ChAT) and choline transport are decreased after nitrosative stress. ChAT activity is altered in scrapie-infected neurons, where oxidative stress develops. Cellular prion protein (PrPc) may play a neuroprotective function in participating in the redox control of neuronal environment and regulation of copper metabolism, a role impaired when PrPc is transformed into PrPSc in prion pathologies. The complex cross-talk between PrPc and cholinergic neurons was analyzed in vitro using peroxynitrite and Cu2+ treatments on nerve endings isolated from Torpedo marmorata, a model of the motoneuron pre-synaptic element. Specific interactions between solubilized synaptic components and recombinant ovine prion protein (PrPrec) could be demonstrated by Biacore technology. Peroxynitrite abolished this interaction in a concentration-dependent way and induced significant alterations of neuronal targets. Interaction was restored by prior addition of peroxynitrite trapping agents. Cu2+ (in the form of CuSO4) treatment of synaptosomes triggered a milder oxidative effect leading to a bell-shaped increase of PrPrec binding to synaptosomal components, counteracted by the natural thiol agents, glutathione and thioredoxin. Copper(II)-induced modifications of thiols in several neuronal proteins. A positive correlation was observed between PrPrec binding and immunoreactive changes for calcineurin B and its partners, suggesting a synergy between calcineurin complex and PrP for copper regulation.

CD4+ T cell-mediated immunity against prion proteins

The prion protein (PrP(C)) is essential for susceptibility to transmissible spongiform encephalopathies. A specific conformer of this protein (PrP(Sc)) is, according to the 'protein only' hypothesis, the principal or only component of the infectious agent, designated prion. Transmission of prions between species is often inefficient, resulting in low attack rates and/or prolonged incubation times and is ascribed to a 'species barrier' caused by differences in the amino acid sequence of PrP between recipient and donor. In this report, we demonstrate that these differences in amino acid sequence result in presentation of distinct peptides on major histocompatibility complex class II molecules. These peptides result in activation of specific CD4+ T cells which leads to the induction of an effective immune response against foreign PrP as demonstrated by antibody production. Therefore, CD4+ T cells represent a crucial component of the immune system to distinguish between foreign and self PrP.

A new synthesis of 1-chloroalkynes

4-Unsubstituted isoxazolinones derived from the corresponding beta-ketoesters can be chlorinated and converted into 1-chloroalkynes upon treatment with sodium nitrite and ferrous sulfate in aqueous acetic acid.

Specific determination of the proteinase K-resistant form of the prion protein using two-site immunometric assays. Application to the post-mortem diagnosis of BSE

The aim of this work was to establish an immunological test suitable for specifically detecting PrPres in tissues from animals or humans developing TSEs. We chose to use as detection method a conventional two-site immunometric assay (sandwich immunoassay) because over the last 20 years this technique has clearly been shown to be more sensitive and specific than other tests. We have established numerous two-site immunometric assays based on the use of monoclonal antibodies and suitable for measurement of PrPsen in various mammalian species (human, bovine, ovine, mouse and hamster). A detection limit below 100 pg/ml was estimated from standard curves established using ovine recombinant PrP. PrPres was selectively detected by processing samples (currently brain homogenates) to enable specific purification and concentration of PrPres, which was finally solubilized by a strong denaturing treatment. This sample-processing procedure can be achieved within 30 minutes. The capacity of this test to detect bovine PrPres was estimated in the framework of an evaluation study organized by the Directorate-General XXIV of the European Commission during May 1999. On this occasion, a blind test on 1400 brain stem samples taken from either healthy (1000) or BSE-infected (300) cows demonstrated 100% sensitivity and specificity. In addition, dilution experiments showed that the test can significantly detect PrPres in homogenates diluted 1/300 and was at least as sensitive as a conventional bioassay performed on mice.

High yield purification and physico-chemical properties of full-length recombinant allelic variants of sheep prion protein linked to scrapie susceptibility

Sheep susceptibility to scrapie is governed by polymorphisms at two major sites, codons 136 and 171, of the prp gene. To get more insight into the prion protein (PrP) sequence-linked basis of differential scrapie susceptibility, a high yield one-step method for the purification (over 99% final purity) of the full-length recombinant sheep PrP was developed, based on the affinity of the conserved octapeptide repeats for transition-metal cations. Thermal and chemical denaturation experiments and limited proteolysis studies were performed on the natural variants (A136R171, V136Q171 and A136Q171) and a recombinant PrP mutated at position 136 (V136R171). Results revealed the influence of mutations in positions 136 and 171 on the folding thermodynamic parameters and on the conformation of the C-terminal domain. Together, our results show that the VQ cellular protein linked to higher scrapie susceptibility is intrinsically more compact and/or stable than the resistance-linked AR counterpart. This might lead to a lower in vivo clearance rate of VQ and a consequently higher probability of occurrence of pathological events.

Three distinct sub-nuclear populations of HMG-I protein of different properties revealed by co-localization image analysis

We have studied the nuclear distribution of the non-histone HMG-I protein by indirect immunofluorescence in several human and murine somatic cell lines and in growing mouse oocytes. We show that HMG-I, a high mobility-group protein which interacts in vitro with the minor groove of AT-rich B-DNA, is found exclusively in the nucleus and that this localization corresponds to a complex distribution. By comparing the HMG-I-dependent fluorescence signal with the chromatin density determined by Hoechst 33342 or propidium iodide staining, we present evidence for the existence of three HMG-I sub-populations whose contribution to the total fluorescence can be determined using a newly developed quantitative co-localization image analysis program: foci that correspond to regions of heterochromatin, intense dots located within decondensed chromatin, and a more diffuse component extending throughout the nucleoplasm. In addition, we show that these sub-populations differ in their sensitivity to nuclease digestion and in vivo displacement by the minor-groove binder Hoechst 33342. Finally, double immunolabeling of RNA polymerase II-dependent transcription and HMG-I shows that the intense dots are not correlated with sites of high transcriptional activity. We discuss the possibility that these three sub-populations reflect distinct and separable biological functions of the HMG-I protein.

A comparison of pentamorphone and fentanyl in balanced anaesthesia during general surgery

The purpose of our randomized, double-blind study of 64 unpremedicated healthy patients undergoing surgical procedures with a duration of at least 60 min was to compare 0.75 micrograms.kg-1 and 1 microgram.kg-1 pentamorphone with 5 micrograms.kg-1 and 7.5 micrograms.kg-1 fentanyl to determine which dose of opioid would reduce the requirement for isoflurane supplementation needed to maintain haemodynamic stability. At 21 points during the procedure, the haemodynamic variables of heart rate and systolic, diastolic, and mean arterial pressures were recorded. The use of isoflurane was quantified; the number of patients requiring inhaled anaesthetic, concentration peaks, MAC minutes, and duration of isoflurane use were noted. The number of equal-volume supplemental opioid analgesic doses, postoperative analgesics, occurrence of postoperative nausea, emesis, and antiemetic doses were compared. The four groups exhibited similar patient demographics, total dose of muscle relaxants, types of surgical procedures, and duration of surgery or anaesthesia. Haemodynamic variables were stable with no difference among the four study groups. The patients given pentamorphone demonstrated both delayed requirement (P < 0.05) and shorter duration (P < 0.05) of isoflurane supplementation. Patients given either 5 micrograms.kg-1 or 7.5 micrograms.kg-1 fentanyl needed isoflurane supplementation within 12 +/- 16 min and 12 +/- 17 min from induction respectively; while patients given either 0.75 micrograms.kg-1 or 1 microgram.kg-1 pentamorphone did not require isoflurane supplementation for 37 +/- 10 min and 43 +/- 26 min respectively.(ABSTRACT TRUNCATED AT 250 WORDS)