bluuebunny/crossref_metadata_2025 huggingface dataset:
Protection afforded by post-infection SARS-CoV-2 vaccine doses: A cohort study in Shanghai
Authors: Zheng Bo , Gonçalves Bronner P , Deng Pengfei , Wang Weibing , Tian Jie , Liang Xueyao , Yao Ye , Xue Caoyi
Published: February 2025

Background:

In many settings, a large fraction of the population has both been vaccinated against and infected by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Hence, quantifying the protection provided by post-infection vaccination has become critical for policy. We aimed to estimate the protective effect against SARS-CoV-2 reinfection of an additional vaccine dose after an initial Omicron variant infection.

Methods:

We report a retrospective, population-based cohort study performed in Shanghai, China, using electronic databases with information on SARS-CoV-2 infections and vaccination history. We compared reinfection incidence by post-infection vaccination status in individuals initially infected during the April–May 2022 Omicron variant surge in Shanghai and who had been vaccinated before that period. Cox models were fit to estimate adjusted hazard ratios (aHRs).

Results:

275,896 individuals were diagnosed with real-time polymerase chain reaction-confirmed SARS-CoV-2 infection in April–May 2022; 199,312/275,896 were included in analyses on the effect of a post-infection vaccine dose. Post-infection vaccination provided protection against reinfection (aHR 0.82; 95% confidence interval 0.79–0.85). For patients who had received one, two, or three vaccine doses before their first infection, hazard ratios for the post-infection vaccination effect were 0.84 (0.76–0.93), 0.87 (0.83–0.90), and 0.96 (0.74–1.23), respectively. Post-infection vaccination within 30 and 90 days before the second Omicron wave provided different degrees of protection (in aHR): 0.51 (0.44–0.58) and 0.67 (0.61–0.74), respectively. Moreover, for all vaccine types, but to different extents, a post-infection dose given to individuals who were fully vaccinated before first infection was protective.

Conclusions:

In previously vaccinated and infected individuals, an additional vaccine dose provided protection against Omicron variant reinfection. These observations will inform future policy decisions on COVID-19 vaccination in China and other countries.

Funding:

This study was funded the Key Discipline Program of Pudong New Area Health System (PWZxk2022-25), the Development and Application of Intelligent Epidemic Surveillance and AI Analysis System (21002411400), the Shanghai Public Health System Construction (GWVI-11.2-XD08), the Shanghai Health Commission Key Disciplines (GWVI-11.1-02), the Shanghai Health Commission Clinical Research Program (20214Y0020), the Shanghai Natural Science Foundation (22ZR1414600), and the Shanghai Young Health Talents Program (2022YQ076).
The domesticated transposon protein L1TD1 associates with its ancestor L1 ORF1p to promote LINE-1 retrotransposition
Authors: Kavaklıoğlu Gülnihal , Podhornik Alexandra , Vcelkova Terezia , Marjanovic Jelena , Beck Mirjam A , Phan-Canh Trinh , Mair Theresia , Miccolo Claudia , Drino Aleksej , Doni Mirko , Egger Gerda , Chiocca Susanna , Modic Miha , Seiser Christian
Published: February 2025

Repression of retrotransposition is crucial for the successful fitness of a mammalian organism. The domesticated transposon protein L1TD1, derived from LINE-1 (L1) ORF1p, is an RNA-binding protein that is expressed only in some cancers and early embryogenesis. In human embryonic stem cells, it is found to be essential for maintaining pluripotency. In cancer, L1TD1 expression is highly correlative with malignancy progression and as such considered a potential prognostic factor for tumors. However, its molecular role in cancer remains largely unknown. Our findings reveal that DNA hypomethylation induces the expression of L1TD1 in HAP1 human tumor cells. L1TD1 depletion significantly modulates both the proteome and transcriptome and thereby reduces cell viability. Notably, L1TD1 associates with L1 transcripts and interacts with L1 ORF1p protein, thereby facilitating L1 retrotransposition. Our data suggest that L1TD1 collaborates with its ancestral L1 ORF1p as an RNA chaperone, ensuring the efficient retrotransposition of L1 retrotransposons, rather than directly impacting the abundance of L1TD1 targets. In this way, L1TD1 might have an important role not only during early development but also in tumorigenesis.
A multi-scale CNN with atrous spatial pyramid pooling for enhanced chest-based disease detection
Authors: Bukhari Muhammad Abdullah Shah , Bukhari Faisal , Asif Muhammad , Aljuaid Hanan , Iqbal Waheed
Published: February 2025

We introduce a sophisticated deep-learning model designed for the early detection of COVID-19 and pneumonia. The model employs a convolutional neural network-integrated with atrous spatial pyramid pooling. The atrous spatial pyramid pooling mechanism enhances the convolutional neural network model’s ability to capture fine and large-scale features, optimizing detection accuracy in chest X-ray images. This improvement, along with transfer learning, significantly enhances the overall performance. By utilizing data augmentation to address the scarcity of available X-ray images, our atrous spatial pyramid pooling-enhanced convolutional neural network achieved a validation accuracy of 98.66% for COVID-19 and 83.75% for pneumonia, which beats the validation results of the other state of the art approaches (the metrics used for evaluation were accuracy, precision, F1-score, recall, specificity, and area under the curve). The model’s multi-branch architecture facilitates more accurate and adaptable disease prediction, thereby increasing diagnostic precision and robustness. This approach offers the potential for faster and more reliable diagnoses of chest-related conditions.
Butterflies (Lepidoptera: Papilionoidea) of Georgia (Caucasus): annotated review of regional butterfly fauna with vernacular names index, notes on distribution and phenology
Authors: Słowińska Iwona , Jonko Krzysztof
Published: February 2025

Background

It is well known that butterflies are valuable indicators of environmental quality, given their existence in various habitats. Collecting and regularly updating data on species richness, abundance, and distribution of all butterfly species in the country is crucial for effective monitoring and conservation efforts, which can ultimately help minimise biodiversity losses. Since the last publication of the Georgian butterfly list, there have been numerous reports registering taxonomic revisions, nomenclatural changes or providing several new butterfly “cryptic species” based on genetic research. In the following article, based on a review of various sources of data, including existing literature and new, unpublished data, we present an annotated regional checklist of butterflies of Georgia, a country that is a part of the Caucasus ecoregion representing one of 36 biodiversity “hotspots”.

Methods

A database with all reported species for Georgia was created by compiling information from critical reviews of all available literature reports, records submitted by contributors of three websites dedicated to butterfly fauna, and data deposited in the Global Biodiversity Information Facility (GBIF) database. Various specialised sources were used to extract vernacular species names (Georgian, Russian and English).

Results

The updated list of butterflies from Georgia includes 244 species of the superfamily Papilionoidea recorded from almost 600 different locations. Nearly 25% of the 244 species were considered rare and extremely rare, while at the same time being at risk of potential extinction. For each species, we present brief phenological information, distribution in Georgia/Caucasus, occurrence status in each region of the country, thumbnails (ventral and dorsal view), as well as a list of vernacular names in Georgian, Russian and English. Regarding species that are reported in the literature as new, uncertain, or questionable in Georgia, we provide the relevant comments. In comparison to the other republics of Transcaucasia (Armenia, Azerbaijan), we noted a similar number of species. Our studies provide a robust baseline of data for further exploration of the Lepidoptera fauna of Georgia. This foundation should help to fill in the gaps in knowledge regarding regional species distribution, phenology, and habitat requirements.
First wild boar density data from Araucaria forest in Patagonian Andes
Authors: Skewes Oscar , Kambas Annaluisa , Gädicke Paula , Keuling Oliver
Published: February 2025

As Sus scrofa is an invasive species in South America, it may have a significant impact on biodiversity. Evaluating this threat requires reliable data, and population density can serve as a critical measure. However, such data is currently lacking for the southern Andes region. To address this gap, we monitored wild boar density in the Villarrica National Park, located in the Andes of south-central Chile. This study area is notable not only for its challenging climatic conditions but also for its endangered Araucaria araucana forest, which provides abundant food resources during autumn seed fall. The density calculated for the entire study period was 1.4 individuals/km2, with no significant variation between cold and warm seasons. The encounter rate showed strongly monthly variations. Given that this represents the first density estimate for wild boar in this region, our findings emphasize the need for continued monitoring, particularly due to the potential threat to the ecosystem and the already endangered Araucaria forest.
Performance of Myocardial Work as a Marker of Ischemia in Dipyridamole Stress Echocardiography
Authors: Saad Ariel K. , Aladio José M. , Yaniuk José C. , Chavin Carolina , Lux Bárbara G. , Villalba Claudia N. , Volberg Verónica I. , Pérez de la Hoz Ricardo A.
Published: February 2025

Background: There is scarce evidence about the assessment of myocardial work during dipyridamole stress echocardiography (DSE).

Objective: The aim of the present study was to evaluate the performance of myocardial work during DSE and to define its differences between patients with and without myocardial ischemia.

Methods: This retrospective study included 30 patients; mean age was 69.9 ± 10 years and 45% were men.

Results: Eight patients (27%) presented ischemia. After dipyridamole infusion, global myocardial work index (GWI) and global constructive work (GCW) decreased in the groups with and without ischemia. In patients with ischemia, global wasted work (GWW) increased and global work efficiency (GWE) decreased. In patients without ischemia, GWW decreased while GWE remained unchanged or significantly improved.

Conclusions: In DSE myocardial ischemia was associated with increased GWW and decreased GWE. These findings warrant further studies to elucidate the responsible mechanisms.
New 2024 European Society of Cardiology Guidelines for the Management of Chronic Coronary Syndromes. Highlights and Comparison with Other Clinical Practice Guidelines
Authors: Caroli Christian
Published: February 2025

The new 2024 European Society of Cardiology (ESC) clinical practice guidelines for the management of chronic coronary syndromes (CCS) revise the previous 2019 version and the 2018 myocardial revascularization guidelines, so that they serve as a double document....The aim of this article is to highlight the state-of the-art in CCS and compare the selected classes of recommendations and levels of evidence with the previous versions of the guidelines developed by the ESC, American Heart Association (AHA) and American College of Cardiology (ACC).
Transthyretin Cardiac Amyloidosis. Development of a Prediction Model and Scoring Scale for Diagnosis: deteCCTAR score
Authors: Gobbo Magali Y. , Meretta Alejandro , Carvelli Ma Victoria , Elissamburu Pablo , Spaccavento Ana , Corneli Mariana , Rosa Daniel , Costabel Juan Pablo , Pérez Baliño Néstor A. , Masoli Osvaldo
Published: February 2025

Background: To verify the diagnosis of transthyretin cardiac amyloidosis (ATTR-CA) in its early stages, certain warning signs or "red flags" have been lately identified to guide suspicion. However, to date, there is little evidence regarding the diagnostic sensitivity and specificity of each red flag or whether there is any combination of variables that can reliably predict the presence of ATTR-CA.
Objective: The aim of this study was to develop a prediction model based on clinical, electrocardiographic and/or echocardiographic variables to establish a scoring scale to guide the diagnosis of ATTR-CA.
Methods: The medical records of 342 patients with cardiac scintigraphy (CS) for suspected ATTR-CA were analyzed: 171 patients with a positive diagnosis were compared with the same number of patients with a negative diagnosis. Clinical, electrocardiographic and echocardiographic data were analyzed and included in univariate and multivariate logistic regression models. A 0-8 scoring scale was built and a receiver operating characteristic (ROC) curve was generated. The area under the curve (AUC) with its 95% CI was then calculated.
Results: The following variables were identified as predictors of ATTR-CA in univariate and multivariate logistic regression models: interventricular septum (IVS) ≥16 mm (OR 3.64, 95% CI 1.87-7.1), male gender (OR 7.91, 95% CI 3.7-17.1), grade II or III diastolic dysfunction with pseudonormal or restrictive relaxation pattern (OR 12.7, 95% CI 6.1-26.3), and history of bilateral carpal tunnel syndrome (CTS) (OR 24.4, 95% CI 6.1-97.9). Based on the OR obtained, a scoring scale was created showing an AUC of 0.88 (95% CI 0.84-0.91, p<0.001), and a value ≥3,
with high sensitivity and specificity, was identified to predict ATTR-CA (AUC 0.82 95% CI 0.77-0.87).
Conclusions: The prediction model allowed the development of a scoring scale that demonstrated high sensitivity and specificity to strongly guide the diagnosis of ATTR-CA.
Optimization of Growth and Yield of Glutinous Corn with the Application of Amelioran Formulation Plus Mycorrhza on Sandy Soil
Authors: Astiko Wahyu , Sudirman  , Fauzi Mohamad Taufik , Ernawati Ni Made Laksmi , Muthahanas Irwan
Published: February 2025

Aims: This study aimed at optimizing the growth and yield of glutinous corn through the application of an ameliorant formulation enriched with biological mycorrhizal fertilizer on sandy soil.
Study Design: The research was carried out using a Randomized Block Design. 
Place and Duration of Study: The research was conducted in Telaga Wareng Village, Pemenang Barat District, North Lombok Regency, Indonesia.
Methodology: Five ameliorant treatments tested were: F1: 75% cow manure + 25% biological mycorrhizal fertilizer, F2: 75% compost + 25% biological mycorrhizal fertilizer, F3: 75% "fertile" fertilizer + 25% biological mycorrhizal fertilizer, F4: 75% rice husk charcoal + 25% biological mycorrhizal fertilizer, and F5: 20% cow manure + 20% compost + 20% "fertile" fertilizer + 20% rice husk charcoal + 20% biological mycorrhizal fertilizer. Each treatment was repeated four times, resulting in 20 experimental plots. The observed parameters were plant height, number of leaves, wet and dry biomass weight per plant, wet and dry cob weight per plot, soil nutrient concentrations (total nitrogen and available phosphorus), nutrient uptake (nitrogen and phosphorus), mycorrhizal spore count, root colonization, and crop yield. Data were subjected to Analysis of Variance and where necessary followed by Honestly significant Different test at 5% level of significant.
Results: The 20% mixed ameliorant formulation (F5) produced the best results, significantly (P<0.05) optimizing the growth and yield of glutinous corn. This treatment improved plant height, biomass weight, cob weight and length, soil nutrient concentrations (total nitrogen and available phosphorus), nutrient uptake, mycorrhizal spore count, and root colonization.
Conclusion: The application of a 20% mixed ameliorant formulation consisting of cow manure, compost, "fertile" fertilizer, rice husk charcoal, and biological mycorrhizal fertilizer significantly (P<0.05) enhanced growth, yield, and soil nutrient utilization efficiency in glutinous corn grown on sandy soil.
Epidemiological Association between Oral Diseases and COVID-19: Pulpitis as a Key Risk Factor
Authors: Lopez-Hernandez Daniel , Brito-Aranda Leticia , Liceaga-Perez Liliana Grisel , Beltran-Lagunes Luis , Hernandez-Ramirez Geovanna Elizabeth , Thompson-Bonilla Maria del Rocio , Castro-Diaz Alaina Mariana , León-Jiménez Rita Gabriela , Vazquez-Sanchez Alberto , Melgarejo-Estefan Emmanuel , Torres-García Edgar Esteban , Flores-Gonzalez Francisco Javier , Salinas-Palacios Perla Veronica , Ortega-Lopez Julio Cesar , Hernandez-Almazan Maria Clara , Soto-de-la-Cruz Pilar , Flores-Morales Guadalupe Jacqueline , Fuentes-Torres Gabriela Patricia , Salas-Morales Alma Selene
Published: February 2025

Aims: To establish a possible association between pulpitis and COVID-19.
Study Design:  A descriptive, cross-sectional and retrospective study with an analytical approach was designed.
Place and Duration of Study: Ambulatory Care Medical Unit. The study was conducted from January 1st to July 31st, 2024, with Mexican patients attending outpatient consultations in the Dentistry, and the Family Medicine Specialty and General Medicine departments at the "División del Norte" Family Medicine Clinic, ISSSTE, in Mexico City, Mexico. The data was collected from January to December, 2022.
Methodology: Data on health and sociodemographic variables were collected through a retrospective design, using medical records from the Medical Financial Information System “SIMEF system”.
Results: We included 13,359 adult patients, mainly females (n=8,510; 63.7%) and people in their sixties (n=3,637; 27.3%). The average age was 61.76 years old (SD=12.65, median age=61 [IQR=52-71]). The most prevalent diseases were: hypertension (4,682; 35.0%), type 2 diabetes (3,502; 26.2%), COVID-19 virus identified (1,970; 14.7%), hyperlipidaemia (1,255; 9.4%), and obesity due to excess of calories (1,222; 9.1%). The average age of the 48 patients with irreversible pulpitis was 57.33 years old (SD=9.99 years, median age= 57 [IQR=49.25-62]). The majority of patients were females (n=29, 60.4%) and older adults between 50 and 59 years old (n=15, 31%). The logistic regression models showed associations with: sex (female) OR=1.196 (1.080-1.323), p=0.001; age (years) OR=0.920 (0.915-0.925), p<0.001; anomalies of dental arch relationship OR=0.399 (0.185-0.859), p=0.019; dentofacial functional anomalies OR=0.486 (0.262-0.902), p=0.022; temporomandibular joint disorders OR=0.620 (0.386-0.998), p=0.049; retained dental root OR=0.273 (0.111-0.672), p=0.005; disorders of teeth and supporting structures OR=0.407 (0.189-0.877), p=0.022; jaws’ alveolitis OR=11.573 (1.049-127.692), p=0.046; and pulpitis OR=2.198 (1.047-4.614), p=0.037.
Conclusion: These findings have shown epidemiological associations between oral conditions and COVID-19, and indicated that pulpitis is an associated risk factor. This supports the notion that oral conditions may play a significant role in modulating the risk of SARS-CoV-2 infection and the development of COVID-19, potentially through genetic and epigenetic mechanisms related to inflammatory and immunological processes.
Biosynthesis of 3β‐hydroxy‐5,7‐pregnadien‐20‐one by the horse fetal gonad
Authors: Tait A.D. , Hodge L.C. , Allen W.R.
Published: July 2002

The production of equilin and the other ring B‐unsaturated estrogens by the pregnant mare is anomalous in that they are biosynthesised by a cholesterol‐independent pathway. Fetal horse gonads were incubated with tritiated sodium acetate and radiochemically pure 3β‐hydroxy‐5,7‐pregnadien‐20‐one and 3β‐hydroxy‐5,7‐androstadien‐17‐one were isolated. A fetal gonad‐placental system is proposed for equilin production, 3β‐hydroxy‐5,7‐pregnadien‐20‐one being a precursor for 3β‐hydroxy‐5,7‐androstadien‐17‐one in the fetal gonad and the latter being the precursor of equilin in the placenta. The nature of the possible precursor of 3β‐hydroxy‐5,7‐pregnadien‐20‐one is discussed.
Electrochemistry of ubiquinones
Authors: Prince Roger C. , Leslie Dutton P. , Malcolm Bruce J.
Published: July 2002

First and second half‐wave reduction potentials of a series of 1,4‐benzo‐ and 1,4‐naphtho‐quinones related to the naturally occurring ubiquinones, plastoquinones and menaquinones are correlated with substituent effects. Notably, E

of 2,3‐dimethoxy‐1,4‐benzoquinone is positive of the values for the 2,5‐ and 2,6‐dimethoxy isomers, and of the value for methoxy‐1,4‐benzoquinone. This phenomenon is attributed to steric inhibition of resonance when two methoxy groups occupy adjacent positions, and the significance of this orientation in the ubiquinone series is highlighted.
A light‐stimulated increase of cyclic GMP in squid photoreceptors
Authors: Saibil Helen R.
Published: July 2002

Photoreceptor outer segments isolated from squid retina are known to contain a light‐activated GTP‐binding protein. Here it is shown that these photoreceptors contain around 0.01 mol cyclic GMP per mol rhodopsin. Adding GTP in the dark stimulates the production of 0.0003–0.001 mol cyclic GMP/mol rhodopsin per min. GTP and light cause a 2‐fold faster increase in cyclic GMP. These results show that either (1) squid rhodopsin activates a guanylate cyclase, or (2) there is a constant guanylate cyclase activity and photoexcited rhodopsin inhibits a cyclic GMP phosphodiesterase.
Inhibition of 2'‐phosphodiesterase by cAMP‐dependent protein kinase
Authors: Itkes A.V. , Kartasheva O.N. , Kafiani C.A. , Severin E.S.
Published: July 2002

2'‐Phosphodiesterase from NIH 3T3 cells was purified about 530‐fold. Treatment of the cell lysate with the cAMP‐dependent protein kinase causing the 2'‐phosphodiesterase inhibition did not result in phosphorylation of the enzyme itself. The kinase was found to phosphorylate a specific 18‐kDa protein, the phosphorylated form of this protein being the inhibitor of 2'‐phosphodiesterase.
Absorption changes of Photosystem II donors and acceptors in algal cells
Authors: Lavergne Jérome
Published: July 2002

Flash‐induced absorption changes were measured in the 390–450 nm region, using whole cells of a double mutant strain of Chlorella sorokiniana, lacking PS I centers and part of the pigment antenna. Spectral changes associated with PS II acceptors (Qa and Qb) and donors (p680, Z and L) are described. In this region, the spectrum obtained for Qb
−/Qb differs markedly from that of Qa
−/Qa. Different spectra were also obtained for the secondary donor (Z+/Z) when measured after one or three flashes.
Inner and outer complexes of Pt‐coordination compounds with DNA probed by SERS spectroscopy
Authors: Séquaris J.-M. , Koglin E. , Malfoy B.
Published: July 2002

Surface enhanced Raman scattering (SERS) spectroscopy has been used to study the interfacial behaviour of DNA modified by cis‐Pt(NH3)2Cl2, (cis‐DDP) and [Pt‐(dien)Cl]Cl bidentate and monodentate platinum coordination compounds, respectively. Two stereochemical configurations of Pt‐DNA complexes can be deduced from the adsorption behaviour of the Pt adducts. The antitumoral inactive [Pt‐(dien)Cl]Cl forms an outer complex whereas the antitumoral active cis‐DDP favours an inner complex.
Degradation of actin and vimentin by calpain II, a Ca2+‐dependent cysteine proteinase, in bovine lens
Authors: Yoshida Haruko , Murachi Takashi , Tsukahara Isamu
Published: July 2002

Calpain II, a high Ca2+‐requiring form of Ca2+‐dependent cysteine proteinase (EC 3.4.22.17), isolated from bovine lens was found to cleave actin and vimentin, two major cytoskeletal elements of the lens. Polyacrylamide gel electrophoresis revealed that actin (M
r 43000) was broken down through intermediary products of approximate M
r 42000 and 40000, while vimentin (M
r 57000) was rapidly cleaved into several fragments ranging from M
r 44000 to 20000. The cleavage was dependent on Ca2+ and could be blocked by calpastatin, a calpain‐specific inhibitor. These findings suggest that calpain might play a role in age‐related degradation of the lens cytoskeleton.
Complete amino acid sequence of γ‐subunit of the GTP‐binding protein from cattle retina
Authors: Ovchinnikov Yu.A. , Lipkin V.M. , Shuvaeva T.M. , Bogachuk A.P. , Shemyakin V.V.
Published: July 2002

The complete amino acid sequence of the γ‐subunit of the GTP‐binding protein from cattle retina has been established. The polypeptide chain of the γ‐subunit consists of 69 amino acid residues and contains the unusual sequence Cys35‐Cys36. The M
rof the γ‐subunit is 8008.7.
Transcriptional control of thyroglobulin gene expression by cyclic AMP
Authors: Van Heuverswyn B. , Leriche A. , Van Sande J. , Dumont J.E. , Vassart G.
Published: July 2002

Transcription of thyroglobulin (Tg) gene is under the positive control of thyrotropin (TSH). The mechanism of this control has been further investigated. Rats were treated with triiodothyronine (T3) to decrease their endogenous TSH production. Following the intravenous injection of bovine TSH, a 3‐fold stimulation of Tg gene transcription could be detected in isolated nuclei as early as 1 h after treatment. The TSH effect was also observed in tissue fragments incubated in vitro under conditions where a concomitant stimulation of cAMP accumulation was detected. Forskolin, a universal activator of adenylate cyclase, was able to mimic TSH action on Tg gene transcription. We conclude that TSH controls transcription of Tg gene directly via its known interaction with receptors on thyrocytes and that cAMP is a physiological mediator of this effect.
Purification of arogenate dehydrogenase from Phenylobacterium immobile
Authors: Mayer Esther , Waldner-Sander Sylvia , Keller Brigitte , Keller Eberhard , Lingens Franz
Published: July 2002

Phenylobacterium immobile, a bacterium which is able to degrade the herbicide chloridazon, utilizes for L‐tyrosine synthesis arogenate as an obligatory intermediate which is converted in the final biosynthetic step by a dehydrogenase to tyrosine. This enzyme, the arogenate dehydrogenase, has been purified for the first time in a 5‐step procedure to homogeneity as confirmed by electrophoresis. The M
r of the enzyme that consists of two identical subunits amounts to 69000 as established by gel electrophoresis after cross‐linking the enzyme with dimethylsuberimidate. The K
m values were 0.09 mM for arogenate and 0.02mM for NAD+. The enzyme has a high specificity with respect to its substrate arogenate.
Tissue‐specific modulation of the mitochondrial calcium uniporter by magnesium ions
Authors: Favaron Marco , Bernardi Paolo
Published: July 2002

This paper analyzes the kinetics of the Ca2+ uniporter of mitochondria from rat heart, kidney and liver operating in a range of Ca2+ concentrations near the steady‐state value (1–4μM). Heart mitochondria exhibit the lowest activity, and physiological Mg2+ concentrations inhibit the mitochondrial Ca2+ uniporter by approx. 50% in heart and kidney, and by 20% in liver. At physiological Ca2+ and Mg2+ concentrations the external free Ca2+ maintained by respiring mitochondria in vitro is higher in heart and kidney with respect to liver mitochondria. This behaviour could represent an adaptation of different mitochondria to their specific intracellular environment.
Localization of light‐induced conformational changes in bovine rhodopsin
Authors: Pellicone Chantai , Nullans Gérard , Virmaux Noëlle
Published: July 2002

Conformational changes in the extradiscal regions of rhodopsin induced by illumination were investigated by modifying the visual pigment by mild treatment with cyanogen bromide prior to and after light exposure. Light induced an increased yield of cleavage of the Met bond 253‐254 and a new cleavage at the Met bond 155–156 of the rhodopsin polypeptide chain. These residues, located at the beginnings of the membrane‐buried helices 6 and 4, respectively, were concluded to become extradiscally exposed upon illumination.
Oxygen from water is coordinated to manganese in the S2 state of photosystem II
Authors: Hansson Örjan , Andréasson Lars-Erik , Vänngård Tore
Published: July 2002

Oxygen ligands from water are bound to the manganese cluster giving rise to the ‘multiline’ EPR signal from the S2 state of photosystem II, as shown by the observation of hyperfine broadening of the EPR signal in the presence of 17O‐enriched water. The binding must occur in the S0, S1 or S2 state. The estimated upper limit for the 17O hyperfine coupling constant, 0.5 mT, excludes Superoxide and hydroxyl radicals in the S2 state, but not peroxide.
Circular dichroism studies on the signal sequence of E. coli alkaline phosphatase indicate the presence of both α‐helix and β‐structure in hydrophobic environments
Authors: Reddy G.Laxma , Nagaraj R.
Published: July 2002

The conformations of a synthetic peptide corresponding to the signal sequence of E. coli alkaline phosphatase, Lys‐Gln‐Ser‐Thr‐Ile‐Ala‐Leu‐Ala‐Leu‐Leu‐Pro‐Leu‐Leu‐Phe‐Thr‐Pro‐Val‐Thr‐Lys‐Ala‐OCH3, have been examined in different environments by circular dichroism spectroscopy. In trifluoroethanol, methanol and aqueous mixtures of these solvents, the signal peptide has largely random conformation (~80%) with small amounts of a‐helix and β‐structure. However, in micellar environment, there is a significant increase in ordered conformation with both α‐helix and β‐structure being present, unlike in other signal sequences reported in the literature, where only the α‐helical conformation has been observed. Hence, an α‐helical conformation may not be as stringent a requirement as overall hydrophobicity for recognition of signal sequences by the cell's export machinery.
Evidence for a dual function of the herbicide‐binding D1 protein in photosystem II
Authors: Metz James G. , Pakrasi Himadri B. , Seibert Michael , Arntzer Charles J.
Published: July 2002

The LF‐1 mutant of the green alga Scenedesmus obliquus is completely blocked on the oxidizing (water‐splitting) side of photosystem II (PS II) while the reaction center and reducing side remain functional. A 34‐kDa protein found in the PS II reaction center core complex of wild‐type cells is replaced by a 36‐kDa protein in the mutant cells. Both of these proteins are labeled by azido[14C]atrazine and are recognized by polyclonal antibodies raised against the herbicide‐binding, D1 protein of Amaranthus hybridus. The data provide a new perspective on the role of the D1 protein by implying that it affects the oxidizing side of PS II in addition to performing its well established function on the reducing side.
Why is uncompetitive inhibition so rare?
Authors: Cornish-Bowden Athel
Published: July 2002

Enzyme kinetics
Uncompetitive inhibition
Catastrophic response
Pesticide design
Voltage‐dependent and multi‐state ionic channels induced by trichorzianines, anti‐fungal peptides related to alamethicin
Authors: Molle G. , Duclohier H. , Spach G.
Published: July 2002

The ionophore properties of two peptaibols of the trichorzianine family have been investigated in planar lipid bilayers and compared to those of alamethicin. Macroscopic conductance experiments reveal voltage‐dependent channels only in the thinnest membranes and a greater efficiency of the neutral analog. In single‐channel experiments, a multi‐state behaviour, consistent with the usual barrel‐stave model, is disclosed but the discrete current fluctuations are much more rapid than for alamethicin. The results indicate a stringent requirement for the helix length/bilayer thickness match in agreement with a previous model and suggest the design of new synthetic peptides.
The influence of culture medium composition on drug metabolising enzyme activities of the human liver derived Hep G2 cell line
Authors: Doostdar H. , Duthie S.J. , Burke M.D. , Melvin W.T. , Grant M.H.
Published: July 2002

When grown in the standard Dulbecco's medium the human liver derived Hep G2 hepatoma cell line shows only 10–20% of the cytochrome P‐450‐dependent mixed function oxidase (MFO) activity of freshly isolated human adult hepatocytes. However, the MFO activities and, to a lesser extent, the activities of UDP‐glucuronyltransferase and glutathione‐S‐transferase can be increased by altering the composition of the growth medium. Modified Earle's medium was more effective in this respect than Williams' E medium and increased the O‐dealkylations of ethoxyresorufin, benzyloxyresorufin and pentoxyresorufin 50‐, 30‐ and 10‐fold, respectively.
Orientation and assignment of the four cytochrome hemes in Rhodopseudomonas viridis reaction centers
Authors: Vermeglio André , Richaud Pierre , Breton Jacques
Published: July 2002

Low temperature absorption and linear dichroism measurements on oriented reaction centers of Rhodopseudomonas viridis at different redox potentials allow the α‐bands of the four hemes to be spectrally resolved. The high‐potential heme C556 presents an α‐band split into two components absorbing at 555 and 551 nm. The corresponding linear dichroism spectrum shows two transitions of opposite sign and equal amplitudes. Comparison of our experimental results with the linear dichroism values calculated from the atomic coordinates leads us to assign unambiguously the high‐potential C556 cytochrome with heme 2, the third heme away from the primary donor. Taken together with other available spectroscopic observations, this result implies the following sequence for the redox centers in Rhodopseudomonas viridis: C554 C556 C552 C559 P.
Cytochrome o (bo) is a proton pump in Paracoccus denitrificans and Escherichia coli
Authors: Puustinen Anne , Finel Moshe , Virkki Marika , Wikström Mårten
Published: July 2002

Spheroplasts from aerobically grown wild‐type Paracoccus denitrificans cells respire with succinate despite specific inhibition of the cytochrome bc
1 complex by myxothiazol. Coupled to this activity, which involves only b‐type cytochromes, there is translocation of 1.5–1.9 H+/e− across the cytoplasmic membrane. Similar H+ translocation ratios are observed during oxidation of ubiquinol in spheroplasts from aerobically grown mutants of Paracoccus lacking cytochrome c oxidase, or deficient in cytochrome c, as well as in a strain of E. coli from which cytochrome d was deleted. These observations show that the cytochrome o complex is a proton pump much like cytochrome aa
3 to which it is structurally related.
A putative protein of a growth specific cDNA from BALB/C‐3T3 cells is highly similar to the extracellular portion of mouse interleukin 1 receptor
Authors: Tominaga Shin-ichi
Published: July 2002

A cDNA clone, which represents a species of mRNA that is expressed in growth‐stimulated BALB/c‐3T3 cells but not in resting cells, was found to encode a protein remarkably similar in sequence to the members of the immunoglobulin superfamily, especially to the extracellular portion of the mouse interleukin 1 receptor. The immunoglobulin superfamily is believed to be involved in cell adhesion and cell‐to‐cell interaction. The evidence that a member of this family is induced in the course of the initiation of cell proliferation is intriguing.
Synthetic polymeric sialoside inhibitors of influenza virus receptor‐binding activity
Authors: Matrosovich M.N. , Mochalova L.V. , Marinina V.P. , Byramova N.E. , Bovin N.V.
Published: July 2002

Anomeric aminobenzylglycosides of Neu5Ac were coupled with the polyacrylate carrier and a number of synthetic polyvalent sialosides obtained were investigated as inhibitors of influenza virus attachment. The inhibitory activity of polymeric sialosides is highly dependent upon the Neu5Ac residue content and the nature of the carrier. The polyacrylic acid based polymer bearing 10 mol% of Neu5Ac is 3 orders of magnitude more potent inhibitor than the corresponding monovalent benzylsialoside and considerably more active than fetuin.
Stopped‐flow fluorescence kinetic studies of Glu‐plasminogen Conformational changes triggered by AH‐site ligand binding
Authors: Christensen Ulla , Molgaard Lone
Published: July 2002

Binding of 6‐aminohexanoic acid to the AH‐site, a weak lysine binding site in Glu‐plasminogen, alters the conformation of the molecule. The kinetics of the binding and the accompanying conformational change are investigated at pH 7.8. 25°C. Changes of intrinsic protein fluorescence were measured as a function of time after rapid mixing in a stopped‐flow apparatus. The results reflect a two‐step reaction mechanism: Rapid association of Glu‐plasminogen and 6‐aminohexanoic acid (K
1 = 44 mM) followed by the conformational change (k
2 = 69 g−1 and k
−2 = 3 g−1) with on overall dissociation constant K
4 = 2.0 mM, Thus the conformational change is rather fast, t

= 0.01 g. Its importance for the rates or Glu‐plasminogen activation reactions is discussed.
Pyrophosphate‐dependent phosphofructokinase, an anaerobic glycolytic enzyme?
Authors: Mertens Emmanuel
Published: July 2002

Recent evidence indicates that in as diverse organisms as unicellular eukaryotes, higher plants and prokaryotes, anaerobic glycolysis relies on a pyrophosphate‐dependent phosphofructokinase instead of the classical ATP‐dependent enzyme. This difference in phosphoryl donor specificity does not necessarily reflect a primitive metabolism, as thought earlier, but could rather be the result of convergent evolution, fostered by the energetic advantage conferred to the cell when glycolysis is the sole source of ATP.
Oligo(2′‐O‐methyl)ribonucleotides Effective probes for duplex DNA
Authors: Shimizu Miho , Konishi Aritomo , Shimada Yasuaki , Inoue Hideo , Ohtsuka Eiko
Published: July 2002

To find novel probes for duplex DNA, we prepared four types of triplexes containing a homopurine‐homopyrimidine 15‐mer duplex DNA, and examined their thermal stabilities (T
m values). The single strands used for triplex formation were a DNA 15‐mer having a defined C‐T mixed sequence, and its sugar‐modified analogs, namely 2′‐fluoro DNA, RNA, and 2′‐O‐methyl RNA. The 2′‐O‐methyl RNA and the RNA‐containing triplexes were similar in their enhanced stabilities at pH 6.1 and, amongst the four triplexes, the 2′‐O‐methyl was the most stable at pH 5.0. Furthermore, an experiment using a 34‐mer duplex DNA suggested that the 2′‐O‐methyl RNA‐triplex was destabilized, mostly as a result of the incorporation of a mismatched triplet, as compared to the DNA triplex counterpart. Thus, 2′‐O‐methyl RNA can serve as an effective probe for duplex DNA.
The Alzheimer‐like phosphorylation of tau protein reduces microtubule binding and involves Ser‐Pro and Thr‐Pro motifs
Authors: Gustke N. , Steiner B. , Mandelkow E.-M. , Biernat J. , Meyer H.E. , Goedert M. , Mandelkow E.
Published: July 2002

Tau protein can be transformed into an Alzheimer‐like state by phosphorylation with a kinase activity from brain [Biernat et al. (1992) EMBO J. 11, 1593–1597]. Here we show that the phosphorylation at Ser‐Pro motifs strongly decreases tau's affinity for Microtubules. The major reduction occurs during the first of the three main stages of phosphorylation. The data explain the lower Stability of microtubules resulting from the pathological tau phosphorylation.
Heat and cold denaturation of β‐lactoglobulin B
Authors: Azuaga Ana I. , Galisteo Maria L. , Mayorga Obdulio L. , Cortijo M. , Mateo Pedro L.
Published: July 2002

The thermal denaturation of bovine β‐lactoglobulin B was investigated by high‐sensitivity differential scanning microcalorimetry between pH 1.5 and 3.0 in 2OmM phosphate buffer. The process was found to be a reversible, two‐state transition. Progressive addition of guanidine hydrochloride at pH 3.0 leads to the appearance of a low‐temperature calorimetric endotherm, corresponding to the cold renaturation of the protein. Circular dichroism experiments have confirmed the low and high temperature denaturation processes, and have shown some structural differences between both denatured states of β‐lactoglobulin B.
Expression of Kv2.1 delayed rectifier K+ channel isoforms in the developing rat brain
Authors: Trimmer James S.
Published: July 2002

Mammalian central neurons regulate a diverse set of functions by changes in spatial and temporal expression patterns of a large family of K+ channel gene products. Here the temporal patterns of expression of Kv2.1 (drkl) K+ channel mRNAs and polypeptides have been studied in rat brain. Northern blots using Kv2.1‐specific probes show that three size classes (4.4, 9.0, 11.5 kb) of Kv2.1 K+ channel transcripts are present in rat brain. These mRNAs show differential patterns of expression over embryonic and postnatal developmental, with the 4.4 kb transcript being the predominant embryonic Kv2.1 mRNA, and the 11.5 kb transcript being the predominant adult mRNA. Immunoblots using Kv2.1‐specific site‐directed antibodies show the existence of multiple Kv2.1 polypeptides, which differ in their mobility on SDS polyacrylamide gels, in their immunoreactivity to a carboxyl terminal‐directed anti‐Kv2.1 antibody, and in their developmental expression. Thus Kv2.1 polypeptide isoforms exhibit discrete temporal patterning during neuronal development, implying distinct roles for these channel proteins in vivo.
ATP ‐ a fast neurotransmitter
Authors: Edwards Frances A. , Gibb Alasdair J.
Published: July 2002

ATP receptor‐mediated responses in peripheral and central neurones have many characteristics which suggest that ATP may act as a fast neurotransmitter. While the receptors underlying these responses have properties which are similar to other ligand‐gated ion channels which mediate fast neurotransmision, the nature of their calcium permeability and the rapid breakdown of ATP to adenosine may confer unique properties on ATP mediated synaptic transmission. The evidence that ATP acts as a fast neurotransmitter is reviewed and the properties of ATP and its receptor channels are discussed in terms of synaptic transmission.
Immunogold localization of glutathione transferase B1‐1 in Proteus mirabilis
Authors: Allocati Nerino , Cellini Luigina , Aceto Antonio , Iezzi Teresa , Angelucci Stefania , Robuffo Iole , Di Ilio Carmine
Published: July 2002

By using the immunolabelling technique, the cellular localization of glutathione transferase in Proteus mirabilis was investigated. Evidence was obtained indicating a significant higher content of glutathione transferase in the periplasmic than cytoplasmic space. This result further support the idea that bacterial glutathione transferase is involved in xenobiotic detoxication.
Elongation factor‐2 kinase: effective inhibition by the novel protein kinase inhibitor rottlerin and relative insensitivity towards staurosporine
Authors: Gschwendt Michael , Kittstein Walter , Marks Friedrich
Published: July 2002

The elongation factor‐2 (eEF‐2) is selectively phosphorylated by the eEF‐2 kinase (calmodulin‐dependent kinase III). This phosphorylation can be inhibited by calmodulin antagonists, such as CGS 9343B (IC5o = 4 μM). The novel protein kinase inhibitor rottlerin is shown to suppress eEF‐2 phosphorylation with an IC50 of 5.3 μM. By contrast, the eEF‐2 kinase is rather resistant towards the potent but non‐selective protein kinase inhibitor staurosporine (IC50> 50 μM) and thus can be differentiated from most other protein kinases that are suppressed by staurosporine in the nM range.
Differential activation of STATs 3 and 5 during mammary gland development
Authors: Philp Janet A.C. , Burdon Thomas G. , Watson Christine J.
Published: July 2002

We have investigated the activity of STAT family members throughout a mammary developmental cycle. Transcripts for Stat 5 were upregulated during pregnancy whilst STAT1 and STAT3 mRNAs were expressed at constant levels. DNA binding complexes containing both STAT5a and 5b showed differing affinities for two naturally occurring STAT5 binding sites. In the involuting mammary gland STAT5 activity decreased whereas STAT3 was specifically activated. These observations reveal a complex pattern of activation of STAT factors during mammary growth, differentiation and remodelling and provide the first evidence for the involvement of STAT3 in development of the mammary gland.
Principal-component analyses of PANSS and SANS-SAPS in schizophrenia: their stability in an acute phase
Authors: Dollfus S , Petit M
Published: July 2002

Whether studies agree or disagree on the positive-negative dichotomy in schizophrenia, the relevance of a third component, disorganization, remains a point of debate. Disorganization, as expressed by the scale for the assessment of negative symptoms and positive symptoms (SANS-SAPS) and the positive and negative syndrome scale (PANSS) principal-component analyses, could be considered as permanent and determinant a dimension as the positive and negative components. The aim of this study therefore was to determine whether this disorganization, with the negative and positive components, is stable and has the same composition in the acute and postacute phases of illness. This study was carried out in 57 patients, broadly defined by at least one of four diagnostic criteria (American Psychiatric Association, Langfeldt, Carpenter and Schneider), established with a computerized checklist, and evaluated with SANS-SAPS and PANSS. Principal component analyses (PCA) of these scales were performed at admission and discharge from hospital.

The PCA of SANS-SAPS displayed a 3-factor solution, regardless of the phase of illness (acute or postacute), showing that the negative, positive and disorganization components were stable. The PCA of PANSS yielded negative and positive components perfectly stable over time and a disorganization component whose composition varied between admission and discharge. At admission, this component included the conceptual disorganization item negatively correlated with one of depression. At discharge, this disorganization component included two additional items, autistic preoccupation and mannerisms and one depression component appeared. The instability of the PCA of PANSS could express the role played by the phase of illness; in an acute phase, this disorganization component was constituted by more “positive” items such as grandiosity, unusual thought content and active social avoidance whereas in the postacute phase, it included items that reflected more the chronicity of the illness, such as mannerisms and autistic preoccupation. Moreover, the depressive item appeared, in the postacute phase, in a specific depressive component. This result could be due to the fact that depressive symptoms cannot be expressed when positive symptoms are very severe, which explains why no depressive components were shown during the acute phase.
LEAP‐1, a novel highly disulfide‐bonded human peptide, exhibits antimicrobial activity
Authors: Krause Alexander , Neitz Susanne , Mägert Hans-Jürgen , Schulz Axel , Forssmann Wolf-Georg , Schulz-Knappe Peter , Adermann Knut
Published: July 2002

We report the isolation and characterization of a novel human peptide with antimicrobial activity, termed LEAP‐1 (liver‐expressed antimicrobial peptide). Using a mass spectrometric assay detecting cysteine‐rich peptides, a 25‐residue peptide containing four disulfide bonds was identified in human blood ultrafiltrate. LEAP‐1 expression was predominantly detected in the liver, and, to a much lower extent, in the heart. In radial diffusion assays, Gram‐positive Bacillus megaterium, Bacillus subtilis, Micrococcus luteus, Staphylococcus carnosus, and Gram‐negative Neisseria cinerea as well as the yeast Saccharomyces cerevisiae dose‐dependently exhibited sensitivity upon treatment with synthetic LEAP‐1. The discovery of LEAP‐1 extends the known families of mammalian peptides with antimicrobial activity by its novel disulfide motif and distinct expression pattern.
Intracellular trehalose improves osmotolerance but not desiccation tolerance in mammalian cells
Authors: Garcı́a de Castro Arcadio , Tunnacliffe Alan
Published: July 2002

Trehalose has been shown to play a role in osmotolerance or desiccation tolerance in some microorganisms, anhydrobiotic invertebrates and resurrection plants. To test whether trehalose could improve stress responses of higher eukaryotes, a mouse cell line was genetically engineered to express bacterial trehalose synthase genes. We report that the resulting levels of intracellular trehalose (∼80 mM) are able to confer increased resistance to the partial dehydration resulting from hypertonic stress, but do not enable survival of complete desiccation due to air drying.