bluuebunny/crossref_metadata_2025 huggingface dataset:
Durnonovariaodus maiseyigen. et sp. nov., a new hybodontiform shark-like chondrichthyan from the Upper Jurassic Kimmeridge Clay Formation of England
Authors: Stumpf Sebastian , Etches Steve , Underwood Charlie J. , Kriwet Jürgen
Published: May 2021

A partial skeleton of a hybodontiform shark-like chondrichthyan from the Upper Jurassic Kimmeridge Clay Formation of Dorset, England, is described and designated as a new genus and species,Durnonovariaodus maiseyigen. etsp. nov. The holotype and only known specimen, which is represented by disarticulated splanchnocranial elements with associated teeth, a single dorsal fin spine, the pelvic girdle, as well as unidentifiable cartilage fragments, plus countless dermal denticles, exhibits a puzzling combination of dental and skeletal features, providing important new insights into the morphological and ecological diversity of hybodontiforms.Durnonovariaodusgen. nov. displays a unique set of dental characters, showing close morphological resemblance toSecarodusfrom the Middle Jurassic of England, which was erected for distinctive, strongly labio-lingually compressed multicuspid cutting teeth originally described asHybodus polyprion. Skeletally,Durnonovariaodusgen. nov. resemblesHybodusandEgertonodusin having a palatoquadrate with a palatobasal process and an ethmoidal articular surface, combined with the possession of dorsal fin spines ornamented with costae. Therefore, and given the absence of any conclusive phylogenetic framework,Durnonovariaodus maiseyigen. etsp. nov. is here tentatively referred to Hybodontidae until more complete material becomes available in order to enable a more reliable suprageneric identification. The holotype ofDurnonovariaodus maiseyigen. etsp. nov. contains two separate pelvic half-girdles, a feature previously considered as evolutionarily primitive among hybodontiforms. However, unfused pelvic half-girdles also occur in the supposedly closely related speciesHybodus hauffianusand may in fact have been more widely distributed among hybodontiforms than previously thought, thus rendering the phylogenetic utility of separated pelvic half-girdles for inferring hybodontiform interrelationships difficult and unresolved.
Alterations in mechanical muscle characteristics and postural control induced by tennis match-play in young players
Authors: Colomar Joshua , Corbi Francisco , Baiget Ernest
Published: May 2021

Background

Central and peripheric fatigue indicators are among the main reasons for performance decline following competition. Because of the impact of these factors on performance, how these variables are affected by match-play could be of interest, especially in young tennis players.

Objective

This study aimed to investigate alterations induced by a simulated tennis match on postural control and muscle characteristics in young tennis players.

Method

Seventeen male junior players took part in pre- and post-competition testing sessions performing postural control (displacement, speed and surface area of center of pressures) and muscle characteristics measurements (tone, stiffness, time to relaxation and elasticity). Between trials, participants played an 80-min simulated tennis match.

Results

No significant differences were observed in any of the tested variables. Moderate-to-large effect sizes (ES) for decreased stiffness and tone and greater time to relaxation were found between pre- and post-conditions in the right rectus abdominis (−9.8%, −4.4% and 7.8%; ES = 0.8, 0.54 and −0.85). Also, a decrease in tone was found in the right vastus medialis (−7.1%; ES = 0.56), while surface area of the center of pressures with eyes open showed trends towards increasing in post-match measurements (55.9%; ES = 0.56).

Conclusion

An 80-min simulated tennis match seems insufficient to elicit significant changes in postural control and mechanical muscle characteristics. Results suggest that physiological responses triggered by match-play were closer to those seen after a moderate activity than those present following a strenuous task.
An Initial Survey of Experience Activities for Health and Wellness Tourism: A Case of Qionglu Scenic Area, Xichang City, Sichuan Province
Authors: Yen Tsai-Fa , Li Chunbo , Li Runfa
Published: May 2021

Our country’s economy and society continue to develop. With the popularization of national education and the growth of per capita annual income, the people are paying more and more attention to experience situations, and the tourism industry has entered the era of experience economy. In addition, at the end of 2019, my country's population over 65 years old accounted for 11.4%, and the 60-year-old retired group accounted for 18.1% (approximately 253 million people). In fact, it has entered an aging society, and the demand for health tourism has become more intense. Therefore, the citizens' demand for experience and health tourism has become more obvious. How to meet the development needs of health and wellnesstourism under the background of experience economy is an extremely important research topic. The research purpose of this article is to explore the problems of health and wellness tourism experience projects from the perspective of experience marketing, and put forward corresponding suggestions. This study uses the well-known tourist destination in Panxi, China: Qionglu Scenic Area, XichangCity, Sichuan Province, to interview local tourists through in-depth interviews. A total of 20 effective interview samples are obtained and analyzed by content analysis. The results of the analysis show that the respondents’ perception of health and wellnesstourism is mostly to promote health tourism, which roughly conforms to the definition of health and wellness tourism. Secondly, in terms of health and wellness tourism experience activities, respondents prefer catering activities, and focus on mountain and water experience activities. Therefore, this research suggests that destination managers and operators should make good use of local natural resources and cultural characteristics of the Yi ethnic group, focus on developing mountain and water experience projects, highlight ethnic minority dining and cultural characteristics, and meet consumer health and tourism needs.
Traditional Architecture in Romanian Philately (IV): the Households from Ieud, Jurilovca, Mastacăn, Moișeni and Năruja
Authors: Cioruța Bogdan-Vasile , Pop Alexandru Leonard
Published: May 2021

The cultural heritage is not only represented by the historical architectural monuments, but also by the architecture of wooden churches or traditional houses. It must be seen as a valuable heritage that, through proper management, can become a source of community well-being. It is important to preserve traditional architecture. To be able to build or restore adapted to modern needs, and respect the local architectural specifics. In this context, the study tries to emphasize once again the beauty of traditional Romanian architecture. This time in terms of philately. We want to expose the architectural specifics from five areas – Ieud (Maramureș county), Jurilovca (Tulcea), Mastacăn (Neamț), Moișeni (Satu Mare) and Năruja (Vrancea). Using illustrated postcards, and other philatelic effects, scenes from the outside and inside of the households in question are presented. The results of the research itself, not numerous, can be reorganized in the form of thematic exhibitions. Such events can contribute to increasing the attractiveness of the area among tourists.
Health Complications in Patients Recovering from COVID-19: A Narrative Review of Post-COVID Syndrome
Authors: Pai Marcus Yu Bin , Park Andrew Seung Ho , Chen Bruno Fu Lon , Toma Juliana Takiguti , Pai Hong Jin
Published: May 2021

Introduction: Due to the unprecedented health and economic complications resulting from COVID-19, the coronavirus pandemic is currently a leading global health concern. COVID-19 poses significant health risks, life-threatening clinical conditions, and even mortality in affected individuals. Several associated complications have also arisen as a result of COVID-19, including mass hospitalization, the need for invasive ventilation and intensive care unit (ICU) support, delayed recovery from infection, and post-recovery health issues. Furthermore, the pandemic itself has created enormous panic, which in turn affects the mental health of COVID-19 patients, individuals who have recovered from the disease, and the general population.

Just over a year has now passed since the beginning of the global COVID-19 pandemic and in this time, over 110 million individuals have been infected worldwide. Post-infection recovery times and long-term complications are now becoming more apparent. Especially physical and mental health complications arising from post-COVID-19-infection, which prevent a return to a healthy lifestyle and everyday routine remain a critical issue.

Objective: The primary objective of this narrative review is to address this clinically relevant issue and overview the health complications commonly observed in individuals who have recovered from COVID-19.

Methods: An investigation was performed on online databases for relevant articles from 2020 until January 2021. Key index words used in search were post-covid, myalgia, fatigue, pain.

Results: Fatigue, myalgia (i.e., muscle pain), sleep disruptions, and mental health issues (e.g., anxiety and depression) are among the most reported post-recovery symptoms in patients recovering from the disease. The etiology and potential management of these health complications are discussed, considering recently published findings from COVID-19 patients as well as previous studies focusing on complications arising from other related pandemics.

Conclusion: Patients who have recovered from COVID-19 should be evaluated for signs of fatigue, muscle pain, mental health difficulties, and sleeping difficulties regardless of disease severity. Based on this review of the literature, complete clinical and psychiatric evaluation, and the use of validated indicators of the severity of COVID-19 disease, symptoms are recommended to develop efficient health management approaches that meet patients' needs.
Investigating the Effect of Metal Inert Gas Welding Parameters on AA10119 Mild Steel Quality by Taguchi Method
Authors: Ikimi Jephthah A. , Momodu Aigbovbiosa A. , Totore Erhuvwu
Published: May 2021

In welding, the quality of welded joints is greatly influenced by the welding process parameters. Thus, in order to achieve a good weld quality, there is exigency to select the right welding process parameters. The focus of this study is to investigate the effect of Metal Inert Gas (MIG) welding process parameters; welding current, welding voltage and welding speed on the tensile strength of mild steel AA10119 welded plates. The experiment was designed using Taguchi’s L9 orthogonal array with three levels. Kaierda MIG MAG Inverter CO2 Welder Model E-180 welding machine was used to conduct the experiments with three repetitions. From the analysis carried out by applying Taguchi’s method, the result shows that the welding speed and welding current have the most significant influence on tensile strength of the weld and an optimum parameter setting of A3B2C2 was suggested; welding current 240 A, welding voltage 25 V and welding speed 0.010 m/s. The mean tensile strength at this optimal setting A3B2C2 was predicted to be 442 N/mm2.
Effect of Silicon Die Condition on the Breaking Load Performance of a Dam and Fill Semiconductor Package
Authors: Talledo Jefferson
Published: May 2021

A semiconductor package has a silicon die on which an integrated circuit (IC) is fabricated. The die is singulated from a single wafer using processes like mechanical sawing or laser grooving. These processes have impact on the final condition of the silicon die after wafer singulation. This paper discusses a study on the effect of the die condition on the breaking load of a package with a dam and fills structure. The encapsulation material of this type of package has lower modulus when compared with the epoxy mold compound material used in most molded packages. The package breaking load was determined using 3-point bend test for two sets of packages. The first set of packages was assembled with silicon die produced using mechanical sawing. The second set was assembled with die produced using laser grooving. Results of the 3-point bend test showed that the breaking load of the package with die from mechanical sawing is higher compared with the package assembled with die from laser grooving. The study revealed that that the silicon die condition has significant effect on the robustness of the final package where the die is used.
Evaluation of the Effect of Jatropha integerrima (Euphorbiaceae) on the renal Function of Male Albino Wistar Rats Exposed to Chromium
Authors: Andy-Nwokocha M. J. , Nwachuku E. O. , Bartimaeus E. S. , Obunwo C. C.
Published: May 2021

Aim: The aim of the study was to evaluate the effect of Jathropha interrigima on renal function of male Albino Wistar rats exposed to chromium.

Study Design:  The study is an experimental study.

Place and Duration of Study: Department of Animal and Environmental Biology, Rivers State University, Port Harcourt, Nigeria, between March 2020 and December 2020.

Methodology: A total of 30 male Albino Wistar rats that weighed between 140-210g were used for this study. This study was done in three phases: Acute, Sub-chronic and Chronic phases and Jathropha interrigima extract was given to the rats as a prophylaxis (PRE) within the three phases and as a therapeutic (POST) substance within the three phases. Blood samples were collected at the end of each phase for both PRE and POST by cardiac puncture and separated into microvials tubes for the evaluation of the renal parameters listed above using a Selectra Pro-S automated chemistry analyzer. The kidneys were also harvested for histological studies using haematoxilin stain. Data was analysed using SPSS version 22.0 and p values less than 0.05 were considered statistically significant.

Results: For the Acute Phase, the rats exposed to Chromium (Treatment Group) given the Jathropha extract prophylactically(PRE) had mean Potassium level( 7.33 ± 0.51mmol/l) which was significantly higher than the positive control (5.5 ± 0.42mmol/l); whereas for the Treatment group given the Jathropha extract therapeutically (POST) had mean Sodium level (134.7 ± 2.08mmol/l) which was significantly higher than the negative control (126.5 ± 2.21mmol/l) and the positive control( 130.0 ± 0.01mmol/l), also a CRP level (1.6 ± 0.06u/ml) which was significantly higher than the PC ( 1.5±0.0u/ml1) and NC (1.3± 0.01u/ml) and a KIM level (16.7±0.10u/ml) which was significantly higher than the PC(14.3±0.01u/ml) and NC ( 1.3±0.01u/ml) respectively. In the Sub-chronic phase, Rats in the PRE had TG mean CRP (1.5±0.42u/ml) and KIM (16.1±1.72iu/l) which were significantly higher than the NC and PC (1.2±0.07); whereas those in POST had mean Potassium level (4.5 ± 0.20) which was significantly lower than PC and NC, a mean Bicarbonate level (20.0 ± 1.00) which was higher than PC and NC. And an Anion Gap (12.7 ± 0.58) which was significantly lower than the controls. Mean CRP, KIM, Urea and Creatinine levels in the treatment group where significantly lower than in the controls. A similar result occurred at the chronic phases for both PRE and POST.  

Conclusion: The results of this study indicate that exposure to Chromium caused a Renal injury and Jathropha interrigima may have the potential to heal or reverse the injurious effect if given as a therapy for upto 30 to 60 days.
Pharmacological and Toxicological Appraisal of Promising Enzyme-tyrosinase Isolated from Soil Bacteria-an Update
Authors: Ahmed Asma , Gill Kinza Rashid , Khan Hassan Akbar , Aman Sitwat , Qureshi Javed Anver , Mehmood Rafia
Published: May 2021

Aims: The membrane associated tyrosinase is an enzymatically active monomeric glycoprotein which is purified to only a low degree. It has gained importance in the present era due to its antioxidant and immunomodulatory properties as well as applications in industry. Moreover its role in the synthesis of melanin in skin for protection from UV radiations also paved the way towards the better understanding of this enzyme.

Study Design: Biochemical and molecular characterization of tyrosinase producing soil bacterium had been followed by the assessment of its antioxidant, cytotoxic and anti-cancer activities.

Place and Duration of Study: Whole work had been completed at the Microbiology and Molecular biology labs of IMBB during 2018- 2019.

Methodology: Tyrosinase producing species were identified by biochemical characterization followed by their genomic DNA sequencing and BLAST analysis while crude tyrosinase was characterized by Bradford's methods, tyrosinase activity and total protein activity, followed by their molecular characterization on SDS-PAGE. The antioxidant and free radical scavenging properties of tyrosinase were evaluated via DPPH, ABTS and FRAP assays and cell proliferation inhibition and the cytotoxicity was calculated via antitumor and MTT assays.

Results: P. putida, B. cereus, B. mycoides, M. luteus, K. pneumonia were found to be tyrosinase producing species while their SDS-PAGE analysis showed that the molecular mass of crude tyrosinase was about 39 kDa. Protein contents, total tyrosinase and specific tyrosinase activity was found to be highest in tyrosinase from B. mycoides [0.008±0.06 mg/ml, 1500±0.06 U/ml and 346820.8±0.03 U/mg of tyrosinase respectively]. The results of biological activities of crude tyrosinase vary from bacteria to bacteria. Tyrosinase from P. putida showed higher antioxidant [66.4±0.01% in DPPH assay, 32.04±0.06%in ABTS assay and 320.6±0.06 in FRAP assay], antitumor [67.8±0.01%] and cytotoxic activity [39±1.0% cell viability], followed by B. Cereus tyrosinase [64.7±0.06% antioxidant power in DPPH assay, 53.41±0.03% in ABTS assay and 159.6±0.06% in FRAP assay, 46.46±0.01% antitumor and 43±0.75% cell viability].

Conclusion: The study revealed that tyrosinase isolated from different bacterial strains depicted optimal percentage of anti-oxidative, anti-proliferative and cellular viability and can be used in the near future for medical and industrial purposes.
Topical Delivery of Apremilast Loaded Nanostructured Lipid Carrier Based Hydrogel for Psoriasis Therapy
Authors: Sindhoor S. M. , Koland Marina
Published: May 2021

Background: Apremilast (APR) is an orally administered selective phosphodiesterase 4 inhibitor approved to treat plaque psoriasis and psoriatic arthritis and is available as an oral tablet formulation. However, its systemic side effects limit its application. The low solubility and permeability of apremilast make it difficult to administer it through the skin. Hence an attempt is made to incorporate apremilast into a suitable nanocarrier to facilitate its topical delivery.

Aims: To formulate and characterize Apremilast loaded nanostructured lipid carriers for the management of psoriasis to reduce the systemic side effects.

Methodology: Apremilast loaded Nanostructured Lipid carriers (NLC) were prepared by melt emulsification accompanied by probe sonication. The formulation was prepared using GMS, Sefsol 218, Tween 80 and Transcutol P as Solid Lipid, Liquid lipid, Surfactant and Penetration Enhancer. The NLC was incorporated into carbapol 934 dispersion to convert it into a gel. The NLC formulation was evaluated for size, Polydispersity Index, Zeta Potential, Entrapment efficiency,  Transmission Electron Microscopy. After that, the NLC gel was examined for Spreadability, Extrudabilty, Viscosity, In vitro drug release, Ex vivo permeation, Skin deposition and In vivo studies.

Results: The formulated Apremilast loaded showed particle size of less than 200 nm (i.e.170.32nm) with a narrow PDI of 0.267. Entrapment efficiency revealed that 89.26±01.22% of the drug was entrapped. Transmission electron microscopy images confirmed the spherical nature of the nanocarrier. The extended-release pattern of the formulated NLC for 24h was observed in the in vitro release studies and followed the Higuchi model(R2=0.9966). Ex vivo permeability showed a 6.14 fold increase in permeability and 74.05±0.25% deposition of apremilast loaded NLC gel compared to apremilast gel. The formulation was stable for three months without significant changes. In vivo skin studies showed that the prepared NLC did not have any skin irritation potential. The antipsoriatic activity demonstrated by the Apremilast loaded NLC gel in the imiquimod induced psoriasis model in mice was comparable to the standard treatment.

Conclusion: Apremilast loaded NLC demonstrated enhanced permeation, improved skin retention and extended-release compared to conventional gel. The developed formulation can be an alternative for psoriasis therapy after clinical trials in the future.
Postoperative Complications of Conventional Polypectomy Versus Endoscopic Sinus Surgery
Authors: Shaikh Arsalan Ahmed , Mahesar Mona Liza , Ahmed Noman , Yousuf Sajjad , Lakhiar Akhtar Ali , Shaikh Farhan Ahmed
Published: May 2021

Objective: To compare the postoperative complications of conventional polypectomy versus Endoscopic sinus surgery.

Study Design: This is cross sectional study.

Setting: Study carried out at E.N.T department, Tertiary care hospital from April 2019 - March 2020.

Materials & Methods:  52 out of which 32 were male and 20 were female. Benign nasal polyps within 14 yrs to 80 years from emergency and out- patient department both were included in our study. Only recurrent and neoplastic lesions were not inclusive of this study. Postoperatively the patient was prescribed with oral antibiotics, nasal decongestants and nasal douche with normal saline, followed by local steroids after 1.5 months. The post operative evaluation (both endoscopic and clinical) was done at 2 weeks, 6 weeks and 3 months post operatively and data was recorded. Statistical package for social sciences (SPSS) software version 20.0.

Results:  A total of 52 patients were recruited for the study with age ranging from 18 to 40 years.  The mean age was 24.65± SD 4.12. There were 32 (61.53%) males and 20 (38.46%) female patients. Two weeks were observed postoperative complications. The intranasal complications after simple intranasal polypectomy i.e. bleeding (SIP 8(30.76%) Versus ESS 5(19.23%)), crusting (SIP 10(38.46%) Versus ESS 6(23.07%)), Synechiae formation (SIP 3(11.53%) Versus ESS 1(3.84%)), recurrence 0% were observed. At upto 6th weeks observed the intranasal complications after simple intranasal polypectomy i.e. bleeding (SIP 5(19.23%) Versus ESS 2(7.69%)), crusting (SIP 6(23.07%) Versus ESS 2(7.69%)), Synechiae formation (SIP 2(7.69%) Versus ESS 1(3.84%)), recurrence 0% were observed. Three months were observed the intranasal complications after simple intranasal polypectomy i.e. bleeding (SIP 1(3.84%) Versus ESS 0%), crusting (SIP 0% Versus ESS 0%), Synechiae formation (SIP 4(15.38%) Versus ESS 3(11.53%)), recurrence 3(11.53%) were observed only in simple intranasal polypectomy group. While the intraorbital and intracranial complications were not observed. 

Conclusion: We would like to conclude our study in favor of ESS to be superior to other intranasal polypectomy procedures in terms of post operative complications.
Nitrate reductase activity in isolated heterocysts of the cyanobacterium Nostoc muscorum
Authors: Kumar A.P. , Rai A.N. , Singh H.N.
Published: July 2002

The nitrate reductase, nitrate reductase apoprotein and nitrate reductase Mo‐cofactor activities were measured in the cell‐free extracts of isolated heterocysts and whole filaments of the cyanobacteriumNostoc muscorum. The nitrate reductase activity of N2‐ and NO−
3‐grown whole filaments was 3.25 and 7.14 nmol NO−
2 formed·min−1·mg protein−1, respectively. No nitrate reducatase activity was found in the extracts of isolated heterocysts. However, when the heterocyst extract was supplemented with nitrate reductase apoprotein from the whole filaments, a reconstituted nitrate reductase activity of 6.4 nmol NO 2−
2 formed·min−1·mg protein−1 was detectable. Therefore, it was concluded that nitrate reductase in Nostoc muscorum was localized in the vegetative cells, that the heterocysts lacked nitrate reductase activity due to the lack of apoprotein, and that the Mo‐cofactor was present in heterocysts.
Preparation and amino acid sequence of human κ‐casein
Authors: Brignon Ghislaine , Chtourou Abdessatar , Ribadeau-Dumas Bruno
Published: July 2002

Human κ‐casein was prepared from whole casein by successive hydroxyapatite and thiol‐Sepharose chromatographies. The primary structure of its 99‐residue N‐terminal fragment has been determined by sequencing peptides obtained by tryptic and chymotryptic digestions of the whole protein. This fragment overlaps the known sequence of the 65‐residue C‐terminal fragment. The 158‐residue sequence of human κ‐casein was compared to those of goat, ewe, cow and rat κ‐caseins. Only 22% of the residues are identical in homologous positions. The rate of divergence of the 93‐residue N‐terminal segment (para‐κ‐casein) appears to be higher than that of the rest of the molecule.
Galactosylated poly(L‐lysine) as a hepatotropic carrier of 9‐β‐D‐arabinofuranosyladenine 5'‐monophosphate
Authors: Fiume L. , Bassi B. , Busi C. , Mattioli A. , Spinosa G. , Faulstich H.
Published: July 2002

D‐Galactopyranosyl residues were coupled to poly(L‐lysine) and the antiviral agents arabinofuranosyladenine 5'‐monophosphate (ara‐AMP) and acyclovir were conjugated with this glycosylated polymer. In mice the ara‐AMP conjugate accomplished a selective drug delivery to liver cells.
Cloning and complete amino acid sequences of human and murine basement membrane protein BM‐40 (SPARC, osteonectin)
Authors: Lankat-Buttgereit Brigitte , Mann Karlheinz , Deutzmann Rainer , Timpl Rupert , Krieg Thomas
Published: July 2002

Amino acid sequences of 285 and 286 residues, respectively, were deduced for mouse and human BM‐40 from cDNA clones isolated from expression libraries. The sequences showed 92% identity and were also essentially identical to those of bone osteonectin and of the parietal endoderm protein SPARC. About 60% of the mouse BM‐40 sequence was confirmed by Edman degradation. Two of the seven disulfide bonds were localized which apparently separate two distinct domains of mouse BM‐40.
The human lactase‐phlorizin hydrolase gene is located on chromosome 2
Authors: Kruse T.A. , Bolund L. , Grzeschik K.-H. , Ropers H.H. , Sjöström H. , Norén O. , Mantei N. , Semenza G.
Published: July 2002

The lactase‐phlorizin hydrolase gene was assigned to chromosome 2 by analysis of Southern blots of DNA from a panel of human‐rodent cell hybrids containing characteristic sets of human chromosomes. The hybridization probe used was a recently isolated cDNA clone of the human lactase‐phlorizin hydrolase gene.
Octopus rhodopsin Amino acid sequence deduced from cDNA
Authors: Ovchinnikov Yu.A. , Abdulaev N.G. , Zolotarev A.S. , Artamonov I.D. , Bespalov I.A. , Dergachev A.E. , Tsuda M.
Published: July 2002

The primary structure of rhodopsin from the octopus Paroctopus defleini has been determined by parallel analysis of the protein and corresponding cDNA. The amino acid sequence is most similar to the recently cloned Drosophila opsins. Similarities to bovine and human opsins are also evident. The transmembrane topology of octopus rhodopsin is discussed.
A physical characterization of some detergents of potential use for membrane protein crystallization
Authors: Timmins P.A. , Leonhard M. , Weltzien H.U. , Wacker T. , Welte W.
Published: July 2002

Micellar solutions of lauryldimethylamine oxide, n‐dodecyl‐β‐D‐maltoside and 1‐dodecanoylpropanediol‐3‐phosphorylcholine were studied by use of small‐angle neutron scattering. These detergents have been selected due to their use as solubilizing agents for membrane proteins. LDAO was found to form a homogeneous, approximately spherical micelle with a radius of 20.7 Å and an M
r of 16 000. N‐Dodecyl‐β‐D‐maltoside forms an inhomogeneous micelle with a core of low scattering density surrounded by a shell of high scattering density. The data are in accord with a micelle forming an oblate ellipsoid and the disaccharide group pointing outward radially from the hydrophobic group. The semi‐axes are 16.8 and 25.5 Å and the M
r is 66 000. 1‐Dodecanoylpropanediol‐3‐phosphorylcholine forms a rather homogeneous, roughly spherical micelle. The radius is 24 Å, the M
r being 28 700. The data indicate a tangential packing of the phosphorylcholine head groups into a polar layer of 3–4 Å surrounding the micelle core. The use of these detergents as solubilizing agents during membrane protein crystallization is discussed.
Purification and characterization of a lipocortin‐like 33 kDa protein from guinea pig neutrophils
Authors: Sato Eisuke F. , Miyahara Masanobu , Utsumi Kozo
Published: July 2002

A lipocortin‐like, phospholipase A2 inhibitory 33 kDa protein was purified from guinea pig neutrophils. From amino acid composition and sequence data, this protein was found to have a high degree of homology to human lipocortin I. This protein inhibited porcine pancreatic phospholipase A2 activity in the presence of [3H]oleic acid‐labeled Escherichia coli membranes as substrate. Maximal inhibition amounted to 65% whereas 50% inhibition occurred at 83.5 nM. This protein showed F‐actin‐binding ability in a Ca2+‐dependent manner.
Production of carrier proteins for insulin‐like growth factors (IGFs) by rat osteoblastic cells Regulation by IGF I and cortisol
Authors: Schmid C. , Zapf J. , Froesch E.R.
Published: July 2002

A bone‐derived rat cell line, PyMS, releases IGF I and IGF carrier proteins which are similar to those found in rat serum. Western blot analysis of culture media conditioned by hormone‐treated cells shows that growth hormone and IGF I stimulate and cortisol inhibits production of IGF carrier proteins in vitro. A glycosylated carrier protein species of 49‐42 kDa is closely related to the subunits of the growth hormone‐dependent carrier protein complex found in rat serum. In addition, rhIGF I rapidly induces a 32 kDa, non‐glycosylated IGF‐binding protein whose accumulation is markedly increased by cortisol.
Probing the primary quinone environment in photosynthetic bacterial reaction centers by light‐induced FTIR difference spectroscopy
Authors: Breton J. , Thibodeau D.L. , Berthomieu C. , Mäntele W. , Vermèglio A. , Nebedryk E.
Published: July 2002

The Photoreduction of the primary electron acceptor, QA, has been characterized by light‐induced Fourier transform infrared difference spectroscopy for Rb. spaeroides reaction centers und for Rsp. rubrum and Rp. viridis chromatophores. The samples were treated both with redox compounds, which rapidly reduce the photooxidized primary electron donor P+, and with inhibitors of electron transfer from QA
− to the secondary quinone QB. This approach yields spectra free from P and P+ contributions which makes possible the study of the microenvironment of QA and QA
−.
Slow electrogenic events in the cytochrome bc1‐complex of Rhodobacter sphaeroides The electron transfer between cytochrome b hemes can be non‐electrogenic
Authors: Mulkidjanian Armen Ya. , Mamedov Mahir D. , Drachev Lel A.
Published: July 2002

The flash‐induced formation of transmembrane electric potential differences (measured by carotenoid bandshift) and redox changes of cytochrome bh
(b
561) were monitored spectrophotometrically in Rb. sphaeroides chromatophores in a pH range from 7.5 to 10.0. It is shown that in the presence of antimycin A and at pH < 8.3 the myxothiazol‐sensitive, antimycin‐insensitive component of the carotenoid bandshift is kinetically coupled to cytochrome bh
reduction. The kinetics of both processes can be described by a single exponent with a rise time of about 10 ms. Alkalization of the medium (8.3 ≤ pH ≤ 9.2) causes the appearance of an additional constituent in this phase of the carotenoid response with the rise time varying in the range of 100–300 ms. With a further pH increase (pH > 9.2), the electrogenic constituent, kinetically linked to cytochrome bh
reduction, diminishes. The obtained data are discussed within the framework of the scheme, assuming that the electron transfer between bl
and bh
hemes in the bc
1 complex is, under certain conditions, accompanied by proton transfer in the same direction.
Respiratory burst inhibition in human neutrophils by ultra‐low doses of [D‐Ala2]methionine enkephalinamide
Authors: Zaitsev S.V. , Sazanov L.A. , Koshkin A.A. , Sud'ina G.F. , Varfolomeev S.D.
Published: July 2002

An ultra‐low dose (10−14 M) of opioid peptide [D‐Ala2]methionine enkephalinamide (DAMEA) is found to exert an inhibitory effect on the production of reactive oxygen species (respiratory burst) in human neutrophils. The validity of this phenomenon has been verified in a series of studies that comprised 30 experiments. The inhibition has proved to be statistically significant (P<0.001). The dose‐response dependence of the effect (10−15−10−9 M) followed a characteristic biphasic pattern (with the maximum effect at ultra‐low doses). An opioid antagonist, naloxone partially blocks the inhibitory effect, which indicates that the DAMEA action is at least partially mediated by opioid receptors.
Molecular cloning of the cDNAs coding for the two subunits of soluble guanylyl cyclase from human brain
Authors: Giuili Galicia , Scholl Ute , Bulle Frédérique , Guellaën Georges
Published: July 2002

Complementary DNA clones corresponding to the 70 and 82 kDa subunits of soluble guanylyl cyclase from human adult brain have been isolated and sequenced. Their respective open reading frames correspond to 619 amino acids (M
r 70,469) and 717 amino acids (M
r 81,324). Southern blots of human genomic DNA using these clones as probes give patterns which might be compatible with the presence of more than one copy per gene, or pseudogenes, for each subunit in the human genome, Comparison of the protein sequence of the large subunit from adult brain with the subunit cloned from human fetal brain (Harteneck, C., Wedel, B., Koesling, D., Malekewitz, J., Böhme, E. and Schultz, G. (1991) FEBS Lett. 292, 217–222) revealed only 34% homology. This result demonstrates the existence of a novel large subunit isoform for soluble guanylyl cyclase in human tissues.
Thermal transitions in the purple membrane from Halobacterium halobium
Authors: Shnyrov Valery L. , Mateo Pedro L.
Published: July 2002

The application of a successive annealing procedure to the scanning calorimetric endotherm of the purple membrane from Halobacterium halobium in phosphate buffer, pH 7.5, leads to five thermal transitions beneath the overall endotherm. Circular dichroism and fluorescence experiments have also been carried out with the native membrane heated at the same scan rate as in calorimetric runs (1°C/min) as well as with previously heated membrane samples. These results, together with others from the literature, have been used to suggest a preliminary explanation of the five thermal transitions.
Pregnancy associated increase in mRNA for soluble D‐factor/LIF receptor in mouse liver
Authors: Tomida Mikio , Yamamoto-Yamaguchi Yuri , Hozumi Motoo
Published: July 2002

We examined the distribution of mRNAs for differentiation‐stimulating factor (D‐factor)/leukemia inhibitory factor (LIF) receptor in various mouse tissues by Northern blotting. A mouse cDNA fragment encoding the D‐factor receptor was prepared by the RT‐PCR method using human cDNA sequences as primers. The smallest mRNA (3 kb) was present in the liver, but not detectable in other tissues examined. Larger mRNAs (5 and 10 kb) were present in the placenta and the M1 cells, and also detectable in the liver, kidney, heart, lung, brain and embryos. Expression of 3 kb mRNA in the liver increased during pregnancy, being 20 times the initial level on day 15. D‐factor receptor cDNAs were isolated from a cDNA library prepared from the liver of a pregnant mouse. Most of the cDNA clones encoded a soluble receptor. A cDNA probe specific for the cellular receptor did not hybridize with 3 kb mRNA in the liver. These results suggest that 3 kb mRNA encodes a soluble D‐factor receptor and that the liver is the primary site of synthesis of this soluble receptor.
The changes of prooxidant and antioxidant enzyme activities in bovine leukemia virus‐transformed cells Their influence on quinone cytotoxicity
Authors: Nemeikait≐ Ausra , C̆≐nas Narimantas
Published: July 2002

It was found that the activities of prooxidant enzymes (NAD(P)H oxidases and NAD(P)H:cytochrome c reductases) in bovine leukemia virus‐transformed calf and lamb embryo kidney fibroblasts (lines Mi‐18 and FLK) were by 1.25–18 times higher when compared to corresponding nontransformed calf cells. The activity of DT‐diaphorase was also increased by about one order of magnitude in transformed cells. The activities of antioxidant enzymes were almost unchanged (superoxide dismutase), decreased by 13% or 53% (catalase) or increased by 25% or 90% (glutathione reductase) in Mi‐18 or FLK cells, respectively. These changes of enzyme activity increased the toxicity of simple redox‐cycling quinones (duroquinone, naphthazarin) towards transformed cells, but did not affect the toxicity of daunorubicin. The latter was most probably related to the inhibition of plasma membrane NADH dehydrogenase.
Efficient product clearance through exit channels in substrate hydrolysis by acetylcholinesterase
Authors: Kovach Ildiko M. , Qian Naifeng , Bencsura Akos
Published: July 2002

The channels connecting the active site of acetylcholinesterase (AChE) to the protein exterior were mapped by computational techniques in order to find potential exit routes for charged reaction products. 3.9% of the total volume of the AChE monomer is hollow space and over 50% of the void is located in the center; it is partitioned into three chambers, a deep entry channel, below it a wide channel located in a slightly positive region of AChE and ideally suitable for the exit of negatively charged fragments and a small chamber above Trp84 and Met83. The latter serve as gates for the departure of the positively charged choline product of the hydrolysis of acetylcholine into the small cavity. An efficient product clearance is a prerequisite to a very low energy pathway for the irreversible hydrolysis of acetylcholine.
A general method for the preparation of mixed micelles of hydrophobic peptides and sodium dodecyl sulphate
Authors: Killian J.Antoinette , Trouard Theodore P. , Greathouse Denise V. , Chupin Vladimir , Lindblom Göran
Published: July 2002

A new method is reported for the incorporation of hydrophobic peptides into sodium dodecyl sulphate (SDS) micelles. First, a homogeneous solution of peptide and detergent is obtained by adding the peptide in trifluoroethanol to an equal volume of an aqueous solution of SDS. Upon subsequent addition of excess water, mixed peptide‐SDS micelles are formed. Next, all solvent is removed by lyophilization and an appropriate amount of water is added to the dry powder. For various hydrophobic peptides this was shown to yield clear and stable solutions that are highly concentrated and suitable for characterization by spectroscopic techniques.
Autoimmunity in Stiff‐Man Syndrome with breast cancer is targeted to the C‐terminal region of human amphiphysin, a protein similar to the yeast proteins, Rvs167 and Rvs161
Authors: David Carol , Solimena Michele , De Camilli Pietro
Published: July 2002

Amphiphysin, a neuronal protein first identified in chicken synaptic membranes, is the autoantigen of Stiff‐Man Syndrome (SMS) associated with breast cancer. We have now cloned human amphiphysin and found the N‐ and C‐terminal domains of the protein to be highly conserved between chicken and human. Patient autoantibodies have a distinct pattern of reactivity with amphiphysin, and the dominant autoepitope is located in its C‐terminal region, which contains an SH3 domain. Portions of chicken and human amphiphysin are also homologous to portions of Rvs167 and Rvs161, two yeast proteins which are involved in cell entry into stationary phase upon exposure to unfavourable growth conditions.
NMR solution structure of the recombinant tick anticoagulant protein (rTAP), a factor Xa inhibitor from the tick Ornithodoros moubata
Authors: Antuch W. , Güntert P. , Billeter M. , Hawthorne T. , Grossenbacher H. , Wüthrich K.
Published: July 2002

The solution structure of the recombinant tick anticoagulant protein (rTAP) was determined by 1H nuclear magnetic resonance (NMR) spectroscopy in aqueous solution at pH 3.6 and 36°C. rTAP is a 60‐residue protein functioning as a highly specific inhibitor of the coagulation protease factor Xa, which was originally isolated from the tick Ornithodoros moubata. Its regular secondary structure consists of a two‐stranded antiparallel β‐sheet with residues 22–28 and 32–38, and an α‐helix with residues 51–60. The relative orientation of these regular secondary structure elements has nearly identical counterparts in the bovine pancreatic trypsin inhibitor (BPTI). In contrast, the loop between the β‐sheet and the C‐terminal α‐helix as well as the N‐terminal 20‐residue segment preceding the β‐sheet adopt different three‐dimensional folds in the two proteins. These observations are discussed with regard to the implication of different mechanisms of protease inhibition by rTAP and by Kunitz‐type protein proteinase inhibitors.
Phosducin inhibits receptor phosphorylation by the β‐adrenergic receptor kinase in a PKA‐regulated manner
Authors: Hekman Mirko , Bauer Petra H. , Söhlemann Peter , Lohse Martin J.
Published: July 2002

Homologous or receptor‐specific desensitization of β‐adrenergic receptors is thought to be triggered by receptor phosphorylation mediated by the β‐adrenergic receptor kinases (ßARK). Upon receptor activation, cytosolic ßARK translocates to the membrane, probably by binding to G‐protein βγ‐subunits. Using the purified proteins reconstituted into phospholipid vesicles we show here that this binding process can be inhibited by phosducin, a cytosolic protein that has recently been described as a regulator of G‐protein‐mediated signalling. Phosducin appears to complete very effectively with ßARK for the G‐protein βγ‐subunits. These inhibitory effects of phosducin on receptor phosphorylation are antagonized following phosphorylation of phosducin by protein kinase A. It is proposed that phosducin may act as a regulator of homologous β‐adrenergic receptor desensitization.
Yeast cells with a specific cellular make‐up and an environment that removes acetaldehyde are prone to sustained glycolytic oscillations
Authors: Richard Peter , Diderich Jasper A. , Bakker Barbara M. , Teusink Bas , van Dam Karel , Westerhoff Hans V.
Published: July 2002

Glycolytic oscillations can be induced by adding glucose to starved Saccharomyces cerevisiae cells and, after a steady state has been established, cyanide. Transient oscillations or limit‐cycle oscillations can be induced depending on the growth phase in which the cells are harvested. To find what causes these differences in the dynamic behaviour, we analyzed glycolytic enzyme activities at different growth phases. The hexokinase activity increased by a factor of three after growth substrate transition from glucose to ethanol; the other measured activities remained constant. Cyanide was found not only to block respiration, but also to trap acetaldehyde. Both cyanide actions appear necessary for the occurrence of sustained glycolytic oscillations.
Aggregated DNA in ethanol solution
Authors: Piškur Jure , Rupprecht Allan
Published: July 2002

A recently developed mechanochemical method has provided a new, efficient tool for studies on the thermal stability and structure of aggregated DNA in ethanol‐water solutions. At low ethanol concentrations DNA is fully soluble and is in the B form. However, with increasing ethanol concentration the melting temperature of DNA, T
m, decreases. At a critical ethanol concentration dependent on the nature and concentration of the counterion, aggregation of the DNA molecules sets in. This is reflected in a marked increase in T
m indicating that the aggregated DNA molecules are thermally more stable than the dissolved ones. However, they are still in the B form. In general, T
m of aggregated DNA also decreases with further increasing ethanol concentration and is dependent on the nature of the counterion, but T
m is not affected by the concentration of the counterion (excess salt) in the ethanol‐water solution. When the ethanol concentration reaches the range of 70–80% (v/v), the B‐to‐A conformational transition occurs in the case of Na‐, K‐ and CsDNA. Above this transition point the A form is more stable than the B form due to the reduced water activity and to increased interhelical interactions. At very high ethanol concentrations, above 85% and dependent on the nature of the counterion, a drastic change in the thermal behaviour is observed. Apparently such a strong interhelical interaction is induced in the aggregated DNA that the DNA is stabilized and cannot adopt a random coil state even at very high temperatures. This stability of DNA in the P form is fully reversed if the ethanol concentration is lowered and the activity of water, thereby, is restored.
Evidence for bidirectional histamine transport by murine hematopoietic progenitor cells
Authors: Corbel Stéphane , Dy Michel
Published: July 2002

Murine hematopoietic progenitor cells synthesize substantial amounts of histamine in response to IL‐3 or calcium ionophore. They also take up extracellular histamine by an active transport system. In the present study we demonstrate that this system mediates both influx and efflux of histamine. Indeed, MR16155 and thioperamide, the two H3 antagonists which are most effective in inhibiting histamine uptake, likewise diminish the release of preloaded histamine from bone marrow cells. These compounds also inhibit the release of histamine which has been newly synthesized by hematopoietic progenitors in response to IL‐3 or calcium ionophore, as assessed by the accumulation of the mediator inside the cells in the presence of the antagonists. The potency of different histamine receptor antagonists as inhibitors of histamine release increases with their capacity to block histamine uptake.
Semantic inhibition disorders in schizophrenic patients assessed by a lexical decision task
Authors: Passerieux C , Hardy-Bayle MC , Widlöcher D
Published: July 2002

Lexical decision tasks were used in 17 schizophrenic subjects and 11 control subjects, to evaluate the so-called automatic priming of semantic links, and the controlled processes which involve longer lexical anticipation strategies. In this type of trial, inhibition in the recognition of the target word, when the preceding priming word is not semantically linked to it, indicates the activation of such controlled processes. Postulating that patients in the schizophrenic group were heterogeneous in terms of cognition, we compared the resultant scores in two subtypes of schizophrenic patients: paranoid and hebephrenic (CIM-9 criteria). The study demonstrated that there was a difference in performance between the schizophrenic subtypes. Although these findings need to be confirmed, they demonstrate the necessity of determining individual profiles of patients entering the trial, to take into account those of their phenomenological differences that may correspond to differences in cognitive functioning. The results indicate an absence of inhibition, but only in the paranoid group. In these subjects, results were consistent with the hypothesis of a failure to set up controlled processes rather than a stronger “automatic” activation of the semantic links. However, as the results were not significant, the hypothesis remains open to further investigation. The reasons for the nonsignificance of the results and alternative hypotheses are discussed.