bluuebunny/crossref_metadata_2025 huggingface dataset:
Knowledge of Chakma Women on Shifting Cultivation: A Comparative Study between Bangladesh and India
Authors: Bhattacharjee D. , Barau A. A. , Haque M. E. , Haque M. E. , Afrad M. S. I.
Published: April 2020

Shifting cultivation is the primary livelihood of the Chakma people where women participation is visibly prominent. Hence, this study comparatively examined the knowledge of Chakma women participating in shifting cultivation in Bangladesh and India. Three hundred respondents were selected following stratified disproportionate random sampling. Data were collected using interview schedule and analyzed through descriptive statistics. Majority of respondents were middle age, illiterate, had medium-sized families with small sized farms and an annual income below their expenditure. Most of them have good knowledge on primitive shifting cultivation, but possessed poor knowledge on modern agricultural practices like IPM/ICM and balanced use of fertilizer. Fruit gardening, banana and turmeric cultivation were the key promising alternatives in Bangladesh, but in India; rubber plantation, fruit gardening, turmeric cultivation and lemon plantation were the main alternatives to shifting cultivation. Land scarcity, rodent attack, insect infestation and disease outbreak were the major problems in shifting cultivation in Bangladesh, whereas low price of products, lack of irrigation facility and land scarcity were the major problems in shifting cultivation in India. Thus, awareness campaigns on scientific use of land and need based skill training addressing gender issues may be designed for alternative livelihood promotion in both the countries.
Haematological Studies of Clarias gariepinus Exposed to Ethanolic Stem Bark Extracts of Ackee, Blighia sapida
Authors: Effiong M. U. , Sunday E. A. , Ella F. A.
Published: April 2020

The study evaluated effects of sub-lethal concentrations (0.00, 1.6, 3.2, 6.4, 12.8 g/l) of ethanolic stem bark extracts of ackee, Blighia sapida on haematological profile of Clarias gariepinus (mean weight, 6.95± 1.02 g; total length 11.7±1.32 cm). Each concentration was treated in triplicate using a static bioassay system. The exposure period was 21 days. Physico-chemical parameters of water were monitored throughout the study period. Results revealed that haematocrit, red blood cell, haemoglobin and mean corpuscular haemoglobin concentration counts were significantly (p<0.05) depleted with increase in extract concentration while white blood cell counts increased (p<0.05) linearly from 198.2, 198.5, 208.8, 219.4 and 241.53 x 103 cells/µl in 0.00, 1.6, 3.2, 6.4 and 12.8 g/l respectively. The levels of water temperature increased with extract concentrations while dissolved oxygen and pH contents decreased. The implications of these results showed that stem bark extract of ackee had negative effects on the blood of treated fish. This may further explain the decline in wild fishery resources in the locality where the plant parts were collected. In view of this, the direct use of this plant in harvesting fish by local fisher folks in Southern Nigeria should be discouraged until information that aid its application in a sustainable manner is made available through further studies.
Evaluation of Two Kurdistan-Iraq Crude Oil (T-21A, PF2) by Derivatographic Method
Authors: Simo Sherwan Mohammad , Naman Salah Aldin , Ahmed Kanaan Ramadan , Faritovich Akhmetov Arslan
Published: April 2020

Evaluation of crude oil and its residue using derivatography, is one of the most common physical and chemical methods analytical research. Crude oil residues 350+ obtain from two Iraq-Kurdistan crudes (Tawke T-21A well and Shekhan PF2 well) by using atmospheric distillation after removing all volatile fractions. The sample characterized by direvatographic method. The thermo analysis, reactions were carried out at temperature range 20- 700℃ for reaction time 68 min. These derivatograph curves show the weight change and heat energy (Enthalpy) change as the function of time and temperature. It shows that the crude oil residues have different composition. The curve which marks the weight changes of the sample heated is the thermogravimetric curve, TGA. Whereas the curve, which records heat energy or enthalpy changes during thermal decomposition is the DTA or differential thermoanalytic. By means of the derivatograph, it is possible to record simultaneously curve of weight change (TG), and enthalpy change (DTA) as a function of temperature. This method analysis shows good evaluation of these two crude oil well.
Hyperbaric Oxygen Therapy Ameliorates the Harmful Effects of Dexamethasone Induced Diabetes on Liver and Pancreas of Adult Male Albino Rats
Authors: El-Helbawy Nehal Farid , Abd Al-Salam Alhaz Abd Al-Hai , El-Sawaf Manal El-Sayed , El-Deeb Safwat Abd El-Aziz
Published: April 2020

Aims: This study was done to clarify the effects of hyperbaric oxygen therapy on the harmful changes of liver and pancreas of adult male albino rats after dexamethasone induced diabetes.

Place of Study: Faculty of medicine, Tanta University, Egypt.

Methodology: Thirty two adult male albino rats were divided into; group I (control), group II (Hyperbaric oxygen treated), Group III (induced diabetes - non treated group) and Group IV (induced diabetes + Hyperbaric oxygen treated group). Induction of diabetes was done by dexamethasone injection for ten days. Hyperbaric oxygen was given once per day for 5 sessions in group II and IV. The rats of all groups were sacrificed after the 20th day. Specimens of liver and pancreas were subjected to microscopic examination.

Results: Rats from group III showed a highly significant increase of blood glucose compared to the controls. Treated rats in group IV showed highly significant decrease in blood glucose compared to group III. Hepatic steatosis and histopathological changes of pancreatic acini and islets of Langerhans were noticed in untreated diabetic rats. Group IV after Hyperbaric oxygen therapy revealed partial improvement of histological and ultrastructural effects of diabetes on the liver and pancreas.

Conclusions: HBOT is partially effective in reducing blood glucose level and improving the hazardous effect of untreated diabetes on the histological and ultrastructural architecture of the liver and pancreas of male albino rats.
Comparative Studies on Dimensional, Gravimetric and Frictional Properties of Chhattisgarh Popular Paddy Varieties for Suitability of Flaked Rice (Paha)
Authors: Dahare Rahul , Nishad Tankesh Kumar , Sahu Bhupendra
Published: April 2020

The present study on different characteristics of some selected varieties of paddy was undertaken to study dimensional, gravimetric and frictional properties of paddy. The physical properties such as average length, width, thickness, geometric mean diameter, aspect ratio, sphericity, volume, surface area, L/B ratio, true density, bulk density, porosity, angle of repose and coefficient of friction on different surfaces of paddy varieties were measured to have an initial information of the input. All varieties have different dimensional properties, for the length of Rajeshwari, Durgeshwari and Mahamaya paddy variety 9.21 to 9.34 mm, for width 2.41 to 2.79 mm and for thickness 1.83 to 2.45 mm respectively. The geometric mean diameter and aspect ratio for Rajeshwari, Durgeshwari and Mahamaya paddy variety was observed 3.43 to 4.08 mm and 25.21 to 30.13% respectively. True density and bulk density of Rajeshwari, Durgeshwari and Mahamaya paddy variety were observed 1056.86 to 1350.43 kg/m3 and 580.18 to 695.77 kg/m3 respectively. The angle of repose of Rajeshwari, Durgeshwari and Mahamaya paddy variety was observed 42.23° to 48.51°.
A role for glycosaminoglycans in the development of collagen fibrils
Authors: Parry David A.D. , Flint Michael H. , Gillard Gerald C. , Craig Alan S.
Published: July 2002

Extensive data on the glycosaminoglycan (GAG) composition and the collagen fibril diameter distribution have been collected for a diverse range of connective tissues. It is shown that tissues with the smallest diameter collagen fibrils (mass‐average diameter < 60 nm) have high concentrations of hyaluronic acid and that tissues with the largest diameter collagen fibrils (mass‐average diameter ∼200 nm) have high concentrations of dermatan sulphate. It is suggested that the lateral growth of fibrils beyond a diameter of about 60 nm is inhibited by the presence of an excess of hyaluronic acid but that this inhibitory effect may be removed by an increasing concentration of chondroitin sulphate and/or dermatan sulphate. It is also postulated that high concentrations of chondroitin sulphate will inhibit fibril growth beyond a mass‐average diameter of ∼150 nm. Such an inhibition may in turn be removed by an increasing concentration of dermatan sulphate such that it becomes the dominant GAG present in the tissue.
Assignment of the human tyrosine hydroxylase gene to chromosome 11
Authors: Powell John F. , Boni Claudette , Lamouroux Annie , Craig Ian W. , Mallet Jacques
Published: July 2002

Using a panel of human‐mouse somatic cell hydrids and a cDNA probe for human tyrosine hydroxylase, we have assigned the structural gene for tyrosine hydroxylase to chromosome 11 by Southern blotting techniques.
Elucidation of cathepsin B‐like activity associated with extracts of human myelin basic protein
Authors: Berlet Hans H. , Ilzenhöfer H.
Published: July 2002

Myelin basic protein (MBP) extracted from human delipidated white matter was found to be degraded at pH 3.0 by endogenous proteolytic activities of extracts. Electrophoretic peptide patterns were consistent with limited proteolysis of MBP. Based on pH, activation by EDTA and DTE, and inhibition by p‐CMPS, E‐64 and, in particular, by leupeptin, the protease involved was tentatively identified as cathepsin B or a cathepsin B‐like enzyme. As pepstatin failed to inhibit acid proteolysis of MBP cathepsin D was ruled out.
A major role for protein kinase C in calcium‐activated exocytosis in permeabilised adrenal chromaffin cells
Authors: Burgoyne Robert D. , Morgan Alan , O'Sullivan Antony J.
Published: July 2002

The role of endogenously activated protein kinase C in calcium‐activated exocytosis was examined in digitonin‐permeabilised bovine adrenal chromaffin cells. Protein kinase C activity was reduced by down‐regulation following long‐term treatment with PMA or by using the inhibitor sphingosine. Both treatments resulted in a substantial reduction in catecholamine secretion elicited by micromolar calcium, indicating that endogenous activation of protein kinase C is a major requirement for calcium‐activated exocytosis in chromaffin cells.
Shift in rat liver glycolysis control from fed to starved conditions Flux control coefficients of glucokinase and phosphofructokinase
Authors: Torres Néstor V. , Mateo Fátima , Meléndez-Hevia Enrique
Published: July 2002

The distribution of flux control coefficients of a glycolytic system in starved rat liver has been determined. The flux control coefficient profile in starved conditions is compared with normal fed conditions showing that in the former phosphofructokinase enhances more than 2‐fold its flux control coefficient while glucokinase decreases slightly. The results also show that the starved system has a more complex structure probably because of the greater influence on the flux of the reverse substrate cycles and the synthesis and degradation fructose 2,6‐bisphosphate reactions.
Cloning and expression of a novel rat GABAA receptor
Authors: Lolait Stephen J. , O'Carroll Anne-Marie , Kusano Kiyoshi , Muller Jean-Marc , Brownstein Michael J. , Mahan Lawrence C.
Published: July 2002

Two full‐length cDNA clones encoding α‐ and β‐subunits of a GABAA receptor have been isolated from a rat cerebral cortex cDNA library. The mature α‐subunit protein consists of 428 amino acids with a calculated M
r of 48680. This protein is highly homologous (∼99% amino acid identity) with the bovine brain α1‐subunit receptor [(1988) Nature 335, 76–79]. The mature rat β‐subunit receptor is a 448 amino acid polypeptide and shares ∼ 80% amino acid identity with the previously characterized bovine GABAA receptor β‐subunit [(1987) Nature 328, 221–227]. Co‐expression of the cloned DNA in Xenopus oocytes produces a functional receptor and ion channel with pharmacological characteristics of a GABAA receptor. GABAA α‐ and β‐subunit mRNA is detectable in the cortex, cerebellum and hippocampus.
Molecular cloning and sequencing of human cDNA for phosphoribosyl pyrophosphate synthetase subunit II
Authors: Iizasa Taizo , Taira Masanori , Shimada Hideaki , Ishijima Sumio , Tatibana Masamiti
Published: July 2002

cDNA clones for human phosphoribosyl pyrophosphate synthetase subunit II (PRS II) were isolated. The five overlapping clones contained 2457 base pairs (bp) covering a 954‐bp complete coding region for 318 amino acid residues. Homologies between human and rats PRS II were 99% of the amino acid and 88% of the nucleotides in the coding region. This amino acid homology seems to be the highest so far reported for enzymes involved in nucleotide metabolism and glycolysis. The highly conserved structure may be required for unique catalysis and rigid regulation of this enzyme.
Antibacterial and antimalarial properties of peptides that are cecropin‐melittin hybrids
Authors: Boman H.G. , Wade D. , Boman I.A. , Wåhlin B. , Merrifield R.B.
Published: July 2002

Solid phase synthesis was used to produce 5 hybrid peptides containing sequences from the antibacterial peptide, cecropin A, and from the bee venom toxin, melittin. Four of these chimeric peptides showed good antibacterial activity against representative Gram‐negative and Gram‐positive bacterial species. The best hybrid, cecropin A(1–13)‐melittin(1–13) was 100‐fold more active than cecropin A against Staphylococcus aureus. It was also a 10‐fold better antimalarial agent than cecropin B or magainin 2. Sheep red cells were lysed by melittin at low concentrations, but not by the hybrid molecules, even at 50 times higher concentrations.
Evidence for two independent pathways in the stimulation of steroidogenesis by luteinizing hormone involving chloride channels and cyclic AMP
Authors: Choi Michael S.K. , A. Cooke Brian
Published: July 2002

The possible role of chloride channels in luteinizing hormone (LH) action on steroidogenesis in rat Leydig cells had been investigated. A chloride channel blocker, SITS (4‐acetamido‐4'‐isothiocyanatostilbene‐2,2'‐disulphonic acid), inhibited LH‐stimulated steroidogenesis at low (⩽ 1 ), but not at high (100 ) LH concentrations. In addition, dibutyryl cyclic AMP‐ and forskolin‐stimulated steroidogenesis was unaffected by SITS. The removal of extracellular chloride potentiated steroidogenesis stimulated by submaximal but not maximal doses of LH. These results suggest that at low levels of LH, steroidogenesis depends on chloride channels whereas with high levels, cyclic AMP is the mediator of LH action.
Analysis of PI (phosphatidylinositol)‐anchoring antigens in a patient of paroxysmal nocturnal hemoglobinuria (PNH) reveals deficiency of 1F5 antigen (CD59), a new complement‐regulatory factor
Authors: Taguchi Ryo , Funahashi Yasuhiro , Ikezawa Hiroh , Nakashima Izumi
Published: July 2002

FACS analysis together with PIPLC treatment was applied to Pi‐anchoring antigens such as DAF (decay‐accerelating factor, CD55), 1F5 antigen (CD59), CD14 and CD16 on the cell surfaces of blood cells from a normal adult and a male patient with paroxysmal nocturnal hemoglubinuria (PNH). Through the extensive analysis, this patient proved to be completely defective in 1F5 antigen, a newly found complement‐regulatory protein, on all the blood cells tested. In normal blood cells such as lymphocytes, monocytes and granulocytes, 1F5 antigen was expressed as one of PI‐anchoring proteins. In contrast to most of PNH patients, this patient reserved DAF, CD14 and CD16 at normal levels in his erythrocytes, monocytes and granulocytes. Also, there were no significant differences between the normal adult and the patient in the activities of erythrocyte acetylchol‐inesterase and granulocyte alkaline phosphatase which were also known to be PI‐anchoring enzymes. Thus, deficiency of 1F5 antigen must be deeply related to the clinical symptoms of PNH in this patient.
Rates of cholesterol, ubiquinone, dolichol and dolichyl‐P biosynthesis in rat brain slices
Authors: Andersson M. , Elmberger P.O. , Edlund C. , Kristensson K. , Dallner G.
Published: July 2002

Slices from the brain and liver of rats were prepared and upon incubation exhibited a continuous and high capacity for incorporation of radioactive precursors into proteins and lipids. Using [3H]mevalonate as precursor, the rates of biosynthesis of cholesterol, ubiquinone, dolichol and dolichyl‐P in brain slices were determined and found to be 5.5,0.25,0.0093 and 0.0091 nmol/h/g, respectively. Dolichol and dolichyl‐P accumulate to a limited extent, but almost all of these lipids in the brain originate from de novo synthesis. The calculated half‐lives for cholesterol, ubiquinone, dolichol and dolichyl‐P were 4076, 90, 1006 and 171 h, respectively. The results indicate that lipids formed via the mevalonate pathway in the brain have an active and independently regulated biosynthesis.
The control of interferon‐inducible gene expression
Authors: Kerr Ian M. , Stark George R.
Published: July 2002

The αβ interferons (IFNs) transiently induce genes through an IFN‐stimulable DNA response element (ISRE). IFN‐cell surface receptor interaction triggers the cytoplasmic activation of the complex primary transcription factor E, which on translocation and interaction with the ISRE initiates transcription. Whether E is activated directly through the receptor(s) or through a more classical second message pathway(s) and the roles of additional factors in the αβ and γ IFN responses remain to be established. Meanwhile analysis of mutants has revealed complexity and overlap in the α,β and γ IFN response pathways and the products of at least two viruses have been shown to inhibit IFN‐inducible gene expression.
Paraoxonase prevents accumulation of lipoperoxides in low‐density lipoprotein
Authors: Mackness Michael I. , Arrol Sharon , Durrington Paul N.
Published: July 2002

Oxidative modification of low‐density lipoprotein (LDL) enhances its uptake by macrophages in tissue culture and in vivo may underly the formation of arterial fatty streaks, the progenitors of atheroma. We investigated the possible protection which high‐density lipoprotein (HDL) affords against LDL oxidation. The formation of lipoperoxides and thiobarbituric acid reactive substances when LDL was incubated with copper ions was significantly decreased by HDL. The enzyme, paraoxonase (E.C. 3.1.8.1), purified from human HDL, had a similar effect and thus may be the component of HDL responsible for decreasing the accumulation of lipid peroxidation products.
Mechanical influence and cAMP injection evoke the same reaction of neuron ionic channels
Authors: Minina Svetlana V. , Myakotina Olga L. , Avdonin Vladimir B. , Liberman Efim A.
Published: July 2002

Intracellular cAMP injection and negative pressure in the patch‐electrode increase the interburst closed time of the same potassium ionic channels in the snail neuron membrane. Sodium channels which were registered as change of background noise are activated both by cAMP injection and by negative pressure. These results are considered in connection with data about the unusual biochemistry of the neuron reaction to cAMP.
Growth‐promoting activity of tissue inhibitor of metalloproteinases‐1 (TIMP‐1) for a wide range of cells A possible new growth factor in serum
Authors: Hayakawa Taro , Yamashita Kyoko , Tanzawa Kazuhiko , Uchijima Ekuko , Iwata Kazushi
Published: July 2002

Human tissue inhibitor of metalloproteinases‐1 (TIMP‐1), but not TIMP‐2, has potent growth‐promoting activity for a wide range of human and bovine cells, TIMP‐1 seems to be a new cell‐growth factor in serum and to stimulate the cells independently of its inhibitory activity.
Inhibitory effect of oryzacystatins and a truncation mutant on the replication of poliovirus in infected Vero cells
Authors: Kondo Hiroto , Ijiri Sumiko , Abe Keiko , Maeda Hiroshi , Arai Soichi
Published: July 2002

Poliovirus, a picornavirus family member, requires the processing of its poly‐protein by its own cysteine proteinase for replication. Oryzacystatin‐I and oryzacystatin‐II, proteinaceous cysteine proteinase inhibitors (cystatins) of rice seed origin, were found to inhibit the replication of poliovirus effectively in infected Vero cells in vitro. Truncated oryzacystatin‐I, which lacks the NH2‐terminal 25 amino acid residues of the intact protein, is an even more effective inhibitor, eliciting its effect at concentrations of less than 0.23 nmol/ml. The low molecular weight cysteine proteinase inhibitors, E‐64, E‐64C and loxistatin, showed no anti‐viral effect at any concentration investigated.
Relationship between primary structure and activity in exorphins and endogenous opioid peptides
Authors: Ya. Bakalkin Georgy , Demuth Hans-Ulrich , Nyberg Fred
Published: July 2002

We have found a correlation between the certain characteristics of primary structure and biologic activity in exorphins and endogenous opioid peptide family. The characteristics of primary structure are the content of certain segment pairs as well as the density of their arrangement in a peptide. These segment pairs represent basic elements of the regulatory peptide primary structure pattern, which was found recently [Dokl. Akad. Nauk USSR 289 (1986) 721–724; Int. J. Peptide Prot. Res. 38 (1991) 505–510].
The ZNF35 human zinc finger gene encodes a sequence‐specific DNA‐binding protein
Authors: Pengue Gina , Cannada-Bartoli Paola , Lania Luigi
Published: July 2002

We developed a rapid method to determine DNA‐binding sites for putative DNA‐binding proteins. This procedure has been successfully used to define a specific consensus site for the human ZNF35 zinc finger gene. ZNF35 encodes a 58‐kDA polypeptide containing 11 consecutive finger motifs located at the amino terminus, and an acidic domain located at the carboxy terminus. These features suggest that ZNF35 is a site‐specific DNA‐binding protein involved in the regulation of gene expression. We have expressed the ZNF35 protein from E. coli and have employed a Southwestem‐polymerase chain reaction method using random oligonucleotides to identify its high‐affinity binding site. The core sequence for the ZNF35 protein‐binding site is 5'‐C/GC/GAAG/TA‐3'.
Topological characterization and modeling of the 3D structure of lipase from Pseudomonas aeruginosa
Authors: Jaeger Karl-Erich , Ransac Stéphane , Koch Heinrich B. , Ferrato Francine , Dijkstra Bauke W.
Published: July 2002

Lipase from Pseudomonas aeruginosa is a M
r, 29 kDa protein with a single functional disulfide bond as shown by a shift in electrophoretic mobility after treatment with dithiothreitol and iodoacetamide. Limited proteolysis of lipase with Staphylococcus aureus protease V8 resulted in cleavage after amino acid residues Asp38 and Glu46. Comparison of the lipase amino acid sequence with those of other hydrolases with known 3D structures indicated that the folding pattern might be compatible with the α/β hydrolase fold, thereby allowing us to construct a 3D model which fitted the biochemical properties. The model predicts a catalytic triad consisting of Ser82, Asp229 and His251, and contains a disulfide bond connecting residues Cys183 and Cys235. Residues Asp38 and Glu46 are located at the surface of the enzyme, whereas the disulfide bond is rather inaccessible, which is in agreement with the finding that the protein needed to be partly unfolded before a reduction of the disulfide bond could take place. A striking prediction from the model was the lack of a lid‐like α‐helical loop structure covering the active site which confers to other well‐characterized lipases a unique property known as interfacial activation. Experimental determination of lipase activity under conditions where the substrate existed either as monomeric solutions or aggregates confirmed the absence of interfacial activation.
Pro‐urokinase and prekallikrein are both associated with platelets
Authors: Gurewich Victor , Johnstone Michael , Loza Jean-Pierre , Pannell Ralph
Published: July 2002

The contact‐dependent intrinsic pathway of fibrinolysis involving factor XII, prekallikrein (PK) and pro‐urokinase (pro‐UK) remains poorly understood. Casein autography of washed, intact platelets revealed both PK and pro‐UK. Accordingly, platelets may mediate physiological thrombolysis by this pathway since factor XIIa activates PK and kallikrein activates pro‐UK. Acid washing dissociated PK but not pro‐UK from platelets. Exogenous pro‐UK was specifically incorporated by platelets from the ambient fluid and similarly could not be dissociated from intact platelets. Therefore, platelets may also mediate an effect from therapeutically administered pro‐UK by prolonging its half‐life.
Determination and mutational analysis of the phosphorylation site in the hypusine‐containing protein Hyp2p
Authors: Klier Hannelore , Wöhl Thorsten , Eckerskorn Christoph , Magdolen Viktor , Lottspeich Friedrich
Published: July 2002

Electrospray mass spectrometry of the purified isoforms of the hypusine‐containing protein of Saccharomyces cerevisiae Hyp2p suggested a phosphorylation of the acidic isoform, which was confirmed by phosphatase treatment. The phosphorylation site was mapped to the N‐acetylated serine residue in position no. 1 by mass spectrometric analysis of enzymatic fragments. Mutation of this serine residue gives rise to only the basic isoform, confirming our protein chemical data. As this mutation has no effect on cell viability or growth rate, the unphosphorylated isoform is sufficient to exert the essential in vivo function of Hyp2p.
A cdc2‐related kinase PSSALRE/cdk5 is homologous with the 30 kDa subunit of tau protein kinase II, a proline‐directed protein kinase associated with microtubule
Authors: Kobayashi Shunsuke , Ishiguro Koichi , Omori Akira , Takamatsu Masako , Arioka Manabu , Imahori Kazutomo , Uchida Tsuneko
Published: July 2002

We previously reported that tau protein kinase II (TPKII) from bovine brain was composed of 30 kDa and 23 kDa subunits. The 30 kDa subunit of TPKII can be regarded as a catalytic subunit because of its ATP‐binding activity. Antibodies directed against TPKII‐phosphorylated tau also reacted with tau phosphorylated by cdc2 kinase obtained from starfish oocytes, indicating that TPKII and cdc2 kinase phosphorylate the same sites. We determined the amino acid sequence of the 30 kDa subunit and found it to be homologous with a cdc2‐related kinase, PSSALRE/cdk5. Moreover, an antibody against PSSALRE/cdk5 reacted with the 30 kDa subunit. These results indicate that the 30 kDa subunit of TPKII is bovine homologue of PSSALRE/cdk5. Expression of the 30 kDa subunit mRNA was enhanced in juvenile rat brain. This result supports our previous hypothesis that the kinase works actively in juvenile brain.
ω‐Agatoxin‐IVA‐sensitive calcium channels in bovine chromaffin cells
Authors: Albillos Almudena , García Antonio G. , Gandía Luis
Published: July 2002

A large component of the whole‐cell currents through Ca2+ channels in bovine adrenomedullary chromaffin cells has been shown to be insensitive to both L‐type and N‐type Ca2+ channel Mockers, suggesting the existence of a third type of Ca2+ channel. In the present paper, ω‐agatoxin‐IVA (AgTx), a selective blocker of P‐type Ca2+ channels in mammalian neurons, has been used to investigate the presence of this subtype of Ca2+ channel in bovine chromaffin cells. Barium currents (I
Ba) through Ca2+ channels were recorded in whole‐cell patch‐clamped bovine chromaffin cells. I
Ba was blocked by AgTx in a dose‐dependent and irreversible manner. At the maximal concentration used (1 μM), AgTx inhibited T
Ba by 49.5 ± 3%. Such a blockade was also present when bovine chromaffin cells were pretreated with 10 μM fumidipine, a novel 1,4‐dihydropyridine L‐type channel blocker, and after treatment with 1 μM of the N‐type channel blocker, ω‐conotoxin GVIA (CgTx). A combination of these three types of Ca2+ channel blockers suppressed the macroscopic Ba2+ currents by 88%. We conclude that bovine chromaffin cells, in addition to N‐ and L‐type Ca2+ channels, possess a P‐like component in their whole‐cell currents through the Ca2+ channels.
Sequence and structure similarities of cathepsin B from the parasite Schistosoma mansoni and human liver
Authors: Klinkert Mo-Quen , Cioli Donato , Shaw Elliott , Turk Vito , Bode Wolfram , Butler Richard
Published: July 2002

A three‐dimensional structure of Schistosoma mansoni cathepsin B was modelled using the coordinates of the crystal structure of the human liver enzyme. Both enzymes appear to share remarkable structural similarity. However, an examination of the models complexed with two synthetic inhibitors revealed differences in inhibitor binding, as confirmed by differences in the 50% inhibitory concentration of the same inhibitor.
Affinity modification of human immunodeficiency virus reverse transcriptase and DNA template by photoreactive dCTP analogs
Authors: Doronin S.V. , Dobrikov M.I. , Buckle M. , Roux P. , Buc H. , Lavrik O.I.
Published: July 2002

New base‐substituted analogs of dCTP containing an azido group have been synthesized and applied to a selective photoaffinity modification of HIV‐RT (p66/p51 heterodimer). The labeling of only the 66 kDa subunit of HIV‐RT was detected when the enzyme was first irradiated with the analogs and then template (5′‐(d)GGTTAAATAAAATAGTAAGAATGTATAGCCCCTACCA‐3′) and 5′ 32P end‐labeled 3′‐(d)TTACATATCGGGGATGGT‐5′primer were added. The 5′ 32P end‐labeled primer elongated by dCTP analogs in the presence of both HIV‐RT and DNA template is able to modify both subunits of HIV‐RT and DNA template. This way of specific cross‐linking to both DNA (RNA) template and HIV‐RT opens up new possibilities to study the HIV‐RT active site.
The antiprogestatin drug RU 486 potentiates doxorubicin cytotoxicity in multidrug resistant cells through inhibition of P‐glycoprotein function
Authors: Lecureur Valérie , Fardel Olivier , Guillouzo André
Published: July 2002

The antiprogestatin drug RU 486 was examined for its effect on doxorubicin cellular retention and cytotoxicity in multidrug resistant cells overexpressing P‐glycoprotein (P‐gp). RU 486 was shown to strongly enhance intracellular accumulation of doxorubicin in both rat hepatoma RHC1 and human leukemia K562 R7 drug‐resistant cells but had no action in SDVI drug‐sensitive liver cells. The antiprogestatin drug when used at 10 μM, a concentration close to plasma concentrations achievable in humans, was able to hugely increase the sensitivity of RHC1 cells to doxorubicin. RU 486 appeared to prevent the P‐gp‐mediated doxorubicin efflux out of RHC1 cells and was demonstrated to interfere directly with P‐gp drug binding sites since it blocked P‐gp labelling by the photoactivable P‐gp ligand azidopine. These results thus demonstrate that RU 486 can downmodulate anticancer drug resistance through inhibition of P‐gp function.
Activity of the E75E76 mutant of the α subunit of casein kinase II from Xenopus laevis
Authors: Gatica Marta , Jedlicki Ana , Allende Catherine C. , Allende Jorge E.
Published: July 2002

The cDNA gene coding for the α subunit of Xenopus laevis casein kinase II was mutated using the overlap extension PCR method. The mutation substituted glutamic acids for Lys75 and Lys76, changing the charge distribution of a very basic sequence found in the α subunit. Expression of the mutated cDNA in a pT7‐7 vector in E. coli yielded an active mutant recombinant protein that was extensively purified. This mutant was not significantly affected in its app. K
m for casein or a model peptide substrate, nor in its interaction with the activating β subunit. Inhibition by quercetin and by 5,6‐dichloro‐1‐β‐d‐ribofuranosyl benzimidazole was also the same for mutant and wild type subunits. However, the CKII αE75E76 mutant was at least one order of magnitude less sensitive to inhibition by polyanionic inhibitors such as heparin, poly U, copolyglutamic acid:tyrosine (4:1) and 2,3 diphosphoglycerate.
Reduced hepatic fatty acid oxidation in fasting PPARα null mice is due to impaired mitochondrial hydroxymethylglutaryl‐CoA synthase gene expression
Authors: Le May Cédric , Pineau Thierry , Bigot Karine , Kohl Claude , Girard Jean , Pégorier Jean-Paul
Published: July 2002

Glucose and fatty acid metabolism (oxidation versus esterification) has been measured in hepatocytes isolated from 24 h starved peroxisome proliferator‐activated receptor‐α (PPARα) null and wild‐type mice. In PPARα null mice, the development of hypoglycemia during starvation was due to a reduced capacity for hepatic gluconeogenesis secondary to a 70% lower rate of fatty acid oxidation. This was not due to inappropriate expression of the hepatic CPT I gene, which was similar in both genotypes, but to impaired mitochondrial hydroxymethylglutaryl‐CoA synthase gene expression in the PPARα null mouse liver. We also demonstrate that hepatic steatosis of fasting PPARα null mice was not due to enhanced triglyceride synthesis.
Phosphorylation of the endothelial nitric oxide synthase at Ser‐1177 is required for VEGF‐induced endothelial cell migration
Authors: Dimmeler Stefanie , Dernbach Elisabeth , Zeiher Andreas M
Published: July 2002

Vascular endothelial growth factor (VEGF) stimulates endothelial cell (EC) migration. The protein kinase Akt activates the endothelial NO synthase (eNOS) by phosphorylation of Ser‐1177. Therefore, we investigated the contribution of Akt‐mediated eNOS phosphorylation to VEGF‐induced EC migration. Inhibition of NO synthase or overexpression of a dominant negative Akt abrogated VEGF‐induced cell migration. In contrast, overexpression of constitutively active Akt was sufficient to induce cell migration. Moreover, transfection of an Akt site phospho‐mimetic eNOS (S1177D) potently stimulated EC migration, whereas a non‐phosphorylatable mutant (S1177A) inhibited VEGF‐induced EC migration. Our data indicate that eNOS activation via phosphorylation of Ser‐1177 by Akt is necessary and sufficient for VEGF‐mediated EC migration.
Phosphorylation of murine homeodomain protein Dlx3 by protein kinase C
Authors: Park Geon Tae , Denning Mitchell F. , Morasso Maria I.
Published: July 2002

The Dlx3 homeodomain gene is expressed in terminally differentiated murine epidermal cells. As demonstrated for differentiation‐specific granular markers, Dlx3 is activated in primary mouse keratinocytes cultured in vitro by increasing the level of the extracellular Ca2+. This activation is mediated through a protein kinase C‐dependent (PKC) pathway. In this study, we investigated whether PKC can modulate the activity of murine Dlx3 protein. Using in vitro kinase assays, we show that PKC enzymes phosphorylate the Dlx3 protein. Using keratinocyte nuclear extracts for the kinase reaction, we determined that Dlx3 protein is phosphorylated, and the phosphorylation is inhibited by the PKC‐specific inhibitor GF109203X, suggesting that Dlx3 is phosphorylated by PKC in vivo. Of the PKC isoforms present in the epidermis, we tested α, δ, ϵ and ζ. Dlx3 is primarily phosphorylated by PKCα. By deletion and mutational analysis, we show that the serine residue S138, located in the homeodomain of Dlx3 protein, was specifically phosphorylated by PKC. The phosphorylation of purified Dlx3 proteins by PKC partially inhibited formation of complexes between Dlx3 protein and DNA. These results suggest that Dlx3 protein can be directly phosphorylated by PKC and this affects the DNA binding activity of Dlx3.
Structure, function and regulation of Ca2+‐sensitive cytosolic phospholipase A2 (cPLA2)
Authors: Kramer Ruth M , Sharp John D
Published: July 2002

The 85‐kDa cytosolic PLA2 (cPLA2) is present in many cells and tissues and its unusual functional properties and catalytic mechanism are being elucidated. Notably, cPLA2 becomes catalytically active in the presence of free Ca2+ concentrations as present in stimulated cells and preferentially cleaves arachidonic acid‐containing phospholipids. A variety of agonists, growth factors and cytokines, as well as stressful stimuli activate cPLA2 to hydrolyze cellular phospholipids thereby liberating fatty acids and lysophospholipids and providing the precursor substrates for the biosynthesis of eicosanoids and platelet‐activating factor. These products of cPLA2 contribute to inflammatory and degenerative disease states and cPLA2 is therefore an attractive target for the development of novel therapies.
RNA editing in metazoan mitochondria: staying fit without sex
Authors: Börner G.Valentin , Yokobori Shin-ichi , Mörl Mario , Dörner Marion , Pääbo Svante
Published: July 2002

RNA editing subsumes a number of functionally different mechanisms which have in common that they change the nucleotide sequence of RNA transcripts such that they become different from what would conventionally be predicted from their gene sequences. RNA editing has now been found in the organelles of numerous organisms as well as in a few nuclear transcripts. Most recently, it was shown to affect tRNAs in the mitochondria of several animals. The occurrence and evolutionary persistence of RNA editing is perplexing since backmutations in the genes might be assumed rapidly to eliminate the need for ‘correction’ of the gene sequences at the post‐transcriptional level. Here, we review the recent RNA editing systems discovered in animal mitochondria and propose that they have arisen as a mechanism counteracting the accumulation of mutations that occurs in asexual genetic system.
A novel subtype of G‐protein‐coupled receptor kinase, GRK7, in teleost cone photoreceptors
Authors: Hisatomi Osamu , Matsuda Shinji , Satoh Takunori , Kotaka Shuichi , Imanishi Yoshikazu , Tokunaga Fumio
Published: July 2002

Two kinds of retinal cDNA fragments (OlGRK‐R and ‐C) encoding the putative G‐protein‐coupled receptor kinases (GRKs) were isolated from medaka, Oryzias latipes. OlGRK‐R appears to be closely related to the rhodopsin kinase (RK) found in the outer segments of mammalian photoreceptors, but the deduced amino acid sequence of OlGRK‐C shows less than 50% identity to those of GRKs known to date, suggesting that OlGRK‐C is a novel GRK subtype (GRK7). The mRNA of OlGRK‐R is detectable in rods, and that of OlGRK‐C is found in all four types of cone photoreceptor. The C‐terminal of OlGRK‐R has a consensus sequence for farnesylation, whereas, surprisingly, OlGRK‐C has a consensus sequence for geranylgeranylation. Our result are consistent with the concept that lower vertebrates have rod‐ and cone‐specific opsin kinases.
The hexokinase 2 protein participates in regulatory DNA‐protein complexes necessary for glucose repression of the SUC2 gene in Saccharomyces cerevisiae
Authors: Herrero Pilar , Martı́nez-Campa Carlos , Moreno Fernando
Published: July 2002

The HXK2 gene plays an important role in glucose repression in the yeast Saccharomyces cerevisiae. Recently we have described that the HXK2 gene product, isoenzyme 2 of hexokinase, is located both in the nucleus and in the cytoplasm of S. cerevisiae cells. In this work we used deletion analysis to identify the essential part of the protein‐mediating nuclear localisation. Determinations of fructose‐kinase activity and immunoblot analysis using anti‐Hxk2 antibodies in isolated nuclei, together with observations of the fluorescence distribution of Hxk2‐GFP fusion protein in cells transformed with an HXK2::gfp mutant gene, indicated that the decapeptide KKPQARKGSM, located between amino acid residues 7 and 16 of hexokinase 2, is important for nuclear localisation of the protein. Further experimental evidence, measuring invertase activity in wild‐type and mutant cells expressing a truncated version of the Hxk2 protein unable to enter the nucleus, shows that a nuclear localisation of Hxk2 is necessary for glucose repression signalling of the SUC2 gene. Furthermore, we demonstrate using gel mobility shift analysis that Hxk2 participates in DNA‐protein complexes with cis‐acting regulatory elements of the SUC2 gene promoter.
A cooperative model for protonmotive heme‐copper oxidases. The role of heme a in the proton pump of cytochrome c oxidase
Authors: Papa Sergio , Capitanio Nazzareno , Villani Gaetano
Published: July 2002

Oxido‐reductions of metal centers in cytochrome c oxidase are linked to pK shifts of acidic groups in the enzyme (redox Bohr effects). The linkage at heme a results in proton uptake from the inner space upon reduction and proton release in the external space upon oxidation of the metal. The relationship of this process to the features of the proton pump in cytochrome c oxidase and its atomic structure revealed by X‐ray crystallography to 2.8–2.3 Å resolution is examined. A mechanism for the proton pump of cytochrome c oxidase, based on cooperative coupling at heme a, is proposed.
Reprogramming of TIMP‐1 and TIMP‐3 expression profiles in brain microvascular endothelial cells and astrocytes in response to proinflammatory cytokines
Authors: Bugno Marcin , Witek Barbara , Bereta Joanna , Bereta Michal , Edwards Dylan R. , Kordula Tomasz
Published: July 2002

Cytokine‐dependent regulation of tissue inhibitors of metalloproteinases (TIMPs) expression provides an important mechanism for controlling the activity of matrix metalloproteinases. We present data indicating that during inflammatory processes TIMP‐1 and TIMP‐3 may be involved in the proteolytic remodeling of subendothelial basement membrane of the brain microvascular system, a key step during leukocyte migration into the brain perivascular tissue. In brain endothelial cells the expression of TIMP‐1 is dramatically up‐regulated by major proinflammatory cytokines, with the combination of interleukin‐1β (IL‐1β) and tumor necrosis factor‐α (TNFα) exhibiting the strongest synergistic stimulation. Simultaneously, IL‐1β/TNFα almost completely blocks TIMP‐3 expression. Both synergistic effects are dose‐dependent within the concentration range 0.05–5 ng/ml of both cytokines and correlate with the expression of inducible nitric oxide synthase, an endothelial cell activation marker. Down‐regulation of TIMP‐3 expression is also detected in astrocytes treated with TNFα or IFN‐γ, whereas oncostatin M as well as TNFα up‐regulate TIMP‐1 mRNA level. We propose that the cytokine‐modified balance between TIMP‐1 and TIMP‐3 expression provides a potential mechanism involved in the regulation of microvascular basement membrane proteolysis.
The phosphoinositide 3‐kinase/Akt pathway is activated by daunorubicin in human acute myeloid leukemia cell lines
Authors: Plo I. , Bettaïeb A. , Payrastre B. , Mansat-De Mas V. , Bordier C. , Rousse A. , Kowalski-Chauvel A. , Laurent G. , Lautier D.
Published: July 2002

Daunorubicin induces apoptosis in myeloid leukemia cells by activation of neutral sphingomyelinase and ceramide generation occurring 4–10 min after daunorubicin addition. We show here that daunorubicin is able to increase the phosphoinositide 3‐kinase activity and enhance intracellular phosphoinositide 3‐kinase lipid products prior to ceramide generation. Daunorubicin activates Akt, a downstream phosphoinositide 3‐kinase effector. Interestingly, the phosphoinositide 3‐kinase inhibitors wortmannin and LY294002 accelerate daunorubicin‐induced apoptosis in U937 cells. The phosphoinositide 3‐kinase/Akt pathway has been involved in cell survival following serum deprivation, tumor necrosis factor α, anti‐Fas and UV radiations. Our results suggest that anti‐tumor agents such as daunorubicin may also activate anti‐apoptotic signals that could contribute to drug resistance.
Stabilization of iron regulatory protein 2, IRP2, by aluminum
Authors: Yamanaka Koji , Minato Nagahiro , Iwai Kazuhiro
Published: July 2002

Iron regulatory protein 2 (IRP2) is one of the central regulators of iron homeostasis. IRP2 regulates expression of molecules involved in iron metabolism by binding to iron responsive elements (IREs) in the transcripts of those molecules in iron depletion. IRP2 is regulated by the accelerated degradation initiated by the iron‐catalyzed oxidation. Here we report that aluminum antagonizes the iron‐induced decrease in IRE binding activity of IRP2. Aluminum also inhibits iron‐induced oxidation of IRP2 in vitro. These results suggest that aluminum stabilizes IRP2 by interfering with the iron‐catalyzed oxidation, which results in perturbation of iron metabolism.
A profile of differentially expressed genes in primary colorectal cancer using suppression subtractive hybridization
Authors: Hufton Simon E. , Moerkerk Peter T. , Brandwijk Ricardo , de Bruïne Adriaan P. , Arends Jan-Willem , Hoogenboom Hennie R.
Published: July 2002

As a step towards understanding the complex differences between normal cells and cancer cells, we have used suppression subtractive hybridization (SSH) to generate a profile of genes overexpressed in primary colorectal cancer (CRC). From a 35 000 clone SSH‐cDNA repertoire, we have screened 400 random clones by reverse Northern blotting, of which 45 clones were scored as overexpressed in tumor compared to matched normal mucosa. Sequencing showed 37 different genes and of these, 16 genes corresponded to known genes in the public databases. Twelve genes, including Smad5 and Fls353, have previously been shown to be overexpressed in CRC. A series of known genes which have not previously been reported to be overexpressed in cancer were also recovered: Hsc70, PBEF, ribophorin II and Ese‐3B. The remaining 21 genes have as yet no functional annotation. These results show that SSH in conjunction with high throughput screening provides a very efficient means to produce a broad profile of genes differentially expressed in cancer. Some of the genes identified may provide novel points of therapeutic intervention.
A global overview of ethical issues in women's health
Authors: Cain J.M.
Published: July 2002

The fundamental denial of basic human rights to reproductive choice, freedom from violence, and economic and educational development for women remains the major underpinning ethical issue in worldwide women's healthcare. The ability to choose when to have children, whether to have prenatal diagnosis or to make uncoerced choices at the end of life all hinge on the independence of each woman's ability to make choices about their own healthcare within the constraints of the health resources available to them. Technologic advances increase the complexity of assuring that the rights and best interest of the woman, the fetus or child, and society itself are balanced equitably in both the healthcare setting as well as the development of national or international policies and standards. The obstetrician/gynecologist, as an advocate for women's health worldwide, has an ethical obligation to assure human rights are extended to women and the obligation to assure that the care received is the best available.
Changes in women's health in the Baltic republics of Lithuania, Latvia and Estonia during 1970–1997
Authors: Nadišauskien≐ R.J. , Padaiga Z.
Published: July 2002

The rapid political, economic and social changes occurring in the Baltic republics of Estonia, Latvia and Lithuania fundamentally affect female health. Demographic trends, morbidity and mortality indicators point to a general decline in the status of women's health in the three Baltic republics since their independence from the Soviet Union. The transition period from socialist to market economy has clearly taken a toll in women's health. These have to be taken into consideration by health authorities in Lithuania, Latvia, Estonia as well as the European Union during the undergoing reforms being planned for healthcare systems in all EU countries in accession.
Smoking and women's health
Authors: Seltzer V
Published: July 2002

Each year more than 600 000 women have deaths associated with cigarette smoking. In addition, cigarette smoking is associated with a wide array of morbidities (such as osteoporosis, cardiovascular disease, and adverse pregnancy outcomes). Two hundred million women smoke worldwide, and this number appears to be rising, particularly in developing countries. Obstetrician–gynecologists can play a role in reducing morbidity and mortality from cigarette smoking by educating women about the dangers, advising them not to smoke, and assisting those who do smoke to quit.