bluuebunny/crossref_metadata_2025 huggingface dataset:
An Atypical Meningioma Presenting at an Unusual Site
Authors: Bamanikar Sunita , Ranjan Sadbhavana , Kumar Harsh , Gore Charusheela , Kambale Tushar
Published: January 2021

Meningiomas are tumours that originate from the arachnoid cells (meningocytes) and the majority are benign grade I tumours according to World Health Organisation (WHO). Chordoid meningioma is an uncommon variant of meningioma and corresponds to grade II tumour in WHO classification of tumours of the Nervous System 2016, because of its more aggressive behaviour and increased likelihood of recurrence. These meningiomas may appear extracranially (i.e. head and neck region, sinonasal tract, ear, temporal bone, scalp, etc) in only 2% cases. The histopathological and immunohistochemical evaluation is usually diagnostic. Here, the authors present a case of Chordoid meningioma in a 32-year-old patient who presented with complaints of nasal obstruction clinically suspected to be due to nasal polyp.
Utility of TP53 in Breast Carcinoma Immunophenotypes
Authors: Jaggi Ria , Shukla Samarth , Acharya Sourya , Vagha Sunita
Published: January 2021

Breast cancer is a heterogeneous disease and has significant variability in presentation, treatment response, and prognosis. The management of carcinoma breast is currently based on immunophenotypes and Tumour Nodes Metastasis (TNM) staging. The aim of the study is to review the literature and to look for treatment guidelines of carcinoma breast, the role of immunophenotypes in treatment of carcinoma breast, TP53 mutation in breast cancer, and the relationship of TP53 mutation with immunophenotypes, histological grade, efficacy of chemotherapy, and BRCA (Breast Cancer gene) mutation. Pubmed database was researched and a total of 510 articles were analysed. A total of one meta-analysis, one randomised controlled trial, one literature review, nine prospective studies, and three retrospective studies were included for further analysis. It was observed that TP53 mutation is associated with poor overall survival. It was also found to be inversely associated with the Estrogen Receptor (ER) status and so it was seen more commonly in basal type and HER2/neu enriched breast cancer. There is a need for further studies to establish the definite association between TP53 and immunophenotypes so that TP53 alone can be used as a guide for management in carcinoma breast at low resource centres.
Histopathological Spectrum of Lesions in Lungs on Post-mortem Specimen in a Tertiary Centre of Bastar Region- A Retrospective Study
Authors: Dhruw Deepika , Chikhlikar Kasturi , Nayak Kalpana , Thakur Nitya , Singh Bhanupratap , Meshram Avinash
Published: January 2021

Introduction: Lungs are the major organ involved in a number of infectious, inflammatory and occupational disease, secondarily involved in almost all form of terminal disease. So many people around the world suffer from preventable lung disease. Many a times it has been found that when gross pathology could not help to evaluate cause of death, histopathology provide the valuable information. Aim: To study the spectrum of histopathological finding in lung autopsy and the incidental findings identified during histopathological examination. Materials and Methods: This was a retrospective study done in the Department of Pathology, Lt B.R.K.M G.M.C, Bastar, Chhattisgarh, India, over a period of 10 years i.e., from January 2010 to December 2019. The study consisted of Lung specimens (474 cases) from medico-legal autopsies, irrespective of their age and sex, received during this period. Gross and Microscopic features were documented, and diagnosis was made. The results were analysed based on gross findings and the histopathological examination. Results: Among 474 cases studied during period of 10 years, maximum cases were seen in 30-39 (141 cases) years of age group. Males were more commonly affected 345 (73%) as compared to Females 129 (27%). Pathological findings of Lung were seen in 441 cases, of which Pulmonary Oedema with Congestion was found in 352 cases, along with Intra-alveolar Haemorrhage in 41 cases, Bronchopneumonia in 14 cases, Lobar Pneumonia in 11 cases, seven cases of Tuberculosis, Interstitial Pneumonia in seven cases, Vegetative material in three cases, Emphysema in three cases, Aspiration pnuemonitis in two cases and one case of Chronic Bronchitis. Conclusion: Autopsy study of lung specimens gives valuable information, improves clinical diagnosis and provides diagnostic setup for better clinical assessment. Histopathological examination proves to be the great diagnostic tool in the identification of lung lesions which were incidental finding or direct cause of death. Limitation was non-availability of large specimens, detailed clinical history and autolysis of the organ.
Novel Coronavirus Infection: A Review on Haematological Markers of Disease Severity
Authors: Ugwu Angela Ogechukwu , Nwagha Theresa Ukamaka
Published: January 2021

The Corornavirus Disease (COVID-19) virus infection has a wide range of presentation- asymptomatic, mild, severe and critical forms that often lead to death from respiratory failure. There is a strong relationship between the severity of COVID-19 infection and some haematological parameters. Patients often present with lymphocytopenia at diagnosis despite having a normal total white cell count. The degree of lymphocytopenia could predict the progression to pneumonia and subsequent need for ventilator support due to respiratory failure. Apart from lymphocytopenia, thrombocytopenia has been linked with increased severity of COVID-19 symptoms. The lymphocyte-platelet ratio has been found to a better marker for disease severity than isolated lymphocytopenia or thrombocytopenia. COVID-19 patients have been found to be at increased risk of Venous Thromboembolism (VTE). There is elevation of D-dimers, abnormalities of the Prothrombin Time (PT) and activated Partial Thromboplastin Time (aPTT) among hospitalised COVID-19 patients. This has necessitated the use of prophylactic anticoagulation even in the early phases of the infection.
Myeloma Cast Nephropathy Manifesting only as Unexplained Acute Renal Failure
Authors: Raman Sarojini , Rout Nikunj Kishore
Published: January 2021

Multiple Myeloma (MM) is characterised by clonal B cell proliferation affecting elderly age group and involving various organ systems namely haematological, renal and skeletal system. Kidney may be affected in 50% of cases of MM. Though, Chronic Kidney Disease (CKD) is usually seen in MM, unusual presentations have been documented. The present case is of a 50-year-old female with complains of breathlessness and vague generalised symptoms. Routine tests showed blood urea level of 90 mg/dL and serum creatinine of 8.3 mg/dL. Further investigations revealed 24 hour protein level 48.5 gm/day, Erythrocyte Sedimentation Rate (ESR)-126 mm/1st hour, cast nephropathy in renal biopsy. Immunohistochemical (IHC) study on renal biopsy revealed kappa light chain deposits in tubules, raised kappa light chains (3280.00 mg/L) in serum Free Light Chain (FLC) assay and MM in bone marrow aspiration and biopsy study. So, MM should be considered in differential diagnosis in elderly patients presenting with acute severe renal failure.
Evaluation of Bactericidal and Fungicidal Efficacy of Strychno spotatorum Linn. (Nirmali) Seeds
Authors: Sharmila Chandiran , Selvam Rajendiran , Subramanian Sorimuthu Pillai
Published: January 2021

Aim: Diseases due to pathogenic microbes pose a great burden on human health and they have been correlated with socioeconomic, environmental, and ecological factors. The threat due to infectious diseases is further intensified by the continued emergence of new and multidrug resistant microorganisms. This scenario warrants a continuous search for antimicrobial agents preferably of plant origin due to their availability, accessibility, and affordability. The present study was aimed to evaluate the antibacterial and antifungal properties of Strychnos potatorum Linn (Nirmali) seeds using common pathogenic bacterial and fungal strains.

Methodology: Fresh and matured S. potatorum seeds were used for the present study. The powdered seeds were delipidated with petroleum ether (60-80°C) overnight and the extract was filtered. Soxhalation was performed with 95% ethanol to extract the phyto-ingredients from the seeds. Four Gram positive, four Gram negative, and eight fungal strains were used. The antimicrobial activity was evaluated by disc diffusion and well diffusion methods. The Minimum inhibitory concentration (MIC) Minimum bactericidal concentrations (MBC), Minimum fungicidal concentration (MFC) were assayed.

Results: The data obtained through the disc diffusion, well diffusion, the minimum bactericidal concentration, and minimum fungicidal concentrations revealed that the ethanolic extract of the seeds possesses significant antibacterial and antifungal activities. The results obtained were compared with standard drugs widely prescribed for antimicrobial therapy.

Conclusion: The present study provides the scientific rationale for the use of Strychnos potatorum seeds in traditional medicine and a rich source of phytochemicals having significant antimicrobial activities.
Protectant Effect of Vegetable Oils against Cowpea Weevil (Callosobruchus maculatus) on Stored Cowpea [Vigna unguiculata (L.) Walp]
Authors: Yoriyo Kennedy Poloma , Usman Garba , Abba Ezra , Degri Michael Mamman
Published: January 2021

Cowpea is one of the common edible annual herbaceous legume. Callosobruchus maculatus is one of the common post-harvest pest of cowpea.This work was aimed at determining the protectant effect of five vegetable oils; coconut oil, cotton seed oil, groundnut oil, palm oil and sesame oil for the protection of stored cowpea against cowpea weevil (Callosobruchus maculatus).The study was conducted in Gombe State University between October, 2018 and April, 2019. Black eye seeds were used for the experiment. A completely randomized design with five replicates per treatment was used.Black eyed seeds (susceptible variety) used for the experiment were subjected to different oil treatments namely: coconut, cotton, groundnut, palm and sesame oils applied at 0.4, 0.8 and 1.2 ml/100 g of cowpea equivalent to 4, 8 and 12 kg. Effect of the oils on weight lost and seed germination was also tested.Percentage adult mortality at 12 ml/Kg revealed that all the five oils killed 100% of the insects. Among the different edible oils evaluated, cotton seed oil was more effective killing 95% of the insect at 4 ml/kg and 100% at 8 ml/kg. The lowest mortality was recorded in the treatment with palm oil with 60 and 91.67% mortality at 4 and 8 ml/kg dose treatment respectively. Minimum percentage weight loss after 90 days of storage was observed in grains treated with cotton seed oil (1.95%) followed by sesame oil (2.00%) and groundnut oil (2.38%) at 12 ml/kg grains. Cotton seed oil, groundnut oil and sesame oil at doses between 8 and 12 ml/kg could be effective for protecting cowpea in storage against cowpea weevil for 90 days of storage.All the treatments indicated minimal effect on the germination of cowpea. The 8 ml/kg of cotton seed, groundnut and sesameoils investigated are promising bio friendly preservatives that could serve as an alternative formulations to synthetic chemical based insecticides for storage of cowpea.
Glucokinase microsomique du foie de rat. Un enzyme régulateur de la glycolyse?
Authors: Berthillier G. , Got R.
Published: July 2002

Kinetic properties of microsomal glucokinase of rat liver have been investigated. The enzyme is inhibited by ATP and activated or deinhibited by AMP. It displays properties associated with a typical allosteric enzyme which could realize a feedback control of glycolysis.
Die chemische struktur der biosynthetischen vorstufe des squalens
Authors: Wasner H. , Lynen F.
Published: July 2002

Presqualenyl‐pyrophosphate (PSPP) was synthesized from farnesyl‐pyrophosphate (FPP). The purified product could be transformed into a squalene in 90% yield. The structure of PSPP was established by the following experiments:

PSPP displays a remarkably acid‐labile phosphate—ester bond. Analogous to FPP it was possible to stabilize this bond by the addition of bromine. This indicates a structure of the allylester type.

On acid hydrolysis PSPP splits off not only the pyrophosphate but also water. This may be best explained by the presence of a tertiary hydroxyl group in PSPP.

The pyrophosphate group of PSPP could be split by prostatic phosphatase. In gas‐liquid‐chromatography the trimethyl‐silylated product gave a single peak. From the mass spectra of this compound and of the corresponding alcohol the expected molecular weight of 426 could be verified for the latter.

Determining the 3H/14C ratio in 1‐3H2‐414C‐FPP and in PSPP and squalene, synthesized from it, only three 3H‐atoms could be detected in PSPP and in squalene.

Ozonisation of PSPP, synthesized from 1‐14C‐FPP, gave radioactive malondialdehyde, which was characterised as azobenzene‐malondialdehyde and 4‐azobenzene‐1‐phenyl‐pyrazole. The experimental results are in agreement with the following structure of 2, 6, 10, 15, 19, 23‐hexamethyl‐n‐tetracosa‐2, 6, 11, 14, 18, 22‐hexaen‐10‐yl‐pyrophosphate for PSPP.
Stimulation by silybin, a eukaryotic feature of archaebacterial RNA polymerases
Authors: Schnabel R. , Sonnenbichler J. , Zillig W.
Published: July 2002

Transcription of native DNA by DNA‐dependent RNA polymerases of members of the thermoacidophilic branch of the archaebacteria like that of eukaryotic RNA polymerase A of rat liver, is stimulated by the flavonolignane derivative silybin. Eubacterial RNA polymerases are not affected. For both RNA polymerase A of rat liver and RNA polymerase of Thermoplasma acidophilum the stimulatory effect is confined to the enhancement of the elongation reaction suggesting a similar mechanism for both enzymes. These results further support a specific phylogenetic relationships between the archaebacteria and the eukaryotic cytoplasm.
Bovine cardiac troponin subunits: binary complexes and reconstitution of whole troponin
Authors: Byers David M. , Kay Cyril M.
Published: July 2002

The reconstitution of bovine cardiac troponin from its subunits has been investigated using hydrodynamic techniques. Gel filtration (Sephacryl S‐300) and sedimentation velocity experiments indicate that troponin‐C and troponin‐I from a stable binary complex (1:1 mole ratio) with an apparent Stokes' radius of 36 Å (frictional ratio = 1.6). Troponin‐C and troponin‐T do not interact significantly while troponin‐I and troponin‐T undergo partial complex formation. The effect of subunit ratio on the reconstitution of whole troponin has been examined by SDS—polyacrylamide gel electrophoresis and gel filtration and the results suggest that native troponin contains the subunits in an equimolar ratio.
Antigenic cross‐reactivity between electrolectins
Authors: Levi G. , Teichberg V.I.
Published: July 2002

The antigenic cross‐reactivity between purified chick, eel and mouse electrolectins (endogenous β‐D‐galactoside specifc lectins) have been studied using a solid phase radioimmunoassay. The immune serum raised against the eel electrolectin crossreacts both with the chick and the mouse electrolectins, while the anti‐chick electrolectin anti‐serum recognizes only the eel but not the mouse electrolectin. These findings are analyzed in terms of the phylogenetic distance separating the species considered; they suggest that electrolectins fulfil a fundamental biological function.
Inhibition of the T7 DNA polymerase by insulin
Authors: Randahl Håkan
Published: July 2002

T7 DNA polymerase reduced insulin at the same K
m as thioredoxin, while the turnover number decreased. Recycling of the disulfide of thioredoxin subunit to its dithiol form was made by thioredoxin reductase. Incubation of T7 DNA polymerase with insulin decreases its ability to bind DNA and therefore inhibited polymerase and exonuclease activities. Thioredoxin reductase fully reversed this inhibition. Insulin did not induce dissociation of the T7 DNA polymerase subunits, which was tested by immunoadsorbent chromatography. No significant difference in single‐stranded exonuclease compared to polymerase activity was seen in the flow through or the eluate, which had been expected if a dissociation of the subunits had occurred.
[3H]Tetrahydrocerulenin, a specific reagent for radio‐labelling fatty acid synthases and related enzymes
Authors: Roberts Graham , Leadlay Peter F.
Published: July 2002

We have synthesised [3H]tetrahydrocerulenin, a radio‐labelled derivative of cerulenin, an antibiotic from Cephalosporium caerulens which specifically inhibits the condensing enzyme of fatty acid synthases and polyketide synthases from various sources. [3H]Tetrahydrocerulenin binds to fatty acid synthase from pig liver with the same specificity as cerulenin. We have also used [3H]tetrahydrocerulenin to monitor condensing enzyme activity in cell‐free extracts of the erythromycin‐producing organism Streptomyces erythreus.
Reconstitution of stellacyanin as a case of direct Cu(I) transfer between yeast copper thionein and ‘blue’ copper apoprotein
Authors: Hartmann Hans-Jürgen , Morpurgo Laura , Desideri Alessandro , Rotilio Giuseppe , Weser Ulrich
Published: July 2002

It was of interest to examine whether yeast Cu‐thionein could be used to transfer the thiolate bound copper directly into the copper binding site of ‘blue’ apoproteins which contain free thiol groups. In particular apo‐stellacyanin was used in the present study and it was found to be able to accept Cu(I) from yeast Cu‐thionein, without any detectable unspecific Cu(II) intermediate, both aerobically and anaerobically.
Copper is not responsible for the visible fluorescence of blue oxidases
Authors: Avigliano Luciana , Sirianni Patrizia , Morpurgo Laura , Finazzi-Agrò Alessandro
Published: July 2002

The fluorescence of several blue copper proteins upon excitation at 330 nm has been studied. This fluorescence is not related to the redox state or even to the presence of copper, which in some cases can act as a quencher. The intensity of emission seems instead related to the amount of carbohydrate present or to tryptophan photooxidation products.
Biosynthesis of O‐phosphoserine‐containing phosphoproteins by isolated bone cells of mouse calvaria
Authors: Gotoh Y. , Sakamoto M. , Sakamoto S. , Glimcher M.J.
Published: July 2002

Five groups of isolated bone cells from mouse calvaria were incubated with [3H]serine and the presence and amount of O[3H]phosphoserine used as an indication of phosphoprotein synthesis. Cells in the osteoblastic fraction were the most active in synthesizing phosphoproteins, and unlike the other cell groups, released most of the phosphoproteins into the tissue culture medium. When subjected to molecular sieving and ion‐exchange chromatography, the phosphoproteins synthesized by the bone cells of the osteoblastic group behaved like the phosphoproteins extracted from mouse calvaria by EDTA.
Activation of the binding of C1q to immune complexes by zinc
Authors: Easterbrook-Smith S.B.
Published: July 2002

ZnSO4 promotes the binding of C1q to immune complexes over the same concentration range (10−5−10−4 M) that it inhibits binding of C1 to cell‐bound immunoglobulin [Biochem. Biophys. Res. Commun. (1981) 103, 856–862]. At higher concentrations (10−3−2 × 10−2 M) ZnSO4 inhibited the binding of C1q to immune complexes, [K
i = (6 ± 2) × 10−3 M]. This inhibition could be correlated with a ZnSO4‐induced change in the tryptophan fluorescence of C1q [ΔF 25%, K
d = (9.9 ± 1.0) × 10−3 M].
Characterization of a scyllo‐inositol‐containing sialyloligo‐saccharide from normal human urine
Authors: Parkkinen J.
Published: July 2002

Three inositol‐containing sialyloligosaccharides were isolated from normal human urine. Structural studies including gas—liquid chromatography of mono‐ and disaccharide derivatives, methylation analysis, mass spectrometry and glycosidase treatments indicated the structure NeuAc (α2–3)Gal(β1‐0)scyllo‐inositol for one of the oligosaccharides isolated. This provides the first evidence for the natural occurrence of a scyllo‐inositol glycoside in biological material. The two other oligosaccharides isolated were identified as two isomers of NeuAc(α2–3)Gal(β1‐0)myo‐inositol, which have not been identified in normal urine before.
Site—site interaction in the lipid activation of β‐hydroxybutyrate dehydrogenase
Authors: Sandermann H.
Published: July 2002

Kinetic data for the activation of the β‐hydroxybutyrate dehydrogenase by long‐chain lecithins [(1979) Biochemistry 18, 2420–2429; (1983) J. Biol. Chem. 258, 208–214] are analyzed. A previous kinetic model [(1982) Biochemistry 21, 3899–3908] is shown not to apply. Instead, the use of a two‐site Adair equation points to a strongly cooperative interaction between the lecithin binding sites (ΔG, −2.8 kcal/mol).
Detection of two DCCD‐binding components in the envelope membrane of H. halobium
Authors: Konishi Tetsuya , Murakami Naoyuki
Published: July 2002

From labeling studies using [14C]DCCD, the presence of two distinct DCCD‐binding sites was proved in halobacterial membrane, whose binding constants are 0.03 and 0.08 nmol DCCD/mg envelope protein, respectively. HPLC and SDS—PAGE analysis revealed that the radioactivity bound to these sites migrated with apparent molecular masses of 45 and 10.2 kDa protein components, respectively.
Translation of mRNA for human lymphotoxin in microinjected Xenopus oocytes
Authors: Wallach David , Hahn Talia , Budilovsky Sylvia
Published: July 2002

Synthesis and secretion of biologically active human lymphotoxin (LT) can be detected in Xenopus laevis oocytes following their inoculation with poly(A+) RNA from human stimulated peripheral blood lymphocytes, but not in oocytes inoculated with RNA from unstimulated lymphocytes or from fibroblastoid cells. In size‐fractionating mRNA of stimulated lymphocytes most LT activity is found to be coded for by RNA with an approximate sedimentation value of 19 S.
Solid‐phase biosynthesis on high performance thin‐layer plates of blood group glycosphingolipids II
Authors: Samuelsson Bo E.
Published: July 2002

A new method for the study of carbohydrate chain biosynthesis of amphipathic glycosphingolipids is presented. The method takes advantage of the thin‐layer plate which is used as a solid matrix of precursor glycosphingolipids in biosynthetic experiments after chromatographic development of the precursor sample. The method is shown to be simple, fast and sensitive. It minimizes the risk of adding unwanted exogenous precursors and abolishes the need for tedious purification of products after incubation. The method opens up new possibilities for the biosynthetic study of mixtures of glycosphingolipids.
Nonenzymatic glucosylation of proteins: a new and rapid solution for in vitro investigation
Authors: Vaughan Lloyd , Fischer René W. , Zimmermann Dieter R. , Winterhalter Kaspar H.
Published: July 2002

The rates of nonenzymatic glucosylation of albumin, high density lipoprotein (HDL) and low density lipoprotein (LDL) were determined in vitro using [14C]glucose repurified by a new and rapid HPLC method. All commercial preparations were found to contain contaminants reacting 15–20‐times faster with protein than the repurified [14C]glucose. Removal of contaminants was critical to the rate determinations and constitutes a substantial improvement over the widely used existing method. The initial rates of nonenzymatic glucosylation determined in vitro for albumin, HDL and LDL were used to predict normal in vivo levels of 0.40, 0.65 and 0.08 mol glucose per mol protein, respectively. This is within the range of values found in vivo for albumin and LDL, but low for HDL. These values would be expected to increase 2–4‐fold in diabetes.
In vitro methylation of total and foldback DNAs in normal and virus‐transformed cells
Authors: Voipe Pietro , Eremenko Tamilla
Published: July 2002

The levels of the in vitro methylation of total and palindromic DNAs in nuclei isolated from normal and virus‐transformed cells are compared. The methylation rate of total DNA in normal rat kidney cells is much higher than that detected in normal mouse fibroblasts. However, for both cell species, while the maximal rate of DNA methylation is observed in the mid‐logarithmic phase of the cell culture growth, palindromes are always found to be more heavily methylated than total DNA. The 5‐methylcytosine content of DNA, especially of palindromes, is higher in virus‐transformed cells than in untransformed cells.
Effects of vanadate on intracellular Ca2+ redistribution and hexose transport across plasma membrane in cultured mouse fibroblasts
Authors: Yamanishi Kiyofumi , Hasegawa Teiko , Iwashima Akio
Published: July 2002

The effects of vanadate on intracellular Ca2+ sequestration and hexose transport were studied in Swiss 3T3 cells. Vanadate inhibited ATP‐dependent Ca2+ uptake by saponin‐permeabilized Swiss 3T3 cells at 10−5 and 10−7M Ca2+ at which the Ca2+ uptake was sensitive and insensitive to oligomycin plus antimycin A, respectively. On the other hand, vanadate stimulated 2‐deoxy‐D‐glucose (2DG) uptake in a dose‐ and time‐dependent way. The stimulation of 2DG uptake by vanadate was inhibited by EGTA plus A23187 and the inhibition was reversed by Ca2+ restoration. These results suggest that an increase in cytosolic Ca2+ by inhibition of intracellular ATP‐dependent Ca2+ sequestration by vanadate results in the stimulation of hexose transport in Swiss 3T3 cells.
Effect of streptomycin on the stoichiometry of GTP hydrolysis in a poly(U)‐dependent cell‐free translation system
Authors: Smailov S.K. , Gavrilova L.P.
Published: July 2002

The technique of Sepharose‐bound template translation has been used to estimate the stoichiometry of GTP hydrolysis during peptide elongation in the presence of streptomycin. The presence of streptomycin has been shown to have no great effect on the elongation rate and the stoichiometry of GTP hydrolysis during codonspecific peptide elongation in the poly(U)‐directed translation system: the molar ratio of hydrolysed GTP to incorporated phenylalanine was about 2. At the same time streptomycin exerted a significant effect during misreading when a ribosome‐bound peptide in the poly(U)‐programmed system was elongated by leucine or isoleucine residues: the miselongation was stimulated and hence the ratio of hydrolysed GTP per peptide bond was strongly reduced, as compared with the excessive GTP hydrolysis which is characteristic of the misreading system in the absence of streptomycin [(1984) FEBS Lett. 178, 283‐287]. The conclusion has been made that streptomycin blocks the stage of correction (‘proof‐reading’) following GTP hydrolysis during EF‐Tu‐dependent aminoacyl‐tRNA binding.
Catalytic activity of the membrane‐bound methylcholanthrene‐inducible cytochrome P‐450
Authors: Grishanova A.Yu. , Mishin V.M. , Lyakhovich V.V.
Published: July 2002

The benzopyrene hydroxylase activity of the methylcholanthrene‐inducible form of cytochrome P‐450 (P‐448) has been studied in native and reconstituted liver microsomal membranes. The data obtained show that the molecular catalytic activity of membrane‐bound cytochrome P‐448 depends on the molar ratio of the cytochrome to NADPH‐cytochrome P‐450 reductase and that the optimal ratio for maximal activity of cytochrome P‐448 in the microsomal membrane essentially differs from the equimolar one.
A → Z transition in the synthetic hexanucleotide (dCdGfl)3
Authors: Fazakerley G.V. , Uesugi S. , Izumi A. , Ikehara M. , Guschlbauer W.
Published: July 2002

500 MHz proton NMR and NOE measurements on (dCdGfl)3 show that at very low ionic strength the hexanucleotide adopts an A‐DNA conformation, whereas at high salt concentrations a Z‐form is found. At intermediate salt concentrations the two species are in slow exchange on the proton NMR time scale. This transition was also observed by characteristic changes in the CD spectra.
X‐ray characterisation of an additional binding site in lysozyme
Authors: Veerapandian B. , Salunke D.M. , Vijayan M.
Published: July 2002

Bromophenol red (BPR) binds to lysozyme and inhibits its activity against bacterial cell walls, but not against the polysaccharide component of peptidoglycan. The binding site of BPR in the enzyme has been characterised by X‐ray analysis of the complex at 5.5Å resolution. The new binding site, which is outside the cleft close to subsite F, is presumably involved in interactions with the peptide component of peptidoglycan, in the action of lysozyme against bacterial cell walls.
The chromone inhibitor stigmatellin ‐ binding to the ubiquinol oxidation center at the C‐side of the mitochondrial membrane
Authors: von Jagow G. , Ohnishi Tomoko
Published: July 2002

Cytochrome bc2
complex
Inhibitor
Fe2S2 protein
EPR
Cytochrome b Stigmatellin
Nutrient insulin secretagogues decrease 45Ca2+ efflux from islet cells by a mechanism other than the inhibition of the Na+‐Ca2+ countertransport
Authors: Henquin J.C. , de Miguel R. , Garrino M.G. , Hermans M. , Nenquin M.
Published: July 2002

The mechanism whereby nutrient insulin secretagogues decrease 45Ca2+ efflux from islet cells is controversial. It was studied with mouse islets perifused with Ca2+‐free solutions. In the presence of Na+, glucose and ketoisocaproate inhibited 45Ca2+ efflux by about 50%. Substitution of choline+ salts for Na+ salts decreased the efflux rate by 45%, but did not prevent glucose from decreasing it further. Ketoisocaproate also inhibited 45Ca2+ efflux, but less markedly than in an Na+ medium. Omission of Na+ decreased the efflux rate even when it was already lowered by glucose or ketoisocaproate. It is thus clear that nutrient insulin secretagogues decrease 45Ca2+ efflux from islet cells by a mechanism other than the inhibition of the Na+‐Ca2+ countertransport, possibly by increasing sequestration of the ion in cellular organelles.
Selected positions of acyl chains are affected differently by antibody binding which results in decreased membrane fluidity
Authors: Hart Matthew J. , Kimura Kazuko , Nakanishi Mamoru
Published: July 2002

Membrane fluidity
Stopped‐flow
Liposome
Antibody Lipid hapten
Excimer fluorescence
Protease gene structure and env gene variability of the AIDS virus
Authors: Yasunaga Teruo , Sagata Noriyuki , Ikawa Yoji
Published: July 2002

The protease gene structure and the env gene variability have been precisely compared between the AIDS virus and members of the HTLV/BLV family. The conserved amino acid sequence (LVDT) which is repeated in the proteases of the HTLV/BLV family is not repeated in AIDS virus. Comparative analysis of the env gene sequences reveals the striking fact that the env gene of AIDS virus is 8–12‐times more variable than those of the HTLV/BLV family. Within the AIDS virus env gene, the surface glycoprotein region is more liable to vary than is the transmembrane region; unexpectedly, however, this liability is not a characteristic feature of the AIDS virus because it is more prominent in other retroviruses including members of the HTLV/BLV family.
Identification of creatine as a cofactor of thiamin‐diphosphate kinase
Authors: Shikata Hiroo , Koyama Shin-ya , Egi Yoshiko , Yamada Kazuo , Kawasaki Takashi
Published: July 2002

Thiamin‐diphosphate (TDP) kinase which catalyzes thiamin triphosphate formation from TDP requires a low‐molecular‐mass cofactor in addition to ATP and Mg2+. The cofactor was isolated in a crystalline form from pig skeletal muscle and identified as creatine by proton NMR, mass spectrometry, infrared spectrometry and elemental analysis. The isolated cofactor and authentic creatine supported the same activity of partially purified TDP kinase at identical molar concentrations. Neither creatine phosphate nor creatinine showed activity as a cofactor. This is the first report showing evidence of the existence of a creatine‐dependent enzyme.
Redox properties of the flavoprotein of methane monooxygenase
Authors: Prince Roger C. , Patel Ramesh N.
Published: July 2002

The redox properties of the flavin and iron‐sulfur cluster of the flavoprotein of methane monooxygenase from Methanobacterium CRL26 have been determined. The Em7
of the flavin/protonated semiquinone = − 195 mV, that of the protonated semiquinone/fully reduced form = − 250 mV, and that of the Fe2S2 center = − 247 mV. This suggests that the protein cycles between the fully reduced form and the flavin semiquinone form as it shuttles electrons from NADH to the methane hydroxylase.
A novel 15 kDa Ca2+‐binding protein present in the eggs of the sea urchin, Hemicentrotus pulcherrimus
Authors: Hosoya Hiroshi , Iwasa Fuyuki , Ohnuma Masaaki , Mabuchi Issei , Mohri Hideo , Sakai Hikoichi , Hiramoto Yukio
Published: July 2002

A novel Ca2+‐binding protein, different from calmodulin, has been purified to homogeneity from the soluble cytoplasmic protein fraction of the egg of the sea urchin, Hemicentrotus pulcherrimus. This protein, designated as 15 kDa protein, shows a Ca2+‐dependent mobility shift upon SDS‐gel electrophoresis and has Ca2+‐binding ability. This protein did not resemble the sea urchin egg calmodulin in either molecular mass or amino acid composition. The 15 kDa protein could not activate cyclic adenosine 3',5'‐monophosphate‐dependent phosphodiesterase from bovine brain and did not bind to fluphenazine‐Sepharose 6B. Antibodies against the 15 kDa protein did not react with sea urchin egg calmodulin. These results suggest that the 15 kDa protein is a novel Ca2+‐binding protein in the sea urchin egg.
Mechanism of UDP‐sugar transport into intracellular vesicles
Authors: Cecchelli Roméo , Cacan René , Verbert André
Published: July 2002

The mechanism of translocation of UDP‐GlcNAc, UDP‐Gal and UDP‐Glc into intracellular vesicles has been studied using thymocytes whose plasma membranes have been permeabilized with isotonic ammonium chloride. It has been previously shown that the intracellular vesicles have specific carriers for UDP‐GlcNAc and UDP‐Gal. We now report that the translocation of these two sugar nucleotides occurs via UDP‐GlcNAc/UDP and UDP‐Gal/UDP antiports. The entry of UDP‐GlcNAc or UDP‐Gal into vesicles was specifically dependent on the exit of UDP from these vesicles. In contrast, no antiport mechanism has been recovered with UDP‐Glc for which no transport and accumulation into intracellular vesicles were observed.
A new intermediate in the photocycle of bacteriorhodopsin
Authors: Dancshazy Zsolt , Govindjee Rajni , Nelson Burr , Ebrey Thomas G.
Published: July 2002

With increasing pH (6.0 to 10.5) there is an increasing discrepancy between the recovery rate of bacteriorhodopsin after a flash and the decay rates of the key photointermediates, Mfast and Mslow, which is not predicted by any model of the photocycle. However, a very slowly decaying absorbance change at 350 nm has kinetics which match the very slow part of the recovery of bacteriorhodopsin, suggesting a new intermediate. The difference spectra of the bacteriorhodopsin photocycle measured at pH 10.5, obtained from fitting 3 exponentials to the flash‐induced absorbance changes in the 300–560 nm wavelength range, show maxima, at 410–420 nm corresponding to the 2 forms of M and at 350 nm corresponding to the new intermediate. We propose to call this new species R350.
Activation of chicken liver fructose‐1,6‐bisphosphatase by oxidized glutathione
Authors: Han Peter , Hang David , Emmett Nerimiah , Han Grace , Johnson Joe
Published: July 2002

Treatment of chicken liver fructose‐1,6‐bisphosphatase with oxidized glutathione (GSSG) leads to an increase in activity. This activation is markedly enhanced if treatment is performed in the presence of AMP or Mn2+. The effects of AMP and Mn2+ appear to be synergistic. The maximal activation is over 13‐fold and is accompanied by the disappearance of 4 sulfhydryl groups per molecule of enzyme. Both fructose 1,6‐bisphosphate and fructose 2,6‐bisphosphate can largely prevent this activation. Activation can be reversed by dithiothreitol or cysteine. It appears that GSSG activates this enzyme by thiol/disulfide exchanges with the enzyme's specific sulfhydryl groups.
Red blood cell targeting to smooth muscle cells
Authors: Glukhova Marina A. , Domogatsky Sergey P. , Kabakov Alexander E. , Muzykantov Vladimir R. , Ornatsky Olga I. , Sakharov Dmitry V. , Frid Maria G. , Smirnov Vladimir N.
Published: July 2002

Monoclonal antibody discriminating between endothelial and smooth muscle cells is suggested to be used as a vector for directed transport of drugs to injured (denuded) areas of blood vessel wall. An in vitro model system was used in the studies: vascular smooth muscle or endothelial cells grown on plastic surface were treated with specific mouse monoclonal antibody recognizing an antigen localized on the surface of smooth muscle rather than endothelial cells; then erythrocytes coated with secondary (rabbit antimouse) antibodies were added. The results were analyzed spectrophotometrically or with scanning electron microscopy. Under the experimental conditions, erythrocytes, possible ‘containers’ for carrying the drugs, were found to bind only to smooth muscle cells. The data show that antibody provides absolute discrimination between endothelial and smooth muscle cells and, thus, may be used as a vector for drug targeting.
X‐ray absorption studies on bacteriorhodopsin
Authors: Engelhard M. , Hess B. , Chance M. , Chance B.
Published: July 2002

Extended X‐ray absorption (EXAFS) measurements of iron‐substituted bacteriorhodopsin revealed for the light‐adapted state (bRLA) a homogeneous distribution of the first‐shell ligands of iron. In Contrary to this result, the dark‐adapted (bRDA) and the M‐state (bRM) display significant heterogeneity at the iron site with bRDA intermediate between bRM and bRLA in average distance. These data provide direct evidence of structural changes at the membrane associated with photocycle changes at the cation‐binding site.
Insect immunity: cDNA clones coding for the precursor forms of cecropins A and D, antibacterial proteins from Hyalophora cecropia
Authors: Lidholm Dan-Anders , Gudmundsson Gudmundur H. , Xanthopoulos Kleanthis G. , Boman Hans G.
Published: July 2002

Using synthetic probes cDNA clones were isolated correponding to the precursor forms of cecropins A and D. The sequences obtained were compared to earlier data for preprocecropin B. A processing scheme in three or four steps is discussed.
A new carbene based heterobifunctional reagent Photochemical crosslinking of aldolase
Authors: Mogre R.M. , Batliwala H.F. , Anjaneyulu P.S.R. , Lala A.K.
Published: July 2002

The synthesis of a new photoactivatable heterobifunctional crosslinking reagent, the N‐oxysuccinimide ester of 2‐carboxy‐9‐diazofluorene, is described. The ability of the parent chromophore 2‐carbomethoxy‐9‐diazofluorene to insert into cyclohexane and methanol has been established. The reagent has been linked to aldolase and the stoichiometry determined. Photolysis of the probe‐linked aldolase indicated that photolysis was very rapid and that the photolysed product was constituted of crosslinked dimer, trimer and tetramer. Increase in concentration of probe linked to aldolase followed by photolysis gave rise to largely tetramer and higher oligomers of aldolase. The use of this carbene‐based reagent vis a vis arylazide‐based reagent for studying protein crosslinking is discussed.
Interaction of synthetic analogs of distamycin with DNA
Authors: Parrack Pradipkumar , Dasgupta Dipak , Ayyer Jayalekshmy , Sasisekharan V.
Published: July 2002

Interaction of two synthetic analogs of distamycin (Dst), PPA and PAP, containing a saturated β‐alanine moiety replacing one N‐methylpyrrole ring, with different polynucleotides and natural DNAs were studied using UV and CD spectroscopy. The results indicate that, similar to Dst, these analogs bind to DNA via the minor groove with a specificity towards AT‐base pairs. It may be proposed that pyrrole chromophores in Dst probably do not play a role in the AT‐base selectivity exhibited by Dst.
tRNA specificity of a mischarging aminoacyl‐tRNA synthetase: Glutamyl‐tRNA synthetase from barley chloroplasts
Authors: Schön Astrid , Söll Dieter
Published: July 2002

Glutamyl‐tRNA synthetase (GluRS) from barley chloroplasts is a naturally occurring mischarging enzyme: it efficiently aminoacylates both the homologous tRNAGlu as well as tRNAGln species. In order to shed light on the structural requirements of this enzyme for tRNA specificity heterologous charging experiments were performed. Sequence comparison of tRNAs recognized by barley chloroplast GluRS reveals that two base pairs, one in the acceptor stem and one in the anticodon stem, appear to be critical for substrate recognition.
Studies on the import into mitochondria of yeast ATP synthase subunits 8 and 9 encoded by artificial nuclear genes
Authors: Law Ruby H.P. , Farrell Leigh B. , Nero Debra , Devenish Rodney J. , Nagley Phillip
Published: July 2002

Direct fusions have been constructed between each of subunits 8 and 9 from mitochondrial ATPase of Saccharomyces cerevisiae, proteins normally encoded inside mitochondria, and the cleavable N‐terminal transit peptide from the nuclearly encoded precursor to subunit 9 of Neurospora crassa mitochondrial ATPase. The subunit 8 construct was imported efficiently into isolated yeast mitochondria and was processed at or very near the fusion point. When expressed in vivo from its artificial nuclear gene, this cytoplasmically synthesized form of subunit 8 restored the growth defects of aap1 mutants unable to produce subunit 8 inside the mitochondria. The subunit 9 construct was, however, unable to be imported into isolated mitochondria and could not, following nuclear expression in vivo, complement growth defects in mitochondrial oli1 mutants. This behaviour is contrasted with the previously demonstrated import competence of another yeast subunit 9 fusion, bearing the first five residues of mature N. crassa subunit 9 interposed between its own transit peptide and the yeast subunit 9 moiety.
Identification of two fixation sites for penicilloyl groups on the albumin molecule from penicillin‐treated patients
Authors: Lafaye Pierre , Lapresle Claude
Published: July 2002

Fixation of penicilloyl groups to albumin in penicillin‐treated patients was shown to involve histidine residues 146 and 338.
Hydrogen exchange from the transbilayer hydrophobic peptide of glycophorin reconstituted in lipid bilayers
Authors: Sami Malkit , Dempsey Christopher
Published: July 2002

The hydrophobic transbilayer peptide of erythrocyte glycophorin has been purified following exchange of tritium into the backbone amides, and reconstituted in egg phosphatidylcholine micelles. Analysis of tritium exchange from the backbone amides of the membrane‐reconstituted peptide shows that about two of the amides are virtually non‐exchangeable, about 10 are slowed by factors of 107 relative to free amides in unstructured water soluble peptides and the remainder of the amides (about 20) have slowing factors of less than 1000. These classes of amides are proposed to reflect the stability of the peptide with respect to hydrogen bond breaking fluctuations and the accessibility of the amides to exchange catalysts in different regions of the bilayer.
Mesenteric vascular responses to i.v. administration of lipoxin A4 and lipoxin B4 in the conscious rat
Authors: Feuerstein Giora , Siren Anna-Leena
Published: July 2002

Lipoxin A4 and lipoxin B4 are newly discovered lipoxygenase‐interacting products of leukocytes which might have a role in cardiovascular events associated with anaphylaxis. We have tested this possibility by systemic administration of both LXA4 and LXB4 to the conscious rat while monitoring systemic and regional hemodynamic changes. LXA4 and LXB4 (1–100 μg/kg) produced dose‐dependent constriction of the mesenteric vessels, up to + 123 ± 23% and + 50 ± 9% for LXA4/B4, respectively. Dose‐related changes were not observed in arterial blood pressure, heart rate, renal (LXB4) and hindquarter blood flow. We suggest that LXA4 and LXB4 might affect selective vascular beds, such as the mesenteric vessels, and contribute to variations in blood flow in specific pathophysiological states.
Strand‐specific transcription of the simple sequences poly[(dG‐dT):(dC‐dA)] and poly[(dG‐dA):(dC‐dT)] in D. melanogaster embryos revealed by S1 nuclease treatment
Authors: Vashakidze R.P. , Mamulashvili N.A. , Kalandarishvili K.G. , Kolchinsky A.M.
Published: July 2002

The transcription of different strands of the simple sequences poly[(dG‐dT):(dC‐dA)] and poly[(dG‐dA):(dT‐dC)] in Drosophila melanogaster embryos was studied. After selective labelling of one strand, the polymers were hybridized with immobilized RNA and hybrids were treated on filters with S1 nuclease. Appropriate control has shown that this treatment destroys sandwich‐like complexes and leaves only true hybrids. Transcription of poly[(dG‐dA):(dT‐dC)] proved to be nearly symmetric, while poly(dG‐dT) is transcribed 3‐times more intensively than poly(dA‐dC). Our approach allowed us to estimate the relative content of simple sequences in RNA.
Bacillus thuringiensis ssp. galleriae simultaneously produces two δ‐endotoxins differing strongly in primary structure and entomocidal activity
Authors: Chestukhina G.G. , Kostina L.I. , Zalunin I.A. , Khodova O.M. , Stepanov V.M.
Published: July 2002

Strain 11–67 of B. thuringiensis ssp. galleriae produces two entomocidal proteins of molecular mass 130 kDa. Limited proteolysis of these proteins — protoxins — yields the ‘true’ toxins of molecular mass 65 kDa which are drastically different with respect to their charges at pH 8.6, immunological properties and toxicity (host range). One of the proteins — the ‘negative’ component — is toxic for Lymantria dispar larvae and shows 65% homology when compared with B. thuringiensis ssp. kurstaki δ‐endotoxins. The other — the ‘positive’ component — is toxic for Galleria mellonella larvae. Its N‐terminal sequence of 11 amino acid residues is homologous with the B. thuringiensis ssp. israelensis and san diego endotoxins known to be toxic for Coleoptera and Diptera but not for Lepidoptera. Hence, B. thuringiensis subspecies may produce simultaneously δ‐endotoxins differing substantially in structural features and host range.
Dual effect of the phorbol ester TPA on arachidonic acid release from HeLa cells
Authors: Kaszkin M. , Espe U. , Fu¨rstenberger G. , Kinzel V.
Published: July 2002

The tumor promoter 12‐O‐tetradecanoylphorbol 13‐acetate (TPA) induces release of arachidonic acid (AA) from HeLa cells with a maximum at 2–3 h. Subsequently the extracellular level of AA decreases. Cycloheximide (CH, 10−5 M) does not influence the release of AA, however, it causes the AA level to remain elevated. In the presence of TPA and CH (i) re‐uptake of AA is not altered, (ii) re‐incorporation of AA into phosphatidylinositol (and phosphatidylethanolamine) is largely increased, and (iii) the level of lysophosphatidylinositol is elevated. The latter two phenomena can be prevented by fluocinolone acetonide (10−8 M), i.e. by inhibition of phospholipase A2 (PLA2). These data point to a continuously elevated PLA2 activity in the presence of TPA and CH. The phorbol ester appears to induce a proteinaceous principle which diminishes PLA2 activity.
Detection of anion‐linked polymerization of the tetrameric hemoglobin from Scapharca inaequivalvis by 31Cl NMR spectroscopy
Authors: Chiancone Emilia , Drakenberg Torbjo¨rn , Forse´n Sture
Published: July 2002

Ion binding to the hemoglobin components of Scapharca inaequivalvis has been measured directly in quadrupole relaxation experiments of 23Na and 35Cl. The dimeric and tetrameric hemoglobins interact weakly with sodium ions, but differ in their interaction with chloride ions. The dimeric hemoglobin binds chloride ions with low affinity, whereas the tetrameric protein has high‐affinity chloride binding sites. Binding of chloride ions to these high‐affinity sites brings about an oxygen‐linked polymerization which manifests itself in an unusual dependence of the 35Cl excess linewidth on the concentration of the anion. Polymerization is more pronounced in the deoxygenated than in the oxygenated derivative: in the former, it has been observed previously in sedimentation velocity experiments. The sensitivity of the 35Cl excess linewidth on polymer formation indicates that the residence time of the transiently bound chloride on the tetrameric hemoglobin is not shorter than the correlation time of the molecule (2 × 10−1 s−1).