bluuebunny/crossref_metadata_2025 huggingface dataset:
Role of Self-help Groups (SHGs) in Enhancing Incomes of Rural Women in J&K, India
Authors: Ahemad Shamim , Katoch Om Raj
Published: October 2022

Women are the most vulnerable section of our society and their agony in Jammu and Kashmir is more intensified during the last three decades due to prevailing militancy. They work round the clock but lack decision making powers in household affairs as well as in the society. The central and state government has launched several schemes for women empowerment and National Rural Livelihood Mission is one among them. Under this self-employment scheme, the rural women are organized in Self Help Groups (SHGs) and are provided funds for their upliftment. To understand the success in the performance of Jammu & Kashmir Rural Livelihood Mission (JKSRLM) in terms of enhancing income of the women, a total of 80 beneficiaries selected through multi-stage sampling were interviewed by giving equal weightage to two districts of Doda and Jammu respectively. The results reflected that SHGs have played a significant role in the life of rural women in terms of enhancing income and employment. The JKSRLM is a great tool for concerted efforts to improve the economic conditions of the people, and the importance of education must not be overstated, since it influences the choices women and girls make about employment and income generation increasingly.
Cell adhesion activity of the short cytoplasmic domain isoform of C‐CAM (C‐CAM2) in CHO cells
Authors: Olsson Helena , Wikström Kristina , Kjellström Gunilla , Öbrink Björn
Published: July 2002

C‐CAM is a Ca2+‐independent rat cell adhesion molecule belonging to the CEA gene family of the immunoglobulin superfamily. Two major isoforms that differ in the length of their cytoplasmic domains exist. In previous studies it has been reported that only the long isoform (C‐CAM1) but not the short isoform (C‐CAM2) can mediate adhesion. However, in the mouse, isoforms with both long and short cytoplasmic domains have been reported to have adhesive activity. In order to analyze this apparent conflict we transfected C‐CAM1 or C‐CAM2 into CHO Pro5 cells and examined their adhesive phenotype in an aggregation assay. We found that in this cellular system both C‐CAM1 and C‐CAM2 could mediate cell‐cell adhesion in a Ca2+‐independent and temperature‐independent way. The results suggest that the cellular environment is important for the activity of C‐CAM isoforms.
Functional and structural recovery of myotubes from mice with muscular dysgenesis after co‐culture with normal, non‐myoblastic cells
Authors: Dussartre Christian , Borrelli Donatella , Duvert Michel , Melone Marina , Koenig Jeanine
Published: July 2002

Summary— Muscular dysgenesis is a mutation which is characterized by paralysis of skeletal muscle cells. Excitation‐contraction coupling is deficient and muscle cells display atypical ultrastructure. In vitro, mutant myotubes recover a normal phenotype when cocultured with spinal cord cells from normal animals or with normal fibroblasts. We have shown that other types of cells, eg certain glial cells present in the spinal cord or in other tissues, have this capacity. In contrast, intervention of neurons in the recovery does not appear likely. Very different types of non‐myoblastic cells, then, are capable of restoring contractile activity of dysgenic myotubes in vitro, suggesting that a non‐specific mechanism is involved in the phenotypic reversion of affected muscle cells. The restoration process seems to imply a close relationship between myotubes and normal glial cells.
Relationship between the acid phosphatases of the Kurloff body and the major 30–35 kDa glycoproteins of the Kurloff cell
Authors: Oulhaj Nourdine , Taouji Saïd , Izard Jacques , Landemore Gérard
Published: July 2002

Summary— This study deals with the acid phosphatase (AcPase) of the Kurloff body (KB), a large (10 μm diameter) periodic acid‐Schiff‐positive lysosomal inclusion body present in Kurloff cells (KC). KC AcPase were extracted, with similar yields, either with non‐ionic detergent solution or after Dounce homogenization in low ionic strength buffer suggesting that they mainly correspond to hydrosoluble AcPase. After DEAE‐cellulose chromatography of such crude Dounce‐extracts, 97% of KC AcPase activity was recovered in the unbound glycoprotein fraction (peak I). The main protein content consisted of, as testified by SDS‐PAGE analysis, major KC glycoproteins of 30–35 kDa. Thus, KC AcPase, and particularly sialoAcPase, may be assumed to correspond to these N‐glycosylproteins among which the presence of α (2,6) sialoglycoproteins was previously established. Following electrophoresis on a 4–15% gradient native polyacrylamide gel or isoelectric focusing, the two size populations (200 kDa and 500 kDa) and up to 20 isoforms of KC AcPase were respectively detected by zymography in peak I. After Clostridium‐derived sialidase digestion of peak I, the highly active bands observed at pH 3.5 −5.2 disappeared. These zymographic patterns were similar to those obtained with crude extracts. After Concanavalin A (ConA)‐Sepharose chromatography of peak I, the single ConA‐bound glucosamine‐labelled peak, eluted at 200 methyl‐α‐d‐mannopyranose, contained the AcPase activity while the ConA‐unbound peak was devoid of any acid phosphatase activity. After SDS‐PAGE analysis, the ConA‐bound fraction appeared to correspond only to a single broad protein band in the 30–35 kDa zone. The Sambucus nigra agglutinin‐reactivity of the latter band confirmed the α (2,6) sialylation pattern of KC AcPase. Moreover, their strong binding to ConA‐Sepharose suggests that they could only correspond to the hybrid type of the N‐glycosylproteins, since they could not correspond to the oligomannosidic type considering the absence of Galanthus nivalis agglutinin‐positive structures.
RGD‐mediated adhesion of porcine granulosa cells modulates their differentiation response to FSH in vitro
Authors: Goxe Béatrice , Flechon Jacques E. , Delasalle Solange , Salesse Roland
Published: July 2002

Summary— Porcine granulosa cells cultured in serum‐free medium undergo metabolic and morphologic changes after follicle stimulating hormone (FSH) stimulation. Under these conditions, granulosa cells differentiate and tend to round up and their links with the plastic support are reduced. Coating of culture substratum with PepTite‐2000, an integrin‐binding synthetic peptide containing RGD (Arg‐Gly‐Asp) sequences enhanced the plating of granulosa cells. Whether the peptide be present or not, cells cultivated in basal synthetic medium (without FSH) were flattened and attached to the substratum by stress fibers at focal contacts where integrin β1, extracellular fibronectin, and urokinase plasminogen activator colocalized. After FSH stimulation, part of the cells rounded up and F‐actin took a more uniform, cortical localization. Correlatively, extracellular fibronectin aggregated in a clump, while integrin β1 and urokinase plasminogen activator spread over rounded cells. These morphological changes elicited by FSH were little affected by the presence of PepTite‐2000, yet a larger number of cells remained flattened. However, concerning steroidogenesis, increasing concentrations of peptide seemed to favor progesterone rather than estrogen production, and to restrain luteinizing hormone (LH) receptor expression, suggesting a premature committment of cells towards luteinization rather than completion of follicular preovulatory differentiation.
The replication band of Euplotes is DNase I sensitive
Authors: Olins Donald E.
Published: July 2002

Summary— Employing in situ nick translation on isolated macronuclei from the ciliate Euplotes eurystomus, the replication band exhibited heightened DNase I sensitivity. This enhanced reactivity was not significantly affected by decreased replication induced with heat shock or added inhibitors, implying that the underlying chromatin modulations are reasonably stable. The nuclease sensitivity of the replication band is probably related to the ‘maturation’ of nascent chromatin, since transcriptional activity is known to be absent within the band. An additional observation of this study was the in vivo incorporation of halogen‐deoxynucleosides into replication bands, facilitating future studies of matrix‐associated nascent DNA.
Transfected Saos‐2 cells overexpressing phosphoinositidase Cβ1 isoform accumulate it within the nucleus
Authors: Marmiroli Sandra , Zini Nicoletta , Bavelloni Alberto , Faenza Irene , Ognibene Andrea , Maraldi Nadir M
Published: July 2002

Summry— The subcellular partitioning of the phosphoinositidase C (PIC) isoforms involved in signal transduction, with the selective localization of the PIC β1 isoform in the nucleus, represents a crucial aspect of the complex mechanism of cell response to agonists. In order to further elucidate this phenomenon, we utilized human osteosarcoma Saos‐2 cells, transfected with the cDNA for rat PIC β1. In the cells overexpressing this isoform, immunocytochemical analyses at the electron microscope level reveal an increased synthesis at the cytoplasm and a significant accumulation within the nucleus of the protein. Interestingly, the sites of intranuclear localization are, as in wild type cells, the interchromatin domains. These results indicate that the transfected cells maintain the capability of accumulating the enzyme within the nucleus and can be considered a model for functional studies on the nuclear signal transduction also in response to specific agonists.
A deep‐etch study of the cytoskeleton of Giardia duodenalis
Authors: Kattenbach William M , Diniz Jose AP , Benchimol Marlene , de Souza Wanderley
Published: July 2002

Summry— The quick‐freeze, freeze‐fracture, deep‐etching and rotary replication techniques were used to analyze the structural organization of Giardia duodenalis. The surface of the flagella was rugous, in contrast to the cell body surface which was smooth. The ventral region was characterized in more detail, exposing the layer of sub‐pellicular microtubules bonded to the microribbon sheet which appears as an open flat helicoid structure where the two free ends overlap and adhere close to the frontal part of the protozoan. The microribbon appears as 18‐nm thick parallel (35 nm interval) filaments connected by short bridges. A flattened structure with a highly organized array of particles was seen close to the microribbons.
Cloning of a mouse glucocorticoid modulatory element binding protein, a new member of the KDWK family
Authors: Jimenez-Lara Ana M. , Heine Mattias J.S. , Gronemeyer Hinrich
Published: July 2002

A mouse cDNA that encodes a nuclear DNA binding protein was identified by yeast two‐hybrid screening using the activation domain 2 of the nuclear receptor coactivator TIF2 as a bait. BLAST analysis revealed that the identified cDNA encodes a KDWK domain and contains sequences almost identical to three tryptic peptides of rat GMEB‐1 which together with the GMEB‐2 heterodimeric partner binds to the GME/CRE sequence (glucocorticoid modulatory element) of the tyrosine aminotransferase (TAT) promoter. Mouse GMEB‐1 is ubiquitously expressed in all the tissues examined. In vitro translated mGMEB‐1 bound specifically to GME oligonucleotides, either alone or as a heterodimer with rGMEB‐2. Transient transfection experiments with TAT promoter reporter genes suggest a potential role for mGMEB‐1 as a transcriptional regulator of the TAT promoter.
Silefrin, a sodefrin‐like pheromone in the abdominal gland of the sword‐tailed newt, Cynops ensicauda
Authors: Yamamoto Kazutoshi , Kawai Yuka , Hayashi Tomoko , Ohe Yoshihide , Hayashi Hiroaki , Toyoda Fumiyo , Kawahara Genri , Iwata Takeo , Kikuyama Sakaé
Published: July 2002

Sodefrin‐like female‐attracting pheromone was purified from the abdominal glands of male sword‐tailed newts, Cynops ensicauda, by gel‐filtration chromatography and reversed‐phase high‐performance liquid chromatography. The final product comprises 10 amino acid residues with the sequence SILSKDAQLK which coincided with the sequence deduced from its precursor cDNA. This peptide was designated silefrin. The sequence of silefrin was different from that of sodefrin by two amino acid residues, with substitutions Leu for Pro and Gln for Leu at positions 3 and 8, respectively. Both native and synthetic silefrin exerted an equipotent activity in attracting conspecific females.
Caloric restriction prevents oxidative damage induced by the carcinogen clofibrate in mouse liver
Authors: Qu Bin , Halliwell Barry , Ong Choon Nam , Lee Bee Lan , Li Qiu-Tian
Published: July 2002

Long‐term caloric restriction in rodents is known to decrease levels of oxidative damage, which may contribute to an ‘anti‐ageing’ effect. We show here that a shorter period (10 months) of caloric restriction had only small effects on levels of oxidative DNA and protein damage in the livers of mice, but completely attenuated increased oxidative damage caused by the carcinogen clofibrate. Since clofibrate is thought to exert its actions by increasing oxidative damage, our data suggest that 10 months of caloric restriction can increase the resistance of tissues to agents inducing oxidative stress. This may be an important factor in explaining how caloric restriction decreases cancer incidence.
Identification of alternative splicing variants of the β subunit of human Ca2+/calmodulin‐dependent protein kinase II with different activities
Authors: Wang Ping , Wu Ya-Lan , Zhou Tian-Hua , Sun Yue , Pei Gang
Published: July 2002

The β subunit of human Ca2+/calmodulin‐dependent protein kinase II (β CaMKII) was identified by searching through an expressed sequence tag database and rapid amplification of cDNA 5′‐ends and was assigned to chromosome 7. Reverse transcription‐polymerase chain reaction and sequencing analysis identified at least five alternative splicing variants of β CaMKII (β, β6, βe, β′e, and β7) in brain and two of them (β6 and β7) were first detected in any species. When expressed in HEK 293 cells, the Ca2+/calmodulin‐dependent kinase activity of β7, the shortest variant, was much lower than that of either β (the longest one) or βe (the medium one), suggesting possible regulation of β CaMKII activity by alternative splicing.
Reduction of cell density dependent antigenic properties of intracellular Ca2+‐regulating membranes by isoflurane in human endothelial cells
Authors: Petzelt Christian , Stein Jörg , Hermoso Francisco , Kox Wolfgan J.
Published: July 2002

An established cell line of human umbilical vein endothelial cells displays a pronounced shift in the distribution of intracellular Ca2+‐regulating membranes as the cells grow towards confluence. In sparsely populated cultures a linearly oriented punctate pattern of vesicle‐like structures is observed similar to the distribution found in many other eucaryotic cells. As the cell population increases, the membranes condense around the nucleus. In completely confluent cultures when the cells cease to proliferate, the antigen is no longer detectable by immunofluorescence; its absence is confirmed by Western blotting experiments. Double‐labeling with antitubulin or phalloidin shows that the distribution of microtubules is not related to the distribution of the Ca2+‐regulating membranes whereas the actin fibers are superimposable onto the linearly oriented punctate vesicle‐like structures. If proliferating cells are treated with the volatile anesthetic isoflurane, the Ca2+‐regulating membranes can no longer be detected with the antibody; however, in Western blots the antigen is still present. Staining is restored after the removal of isoflurane. Such a temporary disappearance of the immunocytochemical staining might be explained by a transient oxidation and subsequent configuration change of the antigen, rendering the epitope inaccessible to the antibody, since a treatment with low concentrations of NaBH4 of cells exposed to isoflurane restores the access of the antigen to the antibody.
Risperidone in the treatment of psychoses in the elderly: a case report series
Authors: Bullock R. , Libretto S.
Published: July 2002

Risperidone is one of the newer atypical antipsychotic agents, which combines potent serotonin and dopamine receptor antagonism. It shows efficacy against the positive and negative symptoms of schizophrenic psychoses and other psychotic conditions, and has a low propensity to cause extrapyramidal side effects. The aim of these case reports in elderly patients is to provide the benefit of personal experience with risperidone to the body of published literature and to demonstrate the types of patients that may benefit from treatment. These cases were compiled retrospectively from data collected on referral and during routine hospital appointments. This series covers four main areas of concern when treating the elderly: low-maintenance dosing minimising the likelihood of adverse events; successful treatment of patients previously uncontrolled and experiencing side effects with other antipsychotics; the possibility of intermittent rather than continuous treatment; and the benefits to patients, carers and the health services. At low doses, risperidone is an effective and well-tolerated treatment for psychoses in elderly patients that improves the quality of life for both patients and their caregivers.
Dean Vortex Membrane Microfiltration and Diafiltration of rBDNF E.coliInclusion Bodies
Authors: Schutyser Maarten , Rupp Randall , Wideman Janusz , Belfort Georges
Published: July 2002

Cross‐flow microfiltration (CMF) and diafiltration were used to concentrate and purify recombinant Brain‐Derived Neutrophic Factor (rBDNF) inclusion bodies from an E. coli cell suspension and a homogenized E. coli cell suspension (homogenate/lysate). Although these processes have been tested industrially in pilot scale with conventional linear membrane microfiltration modules, their performances were severely limited due to membrane fouling. The purpose of this work was to determine whether Dean vortex microfiltration with controlled centrifugal instabilities (Dean vortices produced in helical flow) could be used to improve filtration performance over that observed with conventional linear cross‐flow microfiltration (CMF). For the microfiltration experiments with the feeds containing cell and homogenate suspensions, improvements in flux of about 50 and 70%, respectively, were obtained with the helical module as compared with that obtained with the linear module. For diafiltration with the homogenate suspension as feed, solute transport (as measured by mass) was from 100 to 40% higher after 40 and 100 min, respectively, with the helical module as compared with that obtained with the linear module. In the presence of the neutral surfactant, Tween 20, solute transport for diafiltration was at least 25 times higher during the first 10 min of operation and 100% higher after 300 min with the helical module as compared with that obtained with the linear module. Clearly, improved filtration performance, a purer and more concentrated product, and substantial savings can be expected with the new Dean vortex filters.
Purification and Identification of an Escherichiacoli β‐Keto Ester Reductase as 2,5‐Diketo‐d‐gluconate Reductase YqhE
Authors: Habrych Malgorzata , Rodriguez Sonia , Stewart Jon D.
Published: July 2002

An NADPH‐dependent enzyme that reduces ethyl 2‐methylacetoacetate stereoselectively to ethyl (2 R)‐methyl‐(3 S)‐hydroxybutanoate was purified 730‐fold from Escherichia coli. The N‐terminal amino acid sequence data obtained from the purified reductase were used to search the E. coli genome, and a single match was found at the start of the yqhE open reading frame. The YqhE protein had been identified previously by Yum et al. as a 2,5‐diketo‐d‐gluconate reductase on the basis of sequence similarity to other bacterial homologues [Yum, D.‐Y.; Lee, B.‐Y.; Pan, J.‐G. Appl. Environ. Microbiol. 1999, 65, 3341–3346]; however, it had not been examined for β‐keto ester reductions. Our results thus link a key enzyme in the microbial production of ascorbate with stereoselective β‐keto ester reductions, two important fields in biocatalysis. The purified YqhE reductase accepts ethyl acetoacetate and a variety of 2‐substituted derivatives, and its sequence is similar to other aldose reductase superfamily members that also reduce α‐substituted β‐keto esters to syn‐(2 R,3 S) alcohols.
Bioreactor Production of Human α1‐Antitrypsin Using Metabolically Regulated Plant Cell Cultures
Authors: Trexler Melody M. , McDonald Karen A. , Jackman Alan P.
Published: July 2002

Transgenic rice cell cultures, capable of producing recombinant human α1‐antitrypsin (rAAT), were scaled up from shake flasks to a 5‐L bioreactor. The maximum specific growth rates (μmax) observed from two bioreactor runs were 0.40 day−1(doubling time of 1.7 days) and 0.47 day−1(doubling time of 1.5 days), and the maximum specific oxygen uptake rates were 0.78 and 0.84 mmol O2/(g dw h). Using a metabolically regulated rice α‐amylase (RAmy3D) promoter, signal peptide, and terminator, sugar deprivation turned on rAAT expression, and rAAT was secreted into the culture medium. After 1 day of culture in sugar‐free medium, there was still continued biomass growth, oxygen consumption, and viability. Extracellular concentrations of 51 and 40 mg active rAAT/L were reached 1.7 and 2.5 days, respectively, after induction in a sugar‐free medium. Volumetric productivities for two batch cultures were 7.3 and 4.6 mg rAAT/(L day), and specific productivities were 3.2 and 1.6 mg rAAT/(g dw day). Several different molecular weight bands of immunoreactive rAAT were observed on immunoblots.
Chromatography for Rapid Buffer Exchange and Refolding of Secretory Leukocyte Protease Inhibitor
Authors: Hamaker Kent H. , Liu Jiyin , Seely Robert J. , Ladisch Christine M. , Ladisch Michael R.
Published: July 2002

A DEAE‐cellulose stationary phase in a rolled configuration was used to separate recombinant secretory leukocyte protease inhibitor (rSLPI) from denaturants and reducing agents (3 M guanidine‐HCl and 5 mM DTT) in less than 5 min to promote refolding of the protein to an active form. The mobile phase consisted of buffer and 500 mM NaCl, where NaCl suppressed binding of protein to this stationary phase. Separation of an initial concentration of 2 mg/mL protein from the other constituents resulted in 96% recovery of the rSLPI at an average concentration of 1.28 mg/mL. When incubated for 4 h at 20 °C, the fractionated rSLPI gave a 46% yield of properly refolded protein. The protein concentration was 6.4 times higher than that reported in a previously published method, where refolding was carried out by diluting the mixture of protein, denaturants, and reducing agents by a factor of 10. The results show that a combination of rapid chromatographic separation over a cellulosic stationary phase followed by protein refolding will significantly enhance process throughput by minimizing tankage, water requirements, and process time.
Novel, potent calmodulin antagonists derived from an all‐d hexapeptide combinatorial library that inhibit in vivo cell proliferation: activity and structural characterization
Authors: Blondelle S.E. , Crooks E. , Aligué R. , Agell N. , Bachs O. , Esteve V. , Tejero R. , Celda B. , Pastor M.T. , Pérez‐payá E.
Published: July 2002

Abstract: Calmodulin is known to bind to various amphipathic helical peptide sequences, and the calmodulin–peptide binding surface has been shown to be remarkably tolerant sterically. d‐Amino acid peptides, therefore, represent potential non‐hydrolysable intracellular antagonists of calmodulin. In the present study, synthetic combinatorial libraries have been used to develop novel d‐amino acid hexapeptide antagonists to calmodulin‐regulated phosphodiesterase activity. Five hexapeptides were identified from a library containing over 52 million sequences. These peptides inhibited cell proliferation both in cell culture using normal rat kidney cells and by injection via the femoral vein following partial hepatectomy of rat liver cells. These hexapeptides showed no toxic effect on the cells. Despite their short length, the identified hexapeptides appear to adopt a partial helical conformation similar to other known calmodulin‐binding peptides, as shown by CD spectroscopy in the presence of calmodulin and NMR spectroscopy in DMSO. The present peptides are the shortest peptide calmodulin antagonists reported to date showing potential in vivo activity.
Structure, biological activity and membrane partitioning of analogs of the isoprenylated a‐factor mating peptide of Saccharomyces cerevisiae
Authors: Xie H. , Becker J.M. , Gibbs R.A. , Naider F.
Published: July 2002

Abstract: Previous biochemical investigations on the Saccharomyces cerevisiaea‐factor indicated that this lipopeptide pheromone [YIIKGVFWDPAC(farnesyl)OMe] might adopt a type II β‐turn at positions 4 and 5 of the peptide sequence. To test this hypothesis, we synthesized five analogs of a‐factor, in which residues at positions 4 and 5 were replaced with: l‐Pro4(I); d‐Pro4(II); l‐Pro4‐d‐Ala5(III); d‐Pro4‐l‐Ala5(IV); or Nle4(V). Analogs were purified to > 99% homogeneity as evidenced by HPLC and TLC and were characterized by mass spectrometry and amino acid analysis. Using a growth arrest assay the conformationally restricted a‐factor analogs I and III were found to be almost 50‐fold more active than the diastereometric homologs II and IV and were equally active to wild‐type a‐factor. Replacement of Lys4 with the isosteric Nle4 almost abolished the activity of the pheromone. Thus, the incorporation of residues that promote a type II β‐turn compensated for the loss of the favorable contribution of the Lys4 side chain to pheromone activity. CD spectra on these peptides suggested that they were essentially disordered in both TFE/H2O and in the presence of DMPC vesicles. There was no correlation between CD peak shape and biological activity. Using fluorescence spectroscopy we measured the interaction of lipid vesicles with these position 4 and 5 analogs as well as with three a‐factor analogs with a modified farnesyl group. The results indicated that modifications of both the peptide sequence and the lipid moiety affect partitioning into lipid, and that no correlation existed between the propensity of a pheromone to partition into the lipid and its biological activity.
Entrapping unusual folding characteristics of the β‐Ala residues in a model peptide: Boc‐β‐Ala‐Aib‐β‐Ala‐NHCH3
Authors: Thakur A.K. , Kishore R. , Venugopalan P.
Published: July 2002

Abstract: Crystal structure analysis of a model peptide: Boc‐β‐Ala‐Aib‐β‐Ala‐NHCH3 (β‐Ala: 3‐amino propionic acid; Aib: α‐aminoisobutyric acid) revealed distinct conformational preferences for folded [φ≈136°, µ ≈ −62°, ψ ≈100°] and semifolded [φ ≈ 83°, µ ≈ −177°, ψ ≈ −117°] structures of the N‐ and C‐terminus β‐Ala residues, respectively. The overall folded conformation is stabilized by unusual Ni···H‐Ni+1 and nonconventional C–H···O intramolecular hydrogen bonding interactions.
Influence of the hydrophilic face on the folding ability and stability of α‐helix bundles: relevance to the peptide catalytic activity
Authors: Blondelle S.E. , Esteve V. , Celda B. , Pastor M.T. , Pérez‐Payá E.
Published: July 2002

Although not the sole feature responsible, the packing of amino acid side chains in the interior of proteins is known to contribute to protein conformational specificity. While a number of amphipathic peptide sequences with optimized hydrophobic domains has been designed to fold into a desired aggregation state, the contribution of the amino acids located on the hydrophilic side of such peptides to the final packing has not been investigated thoroughly. A set of self‐aggregating 18‐mer peptides designed previously to adopt a high level of α‐helical conformation in benign buffer is used here to evaluate the effect of the nature of the amino acids located on the hydrophilic face on the packing of a four α‐helical bundle. These peptides differ from one another by only one to four amino acid mutations on the hydrophilic face of the helix and share the same hydrophobic core. The secondary and tertiary structures in the presence or absence of denaturants were determined by circular dichroism in the far‐ and near‐UV regions, fluorescence and nuclear magnetic resonance spectroscopy. Significant differences in folding ability, as well as chemical and thermal stabilities, were found between the peptides studied. In particular, surface salt bridges may form which would increase both the stability and extent of the tertiary structure of the peptides. The structural behavior of the peptides may be related to their ability to catalyze the decarboxylation of oxaloacetate, with peptides that have a well‐defined tertiary structure acting as true catalysts.
Chaperone‐like activity of a synthetic peptide toward oxidized γ‐crystallin
Authors: Kumar R.S. , Sharma K.K.
Published: July 2002

αA‐Crystallin can function like a molecular chaperone. We recently reported that the αA‐crystallin sequence, KFVIFLDVKHFSPEDLTVK (peptide‐1, residues 70–88) by itself possesses chaperone‐like (anti‐aggregating) activity during a thermal denaturation assay. Based on the above data we proposed that the peptide‐1 sequence was the functional site in αA‐crystallin. In this study we investigated the specificity of peptide‐1 against γ‐crystallin aggregation in the presence of H2O2 and CuSO4. Peptide‐1 was able to completely protect against the oxidation‐induced aggregation of γ‐crystallin. Removal of N‐terminal Lys or the replacement of Lys with Asp (DFVIFLDVKHFSPEDLTVK, peptide‐2) did not alter the anti‐aggregation property of peptide‐1. However, deletion of KF residues from the N‐terminus of peptide‐1 resulted in a significant loss of its anti‐aggregation property. Bio‐gel P‐30 size‐exclusion chromatography of γ‐crystallin incubated with peptide‐2 under oxidative conditions revealed that a major portion of the peptide elutes in the void volume region along with γ‐crystallin, suggesting the binding of the peptide to the protein. Peptide‐1 and ‐2 were also able to prevent the UV‐induced aggregation of γ‐crystallin. These data indicate that the same amino acid sequence in αA‐crystallin is likely to be responsible for suppressing the heat‐denatured, oxidatively modified and UV‐induced aggregation of proteins.
Study of the conformational profile of the cyclohexane analogs of l‐phenylalanine
Authors: Gomez‐Catalan J. , Jimenez A.I. , Cativiela C. , Perez J.J.
Published: July 2002

Abstract: The conformational profile of the conformationally constrained cyclohexane analogs of phenylalanine (1‐amino‐2‐phenylcyclohexanecarboxylic acids, c6Phe) was assessed using computational methods. For this purpose, the conformational space of the N‐acetyl methylamide derivatives of the stereoisomers (2S,3R)c6Phe and (2S,3S)c6Phe was explored by computing their respective Ramachandran maps, and low‐energy minima were characterized at molecular mechanics level by means of the amber program, using the parm94 force field set of parameters. In order to assess the performance of the molecular mechanics calculations, each of the low‐energy conformations was also investigated further at the ab initio level. Accordingly, the molecular mechanics geometries were used as starting conformations to perform full geometry optimizations at the Hartree‐Fock level, using a 6‐31G(d) basis set. Analysis of the results revealed that the cyclohexane structure directly induces some restrictions on the backbone, and constrains the orientation of the aromatic side‐chain to two narrow regions for each stereoisomer. The conformational profile of these amino acids is then explained on the grounds of the interaction between the rigidly held phenyl ring and the main chain NH and CO groups. The results obtained are in good accordance with the experimental observations.
Childhood asthma admissions: Determinants of short stay
Authors: Dell Sharon D. M. , Parkin Patricia C. , Macarthur Colin
Published: July 2002

The objective of this study was to identify the determinants of short hospital stay (< 24 h) among children admitted because of an acute asthma exacerbation. Computerized health records were used to identify children with a discharge diagnosis of asthma (ICD code 493.0) at the Hospital for Sick Children, Toronto, during the period October 1994 to October 1995. Cases were children with a length of hospital stay of < 24 h (short‐stay group) and controls were children with a length of stay of > 24 h (long‐stay group). Clinical and demographic data were extracted from the medical record. Over the 12‐month period, 485 children were hospitalized because of asthma. Of these, 121 (25%) had short‐stay admissions (< 24 h), whereas 364 (75%) had long‐stay admissions (> 24 h). Simple random sampling was used to select 85 children from each of the two groups. There were no differences between the two groups regarding language, primary care physician, asthma history, management prior to emergency department (ED) presentation, respiratory rate on presentation, use of the observation unit, and time in the ED. Logistic regression analyses identified three variables associated with short hospital stay: milder asthma (adjusted odds ratio [OR] 4.9), male gender (adjusted OR 2.4), and availability of a delivery device at home (adjusted OR 2.0). In conclusion, many children admitted to hospital because of an asthma exacerbation have short, yet expensive, hospital stays. The results of this study highlight the importance of developing alternative models of health care delivery for asthmatic children requiring short hospital contact.
A computer simulation of aggregated phytochrome photoconversion
Authors: Ninković V. , Obrenović S.
Published: July 2002

In order to check the relevance of possible phytochrome aggregation forms for the diversity of action spectra and dose‐response curves for light sensing by plants, a model for phytochrome photoconversion was produced for different aggregates. Under saturating light treatments, a computer simulation of dimer and aggregated dimer (tetramers and hexamers) photoconversion provided similar compositions of various aggregates in red and green light, which differed from blue and far‐red light. These aggregates could account for the variable action spectra only if the nature of the primary transducing components is taken into account. The initial kinetics of aggregated phytochrome appear to be slower in comparison to the monomeric form, and there were transient peaks of certain aggregates in red and green light. A single peak occurred under blue light, but not in far‐red, only if dimers are aggregated into tetramers and hexamers. This finding suggests that the initial kinetics of aggregated phytochrome are not sufficient to account for the variable dose‐response curves in light‐mediated responses by plants, so again the feature of signal transduction components may play a decisive role.
Purification of the Escherichia coli ammonium transporter AmtB reveals a trimeric stoichiometry
Authors: BLAKEY Dan , LEECH Andrew , THOMAS Gavin H. , COUTTS Graham , FINDLAY Kim , MERRICK Mike
Published: July 2002

The Amt family of high-affinity ammonium transporters is a family of integral membrane proteins that are found in archaea, bacteria, fungi, plants and animals. Furthermore, the family has recently been extended to humans with the recognition that both the erythroid and non-erythroid Rhesus proteins are also ammonium transporters. The Escherichia coli AmtB protein offers a good model system for the Amt family and in order to address questions relating to both its structure and function we have overproduced a histidine-tagged form of the protein (AmtB6H) and purified it to homogeneity. We examined the quaternary structure of AmtB6H (which is active in vivo) by SDS/PAGE, gel-filtration chromatography, dynamic light scattering and sedimentation ultracentrifugation. The protein was resistant to dissociation by SDS and behaved as a stable oligomer on SDS/PAGE. By equilibrium desorption chromatography we determined the mass ratio of dodecyl β-d-maltoside to AmtB in the detergent-solubilized complex to be 1.03±0.03, and this allowed us to calculate, from analytical-ultracentrifugation data, that AmtB purifies as a trimer.
Role of ATP-binding motifs on DNA-binding activity and biological function of Rhp51, a Rad51 homologue in fission yeast
Authors: KIM Woo J. , LEE Hyojin , PARK Eon J. , HONG Seung H. , PARK Sang D.
Published: July 2002

Rhp51, a RecA and Rad51 homologue of Schizosaccharomyces pombe, plays a pivotal role in homologous recombination and recombinational repair. It has a set of the well-conserved type A and type B ATP-binding motifs, which are highly conserved in all RecA homologues. In a previous study [Kim, Lee, Park, Park and Park (2001) Nucleic Acids Res. 29, 1724–1732], we reported that a single mutation of the conserved lysine in A motif [Lys155→Ala (K155A)] destroyed the DNA repair ability of Rhp51 and that overexpression of this mutant protein conferred dominant negativity. In the present paper, we investigated DNA-binding properties of recombinant Rhp51 and its mutant proteins. Purified Rhp51 protein showed ATP-dependent double- and single-strand DNA-binding activities. To characterize the role of ATP-binding motifs, we generated Rhp51 K155A and Rhp51 Asp244→Gln (D244Q), which have a single amino acid substitution in A and B motifs respectively. Interestingly, K155A and D244Q mutations impaired ATP-dependent DNA binding in a different manner. K155A lost the DNA binding itself, whereas D244Q maintained the binding ability but lost the ATP dependency. However, despite the difference in DNA-binding ability, both mutations failed to rescue the methylmethane sulphonate and UV sensitivity of the rhp51Δ mutant. Together, these results suggested that not only the DNA binding but also the ATP dependence in DNA binding is required for proper in vivo functioning of Rhp51.
Formation of non‐resorbing osteoclasts from peripheral blood mononuclear cells of patients with malignant juvenile osteopetrosis
Authors: Helfrich M. H. , Gerritsen E. J. A.
Published: July 2002

The genetic defects that cause human infantile malignant osteopetrosis, a disease with recessive inheritance characterized by lack of bone resorption and the presence of large numbers of inactive osteoclasts, are only partially known. Studies of osteoclasts in vitro may help to identify or exclude candidate genes in this disorder. Here, we established co‐cultures of peripheral blood mononuclear cells with mouse fetal bone rudiments to generate osteoclasts from three infants with malignant osteopetrosis. Osteoclasts generated in vitro displayed the same inability to form ruffled borders and resorb bone as seen in bone biopsies. This culture model may contribute to understanding the pathogenesis of this disease.
A Hamiltonian approach to asymptotic seismic reflection and diffraction modelling
Authors: Hanyga A. , Druzhinin A.B. , Dzhafarov A.D. , Frøyland L.
Published: July 2002

A model‐independent Hamiltonian formulation of paraxial and diffracted ray‐tracing equations is presented. It is applied to asymptotic Green's function computations. The medium can have an arbitrary number of interfaces, possibly intersecting at diffracting edges and vertices. Continuously varying model parameters and anisotropy are allowed. The algorithm for elastic waves, involving accuracy control and amplitude computation, is implemented in a platform‐independent object‐orientated C++ package. Numerical tests and modelling examples are presented.
Stereological estimates of nuclear star volume and vessels as predictors of chemotherapy response in small cell carcinoma of the lung: a preliminary report
Authors: Caporrino C , Saldiva P H N , Farhat C A V , Takagaki T Y , Younes R N , Capelozzi V L
Published: July 2002

Aims

This study was designed to evaluate the role of morphometric and clinical parameters in predicting chemotherapy responder patients with small cell carcinoma of the lung.

Methods and results

Morphometric studies were performed by means of point counting techniques. Forty‐six patients were included in this study. Group 1 patients (n = 19) were those without response to chemotherapy; Group 2 (n = 27) was composed by patients with partial or complete response to chemotherapy. Logistic regression analysis was used to attain the best separation of non‐responder from responder patients. Star volume of the nuclei and vessel were selected during the backward procedure as relevant variables to characterize the two groups of patients. The overall sensitivity of the model was 80.4 3%.

Conclusions

Our results indicate that histopathological data may help to predict the chemotherapy response in patients with small cell lung carcinoma, and encourage the use of morphometric procedures in histopathological analysis of this type of lung tumours.
Placenta praevia and male sex at birth: results from a population‐based study
Authors: Wu Wen S. , Demissie K. , Liu S. , Marcoux S. , Kramer M.S.
Published: July 2002

This study examined the relationship between male sex at birth and placenta praevia in 433 031 mother/infant dyads (linked by a common institutional code and hospital admission number) in the Canadian province of Quebec, during the fiscal years of 1991/92–1995/96. The male‐to‐female ratio among pregnancies with and without placenta praevia was calculated and compared. The male‐to‐female ratio at birth was higher in pregnancies complicated by a placenta praevia (1.19) than in those without it (1.04; P < 0.02). This increased ratio persisted after accounting separately for the potential confounding and/or modifying effects of maternal age, infant birthweight and gestational age by stratified and multiple logistic regression analyses. We conclude that pregnant women with male babies carry a higher risk of placenta praevia.
Carrots, carotene and seeing in the dark
Authors: Smith Wayne , Mitchell Paul , Lazarus Ross
Published: July 2002

Should older people eat more carrots, or at least increase their carotene intake to prevent loss of night vision? Participants in the Blue Mountains Eye Study were asked about their ability to see in the dark. Nutrient and food intake were estimated from a food frequency questionnaire. Associations between self‐reported poor night vision and estimated nutrient intake were investigated using logistic regression. Poor night vision among women was associated with higher beta‐carotene (P for trend = 0.03) and total vitamin A intake (P for trend = 0.048). Increased consumption of carrots, but no other food high in beta‐carotene, was associated with significant increased reporting of poor night vision among women (P for trend = 0.04). While carrot intake may protect against difficulty in seeing at night, it is probable that people attributing poor driving ability to their vision may be eating more carrots in the hope of reversing this decline.
Managing many patients with a urethral stricture:
Authors: Ogbonna
Published: July 2002

Objectives

 To report a management method in a community where there are many patients with urethral stricture and where the short‐term goal of providing some treatment to most may override the sometimes conflicting long‐term aim of minimizing recurrence rates.

Patients and methods

 Over a 3‐year period, using optical urethrotomy in 76 patients followed by intermittent self‐dilatation (ISD) in 29, urethroplasty in 28 and dilatation in three, 92 of 134 patients with a urethral stricture were treated and the outcome compared.

Results

 The overall recurrence rate was 22%; a combination of urethrotomy plus ISD had a recurrence rate of 17% and gave a mean duration of follow‐up without recurrence similar to that after urethroplasty. ISD significantly increased both the time before recurrence and the duration of follow‐up without recurrence after urethrotomy. In addition to providing lasting treatment to many patients, urethrotomy was also 10 times cheaper, 10 times faster to perform and offered the surgeon better protection from infection with human immunodeficiency virus than did urethroplasty.

Conclusion

 Because wrongly selecting urethrotomy (resulting in a failed procedure) wastes valuable operating time and resources, the pre‐operative recognition of strictures unsuitable for urethrotomy and their treatment by urethroplasty is important for overall efficiency.
Impact of cigarette smoking on the incidence of Type 2 diabetes mellitus in middle‐aged Japanese men: the Osaka Health Survey
Authors: Uchimoto S. , Tsumura K. , Hayashi T. , Suematsu C. , Endo G. , Fujii S. , Okada K.
Published: July 2002

Aims To assess the impact of cigarette smoking on the incidence of Type 2 diabetes mellitus (DM) in middle‐aged Japanese men.

Methods The study enrolled 6250 men aged 35–60 years and free of diabetes, impaired fasting glucose and hypertension at entry. Type 2 DM was defined by a fasting plasma glucose level ≥ 7.0 mmol/l or physician‐diagnosed Type 2 DM.

Results Four hundred and fifty cases of Type 2 DM were confirmed during the 60 904 person‐years follow‐up. After adjustment for multiple covariates, including age, body mass index, alcohol consumption, physical activity, parental history of diabetes and the level of fasting plasma glucose, total cholesterol, triglycerides, high‐density lipoprotein cholesterol and haematocrit, the relative risk of Type 2 DM among current smokers compared with non‐smokers was 1.47 (95% confidence interval (CI) 1.14–1.92). Men who smoked > 30 cigarettes/day had a multivariate‐relative risk of 1.73 (95% CI 1.20–2.48) compared with non‐smokers. The number of cigarettes smoked daily and the pack‐year values were positively related to the development of Type 2 DM in a dose‐dependent manner (P for trends = 0.0026 and 0.001, respectively).

Conclusions A cigarette smoking habit is an independent risk factor for Type 2 DM.
Application of the new ADA criteria for the diagnosis of diabetes to population studies in sub‐Saharan Africa
Authors: Levitt N. S. , Unwin N. C. , Bradshaw D. , Kitange H. M. , Mbanya J. ‐C. N. , Mollentze W. F. , Omar M. A. K. , Motala A. A. , Joubert G. , Masuki G. , Machibya H.
Published: July 2002

Aims To examine the implications for epidemiological studies of the American Diabetes Association (ADA) recommendation that the fasting blood glucose at a lowered level becomes the main diagnostic test for diabetes on cross‐sectional‐based data from sub‐Saharan Africa.

Methods Data from 11 surveys conducted in rural, peri‐urban and urban Cameroon (n = 1804), South Africa (n = 3799) and Tanzania (n = 10013) which measured fasting (ADA criteria) and 2‐h blood glucose concentrations during a standard 75 g OGTT (old WHO criteria) were analysed.

Results The prevalence of diabetes was higher in eight of the 11 surveys when applying the new ADA compared to the old WHO criteria. With the exception of one population (Mara, Tanzania) the absolute difference in prevalence between the two classifications tended to be small (< 2%). There was considerable variation in the categorization of individuals using the ADA and old WHO criteria. The level of agreement between the two ranged from fair to good (Kappa statistic 0.17–0.86). The prevalence of impaired fasting glycaemia (IFG) was lower than that of impaired glucose tolerance (IGT) in 10 of the surveys and the agreement between the two was fair,  0.26 in all the surveys.

Conclusions Although the use of the new ADA fasting criteria for prevalence surveys is an attractive and practical option, particularly in Africa, further information is required on the characteristics and prognosis of individuals classified as IFG or diabetic by the fasting criteria, prior to wide adoption of the ADA criteria. Ideally measurement of both fasting and two low glucose concentrations should remain the standard for epidemiological studies.