bluuebunny/crossref_metadata_2025 huggingface dataset:
Inositol(1,3,4,5) tetrakisphosphate plays an important role in calcium mobilization from Entamoeba histolytica
Authors: Raha Sanghamitra , Giri Banabihari , Bhattacharyya Bhudeb , Biswas Birendra B
Published: July 2002

Calcium release from internal stores of Entamoeba histolytica, a parasitic protozoan, was observed by measuring fluorescence of Fura‐2. Emptying of inositol(1,4,5)trisphosphate (Ins(1,4,5)P3)‐sensitive calcium pools in permeabilized E. histolytica did not significantly affect subsequent calcium release by inositol(1,3,4,5)tetrakis‐phosphate (Ins(1,3,4,5)P4). Similarly, prior depletion of Ins(1,3,4,5)P4‐sensitive stores did not have any influence on subsequent calcium release by Ins(1,4,5)P3. The EC50 for calcium release was 0.15 μM with Ins(1,4,5)P3 and 0.68 μM with Ins(1,3,4,5)P4. In conclusion, the Ins(1,3,4,5)P4‐sensitive calcium store in E. histolytica is separate and independent from the Ins(1,4,5)P3‐sensitive pool.
The solution structure of the active domain of CAP18 — a lipopolysaccharide binding protein from rabbit leukocytes
Authors: Chen Chinpan , Brock Roland , Luh Frederick , Chou Ping-Jung , Larrick James W. , Huang Rong-Fong , Huang Tai-huang
Published: July 2002

We have employed the circular dichroism (CD) technique to characterize the solution structure of CAP18106–137, a lipopolysaccharide (LPS) binding, antimicrobial protein, and its interaction with lipid A. Our results revealed that CAP18106–137 may exist in at least three lipid A concentration‐dependent, primarily helix conformations. The ‘model’ structure of CAP18106–137 in 30% (v/v) TFE, determined by nuclear magnetic resonance (NMR) technique, was found to be a complete and very rigid helix. In this conformation, the cationic and hydrophobic groups of CAP18106–137 are separated into patches and stripes in such a way that it can favorably interact with lipid A through either coulombic interaction with the diphosphoryl groups or hydrophobic interaction with the fatty acyl chains.
The Drosophila learning and memory gene linotte encodes a putative receptor tyrosine kinase homologous to the human RYK gene product
Authors: Dura Jean-Maurice , Taillebourg Emmanuel , Préat Thomas
Published: July 2002

The linotte mutant was isolated on the basis of its learning and memory deficit. Interestingly, linotte individuals carrying a null mutation are viable, indicating that the linotte gene is not required for vital functions. We show here that the linotte gene encodes a putative receptor tyrosine kinase, homologous to the human protein RYK. These products are unique among receptor tyrosine kinases, since they possess a short extra cellular domain, and a modified intracellular catalytic domain. In particular, the subdomains directly involved in ATP binding and phosphotransfer reaction display remarkable variations. These results suggest that linotte is part of a novel signal transduction cascade involved in learning and memory.
RK‐682, a potent inhibitor of tyrosine phosphatase, arrested the mammalian cell cycle progression at G1phase
Authors: Hamaguchi Takuya , Sudo Tatsuhiko , Osada Hiroyuki
Published: July 2002

A specific inhibitor of protein tyrosine phosphatase (PTPase), RK‐682 (3‐hexadecanoyl‐5‐hydroxymethyl‐tetronic acid) was isolated from microbial metabolites. In vitro, RK‐682 inhibited dephosphorylation activity of CD45 and VHR with IC50 54 and 2.0 μM, respectively. In situ, sodium orthovanadate and RK‐682 enhanced the phosphotyrosine level of Ball‐1 cells, a human B cell leukemia, but not the phosphoserine/threonine level. The PTPase inhibitors, however, had the different arrest point on the cell cycle progression. Sodium orthovanadate inhibited the cell cycle progression at G2/M boundary phase, on the other hand, RK‐682 inhibited the G1/S transition.
Cloning and sequencing of a human thioredoxin reductase
Authors: Gasdaska Pamela Y. , Gasdaska John R. , Cochran Shawn , Powis Garth
Published: July 2002

The DNA sequence encoding human placental thioredoxin reductase has been determined. Of the 3826 base pairs sequenced, 1650 base pairs were in an open reading frame encoding a mature protein with 495 amino acids and a calculated molecular mass of 54,171. Sequence analysis showed strong similarity to glutathione reductases and other NADPH‐dependent reductases. Human thioredoxin reductase contains the redoxactive cysteines in the putative FAD binding domain and has a dimer interface domain not previously seen with prokaryote and lower eukaryote thioredoxin reductases.
Fibromodulin and lumican bind to the same region on collagen type I fibrils
Authors: Svensson Liz , Närlid Ingmar , Oldberg Åke
Published: July 2002

Fibromodulin and lumican are closely related members of the extracellular matrix leucine‐rich repeat glycoprotein/proteoglycan family. Similar to decorin, another member of this protein family, they bind to fibrillar collagens and function in the assembly of the collagen network in connective tissues. We have studied the binding of recombinant fibromodulin, lumican and decorin, expressed in mammalian cells, to collagen type I. Using a collagen fibril formation/sedimentation assay we show that fibromodulin inhibits the binding of lumican, and vice versa. Fibromodulin and lumican do not affect the binding of decorin to collagen, nor does decorin inhibit the binding of fibromodulin or lumican. Binding competition experiments and Scatchard plot analysis indicate that fibromodulin binds to collagen type I with higher affinity than lumican.
Mutagenic analysis of Thr‐232 in rhodanese from Azotobacter vinelandii highlighted the differences of this prokaryotic enzyme from the known sulfurtransferases
Authors: Pagani Silvia , Forlani Fabio , Carpen Aristodemo , Bordo Domenico , Colnaghi Rita
Published: July 2002

Azotobacter vinelandii RhdA uses thiosulfate as the only sulfur donor in vitro, and this apparent selectivity seems to be a unique property among the characterized sulfurtransferases. To investigate the basis of substrate recognition in RhdA, we replaced Thr‐232 with either Ala or Lys. Thr‐232 was the target of this study since the corresponding Lys‐249 in bovine rhodanese has been identified as necessary for catalytic sulfur transfer, and replacement of Lys‐249 with Ala fully inactivates bovine rhodanese. Both T232K and T232A mutants of RhdA showed significant increase in thiosulfate‐cyanide sulfurtransferase activity, and no detectable activity in the presence of 3‐mercaptopyruvate as the sulfur donor substrate. Fluorescence measurements showed that wild‐type and mutant RhdAs were overexpressed in the persulfurated form, thus conferring to this enzyme the potential of a persulfide sulfur donor compound. RhdA contains a unique sequence stretch around the catalytic cysteine, and the data here presented suggest a possible divergent physiological function of A. vinelandii sulfurtransferase.
A novel fluorescent probe diphenyl‐1‐pyrenylphosphine to follow lipid peroxidation in cell membranes
Authors: Okimoto Yuko , Watanabe Akira , Niki Etsuo , Yamashita Takashi , Noguchi Noriko
Published: July 2002

Diphenyl‐1‐pyrenylphosphine (DPPP) was tested whether it could be used as a fluorescent probe to monitor lipid peroxidation in cell membranes. DPPP reacted with organic hydroperoxides and hydrogen peroxide stoichiometrically to give DPPP oxide (DPPP=O). DPPP incorporated into phosphatidylcholine liposomal membranes and polymorphonuclear leukocytes (PMNs) reacted with methyl linoleate hydroperoxide rapidly but not with hydrogen peroxide nor with tert‐butyl hydroperoxide. This novel method revealed that lipid peroxidation proceeded within membranes of PMNs stimulated with phorbol 12‐myristate 13‐acetate, which is known to produce several kinds of free radicals. It was found that DPPP is a suitable fluorescent probe to monitor lipid peroxidation within cell membranes specifically.
An EVH1/WH1 domain as a key actor in TGFβ signalling
Authors: Callebaut Isabelle
Published: July 2002

EVH1 (enabled VASP (vasodilator‐stimulated protein) homology 1)/WH1 (WASP (Wiskott–Aldrich syndrome protein) homology 1) domains, present in Ena VASP and WASP, are protein interaction modules specialised in binding proline‐rich ligands. An EVH1/WH1 domain is here identified in the recently cloned SMIF protein, a key protein in transforming growth factor‐β (TGFβ) signalling which was not yet related to defined domains. The SMIF EVH1/WH1 domain interacts with the proline‐rich Smad4 activation domain, leading to translocation of so‐formed complex to the nucleus where SMIF possesses strong intrinsic TGFβ‐inducible transcriptional activity. This finding highlights the pivotal role that the EVH1/WH1 family of domains play in multiple eukaryotic signal transduction pathways.
Bacillusthuringiensis cry3Ca1 Protein Is Toxic to the Colorado Potato Beetle, Leptinotarsadecemlineata (Say)
Authors: Haffani Yosr Z. , Cloutier Conrad , Belzile François J.
Published: July 2002

We expressed the wild‐type cry3Aa3 and cry3Ca1 Bacillus thuringiensis genes, which code for insecticidal proteins, in an Escherichia coli expression system. Highly purified preparations of the soluble δ‐endotoxins were used to perform comparative bioassays with third‐instar larvae of the Colorado potato beetle (CPB). Acute mortality data showed that Cry3Ca1 (LD50 = 320.1 ng) was 2‐fold more toxic than Cry3Aa3 (LD50 = 672.9 ng). We also compared the chronic effects of sublethal doses of these toxins by measuring the consumption of untreated foliage and monitoring survival and development for 6 days after intoxication. No significant additional mortality was recorded, but we found that surviving larvae fed Cry3Ca1 consumed foliage at a slower rate than the larvae fed Cry3Aa3, suggesting more damage to their digestive epithelium. This study, the first assessment of the toxicity of cry3Ca1 in third‐instar CPB, suggests cry3Ca1 will prove useful for the control of this important insect pest.
Mechanical Stability of Immobilized Biocatalysts (CLECs) in Dilute Agitated Suspensions
Authors: Lee Timothy S. , Turner Michael K. , Lye Gary J.
Published: July 2002

Cross‐linked enzyme crystals (CLECs) are a novel form of immobilized biocatalyst designed for application in industrial biotransformation processes. In this work we have investigated the mechanical stability of agitated CLEC suspensions in relation to the design and scale‐up of bioconversions carried out in stirred‐tank reactors. By careful control of the crystallization conditions yeast alcohol dehydrogenase I (YADHI) microcrystals of different size were first prepared having either an hexagonal (∼12 μm) or rod‐shaped (∼4.6 μm) morphology. These were then cross‐linked with glutaraldehyde to form CLECs. The rate of breakage of the CLEC suspensions was subsequently measured in a rotating disk shear device (total volume, 11 mL) by monitoring the change in crystal size distribution with time. This device is designed to mimic the shear and energy dissipation rates found in a range of process scale equipment and may be used to study the mechanical stability of any immobilized biocatalyst preparation. Experiments were performed as a function of the speed and duration of disk rotation, CLEC concentration (0.26–2.5 mg·mL−1) and energy dissipation rate (2.2 × 103 to 6.8 × 105 W·kg−1). No breakage of the rod‐shaped CLECs was observed over the entire range of experimental conditions investigated. Breakage of the larger hexagonal‐shaped CLECs did occur, however, at energy dissipation rates, ϵmax, above 1.0 × 105 W·kg−1, where the calculated length scale of turbulence was around 2.0 μm. Based on visual observation of the sheared CLEC suspensions and models of crystal breakage, it was concluded that breakage of the hexagonal‐shaped CLECs occurred due to shear induced attrition. Measurement of the catalytic activity of both the hexagonal and rod‐shaped CLECs showed no significant change in activity before and after shearing.
Process and Economic Evaluation of the Extraction and Purification of Recombinant β‐Glucuronidase from Transgenic Corn
Authors: Evangelista Roque L. , Kusnadi Ann R. , Howard John A. , Nikolov Zivko L.
Published: July 2002

A process model for the recovery and purification of recombinant β‐glucuronidase (rGUS) from transgenic corn was developed, and the process economics were estimated. The base‐case bioprocessing plant operates 7500 h/year processing 1.74 million (MM) kg of transgenic corn containing 0.015% (db) rGUS. The process consists of milling the corn into flour, extraction of protein by using 50 mM sodium phosphate buffer, and rGUS purification by ion exchange and hydrophobic interaction chromatography. About 137 kg of rGUS of 83% (db) purity can be produced annually. The production cost amounted to $43 000/kg of rGUS. The cost of milling, protein extraction, and rGUS purification accounted for 6, 40, and 48% of annual operating cost, respectively. The cost of transgenic corn was 31% of the raw material costs or 6% of the annual operating cost. About 78% of the cost of buffer and water were incurred in the protein extraction section, while 88% of other consumables were from the purification section. The sensitivity analysis indicated that rGUS can be produced profitably from corn even at the 0.015% (db) expression level, assuming a selling price of $100 000/kg GUS. An increase in rGUS expression levels up to 0.08% significantly improves the process economics.
DNA‐based vaccination for the treatment of food allergy
Authors: Nguyen Minh‐Duc , Cinman Nadya , Yen Jack , Horner Anthony A.
Published: July 2002

At present, avoidance is the only therapeutic option available for individuals with food allergies. However, studies suggest that DNA‐based vaccination might be an effective therapeutic option for the reversal of allergic hypersensitivities, including allergies to foods. Because severe anaphylactic reactions represent a life‐threatening risk for individuals with food allergies, we and others have evaluated the effectiveness of DNA‐based vaccination for the prevention of anaphylactic hypersensitivity in murine models. Our investigations demonstrated that primary gene and protein/immunostimulatory sequence oligodeoxynucleotide (ISS‐ODN) vaccination of subsequently Th2‐sensitized mice reduced the risk of death after anaphylactic challenge, significantly. In addition, gene and protein/ISS‐ODN vaccination reduced post challenge plasma histamine levels. Analysis of the immune profiles of mice receiving DNA‐based vaccines showed that both gene and protein/ISS‐ODN vaccination effectively prevented the development of Th2‐biased immune profiles after sensitization. In contrast, vaccination with protein alone, the experimental equivalent of the traditional protein‐based immunotherapy (IT) reagents used in clinical practice provided no protection from anaphylaxis, nor did it prevent the development of a Th2‐biased immune profile after allergen sensitization. These studies justify continued optimism in the potential of DNA‐based vaccination for the desensitization of food allergic individuals.
Dipeptide derivative synthesis catalyzed by Pseudomonas aeruginosa elastase
Authors: Rival S. , Besson C. , Saulnier J. , Wallach J.
Published: July 2002

Pseudomonas aeruginosa elastase was used to synthesize various N‐protected dipeptide amides. The identity of the products was confirmed by FAB+‐MS. After recrystallization, the yield of their synthesis was calculated, their purity was checked by RP‐HPLC and their melting point was measured. With regard to the hydrolysis, it is well‐established that the enzyme prefers hydrophobic amino acids in P′1 position and it has a wide specificity for the P1 position. This specificity was demonstrated to be quite unchanged when comparing the initial rates of peptide bond formation between different carboxyl donors (Z‐aa) and nucleophiles (aa‐NH2). The elastase, but not the thermolysin, was notably able to incorporate tyrosine and tryptophan in P′1 position. Furthermore, synthesis initial rates were at least 100 times faster with the elastase. To overcome the problematic condensation of some amino acids during chemical peptide synthesis, it has been previously suggested that enzymatic steps can combine with a chemical strategy. We demonstrated that the elastase readily synthesizes dipeptide derivatives containing various usual N‐protecting groups. It was especially able to condense phenylalaninamide to Fmoc‐ and Boc‐alanine. Increasing interest in peptides containing unnatural amino acids led us to try the elastase‐catalyzed synthesis of Z‐dipeptide amides including those amino acids in the P1 position. A synthesis was demonstrated with αAbu, Nle, Nva and Phg.
A contiguous deletion syndrome of X‐linked agammaglobulinemia and sensorineural deafness
Authors: Richter Darko , Conley Mary Ellen , Rohrer Jurg , Myers Laurie A. , Zahradka Katarina , Keleč Ić Jadranka , Sertić Jadranka , Stavljenić ‐Rukavina Ana
Published: July 2002

Hearing loss in patients with X‐linked agammaglobulinemia is often attributed to recurrent infections. However, recent genetic studies suggest a different etiology in some patients. We present three unrelated patients, 6, 9, and 14 years of age, with large deletions of the terminal portion of the Bruton tyrosine kinase (Btk) gene extending 4.2–19 kb beyond the 3′ end of the gene. The DNA immediately downstream of the 3′ end of Btk contains the deafness‐dystonia protein gene (DDP). Mutations in this gene have recently been shown to underlie the Mohr–Tranebjaerg syndrome, which is characterized by sensorineural deafness, dystonia, and mental deficiency. Besides the immunodeficiency, our patients exhibited progressive sensorineural deafness. The clue to an associated hearing problem was delayed development of speech in one patient and post‐lingual deafness noticed between the age of 3–4 years in the other two. These patients have not yet exhibited significant associated neurologic deficits.
Association of α‐amylase and the R1 protein with starch granules precedes the initiation of net starch degradation in turions of Spirodela polyrhiza
Authors: Reimann Rezarta , Ritte Gerhard , Steup Martin , Appenroth Klaus‐J.
Published: July 2002

In turions of Spirodela polyrhiza (L.) Schleiden, net degradation of storage starch is controlled by a special low fluence response of phytochrome requiring illumination for several days. This light effect has been used to study protein–starch interactions that occur prior to and during net degradation of starch. Following various pretreatments on S. polyrhiza turions, native starch granules were isolated and two fractions of starch‐related proteins were distinguished: proteins enclosed within the starch particles (starch‐internalized proteins) and those attached to the surface (starch‐associated proteins). The pattern of starch‐associated proteins as resolved by SDS‐PAGE was more complex than that of starch‐internalized proteins and varied depending upon the pretreatment of the turions. Two starch associated proteins were identified immunochemically as α‐amylase (EC 3.2.1.1) and the R1 protein (Lorberth et al. (1998) Nature Biotechnology 16: 473–477). Dark‐pretreatment of non‐dormant turions does not induce starch net degradation. Under these conditions, α‐amylase and R1 were bound to the surface of the starch granules. Continuous illumination with red light induces a rapid degradation of starch. Within the first 24 h of illumination the level of starch‐associated α‐amylase transiently increased and subsequently decreased rapidly. Similarly, the amount of the starch‐associated R1 also decreased during illumination. The dissociation of both α‐amylase and R1 from the starch granules preceded the decrease in starch content. However, binding of the two proteins to starch granules remained unchanged when the turions did not perform net starch degradation (as observed during continuous darkness, orthophosphate deficiency, or dormancy of the turions). Thus, during net starch degradation, so far unidentified changes are postulated to occur at the surface of the starch particles that are relevant for protein binding. This conclusion was supported by in vitro studies in which the binding of purified β‐amylase (EC 3.2.1.2) to starch granules isolated from turions following various pretreatments was monitored. The enzyme did bind to starch granules prepared from dark‐stored turions (in which starch degradation had not been initiated), but not to those isolated from illuminated (starch degrading) turions.
Haemangiopericytoma: histological spectrum, immunohistochemical characterization and prognosis
Authors: Mazzei Maurizio , Millanta Francesca , Citi Simona , Lorenzi Davide , Poli Alessandro
Published: July 2002

Canine haemangiopericytoma (CHP) is a vascular neoplasm thought to be derived from pericytes. The histological pattern and immunohistochemical profile were studied in 31 CHPs. Twenty‐three subjects were followed for 2 years to evaluate the correlation among tumour location, histotype, immunostaining and outcome of the disease. Of the 31 CHPs examined, 20 exhibited a perivascular whorled pattern, 8 were storifom and 3 were epithelioid. All tumours were positive for vimentin and negative for cytokeratin, factor VIII‐related antigen, glial fibrillary acidic protein and S‐100 protein. Seventeen CHPs were positive for actin and nine co‐expressed desmin. Six CHPs were also positive for CD34 antigen. The panel of immunohistochemical markers used confirmed the vascular lineage of CHP and aided in the exclusion of other mesenchymal tumours. Of the 23 dogs submitted to follow‐up, 6 had recurrence or metastases of the primary tumour. The epithelioid pattern or a noncutaneous location were associated with a poorer prognosis.
Neonatal screening for haemoglobinopathies: the results of a 10‐year programme in an English Health Region
Authors: Almeida Antonio M. , Henthorn Joan S. , Davies Sally C.
Published: July 2002

Neonatal identification of sickle cell disease can significantly reduce mortality and morbidity during the first 5 years of life. During a 10‐year period, 414 801 neonates were screened by isoelectric focusing. The most common variants detected were haemoglobins S, C, D and E. Two hundred and fifty of the samples tested were homozygotes or compound heterozygotes, and 6554 samples were heterozygotes for the common variants. The gene frequencies in the population tested were calculated from this data for the most common variants. They were: S, 0·0057; C, 0·0014; DPunjab(Los Angeles), 0·0007; E, 0·0005. Additionally, 16 babies had beta thalassaemia major and 405 had rarer variants, of which six had never previously been described. Knowledge of the distribution of these inherited diseases is useful in healthcare planning and appropriate allocation of resources, while counselling targeted at appropriate couples enables informed parental choice and may prevent disease.
Post renal transplantation human herpesvirus 8‐associated lymphoproliferative disorder and Kaposi's sarcoma
Authors: Kapelushnik Joseph , Ariad Samuel , Benharroch Daniel , Landau Daniel , Moser Asher , Delsol Georges , Brousset Pierre
Published: July 2002

Post‐transplantation lymphoproliferative disorders (PTLDs) and Kaposi's sarcoma (KS) are immunosuppression‐related tumours developing in solid organ transplant patients. Although the Epstein‐Barr virus (EBV) is detected in the majority of the PTLDs during the first year after transplantation, the proportion of EBV‐negative PTLDs has increased in recent years. We report a case of a 17‐year‐old man who developed severe immune haemolytic anaemia, KS and human herpesvirus 8 (HHV‐8)‐associated, polymorphic‐type PTLD 9 months after allogeneic renal transplantation from his HHV‐8‐seropositive father. It is suggested that: (i) HHV‐8 may be associated with EBV‐negative, polymorphous‐type PTLD occurring less than 1 year after transplantation, and (ii) PTLD may be listed among other tumours, including KS, Castleman's disease and primary effusion lymphoma (PEL), that are related to HHV‐8 infection.
The effect of vaginal bleeding during pregnancy on preterm and small‐for‐gestational‐age births: US National Maternal and Infant Health Survey, 1988
Authors: Yang  , Savitz
Published: July 2002

We examined the effects of vaginal bleeding during pregnancy on preterm and small‐for‐gestational‐age (SGA) births using data from the 1988 US National Maternal and Infant Health Survey. We examined the severity of vaginal bleeding and separated the preterm births into subsets by the degree of prematurity (< 32, 32–33, 34–36 weeks’ gestation). We also evaluated associations stratified by race. Multiple logistic regression analysis showed that vaginal bleeding was associated with an increased risk of preterm birth, with a more pronounced elevated risk for preterm birth before 34 weeks’ gestation and a notably stronger association for more severe bleeding that occurred in both the first and the second half of pregnancy. Odds ratios, but not risk differences, for birth before 34 weeks’ gestation were greater for white women with vaginal bleeding than for black women. There was no association between vaginal bleeding during pregnancy and SGA births.
Kinetic properties of the glucose‐6‐phosphate and 6 phosphogluconate dehydrogenases from Corynebacterium glutamicum and their application for predicting pentose phosphate pathway flux in vivo
Authors: Moritz Bernd , Striegel Katharina , de Graaf Albert A. , Sahm Hermann
Published: July 2002

The glucose‐6‐phosphate (Glc6P) and 6‐phosphogluconate (6PG) dehydrogenases of the amino‐acid‐producing bacterium Corynebacterium glutamicum were purified to homogeneity and kinetically characterized. The Glc6P dehydrogenase was a heteromultimeric complex, which consists of Zwf and OpcA subunits. The product inhibition pattern of the Glc6P dehydrogenase was consistent with an ordered bi‐bi mechanism. The 6PG dehydrogenase was found to operate according to a Theorell–Chance ordered bi‐ter mechanism. Both enzymes were inhibited by NADPH and the 6PG dehydrogenase additionally by ATP, fructose 1,6‐bisphosphate (Fru1,6P2), d‐glyceraldehyde 3‐phosphate (Gra3P), erythrose 4‐phosphate and ribulose 5‐phosphate (Rib5P). The inhibition by NADPH was considered to be most important, with inhibition constants of around 25 µm for both enzymes.

Intracellular metabolite concentrations were determined in two isogenic strains of C. glutamicum with plasmid‐encoded NAD‐ and NADP‐dependent glutamate dehydrogenases. NADP+ and NADPH levels were between 130 µm and 290 µm, which is very much higher than the respective Km and Ki values. The Glc6P concentration was around 500 µm in both strains.

The in vivo fluxes through the oxidative part of the pentose phosphate pathway calculated on the basis of intracellular metabolite concentrations and the kinetic constants of the purified enzymes determined in vitro were in agreement with the same fluxes determined by NMR after 13C‐labelling. From the derived kinetic model thus validated, it is concluded that the oxidative pentose phosphate pathway in C. glutamicum is mainly regulated by the ratio of NADPH and NADP+ concentrations and the specific enzyme activities of both dehydrogenases.
Comparison of potential pathogenic traits of staphylococci that may contribute to corneal ulceration and inflammation
Authors: Wu P Z J , Zhu H , Thakur A , Willcox M D P
Published: July 2002

Staphylococcus epidermidis and Staphylococcus aureus are two of the commonest bacteria isolated from corneal ulcers. The aim of the current investigation was to determine the frequency of potentially pathogenic traits in the two staphylococcal species. Strains of both species, some isolated from eyes during active corneal inflammation, were screened for their ability to degrade a variety of proteins and hyaluronic acid and the production of cytotoxins. S. aureus produced more tissue‐destructive enzymes than the S. epidermidis. S. aureus strains more commonly synthesized the cytotoxin, α‐toxin. The production of elastase was more common among S. aureus strains isolated from ulcerative events. The production of α‐toxin was inversely correlated with isolation from keratitis. This study has demonstrated that S. aureus is better equipped with a range of potentially damaging enzymes and toxins than S. epidermidis and that S. aureus elastase may be involved in the production of corneal ulcers.
Long‐term results of intrarenal surgery for branched calculi: is such surgery still valid?
Authors: Rocco  , Casu  , Carmignani  , Trinchieri  , Mandressi  , Larcher  , Gadda
Published: July 2002

Objective

 To evaluate whether intrarenal surgery for branched calculi remains valid in the light of current new techniques, e.g. percutaneous nephrolithotomy and extracorporeal shockwave lithotripsy.

Patients and methods

 Between January 1978 and October 1984, 44 patients (24 male and 20 female, mean age 42.5 years, range 14–66) underwent complex surgery for large stones, requiring opening of the renal pelvis and a transparenchymal approach to the calices; 47 renal units were operated in 49 procedures. The evaluation before surgery included creatinine and blood nitrogen levels, blood pressure measurement, urine culture, abdominal plain X‐ray (44 patients), intravenous urography (42) and isotopic renography with renal scintigraphy (five). Renal lithiasis was categorized and all patients underwent extended pyelolithotomy with a transparenchymal approach, achieved by partial nephrectomy (six patients), radial paravascular nephrotomy (10), posterior lower nephrolithotomy (29), resection of the posterior segment (two), and posterior segmentotomy and reconstruction (2); 16 operations were performed under ischaemia. In October 1996, the patients were clinically evaluated by serum creatinine levels (42), urine cultures (42), abdominal plain X‐ray (42), IVU (34), isotopic renography (eight), renal ultrasonography (eight) and blood pressure measurement (44). The mean follow‐up was 14.8 years.

Results

 The major postoperative complications were; residual stones (six patients), fistula with ureteric stenosis (one, with a permanent nephrostomy), toxic temporary hepatic failure (one), femoral arterial embolism (one, resolved using a Fogarty catheter) and recurrent large stones (two, operated 1 and 5 years later). From 1984 to 1996, 19 patients had recurrent stones and two underwent dialysis. In October 1996, the renal function of 47 renal units was stable or normal in 36 (77%), reduced in seven (15%) and lost in four (8%); 24 patients were hypertensive (12 pre‐operatively), nine have urinary tract infection, three are positive for hepatitis B or C virus, and lithiasis has recurred in 15 renal units.

Conclusions

 Intrarenal surgery, conducted using modern anatomical guidelines, was an effective treatment for renal branched stones. The long‐term results are satisfactory after appropriate correction of the urinary tract, with the consequent prevention of stasis and chronic infection. The definitive comparison between surgical and combined endoscopic/extracorporeal methods will only become clear when there is a comparable follow‐up. Currently, surgery remains preferable in patients with giant calculi, a small pelvis and prevalent calyceal development.
Carbohydrate sources and glycaemic control in Type 1 diabetes mellitus
Authors: Buyken A. E. , Toeller M. , Heitkamp G. , Irsigler K. , Holler C. , Santeusanio F. , Stehle P. , Fuller J. H. , Group The Eurodiab Iddm Complications Study
Published: July 2002

Aims Little information is available on the relationship betweeen glycated haemoglobin levels and the source or amount of dietary carbohydrate. The present study compares the association of carbohydrate intake with HbA1c between European individuals with Type 1 diabetes mellitus injecting insulin once or twice per day and those with ≥ 3 daily injections.

Methods The relation of carbohydrate intake (total, cereal, fruit, vegetable, milk, and potato carbohydrate assessed by a 3‐day dietary record) to HbA1c was examined in 2084 patients (age 32.6 ± 10.2 years, duration of diabetes 14.8 ± 9.5 years) included in the EURODIAB Complications Study.

Results In both insulin injection regimens, an increased intake of total carbohydrate (% of energy) and a higher consumption of potato carbohydrates (g) were associated with higher levels of HbA1c, whereas an increased intake of vegetable carbohydrate (g) was inversely related to HbA1c. These tendencies were all more pronounced in persons with one or two daily insulin injections. Consumption of cereal and fruit carbohydrates (g) was not related to HbA1c, irrespective of the insulin injection regimen. A trend of HbA1c to increase with higher intakes of milk carbohydrate was confined to those with one or two insulin injections per day (test for interaction: P = 0.01).

Conclusions In particular, subjects with only 1 or 2 daily insulin injections per day should receive specific advice to correctly consider milk and potato carbohydrates. On the other hand, people with Type 1 diabetes may profit from a higher consumption of vegetable carbohydrates for their levels of HbA1c.
Assessment of fogging resistance of anti‐fog personal eye protection
Authors: Dain Stephen J. , Hoskin Annette K. , Winder Chris , Dingsdag Don P.
Published: July 2002

The propensity for occupational eye protectors to fog in warm and moist conditions is often offered as a reason by workers not to wear occupational eye protection even where mandatory eye protection areas have been specified. A study of eye protection practices in the New South Wales coal mining industry identified the number one issue in underground coal mine conditions as being fogging of eye safety wear. Conventional anti‐fog treatments and cleaners were considered by the miners as completely inadequate in these conditions. At the time of the study claims were being made for a new generation of lens treatments. These merited evaluation. Spectacles and goggles claimed to be fog resistant were obtained from manufacturers and suppliers and subjected to the test set out in BS EN 168:1995 and the compliance criterion of BS EN 166:1996. Some lenses claimed to be fog resistant failed the requirement, some new technology lenses showed arguably superior performance but failed the criterion of the standard. Modifications to the test procedure of BS EN 168 and acceptance criteria of BS EN 166 are proposed.
Naratriptan in the Prophylaxis of Cluster Headache
Authors: Loder Elizabeth
Published: July 2002

A 36‐year‐old man with cluster headache refractory to trials of standard prophylactic treatment and only partially responsive to parenteral sumatriptan and inhaled oxygen was admitted to an inpatient pain unit. The diagnosis of cluster headache was confirmed by direct observation of a typical attack.

Despite efforts at prophylaxis, the patient continued to experience three to four severe headaches per day. Attempts to control his headaches with scheduled parenteral dihydroergotamine were successful, but headaches recurred when the medication was tapered, and continuous or intermittent use of parenteral dihydroergotamine was not felt to be a practical option for the patient.

Naratriptan 2.5 mg twice daily completely abolished his headaches, which recurred when the medication was discontinued. No electrocardiographic or laboratory abnormalities were observed during treatment, and the patient reported no side effects.
Central Auditory Dysfunction May Precede the Onset of Clinical Dementia in People with Probable Alzheimer's Disease
Authors: Gates George A. , Beiser Alexa , Rees Thomas S. , D'Agostino Ralph B. , Wolf Philip A.
Published: July 2002

OBJECTIVES:

To document the prognostic significance of a central auditory speech‐processing deficit for the subsequent onset of probable Alzheimer's disease.

DESIGN:

Prospective cohort study.

SETTING:

Framingham Heart Study.

PARTICIPANTS:

Seven hundred forty dementia‐free volunteers from the Framingham Heart Study cohort with symmetric hearing thresholds at biennial examination 15 (1983–1985).

MEASUREMENTS:

The diagnosis of probable Alzheimer's disease was made prospectively using the National Institute of Neurological and Communicative Disorders and Stroke–Alzheimer's Disease Related Disorder Association criteria. A central auditory speech‐processing deficit was defined as a score of 50% of less correct on the Synthetic Sentence Identification with Ipsilateral Competing Message test in at least one ear with normal word recognition ability in both ears. Cox proportional hazards regression assessed the relationship between a central auditory speech‐processing deficit and the age at diagnosis of probable Alzheimer's disease.

RESULTS:

Forty subjects (5.4%) received a diagnosis of probable Alzheimer's disease during an average of 8.4 years (range 3–12) of follow‐up; seven (17.5%) of these had a central auditory speech‐processing deficit. The presence of a central auditory speech‐processing deficit had an age‐adjusted risk ratio for probable Alzheimer's disease of 10.8 (95% CI = 4.6–25.2), and the estimated risk ratio adjusted for age, gender, education level, apolipoprotein allele E4 presence, and hearing level was 23.3 (95% CI = 6.6–82.7). A central auditory speech‐processing deficit had a positive predictive value for subsequent probable Alzheimer's disease of 47% but the sensitivity was only 17.5%.

CONCLUSION:

Central auditory speech‐processing deficits may be an early manifestation of probable Alzheimer's disease and may precede the onset of dementia diagnosis by many years. J Am Geriatr Soc 50:482–488, 2002.
Advance Care Planning by Proxy for Residents of Long‐Term Care Facilities Who Lack Decision‐Making Capacity
Authors: Volicer Ladislav , Cantor Michael D. , Derse Arthur R. , Edwards Denise Murray , Prudhomme Angela M. , Gregory Dorothy C. Rasinski , Reagan James E. , Tulsky James A. , Fox Ellen , The National Ethics Committee of the Veterans Health Adminis
Published: July 2002

This report examines whether long‐term care facilities should implement policies and procedures to support advance care planning by proxy for residents who lack decision‐making capacity. The report focuses on advance care planning in the Department of Veterans Affairs. After reviewing clinical, legal, and ethical perspectives, the authors conclude that advance proxy planning is ethically sound and can improve patient care. However, because experience with advance proxy planning is still fairly limited, the authors do not recommend that a particular standardized approach be mandated at the national level. Instead, local facilities are advised to develop their own policies and then evaluate their effect. The report contains specific recommendations for the advance proxy planning process.
Recent and forgotten aspects of visceral pain
Authors: Giamberardino Maria Adele
Published: July 2002

Progress in the field of visceral pain research has been particularly rapid in recent years. Some aspects of the symptom that had previously been neglected for some time have now received a great deal of attention in both clinical and experimental studies. This regards, in particular, phenomena of hyperalgesia: (a) of visceral structures, because of local inflammatory/sensitizing processes (visceral hyperalgesia); (b) of areas of referred pain from viscera (referred somatic hyperalgesia from viscera); and (c) of a visceral structure, because of an algogenic process of another visceral domain (viscero‐visceral hyperalgesia). Clinical studies in patients have led to characterisation of subjective and objective symptoms of these phenomena. A number of studies in human volunteers (employing experimental procedures to stimulate and measure pain reactivity in both visceral structures and somatic areas of referral) have further increased the knowledge about modalities of generation of the various forms of hyperalgesia.

Animal experiments have improved understanding of pathophysiological mechanisms, mostly those underlying the referred hyperalgesia, with a number of findings supporting the notion of central changes at the basis of the phenomenon. An important aspect of laboratory experiments in recent years has been the setting up of animal models of visceral pain conditions closely mimicking a number of clinical pain states in patients. As a result, the outcome of experimental studies (electrophysiological, pharmacological, etc.) appears more directly applicable to the interpretation of the clinical reality.

Finally, in the context of laboratory studies, a novel trend of investigation is represented by genetic experiments, particularly those employing ‘knock‐out’ mice. These experiments, by generating animals lacking specific genes responsible for the production of various receptors implicated in pain transmission, have further contributed to the understanding of the generation of visceral pain symptoms. Although studies in this field are in their early stage, they seem particularly promising for a better understanding of the pathophysiology of visceral pain, and thus the establishment of more satisfying therapies in the future.
Growth Strategy and the Gradual Symbiotic Interactions of the LichenOchrolechia frigida
Authors: Gaßmann A. , Ott S.
Published: July 2002

Abstract:The symbiotic interactions in connection with the growth strategy of the crustose lichenOchrolechia frigida(Sw.) Lynge have been investigated and the flexibility of its life strategies is discussed. The lichen is an interesting model organism for the mutualistic adaptation of bionts to each other and to the habitat conditions.O. frigidaconsists of verruciform granules which contain both bionts, and spinules and an extensive prothallus which both generally contain no algae. The algal‐free stages seem to be capable of saprotrophic nutrition and hyphae penetrate cells and tissues of mosses, phanerogams and lichens. A variety of morphological and anatomical adaptations and a special type of reproductive biology are necessary to survive in harsh environments. But the overwhelming success ofO. frigidais based partly on the capability of the algal‐free mycobiont to colonize all plant substrates and its ability to use parasitic or at least saprotrophic ways of life to supplement its symbiotic nutrition. The environmental conditions obviously influence the growth form of the lichen. In habitats where the biomatter turnover is notoriously slow (e.g., in the Antarctic) saprotrophic nutrition will be limited and the lichen is mainly characterized by granules.
Stability of phase locking in coupled semiconductor laser arrays
Authors: Winful H. G. , Wang S. S.
Published: July 2002

It is shown that amplitude phase coupling (as described by the linewidth enhancement factor α) leads to unstable phase locking in semiconductor laser arrays with evanescent coupling.
Laser-driven chemical vapor deposition of platinum at atmospheric pressure and room temperature from C
pPt(CH3)3
Authors: Koplitz Lynn Vogel , Shuh David K. , Chen Y.-J. , Williams R. Stanley , Zink Jeffrey I.
Published: July 2002

Photolysis of CpPt(Me)3(Cp=η5-C5H5, Me=CH3) at room temperature and atmospheric pressure produces thin films and patterned structures of platinum metal on solid substrates. The platinum films are characterized by Auger electron spectroscopy, x-ray diffraction, and scanning electron microscopy. Substrates can also be prepatterned by laser irradiation and then developed into a shiny platinum deposit at a later time.
Hydrogen passivation of electrically active defects in diamond
Authors: Landstrass M. I. , Ravi K. V.
Published: July 2002

Subjecting natural diamond single crystals to the action of atomic hydrogen in a hydrogen plasma is shown to result in the passivation of interband states in the crystal resulting in a marked reduction in the resistivity to about 105 Ω cm from the expected high resistivity of∼1016 Ω cm. When the hydrogenated crystals are heat treated in a neutral ambient, the hydrogen can be expelled from the crystals, restoring the high resistivity. The behavior of natural diamond crystals, with respect to the effects of hydrogen, is shown to be similar to the behavior of diamond thin films synthesized by plasma-enhanced chemical vapor deposition techniques.
Scanning force microscopy using a simple low-noise interferometer
Authors: den Boef A. J.
Published: July 2002

A force microscope is described that can be used for high-resolution surface profiling and for observing magnetic domains. The microscope uses a Michelson interferometer to sense the vibration of a cantilever. The interferometer contains some straightforward processing to eliminate laser intensity noise. Some measuring results are presented that illustrate the performance of the microscope.
Flux creep characteristics in high-temperature superconductors
Authors: Zeldov E. , Amer N. M. , Koren G. , Gupta A. , McElfresh M. W. , Gambino R. J.
Published: July 2002

We describe the voltage-current characteristics of YBa2Cu3O7−δ epitaxial films within the flux creep model in a manner consistent with the resistive transition behavior. The magnitude of the activation energy, and its temperature and magnetic field dependences, are readily derived from the experimentally observed power law characteristics and show a (1−T/Tc)3/2 type of behavior near Tc. The activation energy is a nonlinear function of the current density and it enables the determination of the shape of the flux line potential well.
Novel Si1−xGex/Si heterojunction internal photoemission long-wavelength infrared detectors
Authors: Lin T. L. , Maserjian J.
Published: July 2002

A new approach to the design of a Si-based infrared detector is demonstrated, based on internal photoemission over a Si1−xGex/Si heterojunction barrier. The heterojunction internal photoemission device structure is grown by molecular beam epitaxy (MBE). The detector requires a degenerately doped p+-Si1−xGex layer for strong infrared absorption and photoresponse. Doping concentrations to 1020 cm−3 are achieved using boron from a HBO2 source during MBE growth of the Si1−xGex layers. The photoresponse of this device is tailorable, and most significantly, can be extended into the long-wavelength infrared regime by varying the Ge ratio x in the Si1−xGex layers. Results are obtained with x=0.2, 0.28, 0.3, and 0.4 on patterned Si (100) substrates. Photoresponse at wavelengths ranging from 2 to 10 μm is obtained with quantum efficiencies above ∼1% in these nonoptimized structures.
Arsenic precipitates and the semi-insulating properties of GaAs buffer layers grown by low-temperature molecular beam epitaxy
Authors: Warren A. C. , Woodall J. M. , Freeouf J. L. , Grischkowsky D. , McInturff D. T. , Melloch M. R. , Otsuka N.
Published: July 2002

Arsenic precipitates have been observed in GaAs low-temperature buffer layers (LTBLs) used as ‘‘substrates’’ for normal molecular beam epitaxy growth. Transmission electron microscopy has shown the arsenic precipitates to be hexagonal phase single crystals. The precipitates are about 6±4 nm in diameter with a density on the order of 1017 precipitates per cm3. The semi-insulating properties of the LTBL can be explained in terms of these arsenic precipitates acting as ‘‘buried’’ Schottky barriers with overlapping spherical depletion regions. The implications of these results on LTBL resistivity stability with respect to doping and anneal temperature will be discussed as will the possible role of arsenic precipitates in semi-insulating liquid-encapsulated Czochralski-grown bulk GaAs.
Internal stress and elasticity of synthetic diamond films
Authors: Berry B. S. , Pritchet W. C. , Cuomo J. J. , Guarnieri C. R. , Whitehair S. J.
Published: July 2002

The internal tensile stress in polycrystalline diamond films deposited on silicon substrates has been measured from 100 to 700 K by a vibrating-membrane method. The stress increases strongly with temperature, in a manner consistent with the elastic accommodation of the differential thermal strain between diamond and silicon. The results indicate that the films contain a tensile growth stress of about 500 MPa at the deposition temperature of 1123 K. Derived values of the biaxial elastic modulus fall in the range 730–850 GPa.