bluuebunny/crossref_metadata_2025 huggingface dataset:
Species status and population genetic structure of grapevine eriophyoid mites
Authors: Carew Melissa E. , Goodisman Micheal A. D. , Hoffmann Ary A.
Published: April 2004

Bud mite, blister mite (Colomerus vitis Pagenstecher), and rust mite (Calepitrimerus vitis Nalepa) (Acari: Eriophyoidae) are recognized grapevine pests. Much of the biology and ecology of these pests is poorly understood. We used two types of molecular markers to gain further insight into the breeding biology and population structure of these mites, using individuals collected from sites around south‐eastern Australia. Patterns of genetic variation observed using PCR‐RFLP of ITS 1 (Internal Transcribed Spacer 1) confirmed the separate species status of the rust mite, and resolved the species status of bud and blister mites, revealing two closely related but distinct species. Microsatellite markers revealed extensive genetic differentiation between bud mite populations and blister mite populations even at micro‐geographical levels, suggesting low movement in these species. The findings indicate that separate control strategies are needed against bud and blister mites, and that localized control strategies are likely to be effective given their limited dispersal.
Patterns of parasitism among conopid flies parasitizing bumblebees
Authors: Otterstatter Michael Christopher
Published: April 2004

The effects of host size and host species on the prevalence and fitness of conopid flies (Diptera: Conopidae) parasitizing bumblebees (Hymenoptera: Apidae) were investigated. Field data from nine sites across south‐western Alberta, Canada, showed that conopids parasitized, on average, 12.3% of workers and 3.5% of male bees. In general, bee mass was a better predictor of host use and conopid offspring size than bee species. Host mass could not, however, explain the very low prevalence of conopids in the long‐tongued bumblebee, Bombus californicus Smith, or in male bees in general. Conopids predominately infested bees of intermediate size, and as a result, occurred most commonly in the intermediately sized species, B. flavifrons Cresson. Host quality, in terms of conopid offspring size, increased as a non‐linear function of bee size. The results are discussed with respect to the impact of conopids on bumblebee populations, and the relation between host quality and patterns of host use.
Peripheral nerve regeneration in the absence of glial fibrillary acidic protein
Authors: Previtali SC , Dina G , Galizia G , Malaguti C , Amadio S , Del Carro U , Messing A , Quattrini A
Published: April 2004

Axonal loss is a consistent and undesirable event even in primary demyelinating neuropathies, and is responsible for most disabling and permanent deficits. In fact, in several peripheral neuropathies the physiological ability of nerve to regenerate is lost or dramatically reduced. Schwann cells play a central role in nerve regeneration and the laminin‐laminin receptor‐cytoskeleton pathway is fundamental to control numerous Schwann cell functions and Schwann cell‐axon interaction. A model to reproduce the events involved in axonal degeneration and regeneration is recapitulated in the stereotyped model of crush injury of the sciatic nerve in rodents. With this tool, we investigated the efficiency of nerve regeneration in mice lacking the glial fibrillary acidic protein (GFAP) intermediate filament, a Schwann cell specific cytoskeleton constituent. The peripheral nerves of GFAP null mice normally develop and function, and we did not detect gross differences in laminin and laminin receptor expression. However, after injury, the GFAP null mice showed a delay in the early phase of nerve regeneration.
Electrophysiological features in the distinction between hereditary demyelinating and chronic acquired demyelinating neuropathies
Authors: Poglio F , Tavella A , Ciaramitaro P , Prolasso I , Vercelli L , Mongini T , Palmucci L , Cocito D
Published: April 2004

We carried out an electrophysiological retrospective study in 55 patients with chronic demyelinating acquired and hereditary neuropathies. Alterations of motor nerve conduction velocities (MNCV), distal motor latencies (DML), conduction blocks (CB) and compound muscle action potential (CMAP) were compared, considering the whole number of nerves for each disease. MNCV, DML, CB and CMAP were considered suggestive of demyelination when meeting the American Academy of Neurology (AAN) criteria. Abnormally slow MNCV was found respectively in the 46% of all the CMTX female nerves studied, in the 56.5% of CMTX males, 84% of CMT1A, 74% CIDP and 70% of MAG‐PNP. Prolonged DML was observed in the 25% of the CMTX female nerves studied, in the 49.5% of CMTX males, 81% of CMT1A, 63% of CIDP and 71% of MAG‐PNP. Moreover, CB were quite often evidenced in CIDP and MAG‐PNP nerves (respectively in 48% and 29%) and rarely in hereditary neuropathies. Finally, we observed CMAP reduction in the 45% of all the CMTX female nerves studied, in the 50% of CMTX males, 63% of CMT1A, 49% of CIDP and 60% of MAG‐PNP. A well‐characterized pattern generally allows an electrophysiological distinction between CMT1A, CMTX males, MAG‐PNP on one side and CIDP and CMTX females on the other side. A clear electrodiagnostic distinction result is often hard between CMTX males and MAG‐PNP and between CIDP and CMTX females.
Experimental axonopathy induced by immunization with campylobacter jejuni lipopolysaccharide from a patient with guillain‐barré syndrome
Authors: Caporale CM , Capasso M , Lucani M , Gandolfi P , De Angelis MV , Di Muzio A , Caporale V , Uncini A
Published: April 2004

Campylobacter jejuni (C. jejunj) infection is the most common antecedent in the axonal variant of Guillain‐Barré syndrome (GBS). Antibodies against nerve gangliosides found in GBS patients recognize cross‐reactive epitopes in the lipopolysaccharide (LPS) of C. jejuni. This led to the molecular mimicry hypothesis of GBS. We immunized eleven rabbits with a LPS extracted from HS:19 C. jejuni strain isolated from a patient with GBS and complete Freund's adjuvant (CFA)(group I). In a second experiment we immunized seven rabbits with LPS, CFA and keyhole limpet hemocyanin (KLH)(group II). All group I rabbits developed high titers of anti‐LPS, anti‐GM1, anti‐GD1b antibodies and lower titers of anti‐GD1a. One rabbit, 50 days after initial inoculation, showed tremor and weakness. All rabbits of group II developed high titres of antiganglioside antibodies and six animals showed weakness 59–113 days after initial inoculation. Two rabbits died. Pathology showed mild to moderate, tendentially grouped, axonal degeneration in sciatic nerves of four out of five animals. Control rabbits of group I (immunized with CFA only) did not develop antibodies, controls of group II (immunized with CFA + KLH) developed low titers of IgG anti‐GM1. None developed neurological signs or showed axonal degeneration. C. jejuni LPS is a potent B‐cell stimulator capable to induce a strong antiganglioside response in rabbits. However, to induce the neuropathy is crucial to employ KLH, a glycoprotein known to stimulate both humoral and cellular responses. This animal model reproduces the pathogenetic process hypothesized in axonal GBS with antiganglioside antibodies post C. jejuni infection.
Idiopathic CIDP (I‐CIDP) and CIDP associated with diabetes mellitus or monoclonal gammopathy of undetermined significance have different clinical course and response to treatment
Authors: Jann S , Beretta S , Bramerio M
Published: April 2004

CIDP can occur with other systemic diseases such as diabetes mellitus (CIDP‐DM) and non‐malignant monoclonal gammopathy (CIDP‐MGUS). Whether I‐CIDP, CIDP‐DM and CIDP‐MGUS differ in clinical presentation, response to treatment and long‐term outcome is unclear, as well as the relationship of these concurrent diseases to CIDP. Eight patients with I‐CIDP, 16 patients with CIDP‐DM and 7 patients with CIDP‐MGUS were included in this study and sural nerve biopsies were taken. Clinical conditions were evaluated using a Neurologic Disability Scale (NDS) and a modified Rankin Scale (MRS). All patients were treated with at least 1 course of intravenous immunoglobulins (IVIg) at a dosage of 2 g/Kg administered over 5 days and classified as treatment responders or non responders according to clinical improvement. Improvement was defined as a decrease of 4 points in the NDS score. Patients were retreated in case of relapses. Relapse was defined as worsening after improvement with an increase of 4 points or more in NDS score. Sural nerve pathology was assessed on semithin sections. No differences were detected among the three groups according to age and sex. On neurologic examination the CIDP‐DM group had a significantly more severe disease based on the NDS and MRS score. In all the three groups there was an improvement after treatment but this is statistically significant only in the CIDP‐DM group. At the end of the follow‐up there is no difference in clinical conditions among the three groups but there is a significant difference according to the number of IVIg administrations and thus with the number of relapses. In conclusion CIDP‐DM is a more severe disease compared to the other 2 groups, but with a significant better response to IVIg and less number of relapses.
Painful diabetic neuropathy (pdn): a morphological study of capsaicin receptor distribution
Authors: Morbin M , Capobianco R , Borgna M , Lombardi R , Geppetti P , Davis JB , Pareyson D , Lauria G
Published: April 2004

Capsaicin receptor TRPV1 is a non‐selective ligand‐gated channel activated by different noxious stimuli. Previous studies suggested that an increased density of TRPV1 positive axons in the skin could be involved in the pathogenesis of neuropathic pain. To investigate the expression of TRPV1 in PDN patients, skin biopsies from 6 patients with PDN and 10 controls, and sural nerve biopsies from 2 patients with PDN and 2 controls were studied using the polyclonal anti‐human TRPV1 antibody. Skin nerve fibers widely expressed TRPV1 immunoreactivity. The density of TRPV1 positive dermal and intra‐epidermal nerve fibers (IENF) did not differ from that obtained using the PGP 9.5 antibody (the standard marker for IEFN recognition). Confocal analysis demonstrated that TRPV1 and anti unique‐tubulin‐1 antibody (TuJ1) co‐localized in all axons. In PDN patients IENF density was significantly reduced, but no difference in immunostaining was detectable using TRPV1, PGP 9.5 and TuJ1 antibodies. Sural nerve unmyelinated fibers and few small‐myelinated fibers were intensely stained by TRPV1. DPN patients disclosed a severe reduction in unmyelinated fiber density, but residual fibers were recognized by TRPV1. These data suggest that TRPV1 is widely expressed in skin and sural nerve unmyelinated axons, but its expression is not increased in PDN. Other mechanisms, such as changes in proximal axon or neuron excitability, are more likely involved in the pathogenesis of neuropathic pain in diabetic neuropathy.
Myelin thickenings in val 102/fs null mutation of MPZ gene
Authors: De Angelis MV , Capasso M , Anghiari C , Cavallaro T , Di Muzio A , Fabrizi GM , Uncini A
Published: April 2004

Myelin thickenings, abnormal myelin foldings and tomacula have been rarely described in CMT1B. In two unrelated patients of different age (patient 1: 29 years old; patient 2: 65 years old) with CMT1B and Val 102/fs null mutation of MPZ gene we performed morphometric analysis, teased fibers and ultrastructural examination of sural nerve. We found: 1) markedly decreased fiber density with prevalent loss of large diameter fibers (patient 1: 4419 fibers/mm2; patient 2: 1326 fibers/mm2); 2) evidence of de‐remyelination; and 3) paranodal and internodal myelin thickenings in virtually all fibers. Patient 1 has myelin thickenings measuring more than 50% of the fiber diameter in 14% of fibers and thickenings greater than 30% in 33% of fibers. Patients 2 presents myelin thickenings measuring more than 50% of fiber diameter in 23% of fibers and thickening greater than 30% in 49% of fibers. When considering the absolute measure of myelin thickenings and their number over 100 internodes, patient 1 presents 150 small myelin thickenings (<8 mm of diameter) whereas patient 2 has 57. The number of globules (8–12 mm of diameter) is 56 in patient 1 and 45 in patient 2. The number of myelin thickenings greater than 12 mm is 33 in patient 1 and 45 in patient 2. Ultrathin sections showed myelin infoldings, outfoldings and uncompacted myelin. CMT1B with a heterozygous null mutation of MPZ gene is characterized by abundant focal myelin thickenings. Similar findings have been described in the P0 deficient heterozygous mice.
Further evidence of genetic heterogeneity in autosomal dominant distal motor neuronopathy
Authors: Magariello A , Muglia M , Passamonti L , Bellesi M , Conforti FL , Mazzei R , Patitucci A , Gabriele AL , Sprovieri T , Peluso G , Caracciolo M , Medici E , Logullo F , Provinciali L , Quattrone A
Published: April 2004

Distal hereditary motor neuronopathy (distal HMN) is a genetically and clinically heterogeneous disorder. To date three loci have been identified on chromosomes 7p14, 9q34 and 12q24. We describe a four generation Italian family with distal HMN starting at around 30 years of age with weakness and atrophy of distal leg muscles and pyramidal features. We performed genetic linkage analysis with microsatellites on chromosomes 7p14, 9q34 and 12q24. Negative LOD scores excluded any evidence of linkage to the above‐mentioned chromosomes in the family. Moreover, because of pyramidal features in our patients, we performed the linkage analysis to all the known loci for autosomal dominant hereditary spastic paraparesis (ADHSP). The analysis was negative thus excluding that our patients were affected by a complicated form of ADHSP. These data further confirm a genetic heterogeneity within inherited motor neuronopathy disorders.
Multineuropathy in a patient with HBV infection, polyarteritis nodosa and celiac disease
Authors: Squintani G , Ferrari S , Refatti N , Capra F , Caramaschi P , Rizzuto N , Tonin P
Published: April 2004

A 53‐year‐old man came to our observation for impaired gait and painful paresthesia in his hands and feet. Three years before he suddenly presented tingling in his hands, followed, after a few months, by paresthesia in his feet, weakness of the right hand and foot and cutaneous erythema. Nearly one year after the onset, he presented left abducens nerve palsy that completely resolved in three months with steroid therapy. The patient's conditions progressively worsened and when he was admitted to our clinic the neurological examination revealed a stepping gait and severe muscular atrophy. Sensory abnormalities involved pin, light touch and vibration perception. In three years he had severe weight loss. Blood test revealed HBV infection and high levels of antibodies to transglutaminase, endomysium, and gliadin. EMG showed sensorimotor asymmetric axonal neuropathy. Nerve biopsy showed fiber loss, axonal degeneration with asymmetrical distribution and focal ischaemia. A duodenal biopsy was consistent with celiac disease. The patient was treated with high dose steroids, plasma exchange, immunoglobulin and lamivudine and began a gluten‐free diet. At discharge he could walk unassisted; sensory abnormalities were greatly reduced. One year later a new duodenal biopsy showed a complete resolution of the pathological abnormalities. Celiac disease, a chronic inflammatory intestinal disease whose pathogenesis involves a HLA DQ2‐DQ8 restricted T‐cell immune‐reaction, can be related to a higher risk of autoimmune disorders, such as insulin‐dependent diabetes or thyroid disease. We report the association of celiac disease, polyarteritis nodosa and HBV infection in a patient who developed a neuropathy and discuss the pathogenetic implications.
Solitary plexiform neurofibroma presenting as purely motor axonal cervical plexopathy
Authors: Terenghi F , Grimoldi N , Costa A , Nobile‐Orazio E
Published: April 2004

A 27‐year‐old male presented with three years of progressive weakness and atrophy in his right arm. He did not have sensory complaints or pain but occasional proximal arm dysesthesias. Neurological examination showed severe right shoulder girdle atrophy and proximal limb weakness affecting muscles supplied by the fifth and sixth cervical roots. Strength was normal distally in the right arm and in the other limbs. Deep tendon reflexes were normal. Sensation was normal. Laboratory studies showed increased creatine kinase levels. Anti‐GM1 IgM antibodies were not found. Electrodiagnostic studies were consistent with either focal motor neuronopathy or right brachial plexopathy involving the upper trunk. Nerve conduction studies did not show conduction blocks or slow conduction velocity. The CMAP amplitude of the right median nerve was normal. EMG showed chronic denervation and fibrillation potentials in paraspinal and arm muscles innervated by right C5–C6. MRI studies revealed markedly increased signal intensity on T2‐weighted images of the fifth and sixth right cervical roots and upper trunk of right plexus with contrast‐enhanced T1‐weighted images. A provisional diagnosis of motor axonal inflammatory plexopathy was made based on the purely motor focal deficit, increased creatine kinase levels and enhancing focal hypertrophic roots on MRI, as described in CIDP and MMN. The patient was treated with high dose IVIg 2 g/Kg over four days with no improvement. Two months later a biopsy of enlarged cervical root revealed a plexiform neurofibroma. The patient did not have a family history or other typical abnormalities of neurofibromatosis (NF1), including cafè‐au‐lait spots, skin fold freckling, Lisch nodules in the iris and bone dysplasia. Solitary plexiform neurofibroma may occur in patients without other stigmata of NF1 and should be considered in the differential diagnosis of purely motor focal inflammatory radiculoplexopathy.
New neurophysiological findings on skin receptors or intradermal nerve endings after repetitive capsaicin application
Authors: Aprile I , Stalberg E , Caliandro P , Pazzaglia C , Tonali P , Foschini M , Trotta E , Padua L
Published: April 2004

Background: The standard sensory nerve conduction studies evaluate only large myelinated fibres and its sensitivity may be low in early sensory polyneuropathy where only skin receptors or intradermal nerve endings are involved. During conventional sensory nerve conduction studies through surface electrodes, when we slowly increased the intensity of the stimulus, we occasionally observed a sensory response characterised by a particular morphology with two peaks (double peak potential). Some observations suggested that the first peak was due to stimulation of the nerve fibers and the second peak was due to the activation of the skin receptors or intradermal nerve endings. Objective: The aim of this study is to demonstrate that the second peak is due to activation of the receptors and epidermal nerve fibres. Previously, studies showed that repeated topical applications of capsaicin to human subjects resulted in progressive, almost complete, degeneration of receptors and epidermal nerve fibres. In the present study we report the effects of repeated topical applications of capsaicin to the fingertip of the human subjects on the double peak potential. Materials and Methods: Five‐healthy symptom‐free volunteers participated. Capsaicin cream (0,075%) was applied topically four times daily for 4–5 weeks to the fingertip of digit III (on the distal phalanx). Double peak evaluation and sensory tests were performed before treatment, at intervals during treatment and after capsaicin was discontinued. Results: The second peak obtained using submaximal anodal stimulation disappeared after repeated topical applications of capsaicin, and reappeared one month after interruption of topical application. Conclusions: The results of this study confirm our hypothesis about the neurophysiological meaning of the two peaks. The double peak potential can have a diagnostic role in the distal sensory involvement, especially in the early stage when the distal impairment of nerve endings cannot be detected by standard evaluation of sensory nerve conduction.
Mutations disrupting extracellular structure of MPZ cause early onset severe forms of CMT1B
Authors: Grandis M , Jain M , La Padula V , Balsamo J , Lilien J , Kamholz J , Schenone A , Shy ME
Published: April 2004

Missense mutations in myelin protein zero (MPZ), an important molecule for myelin compaction, cause inherited neuropathies collectively referred to as CMT1B. Depending on the mutation, phenotypes can be severe, or mild. To determine genotype‐phenotype correlations in CMT1B we evaluated patients from 11 different families seen in our clinic and 80 reported cases from the literature with respect to (1) how the mutation affected amino acids known to be critical for homotypic MPZ interactions; (2) whether the mutation affected the charge or hydrophobicity of an amino acid; (3) whether the mutation was likely to affect the secondary or tertiary structure of the MPZ, or (4) whether it affected evolutionarily conserved amino acids. We found that mutations that added a charged residue to the extracellular domain, introduced a cysteine or altered a conserved amino acid, caused a severe neuropathy. Mutation of an amino acid critical for cis or trans homotypic adhesion, however, had no obvious consequences on disease severity. We conclude that mutations which significantly disrupt the secondary or tertiary structure of MPZ are likely to cause severe, early onset neuropathies, whereas mutations which do not cause milder disease. Studies on how mutations disrupt protein trafficking and adhesion are underway.
Tryptophan recycling is responsible for the interferon‐γ resistance of Chlamydia psittaci GPIC in indoleamine dioxygenase‐expressing host cells
Authors: Wood Heidi , Roshick Christine , McClarty Grant
Published: April 2004

Comparative genomics indicates that vast differences in Chlamydia sp. host range and disease characteristics can be traced back to subtle variations in gene content within a region of the chromosome termed the plasticity zone. Genes required for tryptophan biosynthesis are located in the plasticity zone; however, the complement of genes encoded varies depending on the chlamydial species examined. Of the sequenced chlamydia genomes, Chlamydia psittaci GPIC contains the most complete tryptophan biosynthesis operon, encoding trpRDCFBA. Immediately downstream of the trp operon are genes encoding kynureninase and ribose phosphate pyrophosphokinase. Here, we show that, in GPIC, these genes are transcribed as a single transcript, the expression of which is regulated by tryptophan. Complementation analyses, using various mutant Escherichia coli isolates, indicate that the tryptophan biosynthesis, kynureninase and ribose phosphate pyrophosphokinase gene products are functional. Furthermore, growth of C. psittaci GPIC in HeLa cells, cultured in tryptophan‐free medium, could be rescued by the addition of anthranilate, kynurenine or indole. In total, our results indicate that this complement of genes enables GPIC to recycle tryptophan and thus accounts for the interferon‐γ resistant phenotype displayed in indoleamine‐2,3‐dioxygenase‐expressing host cells.
Effective production of marker‐free transgenic strawberry plants using inducible site‐specific recombination and a bifunctional selectable marker gene
Authors: Schaart Jan G. , Krens Frans A. , Pelgrom Koen T. B. , Mendes Odette , Rouwendal Gerard J. A.
Published: April 2004

Public concerns about the issue of the environmental safety of genetically modified plants have led to a demand for technologies allowing the production of transgenic plants without selectable (antibiotic resistance) markers. We describe the development of an effective transformation system for generating such marker‐free transgenic plants, without the need for repeated transformation or sexual crossing. This system combines an inducible site‐specific recombinase for the precise elimination of undesired, introduced DNA sequences with a bifunctional selectable marker gene used for the initial positive selection of transgenic tissue and subsequent negative selection for fully marker‐free plants. The described system can be generally applied to existing transformation protocols, and was tested in strawberry using a model vector in which site‐specific recombination leads to a functional combination of a cauliflower mosaic virus 35S promoter and a GUS encoding sequence, thereby enabling the histochemical monitoring of recombination events. Fully marker‐free transgenic strawberry plants were obtained following two different selection/regeneration strategies.
Comparative Study of the Effects of Ceftizoxime, Piperacillin, and Piperacillin-Tazobactam Concentrations on Antibacterial Activity and Selection of Antibiotic-Resistant Mutants of
Enterobacter cloacae
and
Bacteroides fragilis
In Vitro and In Vivo in Mixed-Infection Abscesses
Authors: Stearne Lorna E. T. , van Boxtel Doret , Lemmens Nicole , Goessens Wil H. F. , Mouton Johan W. , Gyssens Inge C.
Published: April 2004

The effects of ceftizoxime (CZX), piperacillin (PIP), and PIP-tazobactam (PT) concentrations on the antibacterial activity and selection of resistant mutants of
Bacteroides fragilis
and
Enterobacter cloacae
were investigated in vitro in a mixed-culture anaerobic time-kill study and in vivo in a mixed-infection abscess model. Mixed cultures were incubated for 24 h with 0.125 to 512 μg of CZX per ml or 0.125 to 2,048 μg of PIP or PT per ml. Mice were treated every 2 h for 24 h with CZX at 6 to 1,536 mg/kg/day or with PIP or PT at 24 to 6,144 mg/kg/day starting 30 min before inoculation with different
B. fragilis
-
E. cloacae
combinations. There was a good correlation between the in vitro and in vivo activities of the antibiotics and their MICs obtained with high inocula (10
8
CFU/ml). The respective 50% effective doses (milligrams per kilogram per day) with
B. fragilis
and
E. cloacae
22491 were 771 and 521 for CZX, 416 and 643 for PIP, and 85 and 554 for PT, and with the
B. fragilis
-
E. cloacae
032349 combination, they were 81 and 21 for CZX and 77 and 766 for PT. Resistant mutants of
E. cloacae
22491 were preferentially selected in vitro with 2 to 64 μg of CZX per ml and in vivo with CZX at 12 to 384 mg/kg/day. There was no preferential selection of CZX-resistant
B. fragilis
or
E. cloacae
032349. For CZX-resistant
E. cloacae
22491, we found a 16- to 512-fold increase in the MIC of CZX and increased MICs of other expanded-spectrum cephalosporins, owing in part to the production of a stably derepressed cephalosporinase. In vitro and in vivo, PT did not select resistant mutants of
E. cloacae
and
B. fragilis
. Results demonstrate the adverse microbiological outcome of choosing an expanded-spectrum cephalosporin like CZX for empirical treatment of mixed infections involving a susceptible
Enterobacter
strain.
Mechanisms of Azole Resistance in Petite Mutants of
Candida glabrata
Authors: Brun Sophie , Bergès Thierry , Poupard Pascal , Vauzelle-Moreau Carole , Renier Gilles , Chabasse Dominique , Bouchara Jean-Philippe
Published: April 2004

We previously showed that resistant colonies of
Candida glabrata
inside the azole inhibition zones had respiratory deficiency due to mutations in mitochondrial DNA. Here, we analyzed the mechanisms of azole resistance in petite mutants of
C. glabrata
obtained by exposure to fluconazole or induced by ethidium bromide. The respiratory deficiency of these mutants was confirmed by oxygraphy and flow cytometric analysis with rhodamine 123, and its mitochondrial origin was demonstrated by transmission electron microscopy and restriction endonuclease analysis of the mitochondrial DNA. Flow cytometry with rhodamine 6G suggested an increased drug efflux in mutant cells, which was further supported by Northern blot analysis of the expression of the
C. glabrata CDR1
(
CgCDR1
) and
CgCDR2
genes, encoding efflux pumps. Conversely, the expression of
CgERG11
, which encodes the azole target, was not affected by petite mutations, and no differences were seen in the sequence of this gene between parent isolates and mutants. Moreover, sterol analysis showed similar overall amount of sterols in parent and mutant cells, but quantitative modifications were observed in the mutants, with almost undetectable biosynthesis intermediates. Further analysis performed after separation of free sterols from steryl esters revealed a defect in sterol esterification in mutant cells, with free ergosterol representing 92% of the overall sterol content. Thus, resistance or decreased susceptibility to azoles in petite mutants of
C. glabrata
is associated with increased expression of
CgCDR1
and, to a lesser extent, of
CgCDR2
. In addition, the marked increase in free ergosterol content would explain their increased susceptibility to polyenes.
Novel Inhalational Murine Model of Invasive Pulmonary Aspergillosis
Authors: Sheppard Donald C. , Rieg Gunter , Chiang Lisa Y. , Filler Scott G. , Edwards John E. , Ibrahim Ashraf S.
Published: April 2004

We developed a novel model of invasive aspergillosis (IA) that recapitulates human disease. Mice were immunosuppressed with cyclophosphamide and cortisone acetate and then infected in an aerosol chamber. This procedure reproducibly delivered 1 × 10
3
to 3 × 10
3
conidia to the lungs. Lethal pulmonary IA developed over 2 weeks and was prevented by amphotericin B.
Sex-specific growth effects in protogynous hermaphrodites
Authors: Munday Philip L , Hodges Alyson L , Choat J Howard , Gust Nick
Published: April 2004

We demonstrate sex-specific decoupling of otolith growth and somatic growth in two species of protogynous parrotfishes, Scarus frenatus and Chlorurus sordidus. Otoliths of both species increased in size consistently through life, even though somatic growth rate decreased with age (age effect). Furthermore, in S. frenatus, otoliths from terminal males were smaller than otoliths from females, despite males being larger than females of the same age. This demonstrates the presence of a sex-specific growth effect, where otoliths of fast-growing individuals (males) are smaller than otoliths of slow-growing individuals (females). The sex-specific growth effect for S. frenatus was most pronounced during the early life history, which suggests that only the fastest-growing females change sex to male. A sex-specific growth effect was also evident in C. sordidus, although it was not statistically significant because of greater variation in the otolith size of terminal males of this species. Our results demonstrate that the relationship between otolith and somatic growth can vary dramatically between the sexes. This will make it difficult to back-calculate size at age in protogynous species, or to conduct sex-specific back-calculations in gonochoristic species, unless the precise relationship between otolith and somatic growth is known for each sex.
Unit of analysis in conventional trip generation modelling: an investigation
Authors: Badoe Daniel A , Chen Chin-Cheng
Published: April 2004

This paper examines the importance of the unit of analysis selected for trip generation modelling when the model estimation data are collected in a household travel survey. The paper reviews the literature on the arguments made for the use of the "individual" or the "household" as the unit of analysis in trip production modelling, and then through a statistical exposition it determines what should be the appropriate unit of analysis. An empirical test of the forecast performance of household- and person-trip generation models is conducted using data collected in a household-travel-behaviour survey in the Greater Toronto Area of Canada. The paper concludes that the household is theoretically the preferable analysis unit to use in trip production modelling when the model estimation data are collected in a household travel survey in which the household is the sampling unit. The empirical test indicates that household-trip generation models yield predictions of trips at the household and traffic zone level, respectively, that are marginally more accurate than those yielded by person-trip generation models.Key words: trip generation, travel demand forecasting, household trip generation, person trip generation, sampling unit, travel demand modeling, activity-based travel forecasting.
Environmental modulation of thepssTNOPgene expression inRhizobium leguminosarumbv.trifolii
Authors: Wielbo Jerzy , Mazur Andrzej , Król Jarosław E , Marczak Małgorzata , Skorupska Anna
Published: April 2004

Exopolysaccharide production by Rhizobium leguminosarum bv. trifolii is required for successful establishment of nitrogen-fixing symbiosis with clover (Trifolium pratense L.). Using plasmid-borne transcriptional fusions of promoters of pss genes with promoterless lacZ the effect of root exudate, phosphate, and ammonia on expression of pssT, pssN, pssO, and pssP genes in wild-type strain RtTA1 background was determined. A stimulating effect of these environmental factors on pssO and pssP gene expression was observed. The putative pssO gene promoter was determined to be a strong promoter within which the divergent nod-box element was identified. The pssO promoter was slightly inducible in a flavonoid-dependent manner in wild-type R. leguminosarum bv. trifolii strains RtTA1 and ANU843 and very weakly active in a mutant of strain ANU843 that lacks the regulatory nodD gene. The expression of pssO and pssP genes in planta was investigated using plasmid-borne pssO–gusA and pssP–gusA fusions under different phosphate availability to clover. The level of pssO–gusA fusion expression was shown to be dependent on phosphate concentration in the plant growth medium.Key words: Rhizobium leguminosarum, exopolysaccharide, nod box, transcriptional fusion.
DECOHERENCE IN HEISENBERG'S REPRESENTATION
Authors: BLANCHARD PHILIPPE , OLKIEWICZ ROBERT
Published: April 2004

Various physical effects resulting from environmental decoherence are discussed in the algebraic framework. An example of dynamical de-quantization of a quantum particle is considered.
BOSE–EINSTEIN STATISTICS IN A DISCRETE SPECTRUM TRAP
Authors: CELEGHINI ENRICO , RASETTI MARIO
Published: April 2004

A detailed description of the statistical properties of a system of bosons in a harmonic trap at low temperature, which is expected to bear on the process of BE condensation, is given resorting only to the basic postulates of Gibbs and Bose, without assuming equipartition nor continuum statistics. Below Tc such discrete spectrum theory predicts for the thermo-dynamical variables a behavior different from the continuum case. In particular a new critical temperature Td emerges where the specific heat exhibits a λ-like spike.
CLUSTERS IN SPIN GLASSES AND THE FRUSTRATED PERCOLATION MODEL
Authors: CONIGLIO ANTONIO
Published: April 2004

The basic cluster formalism which maps the Ising model into a correlated percolation model will be discussed. More recently the extension of the cluster approach to frustrated systems, like spin glasses, has lead to the definition of a new geometrical model, called frustrated percolation. The properties of this model will be reviewed.
NON-TRIVIAL BEHAVIOR OF THE LINEAR RESPONSE FUNCTION IN PHASE ORDERING KINETICS
Authors: CORBERI FEDERICO , FUSCO NICOLA , LIPPIELLO EUGENIO , ZANNETTI MARCO
Published: April 2004

Drawing from exact, approximate and numerical results an overview of the properties of the out of equilibrium response function in phase ordering kinetics is presented. Focusing on the zero field cooled magnetization, emphasis is on those features of this quantity which display non trivial behavior when relaxation proceeds by coarsening. Prominent among these is the dimensionality dependence of the scaling exponent aχ which leads to failure of the connection between static and dynamic properties at the lower dimensionality dL, where aχ=0. We also analyse the mean spherical model as an explicit example of a stochastic unstable system, for which the connection between statics and dynamics fails at all dimensionalities.
A KINETIC MODEL OF INTERFACE MOTION
Authors: MANZI GUIDO , MARRA ROSSANA
Published: April 2004

We study a kinetic model for a system of two species of particles interacting via a repulsive long range potential and with a reservoir at fixed temperature. The interaction between the particles is modeled by a Vlasov term and the thermal bath by a Fokker–Planck term. We show that in the diffusive and sharp interface limit the motion of the interfaces at low temperature is described by a Stefan problem or a Mullins–Sekerka motion, depending on the time scale.
STOCHASTIC LEARNING OF FRACTAL IMAGES
Authors: MORATO LAURA M. , SIRI PAOLA
Published: April 2004

Optimal compression and decompression of fractal images can be performed by out-of-equilibrium stochastic systems which exhibit a learning behaviour. We show how stochastic systems of this type are able to learn the structure of classical fractal images in a simple situation.
DECISION ANALYSIS USING IC-BAGS
Authors: CHAKRABARTY KANKANA
Published: April 2004

In this paper, we discuss the notion of IC-Bags as introduced by the author, some issues related to IC-Bag based systems and their application in decision analysis. Sometimes it is observed that the semi-structured or unstructured nature of the problems addressed by expert systems can be perceived as the cause for the inability to develop precise requirement specifications. IC-Bags can serve as a tool for building rule-based decision analysis systems which can deal with situations where the count of the objects are not necessarily fixed. We discuss the semi-structured specifications involving maximum and minimum numbers of applications related to the problem-oriented methodology for the integrated problems involving IC-Bags. In this context, the total bias factor and the confidence level of the knowledge base are considered.
TRANSITION METAL SULFIDES AND THE ORIGINS OF METABOLISM
Authors: Cody George D.
Published: April 2004

▪ Abstract  The history of the theory and experimental evidence that the natural catalytic and reactive qualities of transition metal sulfides are linked to primitive metabolism is reviewed. In the late 1980s, a hypothesis arose that proposed that transition metal sulfides (in particular pyrrhotite and pyrite) might play a significant role promoting abiotic organic chemistry. As an outgrowth of this hypothesis, elaborate theories were presented, including proposals for earliest life being structurally distinct from extant prokaryotic life. During the 1990s and into the twenty-first century, experimental evidence has emerged that supports certain aspects of these theories; in other cases, the experiments reveal chemistry that diverges significantly from that which was proposed theoretically. In either case, however, there is clear evidence that transition metal sulfide minerals exhibit catalytic qualities for the promotion of reactions that have obvious metabolic utility and, therefore, could have provided the primitive Earth with valuable biochemical intermediates.
Two Decades of Research on the Problem Solving Inventory
Authors: Suzuki Lisa A. , Ahluwalia Muninder K.
Published: April 2004

Heppner, Witty, and Dixon's review of 2 decades of research on the Problem Solving Inventory (PSI) provides highlights of more than 120 studies relating problem-solving appraisal to psychological adjustment, physical health, coping, and educational and vocational issues. Although clearly an impressive body of literature, the level of data reported is uneven with attention to effect sizes (e.g., correlations) and sample descriptors (e.g., race/ethnicity, n size, gender). Acknowledging the importance of the PSI and this major review, we provide commentary on the need for a meta-analysis and the continual expansion of research on the PSI with respect to diversity issues (i.e., race/ethnicity, gender).
Mechanistic Explanations in the Social Sciences
Authors: Rios Diego
Published: April 2004

Two new concepts have recently made their way into the theoretical market of the social sciences: the concept of mechanism and that of sociological machine. This article offers an analysis of the concept of mechanism and suggests that in itself it is insufficient to rebuild current practice in the social sciences. It then discusses the complementary notion of sociological machine to show that it allows us to go deeper into the solution to some of the problems that mechanisms were unable to solve. The article can be read as a contribution to the old debate concerning the role of mechanistic explanation in the social sciences.
The Revelation of Organizational Trauma
Authors: Kahn William A.
Published: April 2004

This article describes a process by which organizations and their units may experience trauma, which is revealed through dysfunctional patterns of individual, group, inter-group, and organizational behavior. I illustrate this process in the context of an action research project with a hospital’s surgical unit whose presenting symptoms involved the inability of staff members to work together effectively. The article concludes with a discussion of principles of movement that enable group and organization members to create patterns that get them unstuck in how they work and function.
Buckling of Composite Plates with U-Shaped Cutouts
Authors: Yazici Murat , Ozcan Resat , Ulku Sedat , Okur Irfan
Published: April 2004

The influence of cutout shape upon the buckling stability of multilayered rectangular epoxy plates reinforced by glass fiber, with different orientation angles is investigated. U-shaped cutouts are made on the long sides symmetrically. The investigated plates are simply supported on the loaded edges (i.e. short sides) and free on the unloaded edges. The plates without cutouts are examined theoretically to confirm experimental and Finite Element (FE) results. The FE and experimental results are found out for different U-shaped cutouts sizes. U-notch shape effects are examined depending on notch depth and notch root radius. According to results, the effect of notch depth is stronger than that of the notch root radius on buckling loads of plates. But, in some cases, although plates containing U-notch, no reduction is obtained in buckling loads.

Obtained results with experimental, theoretical, and FE are in good agreement with each other.
Crushing of Flat Graphite/Epoxy Laminates Using a Column Specimen
Authors: Fleming David C. , Nicot Frederic
Published: April 2004

Crush testing of flat composite laminates is achieved using a simple test specimen that permits improved observation of the development of crushing damage and hence better correlation with crush modeling efforts. Graphite/Epoxy specimens fabricated as two intersecting flat laminates are crushed under quasistatic conditions. Effective triggering of progressive crushing damage is difficult, though stable crushing is achieved using a conventional chamfering technique. Crushing results from the column specimens were comparable to specimens made with a similar material and lay-up and crushed in a plate crushing fixture. The specimen geometry permits direct observation of the evolution of damage in the laminate in the proximity of the free edges of the laminate, and thus offers the potential for assisting the validation of phenomenological finite element crush models that attempt to capture the splaying crushing mode typical of many composite systems under crushing loads.
Whose Security? State-Building and the ‘Emancipation’ of Women in Central Asia
Authors: Kennedy-Pipe Caroline
Published: April 2004

Part of the Critical Security Studies agenda is to understand what security means at different times and in different places. This article tells a story of how women in Soviet Central Asia were affected by political/security strategies adopted by Moscow. It focuses on the way in which the Kremlin attempted to use the emancipation of women as a strategy to mitigate the historic influence of Islam in the region and to build a secular and unified USSR. The story raises issues for Critical Security Studies in terms of the referents of security, especially the tensions which arise between the construction of state security and the place of women.
Civil Society and Global Responsibility: the Arms Trade and East Timor
Authors: Zelter Angie
Published: April 2004

This article describes the direct action and ensuing trial of the ‘Ploughshares Women’ who were acquitted by the Crown Court at Liverpool in 1996, having damaged a Hawk aircraft being sold by the British government to Indonesia. The women argued that the Hawk aircraft were being used as part of the Indonesian government’s campaign against East Timor, a country it was illegally occupying, and in which it was carrying out gross human rights abuses. The women persuaded the jury that by selling the aircraft to Indonesia the British government was in violation of domestic and international law as well as ‘simple humanity and love’. Direct action was said to have been necessary after the failure of groups to persuade the British government to stop resolving ethical dilemmas in favour of profit in their dealings with Indonesia. The article ends with a discussion of individual responsibility in relation to global problems, and urges readers to take seriously concepts of global responsibility and global citizenship, and working towards reconfiguring society and economics to serve human interests.
Assessing Political Influence in Complex Decision-Making: An Instrument Based on Triangulation
Authors: Arts Bas , Verschuren Piet
Published: April 2004

In the past decades substantial work has been done on the assessment of influence of stakeholders in political decision-making. However, its use may be difficult when the process to be investigated is highly complex. The EAR instrument to be presented here is a method for valid ordinal measurement of political influence in complex decision-making at various levels. This assessment is based on triangulation: (1) political players’ own perception of their influence; (2) other players’ perceptions of the influence brought to bear; and (3) a process analysis by the researcher. The application of the instrument is illustrated by a case regarding the political influence of global NGOs on the Climate Convention. The advantages and limitations of the EAR instrument are also discussed.
Death and Dependence: Current Controversies over the Selective Serotonin Reuptake Inhibitors
Authors: Nutt David J.
Published: April 2004

Recent years have seen a considerable media interest in the adverse effects of the selective serotonin reuptake inhibitors (SSRIs). This has led to claims that these antidepressants may lead to suicide and homicide and that they cause dependence or even addiction. Such claims have caused great concerns to many patients and have confused doctors in both primary care and psychiatric practice. In this article I review the basis of these claims and show that many seem to emerge from the misinterpretation of evidence and the use of imprecise definitions. Although the SSRIs are not free of problems they compare very favourably with other antidepressants and other classes of psychotropic drugs. There is no evidence they are addictive in the formal sense of leading to a drug dependence syndrome. Some suggestions on the way these issues can be more precisely defined and studied in future are given.