bluuebunny/crossref_metadata_2025 huggingface dataset:
Uterine compression sutures for postpartum bleeding with uterine atony
Authors: Ouahba J , Piketty M , Huel C , Azarian M , Feraud O , Luton D , Sibony O , Oury JF
Published: March 2007

Objective  To assess the efficacy of a new uterine compression suturing technique in reducing postpartum haemorrhage secondary to severe uterine atony.

Design  Retrospective study.

Setting  University hospital between December 2000 and March 2006.

Population  Twenty women with uterine atony and postpartum bleeding that did not react to usual medical management.

Methods  All these women underwent compression suturing of the uterus, in which the anterior and posterior walls of the uterus were attached so as to compress the uterus.

Main outcome measures  Arrest of the bleeding, complications and fertility.

Results  Uterine compression suturing was sufficient to stop the bleeding immediately in 95% of the women. None of the women developed complications related to the procedure. All the women recovered normal menstrual cycles. Since uterine compression suturing, eight women have tried to conceive and six (75%) have had a term delivery.

Conclusion  Uterine compression suturing is a simple conservative procedure to stop postpartum haemorrhage in the case of failure of the usual management. This surgical technique can be performed quickly and does not seem to decrease fertility.
LIGHT AND ELECTRON MICROSCOPE OBSERVATIONS OF ALGIROSPHAERA ROBUSTA (PRYMNESIOPHYCEAE)1
Authors: Probert Ian , Fresnel Jacqueline , Billard Chantal , Geisen Markus , Young Jeremy R.
Published: March 2007

The coccolithophore Algirosphaera robusta (Lohmann) R. E. Norris was isolated into laboratory culture for the first time. This species is of particular interest as the first deep photic coccolithophore to be cultured, the only member of the Rhabdosphaeraceae to have been successfully isolated, and the first coccolithophore with a coccolith structure including a complex disjunct central area to have been studied in detail. Observations on the culture strain supported the previous inference that the commonly recognized species A. robusta, A. oryza Schlauder, and A. quadricornu (J. Schiller) R. E. Norris are conspecific. However, A. meteora (Müller) R. E. Norris and A. cucullata (Lecal‐Schlauder) J. R. Young, Probert et Kleijne were recognized as discrete species. Coccolith rim formation in A. robusta follows the pattern of biomineralization documented in other heterococcoliths and was suggested to be universal. However, the prominent central hood had a unique ultrastructure and appeared to be formed by a distinctively different biomineralization mode. We suggest that this can provide a key to reinterpreting homology in coccolith structure and that this species is a promising target for comparative biochemical and genomic studies of biomineralization. In terms of cell ultrastructure, A. robusta exhibited marked similarities to Syracosphaera pulchra Lohmann, and a close evolutionary relationship between the families Rhabdosphaeraceae and Syracosphaeraceae is suggested.
1 From a State of War to Perpetual Peace
Authors: Demenchonok Edward
Published: March 2007

Abstract.  This essay examines current debates in political philosophy regarding the problems of war and peace and of human rights protection. Two contrasting approaches are analyzed: one represented by “democratic peace” theories, and the other by the movement for a cosmopolitan order. At the heart of both approaches are conflicting interpretations of Kant's political philosophy, especially his project of “perpetual peace.” An analysis of M. Doyle's recent conception of “liberal democratic peace” shows the flaws in his justification of the tendency of liberal states to be war‐prone toward nonliberal states. Alternatively, the development of Kant's ideas in the theories of “discourse ethics” (K. O. Apel and J. Habermas) and “cosmopolitan democracy” confirms the relevance of Kant's cosmopolitan ideal to current discussions about peace and human rights. The analysis also affirms that the true solution to the problems of securing peace and protecting human rights can only be achieved by peaceful means, based on international law with the United Nations as its legitimate political representation.
3 Rethinking Global Justice from the Perspective of All Living Nature and What Difference it Makes
Authors: Sterba James P.
Published: March 2007

Abstract.  I begin this chapter with an account of what is deserved in human ethics, an ethics that assumes without argument that only humans, or rational agents, count morally. I then take up the question of whether nonhuman living beings are also deserving, and I answer it in the affirmative. Having established that all individual living beings, as well as ecosystems, are deserving, I go on to establish what it is that they deserve and then compare the requirements of global justice when only humans are taken into account with the requirements of global justice when all living beings are taken into account. I argue that the more adequate global justice that takes into account all living beings imposes some additional obligations on us that are absent from a less defensible human‐centered global justice, but not as many as one might initially think.
10 The Subject of Freedom at the End of History: Socialism Beyond Humanism
Authors: Sanbonmatsu John
Published: March 2007

Abstract.  The postmodernist turn in theory left the status of humanism in some doubt. This chapter argues that a recuperation of a specifically socialist humanism is both possible and desirable, but only by overcoming the anthropocentrism of radical humanism. Renaissance and Enlightenment conceptions of the subject were rooted in an untenable dichotomy between the human and the animal, in ways that vitiated the idea and ideal of universal freedom. By conflating subjectivity as such with human subjectivity, humanism created a diremption in the world that placed the knower (human consciousness) on one side, and the merely known (objectified Nature) on the other. Marxism and socialist humanism reproduced this error in ways that have undermined the socialist vision of universal emancipation, misconstrued the nature of the subject, and overlooked the significance of human domination of other animals. The author advocates a new approach, what he calls metahumanism, to affirm a “two‐sided” freedom in which the liberation of other animals from human oppression, and the emancipation of ourselves as animals—that is, the restoration of the sensual dimension of existence, free sexual expression, and valorization of the labor and love of the body—would become central features of a new movement for civil and cultural reform.
Randomized Comparison of J‐Shaped Atrial Leads with and without Active Fixation Mechanism
Authors: LURIA DAVID M. , FEINBERG MICHA S. , GUREVITZ OSNAT T. , BAR‐LEV DAVID S. , GRANIT CHAVA , TANAMI NECHEMIA , ELDAR MICHAEL , GLIKSON MICHAEL
Published: March 2007

Background: In this prospective, randomized, controlled study, we compared the performance of J‐shaped active fixation (AF) atrial leads with J‐shaped passive fixation (PF) leads, over a 1‐year follow‐up period.

Methods: A total of 200 consecutive patients were prospectively randomized for implantation with a Medtronic 5568 AF lead model (n = 103; Minneapolis, MN, USA) versus a Medtronic 5592 PF model (n = 97), and all lead‐related measurements and complications were recorded over one year.

Results: All leads were successfully implanted with a nonsignificant difference in crossover rate to the alternative lead due to failed implantation (1 in the AF and 4 in the PF group, P = NS). Fluoroscopy time during implantation procedure was significantly shorter in the PF group (2.1 ± 3.6 vs 3.3 ± 4.5 minute, P < 0.05). Pacing thresholds during implantation were significantly lower in patients with PF leads (0.7 ± 0.3 V vs 0.9 ± 0.3 V, P < 0.001) and this difference persisted at 1‐year follow‐up (0.8 ± 0.6 V vs 1.3 ± 0.9 V in PF and AF leads respectively, P < 0.05). Lead‐related complications occurred in PF and AF with similar frequency (4% and 9% respectively, P = 0.2). However, pericardial complications occurred only in the AF group (6 cases, P = 0.01). Lead dislodgement was observed in only two cases—both in the PF group (P = 0.3).

Conclusion: Both types of J‐shaped atrial leads had reasonable performance. PF leads required shorter fluoroscopy time for implantation, demonstrated a better pacing threshold over a 1‐year follow‐up period and had no pericardial complications, while AF lead implantation was complicated by pericardial irritation and/or effusion in 6% cases (P = 0.01).
Cryptococcosis—a review of 13 autopsy cases from a 54‐year period in a large hospital
Authors: BENEŠOVÁ P. , BUCHTA V. , CERMAN J. , ŽÁ P.
Published: March 2007

From 1952 to 2005, 13 cases of cryptococcosis confirmed by postmortem examination were diagnosed in autopsy material from the University Hospital in Hradec Králové, the Czech Republic. Histologically, Cryptococcus was found in multiple organs (brain and spinal cord, lungs, lymph nodes, spleen, bone marrow, liver, kidneys and adrenal glands). The lungs and CNS were the organs most often involved. Only in two cases was the diagnosis of cryptococcal infection established during the patient's lifetime, in both presenting clinically as meningitis, with positive result of CSF cultivation. Data and issues of diagnostics and treatment of cryptococcosis are discussed.
Human papillomavirus infection and tumours of the anal canal: correlation of histology, PCR detection in paraffin sections and serology
Authors: TACHEZY R. , JIRASEK T. , SALAKOVA M. , LUDVIKOVA V. , KUBECOVA M. , HORAK L. , MANDYS V. , HAMSIKOVA E.
Published: March 2007

Human papillomavirus infection is an important etiological factor in squamous cell carcinoma of the anus (SCCA). Different histological variants of anal carcinomas displaying squamous differentiation, previously classified as separate tumours, were recently reclassified as SCCA by the WHO. In our recent study the presence of HPV was detected by PCR in biopsy specimens of 42 different anal tumours, including SCCA and its histological variants (n=22), adenocarcinomas (n=5), tubulovillous adenomas (n=5) and anal condylomas (n=10). HR HPV16 (high risk – HR) was detected in 18 of SCCA specimens (81.8%). All histological variants, i.e. tumours with basaloid, squamous and mixed histological patterns, were represented among the HPV‐positive cancers. Four tumours (18.2%) were HPV negative. Low‐risk (LR) HPV types were not detected within the SCCA group. HPV16 was identified in one adenocarcinoma, while four cases were HPV negative. Two adenomas showed presence of HPV16; one showed simultaneous positivity for HPV33. The remaining three tumours were HPV negative. Seven anal condylomas (70%) were LR HPV 6 and/or 11 positive, while three were HPV negative. The presence of HR HPV types was not observed in anal condylomas. Our results provide further evidence in support of the etiological role of HR HPV infection in the development of SCCA regardless of its histological appearance.
Extragenital subcutaneous cellular angiofibroma
Authors: VAL‐BERNAL J. FERNANDO , RUBIO SUSANA , GARIJO M. FRANCISCA , GONZÁLEZ‐VELA M. CARMEN
Published: March 2007

Cellular angiofibroma (CAF) is a rare distinctive mesenchymal neoplasm that occurs almost exclusively in the genital area. We report the case of a 38‐year‐old woman who presented with an asymptomatic subcutaneous mass, 3.5 cm in diameter, located in the left hypochondrium, which had progressively enlarged during the previous 6 months. The lesion was completely excised. No recurrence was observed 3 months after the excision. A review of the literature—and including the present report—revealed five cases (three men and two women) with location outside the urogenital tract. Mean age was 57 (range 38–78) years; mean 41 years for women and 68 years for men. Average tumor size was 9 (range 3.5–25) cm; mean 5 cm for women and 12 cm for men. Tumors were located in the superficial soft tissue of the trunk, except for one case in the retroperitoneum. Mean follow‐up was 29 (range 3–102) months, and no patient developed recurrence or metastasis. Extragenital CAF, except for location, shows similar clinicopathological features to genital CAF. Simple tumorectomy appears to be adequate treatment. Morphologically, CAF is closely related to spindle cell lipoma.
Soft tissue healing at titanium implants coated with type I collagen. An experimental study in dogs
Authors: Welander M. , Abrahamsson I. , Linder E. , Liljenberg B. , Berglundh T.
Published: March 2007

Objective: To analyse the soft tissue healing at titanium implants coated with type 1 collagen.

Material and methods: Six dogs were used. The mandibular pre‐molars and the three anterior maxillary pre‐molars were extracted. Three months later mucoperiosteal flaps were raised and two test and two control implants were installed (3i® TG Osseotite®3.75 × 10 and 2.8 mm transmucosal collar). The test implants were coated with a purified porcine type I collagen. Cover screws were placed and flaps were sutured. The sutures were removed 2 weeks later and a plaque‐control programme was initiated. Another 2 weeks later, the procedure was repeated in the contra‐lateral mandibular region. Four weeks after the second implant surgery, biopsies were obtained and prepared for histological examination.

Results/Conclusion: The vertical dimensions of the epithelial and connective tissue components as well as the composition of the connective tissue portion facing the implant were similar at collagen‐coated and uncoated implants after 4 and 8 weeks of healing. It is suggested that soft tissue healing to implants coated with type I collagen was similar to that at non‐coated titanium implants and that no adverse reactions to the collagen‐coated implants occurred.
Activation of crystalline cellulose to cellulose IIII results in efficient hydrolysis by cellobiohydrolase
Authors: Igarashi Kiyohiko , Wada Masahisa , Samejima Masahiro
Published: March 2007

The crystalline polymorphic form of cellulose (cellulose Iα‐rich) of the green alga, Cladophora, was converted into cellulose IIII and Iβ by supercritical ammonium and hydrothermal treatments, respectively, and the hydrolytic rate and the adsorption of Trichoderma viride cellobiohydrolase I (Cel7A) on these products were evaluated by a novel analysis based on the surface density of the enzyme. Cellobiose production from cellulose IIII was more than 5 times higher than that from cellulose I. However, the amount of enzyme adsorbed on cellulose IIII was less than twice that on cellulose I, and the specific activity of the adsorbed enzyme for cellulose IIII was more than 3 times higher than that for cellulose I. When cellulose IIII was converted into cellulose Iβ by hydrothermal treatment, cellobiose production was dramatically decreased, although no significant change was observed in enzyme adsorption. This clearly indicates that the enhanced hydrolysis of cellulose IIII is related to the structure of the crystalline polymorph. Thus, supercritical ammonium treatment activates crystalline cellulose for hydrolysis by cellobiohydrolase.
The Male Sexual Quotient: A Brief, Self-Administered Questionnaire to Assess Male Sexual Satisfaction
Authors: Abdo Carmita H.N.
Published: March 2007

Introduction

Sexual satisfaction is an important aspect of overall life satisfaction. The Male Sexual Quotient (MSQ) was designed to provide a versatile, user-friendly instrument to measure various aspects of male sexual function and satisfaction.

Aim

Assess responses to the MSQ in men with sexual dysfunction (SD).

Methods

Items for inclusion in the MSQ were developed through interviewing 612 randomly recruited men in São Paulo, Brazil, about factors considered to influence sexual quality of life. Validation of the MSQ was conducted in two phases in men with and without SD.

Main Outcome Measure

The correlation between patients’ total MSQ score and scores on the Sexual Health Inventory for Men (SHIM).

Results

The resulting MSQ questionnaire contains 10 items that address sexual function and satisfaction and is scored on a 100-point scale, with higher scores indicating greater sexual function and satisfaction with such function. Patients’ scores on the MSQ were positively correlated with scores on the SHIM (r = 0.86; P < 0.0001). Scores on MSQ item 8, which assesses ejaculatory control, indicated that 46% of patients may have premature ejaculation (PE). The mean time for patients to complete the MSQ was 11 minutes.

Conclusion

The MSQ is a brief, comprehensive, and easily self-administered tool designed to help men identify aspects of their sexual experience that could be improved through partner dialogue, physician consultation, and appropriate treatment. MSQ scores correlated well with SHIM scores, and scores were inversely related to the severity of erectile dysfunction or PE and other male SDs. These preliminary findings suggest that the MSQ possesses good convergent validity. Nearly half of men reported problems with ejaculatory control, indicating an association between PE and other SD. Further validation of the MSQ in a double-blind trial is needed. The MSQ may aid in decision making for the treatment of SD.
Hydromineral neuroendocrinology: mechanism of sensing sodium levels in the mammalian brain
Authors: Noda Masaharu
Published: March 2007

Dehydration causes an increase in the sodium (Na) concentration and osmolarity of body fluids. For Na homeostasis of the body, control of Na and water intake and excretion are of prime importance. Although the circumventricular organs (CVOs) were suggested to be involved in body‐fluid homeostasis, the system for sensing Na levels within the brain, which is responsible for the control of Na‐ and water‐intake behaviour, has long been an enigma. Nax is an atypical sodium channel that is assumed to be a descendant of the voltage‐gated sodium channel family. Our studies on the Nax‐gene‐targeting (Nax−/−) mouse revealed that Nax channels are localized to the CVOs and serve as a sodium‐level sensor of body fluids. As the first step to understand the cellular mechanism by which the information sensed by Nax channels is reflected in the activity of the organs, we dissected the subcellular distribution of Nax. Double‐immunostaining and immuno‐electron microscopic analyses revealed that Nax is exclusively localized to perineuronal lamellate processes extending from ependymal cells and astrocytes in the organs. In addition, glial cells isolated from the subfornical organ were sensitive to an increase in the extracellular sodium level, as analysed by an ion‐imaging method. These results suggest that glial cells bearing Nax channels are the first to sense a physiological increase in the level of sodium in body fluids, and regulate the neural activity of the CVOs by enveloping neurons. Close communication between inexcitable glial cells and excitable neural cells thus appears to be the basis of the central control of salt homeostasis.
Development of a Feedback Linearization Technique for Parametrically Excited Nonlinear Systems via Normal Forms
Authors: Zhang Yandong , Sinha S. C.
Published: March 2007

The problem of designing controllers for nonlinear time periodic systems via feedback linearization is addressed. The idea is to find proper coordinate transformations and state feedback under which the original system can be (exactly or approximately) transformed into a linear time periodic control system. Then a controller can be designed to guarantee the stability of the system. Our approach is designed to achieve local control of nonlinear systems with periodic coefficients desired to be driven either to a periodic orbit or to a fixed point. The system equations are represented by a quasi-linear system containing nonlinear monomials with periodic coefficients. Using near identity transformations and normal form theory, the original close loop problem is approximately transformed into a linear time periodic system with unknown gains. Then by using a symbolic computation method, the Floquet multipliers are placed in the desired locations in order to determine the control gains. We also give the sufficient conditions under which the system is feedback linearizable up to the rth order.
Does nature convert mass into energy?
Authors: Baierlein Ralph
Published: March 2007

First I provide some history of how the equation E=mc2 arose, establish what “mass” means in the context of this relation, and present some aspects of how the relation can be understood. Then I address the question, Does E=mc2 mean that one can “convert mass into energy” and vice versa?
Experiments on subtractive color mixing with a spectrophotometer
Authors: Gilbert P. U. P. A , Haeberli Willy
Published: March 2007

We describe experiments on color mixing suitable for undergraduate nonscience majors. A commercial spectrophotometer is used to study the spectra of light sources, combinations of color filters, and mixtures of acrylic paints. Special emphasis is placed on teaching the fundamentals of subtractive color mixing and the complex processes that occur in mixing pigments.
Role of Homoserine Transacetylase as a New Target for Antifungal Agents
Authors: Nazi Ishac , Scott Adam , Sham Anita , Rossi Laura , Williamson Peter R. , Kronstad James W. , Wright Gerard D.
Published: March 2007

Microbial amino acid biosynthesis is a proven yet underexploited target of antibiotics. The biosynthesis of methionine in particular has been shown to be susceptible to small-molecule inhibition in fungi. The first committed step in Met biosynthesis is the acylation of homoserine (Hse) by the enzyme homoserine transacetylase (HTA). We have identified the
MET2
gene of
Cryptococcus neoformans
H99 that encodes HTA (CnHTA) by complementation of an
Escherichia coli metA
mutant that lacks the gene encoding homoserine transsuccinylase (HTS). We cloned, expressed, and purified CnHTA and determined its steady-state kinetic parameters for the acetylation of
L
-Hse by acetyl coenzyme A. We next constructed a
MET2
mutant in
C. neoformans
H99 and tested its growth behavior in Met-deficient media, confirming the expected Met auxotrophy. Furthermore, we used this mutant in a mouse inhalation model of infection and determined that
MET2
is required for virulence. This makes fungal HTA a viable target for new antibiotic discovery. We screened a 1,000-compound library of small molecules for HTA inhibitors and report the identification of the first inhibitor of fungal HTA. This work validates HTA as an attractive drug-susceptible target for new antifungal agent design.
The Microbial Community Structure in Petroleum-Contaminated Sediments Corresponds to Geophysical Signatures
Authors: Allen Jonathan P. , Atekwana Estella A. , Atekwana Eliot A. , Duris Joseph W. , Werkema D. Dale , Rossbach Silvia
Published: March 2007

The interdependence between geoelectrical signatures at underground petroleum plumes and the structures of subsurface microbial communities was investigated. For sediments contaminated with light non-aqueous-phase liquids, anomalous high conductivity values have been observed. Vertical changes in the geoelectrical properties of the sediments were concomitant with significant changes in the microbial community structures as determined by the construction and evaluation of 16S rRNA gene libraries. DNA sequencing of clones from four 16S rRNA gene libraries from different depths of a contaminated field site and two libraries from an uncontaminated background site revealed spatial heterogeneity in the microbial community structures. Correspondence analysis showed that the presence of distinct microbial populations, including the various hydrocarbon-degrading, syntrophic, sulfate-reducing, and dissimilatory-iron-reducing populations, was a contributing factor to the elevated geoelectrical measurements. Thus, through their growth and metabolic activities, microbial populations that have adapted to the use of petroleum as a carbon source can strongly influence their geophysical surroundings. Since changes in the geophysical properties of contaminated sediments parallel changes in the microbial community compositions, it is suggested that geoelectrical measurements can be a cost-efficient tool to guide microbiological sampling for microbial ecology studies during the monitoring of natural or engineered bioremediation processes.
Flagellin Diversity in
Clostridium botulinum
Groups I and II: a New Strategy for Strain Identification
Authors: Paul Catherine J. , Twine Susan M. , Tam Kevin J. , Mullen James A. , Kelly John F. , Austin John W. , Logan Susan M.
Published: March 2007

Strains of
Clostridium botulinum
are traditionally identified by botulinum neurotoxin type; however, identification of an additional target for typing would improve differentiation. Isolation of flagellar filaments and analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) showed that
C. botulinum
produced multiple flagellin proteins. Nano-liquid chromatography-tandem mass spectrometry (nLC-MS/MS) analysis of in-gel tryptic digests identified peptides in all flagellin bands that matched two homologous tandem flagellin genes identified in the
C. botulinum
Hall A genome. Designated
flaA1
and
flaA2
, these open reading frames encode the major structural flagellins of
C. botulinum
. Colony PCR and sequencing of
flaA1/A2
variable regions classified 80 environmental and clinical strains into group I or group II and clustered isolates into 12 flagellar types. Flagellar type was distinct from neurotoxin type, and epidemiologically related isolates clustered together. Sequencing a larger PCR product, obtained during amplification of
flaA1/A2
from type E strain Bennett identified a second flagellin gene,
flaB
. LC-MS analysis confirmed that
flaB
encoded a large type E-specific flagellin protein, and the predicted molecular mass for FlaB matched that observed by SDS-PAGE. In contrast, the molecular mass of FlaA was 2 to 12 kDa larger than the mass predicted by the
flaA1/A2
sequence of a given strain, suggesting that FlaA is posttranslationally modified. While identification of FlaB, and the observation by SDS-PAGE of different masses of the FlaA proteins, showed the flagellin proteins of
C. botulinum
to be diverse, the presence of the
flaA1/A2
gene in all strains examined facilitates single locus sequence typing of
C. botulinum
using the flagellin variable region.
Diversity of Ca
2+
-Induced Morphology Revealed by Morphological Phenotyping of Ca
2+
-Sensitive Mutants of
Saccharomyces cerevisiae
Authors: Ohnuki Shinsuke , Nogami Satoru , Kanai Hanako , Hirata Dai , Nakatani Yoichiro , Morishita Shinichi , Ohya Yoshikazu
Published: March 2007

Yeast cell morphology can be treated as a quantitative trait using the image processing software CalMorph. In the present study, we investigated Ca
2+
-induced morphological changes in Ca
2+
-sensitive (
cls
) mutants of
Saccharomyces cerevisiae
, based on the discovery that the characteristic Ca
2+
-induced morphological changes in the Ca
2+
-sensitive mutant
zds1
reflect changes in the Ca
2+
signaling-mediated cell cycle control pathway. By applying hierarchical cluster analysis to the quantitative morphological data of 58
cls
mutants, 31 of these mutants were classified into seven classes based on morphological similarities. The patterns of morphological change induced by Ca
2+
in one class differed from those of another class. Based on the results obtained using versatile methods for phenotypic analysis, we conclude that a high concentration of Ca
2+
exerts a wide variety of effects on yeast and that there are multiple Ca
2+
-regulatory pathways that are distinct from the Zds1p-related pathway.
The Pathogenic Fungus
Cryptococcus neoformans
Expresses Two Functional GDP-Mannose Transporters with Distinct Expression Patterns and Roles in Capsule Synthesis
Authors: Cottrell Tricia R. , Griffith Cara L. , Liu Hong , Nenninger Ashley A. , Doering Tamara L.
Published: March 2007

Cryptococcus neoformans
is a fungal pathogen that is responsible for life-threatening disease, particularly in the context of compromised immunity. This organism makes extensive use of mannose in constructing its cell wall, glycoproteins, and glycolipids. Mannose also comprises up to two-thirds of the main cryptococcal virulence factor, a polysaccharide capsule that surrounds the cell. The glycosyltransfer reactions that generate cellular carbohydrate structures usually require activated donors such as nucleotide sugars. GDP-mannose, the mannose donor, is produced in the cytosol by the sequential actions of phosphomannose isomerase, phosphomannomutase, and GDP-mannose pyrophosphorylase. However, most mannose-containing glycoconjugates are synthesized within intracellular organelles. This topological separation necessitates a specific transport mechanism to move this key precursor across biological membranes to the appropriate site for biosynthetic reactions. We have discovered two GDP-mannose transporters in
C. neoformans
, in contrast to the single such protein reported previously for other fungi. Biochemical studies of each protein expressed in
Saccharomyces cerevisiae
show that both are functional, with similar kinetics and substrate specificities. Microarray experiments indicate that the two proteins Gmt1 and Gmt2 are transcribed with distinct patterns of expression in response to variations in growth conditions. Additionally, deletion of the
GMT1
gene yields cells with small capsules and a defect in capsule induction, while deletion of
GMT2
does not alter the capsule. We suggest that
C. neoformans
produces two GDP-mannose transporters to satisfy its enormous need for mannose utilization in glycan synthesis. Furthermore, we propose that the two proteins have distinct biological roles. This is supported by the different expression patterns of
GMT1
and
GMT2
in response to environmental stimuli and the dissimilar phenotypes that result when each gene is deleted.
Candida albicans
Rho-Type GTPase-Encoding Genes Required for Polarized Cell Growth and Cell Separation
Authors: Dünkler Alexander , Wendland Jürgen
Published: March 2007

Rho proteins are essential regulators of morphogenesis in eukaryotic cells. In this report, we investigate the role of two previously uncharacterized Rho proteins, encoded by the
Candida albicans RHO3
(Ca
RHO3
) and Ca
CRL1/
Ca
RHO4
genes. The Ca
RHO3
gene was found to contain one intron. Promoter shutdown experiments using a
MET3
promoter-controlled
RHO3
revealed a strong cell polarity defect and a partially depolarized actin cytoskeleton. Hyphal growth after promoter shutdown was abolished in
rho3
mutants even in the presence of a constitutively active
ras1
(
G13V
) allele, and existing germ tubes became swollen. Deletion of
C. albicans RHO4
indicated that it is a nonessential gene and that
rho4
mutants were phenotypically different from
rho3
. Two distinct phenotypes of
rho4
cells were elongated cell morphology and an unexpected cell separation defect generating chains of cells. Colony morphology of
crl1/rho4
resulted in a growth-dependent smooth (long cell cycle length) or wrinkled (short cell cycle length) phenotype. This phenotype was additionally dependent on the
rho4
cell separation defect and was also found in a Ca
cht3
chitinase mutant that shows a strong cytokinesis defect. The overexpression of the endoglucanase encoding the
ENG1
gene, but not
CHT3
, suppressed the cell separation defect of
crl1/rho4
but could not suppress the cell elongation phenotype.
C. albicans
Crl1/Rho4 and Bnr1 both localize to septal sites in yeast and hyphal cells but not to the hyphal tip. Deletion of
RHO4
and
BNR1
produced similar morphological phenotypes. Based on the localization of Rho4 and on the
rho4
mutant phenotype, we propose a model in which Rho4p may function as a regulator of cell polarity, breaking the initial axis of polarity found during early bud growth to promote the construction of a septum.
Complement Receptor 3 and Toll-Like Receptor 4 Act Sequentially in Uptake and Intracellular Killing of UnopsonizedSalmonella entericaSerovar Typhimurium by Human Neutrophils
Authors: van Bruggen Robin , Zweers Debby , van Diepen Angela , van Dissel Jaap T. , Roos Dirk , Verhoeven Arthur J. , Kuijpers Taco W.
Published: March 2007

The uptake and subsequent killing ofSalmonella entericaserovar Typhimurium by human neutrophils was studied. In particular, two pattern recognition receptors, complement receptor 3 (CR3) and Toll-like receptor 4 (TLR4), were found to be essential for the efficient uptake and activation, respectively, of the NADPH oxidase. The uptake ofSalmonellawas almost completely inhibited by various monoclonal antibodies against CR3, and neutrophils from a patient with leukocyte adhesion deficiency type 1, which lack CR3, showed almost no uptake ofSalmonella. A lipopolysaccharide (LPS) mutant strain ofSalmonellawas used to show that the expression of full-length, wild-type, or so-called smooth LPS is important for the efficient killing of intracellularSalmonella. Infection with wild-type-LPS-expressingSalmonellaresulted in the generation of reactive oxygen species (ROS) in TLR4-decorated,Salmonella-containing vacuoles, whereas ROS were not induced by an LPS mutant strain. In addition, the recognition ofSalmonellaby neutrophils, leading to ROS production, was shown to be intracellular, as determined by priming experiments with intact bacteria under conditions where the bacterium is not taken up. Finally, the generation of ROS in the wild-type-Salmonella-infected neutrophils was largely inhibited by the action of a TLR4-blocking, cell-permeable peptide, showing that signaling by this receptor from theSalmonella-containing vacuole is essential for the activation of the NADPH oxidase. In sum, our data identify the sequential recognition of unopsonizedSalmonellastrains by CR3 and TLR4 as essential events in the efficient uptake and killing of this intracellular pathogen.
Murine Aerosol Challenge Model of Anthrax
Authors: Loving Crystal L. , Kennett Mary , Lee Gloria M. , Grippe Vanessa K. , Merkel Tod J.
Published: March 2007

The availability of relevant and useful animal models is critical for progress in the development of effective vaccines and therapeutics. The infection of rabbits and non-human primates with fully virulentBacillus anthracisspores provides two excellent models of anthrax disease. However, the high cost of procuring and housing these animals and the specialized facilities required to deliver fully virulent spores limit their practical use in early stages of product development. Conversely, the small size and low cost associated with using mice makes this animal model more practical for conducting experiments in which large numbers of animals are required. In addition, the availability of knockout strains and well-characterized immunological reagents makes it possible to perform studies in mice that cannot be performed easily in other species. Although we, along with others, have used the mouse aerosol challenge model to examine the outcome ofB. anthracisinfection, a detailed characterization of the disease is lacking. The current study utilizes a murine aerosol challenge model to investigate disease progression, innate cytokine responses, and histological changes during the course of anthrax after challenge with aerosolized spores. Our results show that anthrax disease progression in a complement-deficient mouse after challenge with aerosolized Sterne spores is similar to that described for other species, including rabbits and non-human primates, challenged with fully virulentB. anthracis. Thus, the murine aerosol challenge model is both useful and relevant and provides a means to further investigate the host response and mechanisms ofB. anthracispathogenesis.
Integrated Response to Inducers by Communication between a Catabolic Pathway and Its Regulatory System
Authors: Martínez-Pérez Olga , López-Sánchez Aroa , Reyes-Ramírez Francisca , Floriano Belén , Santero Eduardo
Published: March 2007

Efficient gene regulation of metabolic pathways implies that the profile of molecules inducing the pathway matches that of the molecules that are metabolized. Gratuitous induction, a well-known phenomenon in catabolic pathways, is the consequence of differences in the substrate and inducer profiles. This phenomenon is particularly evident in pathways for biodegradation of organic contaminants that can be induced by a variety of molecules similar to the real substrates. Analysis of the regulation of tetralin biodegradation genes in mutant strains with mutations that affect each component of the initial dioxygenase enzymatic complex indicated that the response of the regulatory system to potential inducers is altered differently depending on the mutated component. Based on the expression phenotypes of a number of single or double mutants, we propose a model that represents an unprecedented way of communication between a catabolic pathway and its regulatory system to prevent efficient induction by a molecule that is not a real substrate. This communication allows a better fit of the substrate and inducer profiles, thus minimizing gratuitous induction, without a requirement for optimal coevolution to match the specificity of catabolic enzymes and their regulatory systems. Modulation of the regulatory system in this way not only provides a more appropriate response to potential inducers recognized by the regulatory system but also may properly adjust the levels of gene expression to the substrate availability.
Degradation of Alkyl Methyl Ketones by
Pseudomonas veronii
MEK700
Authors: Onaca Christina , Kieninger Martin , Engesser Karl-H. , Altenbuchner Josef
Published: March 2007

Pseudomonas veronii
MEK700 was isolated from a biotrickling filter cleaning 2-butanone-loaded waste air. The strain is able to grow on 2-butanone and 2-hexanol. The genes for degradation of short chain alkyl methyl ketones were identified by transposon mutagenesis using a newly designed transposon, mini-Tn
5495
, and cloned in
Escherichia coli
. DNA sequence analysis of a 15-kb fragment revealed three genes involved in methyl ketone degradation. The deduced amino acid sequence of the first gene,
mekA
, had high similarity to Baeyer-Villiger monooxygenases; the protein of the second gene,
mekB
, had similarity to homoserine acetyltransferases; the third gene,
mekR
, encoded a putative transcriptional activator of the AraC/XylS family. The three genes were located between two gene groups: one comprising a putative phosphoenolpyruvate synthase and glycogen synthase, and the other eight genes for the subunits of an ATPase. Inactivation of
mekA
and
mekB
by insertion of the mini-transposon abolished growth of
P. veronii
MEK700 on 2-butanone and 2-hexanol. The involvement of
mekR
in methyl ketone degradation was observed by heterologous expression of
mekA
and
mekB
in
Pseudomonas putida
. A fragment containing
mekA
and
mekB
on a plasmid was not sufficient to allow
P. putida
KT2440 to grow on 2-butanone. Not until all three genes were assembled in the recombinant
P. putida
was it able to use 2-butanone as carbon source. The Baeyer-Villiger monooxygenase activity of MekA was clearly demonstrated by incubating a
mekB
transposon insertion mutant of
P. veronii
with 2-butanone. Hereby, ethyl acetate was accumulated. To our knowledge, this is the first time that ethyl acetate by gas chromatographic analysis has been definitely demonstrated to be an intermediate of MEK degradation. The
mekB
-encoded protein was heterologously expressed in
E. coli
and purified by immobilized metal affinity chromatography. The protein exhibited high esterase activity towards short chain esters like ethyl acetate and 4-nitrophenyl acetate.
Expression Analysis of Multiple
dnaK
Genes in the Cyanobacterium
Synechococcus elongatus
PCC 7942
Authors: Sato Masumi , Nimura-Matsune Kaori , Watanabe Satoru , Chibazakura Taku , Yoshikawa Hirofumi
Published: March 2007

We analyzed the stress responses of three
dnaK
homologues (
dnaK1
,
dnaK2
, and
dnaK3
) in the cyanobacterium
Synechococcus elongatus
PCC 7942. A reporter assay showed that under stress conditions the expression of only the
dnaK2
gene was induced, suggesting a functional assignment of these homologues. RNA blot hybridization indicated a typical stress response of
dnaK2
to heat and high-light stress. Primer extension mapping showed that
dnaK2
was transcribed from similar sites under various stress conditions. Although no known sequence motif was detected in the upstream region, a 20-bp sequence element was highly conserved in
dnaK2
; it was essential not only for the stress induction but also for the basal expression of
dnaK2
. The ubiquitous upstream localization of this element in each heat shock gene suggests its important role in the cyanobacterial stress response.
Defining Genomic Islands and Uropathogen-Specific Genes in Uropathogenic
Escherichia coli
Authors: Lloyd Amanda L. , Rasko David A. , Mobley Harry L. T.
Published: March 2007

Uropathogenic
Escherichia coli
(UPEC) strains are responsible for the majority of uncomplicated urinary tract infections, which can present clinically as cystitis or pyelonephritis. UPEC strain CFT073, isolated from the blood of a patient with acute pyelonephritis, was most cytotoxic and most virulent in mice among our strain collection. Based on the genome sequence of CFT073, microarrays were utilized in comparative genomic hybridization (CGH) analysis of a panel of uropathogenic and fecal/commensal
E. coli
isolates. Genomic DNA from seven UPEC (three pyelonephritis and four cystitis) isolates and three fecal/commensal strains, including K-12 MG1655, was hybridized to the CFT073 microarray. The CFT073 genome contains 5,379 genes; CGH analysis revealed that 2,820 (52.4%) of these genes were common to all 11
E. coli
strains, yet only 173 UPEC-specific genes were found by CGH to be present in all UPEC strains but in none of the fecal/commensal strains. When the sequences of three additional sequenced UPEC strains (UTI89, 536, and F11) and a commensal strain (HS) were added to the analysis, 131 genes present in all UPEC strains but in no fecal/commensal strains were identified. Seven previously unrecognized genomic islands (>30 kb) were delineated by CGH in addition to the three known pathogenicity islands. These genomic islands comprise 672 kb of the 5,231-kb (12.8%) genome, demonstrating the importance of horizontal transfer for UPEC and the mosaic structure of the genome. UPEC strains contain a greater number of iron acquisition systems than do fecal/commensal strains, which is reflective of the adaptation to the iron-limiting urinary tract environment. Each strain displayed distinct differences in the number and type of known virulence factors. The large number of hypothetical genes in the CFT073 genome, especially those shown to be UPEC specific, strongly suggests that many urovirulence factors remain uncharacterized.
Error-Prone DNA Repair System in EnteroaggregativeEscherichia coliIdentified by Subtractive Hybridization
Authors: Joo Lucy M. , Macfarlane-Smith Louissa R. , Okeke Iruka N.
Published: March 2007

EnteroaggregativeEscherichia coli(EAEC) are etiologic agents of diarrhea. The EAEC category is heterogeneous, but most in-depth experimentation has focused on prototypical strain, 042. We hypothesized that 60A, another EAEC strain, might posses virulence or fitness genes that 042 does not have. Through subtractive hybridization we identified 60A-specific sequences, including loci present in otherE. coliand phage DNA. One locus thus identified wasimpB, a LexA repressed error-prone DNA repair gene that has been identified in plasmids from other enteric organisms and which we detected in 21 of 34 EAEC strains. An isogenic 60AimpBmutant showed decreased survival and mutagenesis after exposure to UV, as well as bile salt exposure, compared to the wild-type strain, and these phenotypes could be complemented in trans. The EAEC strain 60Aimpoperon differs structurally from previously described homologs. A cryptic gene,impC, present in otherimpoperons, is absent from 60A. In addition, transcription ofimpABin strain 60A occurs from a promoter that is dissimilar to the previously describedimpCpromoter but is still triggered by UV-mediated damage. In strain 60A theimpABand the aggregative adherence fimbriae I (AAF/I)-encoding genes are on the same large plasmid, and the 60A version of the operon is predominantly seen in AAF/I-positive EAEC. SupplementaryimpSOS-inducible error-prone repair systems are common among EAEC even though they are absent in prototypical strain 042.
TraY and Integration Host Factor
oriT
Binding Sites and F Conjugal Transfer: Sequence Variations, but Not Altered Spacing, Are Tolerated
Authors: Williams Sarah L. , Schildbach Joel F.
Published: March 2007

Bacterial conjugation is the process by which a single strand of a conjugative plasmid is transferred from donor to recipient. For F plasmid, TraI, a relaxase or nickase, binds a single plasmid DNA strand at its specific origin of transfer (
oriT
) binding site,
sbi
, and cleaves at a site called
nic
. In vitro studies suggest TraI is recruited to
sbi
by its accessory proteins, TraY and integration host factor (IHF). TraY and IHF bind conserved
oriT
sites
sbyA
and
ihfA
, respectively, and bend DNA. The resulting conformational changes may propagate to
nic
, generating the single-stranded region that TraI can bind. Previous deletion studies performed by others showed transfer efficiency of a plasmid containing F
oriT
decreased progressively as increasingly longer segments, ultimately containing both
sbyA
and
ihfA
, were deleted. Here we describe our efforts to more precisely define the role of
sbyA
and
ihfA
by examining the effects of multiple base substitutions at
sbyA
and
ihfA
on binding and plasmid mobilization. While we observed significant decreases in in vitro DNA-binding affinities, we saw little effect on plasmid mobilization even when
sbyA
and
ihfA
variants were combined. In contrast, when half or full helical turns were inserted between the relaxosome protein-binding sites, mobilization was dramatically reduced, in some cases below the detectable limit of the assay. These results are consistent with TraY and IHF recognizing
sbyA
and
ihfA
with limited sequence specificity and with relaxosome proteins requiring proper spacing and orientation with respect to each other.
A Novel Fur- and Iron-Regulated Small RNA, NrrF, Is Required for Indirect Fur-Mediated Regulation of the
sdhA
and
sdhC
Genes in
Neisseria meningitidis
Authors: Mellin J. R. , Goswami Sulip , Grogan Susan , Tjaden Brian , Genco Caroline A.
Published: March 2007

Iron is both essential for bacterial growth and toxic at higher concentrations; thus, iron homeostasis is tightly regulated. In
Neisseria meningitidis
the majority of iron-responsive gene regulation is mediated by the ferric uptake regulator protein (Fur), a protein classically defined as a transcriptional repressor. Recently, however, microarray studies have identified a number of genes in
N. meningitidis
that are iron and Fur activated, demonstrating a new role for Fur as a transcriptional activator. Since Fur has been shown to indirectly activate gene transcription through the repression of small regulatory RNA molecules in other organisms, we hypothesized that a similar mechanism could account for Fur-dependent, iron-activated gene transcription in
N. meningitidis
. In this study, we used a bioinformatics approach to screen for the presence of Fur-regulated small RNA molecules in
N. meningitidis
MC58. This screen identified one small RNA, herein named NrrF (for neisserial regulatory RNA responsive to iron [Fe]), which was demonstrated to be both iron responsive and Fur regulated and which has a well-conserved orthologue in
N. gonorrhoeae
. In addition, this screen identified a number of other likely, novel small RNA transcripts. Lastly, we utilized a new bioinformatics approach to predict regulatory targets of the NrrF small RNA. This analysis led to the identification of the
sdhA
and
sdhC
genes, which were subsequently demonstrated to be under NrrF regulation in an
nrrF
mutant. This study is the first report of small RNAs in
N. meningitidis
and the first to use a bioinformatics approach to identify, a priori, regulatory targets of a small RNA.