bluuebunny/crossref_metadata_2025_split huggingface dataset:
A slipped‐mispairing mutation in AgrA of laboratory strains and clinical isolates results in delayed activation of agr and failure to translate δ‐ and α‐haemolysins
Authors: Traber Katrina , Novick Richard 
Published: January 2006

Summaryagr is a global regulator of staphylococcal virulence and other accessory gene functions, especially including the haemolysins. Lack of haemolysin production therefore generally represents a defect in agr function. An example of this is Staphylococcus aureus strain RN4220, a widely used laboratory strain that carries a nitrosoguanidine (MNNG)‐induced mutation enabling it to accept DNA from Escherichia coli and other bacteria. We show here that the non‐haemolytic phenotype of RN4220 is caused by an extra A residue in a run of seven As at the 3′ end of agrA (agrA‐8A). This causes a frameshift that results in the addition of three amino acyl residues to the C‐terminal end of the protein. The 8A mutation does not inactivate the agr locus, but rather delays agr activation by 2–3 h, which results in failure to translate α‐ and δ‐haemolysins, and hence, in a non‐haemolytic phenotype. This mutation turned out not to be an adventitious consequence of MNNG mutagenesis, but rather had arisen in RN450, the immediate parent of RN4220. RN450 had become haemolytically heterogeneous in storage, and its non‐haemolytic variants had the 8A mutation. The same mutation was also identified in a clinical isolate in which a non‐haemolytic variant had arisen during the course of infection. Haemolytic activity in the mutant laboratory strains could be restored by the addition of auto‐inducing peptide (AIP) early in growth, indicating that delayed production of RNAIII is responsible for the failure to translate α‐ and δ‐haemolysins. Discovery of the 8A mutation has revealed the basis of the dissociation between agr activity and the non‐haemolytic phenotype of RN4220, and has solved the long‐standing mystery of the variable non‐haemolytic phenotype of its immediate parent, RN450. The occurrence of this mutation in a clinical isolate indicates that it is not simply a laboratory phenomenon, and may represent a naturally occurring mechanism for the modulation of agr activity.
Impacts of applied Sclerotinia sclerotiorum on the dynamics of a Cirsium arvense population
Authors: BOURDÔT G W , HURRELL G A , SAVILLE D J , LEATHWICK D M 
Published: January 2006

SummaryA field experiment was conducted from October 1992 to March 1997 in a sheep‐grazed pasture in Canterbury, New Zealand, to determine the effects of the fungus Sclerotinia sclerotiorum on the long‐term dynamics of a population of Cirsium arvense. The pathogen was applied in mid‐spring either once or in three consecutive years when the C. arvense shoots were vegetative rosettes, using a granular, mycelium‐on‐wheat preparation that lodged on the C. arvense leaves, stems and in the leaf axils. The single application caused disease in the C. arvense that was confined to the application year. The disease resulted in a temporary (17 months) reduction in population size through initial mortalities among treated shoots and resultant reductions in root growth, adventitious root bud, subterranean shoot and, subsequently, aerial shoot population sizes. The soil seedbank was 80% lower in the treated plots than in the control plots in the first year. Seedlings were never found. The annually repeated application of S. sclerotiorum did not result in the expected continuing decline in the C. arvense population relative to the control population.
Spectral discrimination of Ridolfia segetum and sunflower as affected by phenological stage
Authors: PEÑA‐BARRAGÁN J M , LÓPEZ‐GRANADOS F , JURADO‐EXPÓSITO M , GARCÍA‐TORRES L 
Published: January 2006

Summary Ridolfia segetum is an umbelliferous weed frequent and abundant in sunflower crops in the Mediterranean basin. Field research was conducted to evaluate the potential of hyperspectral and multispectral reflectance and five vegetation indices in the visible to near infrared spectral range, for discriminating bare soil, sunflower and R. segetum at different phenological stages. This was a preliminary step for mapping R. segetum patches in sunflower using remote sensing for herbicide application decisions. Reflectance data were collected at three sampling dates (mid‐May, mid‐June and mid‐July, corresponding to vegetative‐early reproductive, flowering and senescent phenological stages respectively) using a handheld field spectroradiometer. Differences observed in hyperspectral reflectance curves were statistically significant within and between crop and weed phenological stages depending on sampling date, which facilitates their discrimination. Statistically significant differences in the multispectral and vegetation indices analysis showed that it is also possible to distinguish any of the classes studied. Our study provides some information for constructing the spectral libraries of sunflower and R. segetum in which the different phenological stages co‐existing in the field were considered. Hyperspectral and multispectral results suggest that mapping R. segetum patches in sunflower is feasible using airborne hyperspectral sensors, and high‐resolution satellite imagery or aerial photography, respectively, taking into account specific timeframes.
Response to flooding intensity in Elytrigia repens, E. intermedia (Poaceae: Triticeae) and their hybrid
Authors: MAHELKA V 
Published: January 2006

SummaryResponse to flooding intensity in three closely related taxa, Elytrigia repens, E. intermedia and their hybrid was studied. Plants were exposed to three intensities of flooding for a 30‐day period. Response to flooding intensity was estimated by measuring dry mass of the following: total biomass, above‐ground living biomass, above‐ground dead biomass, below‐ground biomass, rhizome and root mass and by the allocation of dry mass into rhizomes and root:shoot ratio. Reduction of nearly all the biomass compartments with increasing flooding intensity was observed in the three taxa. All three taxa can thus be regarded as flood‐intolerant. Based on the parameters measured, E. repens is regarded as the relatively most flooding‐tolerant, E. intermedia as the least tolerant, while the hybrid displayed intermediate flooding tolerance. The higher flooding tolerance in E. repens was likely related to its ability to accumulate a sufficient mass of rhizomes before flooding, due to higher regeneration ability. E. repens also displayed the highest phenotypic plasticity, as deduced from the reaction norms constructed for total biomass and rhizome mass of particular clones of the three taxa studied. This indicates that, on the species level, E. repens is better adapted to changing environmental conditions and it can be expected to colonize flooded soils. Both Elytrigia species also occur as weeds: E. intermedia grows in agricultural environments in warm regions, while E. repens infests many different types of habitats. Where they co‐occur, hybridization between them may lead to the enrichment of their gene pools with genes responsible for survival of the parental species under extreme conditions; their weedy potential may thus be enhanced.
Skin manifestations with Rotavirus infections
Authors: Di Lernia Vito , Ricci Cinzia 
Published: January 2006

AbstractRotavirus infection is one the most frequent cause of diarrhea among infants and children. Although it is not associated to specific dermatologic clinical pictures, recently, different clinical manifestations have been reported in association with this infection. They include exanthema, Gianotti–Crosti syndrome, and Acute Infantile Hemorrhagic Edema. The condition can be diagnosed microbiologically with stool cultures. The prognosis is excellent in healthy, immunocompetent individuals.
Melanoma in a long‐standing lesion of chromoblastomycosis
Authors: Gon Airton dos Santos , Minelli Lorivaldo 
Published: January 2006

AbstractBackground  Chromoblastomycosis is a chronic cutaneous fungal infection where the presence of fibrous scars and continuous inflammation might be the propitious condition for the development of malignant neoplasms.Methods  We report a case of cutaneous melanoma arising on a leg of a man that had been affected by extensive chromoblastomycosis for more than 30 years.Results  A 70‐year‐old white man presented with an irregularly pigmented lesion over an area of fibrosis and verrucous lesions, previously diagnosed as chromoblastomycosis, on his left ankle. Histological examination showed an acral lentiginous melanoma, Clark level IV, thickness of 2.3 mm. Follow‐up for 7 years showed no signs of recurrence or metastasis.Conclusions  The association between malignancy and chromoblastomycosis is very uncommon, but medical staff who deal with this disease should be attentive to this possibility, as early detection of these neoplasms will provide an adequate treatment, improving survival and quality of life for those patients.
Superficial thrombophlebitic tuberculide
Authors: Motswaledi Hendrick M. , Schulz E. Joy 
Published: January 2006

AbstractBackground  Tuberculides are the result of immunologic reactions to hematogenously spread antigenic components of Mycobacterium tuberculosis. There are three recognized tuberculides – papulonecrotic tuberculide, erythema induratum of Bazin, and lichen scrofulosorum. In 1997, in Japan, Hara and coworkers reported five patients with what they called “nodular granulomatous phlebitis,” which they proposed was a fourth type of tuberculide. We describe a patient who presented with features identical to those reported by Hara et al. in order to draw attention to the previous report and to support the concept of a fourth tuberculide which clinically resembles superficial thrombophlebitis.Methods  A black South African man presented with cord‐like thickening of superficial veins on the antero‐medial aspects of the lower legs. Nodular swellings were palpable along the course of these veins. There was no evidence of tuberculosis elsewhere in the body, but the patient had a strongly positive tuberculin reaction. Skin biopsies were performed for histologic examination, culture, and polymerase chain reaction (PCR).Results  Histologic examination showed a granulomatous infiltrate localized to the veins in the subcutaneous fat. Stains for acid‐fast bacilli and culture were negative, but PCR was positive for M. tuberculosis DNA. The lesions responded promptly to antituberculous therapy.Conclusions  Our patient showed features identical to those of cases described by Hara and coworkers and assigned as a fourth type of tuberculide. As the lesions clinically resemble superficial thrombophlebitis, we propose the term “superficial thrombophlebitic tuberculide” rather than “nodular granulomatous phlebitis.”
Alopecia areata associated with regression of cutaneous melanoma
Authors: Yousefi Marjan , Payne Joseph R. , Barnhill Raymond L. 
Published: January 2006

A 41‐year‐old white female with a past medical history of hypothyroidism and alopecia universalis presented on January 24, 2002 with a recently changing mole. She indicated changes in size and color of the superior aspect of a mole that had been present for more than 8 years. She had approximately 20 lifetime peeling sunburns due to being a lifeguard. No family or previous personal history of skin cancers, including melanoma or atypical nevi, was reported. Her history of alopecia universalis began 12 years previously and has partially resolved with remaining patchy alopecia of the scalp and eyebrows. On diagnosis of alopecia universalis, she was initially treated with oral prednisone for 1 year and topical minoxidil for 3 months. Currently, she is not being treated for this condition. She denied other previous skin conditions. She had a surgical history of tonsillectomy at the age of 7 years. Her current medication includes levothyroxine (0.015 µg) for hypothyroidism diagnosed 12 years previously. She reported no known drug allergies.During the initial physical examination, she presented with phototype II skin with two adjacent pigmented lesions on her left foot within a 1.3 cm square. The first lesion on the left posterior distal heel was an irregular, brown–black, 0.5 × 0.6 cm macule. The second lesion, on the left posterior proximal heel, was an irregular, brown, speckled, 0.3 × 0.4 cm macule (Fig. 1). The patient had ophiasis of the scalp and total alopecia of the bilateral eyebrows. In keeping with the patient's wishes, alopecia lesions were not biopsied and clinical photographs of the alopecia are not included in this article.Malignant melanoma of the left footimageTwo 3 mm punch biopsies were performed within each lesion. The left posterior proximal lesion showed malignant melanoma, with a Breslow depth of 0.4 mm, anatomic level II, marked lymphocytic response and partial regression (Fig. 2). The left posterior distal lesion showed malignant melanoma in situ, arising in a lentiginous compound nevus, with architectural disorder and cytological atypia. These two lesions were concluded to be one lesion with clinical regression.Invasive malignant melanoma (× 100)imageShe underwent local excision with 1‐cm margins and sentinel lymph node biopsy owing to the presence of regression, which showed no evidence of metastatic melanoma. Lactate dehydrogenase and chest X‐ray were within normal limits. The alopecia areas were not biopsied previously or at that time.
Habitat loss and the structure of plant–animal mutualistic networks
Authors: Fortuna Miguel A. , Bascompte Jordi 
Published: January 2006

AbstractRecent papers have described the structure of plant–animal mutualistic networks. However, no study has yet explored the dynamical implications of network structure for the persistence of such mutualistic communities. Here, we develop a patch‐model of a whole plant–animal community and explore its persistence. To assess the role of network structure, we build three versions of the model. In the first version, we use the exact network of interactions of two real mutualistic communities. In the other versions, we randomize the observed network of interactions using two different null models. We show that the community response to habitat loss is affected by network structure. Real communities start to decay sooner than random communities, but persist for higher destruction levels. There is a destruction threshold at which the community collapses. Our model is the first attempt to describe the dynamics of whole mutualistic metacommunities interacting in realistic ways.
Factors predisposing to the development of anastomotic strictures in a single‐surgeon series of radical retropubic prostatectomies
Authors: HUANG GEORGE , LEPOR HERBERT 
Published: January 2006

OBJECTIVETo determine the rate of anastomotic stricture (AS) after radical retropubic prostatectomy (RRP) performed by one experienced surgeon, and to identify factors predisposing to its formation.PATIENTS AND METHODSIn all, 708 men were prospectively monitored for the development of AS after RRP. Potential risk factors for AS were analysed.RESULTSThere were no significant differences in age, Gleason score, nerve‐sparing status, intraoperative blood loss, degree of extravasation on initial cystography, or duration of the indwelling urinary catheter between men who developed AS and men who did not. The mean postoperative blood loss was significantly higher in men who developed AS. The incidence of AS was also significantly higher in men whose bladder necks were reconstructed more narrowly.CONCLUSIONThe amount of bleeding and the calibre of the reconstructed bladder neck were significantly associated with AS formation after RRP. The development of a haematoma from bleeding might explain the increased likelihood of AS. The mechanism of AS formation is unrelated to the degree of urinary extravasation on cystography, providing that a urinary catheter is left indwelling until extravasation resolves.
α1‐Adrenoceptor subtypes in isolated corporal tissue from patients undergoing gender re‐assignment
Authors: EL‐GAMAL OSAMA M. , SANDHU DAVINDER P.S. , TERRY TIM , ELLIOTT RUTH A. 
Published: January 2006

OBJECTIVETo investigate the pharmacology and functionality of α1‐adrenoceptors in human corpus cavernosum, and to determine the predominant subtype.MATERIALS AND METHODSCavernosal tissue specimens were obtained from the penises of 22 men (mean age 37.4 years) removed during gender re‐assignment surgery. The men had been maintained on long‐term oestrogen therapy before surgery, to aid the development of secondary feminine characteristics (oestrogen treatments were stopped 6 weeks before surgery). Corpus cavernosum strips were mounted in organ baths perfused with Krebs’ solution. A control concentration‐response curve (CRC) to phenylephrine (a nonselective α1‐agonist) was obtained. Then the tissues were incubated with the α1A antagonist, WB4101; the α1B antagonist, chloroethylclonidine; or the α1D antagonist BMY 7378 (all at 1 µm) and the CRC to phenylephrine was repeated. The concentration producing a half‐maximal response (EC50) and pKB values (logarithm of the dissociation constant, a measure of affinity) were determined.RESULTSWB4101 produced a parallel rightward shift of the CRC to phenylephrine, with a pKB of 7.49. BMY 7378 also produced a parallel rightward shift of the CRC to phenylephrine with a pKB of 6.45. Chloroethylclonidine had a similar effect on the phenylephrine CRC, with a pKB of 5.90.CONCLUSIONα1‐adrenoceptors in human cavernosal tissue have a relatively low affinity for BMY 7378 and chloroethylclonidine, but are more sensitive to WB4101. This confirms that the predominant α1‐adrenoceptor subtype in human corpus cavernosum is the α1A subtype and this might help in developing more selective antagonists and agonists for managing erectile dysfunction and priapism.
Reading in able and disabled readers from around the world: same or different? An illustration from a study of reading‐related processes in a Swahili sample of siblings
Authors: Grigorenko Elena L. , Ngorosho Damaris , Jukes Matthew , Bundy Donald 
Published: January 2006

Erratum. Journal of Research in Reading 29:2, 252 In this article, we discuss two characteristics of the majority of current behaviour‐ and molecular‐genetic studies of reading ability and disability, specifically, the ascertainment strategies and the populations from which samples are selected. In the context of this discussion, we present data that we collected on a sample of Swahili‐speaking siblings from Tanzania. With this sample, we (1) explore the efficiency and practicality of the single proband sibpair design and (2) provide data on the predictability of reading and spelling performance using reading‐related componential measures in a novel Swahili‐speaking sample. Specifically, we present the selection criteria, discuss the pattern of behavioural and behaviour‐genetic results obtained on the sample and compare these results with those available in the literature. We report behavioural and behaviour‐genetic correlations in this sample that are comparable with other studied samples in other languages, and discuss the similarities and differences. Thus, we demonstrate the suitability and effectiveness of the single sib ascertainment method for genetic analyses of reading ability and disability in novel samples in previously unstudied languages.
Molecular characterization and expression of four cDNAs encoding sucrose synthase from green bamboo Bambusa oldhamii
Authors: Chiu Wen‐Bin , Lin Chiou‐Hong , Chang Chun‐Ju , Hsieh Meng‐Hsun , Wang Ai‐Yu 
Published: January 2006

Summary

Bamboo is distinguished by its rapid growth. To investigate sucrose metabolism in this plant, we cloned the cDNAs encoding sucrose synthase (SuS) from Bambusa oldhamii and investigated their expression in growing shoots and leaves.
Four cDNA clones, BoSus1, BoSus2, BoSus3 and BoSus4, were isolated by screening a cDNA library from etiolated bamboo shoots. Recombinant BoSuS proteins were produced in Escherichia coli and purified by immobilized metal affinity chromatography and ultrafiltration. Semi‐quantitative reverse transcriptase–polymerase chain reaction (RT‐PCR) was used to determine the abundance of the transcript of each gene.
BoSus1 and BoSus3 may be duplicate or homeologous genes, the sequences of which show high identity. Similarly, BoSus2 shows high identity with BoSus4. Kinetic analysis showed that the two BoSuS isoforms of each type had similar michaelis constant (Km) values for sucrose, but different values for UDP. The four genes were expressed in various bamboo organs but were differentially regulated. The increase in the abundance of their mRNA paralleled the growth rate of the bamboo.
The results suggest that, in bamboo, SuS is encoded by at least four genes, each with a specific role in providing substrates for the polysaccharide biosynthesis and/or energy production necessary to support the rapid growth of this species.
Consumer preference among fluid milks: low‐fat vs. high‐fat milk consumption in the United States
Authors: Robb Cliff A. , Reynolds Laura M. , Abdel‐Ghany Mohamed 
Published: January 2006

AbstractThe present study uses data from the Continuing Survey of Food Intakes by Individuals 1994–1996, 1998 in order to analyse milk consumption by type, specifically high‐fat milk vs. low‐fat milk. Whereas trend analysis displays an overall increase in low‐fat milk consumption over the last few decades in the United States, a number of individuals still consume high‐fat milk varieties, and overall dietary intakes have yet to achieve recommended levels. In light of recent research regarding fat intakes, it is important to understand what factors might cause consumers to purchase high‐fat options given the number of low‐fat options available in the market. Through the use of Logistic regression, key socio‐economic and demographic variables are analysed in order to determine their impacts on the probability of consuming low‐fat milk vs. high‐fat milk. The results indicate that a number of factors do influence probability of low‐fat milk consumption as compared with high‐fat milk consumption. Most notably, probability of low‐fat milk consumption appears to be positively related to age, education level, and income level. African Americans and other minorities had a lower probability of consuming low‐fat milk when compared with White people in the sample population. Also, those respondents designated as low income or living in the South were less likely to consume low‐fat milk.
Cleavage of the membrane‐bound transcription factor OASIS in response to endoplasmic reticulum stress
Authors: Murakami Tomohiko , Kondo Shinichi , Ogata Maiko , Kanemoto Soshi , Saito Atsushi , Wanaka Akio , Imaizumi Kazunori 
Published: January 2006

AbstractWhen unfolded or misfolded proteins accumulate in the endoplasmic reticulum (ER), unfolded protein response (UPR) signals are transmitted from the ER to the nucleus and cytoplasm to facilitate protein folding. OASIS (old astrocyte specifically induced substance) is an ER stress transducer in astrocytes, a membrane‐bound transcription factor that activates genes in the ER stress response. When unfolded proteins accumulate in the ER, OASIS is cleaved at the membrane to release its cytoplasmic domain, which then enters the nucleus and activates target genes. Here, we showed that OASIS is processed by Site‐1 and ‐2 proteases (S1P and S2P), enzymes that reside at the Golgi apparatus and process activating transcription factor 6 (ATF6), in response to ER stress. We also showed that the cleavage of OASIS is triggered by its translocation to the Golgi apparatus. All deletion mutants for luminal domain of OASIS showed that proteolytic processing and translocation to the Golgi apparatus remained intact, indicating that OASIS does not have significant sequences for Golgi localization signals, different from the case of ATF6, and that there could be other systems for translocation of OASIS to the Golgi apparatus in response to ER stress.