bluuebunny/crossref_metadata_2025_split huggingface dataset:
Localization of the Vegetative Cell Wall Hydrolases LytC, LytE, and LytF on the
Bacillus subtilis
Cell Surface and Stability of These Enzymes to Cell Wall-Bound or Extracellular Proteases
Authors: Yamamoto Hiroki , Kurosawa Shin-ichirou , Sekiguchi Junichi 
Published: November 2003

ABSTRACT

LytF, LytE, and LytC are vegetative cell wall hydrolases in
Bacillus subtilis
. Immunofluorescence microscopy showed that an epitope-tagged LytF fusion protein (LytF-3xFLAG) in the wild-type background strain was localized at cell separation sites and one of the cell poles of rod-shaped cells during vegetative growth. However, in a mutant lacking both the cell surface protease WprA and the extracellular protease Epr, the fusion protein was observed at both cell poles in addition to cell separation sites. This suggests that LytF is potentially localized at cell separation sites and both cell poles during vegetative growth and that WprA and Epr are involved in LytF degradation. The localization pattern of LytE-3xFLAG was very similar to that of LytF-3xFLAG during vegetative growth. However, especially in the early vegetative growth phase, there was a remarkable difference between the shape of cells expressing LytE-3xFLAG and the shape of cells expressing LytF-3xFLAG. In the case of LytF-3xFLAG, it seemed that the signals in normal rod-shaped cells were stronger than those in long-chain cells. In contrast, the reverse was found in the case of LytE-3xFLAG. This difference may reflect the dependence on different sigma factors for gene expression. The results support and extend the previous finding that LytF and LytE are cell-separating enzymes. On the other hand, we observed that cells producing LytC-3xFLAG are uniformly coated with the fusion protein after the middle of the exponential growth phase, which supports the suggestion that LytC is a major autolysin that is not associated with cell separation.
Synthesis and Deformylation of
Staphylococcus aureus
δ-Toxin Are Linked to Tricarboxylic Acid Cycle Activity
Authors: Somerville Greg A. , Cockayne Alan , Dürr Manuela , Peschel Andreas , Otto Michael , Musser James M. 
Published: November 2003

ABSTRACT

In bacteria, translation initiates with formyl-methionine; however, the N-terminal formyl group is usually removed by peptide deformylase, an enzymatic activity requiring iron.
Staphylococcus aureus
δ-toxin is a 26-amino-acid polypeptide secreted predominantly with a formylated N-terminal methionine, which led us to investigate regulation of δ-toxin deformylation. We observed that during exponential and early postexponential growth, δ-toxin accumulated in the culture medium in formylated and deformylated forms. In contrast, only formylated δ-toxin accumulated after the early postexponential phase. The transition from producing both species of δ-toxin to producing only formyl-methionine-containing δ-toxin coincided with increased tricarboxylic acid (TCA) cycle activity. The TCA cycle contains several iron-requiring enzymes, which led us to hypothesize that TCA cycle induction depletes the iron in the culture medium, thereby inhibiting peptide deformylase activity. As expected,
S. aureus
depletes the iron in the culture medium between the postexponential and stationary phases of growth. Inhibition of δ-toxin deformylation was relieved by TCA cycle inactivation or by addition of supplemental iron to the culture medium. Of interest, peptides containing formyl-methionine are potent chemoattractants for neutrophils, suggesting that δ-toxin deformylation may have functional consequences. We found neutrophil chemotactic activity only with formylated δ-toxin. The
S. aureus
TCA cycle is derepressed upon depletion of rapidly catabolizable carbon sources; this coincides with the transition to producing only formylated δ-toxin and results in an increased inflammatory response. The proinflammatory response should increase host cell damage and result in the release of nutrients. Taken together, these results establish that there is an important linkage between bacterial metabolism and pathogenesis.
Structural and Topographical Studies of the Type IV Bundle-Forming Pilus Assembly Complex of Enteropathogenic
Escherichia coli
Authors: Hwang Jaiweon , Bieber David , Ramer Sandra W. , Wu Cheng-Yen , Schoolnik Gary K. 
Published: November 2003

ABSTRACT

The type IV bundle-forming pili (BFP) of enteropathogenic
Escherichia coli
(EPEC) are required for virulence in orally challenged human volunteers and for the localized adherence and autoaggregation in vitro phenotypes. BFP filament biogenesis and function are encoded by the 14-gene
bfp
operon. The BFP assembly complex, containing a BfpB-His
6
fusion protein, was chemically cross-linked in situ, and the complex was then purified from BFP-expressing EPEC by a combination of nickel- and BfpB antibody-based affinity chromatography. Characterization of the isolated complex by immunoblotting using BFP protein-specific antibodies showed that at least 10 of the 14 proteins specified by the
bfp
operon physically interact to form an oligomeric complex. Proteins localized to the outer membrane, inner membrane, and periplasm are within this complex, thus demonstrating that the complex spans the periplasmic space. A combination of immunofluorescence and immuno-gold thin-section transmission electron microscopy studies localized this complex to one pole of the cell.
THE POETICS OF PERSUASION: ABŪ TAMMĀM'S PANEGYRIC TO IBN ABĪ DU ĀD
Authors: Farrin Raymond 
Published: November 2003

AbstractIn this article I explore the way in which an alienated and rebuffed poet might improve strained relations with his patron by means of a qasīda offering, and so obtain recompense. Taking for analysis Abū Tammām's panegyric to the judge Ibn Abī Du ād, I show how the poet tailors the tripartite pre-Islamic form to suit his individual needs. In this poem, we find Abū Tammām using the nasīb to express sorrow for the loss of the patron and to offer an indirect apology, then describing through the rahīl the privation he endured as an exile. He lauds the judge in the madīh to dispose him in his favor, but the praise gets gradually fainter as the poet becomes more assertive. He devotes most of his attention here to arguing his case, by citing precedents for magnanimity and pardon and by attributing the estrangement between them to the malice of enviers. He concludes the section by boasting of his poetic prowess, and insinuates that decorative praise could turn to withering satire if the patron does not reward him. Monetary considerations thus preponderate at the end of the qasīda , despite protestations of affection elsewhere. By illuminating Abū Tammām's subtle methods for persuading the judge, the essay increases our awareness of the poet's rhetorical skill. Furthermore, it calls attention to a latent possibility in the panegyric genre. The praise poem could well be put to uses besides celebration. The case of Abū Tammām and Ibn Abī Du ād demonstrates that a supplicant poet, before giving up on the patron and becoming hostile himself, might still exploit the form to salve old wounds and earn a prize.
The emergence and characterization of macrophage-tropic SIV/HIV chimeric viruses (SHIVs) present in CD4+ T cell-depleted rhesus monkeys
Authors: Igarashi Tatsuhiko , Imamichi Hiromi , Brown Charles R , Hirsch Vanessa M , Martin Malcolm A 
Published: November 2003

AbstractHighly pathogenic simian immunodeficiency virus/human immunodeficiency virus type 1 chimeric viruses (SHIVs) induce an extremely rapid, systemic, and irreversible depletion of CD4+ T lymphocytes following their inoculation into rhesus macaques. Confocal fluorescence microscopy was used to demonstrate that high levels of viremia in infected animals were sustained by virus-producing tissue macrophage (mφ) following the irreversible elimination of CD4+ T lymphocytes by highly pathogenic SHIVDH12R. The envelope glycoproteins carried by plasma virus in CD4-depleted animals were found to contain specific alterations affecting the V2 region of gp120; similar V2 changes were observed during independent monkey infections. The altered V2 loops contained double amino acid deletions and the loss of a highly conserved N-linked glycosylation site. In contrast to the starting highly pathogenic SHIV, which is exclusively T cell-tropic, some mφ-phase SHIVs, bearing altered V2 regions, were able to establish spreading infections of cultured alveolar mφ.
Mononuclear phagocyte immunity and the neuropathogenesis of HIV-1 infection
Authors: Persidsky Yuri , Gendelman Howard E 
Published: November 2003

AbstractHuman immunodeficiency virus type 1 (HIV-1)-associated dementia is a neuroinflammatory brain disorder that is fueled by viral infection and immune activation of brain mononuclear phagocytes (MP; macrophages and microglia). MP serve as a reservoir for persistent viral infection, a vehicle for viral dissemination throughout the brain, and a major source of neurotoxic products that when produced in abundance, affect neuronal function. Such neurotoxic substances secreted by MP lead to clinical neurological impairment (cognitive, behavior, and motor abnormalities), which occurs usually years after the initial viral infection. How HIV-1 evades the immune function characteristic for MP as a first line of defense, including phagocytosis and intracellular killing, is not well understood despite more than two decades of study. In this report, we review the complex role(s) played by MP in the neuropathogenesis of HIV-1 infection. The clinical manifestations, pathology and pathogenesis, and treatment options are discussed in relationship to innate and adaptive immunity. Particular emphasis is given to the diversity of MP functions and how it may affect the disease process and manifestations. New insights into disease mechanisms are provided by advances in enhanced magnetic resonance imaging and proteomics to identify cell movement and genetic profiles of disease. New therapeutic strategies are discussed based on current knowledge of HIV-1-associated dementia pathogenesis.
Psychological disturbance associated with sexual abuse in people with learning disabilities
Authors: Sequeira Heather , Howlin Patricia , Hollins Shiela 
Published: November 2003

BackgroundThe association between sexual abuse, mental health and behavioural problems in people with learning disabilities has not previously been examined in a controlled study.AimsTo identify symptoms of psychological disturbance in adults with and without a confirmed history of sexual abuse.MethodThe study used a matched (1:1) case–control design comparing 54 adults who had experienced sexual abuse with 54 adults with no reported history of abuse. The two groups were selected from a community population of adults with learning disabilities living in residential care, and compared for selected psychiatric diagnoses and for scores on measures of disturbed behaviour.ResultsSexual abuse was associated with increased rates of mental illness and behavioural problems, and with symptoms of post-traumatic stress. Psychological reactions to abuse were similar to those observed in the general population, but with the addition of stereotypical behaviour. The more serious the abuse, the more severe the symptoms that were reported.ConclusionsThe study provides the first evidence from a controlled study that sexual abuse is associated with a higher incidence of psychiatric and behavioural disorder in people with learning disabilities.
Distal Radius Fractures and Concomitant Injuries: Experimental Studies Concerning Pathomechanisms
Authors: PECHLANER S. , KATHREIN A. , GABL M. , LUTZ M. , ANGERMANN P. , ZIMMERMANN R. , PEER R. , PEER S. , RIEGER M. , FREUND M. , RUDISCH A. 
Published: November 2003

Since Colles’ description of the distal radius fracture (1814) and the publication by Dupuytren (1834), the frequency of this fracture, and the problems associated with it, have been increasingly recognized. Not only the treatment but also the mechanism of injury of the different types of fracture have been analysed repeatedly. The various theories concerning the pathomechanism have led to names such as “sprain fracture”, “bent fracture”, “thrust fracture”, “compression fracture”, “snap fracture” and others. In our experimental studies, we attempted to simulate the pathomechanics of distal radius fractures, and to represent it illustratively. With the aid of a materials testing machine, 63 prepared cadaver parts were hyperextended at the wrist joint until distal radial fracture occurred. Accompanying injuries were identified radiologically and by dissection. Furthermore, the cadaver parts were deep-frozen and examined by means of computer tomography and cryo-section, using Kathrein’s method. Through experimental hyperextension, it was possible to generate dorsal, central and palmar types of fracture. We produced 42 dorsal, 14 central and seven palmar fractures. The extent to which the carpal bones of the proximal row were pressed against the dorsal or palmar edge; or the centre of the distal radial articular surface, was fundamental. Subsequent dissection showed multiple concomitant injuries in 40 cases (63%), and none in 23 cases (37%). One reason for the occurrence of such concomitant injuries may be the relative strengths of the bone and ligaments. Most frequently (27 cases, or 43%), we found a destabilization of the triangular fibrocartilage, with or without a bony avulsion fragment (fracture of the ulnar styloid process), followed by ruptures of the interosseous ligaments between the scaphoid and the lunate (20 cases, or 32%) and between the lunate and triquetrum (11 cases, or 18%). The application of knowledge gained from experimental studies carried out on fixed cadaver parts to clinical cases is problematic. This holds true for both concomitant injuries and fracture types. The lack of physiological defence reflexes as well as the deliberately slowed experimental procedure must be taken into account. On the other hand, in this series of experiments it was possible to generate experimentally many of the radius fractures found in clinical practice, together with their concomitant injuries.
Antibody responses to Porphyromonas gingivalis infection in a murine abscess model – involvement of gingipains and responses to re‐infection
Authors: Yoneda Masahiro , Hirofuji Takao , Motooka Noriko , Anan Hisashi , Hamachi Takafumi , Miura Mayumi , Ishihara Yoshihisa , Maeda Katsumasa 
Published: November 2003

Background:  Porphyromonas gingivalis is one of the most important periodontopathogens. It produces cysteine proteinases named gingipains. We previously examined the effect of gingipains on abscess formation in a murine model. The rgpA rgpB double and kgp mutants induced smaller abscesses than the wild type. Moreover, the rgpA rgpB kgp triple (gingipain‐null) mutant hardly showed lesion formation at all under the experimental conditions used, indicating that genes encoding gingipains are important for P. gingivalis virulence.Objectives:  Here, we further report the humoral immune responses induced by P. gingivalis strains.Methods:  After the lesions were apparently cured, sera were collected from the mice and immunoglobulin G (IgG) responses against the whole cell antigens of wild‐type P. gingivalis were measured.Results:  Wild‐type strain was found to induce a strong antibody reaction. On the other hand, the rgpA rgpB kgp triple and kgp mutants induced significantly lower antibody responses compared to the wild type. Western blotting analysis confirmed the differences in antibody production. Next, these mice were re‐infected with wild‐type strain. Mice that were first infected with wild‐type strain showed significantly smaller lesion formation than control mice that were first infected with medium only. On the other hand, mice that were first infected with mutant strains devoid of gingipain activities did not show resistance to re‐infection and immunoglobulins directed against gingipains may be protective.Conclusions:  These results suggest that gingipains play an important role in abscess formation in mice, and humoral immune responses seem to be partly responsible for the resistance to re‐infection by P. gingivalis.
Proteases augment the effects of lipopolysaccharide in rat gingiva
Authors: Ekuni D. , Yamamoto T. , Yamanaka R. , Tachibana K. , Watanabe T. 
Published: November 2003

Objectives:  Lipopolysaccharide (LPS) and proteases have been implicated as important factors in the initiation and progression of human periodontal diseases. A single application of LPS or proteases is insufficient to induce periodontal pocket formation or periodontitis. The aim of the present study was to assess the combined effect of lipopolysaccharide and proteases on rat periodontal tissues, and create a periodontal disease model.Materials and methods:  Forty male Wistar rats were divided into four groups: combination group (treated with both LPS and proteases solutions); LPS group; proteases group; and control. Each solution was introduced daily into the palatal gingival sulcus of maxillary molars for 8 weeks. The tissues were evaluated histometrically and immunohistochemically.Results:  In the LPS group, elongation of rete ridge, apical migration of junctional epithelium (JE), increased numbers of B cells in connective tissue, and resorption of alveolar bone were observed. In the proteases group, the increase in the number of infiltrating polymorphonuclear leukocytes and blood vessels in the connective tissue was greater than that of the LPS group.Conclusions:  The effects of LPS on periodontal tissues differed from those of proteases. The addition of proteases augmented and increased the effects of LPS, which were apical migration, intraepithelial cleavage of JE, and increased B cell density. The lesions in the combination group resembled established lesions of human periodontitis, with the exception of the low density of plasma cells.
Effects of growth/differentiation factor‐5 on human periodontal ligament cells
Authors: Nakamura Toshiaki , Yamamoto Matsuo , Tamura Masato , Izumi Yuichi 
Published: November 2003

Objectives:  Growth/differentiation factor‐5 (GDF‐5), a member of the transforming growth factor‐β superfamily, shows a close structural relationship to bone morphogenetic proteins and plays crucial roles in skeletal, tendon, and ligament morphogenesis. The mRNA encoding GDF‐5 is also expressed during odontogenesis, especially in dental follicle tissue. While this suggests that GDF‐5 participates in the formation of alveolar bone and the periodontal ligament, cementum, and dental root, the physiologic role of GDF‐5 in these tissues in adulthood remains unclear. We therefore investigated GDF‐5 effects upon cultures of human periodontal ligament (HPDL) cells.Material and methods:  HPDL cells were obtained from healthy periodontal ligaments of individuals. Tetrazolium reduction assay was carried out for cell proliferation assay. Alkaline phosphatase (ALP) activity was estimated by measuring light absorbance at 405 nm. Reverse transcription‐polymerase chain reaction (RT‐PCR) and northern analysis were performed for gene expression in cultured HPDL cells. Sulfated glycosaminoglycan (sGAG) synthesis was evaluated by histochemical staining and a quantitative dye‐binding method.Results:  Expression of GDF‐5 and its receptor was demonstrated in HPDL cells by RT‐PCR. ALP activity in HPDL cells was significantly decreased by addition of rhGDF‐5 at 10–1000 ng/ml (p < 0.05). Although northern analysis showed little change in gene expression for collagen α2(I) in rhGDF‐5‐stimulated HPDL cells, rhGDF‐5 dose‐dependently enhanced cell proliferation. This proliferative effect persisted for 16 d. Alcian blue staining and dye‐binding assays indicated that sGAG synthesis was enhanced by rhGDF‐5.Conclusion:  rhGDF‐5 may provide an environment fostering periodontal healing or regeneration by affecting extracellular matrix metabolism.
Serological Status and Abortion Rate in Progeny Obtained by Natural Service or Embryo Transfer fromNeospora caninum‐Seropositive Cows
Authors: Campero C. M. , Moore D. P. , Lagomarsino H. , Odeón A. C. , Castro M. , Visca H. 
Published: November 2003

SummaryBovine neosporosis is an important disease in dairy herds in Argentina. Embryo transfer (ET) technology offers the opportunity to minimize vertical transmission of neosporosis. The objective of this work was to compare the serological status and the incidence of abortion between heifers obtained via natural service and heifers obtained by ET fromNeospora‐infected cows. Progeny from eightNeospora‐infected cows belonging to a commercial dairy farm where ET was routinely performed were studied. Between 1996 and 2001, 16 and 15 heifers were obtained by natural service and ET, respectively. Serostatus and reproductive performance were recorded in both progeny. Serostatus was determined by indirect fluorescent antibody test (IFAT). All heifers obtained by natural service were seropositive and six of 16 pregnancies ended in abortion. All heifers obtained by ET were seronegative and only two abortions of 15 pregnancies were recorded.
Decay of Acquired Colostral Antibodies to Actinobacillus pleuropneumoniae in Pigs
Authors: Vigre H. , Ersbøll A. K. , Sørensen V. 
Published: November 2003

SummaryThe main objective of this study was to estimate the decay of acquired colostral antibodies to Actinobacillus pleuropneumoniae serotype 2 in pigs. Data were obtained from pigs in an isolated cohort of 47 pigs born to five sows seropositive to A. pleuropneumoniae serotype 2. The pigs were examined serologically at 18 different times from birth until an age of about 22 weeks, using an A. pleuropneumoniae serotype 2‐specific blocking enzyme‐linked immunosorbent assay. Antibody concentration was expressed as an OD% derived from the optical density of the sample and the median from eight wells without serum on the same plate. A non‐linear mixed model assuming a constant rate of decay (half‐life) was specified and fitted to the serological data. To estimate the between‐pig variability of different components, between‐pig random effects of each component of the model were estimated. The estimated average half‐life of acquired colostral antibodies was approximately 2 weeks, but there was a considerable variation between pigs (half‐life ranged from 1–3 weeks). The duration until acquired colostral antibodies were no longer detectable ranged from 2 weeks to 2 months postpartum among the pigs in the study, mainly depending on the initial level of acquired colostral antibodies to A. pleuropneumoniae serotype 2.
Prader–Willi syndrome: clinical picture, psychosocial support and current management
Authors: Wigren M. , Hansen S. 
Published: November 2003

AbstractAim  Prader–Willi syndrome (PWS) is a rare, genetically based disorder that occurs in about 1 of 15 000 live‐born children. To raise a child with PWS is challenging for parents and requires support from multiprofessional habilitation services. This paper maps the need for psychosocial support and current management of children and adolescents with PWS.Method  Parents to 58 children with PWS (aged 5–18 years) completed questionnaires covering clinical, diagnostic and psychosocial issues.Results  The children received their diagnosis at a mean age of 2.5 year. Growth hormone treatment was given to 72%. Sixty‐three per cent of the sample was not overweight. Neuropsychiatric symptoms were common from early age and some were related to obesity. Most parents wanted information as to availability of external resources and future child needs. Few parents needed family‐directed support.Conclusion  The overall impression is that the eating disorder is managed relatively well. Even so PWS symptoms typically exacerbate over time and consequently parents need continuous support throughout childhood and adolescence. Greater attention should be paid to idiosyncrasies in cognitive functioning and to clinical markers of neuropsychiatric problems.