bluuebunny/crossref_metadata_2025 huggingface dataset:
Width/length ratios of normal clinical crowns of the maxillary anterior dentition in man
Authors: Sterrett John D. , Oliver Trudy , Robinson Fonda , Fortson Weston , Knaak Ben , Russell Carl M.
Published: October 2003

Abstract. The purpose of this investigation was to analyze the clinical crown of the 3 tooth groups of the maxillary anterior sextant of the permanent dentition of normal subjects with respect to (i) width, length and the width/length ratios and (ii) determine if there is a correlation between tooth dimensions or tooth group ratios and subject height. Subjects (≥20 y.o.) were recruited for this study if (i) the free gingival margin on the facial surface of teeth in the maxillary sextant was positioned apical to the cervical bulge, (ii) there was no evidence of attachment loss; as determined by lack of a detectable CEJ and (iii) the marginal tissue was knife edged in form, firm in consistency and coral pink in color. Teeth were excluded if (i) there was evidence of gingival alteration, i.e., gingival overgrowth/hyperplasia, inflammation, altered passive eruption, attachment loss, gingival recession or history of periodontal surgery, or (ii) there was evidence or history of incisal edge/proximal tooth alteration as in, i.e., restorative intervention, traumatic injury or occlusal wear into dentin. At least 1 suitable tooth from each tooth group of the maxillary anterior dentition had to be present. A maxillary impression was taken and poured in yellow die stone. The widest mesial‐distal portion and the longest apical‐coronal portion of the test teeth were measured. Gender, ethnicity and subject height (SH) were recorded for each participant. Due to a limited ethnic diversity only data from the Caucasian group were analyzed. The mean coronal tooth width (mm) of males versus females was CI: 8.59 versus 8.06, LI: 6.59 versus 6.13 and CA: 7.64 versus 07.15. The mean coronal tooth length (mm) of males versus females was CI: 10.19 versus 9.39, LI: 8.70 versus 7.79 and CA: 10.06 versus 8.89. All width and length measures were significantly greater for males than for females. The mean coronal tooth width/length ratios for males versus females was CI: 0.85 versus 0.86, LI: 0.76 versus 0.79 and CA: 0.77 versus 0.81. A comparison between genders of the width/length ratios of the CI and LI were found not to differ, however the CA ratio for females was significantly greater than for males. A statistically significant difference was found to exist between the mean (cm) SH for males versus females: 181.2 versus 164.0. A positive correlation (p≤0.0001 to 0.0691) was found to exist between tooth group width/height ratios within genders. No significant correlation was found between any of the tooth dimensions or tooth group ratios and SH. The results of this study indicate that within male and female Caucasians, the mean width/length ratio of the maxillary 3 anterior tooth groups is 0.81. As well, within both genders there is a positive correlation between tooth group width/length ratios. The significance of these findings with respect to periodontal mucogingival plastic surgical procedures is discussed.
Non‐surgical periodontal treatment with and without adjunctive metronidazole in smokers and non‐smokers
Authors: Palmer R. M. , Matthews J. P. , Wilson R. F.
Published: October 2003

Abstract. Aim: To determine whether adjunctive metronidazole therapy would compensate for the poorer treatment response to scaling and root planing reported in smokers. Method: A single‐blind, randomised clinical trial of 28 smokers and 56 non‐smokers, stratified for periodontitis disease severity and randomly allocated to 3 treatment groups: (1) Scaling and root planing using an ultrasonic scaler with local anaesthesia (SRP), (2) SRP+metronidazole tabs 200 mg tds for 7 days, (3) SRP+2 subgingival applications of 25% metronidazole gel. Probing depths (PD) and attachment levels (AL) were recorded with a Florida probe at baseline, 2 months and 6 months post treatment by a single examiner who was unaware of the treatment modality. Results were analysed for all sites with baseline probing depths equal to or greater than Florida probe recordings of 4.6 mm using analysis of variance. Results: Reductions in probing depth at 6 months were significantly less (p<0.001) in the smokers (mean 1.23 mm, 95% confidence intervals=1.05 to 1.40 mm) than in the non‐smokers (1.92, 1.75 to 2.09 mm). Attachment level gains were approximately 0.55 mm and there was no statistically significant difference between smokers and non‐smokers. There were no differences in any clinical measure in response to the three treatment regimens at 2 or 6 months for either smokers or non‐smokers. A reduction in the proportion of spirochaetes was observed at 6 months which was less in smokers than in nonsmokers (p=0.034). Multiple linear regression analysis on probing depth at 6 months demonstrated that smoking was a significant explanatory factor (p<0.001) for poor treatment outcome, whilst the presence or absence of adjunctive metronidazole was not (p=0.620). Conclusion: This study confirms that smokers have a poorer treatment response to SRP, regardless of the application of either systemic or locally applied adjunctive metronidazole.
Oral treatment with SRP299 (killed Mycobacterium vaccae) inhibits experimental periodontal disease in Wistar rats
Authors: Breivik Torbjörn , Rook Graham A. W.
Published: October 2003

Le Mycobacterium vaccae injecté en sous‐cutané a prouvé son efficacitéà prévenir et traiter la maladie parodontale (PD) induite par ligatures chez le rat Wistar. Puisque les mycobactéries sont prélevées via les patchs de Peyers dans l'intestin, l'habilité du SRP299 (M. vaccae tué) à empêcher la PD par ligature chez le rat Wistar et à moduler les réponses de la corticostérone et de la cytokine qui les accompagnent a été testée. Une dose buccale simple de SRP299 (1 mg) a été administrée quatorze jours avant le placement des ligatures. PD a été enregistrée lorsque les ligatures sont restées en place pendant 56 jours. Le SRP299 buccal a réduit la perte osseuse (p=0.036, RX; p=0.061, histométrie) et la perte de fibre, tant dans les sites ligaturés (p=0.0047) que les contrôles (p=0.005), et aussi la teneur en TNF‐alpha (p=0.0137) et la corticostérone (p=0.048) induite par l'endotoxine intrapéritonéale (LPS). Le SRP299 administré par voie buccale diminue la perte de fibre et d'os induits par ligature dans le modèle présent. Cet effet peut être attribuéà l'habilité connue du SRP299 à susciter les cellules T de régulation bien que ce mécanisme ne pouvait pas être étudié dans cette étude. Les rats traités avait également moins d'HPA excitables. L'axe HPA lorsqu'il est hyperactivé est connu comme étant un facteur de risque dans la PD humaine. Des essais cliniques de SRP299 dans la PD humaine sont maintenant justifiés.
Clinical evaluation of the Er:YAG laser in combination with an enamel matrix protein derivative for the treatment of intrabony periodontal defects: a pilot study
Authors: Schwarz Frank , Sculean Anton , Georg Thomas , Becker Jürgen
Published: October 2003

Objectives: The aim of the present study was to compare the combination therapy of deep intrabony periodontal defects using an Er:YAG laser (ERL) and enamel matrix protein derivative (EMD) to scaling and root planing+ ethylenediaminetetraacetic acid (EDTA)+EMD.

Material and Methods: Twenty‐two patients with chronic periodontitis, each of whom displayed 1 intrabony defect, were randomly treated with access flap surgery and defect debridement with an Er:YAG (160 mJ/pulse, 10 Hz) plus EMD (test) or with access flap surgery followed by scaling and root planing (SRP) with hand instruments plus EDTA and EMD (control). The following clinical parameters were recorded at baseline and at 6 months: plaque index, gingival index, bleeding on probing (BOP), probing depth (PD), gingival recession, and clinical attachment level (CAL). No differences in any of the investigated parameters were observed at baseline between the two groups.

Results: Healing was uneventful in all patients. At 6 months after therapy, the sites treated with ERL and EMD showed a reduction in mean PD from 8.6±1.2 mm to 4.6±0.8 mm and a change in mean CAL from 10.7±1.3 mm to 7.5±1.4 mm (p<0.001). In the group treated with SRP+EDTA+EMD, the mean PD was reduced from 8.1±0.8 mm to 4.0±0.5 mm and the mean CAL changed from 10.4±1.1 mm to 7.1±1.2 mm (p<0.001). No statistically significant differences in any of the investigated parameters were observed between the test and control group.

Conclusion: Within the limits of the present study, it may be concluded that both therapies led to short‐term improvements of the investigated clinical parameters, and the combination of ERL and EMD does not seem to improve the clinical outcome of the therapy additionally compared to SRP+EDTA+EMD.
Effectiveness of interventions to promote continuing professional development for dentists
Authors: Best Helen A , Messer Louise Brearley
Published: October 2003

Background:  Continuing education is incumbent upon dentists as health professionals, but its promotion may be required, particularly in order to ensure regular professional updating. Continuing professional development may be delivered in a variety of ways, and new strategies and techniques must be evaluated for effectiveness.

Aim:  To evaluate the effectiveness of two interventions utilizing the philosophies and techniques of the discipline of Quality Improvement.

Method:  A self‐assessment instrument (a manual) for quality dental practice was developed using the Delphi technique. A randomized, controlled trial of the interventions was conducted under field conditions for dental practice in Victoria, Australia. Dentists in Test Groups 1 and 2 completed the self‐assessment manual, and received relevant references and their own scores for the manual in comparison with empirical standards. Dentists in Test Group 1 also attended a continuing education course on Quality Improvement. Dentists in Control Group 1 completed the manual only and received feedback of their scores. Dentists in Test Groups 1 and 2, and in Control Group 1 completed the manual again after 1 year as a post‐intervention follow‐up. Dentists in Control Group 2 completed the manual only at 1 year.

Results:  The intervention involving self‐assessment, receipt of scores and references for the manual resulted in modest improvements in total scores for dentists after 1 year, although a response bias was apparent.

Conclusion:  An effective method of facilitating change in quality dental practice was identified. Assessment of strategies and techniques for professional development of dentists should include observation of patterns of participation.
Allowed N-glycosylation sites on the Kv1.2 potassium channel S1–S2 linker: implications for linker secondary structure and the glycosylation effect on channel function
Authors: ZHU Jing , WATANABE Itaru , POHOLEK Amanda , KOSS Matthew , GOMEZ Barbara , YAN Chaowen , RECIO-PINTO Esperanza , THORNHILL William B.
Published: October 2003

N-glycosylation is a post-translational modification that plays a role in the trafficking and/or function of some membrane proteins. We have shown previously that N-glycosylation affected the function of some Kv1 voltage-gated potassium (K+) channels [Watanabe, Wang, Sutachan, Zhu, Recio-Pinto and Thornhill (2003) J. Physiol. (Cambridge, U.K.) 550, 51–66]. Kv1 channel S1–S2 linkers vary in length but their N-glycosylation sites are at similar relative positions from the S1 or S2 membrane domains. In the present study, by a scanning mutagenesis approach, we determined the allowed N-glycosylation sites on the Kv1.2 S1–S2 linker, which has 39 amino acids, by engineering N-glycosylation sites and assaying for glycosylation, using their sensitivity to glycosidases. The middle section of the linker (54% of linker) was glycosylated at every position, whereas both end sections (46% of linker) near the S1 or S2 membrane domains were not. These findings suggested that the middle section of the S1–S2 linker was accessible to the endoplasmic reticulum glycotransferase at every position and was in the extracellular aqueous phase, and presumably in a flexible conformation. We speculate that the S1–S2 linker is mostly a coiled-loop structure and that the strict relative position of native glycosylation sites on these linkers may be involved in the mechanism underlying the functional effects of glycosylation on some Kv1 K+ channels. The S3–S4 linker, with 16 amino acids and no N-glycosylation site, was not glycosylated when an N-glycosylation site was added. However, an extended linker, with an added N-linked site, was glycosylated, which suggested that the native linker was not glycosylated due to its short length. Thus other ion channels or membrane proteins may also have a high glycosylation potential on a linker but yet have similarly positioned native N-glycosylation sites among isoforms. This may imply that the native position of the N-glycosylation site may be important if the carbohydrate tree plays a role in the folding, stability, trafficking and/or function of the protein.
Characterization of a new p94-like calpain form in human lymphocytes
Authors: DE TULLIO Roberta , STIFANESE Roberto , SALAMINO Franca , PONTREMOLI Sandro , MELLONI Edon
Published: October 2003

Human circulating PBMC (peripheral blood mononuclear cells) contain three calpain isoforms distinguishable on the basis of their chromatographic properties. Two of these proteases belong to the ubiquitous calpain subfamily, corresponding to the classical μ- and m-calpain forms. The third, which shows peculiar activating and regulatory properties, is an alternatively spliced calpain 3 (p94) form. This new calpain differs from calpain 3 in that it has lost IS1 insertion and exon 15, a lysine-rich sequence regarded as a nuclear translocation signal. PBMC p94-calpain undergoes activation and inactivation without the accumulation of a low-Ca2+-requiring form that is typical of the classical activation processes of μ- and m-calpain. Furthermore, it differs from the ubiquitous forms in that it displays a lower sensitivity to calpastatin. On the basis of these selective properties, it can be postulated that PBMC p94-calpain can be activated in response to specific stimuli that are not effective on the other calpain isoenzymes. The enzyme is preferentially expressed in B- and T-lymphocytes, whereas it is poorly expressed in natural killer cells and almost undetectable in polymorphonuclear cells. This distribution might reflect the specific function of this protease, which is preferentially present in cells devoted to the production of the humoral, rather than to the cellular, immune response.
Regulation of oxidative phosphorylation in different muscles and various experimental conditions
Authors: KORZENIEWSKI Bernard
Published: October 2003

It has been shown previously that direct stimulation of oxidative-phosphorylation complexes in parallel with the stimulation of ATP usage is able to explain the stability of intermediate metabolite (ATP/ADP, phosphocreatine/creatine, NADH/NAD+, protonmotive force) concentrations accompanied by a large increase in oxygen consumption and ATP turnover during transition from rest to intensive exercise in skeletal muscle. It has been also postulated that intensification of parallel activation in the ATP supply–demand system is one of the mechanisms of training-induced adaptation of oxidative phosphorylation in skeletal muscle. In the present paper, it is demonstrated, using the computer model of oxidative phosphorylation in intact skeletal muscle developed previously, that the direct activation of oxidative phosphorylation during muscle contraction can account for the following kinetic properties of oxidative phosphorylation in skeletal muscle encountered in different experimental studies: (i) increase in the respiration rate per mg of mitochondrial protein at a given ADP concentration as a result of muscle training and decrease in this parameter in hypothyroidism; (ii) asymmetry (different half-transition time, t1/2) in phosphocreatine concentration time course between on-transient (rest→work transition) and off-transient (recovery after exercise); (iii) overshoot in phosphocreatine concentration during recovery after exercise; (iv) variability in the kinetic properties of oxidative phosphorylation in different kinds of muscle under different experimental conditions. No other postulated mechanism is able to explain all these phenomena at the same time and therefore the present paper strongly supports the idea of the parallel activation of ATP usage and different oxidative-phosphorylation complexes during muscle contraction.
Eukaryotic translation-initiation factor eIF2β binds to protein kinase CK2: effects on CK2α activity
Authors: LLORENS Franc , ROHER Nerea , MIRÓ Francesc A. , SARNO Stefania , RUIZ F. Xavier , MEGGIO Flavio , PLANA Maria , PINNA Lorenzo A. , ITARTE Emilio
Published: October 2003

eIF2 (eukaryotic translation-initiation factor 2) is a substrate and an interacting partner for CK2 (protein kinase CK2). Co-immuno-precipitation of CK2 with eIF2β has now been observed in HeLa cells, overexpressing haemagglutinin-tagged human recombinant eIF2β. A direct association between His6-tagged human recombinant forms of eIF2β subunit and both the catalytic (CK2α) and the regulatory (CK2β) subunits of CK2 has also been shown by using different techniques. Surface plasmon resonance analysis indicated a high affinity in the interaction between eIF2β and CK2α, whereas the affinity for the association with CK2β is much lower. Free CK2α is unable to phosphorylate eIF2β, whereas up to 1.2 mol of phosphate/mol of eIF2β was incorporated by the reconstituted CK2 holoenzyme. The N-terminal third part of eIF2β is dispensable for binding to either CK2α or CK2β, although it contains the phosphorylation sites for CK2. The remaining central/C-terminal part of eIF2β is not phosphorylated by CK2, but is sufficient for binding to both CK2 subunits. The presence of eIF2β inhibited CK2α activity on calmodulin and β-casein, but it had a minor effect on that of the reconstituted CK2 holoenzyme. The truncated forms corresponding to the N-terminal or central/C-terminal regions of eIF2β were much less inhibitory than the intact subunit. The results demonstrate that the ability to associate with CK2 subunits and to serve as a CK2 substrate are confined to different regions in eIF2β and that it may act as an inhibitor on CK2α.
Association between inflammatory mediators and the fibrinolysis system in infectious pleural effusions
Authors: ALEMÁN Carmen , ALEGRE José , MONASTERIO Jasone , SEGURA Rosa M. , ARMADANS Lluís , ANGLÉS Ana , VARELA Encarna , RUIZ Eva , DE SEVILLA Tomás FERNÁNDEZ
Published: October 2003

The response of the fibrinolytic system to inflammatory mediators in empyema and complicated parapneumonic pleural effusions is still uncertain. We prospectively analysed 100 patients with pleural effusion: 25 with empyema or complicated parapneumonic effusion, 22 with tuberculous effusion, 28 with malignant effusion and 25 with transudate effusion. Inflammatory mediators, tumour necrosis factor-α (TNF-α), interleukin-8 (IL-8) and polymorphonuclear elastase, were measured in serum and pleural fluid. Fibrinolytic system parameters, plasminogen, tissue-type plasminogen activator (t-PA) and urokinase PA, PA inhibitor type 1 (PAI 1) and PAI type 2 concentrations and PAI 1 activity, were quantified in plasma and pleural fluid. The Wilcoxon signed-rank test was used to compare plasma and pleural values and to compare pleural values according to the aetiology of the effusion. The Pearson correlation coefficient was used to assess the relationship between fibrinolytic and inflammatory markers in pleural fluid. Significant differences were found between pleural and plasma fibrinolytic system levels. Pleural fluid exudates had higher fibrinolytic levels than transudates. Among exudates, tuberculous, empyema and complicated parapneumonic effusions demonstrated higher pleural PAI levels than malignant effusions, whereas t-PA was lowest in empyema and complicated parapneumonic pleural effusions. PAI concentrations correlated with TNF-α, IL-8 and polymorphonuclear elastase when all exudative effusions were analysed, but the association was not maintained in empyema and complicated parapneumonic effusions. A negative association found between t-PA and both IL-8 and polymorphonuclear elastase in exudative effusions was strongest in empyema and complicated parapneumonic effusions. Blockage of fibrin clearance in empyema and complicated parapneumonic effusions was associated with both enhanced levels of PAIs and decreased levels of t-PA.
Circulating oxidized low-density lipoprotein is increased in hypertension
Authors: FROSTEGÅRD Johan , WU Ruihua , LEMNE Carola , THULIN Thomas , WITZTUM Joseph L. , DE FAIRE Ulf
Published: October 2003

Oxidized low-density lipoprotein (OxLDL) and autoantibodies to OxLDL (aOxLDL) are implicated in the development of atherosclerosis. The objective of this study was to determine the importance of these factors in hypertension, a major risk factor for atherosclerosis. Samples were obtained from 111 men with established hypertension (diastolic pressure >95 mmHg) from the Swedish component of an ongoing hypertension study (European Lacidipine study on Atherosclerosis, ELSA) and from 75 normotensive control men, who were from a Swedish population-screening programme (diastolic pressure <80 mmHg). The presence of carotid atherosclerosis and the intima-media thicknesses were determined by ultrasonography. A monoclonal antibody to OxLDL, EO6, was used to determine oxidation epitopes in LDL. aOxLDL of IgG and IgM subclass were tested by ELISA against OxLDL. Hypertensive men had increased OxLDL levels compared with normotensives (P=0.002), whereas autoantibodies tested were largely similar between groups. There was no association between the antibodies tested, or OxLDL and carotid atherosclerosis. Age was not associated with OxLDL or aOxLDL measurements. Taken together, our findings indicate that OxLDL is elevated in hypertensive men, which may predispose to atherosclerosis in hypertension. In contrast, aOxLDL levels were unchanged and the role of aOxLDL may depend on disease stage and/or type.
A rapid procedure to ascertain the antimicrobial efficacy of oral care formulations
Authors: Sreenivasan P. K. , Tambs G. , Gittins E. , Nabi N. , Gaffar A.
Published: October 2003

A rapid method examining the antimicrobial efficacy of oral care formulations with alamar blue, an oxidation‐reduction dye with fluorescent end‐points, is described. Significant correlations between increasing viable plate counts of the oral bacteria Actinomyces viscosus, Streptococcus sanguis, Streptococcus mutans and Actinobacillus actinomycetemcomitans and increased alamar fluorescence were noted. Metabolically active bacteria reduced alamar with the reduced dye found in the cell‐free filtrate. Insignificant alamar reductions were noted in the absence of bacteria or by spent culture supernatants. The efficacy of mouthrinses with clinically proven antiplaque agents such as chlorhexidine or cetylpyridinium chloride were determined by alamar blue. In a model system with A. viscosus, triclosan dentifrices demonstrate a dose‐dependent effect on bacteria. Human salivary bacteria demonstrate increasing alamar fluorescence with increasing plate counts. A clinical study examined the effects of rinsing with chlorhexidine or cetylpyridinium chloride mouthrinses in comparison with a placebo mouthrinse and water on salivary bacteria. Rinsing with chlorhexidine resulted in the least number of bacteria by alamar and plate count methods. In summary, the current study demonstrates the utility of alamar blue to examine the antimicrobial effects of oral care formulations in laboratory and clinical studies.
Sequence analysis of kgp in Porphyromonas gingivalis isolates from periodontitis patients
Authors: Beikler T. , Peters U. , Ehmke B. , Flemmig T. F.
Published: October 2003

The aim of the present study was to determine sequence variation in the Lys‐x‐specific protease (Kgp) encoding gene kgp of Porphyromonas gingivalis and to analyze its association with periodontal disease severity. Pooled subgingival plaque samples were obtained from the six most severely affected sites of 102 patients with periodontitis. Sequence analysis of the kgp gene in 23 clinical P. gingivalis isolates resulted in the identification of two distinct kgp types (kgp‐I and kgp‐II) according to sequence differences in the region encoding the catalytic domain. Restriction analysis revealed that 59 of the 102 patients were colonized by kgp‐I and 43 by kgp‐II. Patients harboring kgp‐I or kgp‐II showed no significant difference in the severity of periodontal disease as assessed by pocket probing depth and bleeding on probing following adjustment for smoking habit and age. Moreover, no differences in proteolytic activity of Kgp‐I and Kgp‐II were detected. The results indicated that two kgp types are maintained in natural populations of P. gingivalis.
Use of suppression subtractive hybridization to identify downy mildew genes expressed during infection of Arabidopsis thaliana
Authors: Bittner‐Eddy Peter D. , Allen Rebecca L. , Rehmany Anne P. , Birch Paul , Beynon Jim L.
Published: October 2003

Peronospora parasitica is an obligate biotrophic oomycete that causes downy mildew in Arabidopsis thaliana and Brassica species. Our goal is to identify P. parasitica (At) genes that are involved in pathogenicity. We used suppression subtractive hybridization (SSH) to generate cDNA libraries enriched for in planta‐expressed parasite genes and up‐regulated host genes. A total of 1345 clones were sequenced representing cDNA fragments from 25 putative P. parasitica (At) genes (Ppat 1–25) and 618 Arabidopsis genes. Analyses of expression patterns showed that 15 Ppats were expressed only in planta. Eleven Ppats encoded peptides with homology (BlastP values < 1e‐05) to proteins with roles in membrane or cell wall biosynthesis, amino acid metabolism, osmoregulation, cation transport, phosphorylation or protein secretion. The other 14 represent potentially novel oomycete genes with none having homologues in an extensive Phytophthora species EST database. A full‐length sequence was obtained for four Ppats and each encoded small cysteine‐rich proteins with amino‐terminal signal peptide sequences. These results demonstrate the utility of SSH in obtaining novel in planta‐expressed genes from P. parasitica (At) that complements other gene discovery approaches such as EST sequencing.
Pathogenic fungi: leading or led by ambient pH?
Authors: Prusky Dov , Yakoby Nir
Published: October 2003

Pathogenic fungi have successfully attacked a wide range of hosts, which has forced them into ambient‐adaptation. pH is one of the major ambient traits affecting the activity of pathogenicity factors secreted by the pathogen, hence, a pH sensing‐response system was developed to enable the pathogen to tailor its arsenal to best fit its host. The pacC palA, B, C, F, H and I apparatus was first identified in Aspergillus nidulans and later found in other fungi. Secreted pathogenicity factors, such as cell wall degrading enzymes, were recognized to be controlled by environmental pH and later shown to be regulated by the pH regulatory system, either directly or by harbouring the pacC consensus sequence. The ability of the pathogen to actively increase or decrease its surrounding pH allows it to select the specific virulence factor, out of its vast arsenal, to best fit a particular host.
Application of the frequency of dividing cells technique to estimate the in situ growth rate of Microcystis (Cyanobacteria)
Authors: Tsujimura Shigeo
Published: October 2003

1. Diel patterns of the frequency of dividing cells (FDC) of the bloom‐forming cyanobacteria Microcystis were investigated using both culture strains and natural populations.

2. In laboratory experiments, diel division cycles were examined twice in a 24‐h light/dark cycle during time‐course batch incubations of six culture conditions using two strains (morphospecies) of Microcystis (M. aeruginosa and M. wesenbergii). While both strains clearly showed phased cell division in the light period during the logarithmic growth phase, the peaks of FDC became unclear towards the stationary phases. Some dividing cells were always found in the dark period regardless of whether or not division had paused at the same time.

3. This result implied the inadequacy of applying the model of McDuff & Chisholm [Limnology and Oceanography (1982) vol. 27, pp. 783–787] directly to calculate the duration of cell division. Modified equations are proposed to calculate the duration of cytokinesis as a terminal event, in which the FDC values at night are regarded as 0% and all FDC values are subtracted by the minimum FDC value.

4. The diel FDC in natural populations of M. aeruginosa and M. wesenbergii were examined at five sites from a harbour to several distances offshore in Lake Biwa. While both species showed phased cell division patterns in the daytime at the harbour, no peaks in FDC were discernible in the samples taken from the offshore sites. These results strongly suggested that Microcystis growth was higher inshore than offshore. The in situ growth rates were estimated using the new equations.
Evolutionary trends and patterns in centipede segment number based on a cladistic analysis of Mecistocephalidae (Chilopoda: Geophilomorpha)
Authors: Bonato Lucio , Foddai Donatella , Minelli Alessandro
Published: October 2003

Abstract. Evolutionary changes in segment number during the radiation of Mecistocephalidae, a group of geophilomorph centipedes with segment number usually invariant at the species level, were explored based on a cladistic analysis of forty‐six mecistocephalid species, representative of the extant diversity in segment number. The data matrix included 118 morphological characters. Trends were recognized in the evolution of segment number and discussed in relation to the underlying ontogenetic mechanisms of segmentation. The basic trend was towards an increasingly higher number of leg‐bearing segments, from (most probably) forty‐one to sixty‐five (101 in one exceptional case). Changes always involved even sets of segments. Additions of two, four or eight segments usually occurred, but a case of overall duplication of the whole number was also documented. Most changes occurred starting from values belonging to the arithmetical series forty‐one, forty‐five, forty‐nine, whereas the intermediate values forty‐three, forty‐seven, fifty‐one were often evolutionary dead‐ends. This evidence suggests a multiplicative mechanism of segmentation involving one or more final run of duplication, as well as a precise control of the final number of segments which produces absolute number stability, except for a single, highly derived species with an exceptionally high number of segments. These ideas contribute to a more general model of arthropod segmentation recently developed by Minelli. A taxonomic revision of mecistocephalids is presented: three subfamilies are proposed (Arrupinae, Dicellophilinae and Mecistocephalinae) andSundarrupis recognized as a junior synonym ofAnarrup.
Phylogeny of Syrphidae (Diptera) inferred from combined analysis of molecular and morphological characters
Authors: Ståhls Gunilla , Hippa Heikki , Rotheray Graham , Muona Jyrki , Gilbert Francis
Published: October 2003

Abstract.  Syrphidae (Diptera) commonly called hoverflies, includes more than 5000 species world‐wide. The aim of this study was to address the systematic position of the disputed elements in the intrafamilial classification of Syrphidae, namely the monophyly of Eristalinae and the placement of Microdontini and Pipizini, as well as the position of particular genera (Nausigaster, Alipumilio, Spheginobaccha). Sequence data from nuclear 28S rRNA and mitochondrial COI genes in conjunction with larval and adult morphological characters of fifty‐one syrphid taxa were analysed using optimization alignment to explore phylogenetic relationships among included taxa. A species of Platypezidae, Agathomyia unicolor, was used as outgroup, and also including one representative (Jassidophaga villosa) of the sister‐group of Syrphidae, Pipunculidae. Sensitivity of the data was assessed under six different parameter values. A stability tree summarized the results. Microdontini, including Spheginobaccha, was placed basally, and Pipizini appeared as the sister‐group to subfamily Syrphinae. The monophyly of subfamily Eristalinae was supported. The results support at least two independent origins of entomophagy in syrphids, and frequent shifts between larval feeding habitats within the saprophagous eristalines.
Toxic lactonic lipopeptide from food poisoning isolates of Bacillus licheniformis
Authors: Mikkola Raimo , Kolari Marko , Andersson Maria A. , Helin Jari , Salkinoja‐Salonen Mirja S.
Published: October 2003

Toxins from three Bacillus licheniformis strains connected to a fatal food poisoning were isolated and their structures elucidated. Toxins were purified from methanol extracts of the B. licheniformis biomass using boar sperm cells as the toxicity indicator. The HPLC purified toxins showed protonated masses m/z 1007, 1021 and 1035 in MALDI‐TOF‐MS. The toxins isolated from the strains of different origins contained the same three components of which and each had a same amino‐acid residues l‐Gln, l‐Leu, d‐Leu, l‐Val, l‐Asp, d‐Leu and l‐Ile in that order. Toxins were identified as lichenysin A, a cyclic lactonic heptalipopeptide in which the main 3‐hydroxy fatty acids are 13–15 carbons in length. We showed that the toxins from food and food poisoning isolates of B. licheniformis were identical to lichenysin A both in the structure and in the toxic symptoms induced to boar spermatozoa. Confocal laser scanning microscopy showed that the acrosome and the plasma membrane of boar spermatozoa were the targets of lichenysin A toxicity.
Arsenate transport and reduction in the hyper‐tolerant fungus Aspergillus sp. P37
Authors: Cánovas David , Mukhopadhyay Rita , Rosen Barry P. , De Lorenzo Víctor
Published: October 2003

Aspergillus sp. P37 is able to grow at arsenate concentrations of 0.2 M – more than 20‐fold higher than that withstood by reference microorganisms such Escherichia coli, Saccharomyces cerevisiae and Aspergillus nidulans. This paper examines the transport of arsenate and phosphate and the reduction of arsenate in Aspergillus sp. P37. These properties were compared with the corresponding properties of the archetype strain Aspergillus nidulans TS1. Both uptake and efflux of arsenate were inhibited by carbonyl cyanide‐p‐trifluoromethoxyphenylhydrazone, suggesting that the transport system(s) is(are) membrane‐potential dependent. As uptake of arsenate and phosphate are higher in Aspergillus sp. P37 than in A. nidulans, the increase in arsenate resistance cannot be accounted for by a change in uptake. Cells of both strains loaded with arsenic slowly released the oxyanion. Speciation of the arsenic in the medium showed an enhanced level of arsenate reduction in Aspergillus sp. P37. These data suggest that increased arsenate reduction is at least in part responsible for the hyper‐tolerant phenotype of this fungus.
Isolation of Halobacterium salinarum retrieved directly from halite brine inclusions
Authors: Mormile Melanie R. , Biesen Michelle A. , Gutierrez M. Carmen , Ventosa Antonio , Pavlovich Justin B. , Onstott Tullis C. , Fredrickson James K.
Published: October 2003

Halite crystals were selected from a 186 m subsurface core taken from the Badwater salt pan, Death Valley, California to ascertain if halophilic Archaea and their associated 16S rDNA can survive over several tens of thousands of years. Using a combined microscope microdrill/micropipette system, fluids from brine inclusions were aseptically extracted from primary, hopper texture, halite crystals from 8 and 85 metres below the surface (mbls). U‐Th disequilibrium dating indicates that these halite layers were deposited at 9600 and 97 000 years before present (ybp) respectively. Extracted inclusions were used for polymerase chain reaction (PCR) analysis with haloarchaea‐specific 16S rDNA primers or placed into haloarchaea culture medium. Enrichment cultures were obtained from 97 kyr halite crystal inclusion fluid and haloarchaea‐containing prepared crystals (positive controls), whereas inclusions from crystals of 9.6 kyr halite and the haloarchaea‐free halite crystals (negative controls) resulted in no growth. Phylogenetic analysis (16S rDNA) of the 97 kyr isolate, designated BBH 001, revealed a homology of 100% with Halobacterium salinarum. DNA–DNA hybridization experiments confirmed that BBH 001 was closely related to H. salinarum (81–75% hybridization) and its ascription to this haloarchaea species. The described method of retrieving particle‐containing brine from fluid inclusions offers a robust approach for assessing the antiquity of microorganisms associated with evaporites.
The significance of organic carbon compounds for in situ metabolism and chemotaxis of phototrophic consortia
Authors: Glaeser Jens , Overmann Jörg
Published: October 2003

The significance of organic carbon substrates for the chemotaxis and physiology of phototrophic consortia was investigated in a dense chemocline community of Pelochromatium roseum. For the first time, the monopolar monotrichous flagellation of the central bacterium could be visualized. In situ, intact motile P. roseum consortia were strongly attracted by sulphide and 2‐oxoglutarate, which indicated a potential role of these compounds in the metabolism of P. roseum. In chemocline water samples, 2‐[14C(U)]‐oxoglutarate was utilized at nanomolar concentrations (half saturation constant of uptake Kt£ 10–40 nM), and at a maximum uptake rate of Vmax ª 6 nM h−1. The calculated turnover of 2‐oxoglutarate at in situ concentrations was ∼6 h. Microautoradiography of chemocline water samples revealed that 87.5% of the P. roseum consortia incorporated 2‐oxoglutarate when both light and sulphide were present, whereas uptake was detected in less than 1.4% of the consortia if either light or sulphide were absent. Because the green sulphur bacterial epibionts in P. roseum have been shown to grow autotrophically, 2‐oxoglutarate most likely is taken up and utilized by the central bacterium. Thus, our results indicate that incorporation of 2‐oxoglutarate by the central bacterium is regulated by the metabolic state of the green sulphur bacterial epibionts.
Phylogenetic analysis of the microbial populations in the wild herbivore gastrointestinal tract: insights into an unexplored niche
Authors: Nelson Karen E. , Zinder Stephen H. , Hance Ioana , Burr Patrick , Odongo David , Wasawo Delia , Odenyo Agnes , Bishop Richard
Published: October 2003

At present, there is little information on the phylogenetic diversity of microbial species that inhabit the gastrointestinal tracts of wildlife. To increase understanding in this area, we initiated a characterization of the bacterial diversity in the digestive tracts of three wild African ruminant species namely eland (Taurotragus oryx), Thompson's gazelle (Gazella rufifrons) and Grant's gazelle (Gazella granti), together with a domesticated ruminant species, zebu cattle (Bos indicus), and a non‐ruminant species, zebra (Equus quagga). Bacterial diversity was analysed by PCR amplification, sequencing and phylogenetic analysis of 16S ribosomal DNA (rDNA) sequences. A total of 252 full‐length 16S rDNA sequences averaging 1500 base pairs (bp) in length, and an additional 27 partial sequences were obtained and subject to phylogenetic analysis. Using a 98% criterion for similarity, all except for one of the sequences were derived from distinct phylotypes. At least 24 distinct operational taxonomic units (OTU′s) could be identified, with the majority of these sequences representing hitherto uncharacterized species and genera. The sequences were generally affiliated with four major bacterial phyla, the majority being members of the Firmicutes (low G+C Gram‐positives) related to the genera Clostridium and Ruminococcus. By contrast, with earlier studies using 16S rDNA sequences to assess biodiversity in Bos taurus dairy cattle, Gram‐negative bacteria in the Bacteroidales (Prevotella‐Bacteroides group) were poorly represented. The lack of redundancy in the 16S rDNA dataset from the five African ungulate species, and the presence of novel sequences not previously described from the gastrointestinal tract of any animal species, highlights the level of diversity that exists in these ecosystems and raises the question as to the functional role of these species in the gastrointestinal tract.
Cell density related H2 consumption in relation to anoxic Fe(0) corrosion and precipitation of corrosion products by Shewanella oneidensis MR‐1
Authors: De Windt Wim , Boon Nico , Siciliano Steven D. , Verstraete Willy
Published: October 2003

In the absence of oxygen, a protective H2 film is formed around an Fe(0) surface, inhibiting the electron flow from this surface. Our study of anoxic corrosion of Fe(0) beads revealed that, in the presence of Shewanella oneidensis MR‐1, H2 removal and precipitation of Fe mineral particles on the cell surface are determining processes for corrosion. These two biologically mediated processes were governed by cell density. H2 removal by Shewanella oneidensis was detected at cell concentrations of 1.0 × 106 live cells ml−1 and higher and H2 was electron donor for denitrification of NO3–. The removal of the protective H2 layer from Fe(0) beads by Shewanella oneidensis, resulted in an increase of Fe release out of the Fe(0) beads from 153 ± 25 mg l−1 to 196 ± 7 mg l−1 after 20 h. When the cell concentration exceeded 1.0 × 108 live cells ml−1, precipitation of iron minerals on the cell surface was characteristic for the greatest percentage of MR‐1 cells, whereas micrometre‐scale iron precipitates not associated with culturable cell biomass significantly decreased in number. Addition of supernatant of a corrosion assay with high cell concentration induced metabolic activity in a corrosion assay with low cell concentration, resulting in increased H2 consumption and Fe release from Fe(0) beads. Homoserine lactone‐like molecules were detected in the supernatant by a bio‐assay, suggesting the involvement of a quorum‐sensing regulatory mechanism.
In vitro effects of ultraviolet A on histamine release from human basophils
Authors: Monfrecola G , De Paulis A , Prizio E , Russo I , Carfora M , Santoianni P , Marone G
Published: October 2003

Background  As long‐wave ultraviolet (UV) radiation penetrates the dermis, connective tissue cellular components and circulating blood cells can be possible targets for solar UVA. Basophils, involved in the effector phase of the inflammatory response, play a part in skin diseases such as chronic urticaria, psoriasis, atopic dermatitis, fixed drug eruption, allergic contact dermatitis, urticaria pigmentosa, systemic sclerosis and bullous pemphigoid.

Objective  The evaluation of the in vitro effect of UVA on histamine release from human basophils.

Methods  Basophils from healthy human volunteers were irradiated, respectively, with UVA at doses of 2.5, 5, 7.5, 10, 20 and 50 J/cm2 and then incubated with an anti‐IgE serum. A fluorimetric technique was employed to determine histamine release from samples: (i) incubated with 2% HClO4 (complete lysis of basophils); (ii) irradiated with increasing doses of UVA; and (iii) unirradiated (controls).

Results  Histamine release was: 100% for HClO4 incubated basophils, 30% for unirradiated and anti‐IgE incubated cells (controls) and 27%, 24%, 34%, 41%, 60% and 70% for basophils irradiated with UVA doses, respectively, of 2.5, 5, 7.5, 10, 20 and 50 J/cm2 and incubated with anti‐IgE. Histamine releasability from irradiated samples was statistically significant (P < 0.05), in comparison with controls, at UVA doses equal to 5, 10, 20 and 50 J/cm2.

Conclusions  UVA exerts, at least in vitro, a biphasic dose‐dependent action on histamine release from human basophils incubated with an anti‐IgE serum: at the lowest irradiation doses (< 5 J/cm2) it exerts an inhibitory effect and at the highest doses ( 10 J/cm2) histamine release increases significantly.
Granuloma annulare in a site of healed herpes zoster: Wolf's isotopic response
Authors: Ruocco E , Baroni A , Cutrì F Tripodi , Filioli F Grimaldi
Published: October 2003

A case of granuloma annulare that developed in a site of healed herpes zoster is reported. Polymerase chain reaction failed to detect VZV DNA in a biopsy specimen. The occurrence of different types of cutaneous reactions in a body area previously affected by herpes virus infection is known as Wolf's isotopic response. Pathogenesis may be due to a local neuroimmune dysregulation set off by herpesvirus‐induced lesions of dermal sensory nerve fibres.
Stressful life events, anxiety, depression and coping mechanisms in patients with Behçet's disease
Authors: Karlidag R , Unal S , Evereklioglu C , Sipahi B , Er H , Yologlu S
Published: October 2003

Background  Behçet's disease is a systemic immunoinflammatory disease of young adults characterized by systemic vasculitis of arteries and veins. Although many studies have been published since its discovery in 1937, the etiopathogenesis of this unique disorder is still unclear.

Objective  To assess the relationship between stress factors, psychological and somatic symptoms, and coping mechanisms in patients with Behçet's disease.

Method  Thirty‐four patients with Behçet's disease and 43 control subjects were compared by using sociodemographic data collection forms, a psychosocial and environmental problems list, the Beck Anxiety Inventory (BAI), Hamilton Depression Rating Scale (HAM‐D) and Toronto Alexithymia Scale (TAS).

Results  Twenty‐four patients (70.6%) defined stress factors in the first stage of the disease. Twenty‐seven (79.4%) out of 34 patients stated that the recurrence period of the disease was related to the stress factors. Fear was expressed by 10 (29.4%) patients, sadness by 11 (32.3%), and fear plus sadness by 13 (38.2%) when they first learnt the diagnosis. While coping with these emotions 14 (41.2%) revealed active‐reliance strategy. A statistically significant difference was present between the Behçet's patients and control subjects regarding TAS (P < 0.05), HAM‐D (P < 0.001) and BAI (P < 0.001) scores.

Conclusion  It seems that stressful life events have important implications in both relapsing and remission periods of Behçet's disease via secondary problems.
Fabry disease: enzyme replacement therapy
Authors: Bongiorno MR , Pistone G , Aricò M
Published: October 2003

Fabry disease is a multisystem disorder associated with wide variability in clinical expression. Fabry disease is an X‐linked lysosomal storage disorder caused by a deficiency of α‐galactosidase A. The enzyme defect leads to the systemic accumulation of glycosphingolipids with α‐galactosyl moieties consisting predominantly of globotriaosylceramide, galabiosylceramide and two additional glycosphingolipids.

Four hemizygotes patients with a family history of Fabry disease and deficiency of the enzyme α‐galactosidase A were selected. Each patient received purified α‐galactosidase by intravenous infusion (0.2 mg/kg). The infusion was administered every 2 weeks, for 40 min, for a total of 12 months. Outcome measures include neurological manifestations (acroparaesthesia, hypohidrosis, vasomotion), kidney function, cardiac manifestations, angiokeratomas, and corneal dystrophy.

α‐Galactosidase A prepared from human fibroblast is safe and well tolerated. After 12 months of therapy the mean creatinine clearance increased, there was significant improvement in the acroparaesthesias and in the hypohidrosis. Physical stigmata, such as angiokeratomas in the skin, and characteristic benign corneal abnormalities remained stable.

Enzyme replacement therapy would therefore represent a significant advance in treatment of patients with Fabry disease. Enzyme replacement therapy is safe and likely to improve the prognosis of Fabry disease.