bluuebunny/crossref_metadata_2025 huggingface dataset:
The diversity of life‐form type, habitat preference and phenology of the endemics in the Goa region of the Western Ghats, India
Authors: Joshi Vaishali C. , Janarthanam M. K.
Published: July 2004

Aim To carry out (1) a floristic survey of endemic flowering plants of the Western Ghats occurring in Goa, (2) identify their habitat preference and diversity of life‐form type, (3) observe flowering phenology of the endemics and (4) to correlate factors that affect their phenological pattern.

Location Goa state is located between 15°48′ N and 14°53′54′′ N and 74°20′13′′ E and 73°40′33′′ E, in the northern part of the Western Ghats, India.

Method A list of endemic plants from the study area was prepared using available floristic works and checklists of endemic plants of India. Based on preliminary field observations carried out in the study area, major habitats such as plateaus, moist deciduous forests, semi‐evergreen forests, evergreen forests and mangroves were identified for the subsequent intensive survey of endemics. Voucher specimens for all the endemic species were collected, processed using conventional herbarium techniques and deposited in the Herbarium, Department of Botany, Goa University. Species were identified using local and regional floras and their identity was confirmed at various herbaria along the Western Ghats. Data on their life‐form types, habitat and phenology was recorded in the field. Phenological observations were made every fortnight. A computerized data base was generated incorporating details on their life‐form type, phenology and habitat.

Results A floristic survey of endemic plants of the Western Ghats in Goa resulted in the collection of 113 endemic species. Life‐form analysis reveals that herbaceous endemics are the most dominant followed by trees, shrubs and climbers. Plateaus in the study area harbour the largest number of endemic species, especially herbs. Endemic trees are distributed in the semi‐evergreen and evergreen forests. Endemic species in the study area show different peak and lean seasons of flowering depending on their life‐form type, habitat and ecological factors like temperature and rainfall/moisture content in the soil.

Main conclusions The plateaus in the northern part of the Western Ghats are unique, being species rich with herbaceous endemics. These ephemerals are closely associated with the rainfall patterns thus; any change of moisture regime over the long‐term will have an impact on the distribution of these endemics.
Rain forest invasion of eucalypt‐dominated woodland savanna, Iron Range, north‐eastern Australia: I. Successional processes
Authors: Russell‐Smith Jeremy , Stanton Peter J. , Whitehead Peter J. , Edwards Andrew
Published: July 2004

Aim  To explore successional processes associated with rain forest expansion in Eucalyptus‐dominated woodland savanna vegetation in north‐eastern Australia.

Location  Iron Range National Park and environs, northeast Queensland, Australia. This remote region supports probably the largest extent of lowland (< 300 m) rainforest remnant in Australia. Rainfall (c. 1700 mm p.a.) occurs mostly between November and June, with some rain typically occurring even in the driest months July–October.

Methods  (1) Sampling of rain forest seedling distributions, and other vegetation structural attributes, in fifteen 10 × 10 m quadrats distributed equi‐distantly between mature rain forest margins (range: 70–840 m), at each of 10 sites which were open‐canopied vegetation in 1943. (2) Assessment of relationships between rain forest seedling densities and structural characteristics, including distance‐to‐rain forest‐margin, canopy height, stem density. (3) Assessment of lifeform and dispersal spectra for defined vegetation structural types.

Results  Rates of rain forest invasion were found to be substrate‐mediated. Transects established on hematite schist, diorite, riverine alluvium, and granite developed closed canopies (termed phase III sites) by 1991. The remainder (four transects on poorly drained colluvial/alluvial sediments; one on dune sands) continued to occur either as grassy woodland (phase I), or with developing rain forest understoreys (phase II). Rain forest seedlings were observed at maximum sampled distances from mature rain forest margins at all sites. Lifeform and dispersal spectra data illustrated that: (1) the proportions of woodland trees, shrubs and graminoids declined with successional phase, with concomitant increases in rain forest primary trees and all other lifeform categories save rain forest trees; (2) the proportions of major dispersal syndromes did not vary between successional phases, neither for rain forest nor woodland taxa.

Main conclusions  Rain forest seedling distribution data for phases I and II sites illustrate three successional processes: margin extension – seedling density significantly negatively correlated with distance from mature rain forest margins at two sites; nucleation – seedling densities significantly positively correlated with tall trees at two sites; and irruption – seedling densities at two sites neither correlated with distance from mature rain forest margins, nor with measured vegetation structural features. The observation of irruptive rain forest regeneration at these sites, combined with decadal‐scale rain forest canopy development at the five remaining sites, illustrates that under conditions conducive to growth (moisture, substrate), low fire disturbance, and maintenance of diverse dispersal processes (high frugivore richness), rain forest can rapidly invade regional landscapes.
Distribution of basic diploid and polyploid species of Isoetes in East Asia
Authors: Liu Xing , Gituru Wahiti Robert , Wang Qing‐Feng
Published: July 2004

Aims  Isoetes L. is an ancient, primitive genus of heterosporous lycopsids characterized by a strongly reduced plant. The genus occupies a unique position in plant evolution as the closest relatives of the famous tree lycopods. Hybridization and allopolyploid speciation as well as habitat preference are regarded as having played an important role in the evolution of the genus Isoetes. However, it is still uncertain what factors have impacted upon hybridization and allopolyploid speciation of the genus Isoetes. Our understanding of the origin, evolution and modern distribution pattern of Isoetes in East Asia would benefit from investigations into the relationship between the unique geographical location and topographic features and the existing fossil record in the region.

Methods  The chromosome number was determined from known 81 populations of 10 species of Isoetes in East Asia. The altitude was obtained in location of every population. T‐test was used to evaluate the altitude difference between diploid and polyploid populations. Data of Japanese Isoetes from Takamiya et al. was used in the study.

Results  There are 10 known species of Isoetes with four diploids and six polyploids in East Asia. The four diploid species (2n = 22) are found at high altitudes (mean altitude = 2649.67 ± 1396.16 m, n = 18) and isolated from each other. In contrast, the six polyploid species widely occur in low altitude regions (mean altitude = 182.62 ± 181.44 m, n = 63) and are partially sympatric. Highly significant differences (P < 0.001) were observed between the mean altitude of locations of populations of diploids and polyploids.

Main conclusions  The polyploidy speciations of Isoetes in East Asia might originate and develop from Holocene (Quaternary). The present pattern of distribution of Isoetes in East Asia is the result of allopatric speciation derived from vicariance, dispersal and combinations of both, and significantly correlative with the geological history and geographical changes. The change of altitude might have played an important role in allopolyploid speciation and the pattern of distribution of the genus Isoetes in East Asia by exerting a considerable influence on dispersal and hybridization opportunities of Isoetes species.
A multi‐scale biogeographical analysis of Bambusa arnhemica, a bamboo from monsoonal northern Australia
Authors: Franklin Donald C. , Bowman David M. J. S.
Published: July 2004

Aims  To identify the edaphic, environmental and historical factors influencing the patchy distribution of the semelparous bamboo Bambusa arnhemica F. Muell. at global, catchment and streambank scales.

Location  The entire range of B. arnhemica, a highly fire‐prone savanna matrix with generally infertile soils in the north‐west of the Northern Territory of Australia above the 1200 mm mean annual rainfall isohyet.

Methods  Distribution surveys were conducted by air, boat and on the ground. Plot data were collected throughout the range of the species.

Results  Bambusa arnhemica occurred predominantly in gallery forests on flood‐prone but nevertheless well‐drained and deep alluvial soils on sloping stream banks. It ranged widely along lentic watercourses from ephemeral headwater streams to the banks of major rivers and levees on the coastal floodplain. The species did not occur in savannas; savannas adjacent to B. arnhemica gallery forests were also flood‐prone and on deep alluvial soils, but were upslope on level ground. Bambusa arnhemica's infrequent non‐riparian occurrences were on a wide variety of substrates but generally on soils of moderate fertility and in coastal and/or rocky areas where at least partial topographic protection from fire is likely. Within and between catchments, the distribution of B. arnhemica was idiosyncratic, occurrence being almost always continuous downstream from highly variable ‘starting’ points to the poorly drained coastal floodplain.

Main conclusions  At local scales, B. arnhemica appears constrained by poor drainage and high fire‐frequencies. Enhanced soil fertility may increase its capacity to cope with fire. At the catchment and global scales, we propose that the distribution of B. arnhemica is the product of infrequent and as yet incomplete dispersal across and away from watercourses by seed that lacks specialized dispersal mechanisms, combined with passive dispersal along streams. From this we infer that B. arnhemica is neither a very recent, nor very ancient colonist from Asia. Bambusa arnhemica's circumscribed global distribution has no parallel amongst co‐occurring rain forest plants and may be the product of poor dispersal capacity and a substantial rock and floodplain barrier to the east. Limited dispersal capacity may be inextricably linked to local domination of space and the subsequent creation of regeneration space by parental death.
The ED strategy: how species‐level surrogates indicate general biodiversity patterns through an ‘environmental diversity’ perspective
Authors: Faith D. P. , Ferrier S. , Walker P. A.
Published: July 2004

Biodiversity assessment requires that we use surrogate information in practice to indicate more general biodiversity patterns. ‘ED’ refers to a surrogates framework that can link species data and environmental information based on a robust relationship of compositional dissimilarities to ordinations that indicate underlying environmental variation. In an example analysis of species and environmental data from Panama, the environmental and spatial variables that correlate with an hybrid multi‐dimensional scaling ordination were able to explain 83% of the variation in the corresponding Bray Curtis dissimilarities. The assumptions of ED also provide the rationale for its use of p‐median optimization criteria to measure biodiversity patterns among sites in a region. M.B. Araújo, P.J. Densham & P.H. Williams (2004, Journal of Biogeography31, 1) have re‐named ED as ‘AD’ in their evaluation of the surrogacy value of ED based on European species data. Because lessons from previous work on ED options consequently may have been neglected, we use a corroboration framework to investigate the evidence and ‘background knowledge’ presented in their evaluations of ED. Investigations focus on the possibility that their weak corroboration of ED surrogacy (non‐significance of target species recovery relative to a null model) may be a consequence of Araújo et al.'s use of particular evidence and randomizations. We illustrate how their use of discrete ED, and not the recommended continuous ED, may have produced unnecessarily poor species recovery values. Further, possible poor optimization of their MDS ordinations, due to small numbers of simulations and/or low resolution of stress values appears to have provided a possible poor basis for ED application and, consequently, may have unnecessarily favoured non‐corroboration results. Consideration of Araújo et al.'s randomizations suggests that acknowledged sampling biases in the European data have not only artefactually promoted the non‐significance of ED recovery values, but also artefactually elevated the significance of competing species surrogates recovery values. We conclude that little credence should be given to the comparisons of ED and species‐based complementarity sets presented in M.B. Araújo, P.J. Densham & P.H. Williams (2004, Journal of Biogeography31, 1), unless the factors outlined here can be analysed for their effects on results. We discuss the lessons concerning surrogates evaluation emerging from our investigations, calling for better provision in such studies of the background information that can allow (i) critical examination of evidence (both at the initial corroboration and re‐evaluation stages), and (ii) greater synthesis of lessons about the pitfalls of different forms of evidence in different contexts.
Influence of smoking and snus on the prevalence and incidence of type 2 diabetes amongst men: the northern Sweden MONICA study
Authors: Eliasson M. , Asplund K. , Nasic S. , Rodu B.
Published: July 2004

Objective.  To explore the effect of smoking and smokeless tobacco, ‘snus’, on the risk of type 2 diabetes.

Design.  Population‐based cross‐sectional and prospective follow‐up study in northern Sweden.

Subjects.  A total of 3384 men, aged 25–74 years, who participated in the MONICA study in 1986, 1990, 1994 or 1999, 1170 of whom had an oral glucose tolerance test. In 1999, 1757 men from previous cohorts returned for re‐examination.

Main outcome measures.  We compared the prevalence of type 2 diabetes or pathological glucose tolerance (PGT) amongst tobacco users to that of nonusers at entry into the study and at follow‐up, using odds ratios.

Results.  Compared with never users, the age‐adjusted risk of prevalent clinically diagnosed diabetes for ever smokers was 1.88 (CI 1.17–3.0) and for smokers 1.74 (0.94–3.2). Corresponding odds ratios for snus users were 1.34 (0.65–2.7) and 1.18 (0.48–2.9). We found no increased risk of prevalent PGT in snus users or smokers. Former smokers and snus users had an insignificantly increased risk for PGT. Compared with nonusers, the age‐adjusted risk of developing clinically diagnosed diabetes during follow‐up was 4.63 (1.37–16) in consistent exclusive smokers, 3.20 (1.16–8.8) in ex‐smokers and no cases in consistent snus users. The risk of PGT during follow‐up was not increased in consistent tobacco users but evident, although not statistically significant, in those who quit snus during the follow‐up period, 1.85 (0.60–5.7). Adjustment for physical activity and alcohol consumption did not change the major findings.

Conclusions.  The risk of diabetes for snus users was not significantly increased. Smoking was associated with prevalent and incident cases of diabetes. Ex‐tobacco users tended towards more PGT.
Low‐grade inflammation, endothelial activation and carotid intima‐media thickness in type 2 diabetes
Authors: Leinonen E. S. , Hiukka A. , Hurt‐Camejo E. , Wiklund O. , Sarna S. S. , Mattson Hultén L. , Westerbacka J. , Salonen R. M. , Salonen J. T. , Taskinen M.‐R.
Published: July 2004

Objectives.  The objective of this study was to assess the relationship between inflammation, endothelial activation and incipient atherosclerosis in type 2 diabetes.

Design.  Cross‐sectional study.

Setting and subjects.  We studied 239 type 2 diabetic patients [71 with clinical cardiovascular disease (CVD)] and 78 healthy control subjects, aged 50–75 in a single research centre.

Methods.  Carotid intima‐media thickness (IMT) was determined by ultrasound. Circulating intracellular adhesion molecule‐1, vascular cell adhesion molecule‐1, E‐selectin, ultra‐sensitive C‐reactive protein, human serum amyloid A, interleukin‐6, monocyte colony‐stimulating factor, secretory nonpancreatic phospholipase A2 type IIA, glucose, HbA1c, and lipid/lipoprotein variables were measured.

Results.  Carotid IMT was significantly thicker in diabetic patients than healthy controls across the whole age range. IMT was also thicker in diabetic patients with, than without, CVD, but this difference disappeared after controlling for confounding factors. Concentrations of the inflammatory and endothelial markers except IL‐6 were significantly higher in the diabetic patients than in healthy controls, but comparable in diabetic patients with and without CVD. The main determinants of IMT in the diabetic patients were blood pressure, age and diabetes duration.

Conclusions.  Low‐grade inflammation and endothelial activation are increased in diabetic patients but do not associate with IMT or clinical CVD. The inflammatory reaction seems to be rather a feature of the metabolic syndrome than a direct determinant of atherosclerosis.
Leptin, but not adiponectin, predicts stroke in males
Authors: Söderberg S. , Stegmayr B. , Stenlund H. , Sjöström L.‐G. , Ågren Å. , Johansson L. , Weinehall L. , Olsson T.
Published: July 2004

Objective.  To test whether leptin and adiponectin are risk markers for a first‐ever stroke.

Research design, methods and subjects.  A nested case‐referent study identified 276 cases with first‐ever stroke (234 cases with ischaemic and 42 with haemorrhagic stroke). Prior to the stroke, they had participated in population‐based health surveys in northern Sweden (median time between survey and stroke was 4.9 years). Referents were matched for sex, age, date and type of health survey, and geographical region. Putative risk markers for first‐ever stroke, including blood pressure (BP), diabetes, smoking, body mass index (BMI), cholesterol, leptin, and adiponectin, were analysed by conditional logistic regression analysis.

Results.  Increased BMI, high cholesterol and fasting glucose levels, diabetes mellitus and hypertension were found in future stroke patients. Whereas leptin levels were higher in male subjects (P = 0.004), adiponectin did not differ between groups. A high leptin level independently predicted stroke in men (OR = 2.46; 95% CI 1.08–5.62) but not in women. Adiponectin levels did not predict stroke. Males with high leptin levels developed stroke faster than males with low leptin levels (P = 0.0009), independently of traditional risk factors.

Conclusions.  Leptin may be an important link to the development of cerebrovascular disease in men, whereas adiponectin does not associate with future stroke.
Improving the outcomes of anticoagulation: an evaluation of home follow‐up of warfarin initiation
Authors: Jackson S. L. , Peterson G. M. , Vial J. H. , Jupe D. M. L.
Published: July 2004

Objectives.  A number of studies have reported that the risk of bleeding associated with warfarin is highest early in the course of therapy. This study examined the effect of a programme focused on the transition of newly anticoagulated patients from hospital to the community.

Design.  Open‐label randomized controlled trial.

Setting.  Home‐based follow‐up of patients discharged from acute care hospital in southern Tasmania, Australia.

Subjects.  A total of 128 patients initiated on warfarin in hospital and subsequently discharged to general practitioner (GP) care were enrolled in the study. Sixty were randomized to home monitoring (HM) and 68 received usual care (UC).

Interventions.  HM patients received a home‐visit by the project pharmacist and point‐of‐care international normalized ratio (INR) testing on alternate days on 4 occasions, with the initial visit two days after discharge. The UC group was solely managed by the GP and only received a visit 8 days after discharge to determine anticoagulant control.

Results.  At discharge, 42% of the HM group and 45% of the UC group had a therapeutic INR. At day 8, 67% of the HM patients had a therapeutic INR, compared with 42% of UC patients (P < 0.002). In addition, 26% of UC patients had a high INR, compared with only 4% of HM patients. Bleeding events were assessed 3 months after discharge and occurred in 15% of HM patients, compared with 36% of the UC group (P < 0.01).

Conclusions.  This programme improved the initiation of warfarin therapy and resulted in a significant decrease in haemorrhagic complications in the first 3 months of therapy.
Is the placebo powerless? Update of a systematic review with 52 new randomized trials comparing placebo with no treatment
Authors: Hróbjartsson A. , Gøtzsche P. C.
Published: July 2004

Background.  It is widely believed that placebo interventions induce powerful effects. We could not confirm this in a systematic review of 114 randomized trials that compared placebo‐treated with untreated patients.

Aim.  To study whether a new sample of trials would reproduce our earlier findings, and to update the review.

Methods.  Systematic review of trials that were published since our last search (or not previously identified), and of all available trials.

Results.  Data was available in 42 out of 52 new trials (3212 patients). The results were similar to our previous findings. The updated review summarizes data from 156 trials (11 737 patients). We found no statistically significant pooled effect in 38 trials with binary outcomes, relative risk 0.95 (95% confidence interval 0.89–1.01). The effect on continuous outcomes decreased with increasing sample size, and there was considerable variation in effect also between large trials; the effect estimates should therefore be interpreted cautiously. If this bias is disregarded, the pooled standardized mean difference in 118 trials with continuous outcomes was −0.24 (−0.31 to −0.17). For trials with patient‐reported outcomes the effect was −0.30 (−0.38 to −0.21), but only −0.10 (−0.20 to 0.01) for trials with observer‐reported outcomes. Of 10 clinical conditions investigated in three trials or more, placebo had a statistically significant pooled effect only on pain or phobia on continuous scales.

Conclusion.  We found no evidence of a generally large effect of placebo interventions. A possible small effect on patient‐reported continuous outcomes, especially pain, could not be clearly distinguished from bias.
A patient withTSC1germline mutation whose clinical phenotype was limited to lymphangioleiomyomatosis
Authors: Sato T. , Seyama K. , Kumasaka T. , Fujii H. , Setoguchi Y. , Shirai T. , Tomino Y. , Hino O. , Fukuchi Y.
Published: July 2004

Background: Lymphangioleiomyomatosis (LAM) can occur as in isolated form (sporadic LAM) or as a pulmonary manifestation of tuberous sclerosis complex (TSC) (TSC‐associated LAM). Recent studies, however, revealed that both forms of LAM are genetically related but that sporadic LAM is a distinct clinical entity caused by somatic mutations ofTSC2(notTSC1) rather than a forme fruste of TSC carrying either of theTSC1orTSC2germline mutations.

Method: Case presentation and in‐depth molecular and histopathological examinations. A 34‐year‐old Japanese woman was diagnosed as having pulmonary lymphangioleiomyomatosis (LAM) when bilateral pneumothoraces were surgically treated in 1992. Although slowly progressive renal disfunction was observed due to bilateral multiple renal cysts during the past 4 years, she had no other clinical features of TSC and was diagnosed as having sporadic LAM with multiple renal cysts of undetermined aetiology. Her subsequent clinical course was complicated by an endobrochial carcinoid tumour, which eventually resulted in her death in June 1999 due to massive haemoptysis.

Results: Postmortem examination revealed the presence of LAM lesions in the lungs, mediastinal lymph nodes, kidneys and uterus. Diffuse renal LAM lesions are presumed to generate multiple renal cysts by constricting the nephron rather than epithelial hyperplasia obstructing lumina, which is analysis of theTSCgenes demonstrated that she did not haveTSC2/PKD1contiguous gene syndrome but had aTSC1 germline mutation (Sato Tet al. J Hum Genet 2002;47: 20–8) that had occuredde novo.

Conclusion: This patient therefore illustrates that clinical manifestations of TSC are sufficiently diverse as to allow a forme fruste of TSC that mimics sporadic LAM and thatTSC1 mutation can cause multiple renal cysts resulting in renal failure.
Trends in the incidence of chronic Philadelphia chromosome negative (Ph‐) myeloproliferative disorders in the city of Göteborg, Sweden, during 1983–99
Authors: Johansson P. , Kutti J. , Andréasson B. , Safai‐Kutti S. , Vilén L. , Wedel H. , Ridell B.
Published: July 2004

Objective.  In the literature the incidence rates for the chronic Philadelphia chromosome negative (Ph‐) myeloproliferative disorders (MPD) are known to vary extensively; only a few studies have, however, been concerned with incidence trends over time. Therefore, the aim of the present work was to investigate possible trends as regards incidence rates over time for Ph‐MPD.

Design.  Herein, we carried out a retrospective population‐based survey on the incidence of polycythaemia vera (PV), essential thrombocythae‐mia (ET) and chronic idiopathic myelofibrosis (IMF), in the city of Göteborg (Sweden), covering the years 1983–99.

Results.  The study comprised 416 patients with Ph‐MPD. There were 205 patients with PV, 153 patients with ET, 34 with IMF and 24 with unclassified MPD. The annual incidence for PV was 1.97 per 105 inhabitants; the corresponding figures for ET and IMF were 1.55 per 105 and 0.30 per 105 inhabitants, respectively. There was a significant increase in the annual incidence rate for ET (P = 0.008); this increase was significant for male subjects (P = 0.015) but did not reach significance for females (P = 0.118). No such increase over time was recorded as regards PV and IMF.

Conclusions.  The increasing annual incidence rate for ET is most possibly explained by the more frequent use of automated platelet counts whenever a patient consults a doctor. Thereby, an increasing number of patients with overt thrombocytosis of unknown origin are discovered and will be referred to specialists within the field of haematology for a correct diagnosis.
Effect of plasma arc curing on polymerization shrinkage of orthodontic adhesive resins
Authors: Bang H.‐C. , Lim B.‐S. , Yoon T.‐H. , Lee Y.‐K. , Kim C.‐W.
Published: July 2004

summary  The purpose of this study was to evaluate the polymerization shrinkage of three orthodontic adhesive resins when polymerized with a high‐energy plasma arc light (1340 mW cm−2) and a conventional halogen light (500 mW cm−2), and to correlate the polymerization shrinkage with the degree of conversion. To equalize the total light energy delivered to the adhesive resin, irradiation time was varied between 3 or 6 s for a plasma arc‐curing unit, and 8 or 16 s for a halogen light‐curing unit. The polymerization shrinkage of adhesive resins during the light‐curing process was measured using a computer‐controlled mercury dilatometer and the degree of conversion was measured using Fourier transform infrared spectroscopy. A plasma arccuring unit produced significantly lower polymerization shrinkage than a halogen light‐curing unit when the equivalent total light energy was irradiated to the orthodontic adhesive resins (P < 0·05). The magnitude of polymerization shrinkage was significantly different depending on the kind of adhesive resins (P < 0·05), but there was no significant correlation between the filler fraction and the polymerization shrinkage (r2 = 0·039). There was strong correlation (r2 = 0·787) between the polymerization shrinkage and the degree of conversion with a halogen light‐curing unit, but poor correlation (r2 = 0·377) was observed with a plasma arc‐curing unit.
Relationship between the TMJ disc and condyle position on MRI and occlusal contacts on lateral excursions in TMD patients
Authors: Taşkaya‐Yilmaz N. , Öğütcen‐Toller M. , Saraç Y. Ş.
Published: July 2004

summary  Confusion about the relationship between dental occlusion and the temporomandibular disorders (TMD) has been evident in the literature for many years. Previous studies have supported the concept of a multifactorial aetiology of TMD, the occlusal factor in general being of minor importance. The purpose of the study was to investigate the relationship between condyle and disc positions and occlusal contacts on lateral excursions of the mandible in patients with TMD. A total of 122 temporomandibular joints (TMJs) of 61 patients with TMD were evaluated using magnetic resonance imaging (MRI) and occlusal analyses were made clinically. Non‐working‐side contacts were found to be statistically significant in TMJ anterior disc displacement. No significant statistical correlation was found between the severity of anterior disc displacement and non‐working‐side contacts in both canine guidance and group function occlusions. There was no correlation between non‐working‐side contacts and condyle positions in both occlusion types in the present study. It was concluded that non‐working‐side contacts had some effect on disc position in TMD, however the presence of these contacts in both canine guidance and group function occlusions did not correlate with anterior disc displacement in TMD statistically. Therefore, non‐working‐side contacts are not to be regarded as the prime cause of anterior disc displacement.
Craniomandibular pain, oral parafunctions, and psychological stress in a longitudinal case study
Authors: van Selms M. K. A. , Lobbezoo F. , Wicks D. J. , Hamburger H. L. , Naeije M.
Published: July 2004

summary  In a single case study, the most frequently suggested contributing factors to craniomandibular pain, viz., oral parafunctions and psychological stress, were studied in more detail. During a 13‐week study period, questionnaires were completed, in which, among others, jaw muscle pain, bruxism behaviour, and experienced/anticipated stress were noted. During about 40% of the nights, nocturnal masticatory muscle activity (NMMA) was recorded, using single‐channel electromyography (EMG). The number of NMMA events per recorded hour was scored, using a detection threshold of 10% of the maximum voluntary contraction level. This threshold was established in a separate study, in which EMG was compared with polysomnography. Stepwise regression analyses indicated, that morning jaw muscle pain could be explained by evening jaw muscle pain for 64% and by alcohol intake for another 2%. In turn, evening jaw muscle pain was explained by daytime clenching for 56% and by vacuum sucking of the tongue for an additional 6%. Finally, daytime clenching was significantly explained by experienced stress for 30%. Data of the recorded nights showed, that variations in NMMA did not contribute to variations in morning jaw muscle pain. This case study corroborates the paradigm that experienced stress may be related to daytime clenching and, in turn, to evening and morning jaw muscle pain.
Pulp size in molars: underestimation on radiographs
Authors: Chandler N. P. , Pitt Ford T. R. , Monteith B. D.
Published: July 2004

summary  The aim was to determine whether radiographs provide a clinically useful indication of pulp size in diseased/restored human first molar teeth, and to investigate accessibility of pulp tissue for diagnostic testing using laser Doppler flowmetry (LDF). Extracted teeth of known age were collected. Restorative materials were removed and teeth with evidence of pulp exposures excluded. Fifty‐six teeth were radiographed from buccal and mesial aspects, and then their crowns were sectioned axiobuccolingually and photographed. Images were digitally scanned and measurements made of the total pulp area (above a line across the most superior part of the pulpal floor) and the pulp area in the clinical crown (superior to a line between the amelocemental junctions). The pulp width at the cervix and the highest point of the pulp were also recorded. Data were analysed using Pearson correlations. Pulp areas within the clinical crowns were significantly larger than indicated by radiographs, by 23% in the case of the clinically attainable buccal view (P < 0·05). Pulps may be more accessible to flowmeter testing than they appear. Absence of pulp tissues in the crown was recorded in equal numbers of teeth on radiographs and sections, but with agreement for only one tooth. Sixteen per cent of the teeth had no pulp area in the clinical crown when sectioned, but might still be suitable for testing using LDF.
Activity reversal of Tet repressor caused by single amino acid exchanges
Authors: Scholz Oliver , Henßler Eva‐Maria , Bail Johannes , Schubert Peter , Bogdanska‐Urbaniak Joanna , Sopp Sabine , Reich Marco , Wisshak Stefanie , Köstner Martin , Bertram Ralph , Hillen Wolfgang
Published: July 2004

We explore by extensive mutagenesis regions in the sequence allowing reversal of the allosteric response of Tet repressor. The wild type requires anhydrotetracycline for induction. About 100 mutants are presented, which, in contrast, require the drug for repression. Their mutations are clustered at the interface of the DNA‐ and inducer‐binding domains. This interface consists of a central hydrophobic region surrounded by several hydrogen bonds. While most of the mutants described here contain two to five mutations, we found five positions in this region of TetR, at which single amino acid exchanges lead to activity reversal. They may disrupt the hydrogen‐bonding network bordering the domain interface. We assume that the mutations cause a repositioning of the DNA reading head with respect to the effector binding core so that the same conformational change can result in opposite activities.
RovA is autoregulated and antagonizes H‐NS‐mediated silencing of invasin and rovA expression in Yersinia pseudotuberculosis
Authors: Heroven Ann Kathrin , Nagel Geraldine , Tran Hien J. , Parr Susanne , Dersch Petra
Published: July 2004

The transcriptional activator RovA of Yersinia pseudotuberculosis, a member of the SlyA/Hor family, activates its own expression and that of the virulence factor invasin in response to moderate growth temperature, but not at 37°C. In this work, we analysed the mechanism of RovA‐dependent transcription of the rovA and inv genes. We found that rovA is transcribed by two different promoters. Sequences located upstream and downstream of the promoters were involved in rovA autoregulation and interacted specifically with the RovA protein. To define the nucleotides recognized by the RovA protein, we determined the RovA binding sites in the rovA and the inv regulatory region and revealed related AT‐rich sequence motifs at diverse positions relative to the transcriptional start sites. We also showed that rovA and the RovA‐dependent inv gene were both subject to silencing by the nucleoid‐associated H‐NS protein of Y. pseudotuberculosis. The binding sites of the H‐NS and RovA proteins in the rovA and inv regulatory sequences were superimposed, and the presence of the RovA protein alleviated H‐NS‐mediated repression of the rovA and inv promoter. Moreover, loss of H‐NS function led to a significant increase in rovA and inv transcription nearly independently of RovA, indicating that RovA acts mainly as an antirepressor. We therefore hypothesize that the transcription level of RovA‐dependent genes reflects the outcome of the RovA/H‐NS competition and the rovA autoregulatory mechanism.
Tailoring modification of deoxysugars during biosynthesis of the antitumour drug chromomycin A3 by Streptomyces griseus ssp. griseus
Authors: Menéndez Nuria , Nur‐e‐Alam Mohammad , Braña Alfredo F. , Rohr Jürgen , Salas José A. , Méndez Carmen
Published: July 2004

Chromomycin A3 is a member of the aureolic acid group family of antitumour drugs. Three tailoring modification steps occur during its biosynthesis affecting the sugar moieties: two O‐acetylations and one O‐methylation. The 4‐O‐methylation in the 4‐O‐methyl‐D‐oliose moiety of the disaccharide chain is catalysed by the cmmMIII gene product. Inactivation of this gene generated a chromomycin‐non‐producing mutant that accumulated three unmethylated derivatives containing all sugars but differing in the acylation pattern. Two of these compounds were shown to be substrates of the methyltransferase as determined by their bioconversion into chromomycin A2 and A3 after feeding these compounds to a Streptomyces albus strain expressing the cmmMIII gene. The same single membrane‐bound enzyme, encoded by the cmmA gene, is responsible for both acetyl transfer reactions, which convert a relatively inactive compound into the bioactive chromomycin A3. Insertional inactivation of this gene resulted in a mutant accumulating a dideacetylated chromomycin A3 derivative. This compound, lacking both acetyl groups, was converted in a two‐step reaction via the 4E‐monoacetylated intermediate into chromomycin A3 when fed to cultures of S. albus expressing the cmmA gene. This acetylation step would occur as the last step in chromomycin biosynthesis, being a very important event for self‐protection of the producing organism. It would convert a molecule with low biological activity into an active one, in a reaction catalysed by an enzyme that is predicted to be located in the cell membrane.
Dimer‐induced signal propagation in Spo0A
Authors: Muchová K. , Lewis R. J. , Perečko D. , Brannigan J. A. , Ladds J. C. , Leech A. , Wilkinson A. J. , Barák I.
Published: July 2004

Spo0A, the response regulator protein controlling the initiation of sporulation in Bacillus, has two distinct domains, an N‐terminal phosphoacceptor (or receiver) domain and a C‐terminal DNA‐binding (or effector) domain. The phosphoacceptor domain mediates dimerization of Spo0A on phosphorylation. A comparison of the crystal structures of phosphorylated and unphosphorylated response regulators suggests a mechanism of activation in which structural changes originating at the phosphorylatable aspartate extend to the α4β5α5 surface of the protein. In particular, the data show an important role in downstream signalling for a conserved aromatic residue (Phe‐105 in Spo0A), the conformation of which alters upon phosphorylation. In this study, we have prepared a Phe‐105 to Ala mutant to probe the contribution of this residue to Spo0A function. We have also made an alanine substitution of the neighbouring residue Tyr‐104 that is absolutely conserved in the Spo0As of spore‐forming Bacilli. The spo0A(Y104A) and spo0A(F105A) alleles severely impair sporulation in vivo. In vitro phosphorylation of the purified proteins by phosphoramidate is unaffected, but dimerization and DNA binding are abolished by the mutations. We have identified intragenic suppressor mutations of spo0A(F105A) and shown that these second‐site mutations in the purified proteins restore phosphorylation‐dependent dimer formation. Our data support a model in which dimerization and signal transduction between the two domains of Spo0A are mediated principally by the α4β5α5 signalling surface in the receiver domain.
A role forcreD, a carbon catabolite repression gene fromAspergillus nidulans, in ubiquitination
Authors: Boase Natasha A. , Kelly Joan M.
Published: July 2004

InAspergillus nidulans, it is known thatcreBencodes a deubiquitinating enzyme that forms a complex with the WD40 motif containing protein encoded bycreC, that mutations in these genes lead to altered carbon source utilization and that thecreD34mutation suppresses the phenotypic effects of mutations increCandcreB. Therefore,creDwas characterized in order to dissect the regulatory network that involves the CreB–CreC deubiquitination complex. CreD contains arrestin domains and PY motifs and is highly similar to the Rod1p and Rog3p proteins fromSaccharomyces cerevisiae. An additional gene was identified in theA. nidulansgenome that also encodes anarrestin andPYmotif‐containing protein, which we have designatedapyA, and thus two similar proteins also exist inA. nidulans. InS. cerevisiae, Rod1p and Rog3p interact with the ubiquitin ligase Rsp5p, and so theA. nidulanshomologue of Rsp5p was identified, and the gene encoding thisHECTubiquitinligase was designatedhulA. CreD and ApyA were tested for protein–protein interactions with HulA via the bacterial two‐hybrid system, and ApyA showed strong interaction, and CreD showed weak interaction, with HulA in this system.
Membrane localization itself but not binding to IICBGlc is directly responsible for the inactivation of the global repressor Mlc in Escherichia coli
Authors: Tanaka Yuya , Itoh Fumie , Kimata Keiko , Aiba Hiroji
Published: July 2004

Mlc is a global transcriptional repressor involved in the regulation of genes linked to glucose metabolism. The activity of Mlc is modulated through the interaction with a major glucose transporter, IICBGlc, in response to external glucose. To understand how IICBGlc–Mlc interaction controls the repressor activity of Mlc, we attempted to isolate Mlc mutants that retain the ability to repress target genes even in the presence of glucose. The Mlc mutants were tested for their ability to interact with IICBGlc. Mutants in which a single amino acid substitution occurs in the N‐terminal portion were no longer able to bind to IICBGlc, suggesting that the N‐terminal region of Mlc is primarily responsible for the interaction with IICBGlc. To examine whether the Mlc–IICBGlc interaction and/or the membrane localization of Mlc per se are essential for the inactivation of Mlc, the properties of several hybrid proteins in which either IIBGlc or Mlc is fused to membrane proteins were analysed. The cytoplasmic IIBGlc domain failed to inhibit the Mlc action although it retains the ability to bind Mlc in cells. However, it gained the ability to inhibit the Mlc activity when it was fused to a membrane protein LacY. In addition, we showed that Mlc is inactivated when fused to membrane proteins but not when fused to cytoplasmic proteins. We conclude that the IICBGlc–Mlc interaction is dispensable for the inactivation of Mlc, and that membrane localization is directly responsible for the inactivation of Mlc.
The Candida albicans CaACE2 gene affects morphogenesis, adherence and virulence
Authors: Kelly Mary T. , MacCallum Donna M. , Clancy Susanne D. , Odds Frank C. , Brown Alistair J. P. , Butler Geraldine
Published: July 2004

Morphogenesis between yeast and hyphal growth is a characteristic associated with virulence in Candida albicans and involves changes in the cell wall. In Saccharomyces cerevisiae, the transcription factor pair Ace2p and Swi5p are key regulators of cell wall metabolism. Here, we have characterized the CaACE2 gene, which encodes the only C. albicans homologue of S. cerevisiae ACE2 and SWI5. Deleting CaACE2 results in a defect in cell separation, increased invasion of solid agar medium and inappropriate pseudohyphal growth, even in the absence of external inducers. The mutant cells have reduced adherence to plastic surfaces and generate biofilms with distinctly different morphology from wild‐type cells. They are also avirulent in a mouse model. Deleting CaACE2 has no effect on expression of the chitinase gene CHT2, but expression of CHT3 and the putative cell wall genes CaDSE1 and CaSCW11 is reduced in both yeast and hyphal forms. The CaAce2 protein is localized to the daughter nucleus of large budded cells at the end of mitosis. C. albicans Ace2p therefore plays a major role in morphogenesis and adherence and resembles S. cerevisiae Ace2p in function.
Transcription of the sporulation gene ssgA is activated by the IclR‐type regulator SsgR in a whi‐independent manner in Streptomyces coelicolor A3(2)
Authors: Traag Bjørn A. , Kelemen Gabriella H. , Van Wezel Gilles P.
Published: July 2004

SsgA plays an important role in the control of sporulation‐specific cell division and morphogenesis of streptomycetes, and ssgA null mutants have a rare conditionally non‐sporulating phenotype. In this paper we show that transcription of ssgA and of the upstream‐located ssgR, an iclR‐type regulatory gene, is developmentally regulated in Streptomyces coelicolor and activated towards the onset of sporulation. A constructed ssgR null mutant was phenotypically very similar to the ssgA mutant. The absence of ssgA transcription in this mutant is probably the sole cause of its sporulation deficiency, as wild‐type levels of sporulation could be restored by the SsgR‐independent expression of ssgA from the ermE promoter. Binding of a truncated version of SsgR to the ssgA promoter region showed that ssgA transcription is directly activated by SsgR; such a dependence of ssgA on SsgR in S. coelicolor is in clear contrast to the situation in S. griseus, where ssgA transcription is activated by A‐factor, and its control by the SsgR orthologue, SsfR, is far less important. Our failure to complement the ssgR mutant with S. griseus ssfR suggests functional differences between the genes. These observations may explain some of the major differences in developmental control between the phylogenetically divergent species S. coelicolor and S. griseus, highlighted in a recent microreview (Chater and Horinouchi (2003) Mol Microbiol 48: 9–15). Surprisingly, transcription of ssgA and ssgR is not dependent on the early whi genes (whiA, whiB, whiG, whiH, whiI and whiJ ).
What functions do linker histones provide?
Authors: Harvey Anne C. , Downs Jessica A.
Published: July 2004

Linker histones have long been known to facilitate chromatin condensation in vitro. For many years, this activity led to speculation that these proteins function as global repressors of transcription. However, work from numerous systems has demonstrated that this is not the case, and that linker histones appear to affect only the transcription of a small subset of genes, and, in fact, act to activate as well as repress transcription. Furthermore, there is evidence that suggests that linker histones are not required for mitotic condensation. In this review, we focus on studies of biological functions of linker histones primarily performed in unicellular eukaryotes. We highlight recent developments pointing towards linker histone involvement in DNA repair and ageing, which raise the possibility that the biological functions of linker histones are more varied than previously imagined.
Rafts and sphingolipid biosynthesis in the kinetoplastid parasitic protozoa
Authors: Denny Paul W. , Smith Deborah F.
Published: July 2004

Although the concept of eukaryotic lipid rafts arouses controversy, recent biophysical studies strongly indicate that inducible, stable and relatively large rafts are a feature of activated mammalian cells. These studies allow us to consider the functional role of lipid rafts in kinetoplastid parasites, which are particularly rich in lipid‐anchored surface molecules. Morphological, biochemical and genetic studies indicate that lipid rafts (and sphingolipid biosythesis) are important in the differentiation of extracellular Leishmania to mammalian‐infective metacyclic promastigotes, perhaps orchestrating the clearly observable reorganization of the plasma membrane during this process that leads to an activated metacyclic primed for invasion. However, the first step in the sphingolipid biosynthetic pathway (mediated by serine palmitoyltransferase), and at least regulated, de novo sphingoid base and ceramide synthesis, are not essential for the pathogenesis of intramacrophage Leishmania amastigotes.