bluuebunny/crossref_metadata_2025_split huggingface dataset:
Relationship between calcium absorption and plasma dehydroepiandrosterone sulphate (DHEAS) in healthy males
Authors: Chen R. Y. T. , Nordin B. E. C. , Need A. G. , Scopacasa F. , Wishart J. , Morris H. A. , Horowitz M. 
Published: April 2008

SummaryContext  Impaired gut sensitivity to 1,25‐dihydroxyvitamin D (1,25(OH)2D), leading to reduced intestinal calcium absorption, has been reported in older men and women. While this phenomenon in postmenopausal women has been attributed to oestrogen deficiency, it is unclear whether the same observation in older men correlates with the age‐related decline in androgen concentrations.Objective  To examine the relationship between androgens and intestinal calcium absorption in older men.Design  Cross‐sectional study on 55 healthy male volunteers, divided into younger (n = 27) and older (n = 28) groups separated according to the median age of 59 years.Main outcome measures  Calcium absorption, total and free (calculated) testosterone, dehydroepiandrosterone sulphate (DHEAS), SHBG, and 1,25(OH)2D, among others, were measured.Results  Calcium absorption, free testosterone and DHEAS, but not 1,25(OH)2D, declined significantly with age. After adjusting for age and body mass index, stepwise regression showed that 1,25(OH)2D and serum albumin were the only significant determinants of calcium absorption in younger men, while the sole determinant in older men was DHEAS, not testosterone. Residual deviations from the regression of calcium absorption on 1,25(OH)2D, reflecting the efficiency of 1,25(OH)2D‐induced calcium absorption, was positively correlated with DHEAS (r = 0·27, P = 0·027).Conclusions  DHEAS is an independent determinant of calcium absorption in older men, although its manner of influence is, as yet, undefined. The age‐related decline of DHEAS may, partly, account for the observed ‘intestinal resistance to 1,25(OH)2D’ in older men.
Clinical manifestations of familial paraganglioma and phaeochromocytomas in succinate dehydrogenase B (SDH‐B) gene mutation carriers
Authors: Srirangalingam Umasuthan , Walker Lisa , Khoo Bernard , MacDonald Fiona , Gardner Daphne , Wilkin Terence J. , Skelly Robert H. , George Emad , Spooner David , Monson John P. , Grossman Ashley B. , Akker Scott A. , Pollard Patrick J. , Plowman Nick , Avril Norbert , Berney Daniel M. , Burrin Jacky M. , Reznek Rodney H. , Kumar V.K. Ajith , Maher Eamonn R. , Chew Shern L. 
Published: April 2008

SummaryObjective  Phaeochromocytomas and paragangliomas are familial in up to 25% of cases and can result from succinate dehydrogenase (SDH) gene mutations. The aim of this study was to describe the clinical manifestations of subjects with SDH‐B gene mutations.Design  Retrospective case‐series.Patients  Thirty‐two subjects with SDH‐B gene mutations followed up between 1975 and 2007. Mean follow‐up of 5·8 years (SD 7·4, range 0–31). Patients seen at St Bartholomew's Hospital, London and other UK centres.Measurements  Features of clinical presentation, genetic mutations, tumour location, catecholamine secretion, clinical course and management.Results  Sixteen of 32 subjects (50%) were affected by disease. Two previously undescribed mutations in the SDH‐B gene were noted. A family history of disease was apparent in only 18% of index subjects. Mean age at diagnosis was 34 years (SD 15·4, range 10–62). 50% of affected subjects had disease by the age of 26 years. 69% (11 of 16) were hypertensive and 80% (12 of 15) had elevated secretions of catecholamines/metabolites. 24% (6 of 25) of tumours were located in the adrenal and 76% (19 of 25) were extra‐adrenal. 19% (3 of 16) had multifocal disease. Metastatic paragangliomas developed in 31% (5 of 16). One subject developed a metastatic type II papillary renal cell carcinoma. The cohort malignancy rate was 19% (6 of 32). Macrovascular disease was noted in two subjects without hypertension.Conclusion  SDH‐B mutation carriers develop disease early and predominantly in extra‐adrenal locations. Disease penetrance is incomplete. Metastatic disease is prominent but levels are less than previously reported. Clinical manifestations may include papillary renal cell carcinoma and macrovascular disease.
Incidence of radiation thyroiditis and thyroid remnant ablation success rates following 1110 MBq (30 mCi) and 3700 MBq (100 mCi) post‐surgical 131I ablation therapy for differentiated thyroid carcinoma
Authors: Cherk Martin H. , Kalff Victor , Yap Kenneth S. K. , Bailey Michael , Topliss Duncan , Kelly Michael J. 
Published: April 2008

SummaryObjective  To evaluate the relationships between thyroid remnant 131I uptake, radiation thyroiditis and remnant ablation success rate between lower (1110 MBq) and higher (3700 MBq) initial ablative 131I dose for post‐surgical ablation therapy for differentiated thyroid cancer.Design  Patients having post‐surgical administration of 1110 MBq (68 patients) or 3700 MBq (115 patients) 131I were retrospectively reviewed. Thyroid remnant 131I uptake on a 48 h post‐administration scan was correlated with neck symptoms experienced. Patients were classified as having insignificant, mild or severe thyroiditis based on symptoms. Absent thyroid bed 131I uptake on a follow‐up 74 MBq 131I study was considered successful ablation.Results  183 patients were included. Median 131I remnant uptake was 37 MBq. 21% (39/183) of patients developed thyroiditis. Incidence and severity of thyroiditis increased with increasing remnant 131I activity (P ≤ 0·0001). Risk of thyroiditis increased by 64% for every 37 MBq increase in remnant 131I uptake. OR = 1·64 [1·36–1·99]. Severe thyoriditis was only seen with remnant 131I uptake > 73 MBq. For patients treated with 1110 MBq and 3700 MBq, incidence of thyroiditis was 12% and 27% (P = 0·02) and remnant ablation success rate was 76% and 84% (P = NS), respectively. Occurrence of thyroiditis did not correlate with successful ablation.Conclusions  Incidence and severity of radiation thyroiditis following 131I remnant ablation therapy is directly related to thyroid remnant 131I uptake. As 1110 MBq 131I is associated with a significantly lower frequency of thyroiditis but similar remnant ablation rate to 3700 MBq, it warrants consideration for thyroid remnant ablation particularly in patients with low risk disease.
Apoptotic cells induce dendritic cell‐mediated suppression via interferon‐γ‐induced IDO
Authors: Williams Charlotte A. , Harry Rachel A. , McLeod Julie D. 
Published: April 2008

SummaryDendritic cells (DC) are sensitive to their local environment and are affected by proximal cell death. This study investigated the modulatory effect of cell death on DC function. Monocyte‐derived DC exposed to apoptotic Jurkat or primary T cells failed to induce phenotypic maturation of the DC and were unable to support CD4+ allogeneic T‐cell proliferation compared with DC exposed to lipopolysaccharide (LPS) or necrotic cells. Apoptotic cells coincubated with LPS‐ or necrotic cell‐induced mature DC significantly suppressed CD80, CD86 and CD83 and attenuated LPS‐induced CD4+ T‐cell proliferation. Reduced levels of interleukin‐12 (IL‐12), IL‐10, IL‐6, tumour necrosis factor‐α and interferon‐γ (IFN‐γ) were found to be concomitant with the suppressive activity of apoptotic cells upon DC. Furthermore, intracellular staining confirmed IFN‐γ expression by DC in association with apoptotic environments. The specific generation of IFN‐γ by DC within apoptotic environments is suggestive of an anti‐inflammatory role by the induction of indoleamine 2,3‐dioxygenase (IDO). Both neutralization of IFN‐γ and IDO blockade demonstrated a role for IFN‐γ and IDO in the suppression of CD4+ T cells. Moreover, we demonstrate that IDO expression within the DC was found to be IFN‐γ‐dependent. Blocking transforming growth factor‐β (TGF‐β) also produced a partial release in T‐cell proliferation. Our study strongly suggests that apoptosis‐induced DC suppression is not an immunological null event and two prime mediators underpinning these functional effects are IFN‐γ‐induced IDO and TGF‐β.
Differential contribution of TAP and tapasin to HLA class I antigen expression
Authors: Belicha‐Villanueva Alan , McEvoy Sarah , Cycon Kelly , Ferrone Soldano , Gollnick Sandra O. , Bangia Naveen 
Published: April 2008

SummaryExpression of class I human leucocyte antigens (HLA) on the surface of malignant cells is critical for their recognition and destruction by cytotoxic T lymphocytes. Surface expression requires assembly and folding of HLA class I molecules in the endoplasmic reticulum with the assistance of proteins such as Transporter associated with Antigen Processing (TAP) and tapasin. Interferon‐γ induces both TAP and tapasin so dissection of which protein contributes more to HLA class I expression has not been possible previously. In this study, we take advantage of a human melanoma cell line in which TAP can be induced, but tapasin cannot. Interferon‐γ increases TAP protein levels dramatically but HLA class I expression at the cell surface does not increase substantially, indicating that a large increase in peptide supply is not sufficient to increase HLA class I expression. On the other hand, transfection of either allelic form of tapasin (R240 or T240) enhances HLA‐B*5001 and HLA‐B*5701 antigen expression considerably with only a modest increase in TAP. Together, these data indicate that in the presence of minimal TAP activity, tapasin can promote substantial HLA class I expression at the cell surface.
Importance of CD80/CD86–CD28 interactions in the recognition of target cells by CD8+CD122+ regulatory T cells
Authors: Shi Zhe , Rifa’i Muhaimin , Lee Young Ho , Shiku Hiroshi , Isobe Ken‐ichi , Suzuki Haruhiko 
Published: April 2008

SummaryCD8+CD122+ regulatory T cells are a newly identified, naturally occurring type of regulatory T cell that produce interleukin‐10 (IL‐10) and effectively suppress interferon‐γ (IFN‐γ) production from both CD8+ and CD4+ target cells. Molecular mechanisms responsible for the recognition of target cells by CD8+CD122+ regulatory T cells were investigated in this study by using an in vitro culture system that reconstitutes the regulatory action of these cells. CD8+CD122+ regulatory T cells did not produce IL‐10 and did not suppress the IFN‐γ production of allogeneic target T cells when they were stimulated by immobilized anti‐CD3 antibody alone, but they clearly produced IL‐10 and suppressed the IFN‐γ production of target cells when stimulated by anti‐CD3 plus anti‐CD28‐coated beads. IFN‐γ production by major histocompatibility complex‐class I‐deficient T cells was also suppressed by CD8+CD122+ regulatory T cells stimulated with anti‐CD3 plus anti‐CD28 antibody but was not suppressed by cells stimulated by anti‐CD3 alone. Experiments examining the blockade of cell surface molecules expressed on either the regulatory cells or the target cells by adding specific neutralizing antibodies in the culture indicated that CD80, CD86, and CD28 molecules were involved in the regulatory action, but cytotoxic T lymphocyte antigen‐4, inducible costimulatory molecule (ICOS) and programmed death‐1 (PD‐1) molecules were not. Finally, CD8+CD122+ cells isolated from CD28‐knockout (CD28−/−) mice showed no regulatory activity. These results indicate that CD8+CD122+ regulatory T cells recognize target T cells via the interaction of CD80/CD86–CD28 molecules to become active regulatory cells that produce suppressive factors such as IL‐10.
CD40 Ligand‐activated, antigen‐specific B cells are comparable to mature dendritic cells in presenting protein antigens and major histocompatibility complex class I‐ and class II‐binding peptides
Authors: Ahmadi Tahamtan , Flies Amanda , Efebera Yvonne , Sherr David H. 
Published: April 2008

SummaryDendritic cells (DC) are increasingly exploited for cell‐based immunotherapy. However, limitations in ex vivo DC growth and DC functional heterogeneity have motivated development of complementary antigen‐presenting cell sources. Here, the ability of CD40 ligand (CD40L)‐activated B cells to fulfil that role was investigated. We demonstrate for the first time that non‐specific or antigen‐specific murine B cells can be grown for extended periods of time by stimulation with CD40L. These cells rapidly up‐regulate and maintain high levels of co‐stimulatory molecules. In a head‐to‐head comparison with DC, CD40L‐expanded B cells were comparable to DC in the presentation of peptides to CD4+ and CD8+ T cells. While DC were superior to antigen non‐specific CD40L‐activated B cells with regard to whole protein (NP‐BSA) processing and presentation, CD40L‐expanded B cells from NP‐BSA‐immunized mice were comparable to DC when presenting BSA or NP‐BSA to primed primary T cells or when presenting NP linked to an unrelated carrier, CGG, to naïve T cells. Thus, the combination of CD40L activation, which supports B‐cell growth and augments intracellular protein processing, and antigen uptake via the B‐cell receptor, allows for efficient uptake, processing, and presentation of whole protein antigens in a fashion comparable to that observed with mature DC. Like DC, CD40L‐activated B cells efficiently home to secondary lymphoid organs in vivo. This system represents a unique tool for studying primary antigen‐specific B cells and the results suggest that the outgrowth of large numbers of highly activated B cells represents a viable and practical complement to DC for cell‐based immunotherapy.
Pulp stones: a review
Authors: Goga R. , Chandler N. P. , Oginni A. O. 
Published: April 2008

AbstractPulp stones are a frequent finding on bitewing and periapical radiographs but receive relatively little attention in textbooks. A review of the literature was therefore performed, initially using the PubMed database and beginning the search with ‘pulp calcifications’ and ‘pulp stones’. Each term provided more than 400 references, many of which related to pulp calcification in general rather than pulp stones, and focussed largely on the problems these changes presented to clinicians. A manual search using references from this source was carried out. Contemporary textbooks in endodontology were also consulted, and an historic perspective gained from a number of older books and references. The factors involved in the development of the pulp stones are largely unknown. Further research may determine the reasons for their formation, but with current endodontic instruments and techniques this is unlikely to alter their relevance to clinicians.
Conventional and surgical endodontic retreatment of a maxillary lateral incisor with unusual anatomy
Authors: Karabucak B. , Ishii H. , Kratchman S. I. 
Published: April 2008

AbstractAim  To describe conventional and surgical endodontic treatment of a maxillary right lateral incisor with an unusual root dilaceration and to discuss the treatment outcome.Summary  Root dilacerations refer to severe curvature or angulations that may occur anywhere along the length of a root. This anatomical deviation may present an unfavourable outcome if clinicians fail to recognize the difficulties. The following case report describes conventional and surgical endodontic treatment of a maxillary right lateral incisor with an unusual root dilaceration.Key learning points

Root morphology may present a challenge for clinicians during root canal treatment.
Clinicians should be aware of the importance of surgical endodontics and be familiar with microsurgery principals and techniques.
Effects of post system and length on the strain and fracture resistance of root filled bovine teeth
Authors: Santos‐Filho P. C. F. , Castro C. G. , Silva G. R. , Campos R. E. , Soares C. J. 
Published: April 2008

AbstractAim  To investigate ex vivo the effects of different post systems and lengths on the strain and fracture resistance of root‐filled teeth.Methodology  One hundred and thirty‐five bovine incisors were sectioned 15 mm from their apices, root‐filled and divided into three groups (n = 45): fibreglass post; prefabricated steel post; cast post and core. Each group was divided into three subgroups (n = 15) according to the post length: 5.0 mm; 7.5 mm; 10.0 mm. All teeth were restored with metal crowns. For strain‐gauge measurement, two strain gauges per sample were used. The fracture resistance (N) was measured and the data were analysed with two‐way analyses of variance, followed by the Tukey’s HSD test (α = 05).Results  For all posts, decreased lengths resulted in increased microstrain values. However, the fibreglass posts were associated with lower increases when compared with cast post and cores and prefabricated steel posts, which showed microstrain values two times higher when the post length was 5.0 mm. The two‐way analyses of fracture resistance values revealed that post length was statistically significant for the metal posts and not significant for the fibreglass post. The fracture mode analysis indicated that all groups tended to demonstrate root fractures in groups restored with metal posts and resin core fractures in groups restored with fibreglass posts.Conclusions  The cast post and core when the length was 10.0 mm had the highest fracture resistance; however, the fibreglass post was effective with the three post lengths, with higher fracture resistance than metal posts when the length was 5.0 mm.
Microbiological evaluation of primary endodontic infections in teeth with and without sinus tract
Authors: Sassone L. M. , Fidel R. , Faveri M. , Fidel S. , Figueiredo L. , Feres M. 
Published: April 2008

AbstractAim  To examine the microbiological status of primary endodontic infections in teeth with and without a sinus tract.Methodology  Samples were collected by means of a size 15 H‐type file and two sterile paper points from 30 cases of primary endodontic infections with (n = 15) or without (n = 15) a sinus tract. The presence of 40 bacterial species was determined by the checkerboard DNA‐DNA hybridization method.Results  The species found at the highest levels and prevalence were Fusobacterium nucleatum sp. vincentii, Porphyromonas gingivalis, Veillonella parvula, Enterococcus faecalis, Campylobacter gracilis and Neisseria mucosa. Total bacterial counts were similar between teeth with (44 × 105) and without (50 × 105) a sinus tract (t‐test: P > 0.05). E. faecalis, Streptococcus anginosus, Capnocytophaga sputigena and Capnocytophaga gingivalis had significantly higher counts in the absence of sinus tract (Mann–Whitney test, P < 0.05). Higher levels of P. gingivalis and Fusobacterium nucleatum sp. nucleatum were observed in cases with a sinus tract. Leptotrichia buccalis (OR = 1.83; CI 95%) and Porphyromonas endodontalis (OR = 2.15; CI 95%) were associated with an increased chance of subjects having a sinus tract.Conclusions  Primary endodontic infections were associated with a large variety of bacterial species. Specific differences between the composition of the microbiota of primary root canal infections were observed in cases with or without a sinus tract.
Spatial and temporal patterns of phenotypic variation in a Neotropical frog
Authors: Robertson J. M. , Robertson A. D. 
Published: April 2008

AbstractAim  Studies of the spatial and temporal patterns of phenotypic diversity help to elucidate the fine‐scale evolutionary and ecological mechanisms underlying geographical differentiation. The red‐eyed tree frog, Agalychnis callidryas, is a widespread Neotropical frog that exhibits a broad range of polymorphism of coloration and flank‐stripe pattern. The goal of this study was two‐fold: first, to investigate the stability of polymorphisms over a 38‐year period; and second, to evaluate biogeographical hypotheses of diversification between lower Central American populations through quantification of phenotypic diversity on a fine geographical scale.Location  This study was conducted at 12 sites across four biogeographical regions in Costa Rica and Panama.Methods  We quantified colour, categorized flank‐stripe pattern from digital photos taken during field sampling, and measured body size for each individual. We compared the regional frequency of each flank‐stripe pattern in 2005 with the frequency distribution from a previous study of the same sites in 1967 using logistic regression analyses. We determined the geographical signal of leg coloration by employing linear discriminant function analyses to generate a classification matrix based on covariance similarities, and by comparison of the average hue values within and between regions.Results  We found a temporal shift in the frequency of flank‐stripe patterns in three of four regions over 38 years. Based on measures of leg coloration, the frequency distribution of flank‐stripe patterns and body size, we conclude that A. callidryas populations are easily distinguishable at a regional scale.Main conclusions  Agalychnis callidryas exhibits regional differentiation in all phenotypic traits measured in this study, supporting the role of three major biogeographical barriers to gene exchange. We found evidence of a putative contact zone between polytypic regions in Costa Rica. In addition, we report temporal instability of the relative frequency of stripe patterns located on the flanks. The ecological and evolutionary mechanisms that may underlie this variation include sexual selection and avoidance of predators.
Post‐glacial range fragmentation is responsible for the current distribution of Potentilla matsumurae Th. Wolf (Rosaceae) in the Japanese archipelago
Authors: Ikeda Hajime , Senni Kei , Fujii Noriyuki , Setoguchi Hiroaki 
Published: April 2008

AbstractAim  We aimed to elucidate how the current geographic distribution of alpine plants in the Japanese archipelago was shaped during Quaternary climatic oscillations, using Potentilla matsumurae as a case study. According to previous phylogeographic studies, post‐glacial range fragmentation (vicariance scenario) and stepwise migration (dispersal scenario) are both possible. We thus aimed to assess which scenario is more probable for the distribution changes of alpine plants in the Japanese archipelago.Location  The alpine zone in the Japanese archipelago.Methods  Using amplified fragment length polymorphism we determined the genotype of 161 individuals of P. matsumurae from 22 populations. Relationships among individuals and populations were examined using principal coordinates analysis and a neighbour‐joining (NJ) tree, respectively. To examine the genetic population structure, we performed analysis of molecular variance (amova) and structure analysis.Results  Differentiation between central Honshu and northern Japan was not very strong based on the principal coordinates analysis among individuals, the NJ tree of populations (59% bootstrap support), or amova (12% of genetic variation). Moreover, structure analysis did not detect clear geographic differentiation across populations. Although the populations in central Honshu were structured geographically (Mantel test: r = 0.45, P < 0.005; NJ tree), those in northern Japan did not exhibit geographic structure regardless of geographic distance (Mantel test: r = 0.26, P = 0.03; NJ tree). Population relationships in the NJ tree did not always reflect the geographic location.Main conclusions  The current geographic structure of P. matsumurae could not be explained by stepwise migration. This suggests that a single continuous distribution during the last glacial period was later fragmented, perhaps by recovering forest, during the post‐glacial period, resulting in the current distribution and phylogeographic structure of P. matsumurae. Our data support the vicariance scenario.