Evaluation of IL12B as a candidate type I diabetes susceptibility gene using data from the Type I Diabetes Genetics Consortium

As part of its efforts to identify genes affecting the risk of type I diabetes (T1D), the Type I Diabetes Genetics Consortium commissioned an extensive survey of variants associated with genes reported earlier to have an association with disease susceptibility. In this report, we present the analysis of a set of single-nucleotide polymorphisms (SNPs) within and flanking the IL12B gene, which encodes the p40 subunit of the cytokines interleukin (IL)-12 and IL-23. No SNP showed individually significant association in the population as a whole. Nevertheless, subjects stratified according to genotype at the earlier reported SNP in the IL12B 3'UTR, rs3212227, confirmed small, but significant, differences in age of disease onset with a relative hazard=0.88 (P=0.005). The protective effect of rs3212227 allele 2 was gender specific (P=0.004 overall and P=0.0003 when unaffected siblings were considered). Among females, the 2.2 genotype was more protective, with relative hazard=0.75. We conclude that while there was no major effect of IL12B polymorphisms on T1D susceptibility in the entire study group, they have an impact on a subset of at-risk individuals.

Collaborative studies to establish the first World Health Organization International Standard for detection of human antibody against human platelet antigen-3a

BACKGROUND AND OBJECTIVES

The platelet-specific antibody anti-human platelet antigen-3a (anti-HPA-3a) is involved in neonatal alloimmune thrombocytopenia, post-transfusion purpura, and platelet refractoriness. However, HPA-3a antibodies are often difficult to detect, probably because the antigen is labile. This report describes the production of a freeze-dried preparation of pooled human plasma, coded 03/190, containing IgG antibodies against the HPA-3a. The material is intended for use as a minimum sensitivity reagent in glycoprotein-specific assays currently used for anti-HPA-3a detection. Laboratories can use it to assess the sensitivity of their 'in-house' assays for anti-HPA-3a and to calibrate local controls for routine use in each batch of tests.

MATERIALS AND METHODS

Plasma containing anti-HPA-3a was obtained from a mother of two babies both born with severe thrombocytopenia, and following dilution it was freeze dried in glass ampoules.

RESULTS

Two collaborative studies demonstrated that the candidate material contained anti-HPA-3a and human leucocyte antigen (HLA) class I antibodies, but no other HPA antibodies that might confuse the detection of the anti-HPA-3a. The minimum dilution that should give a positive result was determined to be 1 : 8 by two further international collaborative studies involving a total of 49 laboratories in 23 countries.

CONCLUSION

The material also contains HLA antibodies and is suitable for use only in techniques that are glycoprotein specific (i.e. monoclonal antibody immobilization of platelet antigens and enzyme-linked immunosorbent assay) where only HPA antibodies will be detected. This standard will allow laboratories to measure their sensitivity of detection of anti-HPA-3a and will also allow those laboratories with relatively insensitive techniques to monitor their performance as they improve their methodology.

Precision and accuracy of low-dose CT protocols in the evaluation of skull landmarks

OBJECTIVES

It was proposed to design a series of low-dose three-dimensional (3D) CT protocols with an effective dose similar to that of the conventional radiographic series (0.011-0.032 mSv) used to assess craniofacial asymmetry. It was then aimed to assess the precision and accuracy for skull landmarks recorded ex vivo using these CT protocols.

METHODS

Four ultra low-dose CT protocols (5 mAs, pitch 1.375/1.75; 10 mAs, pitch 1.375/1.75) were constructed on the basis of published data, dose calculations and measurements. A high-dose CT protocol was used as a reference standard examination. The protocols were used to scan a skull immersed in water. For each protocol, two observers evaluated 17 skull landmarks on two separate occasions. 3D and two-dimensional (2D) accuracy relative to the reference standard examination and inter- and intraobserver precision was calculated.

RESULTS

The 2D accuracy was superior for the 10 mAs protocols and the 10 mAs/1.375 pitch protocol allowed one observer to achieve an accuracy of less than 2 mm for all landmarks. The 2D interrater precision for the 10 mAs/1.375 pitch protocol was superior to the other low-dose protocols and also the high-dose protocol, achieving precision less than 2 mm for 15/17 points. The 10 mAs protocols enabled greater 2D intrarater precision than the 5 mAs protocols for both observers.

CONCLUSIONS

Using the 10 mAs/1.375 pitch CT protocol, it was possible to achieve 2D accuracy of less than 2 mm for almost all skull landmarks with an interrater precision similar to a high-dose CT protocol. Although the estimated effective dose of 0.035 mSv was slightly greater than that of the conventional radiographic series (0.011-0.032 mSv), there was the additional benefit of a 3D data set. The 10 mAs protocols allowed accuracy and precision superior to that of the 5 mAs protocols and hence they are more likely to be clinically applicable.

Diffusive atomistic dynamics of edge dislocations in two dimensions

The fundamental dislocation processes of glide, climb, and annihilation are studied on diffusive time scales within the framework of a continuum field theory, the phase field crystal model. Glide and climb are examined for single edge dislocations subjected to shear and compressive strain, respectively, in a two-dimensional hexagonal lattice. It is shown that the natural features of these processes are reproduced without any explicit consideration of elasticity theory or ad hoc construction of microscopic Peierls potentials. Particular attention is paid to the Peierls barrier for dislocation glide or climb and the ensuing dynamic behavior as functions of strain rate, temperature, and dislocation density. It is shown that the dynamics are accurately described by simple viscous motion equations for an overdamped point mass, where the dislocation mobility is the only adjustable parameter. The critical distance for the annihilation of two edge dislocations as a function of separation angle is also presented.

CT fluoroscopic guided insertion of inferior vena cava filters

The value and use of inferior vena cava (IVC) filters is well documented and has been growing since the first reported filter placement in 1973 and the first percutaneous insertion in 1982. Access routes now include both jugular veins, both ante-cubital veins and both femoral veins. However, all insertions require some form of imaging, usually fluoroscopy, to identify the location of the filter with respect to the IVC and the renal veins. We describe two cases where the patients' weight was significantly greater than the weight limit of the angiography table, necessitating insertion under CT fluoroscopic guidance.

Collaborative study to establish the first international standard for quantitation of anti-HPA-1a

BACKGROUND AND OBJECTIVES

This report describes the production of a freeze-dried preparation of pooled human plasma, containing immunoglobulin G (IgG) antibodies against the human platelet antigen 1a (HPA-1a). The material, coded 03/152, is proposed as an International Standard containing 100 arbitrary units of anti-HPA-1a for use in quantitative assays to determine the anti-HPA-1a activity in clinical samples.

MATERIALS AND METHODS

Plasma samples containing potent anti-HPA-1a were pooled and freeze dried in 1-ml ampoules. In addition, three individual plasma samples were selected which had varying levels of anti-HPA-1a activity. The anti-HPA-1a activity of these three samples was determined by using a variety of quantitative assays with the proposed standard as a reference.

RESULTS

An international collaborative study, which was part of the 2004 ISBT Platelet Immunology Workshop, involved 39 laboratories in 24 countries and showed that the anti-HPA-1a activity in three test samples could be reliably determined by using the proposed standard.

CONCLUSIONS

Laboratories can use this standard to measure the anti-HPA-1a activity in patient's samples. Further studies are required to determine the relationship between anti-HPA-1a activity and clinical outcome in patients with neonatal alloimmune thrombocytopenia (NAIT).

Airway emergency in tuberculosis

We report a case of acute fatal stridor in a patient newly diagnosed with pulmonary tuberculosis and human immunodeficiency virus (HIV) infection. No evidence of direct airway encroachment was identified at autopsy. We review mechanisms by which tuberculosis may cause stridor and discuss the implications of co-existent HIV infection with reference to the recent literature. The report highlights the need for recognition of acute or evolving airway compromise as an uncommon manifestation of tuberculosis.

Proteomic analysis of the cell-surface membrane in chronic lymphocytic leukemia: identification of two novel proteins, BCNP1 and MIG2B

B-cell-specific plasma-membrane proteins are potential targets for either small molecule or antibody-based therapies. We have sought to annotate proteins expressed at the cell surface membrane in patients with chronic lymphocytic leukemia (CLL) using plasma-membrane-based proteomic analysis to identify previously uncharacterized and potentially B-cell-specific proteins. Proteins from plasma-membrane fractions were separated on one-dimensional gels and trypsinized fractions subjected to high-throughput MALDI-TOF mass spectrometry. Using this method, many known B-cell surface antigens were detected, but also known proteins not previously described in this disease or in this cellular compartment, including cell surface receptors, membrane-associated enzymes and secreted proteins, and completely unknown proteins. To validate the method, we show that BLK, a B-cell-specific kinase, is located in the CLL-plasma-membrane fraction. We also describe two novel proteins (MIG2B and B-cell novel protein #1, BCNP1), which are expressed preferentially in B cells. MIG2B is in a highly conserved and defined gene family containing two plasma-membrane-binding ezrin/radixin/moesin domains and a pleckstrin homology domain; the Caenorhabditis elegans homolog (UNC-112) is a membrane-associated protein that colocalizes with integrin at cell-matrix adhesion complexes. BCNP1 is a completely unknown protein with three predicted transmembrane domains, with three alternatively spliced final exons. Proteomic analysis may thus define new potential therapeutic targets.

Mast cell deficient W/W(v) mice lack stress-induced increase in serum IL-6 levels, as well as in peripheral CRH and vascular permeability, a model of rheumatoid arthritis

Corticotropin releasing hormone (CRH) and interleukin-6 (IL-6) are implicated in inflammatory diseases triggered by stress. Acute restraint stress increases serum IL-6 in the blood, but its source is not known. Our current study was carried out in order to determine the contribution of mast cells to stress-induced IL-6 release and to investigate skin CRH and vascular permeability in mice. W/W(v) mast cell deficient and their wild type control +/+ mice were stressed in a plexiglass restraint chamber for 60 or 120 min. Serum corticosterone and IL-6 levels were measured. Other mice were injected with (99)Tchnetium gluceptate ((99)Tc) and its extravastion, indicating vascular permeability, was determined along with CRH levels in the skin and knee joints. Acute stress increased serum IL-6 in mice, but was greatly inhibited in W/W(v) mast cell deficient mice. Vascular permeability to (99)Tc, as well as local CRH levels, were also increased by stress, but not in W/W(v) mice. Findings from our current study suggest a link between mast cells and stress-related skin and joint inflammation and may explain initial events in psoriatic and rheumatoid arthritis.

Extracranial fasciitis in childhood: a sheep in wolf's clothing

Soft tissue tumours in children are rare, and the differentiation between pseudosarcomatous tumours and sarcomas is difficult. Rapidly-enlarging masses within the head and neck region in infants require rapid diagnosis and prompt definitive treatment to lessen psychological burden on the parents and the surgical team. We present a case of a 17-month-old girl who had a large, rapidly-enlarging soft tissue mass within the maxilla which was excised. The diagnosis of childhood extracranial fasciitis was confirmed histopathologically. We emphasise the importance of conservative excision once the diagnosis has been confirmed.

Fibroblast growth factor-18 is a trophic factor for mature chondrocytes and their progenitors

OBJECTIVE

The aim of this study was to examine the effects of recombinant human Fgf18 on chondrocyte proliferation and matrix production in vivo and in vitro. In addition, the expressions of Fgf18 and Fgf receptors (Fgfr) in adult human articular cartilage were examined.

METHODS

Adenovirus-mediated transfer of Fgf18 into murine pinnae and addition of FGF18 to primary cultures of adult articular chondrocytes were used to assess the effects of FGF18 on chondrocytes. In situ hybridization was used to examine the expression of Fgf18 and Fgfr s in adult human articular cartilage.

RESULTS

Expression of Fgf18 by adenovirus-mediated gene transfer in murine pinnae resulted in a significant increase in chondrocyte number. Chondrocytes were identified by staining with toluidine blue and a monoclonal antibody directed against type II collagen. Fgf18, Fgfr 2-(IIIc), Fgfr 3-(IIIc), and Fgfr 4 mRNAs were detected within these cells by in situ hybridization. The nuclei of the chondrocytes stained with antibodies to PCNA and FGF receptor (FGFR) 2. Addition of FGF18 to the culture media of primary articular chondrocytes increased the proliferation of these cells and increased their production of extracellular matrix. To assess the receptor selectivity of FGF18, BaF3 cells stably expressing the genes for the major splice variants of Fgfr1-3 were used. Proliferation of cells expressing Fgfr 3-(IIIc) or Fgfr 2-(IIIc) was increased by incubation with FGF18. Using FGFR-Fc fusion proteins and BaF3 cells expressing Fgfr 3-(IIIc), only FGFR 3-(IIIc)-Fc, FGFR 2-(IIIc)-Fc or FGFR 4-Fc reduced FGF18-mediated cell proliferation. Expression of Fgf18, Fgfr 3-(IIIc) and Fgfr 2-(IIIc) mRNAs was localized to chondrocytes of human articular cartilage by in situ hybridization.

CONCLUSION

These data demonstrate that Fgf18 can act as a trophic factor for elastic chondrocytes and their progenitors in vivo and articular chondrocytes cultured in vitro. Expression of Fgf18 and the genes for two of its receptors in chondrocytes suggests that Fgf18 may play an autocrine role in the biology of normal articular cartilage.

Automated system for simultaneous analysis of delta(13)C, delta(18)O and CO(2) concentrations in small air samples

In this paper we present an automated system for simultaneous measurement of CO(2) concentration, delta(13)C and delta(18)O from small (<1 mL) air samples in a short period of time (approximately 1 hour). This system combines continuous-flow isotope ratio mass spectrometry (CF-IRMS) and gas chromatography (GC) with an inlet system similar to conventional dual-inlet methods permitting several measurement cycles of standard and sample air. Analogous to the dual-inlet method, the precision of this system increases with the number of replicate cycles measured. The standard error of the mean for a measurement with this system is 0.7 ppm for the CO(2) concentration and 0.05 per thousand for the delta(13)C and delta(18)O with four replicate cycles and 0.4 ppm and 0.03 per thousand respectively with nine replicate cycles. The mean offset of our measurements from NOAA/CMDL analyzed air samples was 0.08 ppm for the CO(2) concentration, 0.01 per thousand for delta(13)C and 0.00 per thousand for delta(18)O. A specific list of the parts and operation of the system is detailed as well as some of the applications for micrometeorological and ecophysiological applications.

Vital signs in hospital patients: a systematic review

OBJECTIVES

This review was initiated to identify the best available evidence on vital sign measurements in hospital patients.

METHOD

Inclusion Criteria--Studies that evaluated some aspect of vital signs. Search--Covered all major databases and the references of identified studies. Data Analysis--Because of the nature of identified studies, data were summarised using narrative rather than statistical methods.

RESULTS

A total of 737 papers of which 69 met the inclusion criteria.

CONCLUSION

This review has highlighted a need for further investigation of issues related to the role, nature and optimal practice of monitoring patient vital signs.