Bioartificial Organ Grafts: A View at the Beginning of the Third Millennium

An immunoisolated collection of cells, which communicate and exchange essential factors, co-stimulatory hormones, as well as providing immunoprotection and immunomodulation, can be prepared, given existing scientific and medical know-how, within two decades. These "Bioartificial Organ Grafts" have advantages relative to isolated cell therapies, including beta-cell encapsulation for diabetes treatment, and xenotransplantation, which has a de facto moratorium. This paper documents that the majority of the research for the bioartificial organ grafts has been concluded, with the remaining hurdles minimum in comparison. The use of co-encapsulation and the induction of local immune-privilege will provide a more sensitive humoral hormonal response and graft survival, without systemic immunosuppression. A call for the staged implementation of bioartificial organ grafts, based on the best available medical practice, materials, tissue and technology available, is advocated. The implementation of bioartificial organ grafts can begin within the next two years, based on allografts succeeded by genetically modified human tissue, without the need to pass through a xenograft stage.

Transforming growth factor-beta receptor-3 is associated with pulmonary emphysema

Chronic obstructive pulmonary disease (COPD) is a heterogeneous syndrome, including emphysema and airway disease. Phenotypes defined on the basis of chest computed tomography (CT) may decrease disease heterogeneity and aid in the identification of candidate genes for COPD subtypes. To identify these genes, we performed genome-wide linkage analysis in extended pedigrees from the Boston Early-Onset COPD Study, stratified by emphysema status (defined by chest CT scans) of the probands, followed by genetic association analysis of positional candidate genes. A region on chromosome 1p showed strong evidence of linkage to lung function traits in families of emphysema-predominant probands in the stratified analysis (LOD score = 2.99 in families of emphysema-predominant probands versus 1.98 in all families). Association analysis in 949 individuals from 127 early-onset COPD pedigrees revealed association for COPD-related traits with an intronic single-nucleotide polymorphism (SNP) in transforming growth factor-beta receptor-3 (TGFBR3) (P = 0.005). This SNP was significantly associated with COPD affection status comparing 389 cases from the National Emphysema Treatment Trial to 472 control smokers (P = 0.04), and with FEV(1) (P = 0.004) and CT emphysema (P = 0.05) in 3,117 subjects from the International COPD Genetics Network. Gene-level replication of association with lung function was seen in 427 patients with COPD from the Lung Health Study. In conclusion, stratified linkage analysis followed by association testing identified TGFBR3 (betaglycan) as a potential susceptibility gene for COPD. Published human microarray and murine linkage studies have also demonstrated the importance of TGFBR3 in emphysema and lung function, and our group and others have previously found association of COPD-related traits with TGFB1, a ligand for TGFBR3.

The role of recombinant activated factor VII in cardiac surgery

Recombinant factor VIIa may reduce surgical blood loss and transfusion of blood products in cardiac surgery. However, the true risks of its use in this setting remains to be elucidated, especially when it is administered with other potent pro-haemostatic agents. We reviewed the recent literature on this topic and suggest that the off label use of recombinant factor VIIa is likely to continue. It is our institutional practice to use it in the operating room at a dose of 90 mcg/Kg to ensure there is no obvious correctable surgical source of blood loss, and to be certain that bleeding has stopped before the chest is closed.

Effects of school-based interventions on mental health stigmatization: a systematic review

Stigmatizing, or discriminatory, perspectives and behaviour, which target individuals on the basis of their mental health, are observed in even the youngest school children. We conducted a systematic review of the published and unpublished, scientific literature concerning the benefits and harms of school-based interventions, which were directed at students 18 years of age or younger to prevent or eliminate such stigmatization. Forty relevant studies were identified, yet only a qualitative synthesis was deemed appropriate. Five limitations within the evidence base constituted barriers to drawing conclusive inferences about the effectiveness and harms of school-based interventions: poor reporting quality, a dearth of randomized controlled trial evidence, poor methods quality for all research designs, considerable clinical heterogeneity, and inconsistent or null results. Nevertheless, certain suggestive evidence derived both from within and beyond our evidence base has allowed us to recommend the development, implementation and evaluation of a curriculum, which fosters the development of empathy and, in turn, an orientation toward social inclusion and inclusiveness. These effects may be achieved largely by bringing especially but not exclusively the youngest children into direct, structured contact with an infant, and likely only the oldest children and youth into direct contact with individuals experiencing mental health difficulties. The possible value of using educational activities, materials and contents to enhance hypothesized benefits accruing to direct contact also requires investigation. Overall, the curriculum might serve as primary prevention for some students and as secondary prevention for others.

Computed tomography phenotypes in severe, early-onset chronic obstructive pulmonary disease

Subjects with severe chronic obstructive pulmonary disease (COPD) may have marked differences in emphysema severity on chest computed tomography (CT) scans. Although many patients with severe COPD will have chest CTs performed during their clinical care, chest CTs have not been widely included in epidemiologic and genetic studies of COPD. We sought to determine whether chest CT scans performed for clinical indications can provide useful data in an epidemiologic study of COPD and to determine whether chest CT scans can be used to define subtypes of severe, early-onset COPD. Clinical chest CT scans on 91 probands in the Boston Early-Onset COPD Study were retrospectively reviewed by 2 pulmonologists and 1 to 2 chest radiologists, using a semi-quantitative emphysema severity score, ranging from 0-24. 88 of 91 chest CT scans were suitable for emphysema analysis. There was a wide range of emphysema severity, from mild to severe (1.3-23.7). Emphysema-predominant subjects (upper 3 quartiles of emphysema scores) had more severe airflow obstruction than airway-predominant subjects (lowest quartile of emphysema scores): FEV(1) 17.4% vs. 22.4% predicted, p=0.009. A higher percentage of airway-predominant subjects had a positive bronchodilator response (28.6% vs. 6.7%, p=0.009). Airway-predominant subjects also had a higher frequency of physician-diagnosed asthma (p=0.04) and a trend towards higher serum immunoglobulin E levels (p=0.09). Analysis of siblings of early-onset COPD probands suggested a genetic contribution to the subgroups. Using clinical chest CT scans, we were able to identify an airway-predominant subgroup with asthma-like features among subjects with severe, early-onset COPD.

Interobserver Variability in the Determination of Upper Lobe-Predominant Emphysema

BACKGROUND

Appropriateness for lung volume reduction surgery is often determined based on the results of high-resolution CT (HRCT) scanning of the chest. At many centers, radiologists and pulmonary physicians both review the images, but the agreement between readers from these specialties is not known.

METHODS

Two thoracic radiologists and three pulmonologists retrospectively reviewed the HRCT scans of 30 patients with emphysema involved in two clinical studies at our institution. Each reader assigned an emphysema severity score and assessed upper lobe predominance, using a methodology similar to that of the National Emphysema Treatment Trial. In addition, the percentage of emphysema at -910 Hounsfield units was objectively determined by density mask analysis.

RESULTS

For the emphysema severity scores, (Spearman) correlation between readers ranged from 0.59 (p = 0.0005) to 0.87 (p < 0.0001), with generally stronger correlations among readers from the same medical specialty. Emphysema severity scores were significantly correlated with prebronchodilator and postbronchodilator spirometry findings, as well as with density mask analysis. In the assessment of upper lobe predominance, kappa statistics for agreement ranged from 0.20 (p = 0.4) to 0.60 (p = 0.0008). Examining all possible radiologist-pulmonologist pairs, the two readers agreed in their assessments of emphysema distribution in 75% of the comparisons. Readers agreed on upper lobe-predominant disease in 9 of the 10 patients in which regional density mask analysis clearly showed upper lobe predominance.

CONCLUSIONS

In a group of patients with varying emphysema severity, interobserver agreement in the determination of upper lobe-predominant disease was poor. Agreement between readers tended to be better in cases with clear upper lobe predominance as determined by densitometry.

Transperineal versus hydrogen peroxide-enhanced endoanal ultrasonography in never operated and recurrent cryptogenic fistula-in-ano: a pilot study

BACKGROUND

Accurate delineation of anal fistula anatomy in recurrent cases will assist in surgical fistula eradication whilst preserving continence. Recently, transperineal ultrasonography (TPUS) has been used in perirectal inflammation where there may be advantage over endoanal ultrasonography (EAUS) in complex fistulae- in-ano which lie outside the focal range of the endoanal probe. We assessed the sensitivity of these two imaging modalities to characterize fistula-in-ano, compared to surgical findings.

METHODS

Hand-held 7.5 MHz TPUS was performed in the axial and sagittal planes in never-operated (Group 1, n=10) and recurrent (Group 2, n=10) cryptogenic fistulae where the ultrasonographer was blinded to the initial operative findings. This was compared with hydrogen peroxide-enhanced EAUS using a 7.5 MHz rotating probe, assessing the fistula anatomy, site of the internal opening, confirmation of Goodsall's rule and the presence of secondary tracks, abscess collections and significant horsehoeing of the track.

RESULTS

Overall sensitivity for the detection of trans-sphincteric and extrasphincteric fistulae was 100% using both techniques with a 90% sensitivity for TPUS and an 85% sensitivity for EAUS in the prediction of the internal fistula opening site. The TPUS sensitivity for horseshoeing was poor (28.6%) as was the detection of ancillary abscesses confirmed at surgery (63.6%) but TPUS demonstrated rectovaginal fistulae.

CONCLUSION

TPUS is a novel technique for use in perirectal infection which has a significant learning curve but which is highly accurate for prediction of the anatomy of complex recurrent as well as simple anal fistulae.

High resolution structure of BipD: an invasion protein associated with the type III secretion system of Burkholderia pseudomallei

Burkoldheria pseudomallei is a Gram-negative bacterium that possesses a protein secretion system similar to those found in Salmonella and Shigella. Recent work has indicated that the protein encoded by the BipD gene of B. pseudomallei is an important secreted virulence factor. BipD is similar in sequence to IpaD from Shigella and SipD from Salmonella and is therefore likely to be a translocator protein in the type-III secretion system of B. pseudomallei. The crystal structure of BipD has been solved at a resolution of 2.1 A revealing the detailed tertiary fold of the molecule. The overall structure is appreciably extended and consists of a bundle of antiparallel alpha-helical segments with two small beta-sheet regions. The longest helices of the molecule form a four-helix bundle and most of the remaining secondary structure elements (three helices and two three-stranded beta-sheets) are formed by the region linking the last two helices of the four-helix bundle. The structure suggests that the biologically active form of the molecule may be a dimer formed by contacts involving the C-terminal alpha-helix, which is the most strongly conserved part of the protein. Comparison of the structure of BipD with immunological and other data for IpaD indicates that the C-terminal alpha-helix is also involved in contacts with other proteins that form the translocon.

Crystallization and preliminary X-ray diffraction analysis of BipD, a virulence factor from Burkholderia pseudomallei

Burkholderia pseudomallei, the causative agent of melioidosis, possesses a protein-secretion apparatus that is similar to those found in Salmonella and Shigella. A major function of these secretion systems is to secrete virulence-associated proteins into target cells of the host organism. The BipD gene of B. pseudomallei encodes a secreted virulence factor that is similar in sequence and most likely functionally analogous to IpaD from Shigella and SipD from Salmonella. Thus, the BipD protein is likely to be a component of a type III protein-secretion system (TTSS) in B. pseudomallei. Proteins in the same class as BipD, such as IpaD and SipD, are thought to act as extracellular chaperones to help the hydrophobic translocator proteins enter the target cell membrane, where they form a pore and might even link the translocon pore with the secretion needle. There is evidence that the translocator proteins also bind an integrin which stimulates actin-mediated insertion of the bacterium into the host-cell membrane. Native BipD has been crystallized in a monoclinic crystal form that diffracts X-rays to 2.5 angstroms resolution. BipD protein which incorporates selenomethionine (SeMet-BipD) has also been expressed and forms crystals which diffract to a higher resolution of 2.1 angstroms.

Polarized proton collisions at 205 GeV at RHIC

The Brookhaven Relativistic Heavy Ion Collider (RHIC) has been providing collisions of polarized protons at a beam energy of 100 GeV since 2001. Equipped with two full Siberian snakes in each ring, polarization is preserved during acceleration from injection to 100 GeV. However, the intrinsic spin resonances beyond 100 GeV are about a factor of 2 stronger than those below 100 GeV making it important to examine the impact of these strong intrinsic spin resonances on polarization survival and the tolerance for vertical orbit distortions. Polarized protons were first accelerated to the record energy of 205 GeV in RHIC with a significant polarization measured at top energy in 2005. This Letter presents the results and discusses the sensitivity of the polarization survival to orbit distortions.