Automated ventricular mapping with multi-atlas fluid image alignment reveals genetic effects in Alzheimer's disease

We developed and validated a new method to create automated 3D parametric surface models of the lateral ventricles in brain MRI scans, providing an efficient approach to monitor degenerative disease in clinical studies and drug trials. First, we used a set of parameterized surfaces to represent the ventricles in four subjects' manually labeled brain MRI scans (atlases). We fluidly registered each atlas and mesh model to MRIs from 17 Alzheimer's disease (AD) patients and 13 age- and gender-matched healthy elderly control subjects, and 18 asymptomatic ApoE4-carriers and 18 age- and gender-matched non-carriers. We examined genotyped healthy subjects with the goal of detecting subtle effects of a gene that confers heightened risk for Alzheimer's disease. We averaged the meshes extracted for each 3D MR data set, and combined the automated segmentations with a radial mapping approach to localize ventricular shape differences in patients. Validation experiments comparing automated and expert manual segmentations showed that (1) the Hausdorff labeling error rapidly decreased, and (2) the power to detect disease- and gene-related alterations improved, as the number of atlases, N, was increased from 1 to 9. In surface-based statistical maps, we detected more widespread and intense anatomical deficits as we increased the number of atlases. We formulated a statistical stopping criterion to determine the optimal number of atlases to use. Healthy ApoE4-carriers and those with AD showed local ventricular abnormalities. This high-throughput method for morphometric studies further motivates the combination of genetic and neuroimaging strategies in predicting AD progression and treatment response.     

New Canadian natural health product regulations: a qualitative study of how CAM practitioners perceive they will be impacted

Background  

New Canadian policy to regulate natural health products (NHPs), such as herbs and vitamins were implemented on January 1^st, 2004. We explored complementary and alternative medicine (CAM) practitioners' perceptions of how the new regulations may affect their practices and relationships with patients/consumers.     

Olfactomotor activity during imagery mimics that during perception

Neural representations created in the absence of external sensory stimuli are referred to as imagery, and such representations may be augmented by reenactment of sensorimotor processes. We measured nasal airflow in human subjects while they imagined sights, sounds and smells, and only during olfactory imagery did subjects spontaneously enact the motor component of olfaction--that is, they sniffed. Moreover, as in perception, imagery of pleasant odors involved larger sniffs than imagery of unpleasant odors, suggesting that the act of sniffing has a functional role in creating of olfactory percepts.     

Galactose residues on the lipooligosaccharide of Moraxella catarrhalis 26404 form the epitope recognized by the bactericidal antiserum from conjugate vaccination

Lipooligosaccharide (LOS) from Moraxella catarrhalis has the potential to elicit bactericidal antibodies against the pathogen. We generated LOS-based conjugate vaccines that elicited bactericidal antibodies in animal models. However, epitopes on the LOS recognized by the functional anti-LOS antibodies remain unidentified. In this study, a mutant strain, D4, which lost the recognition by a bactericidal anti-LOS rabbit serum in Western blotting was generated from a serotype C strain 26404 by random transposon mutagenesis. Sequence analysis revealed there was an insertion of a kanamycin resistance gene in the lgt2 gene of D4, which encodes beta(1-4)-galactosyltransferase. An isogenic lgt2 mutant, 26404lgt2, was constructed. Structural analysis indicated that the mutant strain produced a truncated LOS lacking terminal galactoses from 4- and 6-linked oligosaccharide chains of strain 26404. Further studies showed that the antiserum lost the recognition of both mutant cells and LOSs in Western blotting, an enzyme-linked immunosorbent assay (ELISA), or a flow cytometry assay. The antiserum also lost the ability to kill the mutant strain in a bactericidal assay, whereas it showed a bactericidal titer of 1:80 to strain 26404. In an inhibition ELISA, d-(+)-galactose or 26404lgt2 LOS showed no inhibition. However, the 26404 LOS and a serotype A O35E LOS with terminal galactoses on its 6-linked oligosaccharide chain showed >90% inhibition, while a serotype B 26397 LOS showed >60% inhibition. These studies suggest that the terminal alpha-Gal-(1-->4)-beta-Gal on the 6-linked oligosaccharide chain of 26404 LOS plays a critical role in forming the epitope recognized by the bactericidal antiserum induced by immunization with our conjugate vaccine.     

Attitudes to specialist palliative care and advance care planning in people with COPD: a multi-national survey of palliative and respiratory medicine specialists

Background

Chronic obstructive pulmonary disease (COPD) guidelines recommend early access to palliative care together with optimal, disease-directed therapy for people with advanced disease, however, this occurs infrequently. This study explored the approaches of respiratory and palliative medicine specialists to palliative care and advance care planning (ACP) in advanced COPD.

Methods

An online survey was emailed to all specialists and trainees in respiratory medicine in Australia and New Zealand (ANZ), and to all palliative medicine specialists and trainees in ANZ and the United Kingdom.

Results

Five hundred seventy-seven (33.1%) responses were received, with 440 (25.2%) complete questionnaires included from 177 respiratory and 263 palliative medicine doctors. Most respiratory doctors (140, 80.9%) were very or quite comfortable providing a palliative approach themselves to people with COPD. 113 (63.8%) respiratory doctors recommended referring people with advanced COPD to specialist palliative care, mainly for access to: psychosocial and spiritual care (105, 59.3%), carer support (104, 58.5%), and end-of-life care (94, 53.1%). 432 (98.2%) participants recommended initiating ACP discussions. Palliative medicine doctors were more likely to recommend discussing: what palliative care is (p <?0.0001), what death and dying might be like (p?<?0.0001) and prognosis (p =?0.004). Themes highlighted in open responses included: inadequate, fragmented models of care, with limited collaboration or support from palliative care services.

Conclusions

While both specialties recognised the significant palliative care and ACP needs of people with advanced COPD, in reality few patients access these elements of care. Formal collaboration and bi-directional support between respiratory and palliative medicine, are required to address these unmet needs.

     

Development and maturation of the fibrous components of the arterial roots in the mouse heart

The arterial roots are important transitional regions of the heart, connecting the intrapericardial components of the aortic and pulmonary trunks with their ventricular outlets. They house the arterial (semilunar) valves and, in the case of the aorta, are the points of coronary arterial attachment. Moreover, because of the semilunar attachments of the valve leaflets, the arterial roots span the anatomic ventriculo‐arterial junction. By virtue of this arrangement, the interleaflet triangles, despite being fibrous, are found on the ventricular aspect of the root and located within the left ventricular cavity. Malformations and diseases of the aortic root are common and serious. Despite the mouse being the animal model of choice for studying cardiac development, few studies have examined the structure of their arterial roots. As a consequence, our understanding of their formation and maturation is incomplete. We set out to clarify the anatomical and histological features of the mouse arterial roots, particularly focusing on their walls and the points of attachment of the valve leaflets. We then sought to determine the embryonic lineage relationships between these tissues, as a forerunner to understanding how they form and mature over time. Using histological stains and immunohistochemistry, we show that the walls of the mouse arterial roots show a gradual transition, with smooth muscle cells (SMC) forming the bulk of wall at the most distal points of attachments of the valve leaflets, while being entirely fibrous at their base. Although the interleaflet triangles lie within the ventricular chambers, we show that they are histologically indistinguishable from the arterial sinus walls until the end of gestation. Differences become apparent after birth, and are only completed by postnatal day 21. Using Cre‐lox‐based lineage tracing technology to label progenitor populations, we show that the SMC and fibrous tissue within the walls of the mature arterial roots share a common origin from the second heart field (SHF) and exclude trans‐differentiation of myocardium as a source for the interleaflet triangle fibrous tissues. Moreover, we show that the attachment points of the leaflets to the walls, like the leaflets themselves, are derived from the outflow cushions, having contributions from both SHF‐derived endothelial cells and neural crest cells. Our data thus show that the arterial roots in the mouse heart are similar to the features described in the human heart. They provide a framework for understanding complex lesions and diseases affecting the aortic root.     

The locomotor system of the ocean sunfish Mola mola (L.): role of gelatinous exoskeleton,horizontal septum,muscles and tendons

Adult ocean sunfish are the heaviest living teleosts. They have no axial musculature or caudal fin. Propulsion is by unpaired dorsal and anal fins; a pseudocaudal fin (‘clavus’) acts as a rudder. Despite common perception, young sunfish are active predators that swim quickly, beating their vertical fins in unison to generate lift‐based propulsion and attain cruising speeds similar to salmon and marlin. Here we show that the thick subcutaneous layer (or ‘capsule’), already known to provide positive buoyancy, is also crucial to locomotion. It provides two compartments, one for dorsal fin musculature and one for anal fin muscles, separated by a thick, fibrous, elastic horizontal septum that is bound to the capsule itself, the roof of the skull and the dorsal surface of the short vertebral column. The compartments are braced sagittally by bony haemal and neural spines. Both fins are powered by white muscles distributed laterally and red muscles located medially. The anal fin muscles are mostly aligned dorso‐ventrally and have origins on the septum and haemal spines. Dorsal fin muscles vary in orientation; many have origins on the capsule above the skull and run near‐horizontally and some bipennate muscles have origins on both capsule and septum. Such bipennate muscle arrangements have not been described previously in fishes. Fin muscles have hinged tendons that pass through capsular channels and radial cartilages to insertions on fin rays. The capsule is gelatinous (89.8% water) with a collagen and elastin meshwork. Greasy in texture, calculations indicate capsular buoyancy is partly provided by lipid. Capsule, septum and tendons provide elastic structures likely to enhance muscle action and support fast cruising.     

Risk factors for very preterm delivery and delivery of very-small-for-gestational-age infants among HIV-exposed and HIV-unexposed infants in Botswana

Objective

To evaluate risk factors for very preterm delivery (VPTD) and very-small-for-gestational-age (VSGA) births in a country with a high HIV prevalence.

Methods

Obstetric records at 6 hospitals across Botswana were reviewed at delivery; VPTD was defined as birth before 32 weeks of pregnancy and VSGA as birth weight below the 3rd percentile for Botswana-specific norms.

Results

Of 16 219 live births born after 26 weeks of pregnancy, 701 (4.3%) were delivered very preterm and 607 (3.7%) were VSGA; 4347 (28.4%) were documented as HIV-exposed. In a multivariable analysis, HIV infection and hypertension during pregnancy were associated with a VPTD (adjusted odds ratio [AOR]: HIV 1.65, hypertension 1.75) and a VSGA birth (AOR: HIV infection 1.90, hypertension 3.44). Among HIV-infected women, the continuation of highly active antiretroviral therapy (HAART) from before conception was associated with a VSGA birth (AOR 1.75) but not with a VPTD (AOR 0.78). In a secondary analysis, HAART continuation was associated with hypertension during pregnancy (AOR 1.34).

Conclusion

Hypertension and HIV infection were risk factors for a VPTD and a VSGA birth. Continuation of HAART from before conception was associated with a VSGA birth but not with a VPTD.     

Internal Iliac Artery Balloon Tamponade in Placenta Accreta: Outcomes From the Largest Tertiary Accreta Referral Centre in British Columbia

Objective

Placenta accreta syndromes are well-recognized risk factors for severe postpartum hemorrhage and are associated with significant maternal morbidity. Internal iliac artery balloon tamponade is an adjunctive procedure used to reduce blood loss at the time of Caesarean hysterectomy with variable results in the reported literature. This study investigated the outcomes of preoperative balloon tamponade at the largest tertiary referral centre for placenta accreta in British Columbia.