The placenta in maternal hyperhomocysteinaemia

It is becoming increasingly apparent that mild or moderate hyperhomocysteinaemia may be associated with adverse perinatal complications and outcomes. The placental pathology in 14 pregnancies from 11 women diagnosed retrospectively to have hyperhomocysteinaemia, following a recent history of intrauterine fetal growth restriction, abruption or of thromboembolic disease, were reviewed. Most of the placental findings indicated abnormal placentation but these were not specific to maternal hyperhomocysteinaemia nor found in every placenta. Features observed included absence of trophoblast-induced physiological vascular changes, acute atherosis, intraluminal endovascular trophoblast in the third trimester, infarction, retroplacental haematoma formation and accelerated villous maturity. Uteroplacental vascular thrombosis was also seen. Three of the women had a subsequent pregnancy where they were treated empirically with folic acid, and these resulted in improved perinatal outcomes. The finding of placental pathology warrants investigation of the woman for hyper- homocysteinaemia. Further randomised controlled trials of folic acid supplementation in preventing pregnancy complications associated with hyperhomocysteinaemia should be conducted.     

BOAT: automatic alignment of biomedical ontologies using term informativeness and candidate selection

The biomedical sciences is one of the few domains where ontologies are widely being developed to facilitate information retrieval and knowledge sharing, but there still remains the problem that applications using different ontologies cannot share knowledge without explicit references between overlapping concepts. Ontology alignment is the task of identifying such equivalence relations between concepts across ontologies. Its application to the biomedical domain should address two open issues: (1) determining the equivalence of concept-pairs which have overlapping terms in their names, and (2) the high run-time required to align large ontologies which are typical in the biomedical domain. To address them, we present a novel approach, named the Biomedical Ontologies Alignment Technique (BOAT), which is state-of-the-art in terms of F-measure, precision and speed. A key feature of BOAT is that it considers the informativeness of each component word in the concept labels, which has significant impact on biomedical ontologies, resulting in a 12.2% increase in F-measure. Another important feature of BOAT is that it selects for comparison only concept pairs that show high likelihoods of equivalence, based on the similarity of their annotations. BOAT's F-measure of 0.88 for the alignment of the mouse and human anatomy ontologies is on par with that of another state-of-the-art matcher, AgreementMaker, while taking a shorter time.     

Integrating Health Belief Model and Technology Acceptance Model: An Investigation of Health-Related Internet Use

Background

Today, people use the Internet to satisfy health-related information and communication needs. In Malaysia, Internet use for health management has become increasingly significant due to the increase in the incidence of chronic diseases, in particular among urban women and their desire to stay healthy. Past studies adopted the Technology Acceptance Model (TAM) and Health Belief Model (HBM) independently to explain Internet use for health-related purposes. Although both the TAM and HBM have their own merits, independently they lack the ability to explain the cognition and the related mechanism in which individuals use the Internet for health purposes.

Objective

This study aimed to examine the influence of perceived health risk and health consciousness on health-related Internet use based on the HBM. Drawing on the TAM, it also tested the mediating effects of perceived usefulness of the Internet for health information and attitude toward Internet use for health purposes for the relationship between health-related factors, namely perceived health risk and health consciousness on health-related Internet use.

Methods

Data obtained for the current study were collected using purposive sampling; the sample consisted of women in Malaysia who had Internet access. The partial least squares structural equation modeling method was used to test the research hypotheses developed.

Results

Perceived health risk (β=.135, t ₁₉₉₉=2.676) and health consciousness (β=.447, t ₁₉₉₉=9.168) had a positive influence on health-related Internet use. Moreover, perceived usefulness of the Internet and attitude toward Internet use for health-related purposes partially mediated the influence of health consciousness on health-related Internet use (β=.025, t ₁₉₉₉=3.234), whereas the effect of perceived health risk on health-related Internet use was fully mediated by perceived usefulness of the Internet and attitude (β=.029, t ₁₉₉₉=3.609). These results suggest the central role of perceived usefulness of the Internet and attitude toward Internet use for health purposes for women who were health conscious and who perceived their health to be at risk.

Conclusions

The integrated model proposed and tested in this study shows that the HBM, when combined with the TAM, is able to predict Internet use for health purposes. For women who subjectively evaluate their health as vulnerable to diseases and are concerned about their health, cognition beliefs in and positive affective feelings about the Internet come into play in determining the use of health-related Internet use. Furthermore, this study shows that engaging in health-related Internet use is a proactive behavior rather than a reactive behavior, suggesting that TAM dimensions have a significant mediating role in Internet health management.     

Radiation induced brain injury: assessment of white matter tracts in a pre-clinical animal model using diffusion tensor MR imaging

We aim to study radiation induced white matter injury in a pre-clinical model using Diffusion tensor MR imaging (DTI). Nineteen 12-week old Sprague–Dawley rats were irradiated to the right hemisphere using a linear accelerator. The dose distribution map was coregistered to the DTI map to generate the actual radiation dose to each white matter tract. Rats underwent longitudinal DTI scans at five time points from 4 to 48 weeks post-radiation with histological evaluations. Fractional anisotropy (FA) of the external capsule, fornix, cerebral peduncle, anterior commissure, optic tract and optic nerve was evaluated. Radiation dose was highest at the ipsilateral external capsule and fornix (29.4 ± 1.3 and 29.8 ± 1.1 Gy, respectively). Optic nerve received 50 % dose to the external capsule and other white matter tracts received 80 % dose. Significantly lower FA was firstly found in the ipsilateral external capsule at 4 weeks post-radiation and in the ipsilateral fornix at 40 weeks post-radiation compared to the contralateral side. Significantly lower FA was found in contralateral optic nerve compared to ipsilateral optic nerve at 48 weeks post-radiation despite ipsilateral optic nerves receiving higher radiation dose than contralateral optic nerve (p = 0.021). No differences were found in other white matter regions until 48 weeks. Histology indicated demyelination, axonal degeneration and coagulative necrosis in all injured white matter. DTI can serve as a promising tool for assessment of radiation induced white matter injury and regional radiosensitivity of white matter tracts.     

Activated CD4<Superscript>+</Superscript>T cells enhance radiation effect through the cooperation of interferon-γ and TNF-α

Background  

Approaches that enhance radiation effect may lead to improved clinical outcome and decrease toxicity. Here we investigated whether activated CD4+ T cells (aCD4) can serve as an effective radiosensitizer.     

A new digital optic disc stereo camera: intraobserver and interobserver repeatability of optic disc measurements

AIMS: To investigate the intraobserver and interobserver repeatability of optic disc measurement using a new digital optic disc stereo camera. METHODS: 112 consecutive new patients presenting to a glaucoma service had dilated optic disc photography performed using a new digital stereo camera (Discam, Marcher Enterprises Ltd, Hereford). The images were analysed by two masked observers using a stereo viewer and computer simulated stereopsis. Vertical and horizontal cup:disc ratios (CDR), cup area:disc area, and cup circumference:disc circumference were computed. Intraobserver and interobserver repeatability analyses were performed. Intraclass correlation coefficients (ICC) and 95% tolerance for change (TC) were computed. RESULTS: 220 optic discs were photographed, of which 196 were suitable for analysis (10 were of poor image quality and 14 had anomalous discs). Mean age of patients was 65 years, 60 were male and 48 female. For intraobserver measurements of: horizontal CDR, ICC = 0.94, TC = 0.11 (15% of range); vertical CDR, ICC = 0.92, TC = 0.14 (16% of range); cup area:disc area, ICC = 0.95, TC = 0.10 (13% of range), and cup circumference:disc circumference, ICC = 0.95, TC = 0.09 (14% of range). For interobserver measurements of: horizontal CDR, ICC = 0.89, TC = 0.14 (19% of range); vertical CDR, ICC = 0.90, TC = 0.14 (16% of range); cup area:disc area, ICC = 0.92, TC = 0.13 (16% of range), and cup circumference:disc circumference, ICC = 0.90, TC = 0.12 (17% of range). Systematic bias between observers was within acceptable limits. CONCLUSIONS: Digital stereo disc photography and analysis provide repeatable measures of optic disc variables. The results compare favourably with ophthalmoscopic and stereophotographic methods of assessment of the optic disc.     

Malignant fibrous histiocytoma of the eyelid: differential diagnosis and management

PURPOSE: Malignant fibrous histiocytoma (MFH) is a pleomorphic soft tissue sarcoma that occurs rarely in the periocular region. The purpose of this study was to present a case series of periocular MFH and to discuss the differential diagnosis and management. METHODS: This is a retrospective case review of patients diagnosed with periocular MFH from tertiary hospitals and private practices. RESULTS: Four patients, two women and two men with periocular MFH, had a mean age of 81 years (range, 72 to 85 years). All tumors were <5 cm in diameter and of storiform pleomorphic histologic subtype. One was located deep and 3 presented superficially. The initial diagnoses were sarcomatoid carcinoma, atypical fibroxanthoma, and leiomyosarcoma that were subsequently reclassified as MFH. One patient had a frozen section, 1 had fast track paraffin section margin control, and 2 had no frozen section margins at the initial excisions. Histology showed 2 negative margins, 1 close margin, and 1 positive margin that were cleared with wide local excision. Local recurrence occurred in 3 cases, and of these, 1 required orbital exenteration. Adjuvant radiotherapy was given to 3 patients. One had regional node metastases. There were no distant metastases or tumor-related deaths. Mean follow-up period was 36 +/- 35 months (median, 30; range, 1 to 84 months). CONCLUSIONS: This study highlights the difficulties in the clinicopathologic diagnosis of periocular MFH and in particular the distinction of more superficial tumors from atypical fibroxanthoma. The mainstay of treatment is complete surgical excision with wide margins, and consideration should be given to histologic margin control in addition to adjuvant radiotherapy.