Detection of distortions in images of natural scenes in mild traumatic brain injury patients.

Mild traumatic brain injuries (mTBI) frequently lead to the impairment of visual functions including blurred and/or distorted vision, due to the disruption of visual cortical mechanisms. Previous mTBI studies have focused on specific aspects of visual processing, e.g., stereopsis, using artificial, low-level, stimuli (e.g., Gaussian patches and gratings). In the current study we investigated high-level visual processing by employing images of real world natural scenes as our stimuli. Both an mTBI group and control group composed of healthy observers were tasked with detecting sinusoidal distortions added to the natural scene stimuli as a function of the distorting sinusoid's spatial frequency. It was found that the mTBI group were equally as sensitive to high frequency distortions as the control group. However, sensitivity decreased more rapidly with decreasing distortion frequency in the mTBI group relative to the controls. These data reflect a deficit in the mTBI group to spatially integrate over larger regions of the scene.

Racial differences in intracerebral haemorrhage outcomes in patients with obesity.

OBJECTIVE: This study was conducted to determine the role of obesity and race in intracerebral haemorrhage (ICH) outcomes. METHODS: The Get with the guideline-Stroke database was queried for all admitted patients with spontaneous ICH. Secondary causes of ICH were excluded. Body mass index (BMI) was classified using the Center for Disease Control guidelines. Race was classified as White or non-White. Demographics, clinical, imaging data were retrieved. Outcome measures were hematoma expansion at 24 h and discharge disposition. RESULTS: A total of 428 patients were included in our analysis. Female gender, past history of congestive heart failure, diabetes mellitus, HbA1c, blood pressure, ICH volume, ICH location, intraventricular haemorrhage and hospital length of stay deferred across BMI categories. On multivariate analysis, along with obese categories, age, ICH location and ICH volume were independent predictors of poor outcomes (hematoma expansion and poor discharge disposition). After adjusting for these variables, obesity remained a predictor of poor disposition outcome compared with normal and overweight subjects; Normal vs. Obese OR 0.26 CI 0.115-0.593 p = 0.0014; Obese vs. Overweight OR 3.79 CI 1.68-8.52 p = 0.0013. Nonetheless, obesity did not influence hematoma expansion. Overall, BMI-race classification did not influence outcomes. However, among non-Whites, the obese category had higher odds of a poor disposition outcome than normal (OR 6.84 CI 2.12-22.22 p = 0.0013) or overweight (OR 8.45 CI 2.6-27.49 p = 0.0004) categories. CONCLUSION: An obesity paradox in ICH was not observed in our cohort. In the non-White population, patients with obesity were likely to be associated with poor disposition outcome. Similar findings were not observed in White population.

The genetics of cholesteatoma. A systematic review using narrative synthesis.

OBJECTIVE: A cholesteatoma is a mass of keratinising epithelium in the middle ear. It is a rare disorder that is associated with significant morbidity, and its causative risk factors are poorly understood; on a global scale, up to a million people are affected by this each year. We have conducted a systematic literature review to identify reports about the heritability of cholesteatoma or any constitutional genetic factors that may be associated with its aetiology. DATA SOURCES: A systematic search of MEDLINE (EBSCO) and two databases of curated genetic research (OMIM and Phenopedia) was conducted. STUDY SELECTION: The participants and populations of interest for this review were people treated for cholesteatoma and their family members. The studies of interest reported evidence of heritability for the trait, or any association with congenital syndromes and particular genetic variants. DATA EXTRACTION: The searches identified 449 unique studies, of which 35 were included in the final narrative synthesis. DATA SYNTHESIS: A narrative synthesis was conducted, and data were tabulated to record characteristics, including study design, genetic data and author conclusions. Most of the studies identified in the literature search, and described here, are case reports and so represent the lowest level of evidence. In a few case reports, congenital and acquired cholesteatomas have been shown to segregate within families in the pattern typical of a monogenic or oligogenic disorder with incomplete penetrance. Evidence from syndromic cases could suggest that genes controlling ear morphology may be risk factors for cholesteatoma formation. CONCLUSIONS: This is the first systematic review about the genetics of cholesteatoma, and we have identified a small body of relevant literature that provides evidence of a heritable component for its aetiology. Cholesteatoma is a complex and heterogeneous clinical phenotype, and it is often associated with chronic otitis media and with some rare congenital syndromes known to affect ear morphology and related pathologies.

High-resolution microarray analysis unravels complex Xq28 aberrations in patients and carriers affected by X-linked blue cone monochromacy.

The human X chromosome contains ∼ 1600 genes, about 15% of which have been associated with a specific genetic condition, mainly affecting males. Blue cone monochromacy (BCM) is an X-linked condition caused by a loss-of-function of both the OPN1LW and OPN1MW opsin genes. The cone opsin gene cluster is composed of 2-9 paralogs with 99.8% sequence homology and is susceptible to deletions, duplications, and mutations. Current diagnostic tests employ polymerase chain reaction (PCR)-based technologies; however, alterations remain undetermined in 10% of patients. Furthermore, carrier testing in females is limited or unavailable. High-resolution X chromosome-targeted CGH microarray was applied to test for rearrangements in males with BCM and female carriers from three unrelated families. Pathogenic alterations were revealed in all probands, characterized by sequencing of the breakpoint junctions and quantitative real-time PCR. In two families, we identified a novel founder mutation that consisted of a complex 3-kb deletion that embraced the cis-regulatory locus control region and insertion of an additional aberrant OPN1MW gene. The application of high-resolution X-chromosome microarray in clinical diagnosis brings significant advantages in detection of small aberrations that are beyond the resolution of clinically available aCGH analysis and which can improve molecular diagnosis of the known conditions and unravel previously unrecognized X-linked diseases.

White light conical diffraction.

Conical diffraction occurs when light is incident along the optic axis of a biaxial crystal. The light spreads out into a hollow cone inside the crystal, emerging as a hollow cylinder. The intensity distribution beyond the crystal is described using an adapted paraxial wave dispersion model. We show, experimentally and theoretically, how this results in a transition from conical diffraction for wavelengths at which the crystal is aligned to double refraction for misaligned wavelengths when using a white light source. The radius of the ring and location of the focal image plane (FIP) are also observed to have a wavelength dependency. The evolution of the conically diffracted beam beyond the FIP into the far field is studied and successfully described using a theoretical model.

Colour detection thresholds as a function of chromatic adaptation and light level.

Colour threshold discrimination ellipses were measured for a number of states of chromatic adaptation and a range of luminance levels using the Colour Assessment and Diagnosis (CAD) test. An analysis of these results was carried out by examining the cone excitation signals along the cardinal axes that correspond to detection thresholds in the +L-M (reddish), -L+M (greenish), +S (bluish) and -S (yellowish) colour directions. The results reveal a strong linear relationship between the excitations induced by the adapting background field in each cone class and the corresponding changes needed for threshold detection. These findings suggest that the cone excitation change for threshold detection of colour signals is always the same for a given background excitation level (in any cone class), independent of the excitations generated in the other cone classes. These observations have been used to develop a model to predict colour detection thresholds for any specified background luminance and chromaticity within the range of values investigated in this study (e.g., luminances in the range 0.3 to 31 cd.m(-2) and chromaticities within the gamut of typical CRT displays). Predicted colour thresholds were found to be in close agreement with measured values with errors that do not, in general, exceed the measured within-subject variability.

Outreach obstetrics training in Western Australia improves neonatal outcome and decreases caesarean sections.

The objective of this study was to determine the effect of a multi-professional outreach obstetric training programme on perinatal and neonatal outcomes. This was a retrospective comparison of 5-min low Apgar scores, stillbirth, perinatal death and moderate/severe hypoxic ischaemic encephalopathy rates in 127,753 infants born in Western Australia before and after the introduction of training in rural and remote areas. Following the introduction of the training programme, there was a highly significant (p = 0.003) decrease in the rate of infants born with low 5-min Apgar scores (from 20.4 to 15.4/1,000 live births). While the changes in the other three outcomes were not significant, all three demonstrated a trend for improvement in the intervention area. This is the second study of an educational intervention in obstetrics to demonstrate improvement in neonatal outcome and the first to be associated with a decrease in caesarean sections.

Randomized clinical trial of folate supplementation in patients with peripheral arterial disease.

BACKGROUND: The aim was to determine whether folate supplementation improved arterial function in patients with peripheral arterial disease (PAD). METHODS: Individuals with PAD were randomly assigned to receive 400 microg folic acid (45 patients) or 5-methyltetrahydrofolate (5-MTHF) (48) daily, or placebo (40) for 16 weeks. Primary endpoints were changes in plasma total homocysteine (tHcy), ankle : brachial pressure index (ABPI) and pulse wave velocity (PWV). Secondary outcomes were changes in plasma inflammatory markers. RESULTS: Plasma tHcy was significantly reduced in folic acid and 5-MTHF groups compared with controls: median difference: - 2.12 (95 per cent confidence interval - 3.70 to - 0.75) micromol/l (P = 0.002) and - 2.07 (-3.48 to - 0.54) micromol/l (P = 0.007) respectively. ABPI improved significantly: median difference 0.07 (0.04 to 0.11) (P < 0.001) and 0.05 (0.01 to 0.10) (P = 0.009) respectively. Brachial-knee PWV (bk-PWV) decreased significantly in individuals receiving 5-MTHF and tended to be reduced in those taking folic acid compared with controls: median difference: - 1.10 (-2.20 to - 0.20) m/s (P = 0.011) and - 0.90 (-2.10 to 0.00) m/s (P = 0.051) respectively. Plasma levels of inflammatory markers were not affected. CONCLUSION: Folate administration reduced plasma homocysteine, and slightly improved ABPI and bk-PWV.

Homocysteine and peripheral arterial disease: systematic review and meta-analysis.

OBJECTIVE: To evaluate homocysteine (Hcy) levels in patients with peripheral arterial disease (PAD) as compared to unaffected controls, and to review the clinical effects of therapy aimed at lowering homocysteine in PAD patients. METHODS: MEDLINE, EMBASE and Cochrane databases were searched from 1950 to December 2007. We selected observational studies and trials that evaluated Hcy levels in patients with PAD compared to unaffected controls. We also included trials on the effect of Hcy-lowering therapy (folate supplementation) in PAD patients. Continuous outcomes were pooled in a random effects meta-analysis of the weighted mean difference between comparator groups. RESULTS: We retrieved 33 potentially suitable articles from our search. Meta-analysis of 14 relevant studies showed that Hcy was significantly elevated (pooled mean difference +4.31micromoll; 95% C.I. 1.71, 6.31, p<0.0001 with significant heterogeneity) in patients with PAD compared to controls. As all 14 studies consistently demonstrated raised plasma Hcy levels in PAD patients, the significant heterogeneity in this meta-analysis probably arises from differences in the degree of Hcy elevation. The effect of folate supplementation on PAD was tested in eight clinical trials but clinically important end points were inconsistently reported. CONCLUSION: Patients with PAD have significantly higher Hcy levels than unaffected controls. However, we did not find any robust evidence on clinically beneficial effects of folate supplementation in PAD.

Clinicopathological features and molecular markers of breast cancer in Jos, Nigeria.

BACKGROUND: Several studies have suggested that breast cancer in black women is associated with aggressive features and poor survival. This study examines molecular markers along with clinical stage and pathological grade in breast cancer material from Jos, Nigeria. STUDY DESIGN: The histological diagnoses of 178 consecutive Nigerian patients with breast cancer were retrieved from their hospital records. A subset of 36 patients was staged and their tumours typed and graded. Immunohistochemical staining of sections from paraffin wax embedded tissues from these cases for the expression of oestrogen receptor (ER), progesterone receptor (PGR), Human ERBB2 (or HER2/neu), p53 and cyclin D1 (CCND1) was carried out using the avidin biotin complex (ABC) procedure. RESULTS: A majority of the cases were invasive ductal carcinoma (92.7%), high grade (grade 3, 70.6%) and of late clinical stage (stages III and IV, 58.3%). Only 25% and 27.8% of cases expressed ER and PGR respectively. The ERBB2 and CCND1 antigens were expressed in 25%, and 5.7% of cases respectively. The p53 protein was the most frequently expressed in this study (47.2% of cases). High grade tumours were significantly more likely to be ER and PGR negative (P = 0.006 and P = 0.002 respectively). CONLCLUSION: There is predominance of high grade, invasive ductal carcinomas which are likely to be ER and PGR negative but p53 positive. These features suggest a biologically aggressive form of breast cancer in Nigerian women with the possibility of poor response to both hormonal therapy and chemotherapy.

Precision in transient electric birefringence measurements for colloids.

Electrically induced birefringence is increasingly used as a fast procedure to characterise the size, shape, polarisation and charge parameters of colloids and their interactions. By considering the optical apparatus generally used, attention is drawn to the significant errors that can arise in such experiments if optical component selection and setting are not critically considered.

Scalar interaction limits from the beta-nu correlation of trapped radioactive atoms.

We have set limits on contributions of scalar interactions to nuclear beta decay. A magneto-optical trap provides a localized source of atoms suspended in space, so the low-energy recoiling nuclei can freely escape and be detected in coincidence with the beta. This allows reconstruction of the neutrino momentum, and the measurement of the beta-nu correlation, in a more direct fashion than previously possible. The beta-nu correlation parameter of the 0(+)-->0(+) pure Fermi decay of (38)K(m) is a =0.9981+/-0.0030+0.0032 / -0.0037, consistent with the standard model prediction a =1.

Exoskeleton for forearm pronation and supination rehabilitation.

Loss of function after SCI, ABI or stroke has a marked affect on ones quality of life. Return of function has been a long-standing goal of physical and occupational therapy. Repeated motor practice has been identified as crucial for motor recovery. The development of a robotic device for neuromotor rehabilitation and upper extremity neuromuscular system recovery is described. The actuator mechanism allows free motion when possible, and provides programmable therapeutic levels of resistance. The sensor system allows characterization of the applied forces, and accurate measurement of the range of motion of the joint. The control system provides real time feedback of actuator commands based on sensor data, calibration routines, and operational modes.

HFE mutations in an inflammatory arthritis population.

OBJECTIVES: To determine the value of screening patients with inflammatory arthritis for haemochromatosis-associated mutations in the HFE gene. METHODS: We screened 1000 patients with inflammatory arthritis and 1000 controls for the HFE gene mutations that are associated with haemochromatosis. The arthritis patients were diagnosed between 1989 and 1995 and their blood DNA was archived as part of the Norfolk Arthritis Register project. RESULTS: Five out of 1000 (0.005) patients in the arthritis group were homozygous for the HFE C282Y mutation. This frequency is the same as the frequency of 5/1000 (0.005) for C282Y homozygosity observed in the normal population. It is slightly above the predicted frequency of homozygosity of 0.0044 derived from the gene frequency in the normal population. CONCLUSIONS: These data suggest that most of the C282Y homozygotes occurred in this arthritis group by chance and that their arthritis was incidental to their HFE genotype. This implies that screening for HFE mutations among patients with inflammatory arthritis would infrequently identify patients whose arthritis might benefit from additional treatment.