A twisted periscope arrangement for transporting elliptically polarized light without change in its polarization state

The authors describe a dual-mirror 90(∘) twisted periscope arrangement for transporting polarized light in air, wherein a general elliptic polarization state of the light is preserved at all wavelengths. It is experimentally demonstrated that in the wavelength range 400-1000 nm, this arrangement preserves the polarization state fairly well when using either metallic or dielectric mirrors.

Randomised, controlled trial of concomitant pneumococcal and meningococcal conjugate vaccines

A randomised, open-label study compared the immunogenicity and safety of 7-valent pneumococcal conjugate vaccine (PCV7) and meningococcal C conjugate vaccine (MnCC vaccine) administered concomitantly and individually. Infants received PCV7+MnCC vaccine (n=265), PCV7 alone (n=268) or MnCC vaccine alone (n=178). PCV7 was administered at 2, 3½, 6 and 12 months, and MnCC vaccine at 2, 6 and 12 months. For the 7 pneumococcal serotypes tested (4, 6B, 9V, 14, 18C, 19F and 23F), proportions of subjects with pneumococcal serotype-specific immunoglobulin G (IgG) antibody concentrations ≥0.35 μg/mL post-infant series were non-inferior for the PCV7+MnCC vaccine (91.5-99.6%) and PCV7 (89.0-99.6%) groups. Proportions of subjects achieving serogroup C meningococcal serum bactericidal assay titres ≥1:8 post-infant series were non-inferior for the PCV7+MnCC vaccine (99.6%) and MnCC vaccine groups (98.8%). Pneumococcal IgG antibody levels were similar in the PCV7+MnCC vaccine and PCV7 groups at each time point. Post-infant and post-toddler meningococcus C serum bactericidal assay titres and IgG levels were similar in the PCV7+MnCC vaccine and MnCC groups, although pre-toddler, the levels were lower in the PCV7+MnCC vaccine group than the MnCC vaccine group. Immune response rates to diphtheria antigen approached 100% for all vaccine groups. Local reactions were mostly similar among the treatment groups. The MnCC vaccine group had lower rates of some systemic events than the PCV7+MnCC vaccine group. Immune responses to PCV7+MnCC vaccine were non-inferior compared with those seen with each vaccine administered alone.

Fiber optic based system for polarization sensitive spectroscopy of semiconductor quantum structures

We describe an optical fiber based setup for performing polarization resolved magneto-optical spectroscopy measurements under low temperatures ( approximately 4 K) and high magnetic fields ( approximately 8 T). The measurements are performed in a windowless helium Dewar. Circularly polarized light is produced inside the Dewar by inserting the polarizing elements between the fiber end and the sample. Photoconductivity spectra of a GaAs/AlGaAs multiquantum-well sample have been measured over the photon energy range of 1.5-1.7 eV in left and right circularly polarized light under crossed magnetic and electric fields. It is shown that reversing the direction of magnetic field produces the same spectral changes as caused by changing the direction of circular polarization with the optical components.

NMR assignment of actin depolymerizing and dynamics regulatory protein from Leishmania donovani

Leishmania donovani cofilin displays low sequence similarity to other mammalian cofilins and also possesses characteristic activity of its own. Determination of its solution structure would facilitate understanding of the molecular mechanism of actin dynamics regulation in this disease causing pathogen.

Deep gray matter T2 hypointensity is present in patients with clinically isolated syndromes suggestive of multiple sclerosis

Gray matter (GM) magnetic resonance imaging (MRI) T2 hypointensity, a putative marker of iron deposition, is a frequent finding in patients with clinically definite (CD) multiple sclerosis (MS). The objective of this study was to assess: (a) how early deep GM T2 hypointensity occurs in MS, by studying patients with clinically isolated syndromes (CIS) suggestive of MS, and (b) whether they contribute to predict subsequent evolution to CDMS. Dual-echo scans using two different acquisition protocols were acquired from 47 CIS patients and 13 healthy controls (HC). Normalized T2-intensity of the basal ganglia and thalamus was quantified. Patients were assessed clinically at the time of MRI acquisition and after three years. During the observation period, 18 patients (38%) evolved to CDMS. At the baseline, only the GM T2-intensity of the left caudate nucleus was significantly reduced in CIS patients in comparison with the HC (p = 0.04). At the baseline, the T2 intensity of the left caudate nucleus was significantly lower (p = 0.01) in CIS patients with disease dissemination in space (DIS), but not in those without DIS, compared to the HC. The baseline T2 lesion volume, but not GM T2 hypointensity, was associated with evolution to CDMS (hazard ratio = 1.60, 95% confidence interval (CI) = 1.05-2.42; p = 0.02). In CIS patients, deep GM is not spared, suggesting that iron-related changes and neurodegeneration occurs early. The magnitude of such damage is only minor and not associated with an increased risk of evolution to CDMS.

Spinal cord lesions and clinical status in multiple sclerosis: A 1.5 T and 3 T MRI study

OBJECTIVE

Assess the relationship between spinal cord T2 hyperintense lesions and clinical status in multiple sclerosis (MS) with 1.5 and 3 T MRI.

METHODS

Whole cord T2-weighted fast spin-echo MRI was performed in 32 MS patients [Expanded Disability Status Scale (EDSS) score (mean+/-SD: 2+/-1.9), range 0-6.5]. Protocols at 1.5 T and 3 T were optimized and matched on voxel size.

RESULTS

Moderate correlations were found between whole cord lesion volume and EDSS score at 1.5 T (r(s)=.36, p=0.04), but not at 3 T (r(s)=0.13, p=0.46). Pyramidal Functional System Score (FSS) correlated with thoracic T2 lesion number (r(s)=.46, p=0.01) and total spinal cord lesion number (r(s)=0.37, p=0.04) and volume (r(s)=0.37, p=0.04) at 1.5 T. Bowel/bladder FSS correlated with T2 lesion volume and number in the cervical, thoracic, and total spine at 1.5 T (r(s) 0.40-0.57, all p<0.05). These MRI-FSS correlations were non-significant at 3 T. However, these correlation coefficients did not differ significantly between platforms (Choi's test p>0.05). Correlations between whole cord lesion volume and timed 25-foot walk were non-significant at 1.5 T and 3 T (p>0.05). Lesion number and volume did not differ between MRI platforms in the MS group (p>0.05).

CONCLUSIONS

Despite the use of higher field MRI strength, the link between spinal lesions and MS disability remains weak. The 1.5 T and 3 T protocols yielded similar results for many comparisons.

T2 hypointensity in the deep gray matter of patients with benign multiple sclerosis

Background

Gray matter (GM) magnetic resonance imaging (MRI) T2 hypointensity, a putative marker of iron deposition, commonly occurs in multiple sclerosis (MS). However, GM T2 hypointensity in benign MS (BMS) has not yet been characterized.

Objective

To determine the presence of deep GM T2 hypointensity in BMS, compare it to secondary progressive (SP) MS and assess its association with clinical and diffusion tensor (DT) MRI measures.

Methods

Thirty-five cognitively unimpaired BMS, 26 SPMS patients, and 25 healthy controls were analyzed for normalized T2-intensity in the basal ganglia and thalamus, global T2 hyperintense lesion volume, global atrophy, and white matter and GM DT metrics.

Results

BMS and SPMS patients showed deep GM T2 hypointensity compared with controls. T2 hypointensity was similar in both MS subgroups and moderately correlated ( r = −0.45 to 0.42) with DT MRI metrics. GM T2 hypointensity in BMS showed a weak to moderate correlation ( r = −0.44 to −0.35) with disability.

Conclusions

GM in BMS is not spared from structural change including iron deposition. However, while T2 hypointensity is related to global tissue disruption reflected in DT MRI, the expression of benign versus non-benign MS is likely related to other factors.

Rhodotorula mucilaginosa as a cause of persistent femoral nonunion

We present a case of postoperative infection which presented as nonunion fracture femur in a 30-year-old man due to Rhodotorula mucilaginosa. This is the first report of Rhodotorula infection in a patient with fracture nonunion. The patient underwent repeated surgical debridement and received intensive antibiotic therapy before the diagnosis was made. The diagnosis could have been made earlier if the fungal etiology had been suspected earlier. Early suspicion and diagnosis of infection with atypical yeasts could be under-reported because of difficulties in accurate diagnosis and a tendency of attributing isolates to specimen contamination.

Normal findings on brain fluid-attenuated inversion recovery MR images at 3T

BACKGROUND AND PURPOSE

Fluid attenuated inversion recovery (FLAIR) MR imaging of the brain has become a routine tool for assessing lesions in patients with suspected neurologic disorders. There is growing interest in 3T brain FLAIR MR imaging but little normative data are available. The purpose of this study was to evaluate the frequency and topography of cerebral hyperintensities seen with FLAIR MR imaging of the brain at 3T in a normal population and compare those findings to 1.5T.

MATERIALS AND METHODS

Whole-brain 2D FLAIR MR imaging was performed in 22 healthy controls (mean age, 44 +/- 8 years; range, 30-53 years) at 3T. Fifteen of these subjects also underwent 2D FLAIR at 1.5T, with similar optimized parameters and voxel size. Cerebral hyperintense areas, including discrete foci, anterior and posterior periventricular capping, diffuse parenchymal hyperintensity, septal hyperintensity, corticospinal tract hyperintensity, and CSF flow artifacts were assessed. The Spearman rank test assessed the correlation between discrete hyperintense foci and age. The Wilcoxon signed rank test compared foci detectability at 3T versus 1.5T.

RESULTS

FLAIR at 3T commonly showed hyperintensities such as discrete foci (mean, 10.68 per subject; at least 1 present in 68% of subjects), anterior and posterior periventricular capping, diffuse posterior white matter hyperintensity, septal hyperintensity, corticospinal tract hyperintensity, and ventricular CSF flow artifacts. FLAIR at 3T showed a higher hyperintense foci volume (170 +/- 243 versus 93 +/- 152 mm3, P < .01) and number (9.4 +/- 13 versus 5.5 +/- 9.2, P < .01) than at 1.5T. No significant differences (P = .68) in the length/diameter of individual discrete hyperintense foci were seen between 3T and 1.5T. Discrete foci volume (r = 0.72 at 3T, r = 0.70 at 1.5T) and number (r = 0.74 at 3T; r = 0.69 at 1.5T) correlated with age to a similar degree on both platforms. All discrete foci were confined to the noncallosal supratentorial white matter. The other nonfocal hyperintensities (anterior and posterior periventricular capping, diffuse parenchymal hyperintensity, septal hyperintensity, corticospinal tract hyperintensity, and CSF flow artifacts) were generally more common and prominent at 3T than at 1.5T.

CONCLUSIONS

Discrete and diffuse parenchymal brain white matter FLAIR hyperintensities are more common and prominent at 3T than at 1.5T in healthy volunteers.

Deep gray matter involvement on brain MRI scans is associated with clinical progression in multiple sclerosis

BACKGROUND

Conventional brain MRI lesion measures have unreliable associations with clinical progression in multiple sclerosis (MS). Gray matter imaging may improve clinical-MRI correlations.

METHODS

We tested if gray matter MRI measures and conventional measures of lesions/atrophy predicted clinical progression in a 4-year longitudinal study of 97 patients with MS. Baseline and follow-up brain MRI were analyzed for basal ganglia and thalamic normalized T2 signal intensity, whole brain T2-hyperintense lesion volume, and whole brain atrophy. Logistic regression tested the ability of baseline or on-study change in MRI to predict disability progression, as reported by area under the receiver operator characteristics curve (AUC).

RESULTS

Lower caudate T2-intensity at baseline (P= .04; AUC = .69) and on-study decreasing T2-intensity in the putamen (P= .03; AUC = .70) and thalamus (P= .01; AUC = .71) were the MRI variables associated with clinical progression when regression modeling was adjusted for length of follow-up interval, baseline EDSS, disease duration, age, and sex.

CONCLUSIONS

Gray matter T2-hypointensity, suggestive of excessive iron deposition is associated with worsening disability in patients with MS. Gray matter MRI assessment may be able to capture neurodegenerative aspects of the disease, with more clinical relevance than derived from conventional MRI measures. J Neuroimaging 2009;19:3-8.

Cassane diterpenes from Caesalpinia bonduc

Three cassane diterpene hemiketals, caesalpinolide-C, caesalpinolide-D, caesalpinolide-E and one cassane furanoditerpene were isolated from Caesalpinia bonduc. The molecular structures were elucidated using NMR spectroscopy in combination with IR, UV and mass spectral data and relative stereochemistries were determined through ROESY correlation. The isolated compounds were tested for their antiproliferative activity against MCF-7 (breast adenocarcinoma), DU145 (prostate carcinoma), C33A (Cervical carcinoma) and Vero (African green monkey kidney fibroblast) cells.

Predicting clinical progression in multiple sclerosis with the magnetic resonance disease severity scale

BACKGROUND

Individual magnetic resonance imaging (MRI) disease severity measures, such as atrophy or lesions, show weak relationships to clinical status in patients with multiple sclerosis (MS).

OBJECTIVE

To combine MS-MRI measures of disease severity into a composite score.

DESIGN

Retrospective analysis of prospectively collected data.

SETTING

Community-based and referral subspecialty clinic in an academic hospital.

PATIENTS

A total of 103 patients with MS, with a mean (SD) Expanded Disability Status Scale (EDSS) score of 3.3 (2.2), of whom 62 (60.2%) had the relapsing-remitting, 33 (32.0%) the secondary progressive, and 8 (7.8%) the primary progressive form.

MAIN OUTCOME MEASURES

Brain MRI measures included baseline T2 hyperintense (T2LV) and T1 hypointense (T1LV) lesion volume and brain parenchymal fraction (BPF), a marker of global atrophy. The ratio of T1LV to T2LV (T1:T2) assessed lesion severity. A Magnetic Resonance Disease Severity Scale (MRDSS) score, on a continuous scale from 0 to 10, was derived for each patient using T2LV, BPF, and T1:T2.

RESULTS

The MRDSS score averaged 5.1 (SD, 2.6). Baseline MRI and EDSS correlations were moderate for BPF, T1:T2, and MRDSS and weak for T2LV. The MRDSS showed a larger effect size than the individual MRI components in distinguishing patients with the relapsing-remitting form from those with the secondary progressive form. Models containing either T2LV or MRDSS were significantly associated with disability progression during the mean (SD) 3.2 (0.3)-year observation period, when adjusting for baseline EDSS score.

CONCLUSION

Combining brain MRI lesion and atrophy measures can predict MS clinical progression and provides the basis for developing an MRI-based continuous scale as a marker of MS disease severity.

Osteomyelitis variolosa: a report of two cases

We present 2 patients with osteomyelitis variolosa in both elbow joints--sequelae of smallpox. The condyles were elongated and the central portions of the distal humeri were absorbed and the elbow joints were unstable. One of the patients sustained a closed fracture of the distal humerus. The fracture united uneventfully following stabilisation and bone grafting. At the 13-year follow-up, the patient had satisfactory elbow function.