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Leucine-rich glioma-inactivated 1-antibody-encephalitis is a treatable and potentially reversible cause of cognitive and psychiatric presentations, and may mimic cognitive decline, rapidly progressive dementia and complex psychosis in older patients. This aetiology is of immediate relevance given the alternative treatment pathway required, compared with other conditions presenting with cognitive deficits.
To model cognitive reserve (CR) longitudinally in a neurodiverse pediatric sample using a residual index approach, and to test the criterion and construct validity of this index.
Method:
Participants were N = 115 children aged 9.5–13 years at baseline (MAge = 10.48 years, SDAge = 0.61), and n = 43 (37.4%) met criteria for ADHD. The CR index represented variance in Matrix Reasoning scores from the WASI that was unexplained by MRI-based brain variables (bilateral hippocampal volumes, total gray matter volumes, and total white matter hypointensity volumes) or demographics (age and sex).
Results:
At baseline, the CR index predicted math computation ability (estimate = 0.50, SE = 0.07, p < .001), and word reading ability (estimate = 0.26, SE = 0.10, p = .012). Longitudinally, change in CR over time was not associated with change in math computation ability (estimate = −0.02, SE = 0.03, p < .513), but did predict change in word reading ability (estimate = 0.10, SE = 0.03, p < .001). Change in CR was also found to moderate the relationship between change in word reading ability and white matter hypointensity volume (estimate = 0.10, SE = 0.05, p = .045).
Conclusions:
Evidence for the criterion validity of this CR index is encouraging, but somewhat mixed, while construct validity was evidenced through interaction between CR, brain, and word reading ability. Future research would benefit from optimization of the CR index through careful selection of brain variables for a pediatric sample.
Diagnosis of latent tuberculosis infection (LTBI) is a concern in haemodialysis (HD) patients. Many studies have compared QuantiFERON-TB Gold In-Tube (QFT-GIT) and tuberculin skin test (TST) for detecting LTBI and reported the κ statistic of agreement between QFT-GIT and TST in HD patients. The present study aimed to systematically review this literature and conduct meta-analysis of individual studies that estimated the κ between QFT-GIT with TST among HD patients. All relevant published studies that were available as full-text were obtained by searching Medline (1950), Web of Sciences (1945), Scopus (1973) through May 2016. The κ was re-estimated from the individual studies and pooled using random effect meta-analysis. Subgroup analysis and meta-regression were applied to evaluate the effect of Bacillus Calmette–Guérin (BCG) vaccination, TST cut-off points, quality of studies, sample size and age on variation of κ estimate. Eight studies involving 901 HD patients were included in meta-analysis. The pooled κ estimate was 0·28 (I2 = 18·4%, P = 0·239, 95% confidence intervals 0·22–0·34). The discordance of TST−/QFT-GIT+ was more than TST+/QFT-GIT−. History of BCG vaccination, TST cut-off points and age are related to variation of κ estimates. TST and QFT-GIT are not comparable in detecting LTBI in HD patients. The higher TST−/QFT-GIT+ ratio compared with TST+/QFT-GIT− ratio, may indicate the superiority of QFT-GIT over TST for detection LTBI in HD patients.
Conversion of CH4 molecule into higher hydrocarbons using two different wavelengths of 248 nm KrF laser and 355 nm of third harmonic of Nd:YAG laser is studied experimentally and theoretically. The stable products are analyzed and the effect of pressure on conversion of methane is measured. The detected reaction products are C2H2, C2H4, and C2H6. The conversion efficiency of 33.5% for 355 nm in comparison to 2.2% conversion for 248 nm for C2H2 is achieved. The potential of laser parameters as an important variable in controlling of final products is investigated.
The optimum convolution of dual short pulse for producing the maximum wakefield and the highest dissociation probability of CH4 has been investigated. By using three fundamental shapes of pulses though four different arrangements, the generated wake are considered in plasma. It is found that when the first and second pulses were rectangular–triangular and sinusoidal pulse shapes, respectively, the resultant wakefield amplitude is the highest. This effect opens up a new novel way by pulse shaping mechanism in the photo dissociation dynamics of molecules and controlling of chemical reactions in the desired channels by short pulse intense lasers for reducing the computation time of genetic algorithm model. Using field assisted dissociation model, the dissociation probability for a CH4+ molecule exposed to a 100 femtosecond 8 Jcm−2 Ti:Sapphire laser pulse is calculated. Here, the highest possible dissociation probability of the methane ion is calculated by the gradient optimization method in which the gradient of a function should be in the direction of the local extremes. The C-H molecular bond of CH4+ ion is assumed to be in the same direction as the electric field component of the laser pulse. These results show that there is an excellent match with experimental data. The remarkable feature of this work is that the sensitivity of the dissociation probability of the initial bond length q, is studied and the desired product channel is controlled by variation of the laser intensity and it's time evolution by introducing a characteristic vectored space for intensity and duration of two tailored rectangular femtosecond laser pulses.
By
David N. Irani, Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA,
Diane E. Griffin, Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
Infections of the central nervous system (CNS) can occur in two anatomically distinct tissue compartments: the subarachnoid and leptomeningeal spaces (meningitis) and the parenchyma of the brain and spinal cord (encephalomyelitis). While an intact blood–brain barrier (BBB) ordinarily deters microorganisms from invading either tissue compartment, it also excludes most circulating components of the immune system, making the CNS susceptible to infection once such invasion does occur. Cells of the immune system can extravasate into the CNS in response to infection, but they appear to do so in a tightly regulated manner. Within the brain, neural cells have restricted immunological function, and the local microenvironment of the CNS can also down-modulate various effector responses of recruited inflammatory cells. In general, a successful host immune response against a CNS infection must overcome these structural and functional barriers to eradicate infectious organisms without causing excessive damage to non-renewable neural cell populations. In some cases, however, the host response is not fully controlled and actually contributes to the neurologic deficits associated with CNS infection. This chapter will review these concepts by citing examples from both human disease states and laboratory-based experimental systems.
Anatomical considerations
There are several anatomical features of the nervous system that influence how local and systemic immune responses are mounted in response to CNS infection. These include: (i) the BBB which stands as a physical barrier against the passage of immune elements from the periphery into the CNS, (ii) the Virchow–Robin spaces immediately surrounding blood vessels that penetrate into the brain where important immunologic reactions can take place, and (iii) cerebrospinal fluid (CSF) recirculation pathways, which may disseminate microorganisms throughout the neuraxis and cause infectious antigens to be carried out of the CNS via particular routes, therefore influencing how they are detected by the immune system in the periphery.
Under normal circumstances, structures that comprise the BBB generally prevent the entry of infectious pathogens, inflammatory cells, and circulating proteins such as antibodies and cytokines into the CNS. Cerebrovascular endothelial cells maintain tight intercellular junctions and very low rates of vesicular transport that differentiate them from the more permeable endothelium found in other tissues. A dense basement membrane ensheathes the cerebrovascular endothelium which is itself surrounded by a network of pericytes and astrocytic foot processes that collectively maintain the integrity of the BBB.
Four case reports of relapsing polychondritis, (RP), are presented, together with a literature review and management suggestions. There are approximately 211 reported cases in world literature making RP an uncommon condition associated with high morbidity and mortality rates. The key to the management of RP is based on accurate and early diagnosis though the ideal medical regimen has yet to be elucidated.