Brain bases of recovery following cognitive rehabilitation for traumatic brain injury: a preliminary study

Brain Imaging and Behavior - Many patients with traumatic brain injury (TBI) have persistent cognitive deficits, including decreased attention and working memory. This preliminary study examined...     

Screening of Dihydropyrimidine Dehydrogenase Genetic Variants by Direct Sequencing in Different Ethnic Groups

Dihydropyrimidine dehydrogenase (DPYD) is an enzyme that regulates the rate-limiting step in pyrimidine metabolism, especially catabolism of fluorouracil, a chemotherapeutic agent for cancer. In order to determine the genetic distribution of DPYD, we directly sequenced 288 subjects from five ethnic groups (96 Koreans, 48 Japanese, 48 Han Chinese, 48 African Americans, and 48 European Americans). As a result, 56 polymorphisms were observed, including 6 core polymorphisms and 18 novel polymorphisms. Allele frequencies were nearly the same across the Asian populations, Korean, Han Chinese and Japanese, whereas several SNPs showed different genetic distributions between Asians and other ethnic populations (African American and European American). Additional in silico analysis was performed to predict the function of novel SNPs. One nonsynonymous SNP (+199381A > G, Asn151Asp) was predicted to change its polarity of amino acid (Asn, neutral to Asp, negative). These findings would be valuable for further research, including pharmacogenetic and drug responses studies.     

26‐Year‐Old Man with a Cerebellar Mass

Medulloblastoma accounts for only 1% of all adult CNS tumors. Recently, we have encountered a case of medulloblastoma in a 26 year old man with divergent differentiation including myoblastic, glial, osteoblastic and chondroblastic differentiation. Here we present the results of immunohistochemical staining using several specific antibodies with a discussion and a review of literature.     

The Control of Silica Nanoparticles on the Phase Separation of Poly(methyl methacrylate)/Poly(styrene‐co‐acrylonitrile) Blends

The influence of silica nanoparticles on the lower critical solution temperature (LCST) phase behavior and phase‐separation kinetics of a blend consisting of poly(methyl methacrylate) (PMMA) and poly(styrene‐co‐acrylonitrile) (SAN), is studied via a high‐throughput experimentation (HTE) approach, which combines a composition (φ) and a temperature (T) gradient. The evolution of the phase‐separation process is studied by optical microscopy (OM), small‐angle light scattering (SALS), and transmission electron microscopy (TEM). Depending on the specific interaction between the silica surface and the polymers, the distribution of silica particles during phase separation can be controlled to be either in one of the polymer phases or at the PMMA/SAN interface. The hydrophilic silica nanoparticles preferentially migrate to the PMMA phase, leading to a slow down of the coarsening rate, which may be related to a reduction of the mobility of PMMA due to an increase of the silica concentration. The hydrophobic silica nanoparticles are localized at the PMMA/SAN interface, and the inhibition of coalescence corresponds to the presence of a solid barrier (the nanoparticles) between the polymers, which prevents the coarsening process.

     

Clickable Poly(ethylene glycol)‐Microsphere‐Based Cell Scaffolds

Clickable poly(ethylene glycol) (PEG) derivatives are used with two sequential aqueous two‐phase systems to produce microsphere‐based scaffolds for cell encapsulation. In the first step, sodium sulfate causes phase separation of the clickable PEG precursors and is followed by rapid geleation to form microspheres in the absence of organic solvent or surfactant. The microspheres are washed and then deswollen in dextran solutions in the presence of cells, producing tightly packed scaffolds that can be easily handled while also maintaining porosity. Endothelial cells included during microsphere scaffold formation show high viability. The clickable PEG‐microsphere‐based cell scaffolds open up new avenues for manipulating scaffold architecture as compared with simple bulk hydrogels.

     

Adverse reactions during drug challenges: a single US institution's experience

BackgroundDrug challenge is a useful tool when diagnostic testing lacks predictive value for a questionable history of drug allergy. Placebo-controlled drug challenge studies demonstrate that a significant number of patients report purely subjective symptoms to placebo.ObjectiveTo evaluate the safety and rate of adverse effects when performing drug challenges and to identify predictive factors for occurrences of subjective symptoms during drug challenges.MethodsWe performed a 6-year, retrospective medical record review of patients who underwent drug challenges by members of the Allergy and Immunology Division after consultation deemed drug challenges to be appropriate. Statistical analysis was performed to compare the proportion of patients with subjective symptoms based on certain factors, including sex, age, number of listed drug allergies, interval from historical drug reaction to the drug challenge, and types of historical reaction.ResultsA total of 114 patients underwent 123 drug challenges. Only 1 patient was deemed to have a true positive drug challenge result. Twenty patients reported subjective symptoms during graded challenge, all of which were not deemed a positive challenge. There was a significantly higher proportion of patients who reported subjective symptoms in females, those with a higher number of listed drug allergies, and those whose historical reactions were primarily subjective in nature.ConclusionDrug challenges are safe procedures in appropriately selected patients. A number of patients report subjective symptoms during drug challenges. Identifying patients at high risk for subjective symptoms may assist in determining whether placebo-controlled drug challenges should be performed.