[Genotype and phenotype of female Dravet syndrome with PCDH19 mutations]

OBJECTIVE

To explore the genotype and phenotype of female Dravet syndrome (DS) patients with PCDH19 mutations.

METHOD

Clinical data of all DS patients seen at Pediatric Department of Peking University First Hospital from February 2005 to May 2015 were prospectively collected. Genomic DNAs were extracted from the patients and their family members. Female DS patients without SCN1A mutation were enrolled. PCR and Sanger sequencing were performed to identify PCDH19 mutations. Clinical data of DS patients with PCDH19 mutations were summarized.

RESULT

Five different heterozygous PCDH19 mutations were identified in six unrelated patients of 75 SCN1A-negative female DS patients (8%), among whom five patients had de novo mutations and one patient's mutation was inherited from her affected mother. Three missense mutations and two insertion mutations were all located in exon 1. Mean age of onset of the six patients with PCDH19 mutations was 6.8 months (range 5-9 months). Onset of seizures were triggered by fever in four patients, after vaccination in one and without fever in one. Generalized tonic clonic seizure (GTCS) was the first seizure type in four patients and focal seizure with secondary generalized tonic clonic seizures in the remaining two. During the course, all patients presented multiple seizure types including generalized tonic clonic seizures and focal seizures in all six patients, myoclonic seizures in three, absence seizures and atonic seizures in one respectively. In all patients, seizures manifested fever-sensitive and in clusters. Seizures were always in brief duration, in most less than 5 minutes, except one experienced twice status epilepticus triggered by fever. Six patients had development delay after the seizure onset, two with autism spectrum disorder, three with ataxia.

CONCLUSION

PCDH19 is another important gene of DS after SCN1A, mutations mainly occurred de novo. PCDH19 gene mutation should be routinely screened in female DS patients without SCN1A mutation. The clinical features of female DS patients with PCDH19 mutations include that the main seizures types are generalized tonic clonic seizures and focal seizures, seizures occurr in clusters and fever-sensitive, short seizure duration, rare status epilepticus, common development delay and some may manifest autism spectrum disorders.

[The role of smoking and metabolic enzyme polymorphisms in the organic solvent induced chronic encephalopathy]

OBJECTIVE

The organic solvents and other exogenous compounds of metabolic enzymes genetic variation may affect the risk of the toxic effect of organic solvents exposure. Therefore, this research we observed the glutathione transferase M1 and T1 (GSTM1, GSTT1) deletion mutation genotype, two kinds of microsomal epoxide hydrolase (mEPHX) genetic polymorphism, organic solvents exposure and smoking effection in chronic cases of toxic encephalopathy (CTE) correlation.

METHODS

The object was 115 patients who had a long history of organic solvents exposure, were divieded into two groups: CTE (n=83) , no CET (n=32) according to clinical diagnosis. DNA was isolated from patients in white blood cells through the multiple-polymerase chain reaction to determine the loss of GSTM1 and GSTT1 genotype. two kinds of mEPHX polymorphism were analysised through the PCR-RFLP (restriction fragment length polymorphism).

RESULTS

The relative risk has obviously improved when lack of GSTM1 genotypes to CTE (RR=2.35, 95% CI 2.35 0.96). in according to the patient's Smoking condition and classify genotype, patients lack of GSTM1 genotypes had a significantly higher risk CTE than GSTM1+genotype patients (RR=3.13, 95% CI 3.13 1.2) , both mEPHX polymorphisms had nothing to do with an increased risk of CTE.

CONCLUSION

The GSTM1 genotypes played an important role in the organic solvent induced the CTE of susceptibility.it was Influenced by the interaction between smoking at the same time.

Identifying structural flow defects in disordered solids using machine-learning methods

We use machine-learning methods on local structure to identify flow defects-or particles susceptible to rearrangement-in jammed and glassy systems. We apply this method successfully to two very different systems: a two-dimensional experimental realization of a granular pillar under compression and a Lennard-Jones glass in both two and three dimensions above and below its glass transition temperature. We also identify characteristics of flow defects that differentiate them from the rest of the sample. Our results show it is possible to discern subtle structural features responsible for heterogeneous dynamics observed across a broad range of disordered materials.

Temperature-pressure scaling for air-fluidized grains near jamming

We present experiments on a monolayer of air-fluidized beads in which a jamming transition is approached by increasing pressure, increasing packing fraction, and decreasing kinetic energy. This is accomplished, along with a noninvasive measurement of pressure, by tilting the system and examining behavior versus depth. We construct an equation of state and analyze relaxation time versus effective temperature. By making time and effective temperature dimensionless using factors of pressure, bead size, and bead mass, we obtain a good collapse of the data but to a functional form that differs from that of thermal hard-sphere systems. The relaxation time appears to diverge only as the effective temperature to pressure ratio goes to zero.

Vibrational modes identify soft spots in a sheared disordered packing

We analyze low-frequency vibrational modes in a two-dimensional, zero-temperature, quasistatically sheared model glass to identify a population of structural "soft spots" where particle rearrangements are initiated. The population of spots evolves slowly compared to the interval between particle rearrangements, and the soft spots are structurally different from the rest of the system. Our results suggest that disordered solids flow via localized rearrangements that tend to occur at soft spots, which are analogous to dislocations in crystalline solids.

Aberrant expression of chromogranin A, miR-146a, and miR-146b-5p in prostate structures with focally disrupted basal cell layers: an early sign of invasion and hormone-refractory cancer?

Our recent studies have suggested that prostate tumor invasion is triggered by autoimmunoreactions induced focal basal cell layer disruptions (FBCLD) that selectively favor monoclonal proliferation of the overlying progenitors or of a biologically more aggressive cell clone. As circulating chromogranin-A (CgA) levels are found to correlate with tumor progression and the status of hormone refractoriness, our current study attempted to assess whether CgA-positive cells would be preferentially distributed in epithelial structures with FBCLD. Paraffin-embedded specimens from 50 patients with organ-confined prostate cancer were subjected to double immunohistochemical analysis with monoclonal antibodies to basal cells and CgA. From each case, 3-5 randomly selected fields were digitally photographed and the photos were magnified 400% and the numbers of CgA-positive cells in epithelial structures with non-disrupted, focally disrupted, and lost basal cell layer were separately counted. The averaged number of cell for each category was statistically compared with the Pearson's Chi-square test. In addition, morphologically similar structures with and without CgA-positive cell clusters were microdissected from four selected cases and subjected to a comparison of differential micro-RNA expression levels. Our study revealed that, although isolated CgA-positive cells were seen in both the basal cell layer and the luminal cell population in all cases, only 8 cases (16%) harbored large clusters of CgA-positive cells that were concentrated in a given area, in which all or nearly all cells appeared to share a similar morphological and immunohistochemical profile. Microdissected epithelial structures with CgA-positive cell clusters exhibited a more than 5- and 7-fold lower expression of miR-146a and miR-146b-5p than their CgA-negative counterparts. As focal basal cell layer disruptions and the reduction or loss of miR-146a and miR-146b-5p has been documented to correlate with prostate tumor invasion and hormone refractoriness, our findings suggest that aberrant CgA expression in epithelial structures with FBCLD may represent an early sign of these events.

Statistical mechanics of a gas-fluidized particle

Characterization of the microscopic fluctuations in systems that are far from equilibrium is crucial for understanding the macroscopic response. One approach is to use an 'effective temperature'--such a quantity has been invoked for chaotic fluids, spin glasses, glasses and colloids, as well as non-thermal systems such as flowing granular materials and foams. We therefore ask to what extent the concept of effective temperature is valid. Here we investigate this question experimentally in a simple system consisting of a sphere placed on a fine screen in an upward flow of gas; the sphere rolls because of the turbulence it generates in the gas stream. In contrast to many-particle systems, in which it is difficult to measure and predict fluctuations, our system has no particle-particle interactions and its dynamics can be captured fully by video imaging. Surprisingly, we find that the sphere behaves exactly like a harmonically bound brownian particle. The random driving force and frequency-dependent drag satisfy the fluctuation-dissipation relation, a cornerstone of statistical mechanics. The statistical mechanics of near-equilibrium systems is therefore unexpectedly useful for studying at least some classes of systems that are driven far from equilibrium.

[Expression of glucose transporter-1 in endometrial hyperplasia and well-differentiated endometrioid adenocarcinoma]

OBJECTIVE

To investigate the expression of glucose transporter-1 (GLUT1) in endometrial hyperplasia and well-differentiated endometrioid adenocarcinomas.

METHODS

Sixty formalin fixed, paraffin-embedded sections of various endometrial hyperplasia and well-differentiated endometrioid adenocarcinomas were immunostained with rabbit anti-GLUT1 antibody using streptavidin-biotin method.

RESULTS

Two of 12 simple hyperplasia and one of seven complex hyperplasia without atypia were focally positive in metaplastic epithelia. All complex atypical hyperplasia showed positive in varied degree, and 26 among 28 cases of adenocarcinoma were stained positively.

CONCLUSIONS

Overexpression of GLUT1 is a consistent feature of atypical hyperplasia and adenocarcinoma. GLUT1 immunostaining is found to be helpful in distinguishing hyperplasia with atypia from those without atypia.

Serotyping and antimicrobial susceptibility of group B Streptococcus over an eight-year period in southern Taiwan

The increase in penicillin resistance among pneumococci and viridans streptococci and the development of serotype-specific conjugate vaccine have increased the need for knowledge of the antimicrobial susceptibility and the capsular serotypes of group B streptococci. Over an 8-year period, 351 group B streptococcal isolates from southern Taiwan were tested for antimicrobial susceptibility and serotype determination. Eighty-seven percent of the isolates were typeable. Types III (28.5%) and V (27.1%) were the most common serotypes. The occurrence of type V isolates increased with age, while that of type III isolates decreased with age, showing a predominance in children less than 1 year of age. Of 118 isolates from cases of invasive infection, types Ia, Ib, II, III, IV, and V accounted for 12.7, 11.9, 0.8, 33, 1.7, and 26.3%, respectively. Using the agar dilution method, all isolates were found to be susceptible to penicillin, cefotaxime, and vancomycin, 99.4% to ofloxacin, 78.1% to chloramphenicol, 63.2% to azithromycin, 62.6% to erythromycin, 57.3% to clindamycin, and 2.8% to tetracycline. Chloramphenicol resistance was associated with type III isolates (59 of 100, 59%) and erythromycin and azithromycin resistance with type Ib isolates (25 of 33 176%], and 21 of 33 [64%], respectively). Thus, 72% of the isolates from invasive infections were serotype III, V, or Ia, and penicillin remains the drug of choice for treatment or prophylaxis of group B streptococcal infections in southern Taiwan, despite the high prevalence of penicillin resistance among Streptococcus pneumoniae and viridans streptococci.

Elastically driven linker aggregation between two semiflexible polyelectrolytes

The behavior of mobile linkers connecting two semiflexible charged polymers, such as polyvalent counterions connecting DNA or F-actin chains, is studied theoretically. The chain bending rigidity induces an effective repulsion between linkers at large distances while the interchain electrostatic repulsion leads to an effective short-range interlinker attraction. We find a rounded phase transition from a dilute linker gas where the chains form large loops between linkers to a dense disordered linker fluid connecting parallel chains. The onset of chain pairing occurs within the rounded transition.

Effect of nonzero chain diameter on "DNA" condensation

We present a simple model to investigate the effect of chain diameter on multivalent-counterion-induced attractions between two charged chains. In our minimal model, the chains are rigid rods of diameter D with a uniform charge density on the surface, and the counterions are point ions. As a function of the separation between two rods, we find a repulsive barrier in the free energy whose height increases with D. We have also explored the effect of counterion valency Z on the interaction. For parameters characteristic of DNA, we find that a minimum valency of Z=3 is required to produce condensation. We also find that the shape of the potential is fairly insensitive to Z for Z>/=3. These results are consistent with experimental observations of DNA condensation.

Force Distributions near Jamming and Glass Transitions

We calculate the distribution of interparticle normal forces P(F) near the glass and jamming transitions in model supercooled liquids and foams, respectively. P(F) develops a peak that appears near the glass or jamming transitions, whose height increases with decreasing temperature, decreasing shear stress and increasing packing density. A similar shape of P(F) was observed in experiments on static granular packings. We propose that the appearance of this peak signals the development of a yield stress. The sensitivity of the peak to temperature, shear stress, and density lends credence to the recently proposed generalized jamming phase diagram.

Statistics of shear-induced rearrangements in a two-dimensional model foam

Under steady shear, a foam relaxes stress through intermittent rearrangements of bubbles accompanied by sudden drops in the stored elastic energy. We use a simple model of foam that incorporates both elasticity and dissipation to study the statistics of bubble rearrangements in terms of energy drops, the number of nearest neighbor changes, and the rate of neighbor-switching (T1) events. We do this for a two-dimensional system as a function of system size, shear rate, dissipation mechanism, and gas area fraction. We find that for dry foams, there is a well-defined quasistatic limit at low shear rates where localized rearrangements occur at a constant rate per unit strain, independent of both system size and dissipation mechanism. These results are in good qualitative agreement with experiments on two-dimensional and three-dimensional foams. In contrast, we find for progessively wetter foams that the event size distribution broadens into a power law that is cut off only by system size. This is consistent with criticality at the melting transition.

Effect of ordering on spinodal decomposition of liquid-crystal/polymer mixtures

Partially phase-separated liquid-crystal/polymer dispersions display highly fibrillar domain morphologies that are dramatically different from the typical structures found in isotropic mixtures. To explain this, we numerically explore the coupling between phase ordering and phase-separation kinetics in model two-dimensional fluid mixtures phase separating into a nematic phase, rich in liquid crystal, coexisting with an isotropic phase, rich in polymer. We find that phase ordering can lead to fibrillar networks of the minority polymer-rich phase.

Counterion-mediated, non-pairwise-additive attractions in bundles of like-charged rods

Stiff polyelectrolyte chains, such as DNA, can attract each other in solution even though they have the same sign of charge. The attractions are mediated by multivalent counterions, which lead to an effective interaction at the two-chain level that is attractive at short range and repulsive at long range. However, the effective interchain interactions are not pairwise additive. We present a formulation that allows theoretical treatment of the many-chain problem without assuming pairwise additivity. We show that a bundle of chains held together by counterion-mediated attractions can be described in terms of a bulk and surface free energy, and discuss the temperature dependence of the attraction.

Rickettsia helvetica in Ixodes ricinus ticks in Sweden

In the present study further characterization of the amplified sequence of the citrate synthase gene of the spotted fever group Rickettsia isolated from Ixodes ricinus ticks in Sweden showed that it has 100% homology with the deposited sequence of the citrate synthase gene of Rickettsia helvetica. The restriction fragment length polymorphism (RFLP) pattern of an amplified 382-bp product of the citrate synthase sequence, defined by primers RpCS877 and RpCS1258, yielded fragments for our isolate that could be visualized as a double band that migrated at approximately 44 bp, another double band at 85 bp, and a single band at nearly 120 bp after digestion with the restriction enzyme AluI. When calculating a theoretical PCR-RFLP pattern of the sequence of the citrate synthase gene of R. helvetica from the known positions where the AluI enzyme cuts, we arrived at the same pattern that was obtained for our isolate, a pattern distinctly different from the previously published PCR-RFLP pattern for R. helvetica. Investigation of 125 living I. ricinus ticks showed a higher prevalence of rickettsial DNA in these ticks than we had found in an earlier study. Rickettsial DNA was detected by amplification of the 16S rRNA gene, for which a seminested primer system consisting of two oligonucleotide primer pairs was used. Of the 125 ticks, some were pooled, giving a total of 82 tick samples, of which 20 were found to be positive for the rickettsial DNA gene investigated. When considering the fact that some of the positive samples were pooled, the minimum possible prevalence in these ticks was 20 of 125 (16%) and the maximum possible prevalence was 46 of 125 (36.8%). These prevalence estimates conform to those of other studies of spotted fever group rickettsiae in hard ticks in Europe.

20-[18F]fluoromibolerone, a positron-emitting radiotracer for androgen receptors: synthesis and tissue distribution studies

To develop an androgen receptor-based, positron-emitting imaging agent for prostate tumors, we have prepared 20-fluoromibolerone (F-Mib) and evaluated its tissue distribution. This compound was synthesized in eight steps from 7 alpha-methyl-19-nortestosterone, with fluorine introduced in the penultimate step by fluoride ion displacement on a spirocyclic sulfate. Fluoromibolerone was obtained in 9%-19% radiochemical yield (decay corrected), at 1.5 hr after bombardment, with an effective specific activity of 217-283 Ci/mmol. The relative binding affinity of F-Mib is 53 (versus R1881 = 100 or mibolerone = 118). In tissue distribution studies in diethylstilbestrol-treated male rats, 18F-Mib demonstrates high target/tissue uptake efficiency and selectivity: the prostate uptake at 0.5 hr and 4 hr is 1.0%-1.3% injected dose/gram tissue (ID/g) and 0.5%-0.6% ID/g, respectively; the prostate-to-blood and the prostate-to-muscle (non-target) ratios are both ca. 4 at 0.5 hr, and increase to ca. 12 by 4 hr after injection. The observed distribution of 18F-Mib suggests that it may be useful for in vivo imaging of prostatic tumors in man by positron emission tomography.