Femtosecond laser fabrication of monolithic double volume phase-gratings in glass.

A diffractive optical element was fabricated by monolithically integrating two volume phase-gratings (VPGs) in the bulk of a single-piece transparent material. A computer model of the diffraction generated by the double volume phase-grating (DVPG) was made with a rigorous coupled wave analysis simulator. Simulations and experiments show that the diffractive behavior of a DVPG can be controlled by arranging the relative displacement and the distance between the VPGs according to Talbot self-imaging planes. In order to diffract the total incident light, the phase accumulation in the VPGs has to be π/2, which was achieved by single-scan femtosecond laser processing of a nanocrystal doped glass as the substrate material. Ex situ microscope images of the cross-sections are presented for laser processed lines in the form of VPGs and DVPGs. The far-field diffraction of DVPGs formed by selectively located VPGs was characterized with a monochromatic 633 nm and a supercontinuum white light. Functional designs of high diffraction efficiency with potential applications in photonics were successfully fabricated in a one-step and free of chemicals process.

Structure and function of neonatal social communication in a genetic mouse model of autism.

A critical step toward understanding autism spectrum disorder (ASD) is to identify both genetic and environmental risk factors. A number of rare copy number variants (CNVs) have emerged as robust genetic risk factors for ASD, but not all CNV carriers exhibit ASD and the severity of ASD symptoms varies among CNV carriers. Although evidence exists that various environmental factors modulate symptomatic severity, the precise mechanisms by which these factors determine the ultimate severity of ASD are still poorly understood. Here, using a mouse heterozygous for Tbx1 (a gene encoded in 22q11.2 CNV), we demonstrate that a genetically triggered neonatal phenotype in vocalization generates a negative environmental loop in pup-mother social communication. Wild-type pups used individually diverse sequences of simple and complicated call types, but heterozygous pups used individually invariable call sequences with less complicated call types. When played back, representative wild-type call sequences elicited maternal approach, but heterozygous call sequences were ineffective. When the representative wild-type call sequences were randomized, they were ineffective in eliciting vigorous maternal approach behavior. These data demonstrate that an ASD risk gene alters the neonatal call sequence of its carriers and this pup phenotype in turn diminishes maternal care through atypical social communication. Thus, an ASD risk gene induces, through atypical neonatal call sequences, less than optimal maternal care as a negative neonatal environmental factor.

Prematurity: A medical history of obligatory consideration when assessing the retinal ganglion cell complex.

INTRODUCTION: Premature children birth and survival is becoming more frequent due to the improvement in obstetric and neonatal care. This makes it increasingly common to find patients with history of preterm birth in ophthalmology clinics, both in pediatric and adult ages. Premature birth can lead to ocular structural changes, being possible to affect the ganglion cell complex (GCC), among other structures, which can be studied using optical coherence tomography. MATERIALS AND METHODS: To carry out a bibliographic review of the studies that analyze GCC in patients with a history of prematurity compared with patients born at term. RESULTS: Several studies that analyze GCC in patients with a history of prematurity are referenced and their results are studied. CONCLUSIONS: In our clinical practice, knowing the history of prematurity is fundamental in the assessment of GCC measured by optical coherence tomography, since this layer is different in the patients with a history of prematurity compared to patients born at term.

Effect of Stimulus-Dependent Spike Timing on Population Coding of Sound Location in the Owl's Auditory Midbrain.

In the auditory system, the spectrotemporal structure of acoustic signals determines the temporal pattern of spikes. Here, we investigated this effect in neurons of the barn owl's auditory midbrain (Tyto furcata) that are selective for auditory space and whether it can influence the coding of sound direction. We found that in the nucleus where neurons first become selective to combinations of sound localization cues, reproducibility of spike trains across repeated trials of identical sounds, a metric of across-trial temporal fidelity of spiking patterns evoked by a stimulus, was maximal at the sound direction that elicited the highest firing rate. We then tested the hypothesis that this stimulus-dependent patterning resulted in rate co-modulation of cells with similar frequency and spatial selectivity, driving stimulus-dependent synchrony of population responses. Tetrodes were used to simultaneously record multiple nearby units in the optic tectum (OT), where auditory space is topographically represented. While spiking of neurons in OT showed lower reproducibility across trials compared with upstream nuclei, spike-time synchrony between nearby OT neurons was highest for sounds at their preferred direction. A model of the midbrain circuit explained the relationship between stimulus-dependent reproducibility and synchrony, and demonstrated that this effect can improve the decoding of sound location from the OT output. Thus, stimulus-dependent spiking patterns in the auditory midbrain can have an effect on spatial coding. This study reports a functional connection between spike patterning elicited by spectrotemporal features of a sound and the coding of its location.

Rebound after discontinuation of teriflunomide in patients with multiple sclerosis: 2 case reports.

Teriflunomide is an oral first-line disease modifying treatment (DMT) for patients with relapsing-remitting multiple sclerosis (RRMS). It can take up to two years to achieve systemic clearance of teriflunomide to an acceptable level, but this washout period may be accelerated by administration of cholestyramine. Relapse of multiple sclerosis (MS) during washout of teriflunomide or other first-line DMT is not as common. We report two patients with RRMS who experienced a relapse after the accelerated elimination period (AEP) of teriflunomide and confirmation of negative plasmatic levels (<0.02 µg/ml). In cases of risk of MS activity, we should not wait for teriflunomide negative plasmatic levels confirmation before starting the next DMT to reduce the risk of relapse.

Auditory spatial receptive fields created by multiplication.

Examples of multiplication by neurons or neural circuits are scarce, although many computational models use this basic operation. The owl's auditory system computes interaural time (ITD) and level (ILD) differences to create a two-dimensional map of auditory space. Space-specific neurons are selective for combinations of ITD and ILD, which define, respectively, the horizontal and vertical dimensions of their receptive fields. A multiplication of separate postsynaptic potentials tuned to ITD and ILD, rather than an addition, can account for the subthreshold responses of these neurons to ITD-ILD pairs. Other nonlinear processes improve the spatial tuning of the spike output and reduce the fit to the multiplicative model.

Computerized registry of patients with hemorrhagic hereditary telangiectasia (RiHHTa Registry) in Spain: Objectives, methods, and preliminary results. / Registro informatizado de la telangiectasia hemorrágica hereditaria (Registro RiHHTa) en España: objetivos, métodos y resultados preliminares.

INTRODUCTION: Hereditary hemorrhagic telangiectasia (HHT) is a rare disease with autosomal dominant inheritance that causes systemic vascular affectation. MATERIAL AND METHOD: After development a multicentric Spanish national registry, called RiHHTa, main clinical manifestations and diagnostic procedures of the first patients introduced are described. RESULTS: 141 patients were included, of which 91 (64.5%) were women. The mean age at diagnosis was 42 years. Mutations in the ACVRL1 gene predominated over the ENG gene. The initial symptom was recurrent epistaxis in 130 (92.2%) patients and in three (2.1%), brain abscess. Pulmonary arteriovenous (AV) fistula were detected in 36 (45%) of the 79 patients who underwent thoracic CT angiography. The contrast echocardiography detected very few bubbles (grade I) or none, in 36 (45%) of these 79 affected patients. In 43 (67.2%) of the 64 patients with an abdominal CT angiography, hepatic vascular malformations were detected, mostly telangiectasias, AV and arterio-portal fistula, and extrahepatic in 14 (10%) subjects. More than half of the patients were screened for the presence of brain arteriovenous malformations which was found in 3.9% of them. The upper part of the intestinal tube was the most (95%) affected region. CONCLUSION: The RiHHTa Registry allows improving the management of patients with HHT. An inadequate use of thoracic CT angiography and the usefulness of abdominal CT angiography has been detected in order to define subtypes of hepatic vascular involvement and detect extrahepatic vascular involvement.

[Clinical features of familial Creutzfeldt-Jakob disease and the E200K mutation in Spain]. / Características clínicas de la enfermedad de Creutzfeldt-Jakob familiar y mutación E200K en España.

INTRODUCTION: Creutzfeldt-Jakob disease (CJD) is an infrequent pathology affecting the central nervous system (about 1/1,000000) that has a subacute progression and, for the time being, a fatal prognosis. The familial forms account for between 5-10% of cases and one of the most frequent is that produced by the E200K mutation of prion protein gene (PRNP), which has not been reported in Spanish families although Spain is considered to be part of the expansion circuit of the mutation. CASE REPORTS: We report on a Spanish family with three cases of CJD. The disease affected three females (our patient and two paternal aunts), who started with dementia, myoclonias, gait disorders and cortical blindness at the ages of 61, 53 and 55 years. Progress in all three cases was torpid and the symptoms advanced in a short time. Results of the complementary tests that were carried out were normal, except for the electroencephalogram, which was compatible with CJD in all three cases, and the imaging tests, which revealed cortical-subcortical atrophy. A confirmatory diagnosis was reached from a biopsy, the clinical picture and the family history in the cases of the paternal aunts and from a genetic study of our patient, which confirmed the E200K mutation. CONCLUSIONS: This family confirms the presence of familial forms of CJD in Spain, more specifically the E200K mutation, and highlights the role of Spain in the possible transmission of this mutation.

Autoinflammatory diseases in adults. Clinical characteristics and prognostic implications. / Enfermedades autoinflamatorias en el adulto. Características clínicas e implicaciones pronósticas.

Autoinflammatory diseases are clinical conditions with inflammatory manifestations that present in a periodic or persistent manner and are caused by acquired or hereditary disorders of the innate immune response. In general, these diseases are more common in childhood, but cases have been reported in adults and are therefore important for all specialists. There are few references on these diseases in adults due to their low prevalence and underdiagnosis. The aim of this study is to review the scientific literature on these disorders to systematise their clinical, prognostic and treatment response characteristics in adults.

Current diagnosis and treatment of Castleman's disease.

Castleman's disease is not just a single disease but rather an uncommon, heterogeneous group of nonclonal lymphoproliferative disorders, which have a broad spectrum of clinical expression. Three histological types have been reported, along with several clinical forms according to clinical presentation, histological substrate and associated diseases. Interleukin-6, its receptor polymorphisms, the human immunodeficiency virus and the human herpes virus 8 are involved in the etiopathogenesis of Castleman's disease. The study of this disease has shed light on a syndrome whose incidence is unknown. Despite recent significant advances in our understanding of this disease and the increasing therapeutic experience with rituximab, tocilizumab and siltuximab, there are still difficult questions concerning its aetiology, prognosis and optimal treatment.

Cochlear and neural delays for coincidence detection in owls.

The auditory system uses delay lines and coincidence detection to measure the interaural time difference (ITD). Both axons and the cochlea could provide such delays. The stereausis theory assumes that differences in wave propagation time along the basilar membrane can provide the necessary delays, if the coincidence detectors receive input from fibers innervating different loci on the left and right basilar membranes. If this hypothesis were true, the left and right inputs to coincidence detectors should differ in their frequency tuning. The owl's nucleus laminaris contains coincidence detector neurons that receive input from the left and right cochlear nuclei. Monaural frequency-tuning curves of nucleus laminaris neurons showed small interaural differences. In addition, their preferred ITDs were not correlated with the interaural frequency mismatches. Instead, the preferred ITD of the neuron agrees with that predicted from the distribution of axonal delays. Thus, there is no need to invoke mechanisms other than neural delays to explain the detection of ITDs by the barn owl's laminaris neurons.

Methylphenidate and amphetamine modulate differently the NMDA and AMPA glutamatergic transmission of dopaminergic neurons in the ventral tegmental area.

Behavioral and neurochemical studies suggest that the induction of behavioral sensitization to psychostimulants involves transient changes at the synapses of the ventral tegmental area's dopaminergic neurons (VTA-DA). Differences in the behavioral response to amphetamine (Amph) and methylphenidate (MPD) were observed. In an attempt to understand these behavioral differences at the neuronal level, the dose-response characteristics of these two psychostimulants on electrophysiologically identified VTA-DA neurons at the glutamatergic synapse were investigated. Miniature excitatory post-synaptic currents (mEPSCs) and electrically induced EPSCs were recorded from horizontal midbrain slices of rats that had been pretreated intraperitoneally (i.p.) with saline (control), Amph (2.5, 5.0, 10.0 or 20.0 mg/kg), or MPD (2.5, 5.0, 10.0 or 20.0 mg/kg) 24 h before the recording. Perfusion of Amph through the bath (2.5, 5.0, 10.0 or 20.0 microM) increased the frequency (p<0.01) and the amplitude (p<0.05) of mEPSCs in dose-response characteristics, while MPD perfusion through the bath (2.5, 5.0, 10.0, or 20.0 microM) increased only the frequency (p<0.05) of the mEPSC. Both psychostimulants increased the prefrontal cortex's (PFC) glutamatergic EPSC in the VTA-DA neurons. However, only the higher doses of MPD induced significant effects (p<0.05) on the N-methyl-D-aspartate (NMDA) receptor-mediated EPSC but had no effects on the EPSC mediated by alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA/kainate) receptors. Contrarily, Amph increased both kinds of mediated EPSC, but mainly the EPSC mediated by AMPA/kainate receptors (p<0.01). These electrophysiological differences could represent the underlying mechanism responsible for the differences of behavioral effects, such as behavioral sensitization, elicited by MPD and Amph.

Choroidal neovascularization secondary to choroideremia.

CASE REPORT: The case is presented of a 30 year-old man, with night blindness and decreased visual acuity (VA) in both eyes, but more significant in the left eye (LE) of 20/100. Lesions consistent with choroideremia and LE macular hemorrhage was observed in the fundus. CNV was confirmed by OCT. A definitive diagnosis was obtained by genetic study. No treatment was given as the patient did not return. At 6 months there was a regression of CNV with VA 20/25 in the LE. CONCLUSIONS: CNV associated with choroideremia is uncommon. Treatment would antiangiogenic therapy, however spontaneous resolution is possible.

alpha-L-arabinofuranosidase production by Aspergillus nidulans.

The effects of some physico-chemical parameters on production of extracellular alpha-L-arabinofuranosidase by Aspergillus nidulans were examined. Highest levels of alpha-L-arabinofuranosidase were generated with cultures grown on 1% (w/v) purified beet pulp arabinan at 30 degrees C and at an initial pH of 7.0. The enzyme was shown to be very sensitive to the action of proteases. Zymogram overlay of a protein profile obtained by SDS-PAGE revealed the occurrence of a band (M(r) 36,000) exhibiting alpha-L-arabinofuranosidase activity. The isoelectric pH of the enzyme lay near 4.3. Temperature and pH optima for the activity of crude alpha-L-arabinofuranosidase preparations were 55 degrees C and 5.5, respectively. Enzyme activity was greatly reduced by thiol reagents such as Hg2+ and p-hydroxymercuribenzoate and showed a Km value of 2.7 mM on p-nitrophenyl alpha-L-arabinofuranoside as substrate.

Sleep and wakefulness modulation of the neuronal firing in the auditory cortex of the guinea pig.

Sleep-related changes-including modification in sensory processing-that influence brain and body functions, occur during both slow wave and paradoxical sleep. Our aim was to investigate how cortical auditory neurons behave during the sleep/waking cycle, and to study cell firing patterns in relation to the processing of auditory information without the interference of anesthetic drugs. We recorded single cells in the A region of the auditory cortex in restrained, chronically-implanted guinea pigs, and compared their evoked and spontaneous activity during sleep stages and quiet wakefulness. A new classification of the unit's responses to simple sound during wakefulness is presented. Moreover, a number of the neurons in the primary auditory cortex exhibited significant quantitative changes in their evoked or spontaneous firing rates. These changes could be correlated to sleep stages or wakefulness in 42.2% to 58.3% of the sampled neurons. A similar population did not show behavioral related changes in firing rates. Our results indicate that the responsiveness of the auditory system during sleep may be considered partially preserved. An important result was that spontaneous and evoked activity may vary in opposite directions, i.e. , the evoked activity could increase while the spontaneous activity decrease or vice versa. Then, a general question was proposed: is the increased spontaneous activity in the auditory cortex, particularly during PS, related to auditory hypnic 'images'? The studied cortical auditory neurons exhibit changes in their firing rates in correlation to stages of sleep and wakefulness. This is consistent with the hypothesis that a general shift in the neuronal networks involved in sensory processing occurs during sleep.

Auditory deprivation modifies sleep in the guinea-pig.

After destruction of both cochleae, a significant enhancement of both paradoxical sleep and slow wave sleep together with decreased wakefulness, were observed for up to 45 days. The sleep augmentation consisted of an increment in the number of episodes of both slow wave and paradoxical sleep rather than in the duration of single episodes. The partial isolation provoked by deafness is postulated as explanation. We suggest that the suppression of one input to a complex set of networks related to the sleep-waking cycle, introduce an imbalance that leads to sleep enhancement.

n-3 Fatty acids plus oleic acid and vitamin supplemented milk consumption reduces total and LDL cholesterol, homocysteine and levels of endothelial adhesion molecules in healthy humans.

BACKGROUND AND AIMS: Numerous studies suggest n -3 polyunsaturated fatty acids (n -3 PUFA) and oleic acid intake have beneficial effects on health including risk reduction of coronary heart disease. The purpose of this study was to evaluate the effect of a commercially available skimmed milk supplemented with n -3 PUFA, oleic acid, and vitamins E, B(6), and folic acid (Puleva Omega3) on risk factors for cardiovascular disease. (CVD). METHODS: Thirty volunteers were given 500 ml/day of semi-skimmed milk for 4 weeks and then 500 ml/day of the n -3 enriched milk for 8 further weeks. Plasma and LDL lipoproteins were obtained from volunteers at the beginning of the study (T(pre)), and at 4, 8 and 12 weeks. RESULTS: The consumption of n -3 enriched milk produced a significant decrease in plasma concentration of total and LDL cholesterol accompanied by a reduction in plasma levels of homocysteine. Plasma and LDL oxidability and vitamin E concentration remained unchanged throughout the study. A significant reduction in plasma levels of vascular cell adhesion molecule 1, and an increase in plasma concentration of folic acid were also observed. CONCLUSION: Daily intake of n -3 PUFA and oleic acid supplemented skimmed milk plus folic acid and B-type vitamins has favourable effects on risk factors for CVD.