Altered and asymmetric default mode network activity in a "hypnotic virtuoso": an fMRI and EEG study.

Very highly hypnotizable subjects are rare, easily induced, and able to manifest the whole spectrum of hypnotic phenomena, including post-hypnotic amnesia. The aim of this study was to detect and localize by means of quantitative functional MRI and EEG changes in cortical activity during hypnosis induction and deep "pure hypnosis" in a hypnotic "virtuoso" subject. We focused on areas forming the default mode network (DMN), since previous studies found that very highly suggestible subjects in hypnosis showed decreased activity in anterior DMN. During undisturbed hypnosis, our "virtuoso" subject showed not only detectable changes in DMN, but also peculiar activations of non-DMN areas and hemispheric asymmetries of frontal lobe connectivity. Our findings confirm that hypnosis is associated with significant modulation of connectivity and activity which involve the DMN but are not limited to it, depending on the depth of the hypnotic state, the type of mental content and emotional involvement.

DNA fingerprinting and analysis of population structure in the chestnut blight fungus, Cryphonectria parasitica.

We analyzed DNA fingerprints in the chestnut blight fungus, Cryphonectria parasitica, for stability, inheritance, linkage and variability in a natural population. DNA fingerprints resulting from hybridization with a dispersed moderately repetitive DNA sequence of C. parasitica in plasmid pMS5.1 hybridized to 6-17 restriction fragments per individual isolate. In a laboratory cross and from progeny from a single perithecium collected from a field population, the presence/absence of 11 fragments in the laboratory cross and 12 fragments in the field progeny set segregated in 1:1 ratios. Two fragments in each progeny set cosegregated; no other linkage was detected among the segregating fragments. Mutations, identified by missing bands, were detected for only one fragment in which 4 of 43 progeny lacked a band present in both parents; no novel fragments were detected in any progeny. All other fragments appeared to be stably inherited. Hybridization patterns did not change during vegetative growth or sporulation. However, fingerprint patterns of single conidial isolates of strains EP155 and EP67 were found to be heterogenous due to mutations that occurred during culturing in the laboratory since these strains were first isolated in 1976-1977. In a population sample of 39 C. parasitica isolates, we found 33 different fingerprint patterns with pMS5.1. Most isolates differed from all other isolates by the presence or absence of several fragments. Six fingerprint patterns each occurred twice. Isolates with identical fingerprints occurred in cankers on the same chestnut stems three times; isolates within the other three pairs were isolated from cankers more than 5 m apart. The null hypothesis of random mating in this population could not be rejected if the six putative clones were removed from the analysis. Thus, a rough estimate of the clonal fraction of this population is 6 in 39 isolates (15.4%).

Proton magnetic resonance spectroscopy and intracranial tumours: clinical perspectives.

Proton magnetic resonance spectroscopy (1H-MRS) was applied to characterize intracranial tumours of different hystological types. Seventy patients with intracranial neoplasms were studied before receiving surgery, radiotherapy or chemotherapy. All tumours were characterized by reduced or absent N-acetylasparate and increased signal from choline-containing compounds. Distinctive patterns were observed only for primitive brain neoplasms; high-grade gliomas were differentiated from low-grade ones by higher levels of choline-containing compounds. The metabolic aspects of metastatic lesions were similar to high-grade gliomas. These results, together with the limitations of 1H-MRS and future applications are reviewed.

Benign versus secondary-progressive multiple sclerosis: the potential role of proton MR spectroscopy in defining the nature of disability.

PURPOSE: We determined the clinical utility of proton MR spectroscopy in defining the extent of disability in benign versus secondary-progressive multiple sclerosis (MS). METHODS: Thirty patients with clinically definite MS, including 16 patients with benign MS and 14 with secondary-progressive MS, and a group of 13 healthy volunteers were studied with combined stimulated-echo acquisition mode proton MR spectroscopy and MR imaging (all patients received contrast material). RESULTS: Acute enhancing lesions of benign and secondary-progressive MS were characterized by a reduction in N-acetylaspartate (NAA)/choline and NAA/creatine and an increase in inositol compounds/creatine as compared with normal white matter. Such variations were also detected in chronic unenhancing lesions in patients with secondary-progressive MS, although they were not found in chronic unenhancing lesions in patients with benign MS. Chronic lesions of the two forms of the disease have significative differences in NAA and inositol signals. CONCLUSION: Proton MR spectroscopy is able to show metabolic changes occurring in the white matter of patients with MS. Such changes differ according to the phase (acute versus chronic) and the clinical form (benign versus secondary-progressive) of the disease.

¿Lo sabes todo sobre epistaxis? / Do you know all about epistaxis?

La epistaxis es un síntoma muy común es muestra práctica diaria, aproximadamente el 60% de la población ha tenido al menos un episodio en algún momento de su vida pero solo 6% precisó atención médica. La mayoría de episodios son limitados y benignos pero, en ocasiones, nos encontramos con casos que pueden resultar fatales.

Nosebleed is a really common symptom, about 60% of the population has had at least one episode at some point in their lives but only 6% required medical attention. Most episodes are limited and benign but in some rare cases, it could be deathly.

Spatial analysis of nuclear and mitochondrial RFLP genotypes in populations of the chestnut blight fungus, Cryphonectria parasitica.

Spatial structure of both nuclear and mitochondrial RFLPs were studied in several populations of the chestnut blight fungus, Cryphonectria parasitica, using a variety of spatial autocorrelation tests designed to detect nonrandom patterns. Fungal individuals were sampled from cankers on infected chestnut trees, and the location of each tree was mapped. Single-locus nuclear RFLPs, nuclear fingerprints, and mitochondrial DNA haplotypes were determined for each individual. Individuals with the same DNA fingerprint genotypes occurred closer together than would be expected at random in four of the five plots, while mitochondrial DNA haplotypes were aggregated in all five plots. Genetic distances between individuals, expressed as one minus the proportion of shared restriction fragment size classes for fingerprints and mitochondrial haplotypes, were significantly correlated with Euclidean distances between individuals in four of the five populations, but these correlations were very weak (r < 0.18). The same DNA fingerprint and single-copy nuclear RFLP alleles occurred on the same trees or immediately neighbouring trees more often than would be expected at random. Most of the aggregation for all three genetic markers occurred among individuals within the same cluster of chestnut stems or on neighbouring trees. Lack of spatial autocorrelation in one population was probably due to sampling on a larger scale that was too coarse to detect any patterns. Significant aggregation of genotypes in C. parasitica is most likely caused by some degree of restricted dispersal within populations. The implications of restricted dispersal are discussed in relation to the breeding system and isolation by distance in populations of C. parasitica.

Amplified fragment length polymorphism (AFLP) fingerprinting of symbiotic fungi cultured by the fungus-growing ant Cyphomyrmex minutus.

A PCR-based fingerprinting technique based on amplified fragment length polymorphisms (AFLP) is used to screen symbiotic fungi of the fungus-growing ant Cyphomyrmex minutus for genetic differences. AFLP fingerprints reveal several fungal 'types' that (a) represent distinct clones propagated vegetatively by the ant, or (b) correspond to free-living fungi that may be acquired by the ant. Fungal types identified by AFLP fingerprints correspond to vegetative-compatibility groups established previously, suggesting that vegetative compatibility can be used as a crude indicator of genetic differences between fungi of C. minutus.

Modern imaging techniques in GH secretory disorders.

Magnetic resonance images of the pituitary-hypothalamic area in patients with GH secretory disorders, divided into two groups (hypersecretory and hyposecretory), were studied. In the first group there were 42 patients with pituitary adenoma; size, signal characteristics, direction of growth, and type of enhancement were analyzed and compared with similar studies in 40 age and sex matched control patients with non-GH secreting pituitary adenomas. No significant differences were found except for a higher frequency of chiasm involvement and a more pronounced contrast enhancement in the control group. The hyposecretory group was composed of 101 patients with congenital idiopathic growth hormone deficiency (CIGHD). MR revealed morphological abnormalities consisting of hypoplastic anterior pituitary and ectopic posterior pituitary (PPE) in 59 patients, without evidence of a complete pituitary stalk; in 42 patients the posterior pituitary was in normal position and the pituitary stalk visible. The group with PPE showed a greater frequency of multiple pituitary hormone deficiency (51% vs 12%), breech delivery (30% vs 7%) and associated congenital brain anomalies (12% vs 7%). These data suggest that CIGHD could be the result of a congenital midline brain anomaly in a significant proportion of patients.

Pathogenetic and prognostic features of lacunar transient ischaemic attack syndromes.

Lacunar ischaemic stroke syndromes are a well defined subgroup of ischaemic strokes. To determine whether a similar subgroup can be identified among patients with transient ischaemic attacks (TIAs) we studied prospectively 102 consecutive patients within 24 hours of their first TIA. Based on their history they were classified as lacunar TIA syndromes (LTIAS; n = 45) if isolated motor or sensory symptoms or their combination had involved at least two of three body parts (face, arm, leg), whereas all other subjects were grouped as non-lacunar TIA syndromes (NLTIAS; n = 57). All patients were investigated according to a standardised protocol and followed up for an average of 51.1 months. Cardiac and arterial sources of thromboembolism were more frequent among NLTIAS (p = 0.0001). Survival curve analysis demonstrated that LTIAS had a significantly lower long term mortality and incidence of major vascular events. In a multivariate regression analysis, the type of TIA (that is, NLTIAS) was an independent predictor of stroke or death. LTIAS share the same distinct pathogenetic and prognostic features of lacunar ischaemic stroke syndromes. These findings have implications for management of TIAs and for studies of their natural history and treatment.

Molecular cloning, germ-line transformation, and transcriptional analysis of the zeste locus of Drosophila melanogaster.

Approximately 170 kilobase pairs (kb) of contiguous DNA sequences derived from bands 3A3,4 of the Drosophila melanogaster X chromosome have been isolated by molecular cloning. Sequences required for the wild-type expression of the zeste locus are located within a 6-kb fragment of this chromosomal region, as shown by phenotypic rescue of zeste mutants in P element-mediated germ-line transformation. Expression of zeste is correlated with a 2.2-kb poly(A)+ RNA species transcribed at all postzygotic stages of Drosophila development. Many zeste alleles, including several producing neomorphic phenotypes, are not associated with detectable rearrangements of DNA.

Varicella-zoster virus (VZV) DNA in cerebrospinal fluid of patients infected with human immunodeficiency virus: VZV disease of the central nervous system or subclinical reactivation of VZV infection?

To identify varicella-zoster virus (VZV) infections of the nervous system in patients infected with human immunodeficiency virus (HIV), polymerase chain reaction (PCR) analysis of cerebrospinal fluid (CSF) samples from 514 consecutive HIV-infected patients with neurological disease was performed to detect VZV DNA. VZV DNA was detected in CSF of 13 (2.5%) of 514 patients. Four of 13 patients had VZV encephalitis or meningoencephalomyelitis. These four patients received intravenous acyclovir therapy; CSF became negative for VZV DNA and clinical conditions improved for two, whereas CSF remained positive for VZV DNA and clinical conditions worsened until death for two. In nine of 13 patients, the neurological symptoms were likely caused by other simultaneous HIV-related complications in the central nervous system. After intravenous therapy with high doses of acyclovir or foscarnet, VZV was cleared from CSF in eight of nine patients. VZV DNA can be detected in CSF of HIV-infected patients in association with either manifestations of neurological VZV disease or subclinical reactivation of VZV infection. Antiviral treatment may be effective in suppressing VZV replication in the nervous system.