Subcortical brain volume abnormalities in 2028 individuals with schizophrenia and 2540 healthy controls via the ENIGMA consortium.

The profile of brain structural abnormalities in schizophrenia is still not fully understood, despite decades of research using brain scans. To validate a prospective meta-analysis approach to analyzing multicenter neuroimaging data, we analyzed brain MRI scans from 2028 schizophrenia patients and 2540 healthy controls, assessed with standardized methods at 15 centers worldwide. We identified subcortical brain volumes that differentiated patients from controls, and ranked them according to their effect sizes. Compared with healthy controls, patients with schizophrenia had smaller hippocampus (Cohen's d=-0.46), amygdala (d=-0.31), thalamus (d=-0.31), accumbens (d=-0.25) and intracranial volumes (d=-0.12), as well as larger pallidum (d=0.21) and lateral ventricle volumes (d=0.37). Putamen and pallidum volume augmentations were positively associated with duration of illness and hippocampal deficits scaled with the proportion of unmedicated patients. Worldwide cooperative analyses of brain imaging data support a profile of subcortical abnormalities in schizophrenia, which is consistent with that based on traditional meta-analytic approaches. This first ENIGMA Schizophrenia Working Group study validates that collaborative data analyses can readily be used across brain phenotypes and disorders and encourages analysis and data sharing efforts to further our understanding of severe mental illness.

Dioxin in soil: bioavailability after ingestion by rats and guinea pigs.

Soil environmentally contaminated with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) was given by gavage to guinea pigs and rats. The development of a characteristic clinicopathologic syndrome in guinea pigs, the induction of aryl hydrocarbon hydroxylase in rats, and the presence of TCDD in the livers of both species show that TCDD in soil exhibits high biological availability after ingestion.

The mechanism for nonspecific lipase from rat pancreas.

Purified nonspecific lipase from rat pancreas appears to mediate the followin reaction sequence: (2) HE +nB in equilibrium HEBn; (2) HEBn + S inequilibrium HEBnS; (3) HEBnS IN EQUILIBRIUM EBnS' + ROH; (4) EBnS' + h2o vector HEBn + R'COO- + H+, where E equils enzyme, B equils bile salt, and S equils R'COOR. Evidence is presented for the occurrence, sequence and reversibility or irreversibility of the above four reactions. Also discussed are the activation energies for both a "good" and a "poor" substrate, the correlation between V and subsitituent function (o-) for a series of substituted benzoic acid esters, and the effects of steric hindrance. Studies of the incorporation of label from H2(18)O further detail the hydrolytic mechanism, and the effects of the physical state in which substrate is presented to the enzyme (micelles, emulsion, crude bulk phase, etc.) are discussed.

Tuberous sclerosis type 1: three novel mutations detected in exon 15 by a combination of HDA and TGGE.

Tuberous sclerosis (TSC) is an autosomal dominant disorder which is genetically heterogeneous with two genes, TSC1 and TSC2. TSC1 consists of 23 exons with exon 15 being the largest one comprising 559 bp. Representing 16% of the coding region exon 15 harbors 37% of the already identified point mutations in TSC1. Mutation screening of large DNA fragments as TSC1 exon 15 by SSCP has been a problem because of the low sensitivity of this method without subdivision. Therefore, we simultaneously performed heteroduplex analysis (HDA) and temperature gradient gel electrophoresis (TGGE) which are both more suitable for evaluation of fragments of this size. DNA samples of 159 patients with the clinical diagnosis of TSC were screened and a total of seven different mutations in nine unrelated cases were identified, including the three novel mutations 1754delT, 1836delT and R500Q. Comparing the two methods applied, HDA showed a higher sensitivity in detecting frameshift mutations, while TGGE seemed to be more sensitive for the detection of base exchanges. We conclude that the combination of these two methods is appropriate to reach a high degree of sensitivity for the detection of all types of small mutations in large DNA fragments.

Negative ion mass spectra of some polychlorinated 2-phenoxyphenols.

Polychlorinated 2-phenoxyphenols were studied by negative ion mass spectrometry. Common to almost all of the methane enhanced negative ion mass spectra were (M-1)-, (M-36-)-., (M-37)-, (M-72)-., and chorinated quinoxide ions. The (M-36)-. ion does not apparently form in a mechanism analogous to the thermal or photochemical ring closure of these compounds to form the chlorinated dioxins. The chlorinated quinoxide ion reflects the number of chlorines on the ring with hydroxy substituent. Collision-induced dissociation mass-analyzed ion kinetic energy spectra (CID-MIKES) from different isomers were qualitatively different in both the normal and charge reversed mode of operation. Comparison of these spectra with those from other classes of polychlorinated aromatic hydrocarbons such as the dioxins or the furans may reveal a common negative ion gas phase chemistry.

Adduct formation between the carcinogen N-acetoxy-2-acetylaminofluorene and synthetic polydeoxyribonucleotides.

The chemical carcinogen N-acetoxy-2-acetylaminofluorene (NA-AAF) was reacted with poly(dG-dC) - poly(dG-dC); poly dG - poly dC; poly(dA-dT) - poly (dA-dT); and poly dA - poly dT under a variety of conditions. Poly (dG-homo GC polymer and 10--20 more reactive the A + T polymers. Lowering the ionic strength increased the extent of reaction, while pH change (8.9 vs. 5.5) had only a small effect. If ionic strength was adjusted so that the two guanine-containing polymers showed equal thermal stability (as judged by Tm) then the alternating copolymer was 7 times as reactive as the homopolymer. In aggreement with previous investigators, the major product was found to be 8-(N-2-fluorenylacetamido) deoxyguanosine.

An introduction to digital cameras.

BACKGROUND AND OBJECTIVES: People in all walks of life are using digital cameras instead of the traditional film cameras. Reasons include simplicity of use, ease of development, ability to incorporate the pictures into documents, potential to edit the pictures easily, and capability to send them by e-mail. This article will briefly discuss digital cameras, how they work, what they can do, and what you should look for in one. Editor's Note: This is the fourth in a series of articles demonstrating and describing information technology. The articles include nontechnical information and are geared toward the computer novice with interest in regional anesthesia and pain medicine.

A mixture of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), and non-ortho polychlorinated biphenyls (PCBs) changed the lipid content of pregnant Long Evans rats.

Pregnant Long Evans rats received 1.0 microg/kg of dioxin toxic equivalents (TEQ) by oral gavage on the 15th gestational day (GD 15), using a dosing mixture that contained two polychlorinated dioxins, four polychlorinated furans and three non-ortho polychlorinated biphenyls (PCBs). Rats were sacrificed on GD 16, GD 21 and postnatal day 4 (PND 4). The lipid content of fetus, pup, placenta and maternal liver, serum and adipose tissue were determined. Treated GD 16 and GD 21 fetuses had identical lipid content to the control group, yet the lipid content of treated pups on PND 4 was 32% higher than that of the control group. On the other hand, the lipid content of placenta, liver, and serum from the treated dams was 44-50%, 24%, and 38% lower than that of the control group, respectively. Thus, a low-dose mixture of dioxin-like compounds can cause changes in lipid content. The lipid content of offspring was not affected until they were exposed via lactation.

The effect of ovary implants on juvenile hormone production by corpora allata of male Diploptera punctata.

In the cockroach Diploptera punctata, vitellogenic basal oocytes stimulate juvenile hormone production by the corpora allata. Experiments with males were designed to determine whether oocytes must grow vitellogenically in order to stimulate juvenile hormone production. Two ovarioles with vitellogenic basal oocytes were implanted into unoperated and sham-operated males that do not produce vitellogenin, and males with denervated corpora allata, that produce more juvenile hormone, and sometimes more vitellogenin. Males with corpora allata in similar conditions were injected with saline as controls. In males with denervated corpora allata compared to sham-operated and unoperated males, the implanted basal oocytes showed a greater increase in length, protein, and vitellin content. Juvenile hormone synthesis by denervated corpora allata in males with ovariole implants was greater than in controls. In 10 of 50 males with denervated corpora allata in which one or no ovarioles grew, juvenile hormone production was not higher than in controls. This suggests that if sufficient juvenile hormone is not present to produce vitellogenin, or oocytes do not take vitellogenin up, juvenile hormone production is not stimulated. In sham-operated males implanted with ovarioles, no difference was detected in juvenile hormone synthesis compared to controls. However when unoperated males were used a significant increase was detected. This suggests that intact nerves from the brain to the corpora allata restrained juvenile hormone production so that ovarioles could elicit only slight stimulation of the corpora allata, and oocytes continued vitellogenesis but more slowly than in denervated males. Thus the extent of vitellogenesis appears to determine the ability of ovaries to stimulate juvenile hormone production.

Why multilayer graphene on 4H-SiC(0001[over ]) behaves like a single sheet of graphene.

We show experimentally that multilayer graphene grown on the carbon terminated SiC(0001[over ]) surface contains rotational stacking faults related to the epitaxial condition at the graphene-SiC interface. Via first-principles calculation, we demonstrate that such faults produce an electronic structure indistinguishable from an isolated single graphene sheet in the vicinity of the Dirac point. This explains prior experimental results that showed single-layer electronic properties, even for epitaxial graphene films tens of layers thick.