Cortical gray matter volume deficits in schizophrenia: a replication

We sought to replicate an earlier finding of widespread deficit in cortical gray matter in schizophrenia by testing new samples of 22 schizophrenic patients and 27 controls between the ages of 21-46 years. Brain values for both patients and controls were standardized against age and head size norms derived from a larger control group (n = 73) spanning a wider age range (21-70). Compared to the new age-matched controls, the new schizophrenic sample showed a deficit in gray matter volume affecting the cortex as a whole and enlargement of the lateral and third ventricles. Thus, widespread cortical gray matter deficit is a replicable feature of the brain dysmorphology of schizophrenia in young to middle-aged men.     

A fosmid-based genomic map and identification of 474 genes of the hyperthermophilic archaeon Pyrobaculum aerophilum

Polydimethylsiloxane (PEP) is widely used in medical prostheses and therefore is in contact with plasma and secretory proteins. Two pair of globular proteins, lactoferrin (Lf) and transferrin (Trf), and bovine IgG1 and IgG2a, which differ substantially between pair members in their pl, were used to study the interaction of a PEP widely used in breast implants and soluble protein. Studies were done using iodinated proteins over a concentration range that resulted in an apparent protein monolayer. Secondary incubations with dilute protein solutions were needed to form the monolayer on PEP, possibly as a consequence of micro air bubbles trapped on its highly textured surface as shown by atomic force microscopy. Immunoassay quality polystyrene microtiter wells were used as controls. Adsorption studies were routinely performed at pH 4, 7 and 10 and at ionic strengths corresponding to 0.95, 9.5 and 90.0 mS. The protein capture capacity (PCC) of PEP for Lf and Trf was optimal at physiological pH and ionic strength and comparable under these conditions to that of Immulon 2 (Imm 2) microtiter wells. While increasing the ionic strength and pH further increases the PCC of Imm 2 for Lf and Trf, this markedly lowered the PCC of PEP for these proteins suggesting that initial polar interactions may precede subsequent hydrophobic bonding to PEP. This was tested using a hydrophilic variant of PEP, which when tested in a 90.0 mS buffer, showed a > five-fold lower PCC at neutral and alkaline pH. The greatly reduced PCC of the hydrophilic variant might also suggest that hydrophilic variants of silicone would be more biocompatible than those currently used. The PCC of PEP for the IgGs was less than that of Imm 2 but still optimal at physiological conditions. Consistent with the data on Lf/Trf, PCC progressively decreased with increasing ionic strength at alkaline pH. Differences in pl between the protein pairs had only a marginal effect on the PCC of PEP. Monolayer adsorption on both PEP and Imm 2 was slowly reversible and greater in the presence of free ligand (< 2% in 16 h) suggesting that the process follows Mass Law principles. However, even in the presence of non-ionic detergent and free ligand, 85-90% remained bound on either surface. Thus, desorption of proteins in the monolayer should not complicate subsequent immunochemical studies conducted on adsorbed monolayers.     

Compartmentation of the granular layer of the cerebellum

Numerous studies have demonstrated that the cerebellum is highly compartmentalized. In most cases, compartmentation involves the Purkinje cells and the molecular layer, but there is also substantial evidence that the granular layer is subdivided into a large number of highly reproducible modules. We first review the evidence for a modular granular layer. Compartmentation of the granular layer has been revealed both functionally and structurally. First, tactile receptive field mapping has revealed numerous discrete functional modules within the granular layer. The molecular correlates of the receptive fields may be the compartments revealed by histological staining of the cerebellum for several enzymes and antigens. The structural substrate of the receptive fields is the mossy fiber afferent projection map, and anterograde tracing of various mossy fiber projections shows afferent terminals in parasagittal bands within the granular layer that are topographically aligned with the Purkinje cell compartments. Based on this evidence we argue that the cerebellum consists of many hundreds of reproducible structural/functional modules, and that a modular organization is a prerequisite for the efficient parallel processing of information during motor control. The complex organization of the adult granular layer implies elaborate developmental mechanisms. In the second part of the review we consider five developmental models to generate the modular organization of the adult granular layer: 1) the external granular layer is heterogeneous, and its topography translates directly into a modular granular layer; 2) granular layer modules are clones, derived from single external granular layer precursors; 3) modules in the granular layers are a secondary epigenetic response to the compartmentation of the Purkinje cells; 4) modules are secondary to the compartmentation of the afferent terminal fields; 5) modules are sculpted by activity-dependent processes.     

Pathology of lung cancer

The aim of this study was to assess the repeatability of the program-usage in everyday listening situations. A blind field test was used. The Widex Quattro (WQ) system served as a model for multiple memory hearing aids (linear amplification) Eleven experienced WQ wearers (41-73 years) with mild to moderate, recruiting, cochlear hearing losses participated. Eight of them regularly used all four available programs (all used at least three programs). The participants stated in duplicate the best hearing aid program in 15 real-world listening situations. The percentage of subjects who selected identical programs (repeatability) surpassed the level corresponding to pure guess under almost all listening conditions (14). Maximum repeatability (100%) was achieved by the five subjects who visited an industrial environment twice. Interestingly, the repeatability exceeded 70% in demanding listening situations such as: party, conversation in group, etc. Support for this high repeatability was given by a distinct improvement in the mean aided speech-to-noise threshold (3.7 dB, p < 0.005).     

气相生长炭纤维增强酚醛树脂制炭/炭复合材料及其物性之研究

以气相生长炭纤维含浸酚醛树脂后经炭化及石墨化处理，制成炭／炭复合材料。观察了不同纤维百分含量的复合材料在升温过程的微细结构及物性之变化，探讨了其强度及电性的变化，并以扫瞄式电子显微镜（SEM）观察破断表面，观察各种复合材料经不同温度处理后之破坏行为。研究结果显示，以气相生长炭纤维所制复材经温度处理后，可以改善其抗弯强度及导电性，最佳纤维含量质量分数为0．5％。超过此比率后，制成之复合材料无论是空孔率或强度皆呈下降。     

Kinetics of lysozyme refolding: structural characterization of a non-specifically collapsed state using time-resolved X-ray scattering

We report time-resolved small angle X-ray scattering (SAXS) studies of the structural characteristics of the collapsed state of lysozyme from henegg white (HEL) obtained on initiating refolding by rapidly changing solvent conditions from 8 M to 1.1 M urea at pH 2.9. At this reduced pH the lifetime, of about one second, of the non-specifically collapsed ensemble is considerably prolonged relative to its value at pH 5.2. The SAXS studies are combined with time resolved measurements of tryptophan fluorescence and of the rate of formation of native molecules using interrupted refolding experiments. We observe large burst phase changes in intrinsic tryptophan fluorescence and in the radius of gyration (Rg) which is reduced from 22 A in the fully unfolded state to approximately 19 to 20 A. Subsequent decrease of the Rg to the value for native lysozyme (15 A) follows the time course of formation of native molecules. Single exponential fits to the singular value decomposition (SVD) components of the SAXS data allow reconstruction of the SAXS profile at early time points of refolding. The results of this analysis suggest a globular shape of the collapsed state. A similar fit to the forward scattering amplitude, I(0), suggests that the collapsed state has a solvent accessible surface area which is considerably increased relative to that of the native protein. These results show directly that the non-specifically collapsed state formed during the burst phase in lysozyme refolding indeed represents a molecular compaction and a change in shape from a fully denatured random coil state (albeit restricted by disulfide bonds) to an ensemble of globular conformations which, however, have not yet formed a solvent-protected hydrophobic core.     

Intestinal and gastric bypass. Changes in intestinal microecology after surgical treatment of morbid obesity in man

Jejunal bacterial flora, bile acid deconjugation, and breath hydrogen and methane excretion were studied in nine patients with end-to-side and nine patients with end-to-end jejunoileostomy and in eight patients with gastric bypass. Bacterial numbers did not differ significantly between healthy controls and any of the patient groups. Production of fermentation gases in anaerobic cultures supplemented with carbohydrates did not occur with jejunal secretions from healthy controls but was found in all intestinal bypass patients and half the gastric bypass patients. Bacterial bile acid deconjugation activity was significantly higher in end-to-side compared with end-to-end jejunoileostomy patients. In gastric bypass patients bile acid deconjugation was not significantly affected. Breath hydrogen after glucose ingestion was abnormal in six patients with end-to-side and three with end-to-end jejunoileostomy and in six of the patients subjected to gastric bypass. The highest values were found in the later group. Breath methane, which is found in one third of a healthy population, was absent in all 18 patients with intestinal bypass, and this may indicate that a change occurs even in the colonic microflora after this operation. Both intestinal and gastric bypass may change the small-bowel microflora, with the greatest changes occurring after end-to-side jejunoileostomy and the least changes after gastric bypass.     

A phantom for diffusion-weighted imaging of acute stroke

A tissue phantom for diffusion-weighted imaging was developed, basing its contrast between two compartments on different apparent diffusion coefficients, without contrast due to T2 relaxation and proton density. These contrast properties of the phantom simulate the situation found in normal gray matter and areas of acute ischemia. A possible application of the phantom was demonstrated for the investigation of the accuracy of volume measurements based on diffusion-weighted images.