Inhibition of plaque formation, rosette formation and phagocytosis by alpha globulin

The immunosuppressive effect of an alpha globulin fraction isolated from normal human plasma is described.

The administration of this material to rats suppressed both the primary and secondary antibody responses against sheep erythrocytes. Alpha globulin also depressed the ability of mice spleen cells to confer immunity to irradiated isologous recipients.

The in vitro addition of alpha globulin to mouse peritoneal leucocytes (MPL) and whole human blood caused a significant reduction of their phagocytic activity against bacteria.

The mode of action of alpha globulin in relation to its immunosuppressive activity is discussed.

     

White Matter Fiber Tracking Computation Based on Diffusion Tensor Imaging for Clinical Applications

Fiber tracking allows the in vivo reconstruction of human brain white matter fiber trajectories based on magnetic resonance diffusion tensor imaging (MR-DTI), but its application in the clinical routine is still in its infancy. In this study, we present a new software for fiber tracking, developed on top of a general-purpose DICOM (digital imaging and communications in medicine) framework, which can be easily integrated into existing picture archiving and communication system (PACS) of radiological institutions. Images combining anatomical information and the localization of different fiber tract trajectories can be encoded and exported in DICOM and Analyze formats, which are valuable resources in the clinical applications of this method. Fiber tracking was implemented based on existing line propagation algorithms, but it includes a heuristic for fiber crossings in the case of disk-shaped diffusion tensors. We successfully performed fiber tracking on MR-DTI data sets from 26 patients with different types of brain lesions affecting the corticospinal tracts. In all cases, the trajectories of the central spinal tract (pyramidal tract) were reconstructed and could be applied at the planning phase of the surgery as well as in intraoperative neuronavigation.     

T cell developmental defects in 'viable motheaten' mice deficient in SHP-1 protein-tyrosine phosphatase. Developmental defects are corrected in vitro in the presence of normal hematopoietic-origin stromal cells and in vivo by exogenous IL-7

Defects in the gene that encodes SHP-1 protein tyrosine phosphatase result in multiple hematopoietic abnormalities and generalized autoimmunity in viable motheaten (me(v)) mice. These mice also exhibit early thymic involution and abnormalities in T cell development. Here, we describe the use of fetal thymic organ culture (FTOC) and bone marrow adoptive transfer to study the effects of SHP-1 deficiency on thymocyte development. Chimeric FTOC established with normal bone marrow placed onto deoxyguanosine-treated fetal thymic lobes or onto scid fetal thymic lobes generated T cells. Bone marrow from SHP-1-deficient me(v)/ me(v) mice generated decreased numbers of T cells in chimeric FTOC established using deoxyguanosine-treated thymi but generated normal numbers in chimeric FTOC established using scid thymi. However, scid fetal thymi seeded with me(v)/ me(v) bone marrow also exhibited morphological abnormalities and contained elevated numbers of macrophages. Addition of IL-7 to me(v)/ me(v) bone marrow-seeded scid FTOC led to increased cell numbers, particularly of macrophages. Intrathymic injection of IL-7 partially restored the ability of progenitor cells in me(v)/ me(v) bone marrow to populate the thymus of adoptive recipients. We conclude that abnormal T cell development in me(v)/ me(v) mice may in part be due to defects in the ability of bone marrow-derived accessory cells to provide bioavailable IL-7 to developing thymocytes.     

Distress and DNA repair in human lymphocytes

This research assessed differences in DNA repair in lymphocytes from high-and low-distressed individuals. A median split on Minnesota Multiphasic Personality Inventory (MMPI) Scale 2 divided 28 newly admitted nonpsychotic psychiatric inpatients into high- and low-distress subgroups. The high-distress subgroup had significantly poorer DNA repair in lymphocytes exposed to X-irradiation than low-distress subjects. We also found that lymphocytes obtained from this psychiatric sample had significantly poorer DNA repair than lymphocytes from nonpsychiatric control subjects when compared 5 hr after X-irradiation. A high level of distress therefore appears to be associated with significant dysfunctional differences at the molecular level which may have important implications for health. These data provide evidence for a direct pathway through which distress could influence the incidence of cancer.This research was funded in part by General Molecular Applications, Inc., the Bremer Foundation, the Samuel J. Roessler Fund, and Comprehensive Cancer Center Core Grant CA-16068-09.     

太空发育鸡胚的前庭感受器细胞形态学研究

为了探讨太空微重力对鸡胚前庭感觉上皮细胞的形态发育的影响 ,选取在航天飞机 (STS-2 9)发育鸡胚和地面发育鸡胚各两只 ,利用计算机显微测量技术分别测量椭圆囊和球囊的毛细胞、支持细胞核的切面面积、周长、形状系数。太空发育鸡胚的球囊支持细胞核的切面面积、周长显著大于地面组 ,形状系数无差异 ;太空发育鸡胚的椭圆囊支持细胞核的切面面积、周长、形状系数以及椭圆囊和球囊毛细胞的切面面积、周长与地面发育鸡胚相比无明显差异。微重力可能对球囊支持细胞核的体积发育有影响 ,对椭圆囊和球囊的毛细胞以及椭圆囊支持细胞核的形态发育无影响。     

Plasticity of the medial prefrontal cortex: Facilitated acquisition of intracranial self-stimulation by pretraining stimulation

Prior electrical stimulation of the medial prefrontal cortex MFC facilitated the subsequent acquisition of intracranial self-stimulation (ICSS) from the same MFC electrode site. Stimulations that were spaced over a period of six days were more effective in producing this facilitation than the same number of stimulations delivered over a two day period. These data suggest that the rewarding effects of MFC stimulation may involve some process akin to the kindling phenomenon and as such may provide insights in the neuronal modifications thought to underlie learning and memory.     

Neurobehavioral phenotype in carriers of the fragile X premutation

There have been contradictory findings in the fragile X (fraX) literature about possible neurocognitive and psychological symptoms due to the fraX premutation (pM). The purpose of the present study was to investigate the relationship between CGG repeat length and neurobehavioral functioning in carriers of the fraX pM. Eighty‐five female carriers of the pM with allele sizes ranging from 59–166 were administered a comprehensive IQ test (WAIS‐III) and completed a questionnaire designed to measure psychopathology (Symptom Checklist (SCL)‐90‐R). No relationship between allele size and cognition was identified. A significant negative relationship between allele size and age was found, as well as a positive relationship between allele size and depression. Follow‐up analyses separating small and large allele sizes (below and above 100 CGG repeats) indicated that individuals with larger allele sizes scored significantly higher on the Interpersonal Sensitivity and Depression subscales of the SCL‐90‐R. Despite the limitation of few individuals with high CGG repeat lengths, our findings suggest that females with larger premutated alleles (≥ 100 repeats) display some clinical manifestations of fraX syndrome. © 2001 Wiley‐Liss, Inc.     

Dielectrophoretic assay of bacterial resistance to antibiotics

The dielectrophoretic collection spectra of antibiotic-sensitive and antibiotic-resistant strains of Staphylococcus epidermidis have been determined. These indicate that in the absence of antibiotic treatment there is a strong similarity between the dielectric properties of sensitive and resistant strains, and that there is a significant difference between the sensitive strains before and after treatment with the antibiotic streptomycin after 24 h exposure. This method offers possibilities for the assessment of bacterial resistance to antibiotics.