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191.
Molecular cloning of bovine adrenal medulla (AM) and pituitary (Pit) alpha 1-antichymotrypsin cDNAs indicated novel isoforms of ACT. The deduced primary sequences indicated that the AM ACT and Pit ACT possess COOH-terminal reactive-site domains that are characteristic of serpins (serine protease inhibitors). Of high interest was the finding of unique reactive sites within AM ACT and Pit ACT which are predicted to possess Arg as P1 residue. Arginine as P1 residue parallels the cleavage specificity of neuroendocrine prohormone processing enzymes cleaving at basic residues. Furthermore, RT-PCR indicated tissue-specific expression of AM and Pit ACT mRNAs. The AM and Pit isoforms of ACT may regulate novel target proteases involved in neuroendocrine function. 相似文献
192.
Experimental evidence suggests a pathogenetic role for lipids in focal glomerulosclerosis (FGS) analogous to atherosclerosis. As foam cells (FC) are an important factor in atherosclerosis, a retrospective comparative study was done to evaluate the significance of intraglomerular FC in human FGS. Glomerular FC infiltration was evaluated in 115 biopsies of FGS, 120 biopsies of membranous glomerulonephritis (MGN) and 50 biopsies of minimal-change disease (MCD). Selected clinical and laboratory data collected at about the time of biopsy were reviewed. The proportion of biopsies showing glomerular FC was much higher in FGS (70%) than in either MGN (12%) or MCD (0%) p less than 0.001. The mean percent (+/- SD) of glomeruli with FC per biopsy was significantly greater in FGS (7.9 +/- 9.9) than in MGN (2.0 +/- 7.8; p less than 0.0001). Of the 14 MGN biopsies with FC, 13 showed superimposed FGS. Mean serum total cholesterol and triglyceride were not significantly higher in FGS than in either MGN or MCD. The results demonstrate a close association of glomerular FC infiltration with FGS. 相似文献
193.
T Valerius B Stockmeyer AB van Spriel RF Graziano IE van den Herik-Oudijk R Repp YM Deo J Lund JR Kalden M Gramatzki JG van de Winkel 《Canadian Metallurgical Quarterly》1997,90(11):4485-4492
Promising results from clinical trials with unconjugated antibodies stimulated renewed interest in immune effector mechanisms of monoclonal antibodies (MoAbs). We investigated the potential of IgA as antibody isotype for cell- or complement-mediated tumor cell lysis and assessed the potential of its myeloid Fc receptor, FcalphaRI (CD89), as trigger molecule for bispecific antibody (BsAb)-mediated immunotherapy. Comparing hapten-directed antibodies of human IgA2 with IgG1 or IgG3 isotypes, we found all three to mediate effective killing of sensitized tumor target cells in whole blood assays. Analysis of effector mechanisms showed IgG-mediated lysis to be predominantly complement-dependent, whereas IgA-dependent killing was primarily effector cell-mediated. A comparison of effector cell populations in antibody-dependent cell-mediated cytotoxicity (ADCC) showed neutrophils to be most important for IgA-dependent tumor cell killing, involving FcalphaRI as shown with Fc receptor blocking antibodies. Reverse ADCC experiments against target cells sensitized with Fc receptor antibodies, or assays with FcalphaRI-directed bispecific antibodies confirmed FcalphaRI as effective trigger molecule in polymorphonuclear neutrophil (PMN)-mediated lysis. During granulocyte colony-stimulating factor (G-CSF ) therapy, (FcalphaRI x HER-2/neu) bispecific antibodies induced enhanced killing of HER-2/neu positive SK-BR-3 breast cancer cells in whole blood assays. This enhanced cytotoxicity was paralleled by increased PMN counts, which lead to higher effector to target cell ratios in G-CSF-primed blood. Furthermore, bispecific antibodies, directed to FcalphaRI and Candida albicans, enhanced neutrophils' phagocytosis of fungi. In summary, these results identify IgA as an effective antibody isotype for immunotherapy, working primarily via FcalphaRI on neutrophils. They suggest FcalphaRI-directed bispecific antibodies and G-CSF to be an attractive combination for malignant or infectious diseases. 相似文献
194.
EI Nikolaeva EA Oteva VP Leutin AB Maslennikov LP Osipova AA Nikolaeva 《Canadian Metallurgical Quarterly》1995,52(3):207-211
In neonates and infants, hearing impairment leads to impaired language and cognitive development. For that reason, early detection of this sensory deficit is of outstanding importance, particularly in pre-term neonates, who constitute a high risk population in regard to very early acquired hearing loss. Evoked (EOAE) and spontaneous otoacoustic emission (SOAE) recording in 93 pre-term and full-term neonates revealed that this technique is potentially useful for auditory screening in neonatology units. EOAEs and SOAEs can be recorded successfully from 30 weeks of conceptional age. SOAEs were found to be prevalent in females and presented higher peak numbers in right than in left ears. Furthermore, SOAE incidence in pre-term and full-term neonates was found to be high in EOAE positive ears, associated with strong and robust EOAEs. 相似文献
195.
A method is described for the densitometric determination of the p-hydroxybenzoic esters and p-hydroxybenzoic acid in mixtures or in drugs. This method is compared with the one used in high performance liquid chromatography (HPLC). The calibration curves were linear in interval 0.250-3.60 mumol ml-1 per 200 nl per spot. The limit of detection and the relative standard deviation (RSD) are higher than in HPLC (RSD is 6% in HPTLC. 3% in HPLC; limit of detection about 40 pmol in HPTLC and 25 pmol in HPLC) but HPTLC quantitative determination of parabens in drugs is faster. 相似文献
196.
PL Dahia J Honegger M Reincke RA Jacobs A Mirtella R Fahlbusch GM Besser SL Chew AB Grossman 《Canadian Metallurgical Quarterly》1997,82(4):1088-1093
The molecular basis of Cushing's disease is not known. One of the most characteristic features of such tumors is their resistance to corticosteroid feedback at the pituitary level. We have hypothesized that abnormalities of the glucocorticoid receptor (GR) gene might play a role in the development of Cushing's disease via an increase in the relative production of the nonligand-binding splice variant of the GR, GR beta, known to exert dominant negative effects over the ligand-binding isoform, GR alpha. Alternatively, a change in overall GR expression, or mutations of some functional domains of the GR gene, might be involved in the pathogenesis of corticotroph tumors. We studied 22 tumors (17 pituitary ACTH-secreting tumors, 2 ectopic ACTH-producing tumors, 2 prolactinomas, and 1 nonfunctioning adenoma) and three normal pituitaries. RT-PCR was performed with primers specific to GR alpha and GR beta complementary DNA, followed by Southern blotting using an internal probe, and the ratio of the two bands quantitated by densitometry. We also assessed the overall expression of GR relative to the message of both the POMC gene and a housekeeping gene. Single-strand conformation polymorphism analysis of the DNA-binding domain and splice junction region of the gene was also performed. GR alpha messenger RNA was expressed at 37.3-fold +/- 5.7 (range, 32 to 46) excess, as compared with the GR beta subform. This pattern was observed both in the tumor samples and in the normal pituitaries used as controls. A majority of the ACTH-secreting tumors (16/19), including the ectopic secretors, showed variable but increased overall GR expression, whereas 3 tumors showed an expression approximately equivalent to the normal controls; however, no correlation was found between these two groups and the response to the high-dose dexamethasone test, nor was there any correlation with tumor histology. No mutations were found in any of the tumors by PCR-single-strand conformation polymorphism analysis. In conclusion, although both pituitary and ectopic ACTH-secreting tumors are at least partially glucocorticoid-resistant, no significant abnormalities in the relative expression of the two main GR subforms were observed in a series of such tumors. Additionally, mutations of regions critical to normal function of the receptor do not seem to be a frequent event in these tumors. 相似文献
197.
Heterotopic brain tissue, except in the head and neck region, is exceedingly rare. Mature neural tissue unexpectedly found in the subcutaneous tissues of the back of a toddler lacked an attachment to the central nervous system (CNS), and appeared to be unorganized glial tissue on pathologic evaluation. Appropriate clinical management of such lesions includes a suspicion of subcutaneous lesions near the CNS and evaluation to eliminate the presence of communication with the CNS, followed by surgical excision. 相似文献
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200.
Spatio-temporal coding in complex media for optimum beamforming: the iterative time-reversal approach 总被引:1,自引:0,他引:1
Montaldo G Aubry JF Tanter M Fink M 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》2005,52(2):220-230
Spatio-temporal encoding in transmit and receive modes is of major importance in the development of ultrasound imaging devices. Classically, the assumption of constant sound speed in the medium allows one to restrict the beamforming process to the application of a cylindrical time-delay law on the elements of a multiple-transducer array. Here is proposed an iterative time-reversal method capable of taking into account all the heterogeneities of the medium, concerning density, speed of sound, and absorption variations. It will be shown that this iterative focusing process converges toward a spatio-temporal inverse filter focusing, the first step of the process being a time-reversal focusing on the targeted point. This method can be seen as a calibration process and has been successfully applied to transskull focusing and intraplate echoes suppression. It is leading the way to promising applications such as high-resolution ultrasonic brain imaging and high-resolution focusing through complex reverberating media, in nondestructive testing and telecommunications. This work highlights the advantages of using spatio-temporal coding to focus through complex media. Such codes require the use of fully programmable, multichannel electronics to implement this technique in real time. 相似文献