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51.
Mesangial cells of the renal glomerulus are thought to have contractile properties, resembling those of smooth muscle cells. Since actin synthesis in mesangial cells is increased in selected animal models of glomerulonephritis, we evaluated the expression of alpha-smooth muscle actin (ASMA), the principal actin isoform found in smooth muscle cells, in biopsy specimens from patients with primary glomerular disorders and in control tissues. Normal glomeruli and glomeruli in acute tubulointerstitial disorders showed few or no ASMA-positive cells in the glomeruli. In contrast, ASMA expression in mesangial cells was increased in minimal change disease, focal segmental glomerulosclerosis, mesangial proliferative glomerulonephritis, membranous glomerulonephritis, and immunoglobulin A nephropathy. In membranoproliferative glomerulonephritis and cryoglobulinemic glomerulonephritis both mesangial and capillary loop ASMA-positive cells were observed with a segmental distribution. In addition, ASMA-positive interstitial cells were seen in many biopsy specimens and often were increased in number in biopsy specimens showing early interstitial fibrosis and tubular atrophy. We conclude that ASMA synthesis in mesangial cells is upregulated in a variety of glomerular disorders, frequently associated with increased cell proliferation and mesangial matrix production. This phenotypic change may be an indicator of mesangial cell activation after injury and may have important pathophysiologic consequences. 相似文献
52.
CL Finstad KO Lloyd MG Federici C Divgi E Venkatraman RR Barakat RD Finn SM Larson WJ Hoskins JL Humm 《Canadian Metallurgical Quarterly》1997,3(8):1433-1442
Our objective was to quantify the targeting of the monoclonal antibody (mAb) MX35 F(ab')2 to micrometastatic epithelial ovarian cancer. This mAb detects a Mr 95,000 glycoprotein with homogeneous distribution on 80% of ovarian tumor specimens. Six patients with minimal residual disease from an imaging trial were injected with 2 or 10 mg of 131I- and 125I-labeled mAb MX35 F(ab')2. Biopsied samples were removed at second-look laparotomy 1-5 days post-i.v. or -i.p. infusion of antibody. Serial cryostat sections were stained by indirect immunoperoxidase method for antigen distribution and exposed to storage phosphor screens for quantitative autoradiography. Coregistration of tumor histology, antigen expression, and radionuclide distribution demonstrated specific localization in micrometastatic tumor foci (50 micrometer to 1 mm) found within tissue stroma. The radiolabeled antibody uptake determined by well scintillation counts ranged between 5.2 and 223.5 x 10(-4) percentage of injected dose/g of tumor tissue for 131I. Specific localization of mAb in tumor was determined by tumor:normal tissue (fat) ratios ranging from 0.9:1 to 35.9:1 for 131I. The high resolution and linear response of the storage phosphor screen imager was used to estimate the radionuclide activity localized in each micrometastatic site. Quantitation of phosphor screen response revealed microCi/g values of 0.026-0.341 for normal tissue and 0.184-6.092 for tumor biopsies, evaluated 4 or 5 days post-antibody injection. The tumor:normal tissue (adjacent to tumor) ratios were between 1 and 4 times greater using the phosphor screen method than well counter measurements, but even larger variations of ratios up to 20:1 were observed between tumor cell foci and stromal cells within the same tissue section. This study has demonstrated that mAb MX35 F(ab')2 localizes to the micrometastatic ovarian carcinoma deposits within the peritoneal cavity. The dosimetry results suggest a therapeutic potential for this antibody in patients with minimal residual disease (<5 mm). 相似文献
53.
M Ui D Endoh KO Cho Y Kon A Iwata Y Maki F Sato M Kuwabara 《Canadian Metallurgical Quarterly》1998,60(7):823-829
Prevention of the occurrence of diabetes-specific vascular complications is the final aim of clinical islet transplantation. Pancreatic islets isolated from adult pigs may be a suitable tissue source to transplant a large number of type 1 diabetic patients. Acute cellular rejection may be finally overcome by clinically applicable protocols for tolerance induction. However, primary nonfunction of the graft, as regularly observed in the porcine islet-to-rat xenotransplantation model, may be an additional problem. In this paper, species-specific inflammatory and immunological mechanisms are discussed which prevent early porcine islet graft function in rats but not in mice. 相似文献
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Irreversible conversion of xanthine dehydrogenase (XDH) to its oxygen free radical producing oxidase (XO) form occurs through an uncharacterized proteolytic process, which was studied in human liver. Upon incubation of fresh unfrozen liver cytosol, XDH remained intact. When recombinant human XDH was coincubated with subcellular fractions of human liver, the mitochondrial intermembrane space was shown to contain a heat-labile activity that converted XDH irreversibly to XO. This activity is resistant to inhibitors of all major groups of proteases. We postulate that this novel type of proteolytic enzyme is released into the cytosol upon mitochondrial damage. 相似文献
57.
To clean the exhaust emissions as one of the most important tasks in pollution control, a study on the treatment of engine emissions with discharge assistance was reported. A DBD plasma source shaped in grid and cylinder was examined in different engine operational modes to reduce the NOX content of diesel engine exhaust. The composition of the exhaust gases and chemical reactions initiated by the discharge were analyzed. The discharge frequency had a crucial impact on the device’s performance and gas treatment. The voltages applied to the discharge gap could alter the chemical reactions occurring in the treated gases, which were indicated by the NO to NO2 ratio. The operation of the system was studied at frequencies ranging from 400 Hz to 16 kHz. 相似文献
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ABDELLATIF A. MOHAMED SHERALD H. GORDON CRAIG J. CARRIERE SANGHOON KIM 《Journal of food quality》2006,29(3):266-281
The interaction between polylactic acid (PLA) and wheat gluten (gluten) has been studied using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), Fourier transform infrared (FTIR) spectroscopy, X‐ray diffraction and phase contrast microscope. The primary DSC thermogram of gluten showed one glass transition (Tg) at 63C. Neat (pure) PLA also showed a Tg around the same temperature range followed by crystallization (Cry) and a melting (Mel) transition. Different PLA : gluten blends (20:80, 50:50, 80:20) showed a Tg followed by PLA Cry and immediate Mel transitions. However, subsequent heating‐cooling cycling of the blend demonstrated a decrease in PLA Cry and Mel transitions and the appearance of a second Tg. The presence of gluten reduced the number of cycles needed to change PLA Cry structure to mostly amorphous. The low PLA Cry indicates an interaction between the two polymers. The TGA data showed slower PLA degradation compared with gluten, where 10% was degraded at 316C while 10% of the gluten degraded at 254C. Solid‐state FTIR showed that amide I and II peaks significantly decreased signifying gluten‐heat degradation. A strong peak, corresponding to ester formation between gluten and hydrolyzed gluten molecules, appeared at 1750/cm. The esterification increased in the presence of PLA. The phase contrast microscope demonstrated that the melting of PLA starts at 150C, which means that the continuous phase between 150 and 250C was the melted PLA. At 220C, gluten formed a thin layer; and at about 245C, it aggregated. 相似文献
60.
Nelson KO Ojijo Ishak Neeman Shaul Eger Eyal Shimoni 《Journal of the science of food and agriculture》2004,84(12):1585-1593
Functionality of conventional fat spreads can be achieved without hydrogenation by the formation of stable network structures upon cooling of mixtures of monoglycerides (MGs) and vegetable oils from the melt. Such mixtures are healthy substitutes for margarine and butter. The effects of MG content, cooling rate and shear on the temperature ramp, mechanical spectra and hardness of olive oil/MG gel networks were investigated. A minimum MG volume fraction was necessary for formation of a gelled network, but this concentration was less than that needed for a space‐filling network structure. Onset of gel network or structure formation was indicated by a sudden divergence in value of the elastic modulus G′. The temperature at onset of structure formation, To, final G′ value and network hardness all increased with increase in MG content. High cooling rates led to low final G′ values but harder networks, and vice versa. Maximum gel network development occurred when moderate shear (about 300 s?1) was applied at incipient gelation. Copyright © 2004 Society of Chemical Industry 相似文献