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991.
Franciszek Burdan Zofia Siezieniewska Ryszard Maciejewski Barbara Madej Elzbieta Radzikowska Zbigniew Wojtowicz 《Experimental and toxicologic pathology》2002,53(6):453-459
The aim of the study was to establish the influence of short-time omeprazole administration on liver function and morphology. Omeprazole was administered intraperitoneally, twice daily, for 3 days to male Wistar rats in two doses: 0.571 mg/kg and 5.71 mg/kg. Control animals were treated with physiological saline. Half of the animals were sacrificed 12 hours after the last injection. The remaining rats were raised for another 6 weeks, without any xenobiotics, and sacrificed on the 47th day of the experiment. The activity of free and bound fractions of hepatic acid phosphatase, beta-galactosidase, beta-N-acetyl-glucosaminidase, cathepsin B, D and L, lipase, and sulphatase were determined spectrophotometrically in homogenates of the liver. The liver sections were examined by light microscopy with hematoxylin-eosin, azan, and periodic acid-Schiff stains. Marginally significant (p < 0.1) differences in activity of free sulphatase fraction, and free and bound fractions of beta-galactosidase were found in animals exposed to the higher dose of omeprazole and sacrificed 12 hours after the last injection. Enzymatic profiles were normalised during the next 6 weeks. Histological evaluation revealed small degenerative and adaptive changes in all examined groups. It could be concluded that observed differences of hepatic lysosomal enzyme activities were the result of accompanied chemical-induced peritonitis as previously reported, and not a direct drug-toxic effect. 相似文献
992.
We have developed a Joint Photographic Experts Group (JPEG) compatible image compression scheme tailored to the compression of digitized mammographic images. This includes a preprocessing step that segments the tissue area from the background, replaces the background pixels with a constant value, and applies a noise-removal filter to the tissue area. The process was tested by performing a just-noticeable difference (JND) study to determine the relationship between compression ratio and a reader's ability to discriminate between compressed and noncompressed versions of digitized mammograms. We found that at compression ratios of 15∶1 and below, image-processing experts are unable to detect a difference, whereas at ratios of 60∶1 and above they can identify the compressed image nearly 100% of the time. The performance of less specialized viewers was significantly lower because these viewers seemed to have difficulty in differentiating between artifact and real information at the lower and middle compression ratios. This preliminary study suggests that digitized mammograms are very amenable to compression by techniques compatible with the JPEG standard. However, this study was not designed to address the efficacy of image compression process for mammography, but is a necessary first step in optimizing the compression in anticipation of more elaborate reader performance (ROC) studies. 相似文献
993.
Core biopsies of the bone marrow are indispensable in the evaluation of fever of unknown etiology in human immunodeficiency virus-positive patients. We report two patients in whom visceral leishmaniasis was diagnosed based on the typical morphology, staining characteristics, and ultrastructure of the organisms. 相似文献
994.
The role of the complement system in innate immunity 总被引:4,自引:0,他引:4
Complement is a major component of innate immune system involved in defending against all the foreign pathogens through complement
fragments that participate in opsonization, chemotaxis, and activation of leukocytes and through cytolysis by C5b-9 membrane
attack complex. Bacterias and viruses have adapted in various ways to escape the complement activation, and they take advantage
of the complement system by using the host complement receptors to infect various cells. Complement activation also participates
in clearance of apoptotic cells and immune, complexes. Moreover at sublytic dose, C5b-9 was shown to promote cell survival.
Recently it was also recognized that complement plays a key role in adaptive immunity by modulating and modifying the T cell
responses. All these data suggest that complement activation constitutes a critical link between the innate and acquired immune
responses. 相似文献
995.
Bekiesińska-Figatowska M Chrzanowska KH Jurkiewicz E Wakulińska A Rysiewskis H Gładkowska-Dura M Walecki J 《Acta neurobiologiae experimentalis》2004,64(4):503-509
The results of brain MRI are presented in 22 patients with documented Nijmegen breakage syndrome (NBS), aged from 1 and 9/12 to 20 years. T1-, PD or FLAIR and T2-weighted SE/TSE images in three planes were obtained. Twenty-one patients showed microcephaly. Decreased size of frontal lobes and narrow frontal horns of the lateral ventricles was observed in all cases. In 6 patients agenesis of the posterior part of the corpus callosum was found as well as colpocephaly and temporal horn dilatation. In 2 patients callosal hypoplasia was accompanied by other anomalies: abnormal cerebrospinal fluid spaces. Sinusitis was present in all patients as a result of primary immunodeficiency. As in ataxia teleangiectasia and other breakage syndromes, NBS patients show inherited malignancy susceptibility and hypersensitivity to X and gamma radiation. Because of that computed tomography is contraindicated in these patients and MRI should be the method of choice in diagnostic imaging. 相似文献
996.
Michael Z. Gilcrease MD PhD Laura Schmidt PhD Berton Zbar MD Luan Truong MD Michael Rutledge MD Thomas M. Wheeler MD 《Human pathology》1995,26(12)
Papillary cystadenoma of the epididymis is an uncommon benign lesion that may occur sporadically or as a manifestation of von Hippel—Lindau (VHL) disease. Neither immunohistochemical studies nor molecular genetic analyses of the VHL gene have been reported previously for this lesion. The authors describe two cases of clear cell papillary cystadenoma of the epididymis, both of which were initially confused with metastatic renal cell carcinoma. Both lesions showed positive immunohistochemical staining for low and intermediate molecular weight keratins (Cam 5.2 and AE1/AE3), EMA, vimentin, α1-antitrypsin, and α1-antichymotrypsin. Each was negative for CEA. Because clear cell papillary cystadenoma is similar to renal cell carcinoma histologically, and because both occur as components of the von Hippel—Lindau disease complex, the authors analyzed both cases for the presence of mutations in the VHL gene. A somatic VHL gene mutation was detected in one of the two tumors by polymerase chain reaction followed by single-strand conformation polymorphism analysis. Direct sequencing revealed a cytosine to thymine transition at nucleotide 694, resulting in the replacement of an arginine with a stop codon after the sixth amino acid of exon 3. As the VHL gene is believed to function as a tumor suppressor gene, VHL gene mutations may play a role in the initiation of tumorigenesis in sporadic cystadenomas of the epididymis. 相似文献
997.
998.
Kanabus M Szelag E Kolodziejczyk I Szuchnik J 《Acta neurobiologiae experimentalis》2004,64(3):395-402
The temporal reproduction of standard durations ranging from 1 to 9 seconds was investigated in monochannel cochlear implant (CI) users and in normally hearing subjects for the auditory and visual modality. The results showed that the pattern of performance in patients depended on their level of auditory comprehension. Results for CI users, who displayed relatively good auditory comprehension, did not differ from that of normally hearing subjects for both modalities. Patients with poor auditory comprehension significantly overestimated shorter auditory standards (1, 1.5 and 2.5 s), compared to both patients with good comprehension and controls. For the visual modality the between-group comparisons were not significant. These deficits in the reproduction of auditory standards were explained in accordance with both the attentional-gate model and the role of working memory in prospective time judgment. The impairments described above can influence the functioning of the temporal integration mechanism that is crucial for auditory speech comprehension on the level of words and phrases. We postulate that the deficits in time reproduction of short standards may be one of the possible reasons for poor speech understanding in monochannel CI users. 相似文献
999.
Donangelo I Marcos HP Araújo PB Marcondes J Filho PN Gadelha M Chimelli L 《Endocrine pathology》2005,16(1):53-62
The retinoblastoma gene (RB1) is a tumor-suppressor gene in chromosomal region 13q14.2. Its role in the pathogenesis of pituitary tumors has not been
fully clarified. Some studies have shown that losses in this chromosomal region are related to aggressive tumor behavior,
although the retinoblastoma protein (pRB) is still expressed. Conversely, lack of expression of pRB was observed in one fourth
of GH-secreting pituitary adenomas (GH-tumors). In order to further study the expression of pRB in GH-tumors, we evaluated
this protein in 49 tumors from patients with acromegaly (20 noninvasive, 25 invasive, and 4 with no information) and 8 normal
pituitaries using immunohistochemistry (IHC). Nuclear staining for pRB ranged from 0 to 90% (median 40%) in the tumors and
from 40 to 80% (median 58%) in normal pituitaries. In 10 tumors (20% of total) the adenomatous cells were negative (5 cases)
or had very low labeling (5 cases) for pRB. Sixty three percent (31/49) of the tumors showed staining in 10–80% of the cells
and in 16% (8/49) of the cases >80% of the adenomatous cells were positive for pRB. The expression of pRB was not different
in invasive and noninvasive tumors. In conclusion, pRB is underexpressed in a subgroup of GH-tumors, and this may represent
an early event in the pathogenesis of this tumor subtype. 相似文献
1000.
Retinoblastoma and p53 gene product expression in breast carcinoma: Immunohistochemical analysis and clinicopathologic correlation 总被引:9,自引:0,他引:9
Michel Trudel MD Lois Mulligan PhD Webster Cavenee PhD Richard Margolese MD Jean Ct MD Gilles Garipy MD 《Human pathology》1992,23(12):1388-1394
We examined 100 breast cancers for retinoblastoma (Rb) and p53 protein expression by immunohistochemistry using the PMG3.245 and PAb 1801 antibodies. We assessed percentages of reactive cells and their intensity, as well as staining patterns. The results were correlated with neu protein reactivity and a panel of variables, including age, tumor size and type, nuclear grade, estrogen receptor/progesterone receptor content, and lymph node status. Retinoblastoma protein negativity, either partial or complete, was noted in 47% of cases. Surprisingly, a relatively stronger Rb reaction was seen in some high nuclear grade tumors. p53 positivity was found in 23% of cases and was a significant predictor of Rb loss. p53 also was correlated with poorly differentiated (nuclear grade III) neoplasms and neu expression but not with negative ER status. Tissue distribution profiles for Rb-negative and p53-positive cells were variable in this series, with both uniform and heterogeneous patterns observed. This suggests that Rb and p53 alterations may represent early or late events in transformation. Our findings further implicate Rb and p53 derangements in mammary oncogenesis. 相似文献