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971.
972.
AC Nicholls 《Canadian Metallurgical Quarterly》1977,2(6078):46-47
973.
A new technique, sputter-initiated resonance ionization spectroscopy (SIRIS), which provides an ultrasensitive analysis of solid samples for all elements except helium and neon is described in this paper. Sensitives down to 1 part in 1012 should be available in routine SIRIS analysis, and greater sensitivities should be available for special cases.The basic concepts of this technology and early results in the development of the new SIRIS process and apparatus are presented. 相似文献
974.
Platelets contain heparin neutralizing activity, which is released into plasma following aggregation. This material is probably identical to platelet factor 4. We describe a technic to measure heparin neutralizing activity in platelet-poor plasma based on the serial heparin dilution technic of Harada and Zucker. Heparin neutralizing activity was depressed in thrombocytopenia due to immune thrombocytopenia and bone marrow depression, and elevated in thrombocytopenia due to disseminated intravascular coagulation. Secondary thrombocytosis is characterized by markedly elevated heparin neutralizing activity, while thrombocytosis associated with myeloproliferative disorders has normal heparin neutralizing activity. 相似文献
975.
Gpx2 mRNA, encoding a selenium-dependent glutathione peroxidase (GPX-GI), has been found to be highly expressed in the gastrointestinal tract (GI) mucosal epithelium. In this study, we show that GPX-GI is produced in the mucosal epithelium of the adult rat GI tract and that the activity levels are comparable to that from GPX-1. Post-mitochondrial supernatant GPX activity from the mucosal epithelium of the complete length of the small intestine was partially purified. A sample enriched for putative GPX-GI was fractionated by SDS-polyacrylamide gel electrophoresis. Polypeptides of 21 kDa and 22 kDa were digested with trypsin. After resolving the tryptic peptides by high pressure liquid chromatography (HPLC), the major peaks were analyzed for their amino acid sequence by Microflow-HPLC-Tandem Mass Spectrometry and automated Edman degradation sequencing. Both methods revealed that the 21-kDa sample contained rat GPX-GI determined by the sequence homology with the deduced mouse GPX-GI polypeptide sequence. Rat GPX-1 was also detected in the samples. AntiGPX-GI and antiGPX-1 antibodies were used to determine the distribution of the respective isoenzyme activities along the length of the intestine and with respect to the crypt to villus axis in rats. GPX-GI and GPX-1 activities were uniformly distributed in the middle and lower GI tract and with respect to the crypt to villus axis. GPX-GI activity accounted nearly the same percentage of the total GPX activity as GPX-1 in all of the these compartments. Studies on the distal ileum segment of wildtype and Gpx1 gene knockout mice showed that GPX-GI activity was also at parity with GPX-1 in the mucosal epithelium of this segment. 相似文献
976.
SO Ibrahim B Bertelsen MB Kalvenes AM Idris EN Vasstrand R Nilsen AC Johannessen 《Canadian Metallurgical Quarterly》1998,106(10):959-969
In stratified squamous epithelia, altered expression of keratins (Ks) is one possible marker of malignant potential. In the epithelium of the uterine cervix, presence of human papillomaviruses (HPVs) is increasingly regarded as a marker of risk for cervical cancer. However, a similar role in oral cancer and precancer remains controversial. To address these questions, formalin-fixed, paraffin-embedded oral carcinomas from Sudanese snuff dippers (n=14) and oral carcinomas from Sudanese (n=14), Swedish (n=19) and Norwegian (n=41) non-snuff dippers were examined by immunohistochemistry for expression of K types 13, 14 and 19 using monoclonal antibodies. HPV infection was searched for in all the carcinomas by in situ hybridization (ISH) using the cocktail HPV OmniProbe and the ViraType probe. Carcinomas from Sudanese (snuff dippers/non-snuff dippers) were also examined for HPV infection by polymerase chain reaction (PCR) using the general HPV primers GP5+/GP6+. For the oral carcinomas from snuff dippers, moderate to intense expression of K13 (71%; 10/14), K14 (86%; 12/14) and K19 (93%; 13/14) was found. For the oral carcinomas from non-snuff dippers, weak to moderate expression of K13 (64%; 47/74), K14 (43%; 32/74) and K19 (45%; 33/74) was found. HPV DNA was not detected in any of the carcinomas from three countries when examined by ISH. The Sudanese (from snuff dippers/non-snuff dippers) oral carcinomas were also negative for HPV DNA with the PCR. The present study shows that (i) there is a high level of expression of K13, K14 and K19 in oral carcinomas from snuff dippers compared to those from non-snuff dippers, (ii) this high level of expression may arise from dysregulation of keratinocyte proliferation and maturation caused by damaging effects of snuff, (iii) the HPV genome is not found in Sudanese (snuff dippers/non-snuff dippers), Swedish or Norwegian oral carcinomas, and (iv) this may suggest that these viruses do not play a prominent role in the aetiology of oral carcinomas from these countries. 相似文献
977.
S Pagliarini A Moramarco RP Wormald B Piguet C Carresi C Balacco-Gabrieli KS Sehmi AC Bird 《Canadian Metallurgical Quarterly》1997,115(5):616-622
OBJECTIVE: To report the prevalence of age-related maculopathy (ARM) in Salandra, a small, isolated southern Italian community, to test the hypothesis that an environmental factor, scarce in such a remote community but ubiquitous in modern industrial societies, might modify the risk of developing ARM. DESIGN: Population-based cross-sectional survey. MAIN OUTCOME MEASURES: Prevalence of advanced age-related macular degeneration (ARMD) (geographic atrophy or exudative maculopathy) and ARM (large, soft drusen or retinal pigment epithelium changes, or both) defined by fundus biomicroscopy and 30 degrees stereoscopic, macular photography. Self-sustenance was assessed by interview of participants and local shop retailers. The degree of genetic isolation was computed using a model that fits the genetic population structure with the frequency distribution of surnames in the community. RESULTS: A full ophthalmic examination was undertaken in 366 (63.5%) of 576 eligible participants, 354 (96.7%) of whom had clinical or photographic assessment for the presence of ARMD and 310 (84.6%) of whom had drusen characteristics graded on color transparencies for ARM. The overall prevalence of ARMD was 1.1%. Drusen larger than 50 microns and more numerous than 10 were found in 4.5% of subjects. Salandra was the birthplace of 87.2% of participants and for 77.3% of both parents of each subject. People in the community tended to consume homegrown products. CONCLUSION: The prevalence of ARM may be lower in this self-sustained farming community than elsewhere in the industrialized world. 相似文献
978.
Large cell change (LCC), characterized by cellular enlargement, nuclear pleomorphism and hyperchromasia, and multinucleation of hepatocytes, is a common lesion in cirrhotic livers, but its nature, significance, and pathogenesis remain uncertain. Therefore, we assessed the prognostic value of LCC as a marker of subsequent hepatocellular carcinoma (HCC) through a case-control study that compared pretransplant liver biopsy specimens from 37 cirrhotic liver transplant recipients with HCC to specimens from a control group of recipients without HCC, matched for sex, age (+/-5 years), and cause of cirrhosis. LCC was identified in 16 (43%) of the study and 7 (19%) of the control group biopsy specimens. By matched-pair analysis, LCC conveyed a moderately increased risk of later HCC with an estimated odds ratio of 3.3 (95% CI, 1.2-15; P = .038). However, a pathology review of 45 HCCs showed adjoining LCC in only 12 (27%) and did not suggest a morphological transition or a histogenetic association between the two lesions. LCC hepatocytes displayed a low proliferative rate by Ki-67 or proliferating cell nuclear antigen immunostaining (labeling indices of 0.27 and 0.73) but showed a greater degree of apoptosis than normal hepatocytes (labeling indices of 1.9 and 0.23; P = .03) To reconcile these findings, we propose that LCC derives from derangements in the hepatocyte's normal process of polyploidization. Such derangements, possibly caused by chronic inflammation-induced DNA damage, could yield a population of enlarged liver cells with nuclear atypia and pleomorphism, frequent binuclearity, and minimal proliferation. According to this hypothesis, LCC would be a habitual feature of cirrhosis and a regular accompaniment of HCC but would not represent a direct malignant precursor. 相似文献
979.
Reducing physical abuse directed at women by male partners is one of the nation's Year 2000 health objectives. An important target group for achieving this health objective is pregnant women. The present study examines the frequency, severity, perpetrators and psychosocial correlates of violence during the childbearing year. A panel of 275 women were interviewed 3 times during pregnancy and at 6 months postpartum. Moderate or severe violence was somewhat more common during the postpartum period than during the prenatal period--19% of women reported experiencing moderate or severe violence prenatally, compared to 25% in the postpartum period. For partner-perpetrated violence, being better educated was associated with increased risk of violence as was having had a sex partner who ever shot drugs; being older, having a confidant and having social support from friends were significant protective factors. For violence perpetrated by someone other than a male partner, having a confidant was a significant protective factor. Obstetric care providers who routinely come in contact with pregnant women, as well as emergency department staff, need to be systematically screening for violence against women. Efforts to enhance women's social support networks should be included in primary and secondary prevention programs. 相似文献
980.
AC Bateman DA Sage RK Al-Talib JM Theaker DB Jones WM Howell 《Canadian Metallurgical Quarterly》1996,28(2):169-174
Topical application of 5-aminolevulinic acid (5-ALA), with subsequent synthesis of protoporphyrin IX (PPIX), is a novel outstanding procedure for photodynamic treatment. So far, clinical experience has been reported with creams containing 5-ALA for the therapy of skin cancer, oral application for the treatment of gastrointestinal disease and intravesical instillation of 5-ALA solutions for fluorescence detection of superficial bladder cancer. Inhalation of 5-ALA for the staining of bronchial malignancies is a preferred method in clinical pulmonology. Since no adverse reaction was observed in lung function in a canine following inhalation of 5-ALA in increasing concentrations, clinical applications were performed. Seven patients with positive or suspicious sputum cytology, but negative white light bronchoscopy, received 5-10 wt.% 5-ALA in NaCl solution by means of a medical nebulizer. No side effects were observed during and after 5-ALA inhalation. After a period of 3 h, patients underwent fluorescence bronchoscopy using violet light for fluorescence excitation and an optical multichannel analyzer for fluorescence detection in situ. The results showed fluorescence spectra which could be related to PPIX induced by 5-ALA in the bronchial mucosa. The fluorescence intensity was sufficiently high for video imaging using a target integrating color CCD camera adapted to the flexible bronchoscope. Carcinoma in situ, as well as dysplasias, showed a clear positive fluorescence. A correlation of fluorescence contrast with histology on 30 biopsies revealed a high sensitivity, but a specificity below 50%. Improvements in light and drug dosimetry will form the basis for further clinical trials. 相似文献