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31.
Image intensifier distortion correction   总被引:2,自引:0,他引:2  
A method is described for determining and correcting the spatial distortion affecting images acquired with image-intensified video systems. The distortion is separated into two physically distinct components, a predominant one originating from the projection of the x-ray image onto the curved input phosphor, and a smaller component corresponding to the mapping from the input phosphor to the output phosphor and the digital image matrix. The former is determined geometrically and the latter is modeled with four empirical parameters. A method for determining the two components from calibration images of a grid phantom is presented. The model of the image intensifier distortion was found to be in good agreement with the measured distortion in the images. The correction is applicable to arbitrary angulations of the x-ray beam with respect to the image intensifier tube, and consequently is directly applicable to digital tomosynthesis. The correction allows one to obtain accurate positional information with fluorography and may also be useful in radiation therapy treatment planning and quantitative digital subtraction angiography.  相似文献   
32.
A functional analysis of tumor-infiltrating lymphocytes (TILs) from renal cell carcinoma (RCC) and malignant melanoma was performed. TILs were expanded in recombinant interleukin-2 (50 U/ml) in Iscoves medium. Phenotypic and functional (cytolytic vs regulatory) analyses were carried out with the fresh and expanded TIL populations after 4 weeks in culture. Only one TIL population from an RCC case (out of six cases studied) was CD8+ and demonstrated MHC class I-restricted tumor-specific cytotoxicity against the autologous RCC target. TIL populations from the other five cases became predominantly CD4+ and they neither killed the respective autologous tumor cells nor killed the NK-sensitive target K-562 cells. When studied for other functions, two CD4+ TIL populations were found to suppress the lymphokine-activated killer cell response by peripheral blood lymphocytes (PBL) in coculture. Of these two, a TIL population from an RCC case (MJ TIL) was used to study the cellular and molecular mechanisms of suppression. The MJ TIL synthesized a supernatant factor that blocked activation of resting PBL as measured by the induction of high-affinity IL-2 receptor (IL-2R) when stimulated by phytohemagglutinin but did not down-regulate the fully expressed IL-2R on activated T cells. The suppression of high-affinity IL-2R induction on T cells did not result from tumor necrosis factor-alpha and beta or from transforming growth factor-beta as these cytokines were not detected in the cell-free supernatant from the MJ TIL culture. The supernatant factor also suppressed IL-2-mediated enhancement of cytotoxicity by natural killer (NK) cells without demonstrating direct toxic effect on the NK cells. Thus, when TIL are used for adoptive immunocytotherapy, it may be useful to fully characterize them functionally, in vitro.  相似文献   
33.
BACKGROUND: Verumontanum mucosal gland hyperplasia (VMGH) and atypical adenomatous hyperplasia (AAH) are both small glandular proliferations that are histologically and topographically unique. METHODS: One hundred ten randomly selected, whole-mount, radical prostatectomy specimens were reviewed to assess independently the normal histology of the prostatic urethra and periurethral area and the association of AAH with other pathologic features, including VMGH. The degree of nodular hyperplasia was evaluated by total prostate weight for comparison purposes. RESULTS: Atypical adenomatous hyperplasia was found in 37 cases (33.6%) and was nearly always (32/37) associated with nodules of nodular hyperplasia. Verumontanum mucosal gland hyperplasia was present in 32 cases (29.1%; 21 with AAH, 11 without AAH). There was a significant association between presence of VMGH and AAH (P <.001, Fisher exact test). The degree of nodular hyperplasia was not significantly different between prostates with and without VMGH or AAH. CONCLUSIONS: These results suggest that AAH and VMGH occur more commonly in prostates when the other is also present.  相似文献   
34.
The aim of the study was the characterization of Malassezia pachydermatis and its pigment-producing subgroup using biochemical tests and RAPD. It was of interest to determine whether particular RAPD patterns could be used to indicate pigment production, as well as a close genetic relatedness to Malassezia furfur. Therefore, 210 strains of M. pachydermatis were examined for morphology, catalase and ss-glucosidase activity, lipid and carbohydrate assimilation and the tryptophan-dependent synthesis of pigments. Of these, 114 strains were subjected to RAPD analyses. A multivariate logistic regression model was applied to classify M. pachydermatis isolates regarding their pigment production by using genetic and biological parameters. Biological and RAPD findings showed a high biological and genetic diversity within the species M. pachydermatis and within pigment producers. RAPD analysis revealed 28 genotypes within 114 strains tested. Pigment producing strains could not be assigned to a common RAPD profile, but a genetic relatedness of pigment-producing M. pachydermatis with M. furfur can be assumed. A particular RAPD pattern allowed statistically significant probability of pigment production (P<0.001) and might be used as a tool to rapidly detect pigment producing M. pachydermatis, e.g. in Malassezia-associated pityriasis versicolor. The reported method is useful for identification of pigment producing M. pachydermatis isolates and has advantages over established tests.  相似文献   
35.
Chronic tubulointerstitial injury (CTI) including tubular atrophy and interstitial fibrosis represents one major determinant for the progression of chronic renal disease regardless of cause. Although peritubular capillaries (PTCs) are essential to maintain the normal structure and function of renal tubules, little is known about the role of PTCs in the development of CTI. The integrity of PTCs seems to be regulated by growth factors. Vascular endothelial cell growth factor (VEGF) has recently been recognized as a potent regulator of angiogenesis, vascular survival, and vascular permeability. Knowledge of the role of VEGF in renal disease is still rudimentary, and its role in CTI has not been explored. We analyzed the morphologic changes of PTCs and correlated them with other morphologic parameters of CTI in 32 human kidneys with various types of chronic tubulointerstitial disease. The VEGF expression was immunohistochemically evaluated. Compared with normal kidney, PTC loss (41% to 55% of control) and reduced size of PTCs (55% to 88% of control) were noted in kidneys with CTI. The PTC density was positively correlated with the proximal tubular density (r = 0.66, P <.0001), proximal tubular size (r = 0.54, P <.001), and negatively correlated with interstitial volume (r = -0.84, P <.0001). Compared with normal kidney, where podocytes were the only cell type that constantly expressed VEGF, an interesting pattern of increased VEGF expression by renal tubules, especially morphologically intact or hypertrophic ones, was shared by all cases with CTI. Loss of VEGF in sclerotic glomeruli was noted. PTC injury is pathogenetically linked to tubular atrophy, tubular loss, and interstitial fibrosis in human kidneys with CTI and might be a key factor for the progression of chronic tubulointerstitial disease. The characteristic and uniform pattern of altered VEGF expression in kidneys with CTI may result from ischemia induced by PTC loss and represent a protective mechanism against further PTC injuries. HUM PATHOL 31:1491-1497.  相似文献   
36.
Upper and centralized body fat distribution is associated with non-insulin dependent diabetes mellitus (NIDDM). Few studies have focused on anthropometric characteristics of preadults from families in which there is a diabetic (NIDDM) proband. This study explores the prevalence of upper and centralized body fatness in Mexican American children from the Diabetes Alert study (1981–1983) in Starr County, Texas. Anthropometric data on 165 males and 224 females 9–19 years include measures of adiposity such as skinfold thicknesses and the body mass index (BMI), a measure of overweight. They show rates of obesity two to three times that of White children of comparable age and sex from National Health Surveys. In comparison with U.S. White subjects, Mexican American adults are shorter, have more adiposity and arm muscle mass and have sitting heights and body breadths at the mean of these dimensions for the U.S. population. Children from Diabetes Alert families show only marginal excess of severe obesity (> 95th percentile of BMI) when compared to the general population of children surveyed in Starr County schools. Girls from these families, but not boys, have excess fatness in the BMI compared to Mexican American children from the Hispanic Health and Nutrition Examination Survey (HHANES); suprailiac skinfold thicknesses are also greater in children of the Diabetes Alert study than in HHANES children. From 1972 through 1982, Mexican American children in South Texas showed an increase in average stature, weight, and the BMI. These data together suggest that excessive obesity exists and may be increasing in children in populations at risk for NIDDM. The prevention of NIDDM in the Mexican American population may be more effective if educational and promotional interventions include the school aged population. © 1993 Wiley-Liss, Inc.  相似文献   
37.
Cancer mortality in relatives of retinoblastoma patients   总被引:3,自引:0,他引:3  
The risk of other cancers in relatives of retinoblastoma (RTB) patients was determined by a survey of the mortality experience of siblings, parents, parental siblings, and grandparents of all U.S. or Canadian RTB patients referred to The University of Texas M.D. Anderson Hospital and Tumor Institute between 1944 and 1980. Expected mortality was ascertained by the application of age-, sex-, race-, and calendar year-specific U.S. mortality rates to the observed person-years. Among 607 relatives of 33 unilateral-sporadic RTB probands, no excess in cancer deaths was observed (observed/expected = 18/22). Among 733 relatives of 47 bilateral-familial RTB probands, a slight excess in cancer deaths was observed (41/31). A significant excess in cancer deaths was occurred in relatives under age 55 years (18/9) and in fathers (7/1) of the bilateral RTB probands. To determine whether the cancer excess was related to some unique allele associated with second tumors in RTB survivors, the cancer mortality of 203 relatives of the 14 RTB patients with second tumors was examined, and no excess was observed (11/11). To determine whether the excess might be attributable to an unexpressed RTB gene or precursor, the mortality experience was examined in 6 kindreds in which parents, unaffected by RTB, had more than 1 child with RTB. Among these 72 relatives a significant excess in cancer deaths was observed (8/2). The findings demonstrate a modest overall cancer excess in relatives of hereditary RTB patients and suggest it may be attributable to an unexpressed RTB gene or precursor in a small number of kindreds. Mechanisms for an apparent "precursor" might involve a delayed mutation, genetic mosaicism, or a submicroscopic balanced chromosomal translocation.  相似文献   
38.
BackgroundInjuries are a focus of public health practice because they pose a serious health threat and are preventable. Currently, injury accounts for 14% of all Disability Adjusted Life Years (DALYs) losses for the world''s entire population. In India, unintentional injuries within the home environment have not so far been recognized to the same extent as traffic and work-related injuries among all age groups. With this background, a community based epidemiological study was conducted with the aim to find out the prevalence and epidemiology of unintentional injuries.MethodsA cross-sectional study was conducted during July 2018 - June 2019 in Bhatar block of Purba Bardhaman District. Cluster random sampling was applied to select required sample of 555 individuals from 24 villages. The study tools used were a predesigned and pretested schedule developed by the researchers with the help of Guidelines for conducting community surveys on injuries by World Health Organization (WHO) and a checklist for assessing household level injury hazard. The study had approval from Institutional Ethics Committee. Chi square test and multivariable logistic regression were performed using SPSS V16.ResultsPrevalence of unintentional injury was 8.8 % in the preceding three months. Multivariable logistic regression revealed that those who were below 18 years of age, severely vulnerable to unintentional injuries and belonged to nuclear families had significantly higher odds of developing unintentional injuries at home.ConclusionUnintentional injury is prevalent in West Bengal. Dissemination of injury prevention information with special focus on household modification is an effective strategy to prevent unintentional injuries.  相似文献   
39.
Following crush injury to rat sciatic nerves, a crude fraction of the 150,000 g supernatant can post-translationally incorporate [3H]Arg and [3H]Lys into endogenous proteins in amounts approximately 10 times uninjured control nerves. These increases occur in the proximal nerve stump within 2 h of injury and 2 weeks later in a distal segment of nerve containing the tips of the regenerating axons. In the present experiments, the endogenous nerve proteins modified by Arg or Lys in these nerve segments have been identified using two-dimensional polyacrylamide gel electrophoresis. The fraction used to assay for protein modification, the void volume of a Sephacryl S-300 column, was found to contain only a few proteins visible by Coomassie blue staining, one of which is likely to be albumin (68 kDa, pI 6.4). While this protein was modified by both Arg and Lys, the majority of label was found in areas not showing Coomassie blue staining. This indicates that of the many potential targets of post-translational arginylation and lysylation, most are proteins of relatively low abundance. A variety of proteins were modified by Arg or Lys alone while others were modified by both Arg and Lys. A high molecular weight protein (175 kDa, pI 9.0) was modified only by Lys and only at 2 h post crush. Of a variety of modified proteins of approximately 17 kDa one (pI 6.3) was modified by both Arg and Lys and at both time points, while another (pI 9.0) was modified at both time points, but only by Lys. The results show that Arg and Lys can be added post-translationally to a large number of low abundance, soluble sciatic nerve proteins, and that some of those proteins are modified only by Arg or Lys while others are modified by both Arg and Lys. Also, the modification of certain proteins appears to be associated specifically with the immediate response of a nerve to injury (e.g. 88 kDa, pI 7.1) while others are associated with the regenerative period (e.g. 56 kDa, pI 7.4).  相似文献   
40.
Both axonal and glial components of nerve are capable of carrying out reactions in which Arg, Lys, Leu, Pro, Val, AJa and Ser can be covalently linked to endogenous proteins in reactions which require tRNA but occur in the absence of ribosomes and ribosomal RNA. These posttranslational protein modifications appear to play important roles in nerve regeneration since they are increased more than 10-fold within 2 h of a crush injury in nerves which are capable of regeneration, but are not activated in nerves not capable of regrowth following injury. The regulation of the modification of proteins by Arg and Lys in vivo appears to be the function of separate peptides. The exogenous application of serine protease inhibitors (but not other protease inhibitors) mimics the effect of the endogenous peptides, suggesting that the endogenous regulators have serine protease inhibitory activity. The targets for modification are proteins of low abundance and thus far have been identified only in terms of their molecular weights and isoelectric points. The site of addition of Arg, but not the other amino acids, to target proteins is to the amino terminus. The addition of Arg to an amino terminus is likely to be involved in the ubiquitin mediated proteolysis of the modified protein. One of the most unusual findings in these series of experiments is that in regenerating sciatic nerves, amino acid modified proteins aggregate to form complexes of greater than 2 × 106 Da. The significance of this finding is not known. But we speculate that the aggregate may result from the assembly of an insoluble functional unit of the cell from soluble precursor proteins, and that the trigger for their assembly is amino acid modification.  相似文献   
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