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Since the advent of CT, secondary neoplastic lesions of the kidneys have been detected with increasing frequency. After reviewing a large series of cases of renal metastases, we have been able to classify the CT findings into seven major categories that are discussed and illustrated in this article. The differential diagnoses between metastatic disease of the kidneys and other lesions such as renal infarctions, renal lymphoma, and primary malignancies are also considered.  相似文献   
3.
Telomerase reactivation is an early event in laryngeal carcinogenesis.   总被引:4,自引:0,他引:4  
The exact role and timing of reactivation of telomerase, a key enzyme implicated in cellular immortalization and transformation in the multistep process of laryngeal carcinogenesis, is still unknown. We attempted to (1) determine that quantitative differences exist in the levels of telomerase catalytic subunit (hTERT) mRNA expression among different grades of laryngeal epithelial abnormalities classified according to the Ljubljana classification; (2) determine that telomerase reactivation is an important, most probably early event in laryngeal carcinogenesis; and (3) analyze whether the relative quantity of hTERT mRNA can be used as a molecular biomarker in the early detection of precancerous lesions. The relative quantity of hTERT mRNA, expressed as an hTERT index, was analyzed in 140 frozen laryngeal tissue specimens representing different morphological stages of laryngeal carcinogenesis by using a commercially available LightCycler Telo TAGGG hTERT Quantification kit. The presence and relative quantity of hTERT mRNA in laryngeal epithelium increases progressively with the degree of epithelial abnormalities. hTERT mRNA was detectable in 1/15 normal laryngeal epithelia (7%, mean hTERT index 0.02), 3/15 simple hyperplasias (20%, mean hTERT index 0.09), 10/27 abnormal hyperplasias (37%, mean hTERT index 0.18), 9/12 atypical hyperplasias (75%, mean hTERT index 0.74), 8/9 intraepithelial carcinomas (89%, mean hTERT index 1.82), and 53/62 invasive laryngeal squamous cell carcinomas (85%, mean hTERT index 2.51). Statistical analysis revealed two groups of laryngeal epithelial changes with significant differences in the levels of hTERT mRNA expression (P <.0033): (1) normal and reactive hyperplastic laryngeal epithelium (simple and abnormal hyperplasia) and (2) atypical hyperplasia (precancerous lesion), intraepithelial and invasive laryngeal squamous cell carcinoma. The results of the present study suggest that telomerase reactivation is an early event in laryngeal carcinogenesis, detectable already at the stage of precancerous laryngeal epithelial changes. Nevertheless, other genetic abnormalities appear to be necessary for progression of these epithelial abnormalities toward invasive laryngeal squamous cell carcinoma.  相似文献   
4.
Although Smith-Lemli-Opitz Syndrome (SLOS), a genetic condition of impaired cholesterol biosynthesis, is associated with autism [Tierney et al., 2001; Am J Med Genet 98:191-200.], the incidence of SLOS and other sterol disorders among individuals with autism spectrum disorders (ASD) is unknown. This study investigated (1) the incidence of biochemically diagnosed SLOS in blood samples from a cohort of subjects with ASD from families in which more than one individual had ASD and (2) the type and incidence of other sterol disorders in the same group. Using gas chromatography/mass spectrometry, cholesterol, and its precursor sterols were quantified in 100 samples from subjects with ASD obtained from the Autism Genetic Resource Exchange (AGRE) specimen repository. Although no sample had sterol levels consistent with SLOS, 19 samples had total cholesterol levels lower than 100 mg/dl, which is below the 5th centile for children over age 2 years. These findings suggest that, in addition to SLOS, there may be other disorders of sterol metabolism or homeostasis associated with ASD.  相似文献   
5.
The high temperature (up to 220°C.) polymerization of 3,3-bis(chloromethyl)oxetane catalyzed by i-Bu3Al was investigated. The conversion-time curves are of the autocatalytic type and the molecular weight increases lineary with conversion up to the point at which for lower temperatures, e.g. 60–80°C., the whole polymer becomes insoluble. An alternative explanation of this phenomenon is proposed; the formation of insoluble product is related to the entanglement of macromolecules of very high molecular weight and or macrocycle formation in the degradative chain transfer to polymer. The phenomenon of insoluble products formation was never observed at higher temperatures (> 150°C.). The dependence of molecular weight on catalyst and impurity concentrations as well as on the polymerization temperature was investigated. It was shown that the high molecular weight product (\documentclass{article}\pagestyle{empty}\begin{document}$\overline {DP}$\end{document} = 1000–1500) can be produced at 180–220°C. even at rather high impurity level.  相似文献   
6.
In the polymerization of 3,3-bis(chloromethyl)oxetane catalyzed by Aliso-C4H9/water catalyst, according to the previously reported data (FURUKAWA, SAEGUSA et al.) insoluble polymers are formed. Although neither the exact mechanism of oxetanes polymerization in the presence of AIR3/H2O catalysts nor the nature of the insoluble polymers are known it is possible to use chain transfer agents to obtain perfectly soluble polymers. The addition of low molecular weight ethers (C2H5)2O, (n-C4H9)2O, (Allyl)2O, 1,4-dioxane, (β-ClC2H4)2O, CH3OPh, and (C6H5)2O in low concentrations leads to the formation of soluble polymers with a very large range of mol. wts. (up to 106). The chain transferabilities of ethers increase with their proton-attracting powers (basicity). In the presence of a chain transfer agent the kinetics of polymerization virtually changes. On the basis of the discussion of the general kinetic behaviors of the system and the dependence of D?P? on conversion it was deduced that in this type of polymerization long living species are formed.  相似文献   
7.
A 51-year-old man, heavy cigarette smoker, a homeless alcoholic, with disseminated lesions in lungs and with ulceration and infiltration of the tongue is presented. Treatment with antibiotics was ineffective. He was admitted to the otolaryngological department because of suspicion of the tongue cancer. The histological examination of the tongue biopsy revealed tuberculous granuloma. In the pulmonological department, on admission the patient was cachectic, with massive oedema and ulceration of the tongue, and enlargement of the cervical lymph nodes. He was fed through the gastric tube. He had severe pain of the tongue demanding treatment with opiates analgesics. Chest x-ray revealed disseminated lesions in lungs. Antituberculous therapy was administered because of suspicion of tuberculosis of the tongue and lungs. During the treatment clinical improvement was observed. Tubercule bacilli were grown in the sputum culture after 6 weeks of observation. After 8 weeks of antituberculous therapy regression of lung lesions and healing of the tongue were observed. The patient continued treatment for 6 months in the Lung Disease Outpatient Clinic.  相似文献   
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9.
IntroductionA fast and cheap method of skin assessment in systemic sclerosis (SSc) is an area of extensive research. Established in 1979, the Rodnan skin score is a palpation-based method used among clinicians. This method has some limitations, such as: examiner’s skills, subjective results, and no standardization. In the last few years researchers have been exploring ultrasound-based techniques as a possible tool for skin assessment among patients with SSc. The aim of the study is to develop a protocol of elastography-based skin imaging evaluation among patients with SSc.Material and methodsReview of the literature and own experience.ResultsProposition of elastography-based skin imaging protocol among patients with SSc.ConclusionsThe authors present a potential protocol of ultrasound-based examination of skin involvement among patients with SSc.  相似文献   
10.
Stereotactic angiography has long been the imaging database for the radiosurgical treatment of arteriovenous malformations (AVM). The following analysis reveals systematic shortcomings in the methodology, resulting in errors in determining target shape, errors in determining target size, and errors in the identification of the true AVM "nidus."  相似文献   
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