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41.
CP Gibbs TD Peabody AJ Mundt AG Montag MA Simon 《Canadian Metallurgical Quarterly》1997,79(6):888-897
We reviewed the cases of sixty-two patients who had had a subcutaneous sarcoma to determine the effect of tumor and treatment-related variables on the rates of survival and local recurrence. Fifty-nine (95 per cent) of the patients had had an operation at another hospital before being referred to us. Twenty-nine (47 per cent) of the sixty-two tumors were high-grade, forty-two (68 per cent) were small (five centimeters or less), and thirty (48 per cent) were malignant fibrous histiocytomas. We followed a treatment strategy that consisted of repeat excision with the goal of obtaining wide margins. Excluding thirteen patients who had had a palpable local recurrence at the time of presentation, twenty (49 per cent) of forty-one patients who had had a marginal excision at another hospital had microscopic residual tumor on repeat excision. At a median of fifty-six months after the repeat excision, fifty (81 per cent) of the sixty-two patients had been continuously disease-free, one had no evidence of disease, eight had died of the disease, and three had died of other causes. The five-year rate of disease-free survival was 85 per cent (fifty-three of sixty-two patients). There were three local recurrences, all in patients who had had a marginal resection. No recurrences were noted in patients who had had a wide local excision of the tumor or of the previous operative field. Multivariate analysis revealed that a large tumor (greater than five centimeters), a marginal excision, and adjuvant radiation therapy were associated with a worse prognosis. Excellent rates of survival for patients who have a subcutaneous sarcoma, including those who have a large or high-grade tumor and those who have residual tumor following a previous operation, can be obtained with carefully planned operative treatment alone. We recommend operative excision or repeat excision with wide margins because of the high prevalence of residual tumor. Size is the most important tumor-related factor, and the operative margin is the most important treatment-related factor. The additional value of adjuvant radiation therapy remains unproved. 相似文献
42.
The role of a depressor factor, atrial natriuretic peptide, in the development of arterial hypertension in adolescents with pubertal hypothalamic syndrome was studied in 52 patients and 13 healthy males aged 13-24 years. The duration of disease was 2-11 years. Radioimmunological methods were used to measure plasma atrial natriuretic peptide, plasma renin activity, and serum aldosterone. Patients with borderline arterial hypertension were found to have a significant reduction in their atrial natriuretic peptide levels, and this correlated directly with the renin-aldosterone system, demonstrating insufficiency of the depressor system in patients with pubertal hypothalamic syndrome and the involvement of atrial natriuretic peptide in the development of arterial hypertension, along with disturbances in the functional relationship between atrial natriuretic peptide and the renin-aldosterone system. 相似文献
43.
FM Loehrer CP Angst FP Brunner WE Haefeli B Fowler 《Canadian Metallurgical Quarterly》1998,13(3):656-661
BACKGROUND: Elevated homocysteine concentrations have been associated with premature arteriosclerosis and with impairment of key methylation reactions through accumulation of the homocysteine metabolite S-adenosylhomocysteine. In end-stage renal failure high homocysteine concentrations are commonly found but thus far the concentrations of related adenosylated metabolites in plasma have not been assessed. METHODS: In this prospective study we determined plasma homocysteine and related metabolites in 25 patients on regular haemodialysis, and in 40 healthy volunteers. Blood samples from patients were drawn immediately before and in 10 patients additionally after the dialysis session. RESULTS: Folic acid and vitamin B12 in plasma were similar in patients (mean +/- SEM 25+/-2 nmol/l and 400+/-41 pmol/l respectively) and controls (24+/-3 and 324+/-23 respectively). In patients plasma homocysteine, S-adenosylmethionine and S-adenosylhomocysteine were markedly elevated (36.6+/-3.6 micromol/l, 381+/-32nmol/l and 1074+/-55 nmol/l respectively) compared to the control values (6.8+/-0.4 micromol/l, 60+/-3 nmol/l and 24.4+/-1.1 nmol/l respectively) whereas the molar ratio of plasma S-adenosylmethionine and S-adenosylhomocysteine was significantly decreased (0.36+/-0.02 and 2.7+/-0.2 in patients and controls respectively). Haemodialysis failed to normalize the abnormal levels of these metabolites. CONCLUSION: Since the ratio of S-adenosylmethionine : S-adenosylhomocysteine is closely linked to the activity of numerous enzymatic methylation reactions, these results suggest that methylation may be impaired in these patients. 相似文献
44.
School-based condom distribution programs have generated considerable controversy across the country. In the present study 249 sexually active African American adolescents who did (n = 119) and did not (n = 130) use a condom during their initial sexual experience were compared to assess whether condom use at the onset of sexual activity was associated with later differences in sexual behavior. The results indicated that youths who used a condom from the onset of sexual activity were more likely to have used a condom in the most recent intercourse occasion, less likely to be diagnosed with a sexually transmitted disease (STD) or to combine substance use with sexual activity, endorsed more positive attitudes toward condoms, and were older when they initiated sexual activity. The findings have implications for condom availability programs and indicate that initial condom use was not associated with earlier onset of sexual activity and was associated with higher rates of precautionary behavior among sexually active minority adolescents. 相似文献
45.
The pre- and postnatal findings of a fetus with a de novo del(13)(pter-->q21:) and an occipital encephalocoele are described. Maternal serum alpha-fetoprotein (AFP) screening at 19 weeks' gestation demonstrated a high level of 2.5 multiples of the median (MOM) and ultrasonography at 27 weeks' gestation showed severe intrauterine growth retardation, cardiomegaly, an occipital encephalocoele, and a calvarial defect. Genetic amniocentesis revealed a karyotype of 46,XX,del(13)(pter-->q21:). The proband postnatally displayed additional abnormalities such as microphthalmia, hypertelorism, large low-set ears, and micrognathia. We discuss the association of central nervous system (CNS) malformations with 13q deletions and emphasize that pregnancies with neural tube defects warrant cytogenetic analysis, especially when additional fetal abnormalities and neonatal dysmorphism are observed. 相似文献
46.
47.
Román Gómez Gonz ález Cosío 《International Planning Studies》1998,3(3):367-389
The concept of capacity building for environmental protection and management refers to the process by which the abilities of societies to identify and solve environmental problems are developed. This work assumes a social constructivist perspective to the process of capacity building for environmental governance and thus depicts it as critically dependent on broader processes of political and socioeconomic modernization. In an attempt to depict such a process, a heuristic device is put forward as a model of capacity analysis. A theoretical discourse and new institutionalist perspectives are used to test such a model on a theoretical plane. Some preliminary conclusions are drawn from this theoretical exercise. 相似文献
48.
A model stomach, containing a food matrix and a synthetic gastric fluid, was used to study the bactericidal effect of ingested wine on Listeria innocua. Volumes of wine equivalent to the ingestion of one glass and half a bottle, led, over a period of less than 2 h, to a reduction of 3 and 4 logarithmic cycles of the initial population respectively. The influence of ethanol and organic acids, wine constituents with known antimicrobial properties, was investigated. Ethanol exhibited a higher bactericidal effect than the mixture of the main wine organic acids. When testing the organic acids separately, malic and lactic acids were found to have the strongest effect. The combination of ethanol with the organic acids acted synergistically but to a lesser extent than wine itself. The results suggest that the ingestion of wine during a meal may diminish the quantity of Listeria persisting further in the alimentary tract. 相似文献
49.
Paulo S. André António L. Teixeira Armando N. Pinto Lara P. Pellegrino Berta B. Neto José F. Rocha Joäo L. Pinto Paulo N. Monteiro 《ETRI Journal》2006,28(2):257-259
In this letter, we will evaluate the performance degradation of a 40 km high‐speed (40 Gb/s) optical system, induced by optical fiber variations of the chromatic dispersion induced by temperature changes. The chromatic dispersion temperature sensitivity will be estimated based on the signal quality parameters. 相似文献
50.
Fbio Gomes Costa Elias Andrade Braga Soraia Teixeira Brando Alexandre de Freitas Espeleta Zênis Novais da Rocha Lílian Maria Tosta Simplício Emerson Andrade Sales 《Applied Catalysis A: General》2005,290(1-2):221-226
Infrared and UV–vis studies of metallocene immobilization on silica are reported here. The results have indicated changes in the Zr coordination sphere of metallocene depending on the immobilization route used. The reaction of [(Cp)2ZrCl2] with silica formed [(Cp)2ZrCl]+[SiO]− species. The same metallocene, reacting with TMA modified silica, formed monomethylated and dimethylated species by the substitution of chloro for methyl ligands, stabilized on the surface by interaction with “MAO-like” species (methylaluminoxane, MAO). These monomethylated and dimethylated cationic zirconium species are the active centers for the polymerization reaction. Different order of TMA addition in the silica modification step generated surface species of a similar nature, differing in their relative quantities. The highest amount of these active species was obtained when the support was added to the TMA solution rather than adding the TMA solution to the silica support. This was the most significant parameter affecting catalytic activity in ethylene polymerization. 相似文献