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排序方式: 共有6827条查询结果,搜索用时 31 毫秒
61.
Dayananda S Sharma Rakesh Jalali Chandrashekhar M Tambe Deepak D AnimeshDeshpande 《Radiotherapy and oncology》2004,70(1):49-54
BACKGROUND AND PURPOSE: The aim of this work was to measure the dose to foetus both in vivo and in vitro during three-dimensional conformal radiation therapy (3DCRT) in a pregnant patient with a pituitary adenoma. The study was then extended to assess the components contributing to the foetal dose such as collimator scatter, internal scatter, head leakage, wedge scatter and multileaf collimator (MLC) effect. PATIENTS AND METHODS: A 30-year-old pregnant woman with a non-functioning pituitary macroadenoma was planned for 3DCRT with 6MV X-ray using four equally weighted MLC-shaped non-coplanar wedged portals. In vivo dosimetry was carried out using thermoluminescent (TL) phosphor powder, which was placed at different positions on the patient, corresponding to different locations in the uterus and also at external os. In vitro measurements were also performed on a simulated phantom using the same set-up parameters and beam arrangement to verify the in vivo measured dose. Experiments were carried out to measure the respective contributions of different components towards peripheral dose. RESULTS: In vitro measured dose to foetus was found to be slightly more than that of in vivo measurement with a maximum of 0.044% of the prescribed dose of 45Gy, which corresponded to 0.0199+/-0.0008Gy. Thermoluminescence dosimeter (TLD) kept at the external os of the patient showed a dose of 0.031% of the prescribed dose. Among the various components of the peripheral dose (foetal dose) measured, head leakage was found to be the leading cause contributing 52%, followed by wedge scatter (31%), collimator scatter (14%) and internal scatter (13%). The use of MLC reduced not only the volume of normal brain irradiation as compared to open fields but also the peripheral dose by 10%. CONCLUSION: Radiotherapy of brain tumours during pregnancy poses a unique clinical situation and decisions to deliver radiotherapy should be taken after detailed in vitro and in vivo dosimetric measurements. Our findings suggest that the beam arrangement using 3-4-fields generally used for 3DCRT of brain tumour with MLC for optimal coverage can be employed for pregnant patients even in early trimester. A possible increase in foetal dose from wedges to a large extent can be compensated with the use of MLC. 相似文献
62.
Hemant Parmar Deepak Patkar Jeshil Shah Tufail Patankar 《Journal of Medical Imaging and Radiation Oncology》2003,47(4):438-442
Hemimegalencephaly is a rare cerebral malformation characterized by asymmetry of the hemispheres and cortical dysplasias. We report clinical and imaging findings in a child with hemimegalencephaly involving the right cerebral hemisphere with associated manifestations of tuberous sclerosis complex. Gross abnormal myelination pattern and gyral abnormalities were seen in the enlarged hemisphere. Subsequent scans showed atrophy of the frontoparietal region in the enlarged hemisphere and normal growth of the opposite hemisphere exceeding the size of the abnormal hemisphere in the frontoparietal region. A few white‐matter lesions that were seen in the normal hemisphere on neonatal scan were difficult to appreciate on subsequent MR studies. The white‐matter lesions were better seen in the neonatal period, whereas cortical tubers were better detected at a later age. 相似文献
63.
P. M. Parikh S. H. Advani J. S. Nadkarni S. Kulkarni G. Kapoor P. S. R. K. Sastry M. Anand T. K. Saikia R. Gopal 《Cancer investigation》1997,15(4):326-328
Hepatic veno-occlusive disease (VOD) is the second most common cause of death after autologous bone marrow transplantation (ABMT). A patient with multiple myeloma undergoing ABMT developed classic features of hepatic VOD. He responded to treatment with pentoxiphyllin. Serum tumor necrosis factor (TNF) levels showed remarkable correlation with the severity of VOD and response to therapy. 相似文献
64.
Patankar T Krishnan A Patkar D Kale H Prasad S Shah J Castillo M 《Skeletal radiology》2000,29(7):392-396
Objective. To review imaging studies of isolated involvement of the sacrum due to tuberculosis and determine the role of imaging in
the diagnosis and management of these patients.
Design and patients. A retrospective analysis of 15 cases of isolated sacral tuberculosis imaged with MR imaging was performed. The CT images
were also reviewed where available, and the various lesion characteristics were identified. We also reviewed the medical records
in an attempt to determine the impact of the imaging studies on the management of these patients.
Results. Fifteen patients (5 male, 10 female) presented with symptoms of 3–15 months’ duration. Chronic localized backache with muscle
spasm was the commonest presenting symptom; discharging sinuses with abscess formation was found in six patients, five of
whom were children. MR imaging of the sacrum revealed a hypointense marrow signal on T1-weighted images and hyperintense signal
on T2-weighted images in 14 of 15 patients, the S2 vertebra being always involved. CT revealed osteolytic changes in the sacrum
in all the five patients in whom CT was performed. All patients showed marked clinical improvement within 1 year of anti-tuberculous
chemotherapy.
Conclusion. Isolated tuberculosis of the sacrum is uncommon but should be suspected in patients presenting with chronic low backache
or children with discharging sinuses/abscesses and showing sacral destruction on CT or MR imaging. MR imaging can identify
cases and enables early institution of anti- tuberculous chemotherapy.
Received: 31 August 1999 Revision requested: 1 November 1999 Revision received: 27 March 2000 Accepted: 14 April 2000 相似文献
65.
G. K. Maheshwari H. A. Baboo Usha Gopal M. K. Wadhwa 《Indian journal of otolaryngology and head and neck surgery》2004,56(2):138-141
Sarcomas constitute fewer than 1% of the head and neck cancers. They represent less than 1% of laryngeal cancers. Primary
rhabdomyosarcoma of the larynx is an extremely rare malignancy. The available literature on this medical oddity is in the
form of isolated case reports only. The purpose of this article is to add another case of primary rhabdomyosarcoma of a rare
site, the larynx, of which only 36 cases have so far been reported in the world literature. The present patient, an eighteen-year-old
boy is only the third case being reported from India among all reported cases of rhabdomyosarcoma of the larynx in the world
literature. 相似文献
66.
I. E. Ezeagu A. G. Gopal Krishna S. Khatoon L. R. Gowda 《Ecology of food and nutrition》2004,43(4):295-305
Analysis showed the seeds of Adenanthera pavonina contained appreciable amounts of proteins (29.44g/100g), crude fat (17.99g/100g), and minerals, comparable to commonly consumed staples. Total sugar was low (8.2g/100g) while starch (41.95g/100g) constitutes the major carbohydrates. Low levels of antinutrients were reported and methionine and cystine were the most deficient amino acids. Linoleic and oleic acids make up 70.7 percent of the total fatty acids. Free fatty acid levels were relatively high but peroxide and saponification values of 29.6mEqkg-1 and 164.1mgKOHg-1respectively point to a resemblance to oils processed for food. It was concluded that A. pavonina seeds represent a potential source of oil and protein that could alleviate shortages. 相似文献
67.
Brain undergoes neurodegeneration when excess free radicals overwhelm antioxidative defense systems during senescence, head trauma and/or neurotoxic insults. A site-specific accumulation of ferrous citrate-iron complexes in the substantia nigra dopaminergic neurons could lead to exaggerated dopamine turnover, dopamine auto-oxidation, free radical generation, and oxidant stress. Eventually, this iron-catalyzed dopamine auto-oxidation results in the accumulation of neuromelanin, a progressive loss of nigral neurons, and the development of Parkinson's disease when brain dopamine depletion is greater than 80%. Emerging evidence indicates that free radicals such as hydroxyl radicals ((.-)OH) and nitric oxide ((.-)NO) may play opposite role in cell and animal models of parkinsonism. (.-)OH is a cytotoxic oxidant whereas oNO is an atypical neuroprotective antioxidant. (.-)NO and S-nitrosoglutathione (GSNO) protect nigral neurons against oxidative stress caused by 1-methyl-4-phenylpyridinium (MPP(+)), dopamine, ferrous citrate, hemoglobin, sodium nitroprusside and peroxynitrite. MPP(+), the toxic metabolite of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), increases the nigral uptake of iron complexes and dopamine overflow leading to the generation of (.-)OH, protein oxidation, lipid peroxidation, and associated retrograde degeneration. In addition to GSNO, MPP(+)-induced oxidative neurotoxicity can be prevented by antioxidants including selegiline, 7-nitroindazole, 17beta-estradiol, melatonin, alpha-phenyl-tert-butylnitrone and U78517F. Similar to selegiline, 7-nitroindazole is a MAO-B inhibitor, which blocks the bio-activation of MPTP and oxidative stress. Freshly prepared but not light exposed, (.-)NO-exhausted GSNO is about 100 times more potent than the classic antioxidant glutathione. Via S-nitrosylation, GSNO also inhibits proteolysis and cytotoxicity caused by caspases and HIV-1 protease. Furthermore, in addition to protection against serum deprivation stress, the induction of neuronal NOS1 in human cells increases tolerance to MPP(+)-induced neuro-toxicity since newly synthesized (.-)NO prevents apoptosis possibly through up-regulation of bcl-2 and down regulation of p66(shc). In conclusion, reactive oxygen species are unavoidable by-products of iron-catalyzed dopamine auto-oxidation, which can initiate lipid peroxidation, protein oxidation, DNA damage, and nigral loss, all of which can be prevented by endogenous and exogenous (.-)NO. Natural and man-made antioxidants can be employed as part of preventative or neuroprotective treatments in Parkinson's disease and perhaps dementia complexes as well. For achieving neuroprotection and neuro-rescue in early clinical parkinsonian stages, a cocktail therapy of multiple neuroprotective agents may be more effective than the current treatment with extremely high doses of a single antioxidative agent. 相似文献
68.
Gupta Sumita Mukherjee Aparna Lodha Rakesh Kabra Madhulika Deepak Kishore K. Khadgawat Rajesh Talwar Anjana Kabra Sushil Kumar 《Indian journal of pediatrics》2019,86(11):987-994
Indian Journal of Pediatrics - To evaluate effect of one year exercise intervention program on bone mineral accrual in children and adolescent with cystic fibrosis (CF). Fifty-two CF children (mean... 相似文献
69.
Tisungane Mvalo Hillary M. Topazian Portia Kamthunzi Jane S. Chen Isobel Kambalame Pilirani Mafunga Noel Mumba Msandeni Chiume Khadija Paseli Gerald Tegha Wiza Kumwenda J. Brett Heimlich Graham Ellis Nigel Key Satish Gopal Irving Hoffman Kenneth I. Ataga Kate D. Westmoreland 《Pediatric blood & cancer》2019,66(11)
70.