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- Wängberg, Bo, 1953, et al.
(författare)
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Somatostatin Receptors in the Diagnosis and Therapy of Neuroendocrine Tumor.
- 1997
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Ingår i: The oncologist. - 1549-490X. ; 2:1, s. 50-58
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Tidskriftsartikel (refereegranskat)abstract
- The expression of somatostatin receptors in neuroendocrine tumors has facilitated the diagnosis and surgical treatment of patients with these tumors. After injection of a radiolabeled long-acting somatostatin analog, (111)In-octreotide, scintigraphic tumor imaging can ben performed as well as intraoperative tumor localization. During localization studies very high (111)In concentration values were found in tumor tissues versus normal tissues, especially in carcinoid tumors and endocrine pancreatic tumors. Studies on such tumors in cell culture further indicated internalization of (111)In into tumor cells, which is a prerequisite for a radiobiological effect from short range Auger and conversion electrons. Attempts to systemic radionuclide therapy via somatostatin receptors in patients with neuroendocrine tumors have been initiated.
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| 2. |
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| 3. |
- Fjälling, M, et al.
(författare)
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Systemic radionuclide therapy using indium-111-DTPA-D-Phe1-octreotide in midgut carcinoid syndrome.
- 1996
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Ingår i: Journal of nuclear medicine : official publication, Society of Nuclear Medicine. - 0161-5505. ; 37:9, s. 1519-21
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Tidskriftsartikel (refereegranskat)abstract
- A 55-yr-old woman with a midgut carcinoid syndrome due to metastatic spread of an ileal tumor to the liver, paraortic and mediastinal lymph nodes and to the skeleton was given systemic radionuclide therapy with 111In-DTPA-D-Phe1-octreotide. Before therapy, dosimetric calculations were performed on whole-body scintigraphs and 111In retention was shown to be long-lasting. Excretion was mainly seen during the first 24 hr after injection; thereafter whole-body retention remained stationary at 30%. Indium-111 activity in tumor biopsies and blood was measured using a gamma counter. Very high tumor-to-blood ratios were obtained: 150 for the primary tumor and 400-650 for liver metastases, which further justified radiation therapy. Indium-111-DTPA-D-Phe1-octreotide treatment was given on three separate occasions (3.0, 3.5 and 3.1 GBq) 8 and 4 wk apart. After each therapy, the patient experienced facial flush and pain over the skeletal lesions followed by symptomatic relief, even though no objective tumor regression was found radiologically after 5 mo. After initiation of octreotide treatment, there was a 14% reduction of the main tumor marker, urinary 5-HIAA. After three subsequent radionuclide therapies, there was a further 31% reduction of 5-HIAA levels. No adverse reactions, other than a slight decrease in leukocyte counts, were seen. The mean absorbed radiation dose after the three treatments was estimated to be about 10-12 Gy in liver metastases and 3-6 Gy in other tumors, depending on the size and location of the metastases. Assuming internalization of 111In into tumor cells and a radiobiological effect from short range Auger and conversion electrons, there might be a therapeutic effect on the tumor.
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| 4. |
- Håkansson, Lars, et al.
(författare)
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Adaptiv reglering av verktygsvibrationer i svarvoperationen
- 1998
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Konferensbidrag (refereegranskat)abstract
- I svarvoperationen är relativ dynamisk rörelse mellan verktyg och arbetsstycke ett vanligt förekommande problem. Rörelsen påverkar bearbetningsresultatet, speciellt arbetsstyckets yta, men även verktygets livslängd påverkas. Arbetsmiljöproblem som buller förekommer också på grund av vibrationer i svarvoperationen. Problemet kan delvis lösas med lämplig konstruktion som ökar styvheten i maskinstrukturen, vilken dock begränsas av den dynamiska styvheten i strukturen hos verktygshållare samt arbetsstycke. Med aktiv reglering av verktygshållarens respons, dvs. aktiv reglering av verktygsvibrationer, kan en ytterligare ökning av den dynamiska styvheten i det skärtekniska systemet erhållas. Regleringen av verktygsvibrationer har utförts med en återkopplad regulator som är baserad på den så kallade "filtered-x LMS"-algoritmen samt aktuatorer baserade på magnetostriktiv teknik. Verktygshållarens respons, verktygsvibrationerna, detekteras med en givare (accelerometer) som är monterad på verktygshållaren. Genom att introducera motvibrationer i verktygshållaren med en sekundär vibrationskälla, aktuator, via regulatorn som matas med de uppmätta vibrationerna, modifieras verktygshållarens respons. Med aktiv reglering av verktygsvibrationer uppmättes en reduktion av vibrationerna med ca 30 dB vid 1.7 kHz. Vidare erhölls en signifikant förbättring av arbetsstyckets yta och en avsevärd reducering av bullernivån erhölls.
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