Biomedical subjects

O J Visser

Publications and source records attributed to O J Visser.

5 recordsLinked to original sources

PubMed2005

[Radio-immunotherapy for B-cell non-Hodgkin lymphoma].

Radio-immunotherapy is a new treatment modality for patients with B-cell non-Hodgkin lymphoma. In radio-immunotherapy, a therapeutic radionuclide is coupled to a monoclonal antibody directed against a tumour-specific or tumour-associated antigen. Biodistribution studies and dosimetry are used in the planning of radio-immunotherapy. Clinical studies, notably in patients with indolent non-Hodgkin lymphoma, have demonstrated the clinical feasibility and efficacy of this treatment. The use of a high dose ofradio-immunotherapy in combination with (high-dose) chemotherapy and peripheral stem-cell transplantation constitutes a supplemental treatment for patients who respond insufficiently or not at all to standard therapy. The exact place of radio-immunotherapy in the treatment of patients with non-Hodgkin lymphomas is not yet clear.

Chemotherapy, Adjuvant↗

PubMed2005

[Acute dyspnoea following transfusion of plasma-containing blood products].

A 35-year-old male patient who was given chemotherapy because of chronic myeloid leukaemia became dyspnoeic after transfusion of thrombocytes; initially, no explanation could be found for this dyspnoea. He went home before all diagnostic procedures were evaluated. Chest X-ray revealed bilateral pulmonary oedema, which could be due to transfusion-related acute lung injury (TRALI), especially since there were no indications for a cardiac aetiology. The patient was sent to the nearest hospital where he was treated with diuretics and observed for 24 hours. There were no complications. The pathogenesis of TRALI has been attributed to an interaction between anti-granulocyte antibodies and granulocytes. In addition, bioactive compounds produced during the storage of blood products have been implicated. It is important to recognize TRALI as the cause of dyspnoea when cardiac or pulmonary causes are excluded. The overall prognosis is good when treatment is started in time. The management of TRALI is supportive, with mechanical ventilation when necessary. After excluding donors with proven anti-granulocyte antibodies from further donation, there is no increased risk for recurrent episodes after future transfusion of plasma-containing blood products.

Acute Disease↗

PubMed2004

[Sternal pain: not always harmless].

In two patients, men aged 39 and 66 years, a sternal mass in combination with pain developed. One patient was diagnosed with a non-Hodgkin lymphoma located in the sternum and the other one with a primary chondrosarcoma of the sternum. They both recovered after treatment. The differential diagnosis of disorders of the chest wall is troublesome and includes haematologic, rheumatologic and infectious processes. Tietze's syndrome is a rare cause of pain and non-suppurative swelling of the costosternal joints. However, tumours of the anterior chest wall can also cause these symptoms and these must therefore be excluded if the complaints persist or the swelling progresses. The most common malignant tumours of the chest wall are non-Hodgkin lymphoma, primary chondrosarcoma and metastases. Diagnostics should consist of blood tests and X-rays. CT and MRI scans are more helpful in establishing the diagnosis. A definitive diagnosis can only be determined by biopsy.

Adult↗

PubMed1992

Inactivation and repair of double-stranded DNA damaged by the aziridinyl nitroimidazole RSU 1069.

Incubation of RSU 1069 in the presence of biologically active double-stranded phi X174 DNA resulted in, depending on pH, ionic strength and concentration of drug, inactivation of the DNA. A variety of lesions are induced including a high number of single-strand breaks and alkali-labile lesions, which are at most partly lethal. The main inactivating damage consists probably of base damage, induced by alkylation. A considerable part of the damage induced by RSU 1069 can be repaired by the various repair enzymes of the bacterial host of the phi X174 DNA. Finally the damage (pattern) depends considerably on the ionic composition of the reaction solution, which can be explained by an equilibrium model presented in this paper.

Alkalies↗

PubMed1991

Interaction of RSU 1069 and 1137 with DNA in vitro. Biological implications and mechanistic aspects.

We have examined the capacity of the nitroimidazole aziridine antitumour drug RSU 1069 to react with DNA in vitro in order to get a better understanding of its mechanism of action. Moreover, we have utilized biologically active phi X174 DNA to investigate the biological relevance of the chemical DNA modification induced by the drug. Incubation of RSU 1069 in the presence of single-stranded phi X174 DNA resulted in extensive inactivation of the DNA, which is dependent on the concentration of drug and temperature. Only about 2% of the inactivating damage can be attributed to strand breakage. The main damage most probably consists of base damage, of which a part is non-lethal and alkali-labile which in turn can be converted into lethal lesion and subsequently into a break applying a post-incubation alkali treatment. Furthermore, from the dependence of the inactivation and also the formation of breaks on pH and ionic strength, it is concluded that the reaction most probably takes place between a protonated RSU 1069 and a negative DNA coil and that the damage pattern reflects the difference in reactivity of RSU 1069 with the phosphate groups and the bases in DNA. Comparison between RSU 1069 and its ring-open hydrolysis product RSU 1137 revealed that (lethal) damage induced in the DNA must be ascribed to the alkylating properties of the aziridine moiety.

Alkalies↗