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Biomedical subjects

H Petersen

Publications and source records attributed to H Petersen.

212 records · Page 12Linked to original sources
PubMedDate not supplied

N-acetylcysteine augments adenovirus-mediated gene expression in human endothelial cells by enhancing transgene transcription and virus entry.

BACKGROUND: It has previously been shown that oxidants reduce the efficiency of adenoviral transduction in human umbilical vein endothelial cells (HUVECs). In this study, the effect of the antioxidant N-acetylcysteine (NAC) in adenovirus-mediated gene transfer has been investigated. METHODS: HUVECs were pretreated or not with NAC, and infected with E1E3-deleted adenovirus (Ad) containing the LacZ gene expressed from the RSV-LTR promoter/enhancer in the presence and absence of NAC. Transgene expression was assessed at the protein level (histochemical staining, measurement of beta-Gal activity, and western blot), mRNA level (real-time RT-PCR) and gene level (nuclear run on) 24 h and 48 h after infection. Adenoviral DNA was quantitated by real-time PCR, and cell surface expression of Coxsackie/adenovirus receptors (CAR) was determined by FACS analysis. RESULTS: Pretreatment of cells with NAC prior to Ad infection enhanced beta-Gal activity by two-fold due to an increase in viral DNA, which was related to increased CAR expression. When NAC was present only during the post-infection period, a five-fold increase in beta-Gal activity and LacZ gene transcriptional activity was observed. When NAC was present during both the pretreatment and the post-infection period, beta-Gal activity was further enhanced, by 15-fold. Augmentation of beta-Gal activity was paralleled by an increase in beta-Gal protein and mRNA levels. NAC did not affect the half-life of LacZ mRNA. CONCLUSION: Pretreatment with NAC prior to Ad infection enhances virus entry, while treatment with NAC post-infection increases transgene transcription. This strategy permits the use of lower adenoviral loads and thus might be helpful for gene therapy of vascular diseases.

Acetylcysteine↗
PubMedDate not supplied

Cholesteatoma surgery with the canal-wall-down technique.

This is a retrospective study of a limited group of 30 patients, children and adults, diagnosed as having cholesteatomas. Analysis includes audiological data and surgical results. Two techniques were used in surgery. In half of the cases, an obliteration technique was used, and in the remainder an open radical cavity was created. The method used was determined by the surgeon and in some measure by the extent of the disease. Our conclusions are that the obliteration technique offers better hearing results than the open-cavity technique. The number of residuals over a 4- to 5-year period was acceptable and cavity problems were avoided.

Adolescent↗
PubMedDate not supplied

Hematopoietic growth factors in patients receiving intensive chemotherapy for malignant disorders: studies of granulocyte-colony stimulating factor (G-CSF), granulocyte-macrophage colony stimulating factor (GM-CSF), interleukin-3 (IL-3) and Flt-3 ligand (Flt3L).

The levels of hematopoietic growth factors in patients receiving intensive chemotherapy for malignant disorders were investigated using a variety of approaches. Firstly, serum levels of granulocyte-macrophage colony-stimulating factor (GM-CSF), G-CSF and Flt3-ligand (Flt3L) were examined in acute leukemia patients with treatment-induced cytopenia and complicating bacterial infections. Increased serum levels of both G-CSF and Flt3-ligand (Flt3L) were detected when these patients developed therapy-induced leukopenia, whereas GM-CSF levels were low or undetectable. Development of complicating bacterial infections then increased the serum levels of both G- and GM-CSF, and the Flt3L levels remained high during the infections. Secondly, release of growth factors was characterized for clonogenic T cells that remained in the circulation of acute leukemia patients with chemotherapy-induced cytopenia. CD4(+) and CD8(+) T cells from these patients released high levels of GM-CSF, relatively low levels of IL-3 secretion having been detected, and only a minority of the clones released detectable amounts of Flt3L. Thus, circulating T cells may contribute to the high systemic growth factor levels in cytopenic patients. Thirdly, plasma levels of GM-CSF and interleukin-3 (IL-3) were examined in patients with malignant disorders who received chemotherapy plus G-CSF for stem cell mobilization. Increased levels of GM-CSF and Flt3L were detected both in the patients' plasma and in the stem cell grafts. Despite the increased growth factor levels in neutropenic patients with complicating infections, the occurrence of febrile neutropenia did not have a major impact on normal hematopoietic reconstitution (i.e. duration of treatment-induced neutropenia) after intensive chemotherapy for acute myelogenous leukemia.

Adolescent↗
PubMedDate not supplied

Effects of synthetic secretin on gastric secretion in man.

Five healthy subjects received on one occasion 2 mug/kg-hour of pentagastrin alone and on another occasion in combination with synthetic secretin (Schwarz/Mann) in the dose of 2 U/kg-hour. The gastric and duodenal contents were collected continuously through a gastroduodenal Lagerlöf tube. Polyethylene glycol and 57Co labelled vitamin B12 were used as non absorbable markers in the duodenum and in the stomach, respectively. In each subject synthetic secretin inhibited acid (mean inhibition 17 percent) and stimulated pepsin secretin (mean stimulation 49 percent). The findings indicate that these actions are properties of secretin itself.

Adult↗