Search PubMed⌕ Search

Biomedical subjects

A Morgenstern

Publications and source records attributed to A Morgenstern.

14 recordsLinked to original sources
PubMed2006

Antibody-guided alpha radiation effectively damages fungal biofilms.

The use of indwelling medical devices--pacemakers, prosthetic joints, catheters--is rapidly growing and is often complicated by infections with biofilm-forming microbes that are resistant to antimicrobial agents and host defense mechanisms. We investigated for the first time the use of microbe-specific monoclonal antibodies (MAbs) as delivery vehicles for targeting biofilms with cytocidal radiation. MAb 18B7 (immunoglobulin G1 [IgG1]), which binds to capsular polysaccharides of the human pathogenic fungus Cryptococcus neoformans, penetrated cryptococcal biofilms, as shown by confocal microscopy. When the alpha radiation-emitter 213-Bismuth ((213)Bi) was attached to MAb 18B7 and the radiolabeled MAb was added to C. neoformans biofilms, there was a 50% reduction in biofilm metabolic activity. In contrast, when the IgM MAb 13F1 labeled with (213)Bi was used there was no penetration of the fungal biofilm and no damage. Unlabeled 18B7, (213)Bi-labeled nonspecific MAbs, and gamma and beta types of radiation did not have an effect on biofilms. The lack of efficacy of gamma and beta radiation probably reflects the radioprotective properties of polysaccharide biofilm matrix. Our results indicate that C. neoformans biofilms are susceptible to treatment with antibody-targeted alpha radiation, suggesting a novel option for the prevention or treatment of microbial biofilms on indwelling medical devices.

Alpha Particles↗
PubMed2005

Production of Ac-225 from Th-229 for targeted alpha therapy.

This work describes a method for the separation and purification of Ac-225 from a Th-229 source. The procedure is based on the combination of ion exchange and extraction chromatographic methods in nitric acid media and allows the preparation of carrier-free, clinical grade Ac-225 with an overall yield exceeding 95%. Quality control of the product is performed using radiometric (alpha, gamma spectrometry) and mass spectrometric methods. The Ac-225 product can be loaded on a radionuclide generator for the preparation of Bi-213 for preclinical and clinical studies of targeted alpha therapy of cancer and infectious diseases.

Actinium↗
PubMed2005

Cyclotron production of Ac-225 for targeted alpha therapy.

The feasibility of producing Ac-225 by proton irradiation of Ra-226 in a cyclotron through the reaction Ra-226(p,2n)Ac-225 has been experimentally demonstrated for the first time. Proton energies were varied from 8.8 to 24.8 MeV and cross-sections were determined by radiochemical analysis of reaction yields. Maximum yields were reached at incident proton energies of 16.8 MeV. Radiochemical separation of Ac-225 from the irradiated target yielded a product suitable for targeted alpha therapy of cancer.

Actinium↗
PubMed2002

Age determination of highly enriched uranium: separation and analysis of 231Pa.

An analytical procedure has been developed for the age determination of highly enriched uranium samples exploiting the mother/daughter pair 235U/231Pa. Protactinium is separated from bulk uranium through highly selective sorption to silica gel and is subsequently quantified using alpha-spectrometry. The method has been validated using uranium standard reference materials of known ages. It affords decontamination factors exceeding 2.5 x 10(7), overall recoveries in the range of 80-85%, and a combined uncertainty below 5%.

Half-Life↗
PubMed2002

Determination of the age of highly enriched uranium.

This paper describes the analytical methods (thermal ionization mass spectrometry, inductively coupled plasma mass spectrometry, and alpha spectrometry) that have been developed for determination of the age of uranium and discusses their advantages and limitations. With regard to potential application of the methods (e.g. Fissile Material Cut-off Treaty), the discussion focuses on highly enriched uranium, because this seems to be of highest strategic relevance. The different analytical methods were tested and validated by use of uranium reference materials of different (235)U isotope abundance and of known ages. The results show that thermal ionization mass spectrometry and alpha spectrometry are both very accurate and precise techniques for this application. Inductively coupled plasma mass spectrometry, on the other hand, although less precise, because of the different approach to the analytical problem, is still sufficiently accurate to be used as a rapid screening method.

Journal Article↗
PubMed1994

Adequacy of dialysis and nutritional status in hemodialysis patients.

Twenty-three nondiabetic end-stage renal failure patients on hemodialysis were studied for adequacy of dialysis and nutritional status. Midweek predialysis blood urea nitrogen was 27.1 +/- 6.4 mmol/l of urea, KT/V, according to urea kinetic modelling, was 1.21 +/- 0.22 and mean normalized protein catabolic rate (nPCR) was 1.15 +/- 0.23 g/kg/day. Only 1 patient had a KT/V less than 1 and 4 patients had an nPCR less than 1 g/kg/day. No correlation was found between the different nutritional parameters. All patients had normal serum albumin. However, some of the patients could be classified as severely malnourished when parameters such as body weight (2 patients), triceps skinfold (5) and total lymphocyte count (3) were taken into account. No correlation was found between adequacy of dialysis and the different nutritional parameters. Furthermore, when patients were divided into low and normal KT/V, no differences were found in their nPCR. We conclude that a global assessment of the nutritional status is required in hemodialysis patients, and at least in patients with an acceptable KT/V, nPCR is not dependent on the adequacy of dialysis.

Adult↗
PubMed1980

[Urbanization and development of the urban population in the German Democratic Republic].

The authors present evidence that "urbanisation in the GDR [German Democratic Republic] has considerably increased within the last 30 years though statistically the urban population has only slightly grown. Urbanisation is seen as a socio-economic process, as a stage-by-stage transition from the rural to the urban way of life. The socialist changes led to a spread and consolidation of the urban way of life. With the population trend stagnant, there are long-term regional concentration processes apparent, marked by the further development and a more equal distribution of large and medium towns." (SUMMARY IN ENG, RUS)

Demography↗
PubMed1980

Reliving the last goodbye: the psychotherapy of an almost silent patient.

Periods of silence in psychotherapy have many meanings and often possess extreme emotional power. In this paper I will describe prolonged silences shared with a young woman, which had an unconscious significance not yet explored in the extensive psychoanalytic literature concerning silence. Within the context of a 30-session focal psychotherapy she was comfortably silent most of the time during our first 25 meetings. Her serene soundlessness was eventually understood as a reliving of the quiet Olympian detachment she had observed in her father as he lay dying a few years earlier.

Adolescent↗
PubMed1975

Experiences within a borderline syndrome.

This paper provides an experiential view of a borderline syndrome and its psychotherapy. In a letter to her therapist a gifted patient speaks of the symptoms and treatment of her illness. This provides the basis for studying the precipitous transference relationships in borderline patients and the urgent need in these patients for clarity and dependability from their therapists. Common fears of being "set adrift" by psychotherapy are contrasted to the characteristic tenacity of the patient-therapist bond. A review of the patient's life allows the reader to evaluate the clinical applicability of her insights. The letter's multiple communicative functions illustrate some of the qualities of the object relations sought by borderline personalities, and stress is placed upon the sublimatory aspect of such letters and the prognostic importance of the capacities for sublimation.

Acting Out↗