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491.
Morphological characteristics of young and old murine hematopoietic stem cell niches, as modeled in vitro
Mojca Justin, Ema Rogac Randl, Veno Kononenko, Matej Hočevar, Damjana Drobne, Primož Rožman, 2023, original scientific article

Abstract: The hematopoietic stem cell (HSC) niche undergoes detrimental changes with age. The molecular differences between young and old niches are well studied and understood; however, young and old niches have not yet been extensively characterized in terms of morphology. In the present work, a 2D stromal model of young and old HSC niches isolated from bone marrow was investigated using light and scanning electron microscopy (SEM) to characterize cell density after one, two, or three weeks of culturing, cell shape, and cell surface morphological features. Our work is aimed at identifying morphological differences between young and old niche cells that could be used to discriminate between their respective murine HSC niches. The results show several age- specific morphological characteristics. The old niches differ from the young ones in terms of lower cell proliferating capacity, increased cell size with a flattened appearance, increased number of adipocytes, and the presence of tunneling nanotubes. In addition, proliferating cell clusters are present in the young niches but not in the old niches. Together, these characteristics could be used as a relatively simple and reliable tool to discriminate between young and old murine HSC niches and as a complementary approach to imaging with specific cellular markers.
Keywords: bone marrow, hematoopetic stem cell niche, aging, adipocytes, scanning electron microscopy
Published in DiRROS: 26.01.2024; Views: 172; Downloads: 75
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492.
Vehicle–bridge interaction modelling using precise 3D road surface analysis
Maja Kreslin, Peter Češarek, Aleš Žnidarič, Darko Kokot, Jan Kalin, Rok Vezočnik, 2024, original scientific article

Abstract: Uneven road surfaces are the primary source of excitation in the dynamic interaction between a bridge and a vehicle and can lead to errors in bridge weigh-in-motion (B-WIM) systems. In order to correctly reproduce this interaction in a numerical model of a bridge, it is essential to know the magnitude and location of the various roadway irregularities. This paper presents a methodology for measuring the 3D road surface using static terrestrial laser scanning and a numerical model for simulating vehicle passage over a bridge with a measured road surface. This model allows the evaluation of strain responses in the time domain at any bridge location considering different parameters such as vehicle type, lateral position and speed, road surface unevenness, bridge type, etc. Since the time domain strains are crucial for B-WIM algorithms, the proposed approach facilitates the analysis of the different factors affecting the B-WIM results. The first validation of the proposed methodology was carried out on a real bridge, where extensive measurements were performed using different sensors, including measurements of the road surface, the response of the bridge when crossed by a test vehicle and the dynamic properties of the bridge and vehicle. The comparison between the simulated and measured bridge response marks a promising step towards investigating the influence of unevenness on the results of B-WIM.
Keywords: interakcija vozilo in most, terestično lasersko skeniranje, neravnost vozišča, numerično modeliranje
Published in DiRROS: 26.01.2024; Views: 196; Downloads: 76
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Legislation on the protection of experimental animals
Dragica Ornik, Milan Pogačnik, 2001, review article

Abstract: The aim of this paper is to establish the current situation in the field of legislation on the protection of experimental animals in Slovenia. The protection of experimental animals has been regulated by the provisions of theProtection of Animals Act.1 On the basis of this act, the Instructions on Conditions for the Issuing of Authorisations for Experiments on Animals for Scientific and Research Purposes2 and the Rules on the Ethics Commission for Experiments on Animals 3 have been used. The basic protection of experimental animals is provided for by a system of permits for experiments on animals. Permits for experiments on animals are granted by the administrative authorities responsible for veterinary medicine in cases where experiments areurgently required for medical, veterinary medical, or scientific and research purposes and the results are expected to produce important new knowledge, or when the suffering of animals is ethically acceptable in comparison with what the experiment is expected to achieve; where, in cases ofbasic research, experimental aims cannot be achieved by any other method or procedure, the experiment is performed on the minimum possible number of animals of the lowest neurophysiological sensitivity and a method is used thatcauses the minimum level of suffering, pain or lasting harm. Staff involved in the execution of experiments or in the care and nursing of animals, the premises for the accommodation or rearing and provision of animals, and the installations and devices used must all comply with the set conditions. (Abstract truncated at 2000 characters)
Published in DiRROS: 26.01.2024; Views: 132; Downloads: 34
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498.
Persistent chromosomal aberrations in somatic cells in testicular cancer patients after different therapies
Cvetka Bilban-Jakopin, Marjan Bilban, 2001, original scientific article

Abstract: Background. The damage due to radiation or chemotherapeutic agents has been estimated successfully for the last 35 years from the numbers of the chromosome changes. This finding may serve as biological dosimeter. The aim ofthe study was to find persistent chromosomal aberrations in somatic cells intesticular cancer patients after different therapies. Patients and methods. This prospective study includes 60 patients with testicular tumours. With respect to the histological results and various therapies that they were giventhey were divided into four groups. Prior to treatment, we did not detectany deviations either in the genome picture of our patients or in that of the subjects of the control group without malignant disease. The changes inthe genome of individual cells after therapy were detected by the following tests: structural chromosomal aberrations (SCA) test, sister chromatid exchange (SCE) test and micronucleus (MN) test performed on binuclear lymphocytes. (Abstract truncated at 2000 characters)
Published in DiRROS: 26.01.2024; Views: 128; Downloads: 28
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499.
Evolving strategies in the treatment of childhood rhabdomyosarcoma : Slovenian experience
Živa Pohar-Marinšek, Jožica Anžič, Berta Jereb, 2001, original scientific article

Abstract: Background. Neoadjuvant chemotherapy (Cht) has changed the treatment of rhabdomyosarcoma (RMS) in children. The purpose of our study was to review thechildren treated for RMS between 1974 and 1996. Patients and methods. Fifty-one children, 1-15 years old, were included. Primary sites of tumour were: head and neck 15, orbit 6, genitourinary 12, extremity 9, torso 5 and paratesticular 4. Twelve patients were in stage 1, 10 in stage II, 26 in stage111 and 3 in stage IV. Of 43 histologically confirmed RMS 25 were embryonal, 13 alveolar, 1 botryoid, 1 spindle cell and 3 sarcoma NOS. In 8 patients, only fine needle aspiration biopsy (FNAB) was available. All patients had Cht, 29 neoadjuvant, 20 had surgery first, 40 had irradiation (RT), 2 stage IV patients had bone marrow transplant (ABMT). Multidrug Cht varied: VCR, AMD, and cyclophosphamide (VAC) were used in the 1970s, with Adriablastine (T2), methotrexat (MTX) and/or other drugs (T6, T11) in the 1980s; and in the 1990s, cyclophosphamide was replaced by ifosfamide (VAIA). The treatment was started with Cht in orbital and head and neck tumours and inthe majority of genitourinary tumours, but surgery was first in paratesticular and in the majority of extremity tumours. Results. The 3 patients with stage IV disease died. Of those with localised tumour, 34 (70%) were alive and well 5 years after treatment, 80% stage I, 75% stage II and 61%stage III. One patient died of heart failure, 3 of Cht toxicity and 1 of intereurrent disease. Conclusions. (Abstract truncated at 2000 characters)
Published in DiRROS: 26.01.2024; Views: 124; Downloads: 28
.pdf Full text (177,30 KB)

500.
Can we rely on cancer mortality data? Checking the validity of cervical cancer mortality data for Slovenia
Maja Primic-Žakelj, Vera Pompe-Kirn, Fani Škrlec, Jožica Šelb-Šemerl, 2001, original scientific article

Abstract: Background. Valid inference on cervical cancer mortality is very difficult since - on the basis of death certificates - it is not always possible to distinguish between cervix, corpus and unspecified uterine cancer deaths. Our aim was to estimate the extent to which cervical cancer as the official cause of death reflects the true mortality from cervical cancer in Slovenia. Material and methods. The data on 2245 deaths from cervix, corpus uteri, and uterus-unspecified cancers for the period 1985-1999 were linked to the Cancer Registry of Slovenia database from the mortality database of Slovenia. Results. Officially, in the period 1985-1999, there were 878 cervical cancer deaths. The comparison of these causes of death with the cancer sites registered in the Cancer Registry revealed that they include only 87.7 % patients with a previous diagnosis of cervical cancer. Of 650 corpus uteri cancer deaths, 17.1% of patients were registered to have cervical cancer, and of 717 unspecified uterine cancer deaths, 31.4% were registered. Taking into account the correctly identified cervical cancer cases among cervical cancer deaths and misclassified cervical cancer deaths as corpus uteri and unspecified uterine, the corrected number of deaths would be 1106. Conclusions. When evaluating the impact of cervical cancer mortality from national mortality rates, the stated underestimation should be taken into account. However, this does not hold for some other cancers.
Published in DiRROS: 26.01.2024; Views: 118; Downloads: 33
.pdf Full text (199,95 KB)

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