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Biomedical subjects

A Kaminski

Publications and source records attributed to A Kaminski.

61 records · Page 4Linked to original sources
PubMed1992

Decreased heterotopic osteogenesis in vitamin-D-deficient, but normocalcemic guinea pigs.

The effect of vitamin D deficiency unhampered by hypocalcemia on de novo bone formation was studied in guinea pigs. Heterotopic induction of osteogenesis was evaluated 4 weeks after intramuscular transplantation of allogenic urinary bladder transitional epithelium from vitamin-D-repleted (+D) donors into +D and -D recipients. In -D recipients the frequency of osteogenesis and the amount of induced bone were significantly diminished; induced bone was less mature, scantly cellular woven bone poorly repopulated with bone marrow. No effect of vitamin D deficiency on orthotopic bone growth and on mineralization of orthotopic and heterotopically induced bone was observed. It is proposed that in addition to inducing factors (BMPs, growth factors) which may be responsible for transformation of mesenchymal cells to osteoprogenitor cells, normal concentrations of 1,25-(OH)2D3 may be required for proliferation and further differentiation of these cells into osteoblasts and for expression of genes engaged in extracellular matrix formation and maturation.

Alkaline Phosphatase↗
PubMed1990

Initiation of encephalomyocarditis virus RNA translation: the authentic initiation site is not selected by a scanning mechanism.

The authentic initiation site on encephalomyocarditis virus (strain R) RNA is the 11th AUG codon (at nt. 834) from the 5' end of the viral RNA, the downstream of the two AUGs in the sequence....ACGAUGAUAAUAUGGCC... In order to assess the role of ribosome scanning in the selection of the correct initiation site, transcripts of a construct comprising the viral 5' noncoding sequence fused to a reporter gene were translated in vitro and the relative frequency of initiation at these two AUG codons, AUG-10 and AUG-11, was assayed. When deletions from the 5' end were made that retained less than 100 nucleotides of the viral 5'-noncoding sequence, initiation was highly cap-dependent and AUG-10 was utilized in preference to AUG-11, consistent with the scanning ribosome model. On the other hand, when the constructs included the entire 574 nt. segment of the 5' noncoding region situated between the poly(C) tract of the virion RNA and nt. 834, initiation was cap-independent and occurred exclusively at AUG-11, with negligible use of AUG-10. These results suggest that structural features of the 574 nucleotide segment cause initiating ribosomes to bind directly to AUG-11, without scanning the immediate upstream sequences that include AUG-10.

Base Sequence↗
PubMed1990

The novel mechanism of initiation of picornavirus RNA translation.

The initiation of translation of picornaviral RNAs takes place by an unusual mechanism whereby ribosomes bind directly to an internal site rather than scan the RNA from the 5'-end. This internal entry mechanism requires a 450-nucleotide segment of the picornavirus 5'-untranslated region. The ribosome binds initially to a site at the 3'-end of this segment, and then may scan the RNA to reach the authentic initiation site. This novel mechanism may be of relevance to the translation of some cellular mRNAs.

Base Sequence↗
PubMed1975

A vision care module within a prototype HMO.

The Health Maintenance Organization (HMO) concept is dedicated to the prevention of disease and disability. Organizations incorporating this concept must include vision care if complete service is to be offered. Described in this paper is one such HMO, Group Health Cooperative of Puget Sound, with details of the successful integration of optometric vision care into this medically oriented, multidisciplinary setting.

Health Maintenance Organizations↗
PubMedDate not supplied

Dating of palaeoanthropological nuragic skeletal tissues using electron paramagnetic resonance (EPR) spectrometry.

Dating of skeletons of Nuragic population living in Sardinia island centuries BP, based on the quantitative evaluation of the concentration of stable paramagnetic species produced by ionising radiation in tooth enamel was performed by using EPR spectrometry. Applying the additive dose method (60Co gamma rays) and comparative calculations based on analogous measurements done with Roman skeleton of the known age as discovered close to Nuragic tomb (Tombs of Giants, La Testa S. Teresa di Gallura, Sardinia) the age of Nuragic skeleton was evaluated as equal to about 3,200 years (1,200 years BC). The total error of EPR measurements and dose extrapolation was estimated for 10-12%. Crystallinity of bone mineral in Nuragic skeleton evaluated by the EPR technique, adapted earlier by some of the authors of the present paper for biomedical studies on mineralised tissues, is only little changed after the centuries of its deposition in the tomb when compared with contemporary bone tissue. Comparison of chemical composition of Nuragic skeleton contaminated through slow percolation by rain of floods with that of contemporary bone sample shows the increase of the concentration of Fe, PO4, SiO2, Al and Mg, Fe, SiO2, AP are not present in contemporary bones. As expected, the contamination was minimal in tooth enamel.

Bone Density↗