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A Koppel

Publications and source records attributed to A Koppel.

6 recordsLinked to original sources
PubMed2001

Application of strengths, weaknesses, opportunities and threats analysis in the development of a health technology assessment program.

There has been recent interest in developing a health technology assessment (HTA) function in Estonia. A group of individuals knowledgeable about HTA in Canada, Germany, Romania and Spain, along with representatives of the University of Tartu, Estonia, was convened by the Institute of Health Economics in Edmonton, Canada, to consider options for such a function. In a one-day workshop strengths, weaknesses, opportunities and threats (SWOT) analyses of HTA were conducted, first at a 'global' level, and then of the Estonian situation. The 'global' SWOT analysis yielded a large number of items that pertain to institutionalized HTA in a generic sense, i.e. not based on any individual HTA agency. The 'Estonian' SWOT yielded a subset of items, which pertain to development of HTA in that country. Ten actionable steps were then developed on the basis of this subset, which could be used to initiate the creation of an HTA body in Estonia.

Delivery of Health Care↗
PubMed2000

Decrease in striatal enkephalin mRNA in mouse models of Huntington's disease.

Huntington's disease is a devastating progressive neurodegenerative illness characterized by massive neuronal loss in the striatum. It is caused by the presence of an expanded CAG repeat in the gene encoding huntingtin, a protein of unknown function. We have examined the expression of neurotransmitters and other antigens present in striatal neurons with immunohistochemistry, and the level of expression of mRNAs encoding enkephalin, substance P, and glutamic acid decarboxylases with quantitative in situ hybridization histochemistry, in the striatum of two mouse models of Huntington's disease: transgenic animals expressing exon 1 of the human huntingtin gene with 144 CAG repeats and "knock-in" mice containing a chimeric mouse/human exon 1 with 71 or 94 CAG repeats inserted by homologous targeting. Although the transgenic (but not the knock-in) mice were previously shown to display prominent huntingtin- and ubiquitin-containing nuclear inclusions in striatal neurons, in situ nick translation followed by emulsion autoradiography did not reveal any DNA damage in striatum or cortex in these mice. Immunolabeling for calbindin D 28K, enkephalin, substance P, glutamic acid decarboxylases (M(r) 65,000 or 67,000, GAD65 and GAD67), somatostatin, choline acetyltransferase, parvalbumin, and glial fibrillary acidic protein were remarkably similar in transgenic, knock-in, and wild-type mice. Both transgenic and knock-in mice, however, showed a marked decrease in the level of expression of enkephalin mRNA in striatal neurons without significant decreases in mRNAs encoding substance P, GAD65, or GAD67. The data indicate that decreased expression of enkephalin mRNA may be an early sign of neuronal dysfunction due to the Huntington's disease mutation.

Animals↗
PubMed1999

Enhanced sensitivity to N-methyl-D-aspartate receptor activation in transgenic and knockin mouse models of Huntington's disease.

We used two mouse models of Huntington's disease (HD) to examine changes in glutamate receptor sensitivity and striatal electrophysiology. One model, a transgenic, consisted of mice expressing exon 1 of the human HD gene and carrying 141-157 CAG repeat sequences (R6/2 line). The second model, a CAG repeat "knockin," consisted of mice with different lengths of CAG repeats (CAG71 and CAG94 repeats). The effects of glutamate receptor activation were examined by visualizing neurons in brain slices with infrared videomicroscopy and differential interference contrast optics to determine changes in somatic area (cell swelling). Striatal and cortical neurons in both models (R6/2 and CAG94) displayed more rapid and increased swelling to N-methyl-D-aspartate (NMDA) than those in controls. This effect was specific as there were no consistent group differences after exposure to alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) or kainate (KA). Intracellular recordings revealed that resting membrane potentials (RMPs) in the R6/2 transgenics were significantly more depolarized than those in their respective controls. RMPs in CAG94 mice also were more depolarized than those in CAG71 mice or their controls in a subset of striatal neurons. Confirming previous results, R6/2 mice expressed behavioral abnormalities and nuclear inclusions. However, CAG71 and CAG94 knockins did not, suggesting that increased sensitivity to NMDA may occur early in the disease process. These findings imply that NMDA antagonists or compounds that alter sensitivity of NMDA receptors may be useful in the treatment of HD.

Animals↗
PubMed1975

[Comparison of nutrient media for isolation of microflora in swine dysentery].

The usability of five nutrient media - three kinds of spirolate media, thioglycolate medium and brain hearth medium - suitable for the isolation of Vibrio coli and germs similar to borrelia isolated from pigs affected by dysentery, and vibria isolated from cattle, was compared in the study. The results of comparison show that fresh-prepared substrates must be used bor the isolation of the mentioned germs in all cases and a corresponding medium must be provided. The modified spirolate media prepared from inland and imported ingredients were suitable for the isolation of the mentioned microorganisms even in the case of their use as selective media after enrichment with antibiotics. The spirolate media and thioglycolator agar were not found suitable for maintaining the strains of germs similar to borrelia due to the quick production of involution forms and the result dying of the strains. Thenutrient solution prepared as the brain hearth inf. Oxoid blood agar is very suitable for the isolation as well as maintenance of strains.

Animals↗
PubMedDate not supplied

Thermoradiotherapy for superficial tumour deposits in the head and neck.

Tumour deposits in the head and neck region were treated with hyperthermia using 915 MHz external microwave applicators and radiation therapy between 1986 and 1990. The mean (+/- SE) radiation dose was 47 +/- 2 Gy (range 21-77 Gy). All but four patients had failed previous therapy. Mean tumour volume was 40 +/- 10 cm3 (range 0.3-276 cm3). Hyperthermia was administered biweekly in 80% of the patients in 6.0 +/- 0.4 sessions (range 1-10); thermometry involved 3.6 +/- 0.4 catheters (range 1-9) and 5.7 +/- 0.4 sensors (range 1-12) per tumour. Of the 50 lesions evaluable for response, 29 had a complete response (58%), and 20 had a partial response (40%). Lesions were stratified by depth. In tumours considered potentially heatable (i.e. depth < or = 3 cm and lateral dimensions at least 2 cm less than boundary of applicator), the complete response rate was 81% (26/32, 47 +/- 2 Gy, 15 +/- 3 cm3); whereas for patients with tumours deeper than 3 cm, the complete response rate was 17% (3/18, 48 +/- 3 Gy, 110 +/- 21 cm3), p = 0.0001. Among lesions < or = 3 cm depth that exhibited a complete response, six recurred (24%, 5.8 +/- 1.8 months) while 20 lesions were recurrence free at last follow-up of 11.9 +/- 1.2 months). The overall survival of patients with lesions < or = 3 cm depth was 11.5 +/- 1.3 months (range 2.4-32.3 months) while for patients with lesions > 3 cm depth survival was 6.7 +/- 0.9 months (range 2.1-18.6 months), p = 0.01. In superficial lesions with depth < or = 3 cm, multivariate logistic regression analysis indicated that the model best correlating with complete response included radiation dose (p = 0.08) and tumour volume (p = 0.08, model p = 0.004). Multivariate proportional hazard analysis indicated that the model best correlating with duration of local control included tumour depth (p = 0.03) and previous radiation therapy (p = 0.08, model p = 0.006). Twenty-two fields were treated without any skin reactions (39%), 23 evidenced erythema (40%) and eight thermal blistering (14%). Ulceration occurred in 11 treatment fields but in all but one of these cases the ulceration may have been due to tumour breakdown as there was direct invasion of the skin by tumour prior to the initiation of treatment. The maximal skin temperature was the best predictor of morbidity although the correlation was not statistically significant (p = 0.19).

Adenocarcinoma↗