Biomedical subjects

I Kuchar

Publications and source records attributed to I Kuchar.

11 recordsLinked to original sources

PubMed2003

[Sonographical breast biopsy: how many core biopsy specimens are needed?].

PURPOSE: To determine the optimum number of specimens of a sonographically guided core biopsy of the breast. MATERIALS AND METHODS: From January 2001 to April 2001, sonographically guided core biopsies (coaxial needle: 11 G; core needle: 12 G) were performed on 106 patients with 115 BI-RADS trade mark 4-5 lesions that had corresponding sonographic findings. Five specimens were obtained in anteroposterior direction parallel to the chest wall and each specimen examined histologically. RESULTS: A total of 575 core biopsies produced 545 specimens (94.8 %), with no material obtained in 30 biopsies (5.2 %). The first and second specimen confirmed the diagnosis in 99 of 115 lesions (86 %), with subsequent specimens confirming the diagnosis in 87 % (3 rd specimen), 88 % (4 th specimen) and 82 % (5 th specimen). The additive accuracy of the five core breast specimens was 86 %, 96 %, 98 %, 99 % and 100 %. The possible volume of 78.9 mm 3 as determined by the sample notch of the core needle only furnished an average volume of 38.1 mm 3 (41.1 mm 3 for the 1 st, 40.1 mm 3 for the 2 nd, 37.5 mm 3 for the 3 rd, 36.7 mm 3 for the 4 th and 35.0 mm 3 for 5 th core specimen). CONCLUSION: Sonographically guided core breast biopsy (coaxial needle: 11 G; core needle: 12 G) may require five passes to achieve a diagnostic accuracy of more than 99 %.

Adult↗

PubMed2003

[Film-screen mammography versus digital storage plate mammography: hard copy and monitor display of microcalcifications and focal findings--a retrospective clinical and histologic analysis].

PURPOSE: A retrospective clinical-histological study to determine the diagnostic accuracy of mammography using conventional screen-film cassettes (hard copy), high-resolution digital phosphor storage plates (hard copy) and monitor display (soft copy) for microcalcifications and focal lesions (BI-RADS (TM) category 4 or 5). MATERIALS AND METHODS: From April to November 2001, 76 patients underwent conventional film-screen mammography and, after diagnosis and preoperative wire localization, digital mammography with the same exposure parameters. Five investigators retrospectively determined the diagnosis after the operation from randomly distributed mediolateral views (hard-copy reading) and from the monitor display (soft-copy reading). These results were correlated with the final histology. RESULTS: The accuracy of conventional screen-film mammography, digital mammography and monitor-displayed mammography was 67%, 65% and 68% for all findings, (n = 76), 59%, 59% and 68% for microcalcifications (n = 44) and 75%, 72% and 63% for focal lesions (n = 32). The overall results showed no difference. CONCLUSION: Our findings indicate equivalence of conventional screen-film mammography, high-resolution digital phosphor storage plate mammography and monitor-displayed mammography.

Adenocarcinoma↗

PubMed2002

[Experiences with phantom measurements in different mammographic systems].

PURPOSE: Determination of image quality between conventional film screen system, digital phosphor storage plate mammography (high resolution) and digital mammography. MATERIALS AND METHODS: Mammograms of the Wisconsin Mammographic Random Phantom, Model 152 A (Radiation Measurements Inc., Wisconsin) were acquired using a conventional film-screen system, a digital storage phosphor plate system and a digital system. RESULTS: Of 225 possible details, 191/a 38.2, 193/a 38.6, and 202/a 40.4 details were detected with conventional film-screen system, digital phosphor storage plate mammography and digital mammography, respectively. There was no significant difference (p < 0,058). The entrance surface air kerma was 9.64 mGy, 7.60 mGy and 7.02 mGy, respectively. CONCLUSIONS: Based on these results, conventional film-screen system can be replaced with both digital phosphor storage plate mammography and digital mammography, to be confirmed with further clinical trials.

Female↗

PubMed2001

Stimulation of intracellular sphingosine-1-phosphate production by G-protein-coupled sphingosine-1-phosphate receptors.

Recently, a family of G-protein-coupled receptors named endothelial differentiation gene (Edg) receptor family has been identified, which are specifically activated by the two serum lipids, sphingosine-1-phosphate and lysophosphatidic acid. Sphingosine-1-phosphate can also act intracellularly to release Ca2+ from intracellular stores. Since in several cell types, G-protein-coupled lysophosphatidic acid or sphingosine-1-phosphate receptors mobilize Ca2+ in the absence of a measurable phospholipase C stimulation, it was analysed here whether intracellular sphingosine-1-phosphate production was the signalling mechanism used by extracellular sphingosine-1-phosphate for mobilization of stored Ca2+. Sphingosine-1-phosphate and the low affinity sphingosine-1-phosphate receptor agonist, sphingosylphosphorylcholine, induced a rapid, transient and nearly complete pertussis toxin-sensitive Ca2+ mobilization in human embryonic kidney (HEK-293) cells. The G-protein-coupled sphingosine-1-phosphate receptors, Edg-1, Edg-3 and Edg-5, were found to be endogenously expressed in these cells. Most interestingly, sphingosine-1-phosphate and sphingosylphosphorylcholine did not induce a measurable production of inositol-1,4,5-trisphosphate or accumulation of inositol phosphates. Instead, sphingosine-1-phosphate and sphingosylphosphorylcholine induced a rapid and transient increase in production of intracellular sphingosine-1-phosphate with a maximum of about 1.4-fold at 30 s. Stimulation of sphingosine-1-phosphate formation by sphingosine-1-phosphate and sphingosylphosphorylcholine was fully blocked by pertussis toxin, indicating that extracellular sphingosine-1-phosphate via endogenously expressed G(i)-coupled receptors induces a stimulation of intracellular sphingosine-1-phosphate production. As sphingosine-1-phosphate- and sphingosylphosphorylcholine-induced increases in intracellular Ca2+ were blunted by sphingosine kinase inhibitors, this sphingosine-1-phosphate production appears to mediate Ca2+ signalling by extracellular sphingosine-1-phosphate and sphingosylphosphorylcholine in HEK-293 cells.

Calcium Signaling↗

PubMed1999

Role of sphingosine kinase in Ca(2+) signalling by epidermal growth factor receptor.

Contribution of sphingosine kinase (SPK)-catalyzed production of sphingosine-1-phosphate (SPP), in comparison to phospholipase C (PLC), to Ca(2+) signalling by epidermal growth factor (EGF) was studied in two HEK-293 cell clones (HEK2 and HEK3), expressing functional EGF receptors and exhibiting release of stored Ca(2+) by intracellular SPP. In HEK3 cells, EGF increased [Ca(2+)](i) and stimulated both, SPK and PLC. [Ca(2+)](i) increase, but not PLC stimulation, was strongly reduced by SPK inhibition. In HEK2 cells, EGF similarly stimulated PLC, but did not increase [Ca(2+)](i) or stimulate SPK, suggesting that intracellular SPP production plays a major role for Ca(2+) signalling by EGF in HEK-293 cells.

Calcium Signaling↗

PubMed1987