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Povzetek: Background. Like all breast imaging modalities MRI has limited specificity and the positive predictive value for lesions detected by MRI alone ranges between 15 and 50%. MRI guided procedures (needle biopsy, presurgical localisation) are mandatory for suspicious findings visible only at MRI, with potential influence on therapeutic decision. The aim of this retrospective study was to evaluate our initial clinical experience with MRI-guided vacuum-assisted breast biopsy as an alternative to surgical excision and to investigate the outcome of MRI-guided breast biopsy as a function of the MRI features of the lesions. Patients and methods. In 14 women (median age 51 zears) with 14 MRI-detected lesions, MRI-guided vacuum-assisted breast biopsy was performed. We evaluated the MRI findings that led to biopsy and we investigated the core and postoperative histology results and follow-up data. Results. The biopsy was technically successful in 14 (93%) of 15 women. Of 14 biopsies in 14 women, core histology revealed 6 malignant (6/14, 43%), 6 benign (6/14, 43%) and 2 high-risk (2/14, 14%) lesions. Among the 6 cancer 3 were invasive and 3 were ductal carcinoma in situ (DCIS). The probability of malignancy in our experience was higher for non-mass lesion type and for washout and plateau kinetics. Conclusions. Our initial experience confirms that MRI-guided vacuum-assisted biopsy is fast, safe and accurate alternative to surgical biopsy for breast lesions detected at MRI only.
Objavljeno v DiRROS: 21.03.2024; Ogledov: 59; Prenosov: 26
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Povzetek: The complementary prism of a graph $\Gamma$ is the graph $\Gamma \overline{\Gamma}$, which is formed from the union of $\Gamma$ and its complement $\overline{\Gamma}$ by adding an edge between each pair of identical vertices in $\Gamma$ and $\overline{\Gamma}$. Vertex-transitive self-complementary graphs provide vertex-transitive complementary prisms. It was recently proved by the author that $\Gamma \overline{\Gamma}$ is a core, i.e. all its endomorphisms are automorphisms, whenever $\Gamma$ is vertex-transitive, self-complementary, and either $\Gamma$ is a core or its core is a complete graph. In this paper the same conclusion is obtained for some other classes of vertex-transitive self-complementary graphs that can be decomposed as a lexicographic product $\Gamma = \Gamma_1 [\Gamma_2]$. In the process some new results aboutthe homomorphisms of a lexicographic product are obtained.
Ključne besede: graph homomorphism, core, complementary prism, self-complementary graph, vertex-transitive graph, lexicographic product
Objavljeno v DiRROS: 19.03.2024; Ogledov: 57; Prenosov: 35
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Objavljeno v DiRROS: 15.03.2024; Ogledov: 92; Prenosov: 30
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Povzetek: Background. Various electrofusion parameters have to be adjusted to obtain theoptimal electrofusion efficiency. Based on published data, good electrofusion conditions can be achieved with the hypotonic treatment. However, the duration of the hypotonic treatment before electroporation and buffer hypoosmolarity have to be adjusted in order to cause cell swelling, to avoid regulatory volume decrease and to preserve cell viability. The aims of our study were to determine cell size dynamics and viability of four different cell lines in hypotonic buffer and to study the influence of the electroporation on the selected cell line in hypotonic buffer. Materials and methods. Cell size dynamics of different cell lines exposed to hypotonic buffer and electroporation were analyzed by time-resolvedcell size measurements. The viability of hypotonically treated oržand electroporated cells was determined 24 h after the experiment by a modified crystal violet (CV) viability assay. Results. In our experimental conditions the hypotonic treatment at 100 mOsm was efficient for CHO, V79 and B16-F1 cell lines. The optimal duration of the treatment was between two and five minutes. On the other hand the same hypotonic treatment did not cause cell swelling of NS1 cells. Cell swelling was also observed after electroporation of B16-F1 in isotonic buffer and it was amplified when hypotonic buffer was used. In addition, the regulatory volume decrease was successfully inhibited with electroporation. Conclusions. Cell size dynamicsin hypotonic conditions should be studied for each cell line since they differ in their sensitivity to the hypotonic treatment. The inhibition of cell regulatory volume decrease by electroporation may be beneficial in achieving higher electrofusion efficiency. (Abstract truncated at 2000 characters)
Ključne besede: hypotonic treatment, cell swelling, regulatory volume decrease, cell size measurements, viability, electrofusion, electroporation
Objavljeno v DiRROS: 08.03.2024; Ogledov: 111; Prenosov: 32
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Povzetek: Background. Transient hypocalcemia is the most common complication after thyroidectomy. Normomagnesemia is needed for normal secretion of PTH and end-organ responsiveness. Our aim was to determine the influence of infusion of magnesium sulphate before thyroidectomy on the incidence of laboratory and clinical transient hypocalcemia. Methods. In our prospective study, 48 patients (5 men, 43 women; age 22-73 years, median 45 years), who underwent total or near-total thyroidectomy, were randomised preoperatively. Half of them received intravenously 4 ml of 1M magnesium sulphate at the beginning of the surgical procedure, the other half were the control group. Serum concentrations of calcium, ionised calcium, magnesium, phosphate, albumin and PTH were measured prior to surgery and on the first day after surgery. Results. Laboratory postoperative hypocalcemia was present in 27% of patients and 23% of patients had clinical signs and/or symptoms of postoperative hypocalcemia. The concentration of total calcium (p=0.024) and of albumin (p=0.01) was lower in the group that received magnesium sulphate. Conclusions.The patients who received infusion of magnesium sulphate before total thyroidectomy had lower concentration of total serum calcium and albuminin comparison to the control group. There was no statistical differencein the incidence of clinical transient hypocalcemia.
Objavljeno v DiRROS: 08.03.2024; Ogledov: 85; Prenosov: 25
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