Ana Zekovic

Validation of Serbian version of UCLA Scleroderma Clinical Trial Consortium Gastrointestinal Tract Instrument in 104 patients with systemic sclerosis

Gastrointestinal (GI) involvement is the leading cause of morbidity with great impact on health-related quality of life (HRQOL) in patients with systemic sclerosis (SSc). The UCLA-GIT 2.0 is a disease-specific HRQOL instrument for the assessment of GI symptoms severity in patients with SSc. We evaluated reliability and validity of the Serbian version of UCLA-GIT 2.0 by assessing association of GI involvement and other disease manifestations in patients with SSc. UCLA-GIT 2.0 was adapted into Serbian and administered to 104 patients with SSc who had previously completed the SF-36 questionnaire. We evaluated the internal consistency reliability and associations between the UCLA-GIT 2.0 and SF-36 scales. Data from patients’ medical history were reviewed for other disease manifestations. UCLA-GIT 2.0 had acceptable reliability (defined as Cronbach’s alpha >0 .69) and the majority of hypothesized correlations with SF-36 scale scores were of moderate magnitude (coefficient ≥ 0.30). Active disease and pulmonary fibrosis were associated with higher GIT Total scale score (p < 0.05). Distension mostly correlated with HRQOL impairment (r = 0.70, p < 0.001). The Serbian version of the UCLA-GIT 2.0 questionnaire has acceptable reliability and validity for the assessment of GI involvement in patients with SSc. GI impairment is very frequent in patients with active SSc, as well in those with pulmonary fibrosis.

Knots in Art

We analyze applications of knots and links in the Ancient art, beginning from Babylonian, Egyptian, Greek, Byzantine and Celtic art. Construction methods used in art are analyzed on the examples of Celtic art and ethnical art of Tchokwe people from Angola or Tamil art, where knots are constructed as mirror-curves. We propose different methods for generating knots and links based on geometric polyhedra, suitable for applications in architecture and sculpture.

Expression of TLR7 , TLR9 , JAK2 , and STAT3 genes in peripheral blood mononuclear cells from patients with systemic sclerosis

Systemic sclerosis (SSc) is a rare, chronic, multisystem autoimmune disease clinically characterized by progressive fibrosis of the skin and internal organs. The basic mechanism appears to involve endothelial cell injury, overproduction of extracellular matrix proteins, and aberrant immune activation. So far, there have been a few attempts to find genetic biomarkers for monitoring disease activity or for correlation with certain symptoms. In order to reveal reliable biomarkers, we analyzed the expression of four genes representing three important signaling pathways, TLR7, TLR9, and JAK2-STAT3. Using RT-qPCR technique, we analyzed the expression of TLR7, TLR9, JAK2, and STAT3 genes in peripheral blood mononuclear cells of 50 SSc patients and 13 healthy individuals. We detected significant upregulation of TLR7 gene expression in a group of SSc patients compared to non-SSc group. Receiver operating characteristic (ROC) analysis showed that TLR7 expression efficiently discriminates SSc cases from healthy individuals. High TLR7 expression positively correlated with the late form of disease, active SSc, and the presence of digital ulcers. Decreased levels of TLR9 and JAK2 mRNA were found in the patient’s cohort in comparison to non-SSc individuals, but showed no correlation with specific clinical outcomes. The expression level of the STAT3 gene did not differ between the analyzed groups. This is the first study on the expression of TLR7, TLR9, and STAT3 genes in SSc patients. Our results show that TLR7, TLR9, and JAK2 genes are potential biomarkers for SSc. The results obtained in this study could contribute to better classification, monitoring, and outcome prediction of patients with SSc based on genetics.

In Memoriam: Slavik Jablan 1952–2015

After a long and brave battle with a serious illness, our dear friend and colleague Slavik Jablan passed away on 26 February 2015. [...]

The efficacy and safety of autologous conditioned serum (ACS) injections compared with betamethasone and placebo injections in the treatment of chronic shoulder joint pain due to supraspinatus tendinopathy: a prospective, randomized, double-blind, controlled study.

AIMS Autologous conditioned serum (ACS; marketed as Orthokine®) is an autologous blood product that has previously shown efficacy in treatment of joint osteoarthritis, spinal radiculopathy, tendon and muscle injuries in randomized controlled trials. In this 24-week, randomized, double-blind study, we compared the efficacy and safety of ACS with glucocorticoid (betamethasone) injections in chronic supraspinatus tendinopathy patients. MATERIAL AND METHODS Thirty-two patients with chronic supraspinatus tendinopathy were enrolled in the study. The ACS group received four ACS injections once weekly over four weeks and the glucocorticoid group received three betamethasone injections once weekly over three weeks with a placebo (saline) injection at week 4 into the enthesis and paratenon of the supraspinatus tendon. Study endpoints were pain intensity (VAS) and Constant Shoulder Score (CSS) assessed at weeks 0, 4 and 24. RESULTS Shoulder pain intensity improved after 4 weeks and significantly improved after 24 weeks in patients treated with ACS compared with those treated with glucocorticoids (pain intensity week 4: ACS=22.0, glucocorticoid=32.0; week 24: ACS=15.0, glucocorticoid=40.0). CSS improved to a similar extent in both groups after 4 weeks. After 24 weeks, ACS patients exhibited significantly greater CSS improvements than glucocorticoid patients. Adverse events (n=8) were reported in betamethasone patients. CONCLUSIONS Compared with betamethasone, ACS therapy improved joint function and reduced shoulder pain more effectively after 4 weeks of treatment; these improvements were sustained to week 24. Combined with its favorable safety profile, ACS appears to be a more effective treatment than glucocorticoids and could enhance the quality of life in patients with chronic rotator cuff tendinopathy.

Association between the -174 C/G polymorphism in the interleukin-6 (IL-6) gene and gastrointestinal involvement in patients with systemic sclerosis

Genetic predisposition to systemic sclerosis (SSc) has still not been fully revealed. Interleukin-6 (IL-6) is a mediator of T cell proliferation and fibrotic events in SSc. Polymorphisms in the IL-6 are found to be important in susceptibility to development of SSc. We aimed to assess the frequency of -174 C/G of IL-6 gene polymorphism in SSc patients and healthy controls, as well as correlation with disease manifestations. In the case-control study, 102 patients with SSc and 93 controls were included. PCR-RFLP method was performed for genotyping promotor variants -174 C/G of IL-6 gene. The expression level of IL-6 was determined by qRT-PCR on subset of 50 patients and 13 healthy controls with different IL-6 genotypes. We used UCLA GIT 2.0 questionnaire to assess gastrointestinal involvement in SSc patients. The expression level of IL-6 gene was significantly higher in patients with SSc in comparison with healthy controls (p < 0.05). Carriers of C-allele of IL-6 gene compared to those with G allele, showed higher expression of IL-6 gene (95.8 vs. 41.2, p < 0.05), higher GIT total score (0.85 vs. 0.5, p < 0.05) and higher distension scale score (1.4 ± 0.9 vs. 0.78 ± 0.8, p = 0.05). No significant differences in genotype distribution and allele frequency were observed between patients and controls. The expression of IL6 gene varies significantly during the course of SSc. The IL-6 gene variant -174 C/G (presence of C-allele) is associated with higher IL-6 gene expression and greater GIT impairment in patients with SSc.

Unknotting and maximum unknotting numbers

We introduce concepts of the maximum unknotting number and the mixed unknotting number, taking into consideration the Bernhard–Jablan Conjecture about computing the unknotting number based only on minimal knot diagrams. The existence of Kauffman knots (alternating knots, such that a crossing change does not change their minimal crossing number) was first suggested by Kauffman. We extend the concept and offer three related classes of knots named: Kauffman knots, Zekovic knots and Taniyama knots.

Smoothing distances of knots

In the existing tables of knot smoothings knots with smoothing number 1 are computed by Abe and Kanenobu [1] for knots with at most n=9 crossings, and smoothing knot distances are computed by Kanenobu [2] for knots with at most n=7 crossings. In this work are computed some undecided knot distances 1 from these papers, and extended the computations by computing knots with smoothing number one with at most n = 11 crossings and smoothing knot distances of knots with at most n= 9 crossings. All computations are done in the program LinKnot, based on Conway notation and non-minimal representations of knots.