Translation,cross-cultural adaptation and validation of the Bulgarian version of the Dizziness Handicap Inventory

Purpose

The aim of the present study was the translation, cross-cultural adaptation and validation of the Dizziness Handicap Inventory in Bulgarian language (DHI-BG).

Methods

Ninety-seven vestibular patients (19 men and 78 women, mean age 45.08 ± 13.85 years) took part in the investigation. All participants were asked to fill in the DHI-BG. Internal consistency was estimated using Cronbach’s alpha and item-total correlation, reproducibility by calculating Bland–Altman’s limits of agreement and intraclass correlation coefficients (ICCs). Associations were estimated by Spearman’s correlation coefficients.

Results

The Cronbach’s alpha for the total score, functional, physical and emotional subscales of DHI-BG were 0.88, 0.75, 0.72 and 0.81. The floor and ceiling effects of the DHI-BG total scale were evaluated with respect to the limits of agreement which were ±9.4–14.53 points. Intraclass correlation coefficients (ICCs) for all scale and subscales were higher than the recommended value of 0.75 and determined good test–retest reliability. The range of items correlation for DHI-BG was from 0.27 (item 12) to 0.72 (item 3). No significant differences were observed in the Cronbach’s alpha coefficients between the DHI-BG and the original version, the German and Italian versions of the questionnaire. The most significant difference was observed in comparison with the German version of DHI. Construct validity presented a moderate correlation between Romberg coefficients and DHI-BG scores and strong correlation between all scores of DHI and the self-perceived disability. The results suggest that DHI-BG scores show a good discriminative validity between groups with different levels of self-assessed disability.

Conclusion

The Bulgarian version of the DHI is a reliable and valid tool in assessing the impact of dizziness on the quality of life in Bulgarian vestibular patients.     

Ile<Superscript>105</Superscript>Val <Emphasis Type="Italic">GSTP1</Emphasis> polymorphism and susceptibility to colorectal carcinoma in Bulgarian population

Background and aims Etiologically, the sporadic colorectal cancer (CRC) is a complex and multifactorial disease that is linked to both exogenic and endogenic factors. Accumulating evidence indicates that susceptibility to cancers, including CRC, is mediated by genetically determined differences in the effectiveness of detoxification of potential carcinogens. A member of the glutathione-S-transferase (GST) family, GSTP1, is an important candidate for involvement in susceptibility to carcinogen-associated CRC. An A→G transition in exon 5 of the GSTP1 gene resulting in Ile¹⁰⁵Val amino acid substitution has been identified. This change leads to alteration in catalytic efficiency of variant enzyme. The aim of the current study was to evaluate the influence of Ile¹⁰⁵Val GSTP1 polymorphism on susceptibility to CRC. Materials and methods The GSTP1 genotyping was conducted in a case-control study of 80 ethnic Bulgarian CRC patients and 126 unaffected controls using polymerase chain reaction restriction fragment length polymorphism method. Results A statistically significant case-control difference in genotype frequencies was observed: 0.69 vs 0.54 for Ile/Ile, 0.22 vs 0.39 for Ile/Val, and 0.09 vs 0.07 for Val/Val (p = 0.049). The odds ratio (OR) for Val/Val was close to 1 (0.96, 95%CI: 0.35–2.66, p = 0.942), whereas the OR for Ile/Val was significantly lower, 0.45 (95%CI: 0.24–0.86, p = 0.016), compared to the referent Ile/Ile genotype. Although a prevalence of the GSTP1 variant allele-containing genotypes (Ile/Val or Val/Val) was found in controls than in patients (OR = 0.53, 95%CI: 0.30–0.96, p = 0.035), the allele frequencies did not show significant difference between cases and controls (p = 0.127). Conclusions Based on the obtained protective effect of Ile/Val GSTP1 genotype, we could suggest that Ile¹⁰⁵Val GSTP1 polymorphism may play some role in susceptibility to CRC.     

The prognostic value of preoperative serum levels of IL‐12p40 and IL‐23 for survival of patients with colorectal cancer

Colorectal cancer (CRC) patients were previously shown to express a signature of cytokines that contribute to cancer pathogenesis and are detectable in serum. The aim of this study was to evaluate the potential clinical use of circulating cytokine measurements in CRC patients preoperatively as markers for disease outcome. The levels of cytokines IL‐12p40 and IL‐23 were assessed by ELISA in the sera of 91 patients with previously untreated CRC and then 5‐year survival was determined using Kaplan–Meier analyses. The levels of circulating interleukin IL‐12p40 significantly decreased with the progression of CRC, whereas the levels of IL‐23 remained with no significant differences between disease stages. None of the cytokine levels were influenced by age, gender and colon vs rectum localization. We found that preoperative serum concentration of IL‐12p40 cytokine is a good prognostic marker for survival; as for IL‐23 levels, we found no outcome prognostic value. In addition, 5‐year survival confirmed that tumor grade, bowel wall invasion, lymph node and metastatic status have an impact on overall survival. In conclusion, we believe that our findings show clinical significance of the preoperative serum concentration for IL‐12p40 and provide an additional prognostic biomarker for CRC survival.     

C3 binding glycoprotein from Cuscuta europea induced different cytokine profiles from human PBMC compared to other plant and bacterial immunomodulators

The immunomodulatory properties of bioactive agents include the ability to induce cytokine production by the activated target cell. The effect of immunomodulatory C3 binding glycoprotein isolated from Cuscuta europea on the induction of human PBMC cytokine synthesis and the cell viability was investigated. Isolated PBMC from healthy donors were cultured for 24 h with C3bgp. We also studied the influence of C3bgp on the cytokine production in LPS, PHA, PWM and Dex treated PBMC. The quantitative determination of TNF-alpha, IL-12, IL-6 and IL-10 was performed in culture supernatant by ELISA. Results obtained demonstrated that C3bgp induced proinflammatory and immunoregulatory cytokine production, in the highest degree IL-12, followed by IL-6 and in lower degree TNF-alpha. IL-12 quantity was significantly increased in C3bgp stimulated cultures in comparison with LPS, PHA and PWM stimulated PBMC. C3bgp also increased IL-12 in PHA or PWM stimulated cultures, but not in LPS stimulated culture. C3bgp significantly increased IL-6 production compared to the PHA and PWM but not to LPS stimulation. On the other side, C3bgp inhibited IL-10 production after LPS, PHA and PWM stimulation. Cell viability in C3bgp stimulated cultures retained on the same level from 72 to 120 h of culturing, in contrast to LPS and PHA stimulated cultures. Based on the results presented, we conclude that the C3bgp exhibited immunomodulatory properties on the human PBMC. The ability of PDTC and Dex to down-regulate the effect of C3bgp on the proinflammatory cytokine production suggests that a part of the mechanism of action of C3bgp is mediated through NF-kB signal transduction pathway.     

Functional genetic polymorphisms in interleukin-12B gene in association with systemic lupus erythematosus

Genetic polymorphisms in cytokine genes, which influence gene expression, may have an important impact on SLE susceptibility and severity. The aim of this study was to examine the possible influence of two functional polymorphisms in cis-regulatory regions of IL12B gene in the susceptibility and clinical symptoms of SLE in Bulgarian patients. Female SLE patients (n = 141) and 124 healthy women were included in the study. Genotyping for the IL12B A/C polymorphism in 3′UTR was performed by restriction fragment length polymorphisms PCR assay and for the IL12Bpro polymorphism by allele-specific PCR. Genotype-22 of IL12Bpro polymorphism was overrepresented among women with SLE (28 vs. 17%; OR = 1.875; 95% CI: 1.037 ÷ 3.390; P = 0.037). Respectively, a higher frequency of allele-2 was found in patients than in controls (51% vs. 40%; OR = 1.566; 95% CI: 1.110 ÷ 2.210; P = 0.011). Also, we found significantly elevated frequency of genotype-22 of IL12Bpro polymorphism among SLE patients who were simultaneously carrier of genotype-AA of SNP in 3′UTR. Women with both homozygous genotypes, genotype-AA of SNP in 3′UTR and genotype-22 of IL12Bpro polymorphism, had a 2.1-fold significantly elevated risk for SLE development. The carrying of genotype-11 of IL12Bpro polymorphism was positively associated with hematological and neuropsychiatric manifestations of SLE. We have provided evidence that the IL12Bpro polymorphism was associated with SLE development among Bulgarian women. Although a strong individual effect of SNP in 3′UTR of IL12B was not detected, we found that genotype-22 of IL12Bpro was predominantly combined with genotype-AA of SNP in 3′UTR among SLE patients and this combination elevates the risk of SLE.     

Interleukin-12B-3'UTR polymorphism in association with IL-12p40 and IL-12p70 serum levels and silicosis severity

Susceptibility to silicosis and to disease severity is in part genetically determined. In this study, the role of IL-12B-3'UTR polymorphism in susceptibility and severity of silicosis and its influence on IL-12p40 and IL-12p70 serum level were investigated. The quantity of IL-12p40 and IL-12p70 was detected by enzyme-linked immunosorbent assay and the genotype of IL-12B was determined using the polymerase chain reaction-restriction fragment-length polymorphism method. We observed elevated IL-12p40 in contrast to IL-12p70 serum levels in a group of 62 silicosis patients compared with both control groups. In severe silicosis patients, we detected the highest IL-12p40 serum levels (129.1 +/- 67.7 pg mL(-1)); lower in patients with the moderate (94 +/- 41.6 pg mL(-1)), whereas in mild silicosis, the IL-12p40 levels (67 +/- 23.5 pg mL(-1)) was similar to these in healthy donors. According to IL-12B polymorphism, increased serum levels were observed in subjects with AA genotype (103.2 +/- 46.9 pg mL(-1)) compared to silicosis patients with AC genotype (82.7 +/- 38.3 pg mL(-1)). No significant differences of genotype and allele frequencies of the 3'UTR polymorphism were observed between silicosis patients and healthy controls. However, the heterozygous genotype was found approximately five times more frequently in patients with mild and moderate (48% and 52%) silicosis compared to patients with severe silicosis (11%), and that IL-12B polymorphism may contribute to silicosis severity rather than to susceptibility. Our data demonstrated that elevated serum IL-12p40, independently of IL-12p70 levels, is associated with severity of silicosis, and suggested that IL-12p40 profibrotic activity may contribute to silicosis severity.