Radiologic measurement of cochlea and hearing preservation rate using slim straight electrode (CI422) and round window approach.

Hearing preservation surgery constitutes a considerable branch of cochlear implantation surgery and is being steadily developed and perfected. The aim of the study was to verify if insertion of a cochlear implant electrode according to individually calculated linear insertion depth improves hearing preservation. We evaluated the relations between the size of a cochlea, insertion depth angle, linear insertion depth and hearing preservation rate (HP) according to Hearing Preservation Classification in a retrospective case review of 54 patients implanted with a slim straight electrode Nucleus CI422 in 2008-2011. Group HP was 0.75 at activation, 0.67 at 12 months (for 53 patients) and 0.60 at 24 months. In 53 cases, the mean insertion depth angle was 375° (SD 17°); mean calculated cochlear duct length 35.87 mm (SD 1.95); mean calculated linear insertion depth 23.14 mm (SD 1.68). There was no significantly relevant relation between HP values and angular insertion depth or insertion depth. Preoperative measurements of cochlea and specific parameters such as linear insertion depth have no effect on hearing preservation. Poor hearing preservation in some deep insertion cases cannot be explained entirely by the electrode position.

Malnutrition Risk in Kidney Recipients Treated With Mycophenolate Mofetil Is Associated With IMPDH1 rs2278294 Polymorphism.

BACKGROUND: Malnutrition is known to increase morbidity and mortality in renal transplant recipients, whereas little is known about genetic predisposition to low body mass index (BMI) in the transplant setting. Inosine monophosphate dehydrogenase (IMPDH) regulates intracellular fat accumulation, pre-adipicytes maturation, and is a target of mycophenolic acid (MPA) used as a standard immunosuppressant. We hypothesized that MPA may interfere with fat tissue formation and weight gain in kidney transplant recipients and this process may be modified by IMPDH1 or IMPDH2 (genes encoding constitutive and inducible IMPDH) small nucleotide polymorphism variants. STUDY DESIGN: In an observational longitudinal study of kidney transplant recipients treated with mycophenolate mofetil, genetic factors were IMPDH1 (rs2278294, rs2278293) and IMPDH2 (rs11706052) allelic variants, the main outcome was the time-dependent change in BMI, and secondary outcomes were occurrence of BMI below 18.5 or 20 kg/m2. RESULTS: In a study group of 190 patients, no association was found between BMI changes and rs11706052 and rs2278293 variants. In terms of rs2278294, we found that allele G was associated with significantly slower BMI gain in a dominant model of inheritance. Concerning secondary endpoints, none of the AA carriers were underweight at 6 months post-implantation, while at least 2% of G allele carriers were underweight. From the first post-transplant year, all AA carriers had BMI above 20 kg/m2, while among G allele carriers at least 10% had BMI < 20 kg/m2 by generalized estimating equations. CONCLUSION: Based on our results, we postulate that MPA derivates influence post-transplant BMI and potentially also body fat content. In consequence, genotyping rs2278294 would potentially allow clinicians to personalize MPA treatment.

Fibular aplasia with ectrodactyly--broadening the clinical spectrum.

Fibular aplasia-ectrodactyly is a rare disorder of the central axis, characterized by shortening of the affected limbs and formation of split hand and/or foot. Here we report on a severely affected case of fibular aplasia with ectrodactyly, in which the upper limb malformations are more pronounced than usually described in sporadic cases.

Congenital anomalies and developmental delay in a boy with double chromosome 6 derived supernumerary marker.

The frequency of small supernumerary marker chromosomes has been estimated to approximately 0.45 per 1000 newborns. They are usually seen as single marker chromosomes in a mosaic state. Two cytogenetically identical markers have been observed only occasionally. We report on a boy, with congenital heart defect, neonatal hypotonia, hypogenitalism, delayed psychomotor development and mild dysmorphic facial features. The GTG karyotype performed on peripheral blood lymphocytes revealed a mosaic male karyotype with three cell lines. One cell line had a normal karyotype. In the other two either single or double chromosome 6 derived supernumerary markers were present, leading to partial trisomy or partial tetrasomy of chromosome 6, respectively.

Association of MYH9 rs3752462 and rs5756168 Polymorphisms With Transplanted Kidney Artery Stenosis.

Allelic variants of the MYH9 gene, encoding myosin nonmuscle heavy chain type IIA, have been shown to correlate with diminished glomerular filtration rates and end-stage kidney disease in individuals of Caucasian ancestry. Myosin nonmuscle heavy chain type IIA is expressed during development as well as in injured vessels and kidney structures. We hypothesized that MYH9 risk variants may correlate with kidney artery injury and dysfunctional healing, such as transplant renal artery stenosis (TRAS). Our study aimed at evaluating the association of MYH9 risk allelic variants (rs4821480, rs4821481, rs3752462, rs11089788, rs136211, rs5756168, rs2032487, and rs2239784) with TRAS, defined as >50% renal artery lumen reduction. Genotyping was performed with the use of custom Taqman genotyping assays on DNA samples (n = 295) from white deceased-donor kidney transplant recipients and genomic DNA from the corresponding donors. Statistical analysis was performed with the use of Kaplan-Meier estimates, log-rank tests, and proportional hazard Cox models. Recipients carrying TT in rs5756168 experienced diminished risk of TRAS (hazard ratio [HR], 0.31; P < .009), whereas organs carrying CC in rs3752462 were exposed to excessive TRAS risk (HR, 2.54; P < .047). In multivariate stepwise analysis TRAS was 10.9-fold increased in kidneys originating from rs3752462 CC, whereas the risk was decreased 3.45-fold (adjusted HR, 0.29) in recipients carrying rs5756168 TT (P < .007 and P < .033, respectively). Intracranial bleeding or trauma compared with other mechanisms of donor death diminished TRAS risk by 87% and 91%, respectively (P < .030 and P < .017). Our study is the first to identify genetic predisposition to transplant renal artery stenosis.

Novel sporadic and recurrent mutations in KRT5 and KRT14 genes in Polish epidermolysis bullosa simplex patients: further insights into epidemiology and genotype-phenotype correlation.

Epidermolysis bullosa simplex (EBS) is a hereditary genodermatosis characterised by trauma-induced intraepidermal blistering of the skin. EBS is mostly caused by mutations in the KRT5 and KRT14 genes. Disease severity partially depends on the affected keratin type and may be modulated by mutation type and location. The aim of our study was to identify the molecular defects in KRT5 and KRT14 in a cohort of 46 Polish and one Belarusian probands with clinical suspicion of EBS and to determine the genotype-phenotype correlation. The group of 47 patients with clinical recognition of EBS was enrolled in the study. We analysed all coding exons of KRT5 and KRT14 using Sanger sequencing. The pathogenic status of novel variants was evaluated using bioinformatical tools, control group analysis (DNA from 100 healthy population-matched subjects) and probands' parents testing. We identified mutations in 80 % of patients and found 29 different mutations, 11 of which were novel and six were found in more than one family. All novel mutations were ascertained as pathogenic. In the majority of cases, the most severe genotype was associated with mutations in highly conserved regions. In some cases, different inheritance mode and clinical significance, than previously reported by others, was observed. We report 11 novel variants and show novel genotype-phenotype correlations. Our data give further insight into the natural history of EBS molecular pathology, epidemiology and mutation origin.

Pentoxifylline inhibits perforin-dependent natural cytotoxicity in vitro.

Pentoxifylline (PTX) is commonly used in peripheral blood vessel diseases, however it has also been found to decrease the level of proinflammatory cytokines such as IL-12, TNF-alpha and IFN-gamma. Moreover, some authors reported that PTX suppresses spontaneous cytotoxicity of peripheral blood mononuclear cells (PBMC) in vitro. It could influence the mechanism of killing target cells by PBMC. For this reason we evaluated the influence of PTX on spontaneous cytotoxicity of PBMC against K562 and CaSki cell lines. Subsequently, we compared this effect to that evoked by dexamethasone, one of the most effective anti-inflammatory drugs. Our study revealed that PTX inhibits natural cytotoxicity preferentially through inhibition of perforin-mediated cell membrane damage, without a statistically significant influence on apoptosis induction. Furthermore, pentoxifylline inhibits natural cytotoxicity as effectively as dexamethasone. However, the result of PTX inhibitory influence is observed much earlier than that of dexamethasone. Currently PTX is commonly used in diseases that occur more frequently in elderly patients. We suggest that PTX, inhibiting perforin-dependent PBMC cytotoxic activity, could weaken anti-cancer action of immune system thus accelerating the progress of neoplasm formation in these patients.

Clinical aspects of disrupted Hedgehog signaling (Review).

The Hedgehog (HH) signaling pathway is involved in patterning and development of a variety of organ systems, including the nervous system, the skeletal system, the craniofacial structures, and the gastrointestinal tract. Recent evidence also implicates this signaling pathway in the postembryonic regulation of stem-cell number in epithelia and blood. The family of HH proteins consists of at least three different members, i.e., sonic HH (SHH), Indian HH (IHH), and desert HH (DHH). SHH is the most broadly expressed member of this family and is probably responsible for the major effects of this signaling pathway. The HH signal is received and transduced via a specific receptor complex composed of patched (PTCH) and smoothened (SMOH) transmembrane proteins. Abnormalities in this signaling cascade have been found in various developmental pathologies and neoplasms such as basal cell carcinoma. The abnormalities are associated with congenital or sporadic genetic alteration affecting function of different components of the HH signaling pathway, including SHH, PTCH, SMOH and GLI proteins.

Influence of culture medium pH on cytotoxicity of CD95L in vitro.

CD95L belongs to the tumor necrosis factor-alpha (TNF-alpha) family, the members of which induce apoptosis by activation of their specific receptors. However, there are a few publications suggesting that two of these factors, TNF-alpha and TNF-beta, are able to reveal cytotoxic effect in pH-dependent manner. Therefore we investigated, whether CD95L may also reveal pH-dependent cytotoxicity. We analyzed influence of CD95L on U937 and K562 human cell lines at pH 5.1 and pH 7.4 using radioactive chromium release and tetrazolium salt (MTT) reduction assays. Expression of CD95 in both cell lines was estimated using RNase Protection Assay and FACS analysis. It has been found that short incubation of cells at pH 5.1 did not visibly affect their viability, as measured after 16 or 20 h. Incubation of U937 with CD95L at pH 7.4 resulted in a dose-dependent cell cytotoxicity. The effect was significantly augmented by incubation of cells with CD95L at pH 5.1. K562 cell line was resistant to CD95L at pH 7.4. This result correlated with the lack of CD95 expression in K562 cells. However, incubation at pH 5.1 resulted in a sensitization of K562 cells to CD95L. Our results suggest that CD95L, similarly to TNF-alpha, is able to reveal its cytotoxic activity in a receptor-independent manner and this activity strongly depends on pH of the environment.

Recipient uridine 5'-diphospho-glucuronosyltransferase UGT1A9 c.98T>C variant determines transplanted kidney filtration rate.

Mycophenolic acid preparations are commonly used in prophylaxis of kidney allograft acute rejection. The medication is metabolized by uridine diphosphate glucuronosyltransferases, mainly UGT1A9 present in liver, kidney, and intestine. The effect of UGT1A9 allelic variants on drug metabolism in healthy volunteers and transplant recipients has been previously evaluated; these studies included the UGT1A9 c.98T>C polymorphism (rs72551330, p.Met33Thr) causing methionine-to-threonine substitution in the polypeptide chain. The study objective was to evaluate the relationship between UGT1A9 c.98T>C polymorphism and kidney graft function and survival and the risk of acute allograft rejection. Kidney recipients who underwent transplantation between 2000 and 2007 at the Medical University of Warsaw were included. Clinical data originated from standard medical records, UGT1A9 c.98T>C was genotyped using a polymerase chain reaction-restriction fragment length polymorphism method. A group of 243 kidney transplant recipients was enrolled in the study. The frequency of the c.98C allele was 2.4% (12 of 486). Most of the carriers of the allelic variant (10 of 12) received cyclosporine A at transplantation. In the c.98C allele carriers, worse function of the renal allograft, manifested by a significantly lower glomerular filtration rate, was found in the first posttransplantation month and persisted at a lower level for 8 years after the procedure (for comparison of the UGT1A9 c.98 TT vs the UGT1A9 c.98 TC groups, P = .03). No association was found between the presence of the UGT1A9 c.98C allele and the risk of delayed renal graft function, acute rejection, dysfunction of the renal graft, or dialysis treatment reintroduction. Significantly lower estimated glomerular filtration rate of the renal allograft in UGT1A9 c.98C carriers did not translate into decreased allograft survival.

Uridine diphosphate glucuronosyltransferase 2B7 variant p.His268Tyr as a predictor of kidney allograft early acute rejection.

BACKGROUND: Uridine diphosphate glucuronosyltransferase (UGT2B7) is responsible for conversion of mycophenolic acid to mycophenolic acyl-glucuronide (acylMPAG). Conflicting data exist regarding the role of UGT2B7 p.His268Tyr (802C>T, rs7439366) variant in the clinical course following organ transplantation. STUDY AIM: The aim of this study was to reveal an association between UGT2B7 p.His268Tyr (802C>T, rs7439366) polymorphism and kidney transplantation outcome. STUDY DESIGN, PATIENTS, AND METHOD: Genomic DNA of 235 kidney transplant recipients was genotyped for UGT2B7 802C>T using TagMan single nucleotide polymorphism (SNP) genotyping assay. Maintenance immunosuppression used mycophenolate mofetil (MMF) and cyclosporine A (n = 137) or tacrolimus (n = 98). Primary end-point was biopsy-confirmed acute rejection within 3 and 12 post-transplantation months. Secondary end-points included gastrointestinal side effects, leukopenia, lymphopenia, neutropenia, and infections. Statistical analysis was performed with the aid of SAS System using kernel-smoothed estimates of acute graft rejection hazard function. The log-rank test and hazard ratio were used to reflect association between UGT2B7 802C>T variant and risk of acute graft rejection. RESULTS: Within 3 postimplantation months 38 (16.2%) patients experienced acute rejection; 33 were allele C carriers in UGT2B7 802C>T SNP and 5 were TT homozygotes (P < .0457). Allele C-associated risk of rejection was 2.50 and remained between 2.19 and 3.02 after adjustment for clinical confounders, ie, HLA mismatch, panel-reactive antibodies, donor age, repeated transplantation, induction therapy, donor type, delayed graft function, applied calcineurin inhibitor, or MMF dosing. We found no association between the polymorphism and gastrointestinal side effects, leukopenia, lymphopenia, neutropenia, and infections. CONCLUSION: UGT2B7 802C>T genotyping may help identify patients with excessive early acute rejection risk.

Lymphocyte counts in kidney allograft recipients are associated with IMPDH2 3757T>C gene polymorphism.

Inosine monophosphate dehydrogenase (IMPDH), the rate-limiting enzyme for de novo synthesis of guanine nucleotides, is required for lymphocyte proliferation. Inhibition of IMPDH by mycophenolic acid (MPA) constitutes part of an immunosuppressive therapy in kidney allograft recipients. The 3757T>C polymorphic variant (rs11706052) of the IMPDH2 gene, which encodes 1 of 2 IMPDH isoenzymes, has been associated with increased IMPDH activity and reduced ability of MPA to exert antiproliferative effects on lymphocytes. The association of IMPDH2 3757T>C SNP with posttransplant courses of kidney allograft recipients remains unclear. Therefore, the aim of the present study was to evaluate associations between this single nucleotide polymorphism and common posttransplant complications among Polish kidney allotransplant recipients. We observed that the frequency of IMPDH2 3757C allele in this group (n=177) did not differ significantly from a control cohort representing the background population of Poland (n=550). There were no significant differences between patients carrying the IMPDH2 3757CT and TT genotypes with respect to acute rejection risk, neutropenia, or incidences of serious infections or gastrointestinal side effects. However, we noted that the 3757C allele was associated with higher lymphocyte counts and a reduced incidence of lymphopenia among kidney allograft recipients. Our findings may be of practical significance to tailor immunosuppressive regimens in kidney transplant recipients.

Multidrug resistance-associated protein 2 gene (ABCC2) variant in kidney allograft recipients.

Multidrug resistance-associated proteins may play crucial roles in the protection of internal organs, particularly the kidneys and liver, from various toxic agents. Little is known about their significance in transplanted organ function and survival. The aim of the present study was to evaluate the frequency of functional ABCC2 4544A>G polymorphism in 165 renal transplant recipients. DNA was isolated from peripheral blood and ABCC2 4544A>G polymorphism was assessed by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Analysis of allele and genotype frequencies revealed that the presence of ABCC2 4544 A allele was associated with prolonged observation time and may have an impact on a greater frequency of proteinuria. This observation strongly suggested that particular alleles of the ABCC2 gene may contribute to transplantation outcomes.

[Signal transduction mechanisms induced by epidermal growth factor receptor (EGFR) and their role in apoptosis regulation]. / Mechanizmy przekazywania sygnalów przez receptor dla naskórkowego czynnika wzrostu (EGFR) oraz ich rola w regulacji apoptozy.

Stimulation of epidermal growth factor receptor (EGFR) leads to cell proliferation and plays an important role in cancerogenesis. It seems that these effects are a consequence of triggering of various signal transduction pathways involving PI-3K and MAP kinase activation. Surprisingly, under certain circumstances stimulation of EGFR may also result in cell growth arrest and apoptosis induction. It is possible that anti-proliferative effect of EGF depends on STAT protein activation. It has been reported, that STAT upregulates expression of cyclin-dependent kinase inhibitor, which blocks the cell cycle. Additionally, STAT may increase caspase 1 (ICE) expression, which seems to be necessary for apoptosis induced by EGF. Intracellular mechanisms involved in EGFR proapoptotic activity still remains poorly understood and, because of their potential clinical significance, require further investigation.

[Induction of apoptosis by receptors for factors from the TNF family]. / Indukcja apoptozy przez receptory dla czynników z rodziny TNF.

Mechanisms leading to induction of apoptosis by TNF family receptors involve intracellular activation of cysteinyl-aspartate-specific proteases (caspases). Caspase activation requires engagement of adaptor proteins. It is plausible, that caspase activation is sufficient for cell death in course of receptor-dependent induction of apoptosis. However, there are some data that programmed cell death involves also generation of ceramides, arachidonic acid metabolism, or MAP kinase (SAPK/JNK) activation. On the other hand, TNF receptor family triggers some protective, anti-apoptotic mechanisms, i.e. protein kinase C (PKC) and NF-kappa B. The outcome of induction of apoptosis by TNF receptor family depends on the cell type, its physiological condition and influence of environmental factors.