155 research outputs found

    Gemcitabine in combination with EGF-Receptor antibody (Cetuximab) as a treatment of cholangiocarcinoma: a case report

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    BACKGROUND: Extensive disease of cholangiocarcinoma (CC) determines the overall outcome and limits curative resection. Despite chemotherapy, which has been introduced to improve the outcome of biliary tract malignancies, the benefit in survival is still marginal. CASE PRESENTATION: We report a 69-year-old patient with non-resectable CC showing hepatic metastasis and peritoneal carcinomatosis. Diagnosis was based on computed tomography, mini-laparoscopy and bioptic specimens. Histology revealed an adenocarcinoma of the biliary tract with expression of epithelial growth factor receptor. After informed consent the patient received experimental gemcitabine (1000 mg/m(2)) every other week and cetuximab (250 mg/m(2)) weekly for palliative chemotherapy. During the reported follow up (since time of first presentation) 20 cycles of chemotherapy were administered. Relevant chemotherapy-related toxicity was limited on gemcitabine-associated side effects. Predominantly, haematological toxicity (CTC, grade 3) and neutropenic fever (CTC, grade 3) promoted by catheter-related sepsis were observed. Cetuximab caused only mild skin toxicity (CTC, grade 1). Chemotherapy led to a partial response (> 30% reduction, according to RECIST) of the target lesions and disappearance of the peritoneal carcinomatosis as shown by computed tomography. Partial response occurred after 17 weeks of treatment and remained stable during the entire course of chemotherapy for 9.7 months. In parallel, Ca 19-9 serum levels, which were elevated 5-fold at time of diagnosis, returned to normal after 16 weeks of treatment. The performance status stabilized and intravenous alimentation could be discontinued. CONCLUSION: Our experience from one patient with CC suggests, that a combination of cytotoxic chemotherapy together with cetuximab may show promising efficacy in respect to survival and quality of life. Therefore cetuximab, as a component of palliative chemotherapy in biliary tract cancer, needs further evaluation in prospective randomized trials

    Early virological response may predict treatment response in sofosbuvir-based combination therapy of chronic hepatitis c in a multi-center “real-life” cohort

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    Background: The combination of sofosbuvir (SOF), ribavirin (RBV) and peg-interferon-alfa-2a (peg-IFN-alfa-2a) as well as the combination of SOF and RBV for the treatment of patients infected with hepatitis c virus (HCV) has improved rates of sustained virological response (SVR) considerably in recent trials. However, there is only limited data concerning the efficacy and safety in a “real-life” cohort. Methods: We analyzed a cohort of 119 patients with chronic HCV infection treated at four investigational sites in Germany. All patients received either a combination treatment of SOF, RBV and peg-IFN-alfa-2a or SOF and RBV. Results: The rates of SVR at 12 weeks after end of treatment (SVR 12) were as follows: Among 76 patients with genotype 1 infection the SVR 12 rate was 74 % (n = 56), among 14 patients with genotype 2 infection the SVR 12 rate was 79 % (n = 11), among 24 patients with genotype 3 infection the SVR 12 rate was 92 % (n = 22) and among 5 patients with genotype 4 infection the SVR 12 rate was 80 % (n = 4). Of all 26 patients with a relapse in our cohort, 69 % (n = 18) of these patients presented with liver cirrhosis and 58 % (n = 15) were treatment experienced. Notably, the level of HCV-RNA after 4 weeks of treatment was a significant predictor of treatment response in genotype 1 patients. Patients with HCV-RNA levels ≥ 12 IU ml-1 after 4 weeks of treatment achieved SVR 12 only in 30 % (n = 17/56, p < 0.0001) of cases and treatment response was even lower with SVR 12 of 25 % (n = 5/20, p = 0.0016) in the subgroup of patients with cirrhosis. Conclusion: We observed a high rate of SVR 12 with SOF-based treatment regimes, however probably due to the high number of patients with liver cirrhosis and prior treatment experience, treatment response rates were lower than in previously published trials. In genotype 1 patients the analysis of early virological response may predict treatment response in SOF-based combination therapies

    A comparative analysis of two conserved motifs in bacterial poly(A) polymerase and CCA-adding enzyme

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    Showing a high sequence similarity, the evolutionary closely related bacterial poly(A) polymerases (PAP) and CCA-adding enzymes catalyze quite different reactions—PAP adds poly(A) tails to RNA 3′-ends, while CCA-adding enzymes synthesize the sequence CCA at the 3′-terminus of tRNAs. Here, two highly conserved structural elements of the corresponding Escherichia coli enzymes were characterized. The first element is a set of amino acids that was identified in CCA-adding enzymes as a template region determining the enzymes' specificity for CTP and ATP. The same element is also present in PAP, where it confers ATP specificity. The second investigated region corresponds to a flexible loop in CCA-adding enzymes and is involved in the incorporation of the terminal A-residue. Although, PAP seems to carry a similar flexible region, the functional relevance of this element in PAP is not known. The presented results show that the template region has an essential function in both enzymes, while the second element is surprisingly dispensable in PAP. The data support the idea that the bacterial PAP descends from CCA-adding enzymes and still carries some of the structural elements required for CCA-addition as an evolutionary relic and is now fixed in a conformation specific for A-addition

    The asparagine-transamidosome from Helicobacter pylori: a dual-kinetic mode in non-discriminating aspartyl-tRNA synthetase safeguards the genetic code

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    Helicobacter pylori catalyzes Asn-tRNAAsn formation by use of the indirect pathway that involves charging of Asp onto tRNAAsn by a non-discriminating aspartyl-tRNA synthetase (ND-AspRS), followed by conversion of the mischarged Asp into Asn by the GatCAB amidotransferase. We show that the partners of asparaginylation assemble into a dynamic Asn-transamidosome, which uses a different strategy than the Gln-transamidosome to prevent the release of the mischarged aminoacyl-tRNA intermediate. The complex is described by gel-filtration, dynamic light scattering and kinetic measurements. Two strategies for asparaginylation are shown: (i) tRNAAsn binds GatCAB first, allowing aminoacylation and immediate transamidation once ND-AspRS joins the complex; (ii) tRNAAsn is bound by ND-AspRS which releases the Asp-tRNAAsn product much slower than the cognate Asp-tRNAAsp; this kinetic peculiarity allows GatCAB to bind and transamidate Asp-tRNAAsn before its release by the ND-AspRS. These results are discussed in the context of the interrelation between the Asn and Gln-transamidosomes which use the same GatCAB in H. pylori, and shed light on a kinetic mechanism that ensures faithful codon reassignment for Asn

    Suitable Electrode Choice for Robotic-Assisted Cochlear Implant Surgery: A Systematic Literature Review of Manual Electrode Insertion Adverse Events

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    BACKGROUND AND OBJECTIVE: The cochlear implant (CI) electrode insertion process is a key step in CI surgery. One of the aims of advances in robotic-assisted CI surgery (RACIS) is to realize better cochlear structure preservation and to precisely control insertion. The aim of this literature review is to gain insight into electrode selection for RACIS by acquiring a thorough knowledge of electrode insertion and related complications from classic CI surgery involving a manual electrode insertion process. METHODS: A systematic electronic search of the literature was carried out using PubMed, Scopus, Cochrane, and Web of Science to find relevant literature on electrode tip fold over (ETFO), electrode scalar deviation (ESD), and electrode migration (EM) from both pre-shaped and straight electrode types. RESULTS: A total of 82 studies that include 8,603 ears implanted with a CI, i.e., pre-shaped (4,869) and straight electrodes (3,734), were evaluated. The rate of ETFO (25 studies, 2,335 ears), ESD (39 studies, 3,073 ears), and EM (18 studies, 3,195 ears) was determined. An incidence rate (±95% CI) of 5.38% (4.4–6.6%) of ETFO, 28.6% (26.6–30.6%) of ESD, and 0.53% (0.2–1.1%) of EM is associated with pre-shaped electrodes, whereas with straight electrodes it was 0.51% (0.1–1.3%), 11% (9.2–13.0%), and 3.2% (2.5–3.95%), respectively. The differences between the pre-shaped and straight electrode types are highly significant (p < 0.001). Laboratory experiments show evidence that robotic insertions of electrodes are less traumatic than manual insertions. The influence of round window (RW) vs. cochleostomy (Coch) was not assessed. CONCLUSION: Considering the current electrode designs available and the reported incidence of insertion complications, the use of straight electrodes in RACIS and conventional CI surgery (and manual insertion) appears to be less traumatic to intracochlear structures compared with pre-shaped electrodes. However, EM of straight electrodes should be anticipated. RACIS has the potential to reduce these complications

    Respiratory Infections by HMPV and RSV Are Clinically Indistinguishable but Induce Different Host Response in Aged Individuals

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    Background: Human metapneumovirus and respiratory syncytial virus can cause severe respiratory diseases, especially in infants, young children, and the elderly. So far it remains unclear why infections in the elderly become life threatening despite the presence of neutralizing antibodies in the serum, and to which extent double infections worsen the clinical course. Methods: Young and aged BALB/c-mice were infected with RSV or/and HMPV. Appearance of the mice was observed during course of infection. On day 5 p.i. animals were dispatched by cervical dislocation and levels of TNF-a and NF-kB were determined. Results: The observation of activity, weight and appearance of the different mice showed no differences among the tested groups. Despite this, the immunologic response depends on the animals ’ age and the virus they were infected with. In young animals, NF-kB levels were elevated if infected with HMPV and HMPV/RSV but remained low in RSV infections, whereas in aged animals the opposite was observed: solely RSV-infected animals showed elevated levels of NF-kB. TNF-a was slightly elevated in HMPV-infected young and old animals, but only in young animals this elevation was significant. Conclusions: Contrary to other studies, no weight loss or change in activity despite productive lung infection with the different viruses were observed. This may be due to the weaker anaesthesia or the lesser volume of virus solution used

    Minimal Reporting Standards for Active Middle Ear Hearing Implants.

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    There is currently no standardized method for reporting audiological, surgical and subjective outcome measures in clinical trials with active middle ear implants (AMEIs). It is often difficult to compare studies due to data incompatibility and to perform meta-analyses across different centres is almost impossible. A committee of ENT and audiological experts from Germany, Austria and Switzerland decided to address this issue by developing new minimal standards for reporting the outcomes of AMEI clinical trials. The consensus presented here aims to provide a recommendation to enable better inter-study comparability

    Electrically evoked compound action potentials are different depending on the site of cochlear stimulation.

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    One of the many parameters that can affect cochlear implant (CI) users' performance is the site of presentation of electrical stimulation, from the CI, to the auditory nerve. Evoked compound action potential (ECAP) measurements are commonly used to verify nerve function by stimulating one electrode contact in the cochlea and recording the resulting action potentials on the other contacts of the electrode array. The present study aimed to determine if the ECAP amplitude differs between the apical, middle, and basal region of the cochlea, if double peak potentials were more likely in the apex than the basal region of the cochlea, and if there were differences in the ECAP threshold and recovery function across the cochlea. ECAP measurements were performed in the apical, middle, and basal region of the cochlea at fixed sites of stimulation with varying recording electrodes. One hundred and forty one adult subjects with severe to profound sensorineural hearing loss fitted with a Standard or FLEX(SOFT) electrode were included in this study. ECAP responses were captured using MAESTRO System Software (MED-EL). The ECAP amplitude, threshold, and slope were determined using amplitude growth sequences. The 50% recovery rate was assessed using independent single sequences that have two stimulation pulses (a masker and a probe pulse) separated by a variable inter-pulse interval. For all recordings, ECAP peaks were annotated semi-automatically. ECAP amplitudes were greater upon stimulation of the apical region compared to the basal region of the cochlea. ECAP slopes were steeper in the apical region compared to the basal region of the cochlea and ECAP thresholds were lower in the middle region compared to the basal region of the cochlea. The incidence of double peaks was greater upon stimulation of the apical region compared to the basal region of the cochlea. This data indicates that the site and intensity of cochlear stimulation affect ECAP properties

    Electrically evoked compound action potentials are different depending on the site of cochlear stimulation

    Get PDF
    One of the many parameters that can affect cochlear implant (CI) users' performance is the site of presentation of electrical stimulation, from the CI, to the auditory nerve. Evoked compound action potential (ECAP) measurements are commonly used to verify nerve function by stimulating one electrode contact in the cochlea and recording the resulting action potentials on the other contacts of the electrode array. The present study aimed to determine if the ECAP amplitude differs between the apical, middle, and basal region of the cochlea, if double peak potentials were more likely in the apex than the basal region of the cochlea, and if there were differences in the ECAP threshold and recovery function across the cochlea. ECAP measurements were performed in the apical, middle, and basal region of the cochlea at fixed sites of stimulation with varying recording electrodes. One hundred and forty one adult subjects with severe to profound sensorineural hearing loss fitted with a Standard or FLEX(SOFT) electrode were included in this study. ECAP responses were captured using MAESTRO System Software (MED-EL). The ECAP amplitude, threshold, and slope were determined using amplitude growth sequences. The 50% recovery rate was assessed using independent single sequences that have two stimulation pulses (a masker and a probe pulse) separated by a variable inter-pulse interval. For all recordings, ECAP peaks were annotated semi-automatically. ECAP amplitudes were greater upon stimulation of the apical region compared to the basal region of the cochlea. ECAP slopes were steeper in the apical region compared to the basal region of the cochlea and ECAP thresholds were lower in the middle region compared to the basal region of the cochlea. The incidence of double peaks was greater upon stimulation of the apical region compared to the basal region of the cochlea. This data indicates that the site and intensity of cochlear stimulation affect ECAP properties
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