Publications by authors named "Perrakis A"

We experimentally demonstrate that the coacervation of a biopolymer can trigger a hydrodynamic instability when a coacervate is formed upon injection of a xanthan gum dispersion into a cationic surfactant (CTAB) solution. The local increase of the viscosity due to the coacervate formation induces a viscous fingering instability. Three characteristic displacement regimes were observed: a viscous fingering dominated regime, a buoyancy-controlled "volcano" regime and a "fan"-like regime determined by the coacervate membrane dynamics.

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Base-J (β-D-glucopyranosyloxymethyluracil) is an unusual kinetoplastid-specific DNA modification, recognized by base-J containing DNA (J-DNA) binding proteins JBP1 and JBP3. Recognition of J-DNA by both JBP1 and JBP3 takes place by a conserved J-DNA binding domain (JDBD). Here we show that JDBD-JBP3 has about 1,000-fold weaker affinity to base-J than JDBD-JBP1 and discriminates between J-DNA and unmodified DNA with a factor ∼5, whereas JDBD-JBP1 discriminates with a factor ∼10,000.

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Article Synopsis
  • A retrospective study assessed the diagnostic effectiveness of C-reactive protein (CRP) and leucocyte count in differentiating complicated (CAA) from uncomplicated acute appendicitis (UAA) based on EAES guidelines, involving 285 patients in Germany from 2019 to 2021.
  • The study found that CRP levels were significantly higher in CAA patients compared to UAA patients, showing medium diagnostic value for identifying CAA and a cutoff at 44.3 mg/L, while leucocyte count had a low predictive value.
  • Higher CRP levels were linked to an increased risk of postoperative complications and longer hospital stays, indicating that CRP is a useful marker for diagnosing CAA within the EA
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The "Robotic Curriculum for young Surgeons" (RoCS) was launched 03/2020 to address the increasing importance of robotics in surgical training. It aims to provide residents with foundational robotic skills by involving them early in their training. This study evaluated the impact of RoCS' integration into clinical routine on patient outcomes.

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: In patients diagnosed with uncomplicated acute appendicitis (UAA), the absence of calcified deposits or stones, called appendicoliths, often leads to consideration of non-operative treatment (NOT), despite the notable treatment failure rate associated with this approach. Previous research has indirectly estimated the prevalence of appendicoliths to range between 15% and 38% retrospectively by CT scan, intraoperative palpation, and pathology report, thereby potentially missing certain concrements. Our hypothesis proposes that this reported prevalence significantly underestimates the occurrence of appendicoliths, which could explain the high failure rate of 29% of patients with appendicitis observed with NOT.

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Uncover the pivotal link between lymphocyte-specific protein tyrosine kinase (Lck)-related genes and clinical risk stratification in pancreatic cancer. This study identifies shared genes between differentially expressed genes (DEGs) and Lck-related genes in pancreatic cancer using a methodological framework rooted in The Cancer Genome Atlas database. Feature gene selection is accomplished and a signature model is constructed.

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Microtubules are a major component of the cytoskeleton and can accumulate a plethora of modifications. The microtubule detyrosination cycle is one of these modifications; it involves the enzymatic removal of the C-terminal tyrosine of α-tubulin on assembled microtubules and the re-ligation of tyrosine on detyrosinated tubulin dimers. This modification cycle has been implicated in cardiac disease, neuronal development, and mitotic defects.

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Introduction: The certification of oncological units as colorectal cancer centers (CrCCs) has been proposed to standardize oncological treatment and improve the outcomes for patients with colorectal cancer (CRC). The proportion of patients with CRC in Germany that are treated by a certified center is around 53%. Lately, the effect of certification on the treatment outcomes has been critically discussed.

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: Secondary malignant tumors of the pancreas are rare, representing 2-5% of all pancreatic malignancies. Nevertheless, the pancreas is one of the target organs in cases of metastatic clear cell renal cell carcinoma (CCRCC). Additionally, recurrent metastasis may occur.

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Article Synopsis
  • Talin connects the actomyosin cytoskeleton to integrins, allowing tension to be transmitted to the extracellular matrix and modulating mechanosignaling through additional protein interactions.
  • The study identifies Caskin2 as a novel protein that directly interacts with talin, specifically through its C-terminal LD motif, and associates with the WAVE regulatory complex to aid in cell migration.
  • Caskin2's interaction with Abi1 is influenced by phosphorylation, and in certain cancer cells, it localizes to areas associated with plasma membranes and focal adhesions, suggesting a link between integrin adhesion and microtubule dynamics.
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Evolution leads to conservation of amino acid residues in protein families. Conserved proline residues are usually considered to ensure the correct folding and to stabilize the three-dimensional structure. Surprisingly, proline residues that are highly conserved in class A β-lactamases were found to tolerate various substitutions without large losses in enzyme activity.

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Background: ALPPS leads to fast and effective liver hypertrophy. This enables the resection of extended tumors. Conventional ALPPS is associated with high morbidity and mortality.

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The main protease M, nsp5, of SARS-CoV-2 (SCoV2) is one of its most attractive drug targets. Here, we report primary screening data using nuclear magnetic resonance spectroscopy (NMR) of four different libraries and detailed follow-up synthesis on the promising uracil-containing fragment Z604 derived from these libraries. Z604 shows time-dependent binding.

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Transient receptor potential (TRP) channels are strongly associated with colon cancer development and progression. This study leveraged a multivariate Cox regression model on publicly available datasets to construct a TRP channels-associated gene signature, with further validation of signature in real world samples from our hospital treated patient samples. Kaplan-Meier (K-M) survival analysis and receiver operating characteristic (ROC) curves were employed to evaluate this gene signature's predictive accuracy and robustness in both training and testing cohorts, respectively.

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Objectives: The unexpected global overload of the health system during COVID-19 pandemic has caused changes in management of acute appendicitis worldwide. Whereas conservative treatment was widely recommended, the appendicectomy remained standard therapy in Germany. We aimed to investigate the impact of COVID-19 pandemic on treatment routine for acute appendicitis at University Hospital of Magdeburg.

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Objectives: Rectal prolapse is defined as prolapse of all layers of rectal wallout of the anal sphincter. The aim was to (i) describe the extremely rare combination of a rectal prolapse with colon cancer in an older female patient, (ii) comment on management-specific aspects and (iii) derive some generalizing recommendations by means of a scientific case report and based on the case-specific experiences related to the clinical management and current references from the medical literature.

Case Presentation: A 69-year old female patient with cancer of the sigmoid colon at a manifest rectal prolapse was diagnosed.

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Introduction: Pancreatic cancer is a highly aggressive cancer, and early diagnosis significantly improves patient prognosis due to the early implementation of curative-intent surgery. Our study aimed to implement machine-learning algorithms to aid in early pancreatic cancer diagnosis based on minimally invasive liquid biopsies.

Materials And Methods: The analysis data were derived from nine public pancreatic cancer miRNA datasets and two sequencing datasets from 26 pancreatic cancer patients treated in our medical center, featuring small RNAseq data for patient-matched tumor and non-tumor samples and serum.

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Current treatment for glioblastoma includes tumor resection followed by radiation, chemotherapy, and periodic post-operative examinations. Despite combination therapies, patients face a poor prognosis and eventual recurrence, which often occurs at the resection site. With standard MRI imaging surveillance, histologic changes may be overlooked or misinterpreted, leading to erroneous conclusions about the course of adjuvant therapy and subsequent interventions.

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Base-J (β-D-glucopyranosyloxymethyluracil) is a modified DNA nucleotide that replaces 1% of thymine in kinetoplastid flagellates. The biosynthesis and maintenance of base-J depends on the base-J-binding protein 1 (JBP1) that has a thymidine hydroxylase domain and a J-DNA-binding domain (JDBD). How the thymidine hydroxylase domain synergizes with the JDBD to hydroxylate thymine in specific genomic sites, maintaining base-J during semi-conservative DNA replication, remains unclear.

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The Collaborative Computational Project No. 4 (CCP4) is a UK-led international collective with a mission to develop, test, distribute and promote software for macromolecular crystallography. The CCP4 suite is a multiplatform collection of programs brought together by familiar execution routines, a set of common libraries and graphical interfaces.

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Background: The challenges of an adequate, efficient and rational medical treatment and care of patients are always associated with an interprofessional activity of several specialist disciplines.

Aim: The spectrum of variable diagnoses and the profile of surgical decision-making with further surgical measures within the framework of senior physician consultation in general and visceral surgery for neighboring medical disciplines were analyzed on a representative patient cohort over a defined observational time period.

Patients And Methods: All consecutive patients (n = 549 cases) were documented as part of a clinical systematic prospective single center observational study at a tertiary center using a computer-based patient registry over 10 years (1 October 2006-30 September 2016).

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Microtubules are an important part of the cytoskeleton and are involved in intracellular organization, cell division, and migration. Depending on the posttranslational modifications, microtubules can form complexes with various interacting proteins. These microtubule-protein complexes are often implicated in human diseases.

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Autotaxin (ATX; ENPP2) produces the lipid mediator lysophosphatidic acid (LPA) that signals through disparate EDG (LPA) and P2Y (LPA) G protein-coupled receptors. ATX/LPA promotes several (patho)physiological processes, including in pulmonary fibrosis, thus serving as an attractive drug target. However, it remains unclear if clinical outcome depends on how different types of ATX inhibitors modulate the ATX/LPA signaling axis.

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Rationale And Objectives: Sarcopenia is defined as skeletal muscle loss and can be assessed by cross-sectional imaging. Our aim was to establish the effect of sarcopenia on relevant outcomes in patients with pancreatic ductal adenocarcinoma (PDAC) in curative and palliative settings based on a large patient sample.

Materials And Methods: MEDLINE library, EMBASE and SCOPUS databases were screened for the associations between sarcopenia and mortality in patients with PDAC up to March 2022.

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