Mimicking Nonribosomal Peptides from the Marine Actinomycete Streptomyces sp. H-KF8 Leads to Antimicrobial Peptides

Microorganisms within the marine environment have been shown to be very effective sources of naturally produced antimicrobial peptides (AMPs). Several nonribosomal peptides were identified based on genome mining predictions of Streptomyces sp. H-KF8, a marine Actinomycetota isolated from a remote Northern Chilean Patagonian fjord. Based on these predictions, a series of eight peptides, including cyclic peptides, were designed and chemically synthesized. Six of these peptides showed antimicrobial activity. Mode of action studies suggest that two of these peptides potentially act on the cell membrane via a novel mechanism allowing the passage of small ions, resulting in the dissipation of the membrane potential. This study shows that though structurally similar peptides, determined by NMR spectroscopy, the incorporation of small sequence mutations results in a dramatic influence on their bioactivity including mode of action. The qualified hit sequence can serve as a basis for more potent AMPs in future studies.

Minimally invasive accessory splenectomy for recurrent gastric variceal bleeding due to left-sided portal hypertension: report of the first case

Upper gastrointestinal bleeding from esophagogastric varices is a common scenario, especially in patients with portal hypertension induced by liver cirrhosis or other diseases with thrombosis of the splenic vein. However, accessory spleen as pathophysiological cause of a regional, left-sided portal hypertension and consecutive development of isolated gastric varices is rare. We report a case of recurrent gastric variceal bleeding resulting from sinistral portal hypertension associated with an accessory spleen in a patient who had traumatic splenectomy many decades before. The accessory spleen is an extremely rare cause for the development of regional, left-sided portal hypertension leading to isolated gastric varices. Minimally invasive splenectomy is a safe and efficient treatment option.

Contrast enhanced ultrasound (CEUS) with parametric imaging and time intensity curve analysis (TIC) for evaluation of the success of prostate arterial embolization (PAE) in cases of prostate hyperplasia

AIM

To evaluate the use of dynamic contrast enhanced ultrasound (CEUS) with parametric color-coded imaging and time intensity curve analysis (TIC) for planning and follow-up after prostate arterial embolization (PAE).

MATERIAL/METHOD

Before and after selective iliacal embolization by PAE with a follow up of 6 months 18 male patients (43-78 years, mean 63±3.5 years) with histopathological proven benign prostate hyperplasia were examined by one experienced examiner. A multifrequency high resolution probe (1-6 MHz) was used for transabdominal ultrasound and CEUS with bolus injections of 2.4 ml sulphur-hexafluoride microbubbles. Independent evaluation of color-coded parametric imaging before and after PAE by in PACS stored DICOM loops from arterial phase (10-15 s) up to 1min were performed. Criteria for successful treatment were reduction of early arterial enhancement by changes of time to peak (TTP) and area under the curve (AUC) by measurements in 8 regions of interest (ROI) of 5 mm in diameter at the margin and in the center and changes from hyperenhancement in parametric imaging (perfusion evaluation of arterial enhancement over 15 s) from red and yellow to blue and green by partial infarctions. Reference imaging method was the contrast high resolution 3 tesla magnetic resonance tomography (MRI) using 3D vibe sequences before and after PAE and for the follow up after 3 and 6 months.

RESULTS

PAE was technically and clinically successful in all 18 patients with less clinical symptoms and reduction of the gland volume. In all cases color-coded CEUS parametric imaging was able to evaluate partial infarction after embolization with changes from red and yellow to green and blue colors in the embolization areas. Relevant changes could be evaluated for TIC-analysis of CEUS with reduced arterial enhancement in the arterial phase and prolonged enhancement of up to 1 min with significant changes (p = 0.0024). The area under the curve (AUC) decreased from 676±255.04 rU (160 rU-1049 rU) before PAE to 370.43±255.19 rU (45 rU-858 rU) after PAE. Time to peak (TTP) did not change significantly (p = 0.6877); TTP before PAE was 25.82±9.04 s (12.3 s-42.5 s) and after PAE 24.43±9.10 s (12-39 s). Prostate volume decreased significantly (p = 0.0045) from 86.93±34.98 ml (30-139 ml) before PAE to 50.57±26.26 ml (19-117 ml) after PAE. There were no major complications and, in most cases (14/18) a volume reduction of the benign prostate hyperplasia occurred.

CONCLUSION

Performed by an experienced examiner CEUS with parametric imaging and TIC-analysis is highly useful to further establish prostatic artery embolization (PAE) as a successful minimal invasive treatment of benign prostatic hyperplasia.

Interdisziplinäre Tumorkonferenzen in der radiologischen Routine

Ziel

Interdisziplinäre Tumorkonferenzen (Boards) sind regelmäßig stattfindende Konferenzen, bei denen unter medizinischen Experten verschiedener Fachrichtungen versucht wird, einen für den Patienten optimierten Behandlungsplan zu erstellen. Die Anwesenheit eines radiologischen Facharztes ist in nahezu allen relevanten Boards medizinisch unumgänglich. Um die aktuelle Beanspruchung der Radiologie durch derartige Boards systematisch zu evaluieren und auch um aktuelle Zahlen zur möglichen zukünftigen Personalplanung zu liefern, haben wir eine aktuelle Standortbestimmung in der Radiologie in Deutschland durchgeführt.

Material und Methoden

Es erfolgte eine Online-Umfrage. Zur Teilnahme aufgefordert waren alle 33 Lehrstuhlinhaber in der Radiologie sowie nach dem Zufallsprinzip weitere 50 ausgewählte Chefärzte für Radiologie an Krankenhäusern der Schwerpunkt-, oder Maximalversorgung (im Folgenden „Schwerpunktkliniken“ genannt).

Ergebnisse

Es nahmen 26 von 33 radiologischen Instituten (79 %) der Universitätskliniken und 28 von 50 Instituten (56 %) der Schwerpunktkliniken teil. Die Gesamtzahl der durchgeführten Tumorboards beträgt im Durchschnitt 3,3 pro Tag bzw. 16,7 pro Woche an Universitätskliniken und 2,6 pro Tag bzw. 13 pro Woche an Schwerpunktkliniken. Es ergibt sich ein durchschnittlicher zeitlicher Aufwand unter Berücksichtigung der Vorbereitungs- und Durchführungszeit sowie der Durchführungshäufigkeiten von 33,1 h/Woche an Universitätskliniken und 18,2 h/Woche an Schwerpunktkliniken. Dies entspricht bei einer 42-Stunden-Woche an Universitätskliniken 78,8 % und bei einer 40-Stunden-Woche an Schwerpunktkliniken 45,5 % einer Facharztstelle, die für interdisziplinäre Tumorboards notwendig sind.

Schlussfolgerung

Die „sprechende“ Radiologie mit ihren interdisziplinären Tumorboards stellt ein klinisches Selbstverständnis unter aktiver Teilnahme und Moderation durch die Radiologie dar, welches die Patientenversorgung evidenzbasiert verbessert. Dennoch muss bei der in der Medizin vorherrschenden Ressourcenknappheit für künftige Diskussionen bezüglich einer personellen Kompensation die hier erhobene Datengrundlage bzgl. des Personalaufwands der klinischen Radiologie für die Teilnahme an Tumorboards bedacht werden.

Thirty-day mortality after emergency surgery for obstructing colon cancer: survey and dedicated score from the French Surgical Association

AIM

The aim was to define risk factors for postoperative mortality in patients undergoing emergency surgery for obstructing colon cancer (OCC) and to propose a dedicated score.

METHOD

From 2000 to 2015, 2325 patients were treated for OCC in French surgical centres by members of the French National Surgical Association. A multivariate analysis was performed for variables with P value ≤ 0.20 in the univariate analysis for 30-day mortality. Predictive performance was assessed by the area under the receiver operating characteristic curve.

RESULTS

A total of 1983 patients were included. Thirty-day postoperative mortality was 7%. Multivariate analysis found five significant independent risk factors: age ≥ 75 (P = 0.013), American Society of Anesthesiologists (ASA) score ≥ III (P = 0.027), pulmonary comorbidity (P = 0.0002), right-sided cancer (P = 0.047) and haemodynamic failure (P < 0.0001). The odds ratio for risk of postoperative death was 3.42 with one factor, 5.80 with two factors, 15.73 with three factors, 29.23 with four factors and 77.25 with five factors. The discriminating capacity in predicting 30-day postoperative mortality was 0.80.

CONCLUSION

Thirty-day postoperative mortality after emergency surgery for OCC is correlated with age, ASA score, pulmonary comorbidity, site of tumour and haemodynamic failure, with a specific score ranging from 0 to 5.

Percutaneous Irreversible Electroporation: Long-term survival analysis of 71 patients with inoperable malignant hepatic tumors

Aim of this retrospective analysis was to evaluate the survival times after percutaneous irreversible electroporation (IRE) in inoperable liver tumors not amenable to thermal ablation. 71 patients (14 females, 57 males, median age 63.5 ± 10.8 years) with 103 liver tumors were treated in 83 interventions using IRE (NanoKnife® system). The median tumor short-axis diameter was 1.9 cm (minimum 0.4 cm, maximum 4.5 cm). 35 patients had primary liver tumors and 36 patients had liver metastases. The Kaplan-Meier method was employed to calculate the survival rates, and the different groups were compared using multivariate log-rank and Wilcoxon tests. The overall median survival time was 26.3 months; the median survival of patients with primary land secondary liver cancer did not significantly differ (26.8 vs. 19.9 months; p = 0.41). Patients with a tumor diameter >3 cm (p < 0.001) or more than 2 lesions (p < 0.005) died significantly earlier than patients with smaller or fewer tumors. Patients with hepatocellular carcinoma and Child-Pugh class B or C cirrhosis died significantly earlier than patients with Child-Pugh class A (p < 0.05). Patients with very early stage HCC survived significantly longer than patients with early stage HCC with a median survival of 22.3 vs. 13.7 months (p < 0.05).

Percutaneous irreversible electroporation (IRE) of prostate cancer: Contrast-enhanced ultrasound (CEUS) findings

PURPOSE

To evaluate the use of contrast-enhanced ultrasound (CEUS) after irreversible electroporation (IRE) of prostatic cancer tissue to assess the ablation status by depicting microvascularisation in the ablation area.

MATERIALS AND METHODS

Retrospective evaluation of CEUS of 13 patients (mean age: 61.4 ± 7.5 years) with histologically confirmed prostatic cancer who underwent percutaneous IRE. In the course of clinical routine, the tumor lesions were documented before, immediately after, and 1 day after the ablationusing color-coded transabdominal and transrectal CEUS. The obtained image data (DICOM loops and images) were subsequently evaluated by 2 experienced radiologists and assessed with regard to micro vascularisation by means of a 5-point scale.

RESULTS

CEUS images showed significantly reduced microcirculation of the lesions (mean 0.9 ± 0.6 cm (0.5-1.5 cm) after IRE. Microcirculation was reduced from 2.15 ± 0.56 prior to ablation to 0.65 ± 0.63 (p <  0.001) immediately after the ablation and to 0.27 ± 0.44 one day after IRE (p <  0.001).

CONCLUSION

This study showed rapid and significant reduction of the microcirculation in the ablation area afterpercutaneous IRE of prostatic cancer tissue.

[Management of solid pulmonary nodules]

The increasing availability of computed tomography has meant that the number of incidentally detected solitary pulmonary nodules (SPN) has greatly increased in recent years. A reasonable management of these SPN is necessary in order to firstly be able to detect malignant lesions early on and secondly to avoid upsetting the patient unnecessarily or carrying out further stressful diagnostic procedures. This review article shows how the dignity of SPNs can be estimated and based on this how the management can be accomplished taking established guidelines into consideration.

Vierzähnige Benzamidin-Liganden in ein-und mehrkemigen Kupfer(II)-Komplexen / Quadridentate Benzamidine Ligands in Mono-and Oligonuclear Copper(II) Complexes

Bridged N-thiocarbamoyl substituted bis-benzamidines (C2H5)2N-C(S)-N=C(Ph)-NH-R-NH-C(Ph)=N-C(S)-N(C2H5)2 with different moieties R (H2L1 : R = diphenylmethane-2,2'-diyl, H2 L2: R = diphenylmethane-3,3'-diyl, and H2L3: R = diphenylmethane-4,4'-diyl) were synthe­sized by the reaction of N-(thiocarbamoyl)benzimidoyl chlorides with diamines. These quadri­ dentate ligands form neutral mononuclear (CuL1), dinuclear (Cu2L3 2) and trinuclear (Cu3L2 3) copper(II) chelates in dependence of the different bridging unit in the ligands. The compounds were characterized by NMR, IR, EPR and XPS spectroscopy and FAB mass spectrometry. The molecular structures of the ligand H2L3 and the complex CuL1 have been determined by X-ray methods.

Labilisierung einer Carboxylgruppe der koordinierten Triethylentetramin- N, N, N′,N″, N‴, N‴ -hexaessigsäure (H6ttha): Koordinationszahlen 10 für [La(H ttha)]2- und 9 für [Dy(Httha)]2- in ihren Guanidiniumsalzen / Labilizing of a Carboxyl Group o f the Coordinated Triethylenetetramine-N, N, N′ ,N″, N‴, N‴ - hexaacetic Acid (H6ttha): Coordination Numbers 10 for [La(Httha)]2- and 9 for [Dy(Httha)]2- in their Guanidinium Salts

The lanthanum(III) and dysprosium(III) complexes of triethylenetetramine-N, N, N′, N″, N‴, N‴-hexaacetic acid (H6ttha) were prepared and isolated as guanidinium salts:[C(NH2)3]2[La(Httha)] · 3 H2O and [C(NH2)3]2[Dy(Httha)] · 5 H2O. The X-ray crystal structure of both complexes was determined: In the La(III) complex (space group P1̄) all donor atoms (N4O6) are coordinated. The coordination number 10 is realized in a bicapped square antiprism (SAPRS-10). The bond length La to O of the protonated carboxylic group is ca. 0.3 Å longer than the other five La-O distances. The Dy(III) complex (space group P1̄) exhibits coordination number 9 in a monocapped square antiprism (SAPRS-9). The protonated carboxylic group is not coordinated.