Multispectral characterization of tissues encountered during laparoscopic colorectal surgery

AimsThis study investigated the feasibility of automated differentiation between essential tissue types encountered during laparoscopic colorectal surgery using spectral analysis.MethodsWide band (440–1830 nm) spectra were collected using an optical fiber probe and spectrometer from freshly explanted, ex vivo, human colonic specimens. These data were normalized at 810 nm (an isobestic wavelength for hemoglobin and oxy-hemoglobin) and mathematically analyzed using total principal component regression (TPCR).Results929 spectra were collected from specimens of 19 patients, distinguishing 5 tissue types: mesenteric fat (MF, n = 269), blood vessels (BV, n = 377), colonic tissue (CT, n = 213), ureter (UR, n = 10) and tumorous tissue in colon (TT, n = 60). For each individual tissue type the distinctive ability was determined against all other tissue types pooled as a group. Paired probability density function (PDF) of “tissue” (centered around label 1) versus “all other pooled tissues” (centered around label 0) and the cumulative distribution function (CDF) at label crossover value 0.5 was determined for each tissue type (MF: CDF = 0.99 [SD = 0.19]; BV: CDF = 0.95 [SD = 0.29]; CT: CDF = 0.98 [SD = 0.22]; UR: CDF = 0.99 [SD = 0.09]; TT: CDF = 0.99 [SD = 0.18]).ConclusionAutomated spectral differentiation of blood vessel, ureter, mesenteric adipose tissue, colonic tissue and tumorous tissue in colon, is feasible in freshly explanted human colonic specimens. These results may be exploited for further steps toward multi- or hyperspectrally enhanced in vivo (laparoscopic) surgical imaging.     

MIC and serum bactericidal activity of clindamycin against methicillin-resistant and -sensitive Staphylococci

Summary Six volunteers were given 600 mg clindamycin intravenously to investigate the serum bactericidal activity (SBA) against 50 methicillin susceptible (MSSA) and 50 methicillin resistantStaphylococcus aureus (MRSA) strains. Minimal inhibitory concentrations (MIC) against MSSA, MRSA and 50 methicillin resistant strains ofStaphylococcus epidermidis (MRSE), of which 50% were slime-producing, were determined. SBA of clindamycin against MSSA and MRSA was equally high (mean reciprocal SBA titer against MSSAvs MRSA 1h after application was 13.0vs 13.45), although MICs against MRSA were markedly higher than against MSSA (MIC 90 of MRSAvs MSSA: 0.06vs>32 mg/l). There was no difference in MICs between slime- and non-slime-producing MRSE.

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MHK und Serumbakterizidie von Clindamycin gegen methicillinresistente und -empfindliche Staphylokokken

Zusammenfassung In dieser Studie wurde dieIn-vivo-Aktivität von Clindamycin gegen 50 Oxacillin-sensible (MSSA) und 50 Oxacillin-resistenteStaphylococcus aureus(MRSA-)Stämme mit dem Serumbakterizidie-Test/(SBA) untersucht. Sechs Probanden wurde einmalig 600 mg Clindamycin intravenös infundiert. Weiterhin wurde die minimale Hemmkonzentration (MHK) von Clindamycin gegen 50 Oxacillin-sensible und -resistenteS. aureus und 50 Oxacillin-resistenteStaphylococcus epidermidis-Stämme, von welchen die Hälfte Schleim produzierten, bestimmt. Clindamycin hatte eine gleich hohe Serumbakterizidie gegen Oxacillin-sensible und-resistenteS. aureus-Stämme (durchschnittlicher reziproker SBA Titer von MSSAvs MRSA 1h nach Applikation: 13,0vs 13,45), obwohl die MHK-Werte gegen die Oxacillin-sensiblenS. aureus deutlich geringer waren (MHK 90 von MSSAvs MRSA: 0,06vs 32 mg/l). Die MHK-Werte gegen die Oxacillin-resistentenS. epidermidis-Stämme waren ebenfalls niedrig, ein Unterschied zwischen Schleim-, beziehungsweise nicht schleimproduzierenden Stämmen bestand nicht.

     

Structural Variations of the Cell Wall Precursor Lipid II and Their Influence on Binding and Activity of the Lipoglycopeptide Antibiotic Oritavancin

Oritavancin is a semisynthetic derivative of the glycopeptide antibiotic chloroeremomycin with activity against Gram-positive pathogens, including vancomycin-resistant staphylococci and enterococci. Compared to vancomycin, oritavancin is characterized by the presence of two additional residues, a hydrophobic 4′-chlorobiphenyl methyl moiety and a 4-epi-vancosamine substituent, which is also present in chloroeremomycin. Here, we show that oritavancin and its des-N-methylleucyl variant (des-oritavancin) effectively inhibit lipid I- and lipid II-consuming peptidoglycan biosynthesis reactions in vitro. In contrast to that for vancomycin, the binding affinity of oritavancin to the cell wall precursor lipid II appears to involve, in addition to the d-Ala-d-Ala terminus, other species-specific binding sites of the lipid II molecule, i.e., the crossbridge and d-isoglutamine in position 2 of the lipid II stem peptide, both characteristic for a number of Gram-positive pathogens, including staphylococci and enterococci. Using purified lipid II and modified lipid II variants, we studied the impact of these modifications on the binding of oritavancin and compared it to those of vancomycin, chloroeremomycin, and des-oritavancin. Analysis of the binding parameters revealed that additional intramolecular interactions of oritavancin with the peptidoglycan precursor appear to compensate for the loss of a crucial hydrogen bond in vancomycin-resistant strains, resulting in enhanced binding affinity. Augmenting previous findings, we show that amidation of the lipid II stem peptide predominantly accounts for the increased binding of oritavancin to the modified intermediates ending in d-Ala-d-Lac. Corroborating our conclusions, we further provide biochemical evidence for the phenomenon of the antagonistic effects of mecA and vanA resistance determinants in Staphylococcus aureus, thus partially explaining the low frequency of methicillin-resistant S. aureus (MRSA) acquiring high-level vancomycin resistance.     

Disease Detection or Public Opinion Reflection? Content Analysis of Tweets,Other Social Media,and Online Newspapers During the Measles Outbreak in the Netherlands in 2013

Background

In May 2013, a measles outbreak began in the Netherlands among Orthodox Protestants who often refuse vaccination for religious reasons.

Objective

Our aim was to compare the number of messages expressed on Twitter and other social media during the measles outbreak with the number of online news articles and the number of reported measles cases to answer the question if and when social media reflect public opinion patterns versus disease patterns.

Methods

We analyzed measles-related tweets, other social media messages, and online newspaper articles over a 7-month period (April 15 to November 11, 2013) with regard to topic and sentiment. Thematic analysis was used to structure and analyze the topics.

Results

There was a stronger correlation between the weekly number of social media messages and the weekly number of online news articles (P<.001 for both tweets and other social media messages) than between the weekly number of social media messages and the weekly number of reported measles cases (P=.003 and P=.048 for tweets and other social media messages, respectively), especially after the summer break. All data sources showed 3 large peaks, possibly triggered by announcements about the measles outbreak by the Dutch National Institute for Public Health and the Environment and statements made by well-known politicians. Most messages informed the public about the measles outbreak (ie, about the number of measles cases) (93/165, 56.4%) followed by messages about preventive measures taken to control the measles spread (47/132, 35.6%). The leading opinion expressed was frustration regarding people who do not vaccinate because of religious reasons (42/88, 48%).

Conclusions

The monitoring of online (social) media might be useful for improving communication policies aiming to preserve vaccination acceptability among the general public. Data extracted from online (social) media provide insight into the opinions that are at a certain moment salient among the public, which enables public health institutes to respond immediately and appropriately to those public concerns. More research is required to develop an automatic coding system that captures content and user’s characteristics that are most relevant to the diseases within the National Immunization Program and related public health events and can inform official responses.     

Cantú Syndrome Resulting from Activating Mutation in the KCNJ8 Gene

ATP‐sensitive potassium (K_ATP) channels, composed of inward‐rectifying potassium channel subunits (Kir6.1 and Kir6.2, encoded by KCNJ8 and KCNJ11, respectively) and regulatory sulfonylurea receptor (SUR1 and SUR2, encoded by ABCC8 and ABCC9, respectively), couple metabolism to excitability in multiple tissues. Mutations in ABCC9 cause Cantú syndrome (CS), a distinct multiorgan disease, potentially via enhanced K_ATP channel activity. We screened KCNJ8 in an ABCC9 mutation‐negative patient who also exhibited clinical hallmarks of CS (hypertrichosis, macrosomia, macrocephaly, coarse facial appearance, cardiomegaly, and skeletal abnormalities). We identified a de novo missense mutation encoding Kir6.1[p.Cys176Ser] in the patient. Kir6.1[p.Cys176Ser] channels exhibited markedly higher activity than wild‐type channels, as a result of reduced ATP sensitivity, whether coexpressed with SUR1 or SUR2A subunits. Our results identify a novel causal gene in CS, but also demonstrate that the cardinal features of the disease result from gain of K_ATP channel function, not from a Kir6‐independent SUR2 function.     

Advances in radiotherapy and targeted therapies for rectal cancer

The last decade witnessed a significant progress in understanding the biology and immunology of colorectal cancer alongside with the technical innovations in radiotherapy.The stepwise implementation of intensitymodulated and image-guided radiation therapy by means of megavolt computed tomography and helical tomotherapy enabled us to anatomically sculpt dose delivery,reducing treatment related toxicity.In addition,the administration of a simultaneous integrated boost offers excellent local control rates.The novel challenge is the development of treatment strategies for medically inoperable patient and organ preserving approaches.However,distant control remains unsatisfactory and indicates an urgent need for biomarkers that predict the risk of tumor spread.The expected benefit of target?ed therapies that exploit the tumor genome alone is so far hindered by high cost techniques and pharmaceuticals,hence hardly justifying rather modest improvements in patient outcomes.On the other hand,the immune landscape of colorectal cancer is now better clarified with regard to the immunosuppressive network that promotes immune escape.Both N2 neutrophils and myeloid-derived suppressor cells(MDSC)emerge as useful clinical biomarkers of poor prognosis,while the growing list of anti-MDSC agents shows promising ability to boost antitumor T-cell immunity in preclinical settings.Therefore,integration of genetic and immune biomarkers is the next logical step towards effective targeted therapies in the context of personalized cancer treatment.     

Locally-Delivered T-Cell-Derived Cellular Vehicles Efficiently Track and Deliver Adenovirus Delta24-RGD to Infiltrating Glioma

Oncolytic adenoviral vectors are a promising alternative for the treatment of glioblastoma. Recent publications have demonstrated the advantages of shielding viral particles within cellular vehicles (CVs), which can be targeted towards the tumor microenvironment. Here, we studied T-cells, often having a natural capacity to target tumors, for their feasibility as a CV to deliver the oncolytic adenovirus, Delta24-RGD, to glioblastoma. The Jurkat T-cell line was assessed in co-culture with the glioblastoma stem cell (GSC) line, MGG8, for the optimal transfer conditions of Delta24-RGD in vitro. The effect of intraparenchymal and tail vein injections on intratumoral virus distribution and overall survival was addressed in an orthotopic glioma stem cell (GSC)-based xenograft model. Jurkat T-cells were demonstrated to facilitate the amplification and transfer of Delta24-RGD onto GSCs. Delta24-RGD dosing and incubation time were found to influence the migratory ability of T-cells towards GSCs. Injection of Delta24-RGD-loaded T-cells into the brains of GSC-bearing mice led to migration towards the tumor and dispersion of the virus within the tumor core and infiltrative zones. This occurred after injection into the ipsilateral hemisphere, as well as into the non-tumor-bearing hemisphere. We found that T-cell-mediated delivery of Delta24-RGD led to the inhibition of tumor growth compared to non-treated controls, resulting in prolonged survival (p = 0.007). Systemic administration of virus-loaded T-cells resulted in intratumoral viral delivery, albeit at low levels. Based on these findings, we conclude that T-cell-based CVs are a feasible approach to local Delta24-RGD delivery in glioblastoma, although efficient systemic targeting requires further improvement.