Menstrual cycle effects on selective attention and its underlying cortical networks

It was the aim of the present study to investigate menstrual cycle effects on selective attention and its underlying functional cerebral networks. Twenty-one healthy, right-handed, normally cycling women were investigated by means of functional magnetic resonance imaging using a go/no-go paradigm during the menstrual, follicular and luteal phase. On the behavioral level there was a significant interaction between visual half field and cycle phase with reaction times to right-sided compared to left-sided stimuli being faster in the menstrual compared to the follicular phase. These results might argue for a more pronounced functional cerebral asymmetry toward the left hemisphere in selective attention during the menstrual phase with low estradiol and progesterone levels. Functional imaging, however, did not reveal clear-cut menstrual phase-related changes in activation pattern in parallel to these behavioral findings. A functional connectivity analysis identified differences between the menstrual and the luteal phase: During the menstrual phase, left inferior parietal cortex showed a stronger negative correlation with the right middle frontal gyrus while the left medial frontal cortex showed a stronger negative correlation with the left middle frontal gyrus. These results can serve as further evidence of a modulatory effect of steroid hormones on networks of lateralized cognitive functions not only by interhemispheric inhibition but also by affecting intrahemispheric functional connectivity.

[Clostridium difficile infection (CDI) in the course of time - an issue only for the internist?]

BACKGROUND

Toxigenic strains of Clostridium (C.) difficile are the most prevalent pathogens of antibiotic associated intestinal disease and nosocomial diarrhoea. During the last 10 years, incidences of C. difficile infection (CDI) have increased worldwide.

MATERIALS AND METHODS

With clinical and microbiological original data for 2002-2012 from the University Hospitals Leipzig and Halle (Saale), Germany, the authors illustrate the current situation regarding CDI in the states of Saxony and Saxony-Anhalt and exemplify the latest developments in terms of incidence, prevalence of resistance, diagnosis and treatment strategies regarding CDI with an emphasis on surgical options.

RESULTS

Following the general trend, at the University Hospitals of Leipzig and Halle (Saale) there was also an increase in incidence of CDI, especially of severe clinical courses. In primary and secondary care facilities, prevention of CDI is based on hygiene management and restricted usage of antibiotics, preferably as "Antibiotic Stewardship" programmes. In 2012, the new macrocyclic antibiotic Fidaxomicin was approved in the European Union for the treatment of CDI. The therapeutic armamentarium, previously based on metronidazole or vancomycin, has now been enriched by a substance that presumably will reduce the rate of recurrence of CDI. Moreover, early data from case series and controlled trials suggest that the re-establishment of eubiosis in the colon of patients with recurrent CDI by stool transplantation from healthy donors is an alternative to antibiotics. Standard surgical intervention for refractory CDI is subtotal colectomy with terminal ileostomy. In patients with adequate life expectancy and without organ dysfunction, a colon-saving surgical technique should be considered.

CONCLUSION

Taking antibiotics for most remains the main risk factor for suffering from symptomatic CDI. With the introduction of Fidaxomicin there is hope for an improvement in the conservative treatment of CDI. Stool transplants from healthy donors are now considered to be better than giving antibiotics for severe CDI, but this treatment has not found broad acceptance yet. In cases with a lack of early treatment success, the surgeon must be consulted. Here, the evidence for preferably colon-saving surgical procedures is so far unfortunately low.

[Immunosuppressive treatment as a risk factor for the occurrence of clostridium difficile infection (CDI)]

BACKGROUND

Toxigenic Clostridium difficile strains are known as the most common infectious cause of antibiotic-associated intestinal disease and nosocomial diarrhoea. The increased incidence of hypervirulent strains gives rise to worldwide concern. In particular, courses with multiple recurrences are observed in the presence of immunosuppression.

METHODS

In this retrospective controlled observational study we aimed to determine immunosuppression as an independent risk factor for symptomatic CDI and to identify characteristics and differences of immunocompromised patients with respect to disease severity, disease progression, intestinal manifestations, recurrence rates and other factors. We compared symptoms and clinical features of 55 immunosuppressed patients with confirmed CDI with those of 50 patients without immunosuppressive medication (mean age 59.3 years ± 16.2 vs. 69.2 years ± 15.0) who were treated at the Departments of Internal Medicine I and IV of the University Hospital Halle (Saale), Germany, between 2006 and 2009. Multivariate analysis using binary logistic regression was performed for a control group of 105 patients without CDI. In this group, there were 62 patients without evidence of immunosuppression and 43 immunosuppressed patients (mean age 66.9 years ± 12.4 vs. 56.0 years ± 13.7).

RESULTS

The clinical courses of the two groups differed considerably. Immunosuppressed patients were significantly more frequently colonised with Clostridium difficile without clinically detectable manifestation or only mild clinical symptoms not requiring therapy (22 vs. 2 %, p = 0.003), while there were similar numbers of moderate (46 vs. 52 %, p = 0.503) but less severe CDI cases (27 vs. 40 %, p = 0.167). Relapses were observed more frequently in the group of immunosuppressed patients (15 vs. 6 %, p = 0.153). Multivariate analysis using logistic regression identified immunosuppression as an independent risk factor for CDI (OR = 2.75), in addition to prior antibiotic therapy (OR = 10.15) and PPI intake (OR = 2.93).

CONCLUSION

We conclude that immunosuppression has to be regarded as an independent risk factor for CDI. Immunosuppressive treatment increases the risk of colonisation and infection with Clostridium difficile and leads to a higher relapse rate in patients with CDI.

Emotional prosody modulates attention in schizophrenia patients with hallucinations

Recent findings have demonstrated that emotional prosody (EP) attracts attention involuntarily (Grandjean et al., 2008). The automat shift of attention toward emotionally salient stimuli can be overcome by attentional control (Hahn et al., 2010). Attentional control is impaired in schizophrenia, especially in schizophrenic patients with hallucinations because the "voices" capture attention increasing the processing load and competing for top-down resources. The present study investigates how involuntary attention is driven by implicit EP in schizophrenia with auditory verbal hallucinations (AVH) and without (NAVH). Fifteen AVH patients, 12 NAVH patients and 16 healthy controls (HC) completed a dual-task dichotic listening paradigm, in which an emotional vocal outburst was paired with a neutral vocalization spoken in male and female voices. Participants were asked to report the speaker's gender while attending to either the left or right ear. NAVH patients and HC revealed shorter response times for stimuli presented to the attended left ear than the attended right ear. This laterality effect was not present in AVH patients. In addition, NAVH patients and HC showed faster responses when the EP stimulus was presented to the unattended ear, probably because of less interference between the attention-controlled gender voice identification task and involuntary EP processing. AVH patients did not benefit from presenting emotional stimuli to the unattended ear. The findings suggest that similar to HC, NAVH patients show a right hemispheric bias for EP processing. AVH patients seem to be less lateralized for EP and therefore might be more susceptible to interfering involuntary EP processing; regardless which ear/hemisphere receives the bottom up input.

Expression of nogo-a is decreased with increasing gestational age in the human fetal brain

Nogo is a member of the reticulon family. Our understanding of the physiological functions of the Nogo-A protein has grown over the last few years, and this molecule is now recognized as one of the most important axonal regrowth inhibitors present in central nervous system (CNS) myelin. Nogo-A plays other important roles in nervous system development, epilepsy, vascular physiology, muscle pathology, stroke, inflammation, and CNS tumors. Since the exact role of Nogo-A protein in human brain development is still poorly understood, we studied its cellular and regional distribution by immunohistochemistry in the frontal lobe of 30 human fetal brains. Nogo-A was expressed in the following cortical zones: ependyma, ventricular zone, subventricular zone, intermediate zone, subplate, cortical plate, and marginal zone. The number of positive cells decreased significantly with increasing gestational age in the subplate and marginal zone. Using different antibodies, changes in isoform expression and dimerization states could be shown between various cortical zones. The results demonstrate a significant change in the expression of Nogo-A during the development of the human brain. The effects of its time- and region-specific regulation have to be further studied in detail.

Isolated leptomeningeal infiltration of a primary CNS B-cell lymphoma diagnosed by flow cytometry and confirmed by necropsy

BACKGROUND

The diagnosis of the isolated leptomeningeal involvement of a primary central nervous system B-cell lymphoma without parenchyma lesions may be difficult. Patients with leptomeningeal meningeosis lymphomatosa can present with various neurologic deficits.

AIMS OF THE STUDY

To demonstrate the impact of cerebrospinal fluid (CSF) flow cytometry in the diagnosis of an isolated leptomeningeal manifestation of B-cell lymphoma by presenting an interesting case report.

METHODS

Flow cytometric analysis of B-cell monoclonality of the CSF was performed as complementary diagnostic procedure in addition to CSF cytology. Final diagnosis was confirmed by necropsy.

RESULTS

We suspected isolated leptomeningeal manifestation of B-cell lymphoma with palsy of the VI and VII cranial nerves in a 79-year-old male, because of mononuclear pleocytosis in CSF. Interestingly, the decisive diagnostic hint was given by implementation of flow cytometry of the CSF. Diagnosis was confirmed by postmortem autopsy.

CONCLUSION

Our case shows that flow cytometry of the CSF in addition to conventional CSF cytology has the potential to accelerate diagnosis of lymphomeningeal infiltration of B-cell lymphoma.

Abstract 2919: Unexpected role of CRAF in tumor cell mitosis revealed by an allosteric inhibitor

RAF kinases regulate fundamental cellular processes such as proliferation and survival and can be mutated or dysregulated in tumors. Although, RAF inhibitors show clinical activity in some cancer patients, recent reports have shown that ATP-competitive RAF inhibitors can enhance the proliferation of RAS driven tumors by promoting B- and CRAF dimerization and phosphorylation of CRAF on serine 338. Recently, we characterized an allosteric inhibitor of RAF that disrupts RAF dimerization, CRAF serine 338 phosphorylation and tumor growth in mice. Here, we report the surprising finding that phospho-S338 CRAF localizes to the mitotic spindle of proliferating tumor cells in vitro and in biopsies from cancer patients. Importantly, treatment of these cells with an allosteric, but not an ATP-competitive inhibitor of RAF, prevents CRAF localization to the mitotic spindle and causes cell cycle arrest at pro-metaphase in a MAPK-independent manner. Mechanistically, phospho-S338 CRAF interacts and co-localizes with active Polo-like kinase 1 (Plk1) at the mitotic spindle of proliferating cells. In fact, allosteric or genetic inhibition of CRAF inhibits Plk1 activity and its accumulation at the kinetochores causing pro-metaphase arrest. These findings define an unexpected role for RAF in mitosis, revealing a novel mechanism for RAF as a therapeutic target in oncology.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2919. doi:10.1158/1538-7445.AM2011-2919

[Nosocomial diarrhea]

Hospital acquired or nosocomial diarrhea affects up to one third of hospitalized patients. It increases mortality rates as well as length and costs of the hospital stay. Drug side effects are the predominant cause of nosocomial diarrhea whilst clostridium difficile is the most common infectious agent, whose development is closely linked to antibiotic usage. The causal therapy of mild clostridium difficile infections is controversially discussed. Nevertheless, the use of Metronidazol for mild cases and of vancomycin for severe forms of the disease is recommended. Diarrhea outbreaks might be caused by viruses and less often by Salmonella and Listeria. Norovirus infections are of outstanding importance. Rehydration and isolation to prevent the spread of this highly contagious virus are the only reasonable options as we still lack a proper therapy.

Congenital prosopagnosia: multistage anatomical and functional deficits in face processing circuitry

Face recognition is a primary social skill which depends on a distributed neural network. A pronounced face recognition deficit in the absence of any lesion is seen in congenital prosopagnosia. This study investigating 24 congenital prosopagnosic subjects and 25 control subjects aims at elucidating its neural basis with fMRI and voxel-based morphometry. We found a comprehensive behavioral pattern, an impairment in visual recognition for faces and buildings that spared long-term memory for faces with negative valence. Anatomical analysis revealed diminished gray matter density in the bilateral lingual gyrus, the right middle temporal gyrus, and the dorsolateral prefrontal cortex. In most of these areas, gray matter density correlated with memory success. Decreased functional activation was found in the left fusiform gyrus, a crucial area for face processing, and in the dorsolateral prefrontal cortex, whereas activation of the medial prefrontal cortex was enhanced. Hence, our data lend strength to the hypothesis that congenital prosopagnosia is explained by network dysfunction and suggest that anatomic curtailing of visual processing in the lingual gyrus plays a substantial role. The dysfunctional circuitry further encompasses the fusiform gyrus and the dorsolateral prefrontal cortex, which may contribute to their difficulties in long-term memory for complex visual information. Despite their deficits in face identity recognition, processing of emotion related information is preserved and possibly mediated by the medial prefrontal cortex. Congenital prosopagnosia may, therefore, be a blueprint of differential curtailing in networks of visual cognition.

Systematic meta-analysis on percutaneous ethanol injection and percutaneous acid injection for the treatment of early HCC: A Cochrane analysis

e15657

Background: Hepatocellular carcinoma (HCC) is the fifth most common global cancer with high geographical variability. When HCC is detected early, percutaneous approaches such as percutaneous ethanol injection (PEI), percutaneous acetic acid injection (PAI), and radiofrequency thermal ablation (RFTA) have curative potential and represent low invasive alternatives to surgery. The role of percutaneous ethanol or acetic acid injection and other percutaneous interventions except RFTA has not been addressed in a systematic metaanalysis. The objective was to evaluate the effects of PEI and PAI for early HCC. Methods: A systematic search was performed in EMBASE, Cochrane Central, The Cochrane Hepato-Biliary Group Controlled Trials Register, Medline and Scopus as well as a handsearch of meeting abstracts. Only randomised controlled trials were included. RFTA studies were not considered. Primary endpoint was overall survival, secondary endpoints were cancer free survival, number and type of adverse events, duration of hospital stay, and quality of life. Results: 3 studies covering 261 patients were identified. Two studies compared PEI with PAI. 91 and 94 patients with one to three HCC-nodules ≤ 3cm underwent PEI and PAI, respectively. Overall survival (HR 1.47; 95% CI 0.68 to 3.19) and cancer free survival (HR 1.42; 95% CI 0.68 to 2.94) were not significantly different after treatment by PEI versus PAI. Both treatments were safe with no serious adverse events reported and modest pain being the most frequent adverse event. Data on the duration of hospital stay were inconclusive and data on quality of life not available. One study compared PEI with surgery. 38 patients were allocated to each treatment arm. There was no significant difference in survival (HR 1.57; 95% CI 0.53 to 4.61) and cancer free survival (HR 1.35; 95% CI 0.69 to 2.63). No serious adverse events were reported in the PEI group but 3 postoperative deaths occurred in the surgery arm. Conclusions: PEI and PAI are similarly effective and safe in patients with one to three small (≤ 3 cm) HCC nodules. Although the evidence is weaker, the beneficial effect of PEI is comparable to that of segmental liver resection and thus should be used preferentially due to its low morbidity and mortality.

No significant financial relationships to disclose.

Retinal vascular permeability suppression by topical application of a novel VEGFR2/Src kinase inhibitor in mice and rabbits

Retinal and choroidal vascular diseases, with their associated abnormalities in vascular permeability, account for the majority of patients with vision loss in industrialized nations. VEGF is upregulated in ischemic retinopathies such as diabetes and is known to dramatically alter vascular permeability in a number of nonocular tissues via Src kinase-regulated signaling pathways. VEGF antagonists are currently in clinical use for treating the new blood vessels and retinal edema associated with neovascular eye diseases, but such therapies require repeated intraocular injections. We have found that vascular leakage following intravitreal administration of VEGF in mice was abolished by systemic or topical delivery of what we believe is a novel VEGFR2/Src kinase inhibitor; this was confirmed in rabbits. The relevance of Src inhibition to VEGF-associated alterations in vascular permeability was further substantiated by genetic studies in which VEGF injection or laser-induced vascular permeability failed to augment retinal vascular permeability in Src-/- and Yes-/- mice (Src and Yes are ubiquitously expressed Src kinase family members; Src-/- and Yes-/- mice lacking expression of these kinases show no vascular leak in response to VEGF). These findings establish a role for Src kinase in VEGF-mediated retinal vascular permeability and establish a potentially safe and painless topically applied therapeutic option for treating vision loss due to neovascular-associated retinal edema.

Abstract 4740: Selective ablation of metastatic disease with integrin ανβ3 targeted nanoparticle drug delivery

Angiogenic blood vessels found within growing tumors express high levels of integrin ανβ3 while mature vessels fail to express this integrin. Based on this we developed a ανβ3-targeted nanoparticle (NP) in an attempt to selectively deliver therapeutics to the tumor neovasculature. A cyclic peptide ligand (cRGDfK) coupled to a phospholipid and incorporated into a nanoparticle demonstrated specific binding to ανβ3 on cultured endothelial cells. To characterize the in vivo targeting capacity of these NPs, we monitored NP accumulation using intravital microscopy of tumor neovasculature. A dorsal skin-fold window chamber implanted with GFP-labeled melanoma cells lacking integrin ανβ3 were imaged at various times after NP injection into the bloodstream. By 5h post injection, the cRGDfK NPs targeted the neovasculature at the angiogenic tips adjacent to the tumor margin, whereas untargeted (cRADfK) NPs failed to bind. After establishing in vivo targeting, these ανβ3-targeted NPs were loaded with doxorubicin via an ammonium phosphate gradient for therapeutic studies. The cRGD-Dox particles disrupted angiogenesis in the mouse matrigel model leaving only small fragments of disrupted vessels within the FGF loaded plugs. Next, we utilized an orthotopic pancreatic cancer model to study the ability of the NPs to target the vasculature of both primary pancreatic tumors as well as metastatic sites including the hepatic hilar lymph node and mesenteric lymph nodes. cRGD-Dox particles injected systemically at 1 mg/kg produced a profound anti-metastatic effect while only marginally influencing the pre-established primary tumor within the pancreas. This is much improved compared to the free doxorubicin treatments in which 1 mg/kg of free doxorubicin had no effect and 15 mg/kg of free doxorubicin was required for a similar therapeutic effect in this orthotopic model. Animals treated with 15 mg/kg of free doxorubicin lost over 20% of their body weight within 7 days, whereas no decrease in body weight was observed in the cRGD-Dox treated animals, confirming the reduction in overall toxicity. Histology confirmed that the cRGD-Dox particles induced apoptosis in regions co-localized with β3 expressing tumor vasculature. Additionally, we tested the cRGD-Dox particles in an orthotopic renal cell carcinoma model. Similar to the pancreatic carcinoma, the cRGD-Dox particles had a slight effect on primary tumor growth but greatly reduced metastasis to several sites including the pancreas, liver, spleen, and diaphragm. These findings reveal that ανβ3 targeted NP drug delivery may preferentially disrupt newly forming metastatic lesions by delivery of chemotherapeutic agents to sites of active angiogenesis in which the endothelium expresses high levels of ανβ3.