ARF6 is a host factor for SARS-CoV-2 infection in vitro

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a newly emerged beta-coronavirus that enter cells via two routes, direct fusion at the plasma membrane or endocytosis followed by fusion with the late endosome/lysosome. While the viral receptor, ACE2, multiple entry factors and the mechanism of fusion of the virus at the plasma membrane have been investigated extensively, viral entry via the endocytic pathway is less understood. By using a human hepatocarcinoma cell line, Huh-7, which is resistant to the antiviral action of the TMPRSS2 inhibitor camostat, we discovered that SARS-CoV-2 entry is not dependent on dynamin but on cholesterol. ADP-ribosylation factor 6 (ARF6) has been described as a host factor for SARS-CoV-2 replication and is involved in the entry and infection of several pathogenic viruses. Using CRISPR/Cas9 genetic deletion, a modest reduction in SARS-CoV-2 uptake and infection in Huh-7 was observed. In addition, pharmacological inhibition of ARF6 with the small molecule NAV-2729 showed a dose-dependent reduction of viral infection. Importantly, NAV-2729 also reduced SARS-CoV-2 viral loads in more physiological models of infection: Calu-3 cells and kidney organoids. This highlighted a role for ARF6 in multiple cell contexts. Together, these experiments point to ARF6 as a putative target to develop antiviral strategies against SARS-CoV-2.

ARF6 is a host factor for SARS-CoV-2 infection in vitro

SARS-CoV-2 is a newly emerged beta-coronavirus that enter cells via two routes, direct fusion at the plasma membrane or endocytosis followed by fusion with the late endosome/lysosome. While the viral receptor, ACE2, multiple entry factors, and the mechanism of fusion of the virus at the plasma membrane have been extensively investigated, viral entry via the endocytic pathway is less understood. By using a human hepatocarcinoma cell line, Huh-7, which is resistant to the antiviral action of the TMPRSS2 inhibitor camostat, we discovered that SARS-CoV-2 entry is not dependent on dynamin but dependent on cholesterol. ADP-ribosylation factor 6 (ARF6) has been described as a host factor for SARS-CoV-2 replication and it is involved in the entry and infection of several pathogenic viruses. Using CRISPR-Cas9 genetic deletion, we observed that ARF6 is important for SARS-CoV-2 uptake and infection in Huh-7. This finding was corroborated using a pharmacologic inhibitor, whereby the ARF6 inhibitor NAV-2729 showed a dose-dependent inhibition of viral infection. Importantly, NAV-2729 reduced SARS-CoV-2 viral loads also in more physiologic models of infection: Calu-3 and kidney organoids. This highlighted the importance of ARF6 in multiple cell contexts. Together, these experiments points to ARF6 as a putative target to develop antiviral strategies against SARS-CoV-2.

Immune and stem cell compartments of acetabular and femoral bone marrow in hip osteoarthritis patients

OBJECTIVE

Hip osteoarthritis (OA) affects all components of the osteochondral unit, leading to bone marrow (BM) lesions, and unknown consequences on BM cell functionality. We analyzed the cellular composition in OA-affected acetabula compared to proximal femur shafts obtained of hip OA patients to reveal yet not explored immune and stem cell compartments.

DESIGN

Combining flow cytometry, cellular assays and transcription analyses, we performed extensive ex vivo phenotyping of acetabular BM cells from 18 hip OA patients, comparing them with their counterparts from patient-matched femoral shaft BM samples. Findings were related to differences in skeletal sites and age.

RESULTS

Acetabular BM had a greater frequency of T-lymphocytes, non-hematopoietic cells and colony-forming units fibroblastic potential than femoral BM. The incidence of acetabular CD45⁺CD3⁺ T-lymphocytes increased (95% CI: 0.1770 to 0.0.8416), while clonogenic hematopoietic progenitors declined (95% CI: -0.9023 to -0.2399) with age of patients. On the other side, in femoral BM, we observed higher B-lymphocyte, myeloid and erythroid cell frequencies. Acetabular mesenchymal stromal cells (MSCs) showed a senescent profile associated with the expression of survival and inflammation-related genes. Efficient osteogenic and chondrogenic differentiation was detected in acetabular MSCs, while adipogenesis was more pronounced in their femoral counterparts.

CONCLUSION

Our results suggest that distinctions in BM cellular compartments and MSCs may be due to the influence of the OA-stressed microenvironment, but also acetabular vs femoral shaft-specific peculiarities cannot be excluded. These results bring new knowledge on acetabular BM cell populations and may be addressed as novel pathogenic mechanisms and therapeutic targets in OA.

TNF-α and its soluble receptors mediate the relationship between prior severe mood episodes and cognitive dysfunction in euthymic bipolar disorder

BACKGROUND

Bipolar disorder (BD) is one of the most disabling mental health conditions in the world. Symptoms of cognitive impairment in BD contribute directly to occupational and social deficiencies and are very difficult to treat. Converging evidence suggests that BD patients have increased peripheral markers of inflammation. The hypothesis of neuroprogression in BD postulates that cognitive deficits develop over the course of the illness and are influenced by prior severe mood episodes, leading to wear-and-tear on the brain- however, there exists a paucity of data statistically testing a mediating role of immune molecules in cognitive dysfunction in BD.

METHODS

This is a cross-sectional study. We measured serum levels of tumor necrosis factor alpha (TNF-α), and soluble (s) TNF receptors one and two (sTNF-R1 and sTNF-R2) in 219 euthymic BD patients and 52 Healthy Controls (HCs). Structural equation modeling (SEM) was used for the primary purpose of assessing whether TNF markers (measured by the multiple indicators TNF-α, sTNF-R1 and sTNF-R2) mediate the effect or number of prior severe mood episodes (number of prior psychiatric hospitalizations) on cognitive performance.

RESULTS

BD and HC groups did not differ on circulating levels of TNF molecules in the present study. However, we found higher sTNF-R1 concentration in 'late-stage' BD illness (>1 prior psychiatric hospitalization) compared to those in early stage illness. In the subsequent SEM, we found that the model fits the data acceptably (Chi-square = 49.2, p = 0.3), and had a 'close fit' (RMSEA = 0.02, PCLOSE = 0.9). Holding covariates constant (age, sex, premorbid IQ, education, and race), we found that the standardized indirect effect was significant, p = 0.015, 90%CI [-0.07, -0.01], indicating that the estimated model was consistent with peripheral TNF markers partially mediating a causal effect of severe mood episodes on executive function.

CONCLUSIONS

Our results indicate that circulating levels of TNF molecules partially mediate the relationship between prior severe mood episodes and executive function in BD. These results may implicate TNF variables in the neuroprogressive course of BD and could point to novel interventions for cognition.

Modulation of tactile perception by Virtual Reality distraction: The role of individual and VR-related factors

Background

Virtual reality (VR) has shown to be an effective distraction method in health care. However, questions remain regarding individual and VR-related factors that may modulate the effect of VR.

Purpose

To explore the effect of VR distraction on tactile perception thresholds in healthy volunteers, in relation to personal characteristics and interactivity of VR applications.

Methods

A randomized three way cross-over study was conducted to investigate the effects of active and passive VR applications in 50 healthy participants. Main outcome measures were monofilament detection thresholds (MDT) and electrical detection thresholds (EDT). Personal characteristics (e.g. age, gender, susceptibility for immersion) and immersion in the VR conditions were analyzed for their effect on VR induced threshold differences.

Results

The use of VR caused a significant increase in both MDT and EDT compared to the control condition (MDT: F (2, 76) = 20.174, p < 0.001; EDT F (2, 76) = 6.907, p = 0.002). Furthermore, a significant difference in favour of active VR compared to passive VR was found in MDT (p = 0.012), but not in EDT. No significant gender effect was found. There was a significant positive correlation between age and active VR distraction (r = 0.333, p = 0.018). Immersion in the VR world was positively correlated with the effect of VR, whereas visualization and daydreaming were negatively correlated with VR effects.

Conclusion

VR increased tactile perception thresholds, with active VR having the largest effect. Results indicate that the efficacy of VR may increase with increasing age. Gender did not affect VR susceptibility.

Hierarchical collective motion of a mixture of active dipolar Janus particles and passive charged colloids in two dimensions

We use computer simulations to study the behavior of a mixture of large passive charged colloids in a suspension of smaller active dipolar Janus particles. We find that when a single charged colloid is present in solution, it acquires a rotational or translational motion depending on how the active dipoles self-assemble on its surface to form active complexes. The collective behavior of these complexes is quite remarkable, and includes swarming behavior and coherent macroscopic motion. We detail how the variety of different phenomenologies emerging in this system can ultimately be controlled by the strength of the active forces and the relative concentration of the two species.

RNase 7 downregulates TH2 cytokine production by activated human T cells

BACKGROUND

The antimicrobial peptide (AMP) RNase 7 is constitutively expressed in the epidermis of healthy human skin and has been found to be upregulated in chronic inflammatory skin diseases such as atopic dermatitis and psoriasis. Activated T cells in lesional skin of patients with atopic dermatitis (AD) and psoriasis (PSO) might be directly exposed to RNase 7. In addition to their antimicrobial activity, immunoregulatory functions have been published for several AMPs. In this study, we investigated immunoregulatory effects of the antimicrobial peptide RNase 7 on activated T cells.

METHODS

Isolated human CD3+T cells were stimulated with RNase 7 and screened for possible effects by mRNA microarray analysis. The results of the mRNA microarray were confirmed in isolated CD4+T cells and in polarized TH2 cells using skin-derived native RNase 7 and a recombinant ribonuclease-inactive RNase 7 mutant. Activation of GATA3 was analysed by electrophoretic mobility shift assay.

RESULTS

Treatment of activated human CD4+T cells and TH2 cells with RNase 7 selectively reduced the expression of TH2 cytokines (IL-13, IL-4 and IL-5). Experiments with a ribonuclease-inactive recombinant RNase 7 mutant showed that RNase 7 ribonuclease activity is dispensable for the observed regulatory effect. We further demonstrate that CD4+T cells from AD patients revealed a significantly less pronounced downregulation of IL-13 in response to RNase 7 compared to healthy control. Finally, we show that GATA3 activation was diminished upon cultivation of T cells with RNase 7.

CONCLUSION

Our data indicate that RNase 7 has immunomodulatory functions on TH2 cells and decreases the production of TH2 cytokines in the skin.

Activity-induced collapse and reexpansion of rigid polymers

We study the elastic properties of a rigid filament in a bath of self-propelled particles. We find that while fully flexible filaments swell monotonically upon increasing the strength of the propelling force, rigid filaments soften for moderate activities, collapse into metastable hairpins for intermediate strengths, and eventually reexpand when the strength of the activity of the surrounding fluid is large. This collapse and reexpansion of the filament with the bath activity is reminiscent of the behavior observed in polyelectrolytes in the presence of different concentrations of multivalent salt.

Multicentre phase II trial of trastuzumab and capecitabine in patients with HER2 overexpressing metastatic pancreatic cancer

Background:

New therapeutic options for metastatic pancreatic cancer are urgently needed. In pancreatic cancer, overexpression of the epidermal growth factor receptor 2 (HER2) has been reported in up to 45%. This multicentre phase II study investigated the efficacy and toxicity of the HER2 antibody trastuzumab combined with capecitabine in the patients with pancreatic cancer and HER2 overexpression.

Methods:

Primary endpoint was progression-free survival (PFS) after 12 weeks. A total of 212 patients were screened for HER2 expression.

Results:

Immunohistochemical (IHC) HER2 expression was: 83 (40%) grade 0, 71 (34%) grade 1, 31 (15%) grade 2, 22 (11%) grade 3. A total of 17 patients with IHC +3 HER2 expression or gene amplification could be assessed for the treatment response. Grade 3/4 treatment toxicities were: each 7% leucopenia, diarrhoea, nausea and hand-foot syndrome. Progression-free survival after 12 weeks was 23.5%, median overall survival (OS) 6.9 months.

Conclusion:

This study demonstrates +3 HER2 expression or gene amplification in 11% of patients. Contrary to breast and gastric cancer, only 7 out of 11 (64%) patients with IHC +3 HER2 expression showed gene amplification. Although the therapy was well tolerated, PFS and OS did not perform favourably compared with standard chemotherapy. Together, we do not recommend further evaluation of anti-HER2 treatment in patients with metastatic pancreatic cancer.

KRAS mutation in metastatic pancreatic ductal adenocarcinoma: results of a multicenter phase II study evaluating efficacy of cetuximab plus gemcitabine/oxaliplatin (GEMOXCET) in first-line therapy

BACKGROUND

Genetic alterations within the epidermal growth factor receptor (EGFR) pathway, including KRAS mutations, have been demonstrated to be associated with response to EGFR inhibitors like cetuximab in colorectal cancers. Mutations in the KRAS gene have been found in 70-90% of pancreatic cancers. Unfortunately, the addition of cetuximab to chemotherapy did not increase response or survival in patients with advanced pancreatic cancer in phase II and phase III studies. The aim of this study was to evaluate the relationship between KRAS mutations and response or survival in patients with metastatic pancreatic cancer treated with cetuximab plus chemotherapy.

METHODS

Within a multicenter phase II trial, 64 patients with metastatic pancreatic cancer were treated with cetuximab in combination with gemcitabine and oxaliplatin until disease progression. Analyses of the EGFR pathway, including KRAS mutations, could be performed in 25 patients. Analyses were carried out following microdissection of the tumor.

RESULTS

Fourteen (56%) of the 25 patients examined harbored a point mutation in codon 12 of the KRAS gene. No differences between the groups were noted in median progression-free survival (104 days in KRAS wild-type patients vs. 118 days in patients with KRAS mutations). Overall survival was longer in wild-type patients compared to patients with KRAS mutations (263 vs. 162 days), but the difference did not reach statistical significance. A further analysis of our clinical phase II trial showed that the presence of a rash was significantly correlated with overall survival.

CONCLUSIONS

KRAS mutation in codon 12 may be associated with reduced survival compared to KRAS wild type. The role of KRAS mutations for cetuximab therapy in pancreatic cancer warrants further investigation in larger trials to exclude an epiphenomenon. Furthermore, the development of a rash is indicative of clinical benefit.

Endoscopic diagnosis of acute intestinal GVHD following allogeneic hematopoietic SCT: a retrospective analysis in 175 patients

Diagnosis of acute intestinal GVHD (aGVHD) following allogeneic hematopoietic cell transplantation is based on clinical symptoms and histological lesions. This retrospective analysis aimed to validate the 'Freiburg Criteria' for the endoscopic grading of intestinal aGVHD. Grade 1: no clear-cut criteria; grade 2: spotted erythema; grade 3: aphthous lesions; and grade 4: confluent defects, ulcers, denudation of the mucosa. Having excluded patients with infectious diarrhea, we evaluated 175 consecutive patients between January 2001 and June 2009. Setting a cutoff between grade 1 (no change in therapy) and grade 2 (intensification of immunosuppression), macroscopy had a sensitivity of 89.2% (95% confidence interval (CI): 80.4-94.9%), a specificity of 79.4% (95% CI: 69.6-87.1%), a positive-predictive value of 79.6% (95% CI: 70.0-87.2%) and a negative-predictive value of 89.0% (95% CI: 80.2-94.9%). In all, 20% of patients with aGVHD in the lower gastrointestinal tract (GIT) had lesions only in the terminal ileum. In all patients with aGVHD ≥2 of the upper GIT, typical lesions were also found in the lower GIT. Ileo-colonoscopy showed the highest diagnostic yield for aGVHD. In conclusion, the 'Freiburg Criteria' for macroscopic diagnosis of intestinal aGVHD provide high accuracy for identifying aGVHD ≥2.

Numbers and distribution of immune cells in the tunica mucosa of the small and large intestine of full-thickness biopsies from healthy pet cats

In this study, CD3(+) T lymphocytes and IgA(+) , IgG(+) and IgM(+) plasma cells were quantified in the tunica mucosa of the intestinal tract of 12 pet cats without gastrointestinal diseases. The study included full-thickness biopsies of the duodenum, jejunum, ileum and colon. The distribution and quantification of CD3(+) T cells, IgA(+) , IgG(+) and IgM(+) plasma cells within the intestinal tunica mucosa was performed by using immunohistochemical methods and computer-aided morphometry. CD3(+) T cells were significantly prominent in the villi and their numbers increased from duodenum to ileum but decreased towards the colon. The predominant type of plasma cells was IgA(+) cells, followed by IgM(+) cells. The number of IgG(+) cells was generally low compared to the other plasma cell types investigated. The results of the vertical distribution showed that IgA(+) and IgM(+) plasma cells were most numerous in the lower crypt areas, whilst IgG(+) plasma cells accumulated in the upper crypt region with a decline towards the villi and the lower crypt areas of control cats. All types of plasma cells showed a general decline from the duodenum towards the caudal sections of the intestinal tract regarding the horizontal distribution of plasma cells. This study provides a comprehensive overview on the vertical and horizontal distribution and the number of CD3(+) T cells and IgA(+) , IgG(+) and IgM(+) plasma cells in the intestinal tunica mucosa of pet cats.

Human hair follicle epithelium has an antimicrobial defence system that includes the inducible antimicrobial peptide psoriasin (S100A7) and RNase 7

BACKGROUND

Hair follicle (HF) ostia represent a potential port of microbial entry into the skin. However, they rarely show clinical signs of infection. This suggests the presence of local, efficient, antimicrobial defence systems, which may include antimicrobial peptides (AMPs).

OBJECTIVES

We determined the presence and distribution of the major AMPs, RNase 7 and psoriasin (S100A7), in human scalp HFs. We investigated whether HF production of these AMPs was induced by prototypic microbial products and proinflammatory cytokines, i.e. interferon (IFN)-gamma. Finally, we examined whether the classical pathways for AMP induction, such as toll-like receptor (TLR)4 and TLR5 expression, are present in human HFs and up-regulated after stimulation with bacterium-associated ligands.

METHODS

Cryosections from fresh or organ-cultured full-thickness normal human scalp skin treated with lipopolysaccharide (LPS), flagellin, protein A, lipoteichoic acid (LTA) or IFN-gamma were stained for psoriasin and RNase 7 immunoreactivity (IR) as well as for TLR4 and TLR5. In addition, outer root sheath cell culture and semiquantitative analysis of mRNA expression levels of RNase 7 and psoriasin were performed.

RESULTS

Specific RNase 7 IR was present throughout the entire HF outer root sheath in situ and in cell culture, whereas psoriasin IR was present only in the most distal compartment and not detectable in cultured ORS cells. Upon treatment with Gram-positive (LTA, protein A) or Gram-negative bacterial (LPS, flagellin) cell wall components, or with the cytokine IFN-gamma, the IR of both psoriasin and RNase 7 was modified. TLR4 and TLR5 IR was detected in the normal HF epithelium and were upregulated after treatment with their respective ligand. The mRNA analysis confirmed the immunohistochemistry results.

CONCLUSIONS

This pilot study suggests that normal human scalp HF epithelium possesses a functional antimicrobial defence system, which includes the AMPs RNase 7 and psoriasin, and TLRs, and that these are induced by classical microbial products.

Cetuximab plus gemcitabine/oxaliplatin (GEMOXCET) in first-line metastatic pancreatic cancer: a multicentre phase II study

Targeting the epidermal growth factor receptor pathway in pancreatic cancer seems to be an attractive therapeutic approach. This study assessed the efficacy of cetuximab plus the combination of gemcitabine/oxaliplatin in metastatic pancreatic cancer. Eligible subjects had histological or cytological diagnosis of metastatic pancreatic adenocarcinoma. The primary end point was response according to RECIST. Patients received cetuximab 400 mg m⁻² at first infusion followed by weekly 250 mg m⁻² combined with gemcitabine 1000 mg m⁻² as a 100 min infusion on day 1 and oxaliplatin 100 mg m⁻² as a 2-h infusion on day 2 every 2 weeks. Between January 2005 and August 2006, a total of 64 patients (22 women (34%), 42 men (66%); median age 64 years (range 31–78)) were enrolled at seven study centres. On October 2007, a total of 17 patients were alive. Sixty-two patients were evaluable for baseline and 61 for assessment of response to treatment in an intention-to-treat analysis. Six patients had an incomplete drug combination within the first cycle of the treatment plan (n=4 hypersensitivity reactions to the first cetuximab infusion, n=2 refused to continue therapy). Reported grade 3/4 toxicities (% of patients) were leukopaenia 15%, anaemia 8%, thrombocytopaenia 10%, diarrhoea 7%, nausea 18%, infection 18% and allergy 7%. Cetuximab-attributable skin reactions occurred as follows: grade 0: 20%, grade 1: 41%, grade 2: 30% and grade 3: 10%. The intention-to-treat analysis of 61 evaluable patients showed an overall response rate of 33%, including 1 (2%) complete and 19 (31%) partial remissions. There were 31% patients with stable and 36% with progressive disease or discontinuation of the therapy before re-staging. The presence of a grade 2 or higher skin rash was associated with a higher likelihood of achieving objective response. Median time to progression was 118 days, with a median overall survival of 213 days. A clinical benefit response was noted in 24 of the evaluable 61 patients (39%). The addition of cetuximab to the combination of gemcitabine and oxaliplatin is well tolerated but does not increase response or survival in patients with metastatic pancreatic cancer.

Epiphytic bacteria on the Antarctic ice diatom Amphiprora kufferathii Manguin cleave hydrogen peroxide produced during algal photosynthesis

The Antarctic ice diatom Amphiprora kufferathii Manguin is always accompanied by epiphytic bacteria in its natural habitat. To investigate the nature of this relationship, axenic cultures of A. kufferathii were obtained by ampicillin treatment. Diatom cultures without bacteria were less dense. The bacteria were shown to consume hydrogen peroxide produced by the diatom during photosysnthesis and algal photosynthesis after a hydrogen peroxide shock recovered faster in the presence of bacteria. Three proteobacterial strains isolated from a culture of A. kufferathii were phylogenetically affiliated with the alphaproteobacterial genus Sulfitobacter, the gammaproteobacterial genus Colwellia, and the genus Pibocella of the Bacteriodetes. Native protein gel electrophoresis and enzyme activity staining revealed the presence of superoxide dismutase and glutathione reductase in the isolated bacteria and in A. kufferathii cultures. Catalase was detected in bacterial extracts but not in axenic cultures of A. kufferathii. These observations indicate that the epiphytic bacteria make a significant contribution to the diatom's antioxidative defences. The relationship between the bacteria and A. kufferathii seems to be beneficial for both partners and enhances growth of Amphiprora in the sea ice.

Probiotic lactobacilli and VSL#3 induce enterocyte beta-defensin 2

Recent evidence suggests that probiotic bacteria may stabilize gut barrier function via induction of anti-microbial peptides such as defensins. This study aimed to elucidate the induction mechanism of the human beta defensin-2 (hBD-2) gene by different probiotic lactobacillus strains. The expression of hBD-2 mRNA peaked at 6 h of incubation upon treatment of Caco-2 cells and increased with higher dosage of various probiotic bacteria. Deletion of nuclear factor (NF)-kappaB and activator protein-1 (AP-1) binding sites on the hBD-2 promoter resulted in a complete abrogation of promoter activation by probiotics. As revealed by the use of specific mitogen-activated protein kinase (MAPK) inhibitors the hBD-2 induction was dependent on the MAPK extracellular regulated kinase (ERK 1/2), p38 and c-Jun N-terminal kinase (JNK), although to varying degrees. Several Lactobacillus strains and VSL#3, a probiotic cocktail of four lactobacilli, three bifidum and one streptococcus species, induced the secretion of the hBD-2 peptide into the culture media as shown by enzyme-linked immunosorbent assay (ELISA). Thus, the present study suggests that lactobacilli and the VSL#3 bacterial mixture strengthen intestinal barrier functions through the up-regulation of hBD-2 via induction of proinflammatory pathways including NF-kappaB and AP-1 as well as MAPKs.

Outpatient chemotherapy with gemcitabine and oxaliplatin in patients with biliary tract cancer

This phase II study was conducted to determine the efficacy and toxicity of a gemcitabine (GEM) and oxaliplatin (OX) chemotherapy protocol in patients with unresectable biliary tract cancer (BTC). Patients were treated with GEM 1000 mg m⁻² (30 min infusion) on days 1, 8, 15, and OX 100 mg m⁻² (2 h infusion) on days 1 and 15 (gemcitabine and oxaliplatin (GEMOX-3 protocol), repeated every 28 days. The data were collected according to the Simon 2-stage design for a single centre phase II study (α=0.05; β=0.2). Primary end point was response rate; secondary end points were time-to-progression (TTP), median survival, and safety profile. Thirty-one patients were enrolled in the study between July 2002 and April 2005. Therapeutic responses were as follows: partial response in eight patients (26%, 95% confidence interval (CI) 14–44), stable disease in 14 patients (45%, 95%CI 29–62), resulting in a disease control rate of 71%. Nine patients (29%, 95%CI 16–47) had progressive disease. Median TTP was 6.5 months. Median overall survival was 11 months. Common Toxicity Criteria (CTC) Grade 3–4 toxicities were transient thrombocytopenia (23%), peripheral sensory neuropathy (19%), leucopenia (16%), and anaemia (10%). In conclusion the GEMOX-3 protocol is active and well tolerated in patients with advanced BTC. It can be applied in an outpatient setting with three visits per month only.

[Gastric cancer--risk factors and medical therapy]

Gastric cancer is the fourth common cancer worldwide and the second leading cause of cancer related deaths. Although the incidence of gastric cancer is declining, gastric cancer will remain a serious medical problem due to its high mortality rates. In contrast, cancer of the gastroesophageal junction is the most increasing neoplasm in the western world. Unfortunately, the vast majority of gastric cancer is diagnosed at an advanced stage, associated with a poor prognosis where the therapeutic options are limited. Over the past 15 years advances have been made in the knowledge of risk factors as well as the pathogenesis of gastric cancer. As the most important exogenous risk factor Helicobacter pylori was categorized as a class I carcinogen by the WHO. Additionally, genetic changes associated with the risk of gastric cancer have been defined. Progress, although slow, has also been made in the non-surgical therapy of gastric cancer due to multimodal therapeutic strategies. All these advances could lead to a better identification of patients being at risk of developing gastric cancer. Furthermore, new neoadjuvant and adjuvant therapy regimes as well as targeted therapeutic approaches in the future could lead to a better prognosis of gastric cancer.

Outpatient chemotherapy with gemcitabine and oxaliplatin in advanced biliary tract cancer; a phase II study

14006

Background: Biliary tract cancer is a heterogeneous tumor entity with a poor prognosis if unresectable. There is a need for an effective, safe and patient friendly treatment. Methods: Patients with typical histology for cholangiocarcinoma, adequate haematological, renal and liver function, measurable tumor formation, life expectancy for more than 3 months, and written informed consent were treated with Gemcitabine 1000mg/m2 (30 min infusion) day 1, 8, 15 and Oxaliplatin 100mg/m2 (2 h infusion) day 1 and 15. Chemotherapy cycles were repeated every 28 days (GEMOX-3 protocol). The data were collected according to the Simon 2-step design for a single centre phase II study (α=0.05; β=0.2). Planned sample size 29. Primary endpoint was the response rate; secondary endpoints were time to progression, median survival and safety profile. Results: Thirty-one consecutive patients were enrolled between July 2002 and April 2005. The efficacy was as follows: partial response 8 pts (26%), stable disease 14 pts (45%). Thus, the disease control rate was 71%, while 9 pts (29%) had progressive disease. Median time to progression was 6.5 months. Median overall survival after start of treatment was 10.4 months, after initial diagnosis it was 15.6 months. National Cancer Institute Common Toxicity Criteria grade 3–4 toxicities were transient thrombocytopenia in 23% of patients, peripheral sensory neuropathy 19%, leukopenia 16% and anaemia 10%. Conclusion: The GEMOX-3 protocol is active and well tolerated in patients with advanced biliary tract cancer. It can be applied in an outpatient setting with three treatments per month only. The positive results of this and other phase II trials underscore the importance of a large controlled clinical trial to verify the data.

No significant financial relationships to disclose.

Antimicrobial skin peptides and proteins

Human skin is permanently exposed to microorganisms, but rarely infected. One reason for this natural resistance might be the existence of a 'chemical barrier' consisting in constitutively and inducibly produced antimicrobial peptides and proteins (AMPs). Many of these AMPs can be induced in vitro by proinflammatory cytokines or bacteria. Apart from being expressed in vivo in inflammatory lesions, some AMPs are also focally expressed in skin in the absence of inflammation. This suggests that non-inflammatory stimuli of endogenous and/or exogenous origin can also stimulate AMP synthesis without inflammation. Such mediators might be ideal 'immune stimulants' to induce only the innate antimicrobial skin effector molecules without causing inflammation.

[Seizures following Billroth II gastrectomy]

HISTORY

A 64-year old somnolent man was admitted to the emergency department with a reported seizure half an hour earlier. Due to similar episodes the patient had been treated with antiepileptics in the past. The patient s past history revealed a partial gastrectomy (Billroth II) more than ten years ago.

DIAGNOSTIC FINDINGS AND THERAPY

At the time of admission blood glucose was 31 mg/dl. Other routine laboratory analyses and the clinical examination were normal. In addition, a detailed neurological examination and a cranial CT-scan were normal. Due to the hypoglycemia a dumping syndrome was suspected. A three hour oral glucose tolerance test (OGTT) resulted in a late hypoglycemia, establishing the diagnosis of late dumping. After adaptation of the patient's diet no further hypoglycemic episodes occurred.

CONCLUSION

Manifestation of a dumping syndrome may occur even years after gastrectomy. Therefore, in patients presenting with hypoglycemia and a history of gut surgery, a dumping syndrome should be suspected. Furthermore, seizures due to hypoglycemia may be the only manifestation of late dumping.

[Esophageal carcinoma: non-surgical therapy]

Esophageal carcinoma is one of the most common cancers in the world. There is a rising incidence of adenocarcinoma of the esophagus in Western countries. The present standard of care of patients with early tumors (Tis-T1 N0-N1 M0) is surgery and there is no role for chemo- or radiotherapy. Surgical treatment of stage II patients with locally resectable tumors is associated with poor survival figures due to an increase of regional and distant lymph node metastases. Adjuvant chemotherapy should be used only in the setting of clinical trials. The role of neoadjuvant chemo-radiotherapy in patients with resectable tumors is controversial. There is also evidence that some patients with a complete response after chemo-radiotherapy do not have a further benefit from surgical treatment. Therefore, the appropriate application of these varied therapeutic interventions should be performed at specialized centers. The role of chemotherapy and radiation is now established in locally advanced inoperable disease. How best to deliver these modes of therapy has yet to be defined. Prospective randomised trials are the only way to define the best therapeutic strategies for the different subgroups of patients with esophageal carcinoma. Progress with newer chemotherapy agents, optimal radiotherapy protocols and innovations are likely to improve responses to combination treatments, but may more importantly limit associated toxicity. Future trials should also assess quality of life indices as end points, that are of particular importance in populations with a median survival of approx, one year. Patients with stage IVb esophageal carcinoma have a life expectancy of less than six months and palliative teatment strategies should primarily aim at the improvement of tumor related symptoms and the maintenance of nutrition.

NOD2 (CARD15) mutations in Crohn's disease are associated with diminished mucosal alpha-defensin expression

BACKGROUND

Mutations in NOD2, a putative intracellular receptor for bacterial peptidoglycans, are associated with a subset of Crohn's disease but the molecular mechanism linking this protein with the disease pathogenesis remains unclear. Human alpha defensins (HD-5 and HD-6) are antibiotic effector molecules predominantly expressed in Paneth cells of the ileum. Paneth cells also express NOD2. To address the hypothesis that the function of NOD2 may affect expression of Paneth cell defensins, we compared their expression levels with respect to NOD2 mutations in Crohn's disease.

METHODS

Forty five Crohn's disease patients (24 with NOD2 mutations, 21 with wild-type NOD2) and 12 controls were studied. Real time reverse transcription-polymerase chain reaction was performed with mucosal mRNA for HD-5, HD-6, lysozyme, secretory phospholipase A2 (sPLA2), tumour necrosis factor alpha, interleukin 8, and human hypoxanthine phosphoribosyltransferase (housekeeping gene). Immunohistochemistry with anti-HD-5 and histological Paneth cell staining were performed in 10 patients with NOD2 mutations or wild-type genotypes.

RESULTS

Ileal expression of HD-5 and HD-6, but not sPLA2 or lysozyme, were diminished in affected ileum, and the decrease was significantly more pronounced in patients with NOD2 mutations. In the colon, HD-5, HD-6, and sPLA2 were increased during inflammation in wild-type but not in NOD2 mutated patients. In both the colon and ileum, proinflammatory cytokines and lysozyme were unaffected by NOD2 status. Immunohistochemistry identified Paneth cells as the sole source of HD-5.

CONCLUSION

As alpha defensins are important in the mucosal antibacterial barrier, their diminished expression may explain, in part, the bacterial induced mucosal inflammation and ileal involvement of Crohn's disease, especially in the case of NOD2 mutations.

Hepatitis C virus infection in intravenous drug users

Intravenous drug use (IVDU) remains a major means of hepatitis C virus (HCV) transmission. In this study, 101 drug users were studied prospectively after cessation of IVDU. Of these, 75.8% were anti-HCV positive, and 71.4% had elevated levels of alanine aminotransferase. These levels decreased significantly within 1 month of IVDU cessation (p 0.02). Liver biopsies showed minimal or mild fibrosis in 32 (71%) of 45 subjects, and severe fibrosis in two (4.4%) subjects. Anti-HCV-positive intravenous drug users in this study presented with mild liver disease and variable stages of disease progression. Biochemical disease activity might be affected by IVDU.

[Cholangiocarcinoma]

Cholangiocarcinomas (CCC) are rare tumors with an incidence of 2-4/100,000 per year. They are a heterogeneous group of neoplasias that include the most common perihilar or Klatskin tumor (60%), the intrahepatic (peripheral) CCC, the extrahepatic bile duct cancer, the gallbladder cancer and the cancer of the ampulla of Vater. At the time of diagnosis only 20% of patients can be treated by surgery, that offers the only chance for cure. Due to high recurrence rates liver transplantation is not indicated. Patients with advanced unresectable carcinoma have a dismal prognosis with an overall survival rate of only 6-8 months. Neither chemotherapy nor radiation therapy improves survival. In patients not eligible for curative surgery prevention or treatment of cholestatis is the main objective. This can be achieved endoscopically, percutaneously or by surgical biliodigestive anastomosis. Palliative chemotherapy results in response rates up to 20%. The most frequently used agents are 5-FU and Gemcitabine that can be combined with external or internal radiation. By combining different treatment modalities significant survival can be achieved in some patients. Evidence Based Medicine studies are needed before treatment strategies can be recommended for clinical practice.

Reconstruction of laser-scanned 3D torso topography and stereoradiographical spine and rib-cage geometry in scoliosis

Assessments of scoliosis are routinely done by means of clinical examination and full spinal x-rays. Multiple exposure to ionization radiation, however, can be hazardous to the child and is costly. Here, we explain the use of a noninvasive imaging technique, based on laser optical scanning, for quantifying the three-dimensional (3D) trunk surface topography that can be used to estimate parameters of 3D deformity of the spine. The laser optical scanning system consisted of four BIRIS laser cameras mounted on a ring moving along a vertical axis, producing a topographical mapping of the entire torso. In conjunction with the laser scans, an accurate 3D reconstruction of the spine and rib cage were developed from the digitized x-ray images. Results from 14 scoliotic patients are reported. The digitized surfaces provided the foundation data to start studying concordance of trunk surface asymmetry and spinal shape in idiopathic scoliosis.

Estimation of spinal deformity in scoliosis from torso surface cross sections

STUDY DESIGN

Correlation of torso scan and three-dimensional radiographic data in 65 scans of 40 subjects.

OBJECTIVES

To assess whether full-torso surface laser scan images can be effectively used to estimate spinal deformity with the aid of an artificial neural network.

SUMMARY OF BACKGROUND DATA

Quantification of torso surface asymmetry may aid diagnosis and monitoring of scoliosis and thereby minimize the use of radiographs. Artificial neural networks are computing tools designed to relate input and output data when the form of the relation is unknown.

METHODS

A three-dimensional torso scan taken concurrently with a pair of radiographs was used to generate an integrated three-dimensional model of the spine and torso surface. Sixty-five scan-radiograph pairs were generated during 18 months in 40 patients (Cobb angles 0-58 degrees ): 34 patients with adolescent idiopathic scoliosis and six with juvenile scoliosis. Sixteen (25%) were randomly selected for testing and the remainder (n = 49) used to train the artificial neural network. Contours were cut through the torso model at each vertebral level, and the line joining the centroids of area of the torso contours was generated. Lateral deviations and angles of curvature of this line, and the relative rotations of the principal axes of each contour were computed. Artificial neural network estimations of maximal computer Cobb angle were made.

RESULTS

Torso-spine correlations were generally weak (r < 0.5), although the range of torso rotation related moderately well to the maximal Cobb angle (r = 0.64). Deformity of the torso centroid line was minimal despite significant spinal deformity in the patients studied. Despite these limitations and the small data set, the artificial neural network estimated the maximal Cobb angle within 6 degrees in 63% of the test data set and was able to distinguish a Cobb angle greater than 30 degrees with a sensitivity of 1.0 and specificity of 0.75.

CONCLUSIONS

Neural-network analysis of full-torso scan imaging shows promise to accurately estimate scoliotic spinal deformity in a variety of patients.