Electrical modulation of the complex refractive index in mid-infrared quantum cascade lasers

We have demonstrated an integrated three terminal device for the modulation of the complex refractive index of a distributed feedback quantum cascade laser (QCL). The device comprises an active region to produce optical gain vertically stacked with a control region made of asymmetric coupled quantum wells (ACQW). The optical mode, centered on the gain region, has a small overlap also with the control region. Owing to the three terminals an electrical bias can be applied independently on both regions: on the laser for producing optical gain and on the ACQW for tuning the energy of the intersubband transition. This allows the control of the optical losses at the laser frequency as the absorption peak associated to the intersubband transition can be electrically brought in and out the laser transition. By using this function a laser modulation depth of about 400 mW can be achieved by injecting less than 1 mW in the control region. This is four orders of magnitude less than the electrical power needed using direct current modulation and set the basis for the realisation of electrical to optical transducers.

Familial adenomatous polyposis: clinical presentation, detection and surveillance

Colorectal cancer (CRC) is a leading cause of cancer related death in the western countries. It remains an important health problem, often under-diagnosed. The symptoms can appear very late and about 25% of the patients are diagnosed at metastatic stage. Familial adenomatous polyposis (FAP) is an inherited colorectal cancer syndrome, characterized by the early onset of hundred to thousands of adenomatous polyps in the colon and rectum. Left untreated, there is a nearly 100% cumulative risk of progression to CRC by the age of 35-40 years, as well as an increased risk of various other malignancies. CRC can be prevented by the identification of the high risk population and by the timely implementation of rigid screening programs which will lead to special medico-surgical interventions.

Quality of care indicators in rectal cancer

Quality of health care is a hot topic, especially with regard to cancer. Although rectal cancer is, in many aspects, a model oncologic entity, there seem to be substantial differences in quality of care between countries, hospitals and physicians. PROCARE, a Belgian multidisciplinary national project to improve outcome in all patients with rectum cancer, identified a set of quality of care indicators covering all aspects of the management of rectal cancer. This set should permit national and international benchmarking, i.e. comparing results from individual hospitals or teams with national and international performances with feedback to participating teams. Such comparison could indicate whether further improvement is possible and/or warranted.

Systematic resequencing of X-chromosome synaptic genes in autism spectrum disorder and schizophrenia

Autism spectrum disorder (ASD) and schizophrenia (SCZ) are two common neurodevelopmental syndromes that result from the combined effects of environmental and genetic factors. We set out to test the hypothesis that rare variants in many different genes, including de novo variants, could predispose to these conditions in a fraction of cases. In addition, for both disorders, males are either more significantly or more severely affected than females, which may be explained in part by X-linked genetic factors. Therefore, we directly sequenced 111 X-linked synaptic genes in individuals with ASD (n = 142; 122 males and 20 females) or SCZ (n = 143; 95 males and 48 females). We identified >200 non-synonymous variants, with an excess of rare damaging variants, which suggest the presence of disease-causing mutations. Truncating mutations in genes encoding the calcium-related protein IL1RAPL1 (already described in Piton et al. Hum Mol Genet 2008) and the monoamine degradation enzyme monoamine oxidase B were found in ASD and SCZ, respectively. Moreover, several promising non-synonymous rare variants were identified in genes encoding proteins involved in regulation of neurite outgrowth and other various synaptic functions (MECP2, TM4SF2/TSPAN7, PPP1R3F, PSMD10, MCF2, SLITRK2, GPRASP2, and OPHN1).

ICP27 protein of Marek's disease virus interacts with SR proteins and inhibits the splicing of cellular telomerase chTERT and viral vIL8 transcripts

All herpesviruses have a post-transcriptional regulatory protein that prevents precursor mRNA splicing and leads to the shutting off of host protein synthesis. The ICP27 protein of herpes simplex virus 1 (HSV-1) is the prototype of these proteins. Marek's disease virus (MDV-1), an alphaherpesvirus that induces lymphoma in birds, also has an ICP27 protein that is produced in lytic MDV-1-infected cells. We characterized this protein. We demonstrated ICP27 production in latently infected MSB-1 cells, but only on MDV-1 reactivation. ICP27 was found predominantly in specific structures within the nucleus. The ICP27 of MDV-1 colocalized and interacted with SR proteins. We demonstrated inhibitory effects of MDV-1 ICP27 on the splicing of both the viral vIL8 and cellular chTERT (telomerase reverse transcriptase) genes. Thus, the ICP27 of MDV-1 plays a similar role to the ICP27 of HSV-1 and may be involved in MDV-1 replication and the development of Marek's disease.

Combination of gemcitabine and cetuximab in patients with advanced cholangiocarcinoma: A phase II study of the Belgian Group of Digestive Oncology

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Background: Cholangiocarcinomas (CCK) are uncommon tumors with an increasing incidence and a poor prognosis. Epidermal growth factor receptor (EGFR) expression and activation in CCK have been demonstrated.

Methods: We conducted a multicenter phase II trial combining cetuximab (Ctx), an anti-EGFR chimerized IgG1 monoclonal antibody, to gemcitabine (Gem). Patients with either locally advanced (LA) or metastatic (M) CCK (excluding gallbladder) were included; no prior systemic therapy was allowed. Ctx was administrated at the initial dose of 400 mg/m2 and further injections at 250 mg/m2 every 7 days, and Gem was administrated at 1000 mg/m2 on days 1, 8, and 15 every 4 weeks. The primary endpoint was the progression-free survival (PFS) rate at 6 months. A Simon 2-stage design was used. We hypothesized that Gem/Ctx would improve 6 month-PFS rate from 20% to 40%. We needed 3 patients with PFS ≥ 6 months from the first 13 to further include a total of 43 patients.

Results: Forty-four patients with advanced CCK (41% LA/59%M) were enrolled from 09/2008 to 01/2010. Median age was 61.5 years (range 40-86) and baseline ECOG PS was 0 for 68% and 1 for 32% of the patients. Forty-three percent of the patients had prior surgery. Forty-six percent of the patients were free from progression at 6 months. Median PFS was 5.8 months (95% CI, 4.4-7.4 m) and median overall survival was 11.6 months (95% CI, 8.7-14.6 m). Nine patients (20.9%) had partial response with a median duration of 5 months (range 2-10 m). Disease control rate (PR + SD > 8 weeks) was 81.4%. The most common grades 3/4 related-toxicities were haematological abnormalities (47.7%), skin rash (13.6%) and fatigue (11.3%). Due to toxicity, 6 patients discontinued study treatment; 14 and 3 patients had a Gem and Ctx dose reduction respectively. Among the nine responders, 8 experienced a skin rash of at least grade 2, suggesting a relationship between skin toxicity and efficacy.

Conclusions: Our study met its endpoint, i.e., a PFS rate of 46% at 6 months, suggesting that Gem-Ctx combination had promising activity with a manageable toxicity profile in advanced CCK. Adding Ctx to the new standard of care Gem-cisplatin deserves further investigations in CCK.

[Table: see text]