Sub-Bandgap Sensitization of Perovskite Semiconductors via Colloidal Quantum Dots Incorporation

By taking advantage of the outstanding intrinsic optoelectronic properties of perovskite-based photovoltaic materials, together with the strong near-infrared (NIR) absorption and electronic confinement in PbS quantum dots (QDs), sub-bandgap photocurrent generation is possible, opening the way for solar cell efficiencies surpassing the classical limits. The present study shows an effective methodology for the inclusion of high densities of colloidal PbS QDs in a MAPbI3 (methylammonium lead iodide) perovskite matrix as a means to enhance the spectral window of photon absorption of the perovskite host film and allow photocurrent production below its bandgap. The QDs were introduced in the perovskite matrix in different sizes and concentrations to study the formation of quantum-confined levels within the host bandgap and the potential formation of a delocalized intermediate mini-band (IB). Pronounced sub-bandgap (in NIR) absorption was optically confirmed with the introduction of QDs in the perovskite. The consequent photocurrent generation was demonstrated via photoconductivity measurements, which indicated IB establishment in the films. Despite verifying the reduced crystallinity of the MAPbI3 matrix with a higher concentration and size of the embedded QDs, the nanostructured films showed pronounced enhancement (above 10-fold) in NIR absorption and consequent photocurrent generation at photon energies below the perovskite bandgap.

Light management with quantum nanostructured dots-in-host semiconductors

Insightful knowledge on quantum nanostructured materials is paramount to engineer and exploit their vast gamut of applications. Here, a formalism based on the single-band effective mass equation was developed to determine the light absorption of colloidal quantum dots (CQDs) embedded in a wider bandgap semiconductor host, employing only three parameters (dots/host potential barrier, effective mass, and QD size). It was ascertained how to tune such parameters to design the energy level structure and consequent optical response. Our findings show that the CQD size has the biggest effect on the number and energy of the confined levels, while the potential barrier causes a linear shift of their values. While smaller QDs allow wider energetic separation between levels (as desired for most quantum-based technologies), the larger dots with higher number of levels are those that exhibit the strongest absorption. Nevertheless, it was unprecedently shown that such quantum-enabled absorption coefficients can reach the levels (10⁴-10⁵cm^-1) of bulk semiconductors.

Rituximab is an effective treatment in patients with pemphigus vulgaris and demonstrates a steroid-sparing effect

BACKGROUND

Corticosteroids (CS) with or without adjuvant immunosuppressant agents are standard treatment for pemphigus vulgaris (PV). The efficacy of adjuvant therapies in minimizing steroid-related adverse events (AEs) is unproven.

OBJECTIVES

To utilize data collected in a French investigator-initiated, phase III, open-label, randomized controlled trial to demonstrate the efficacy and safety of rituximab and seek approval for its use in PV.

METHODS

This was an independently conducted post hoc analysis of the moderate-to-severe PV subset enrolled in the Ritux 3 study. Patients were randomized to rituximab plus 0·5 or 1·0 mg kg-1 per day prednisone tapered over 3 or 6 months, or 1·0 or 1·5 mg kg-1 per day prednisone alone tapered over 12 or 18 months, respectively (according to disease severity). The primary end point was complete remission at month 24 without CS (CRoff) for ≥ 2 months, and 24-month efficacy and safety results were also reported.

RESULTS

At month 24, 34 of 38 patients (90%) on rituximab plus prednisone achieved CRoff ≥ 2 months vs. 10 of 36 patients (28%) on prednisone alone. Median total cumulative prednisone dose was 5800 mg in the rituximab plus prednisone arm vs. 20 520 mg for prednisone alone. Eight of 36 patients (22%) who received prednisone alone withdrew from treatment owing to AEs; one rituximab-plus-prednisone patient withdrew due to pregnancy. Overall, 24 of 36 patients (67%) on prednisone alone experienced a grade 3/4 CS-related AE vs. 13 of 38 patients (34%) on rituximab plus prednisone.

CONCLUSIONS

In patients with moderate-to-severe PV, rituximab plus short-term prednisone was more effective than prednisone alone. Patients treated with rituximab had less CS exposure and were less likely to experience severe or life-threatening CS-related AEs. What's already known about this topic? Pemphigus vulgaris (PV) is the most common type of pemphigus. Corticosteroids, a standard first-line treatment for PV, have significant side-effects. Although their effects are unproven, adjuvant corticosteroid-sparing agents are routinely used to minimize steroid exposure and corticosteroid-related side-effects. There is evidence that the anti-CD20 antibody rituximab is effective in the treatment of patients with severe recalcitrant pemphigus and in patients with newly diagnosed pemphigus. What does this study add? This study provides a more detailed analysis of patients with PV enrolled in an investigator-initiated trial. Rituximab plus prednisone had a steroid-sparing effect and more patients achieved complete remission off prednisone. Fewer patients experienced grade 3 or grade 4 steroid-related adverse events than those on prednisone alone. This collaboration between academia and industry, utilizing independent post hoc analyses, led to regulatory authority approvals of rituximab in moderate-to-severe PV.

Synthesis of a Pentaerythritol Derivative Bearing Azo Functions

A convenient strategy for synthesis of a pentaerythritol derivative diacetal containing azo functions is presented; NMR data are discussed and are in good agreement with the molecular structure.

Cigarette toxin 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) induces experimental pancreatitis through α7 nicotinic acetylcholine receptors (nAChRs) in mice

Clinical studies have shown that cigarette smoking is a dose-dependent and independent risk factor for acute pancreatitis. Cigarette smoke contains nicotine which can be converted to the potent receptor ligand and toxin, NNK [4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone]. Previously, we have shown that NNK induces premature activation of pancreatic zymogens in rats, an initiating event in pancreatitis, and this activation is prevented by pharmacologic inhibition of nicotinic acetylcholine receptors (nAChR). In this study, we determined whether NNK mediates pancreatitis through the α7 isoform of nAChR using α7nAChR knockout mice. PCR analysis confirmed expression of non-neuronal α7nAChR in C57BL/6 (WT) mouse and human acinar cells. NNK treatment stimulated trypsinogen activation in acini from WT but not α7nAChR-/- mice. NNK also stimulated trypsinogen activation in human acini. To further confirm these findings, WT and α7nAChR-/- mice were treated with NNK in vivo and markers of pancreatitis were measured. As observed in acini NNK treatment induced trypsinogen activation in WT but not α7nAChR-/- mice. NNK also induced other markers of pancreatitis including pancreatic edema, vacuolization and pyknotic nuclei in WT but not α7nAChR-/- animals. NNK treatment led to increased neutrophil infiltration, a marker of inflammation, in WT mice and to a significantly lesser extent in α7nAChR-/- mice. We also examined downstream targets of α7nAChR activation and found that calcium and PKC activation are involved down stream of NNK stimulation of α7nAChR. In this study we used genetic deletion of the α7nAChR to confirm our previous inhibitor studies that demonstrated NNK stimulates pancreatitis by activating this receptor. Lastly, we demonstrate that NNK can also stimulate zymogen activation in human acinar cells and thus may play a role in human disease.

Oesophageal involvement in 26 consecutive patients with mucous membrane pemphigoid

BACKGROUND

Oesophageal involvement of mucous membrane pemphigoid (MMP) has not yet been thoroughly described.

OBJECTIVES

To characterize systematically the endoscopic lesions of a series of patients with oesophageal symptoms seen at a referral centre for autoimmune bullous diseases.

METHODS

Clinical, endoscopic and immunological findings of consecutively referred patients with MMP with oesophageal involvement, systemic and endoscopic treatments, and follow-up are described.

RESULTS

Of 477 consecutive patients with MMP consulting between 2002 and 2012, 26 (5·4%) had symptomatic oesophageal involvement. Dysphagia, observed in 23 (88%) patients, was the most frequent symptom. Oesophageal symptoms could be the first sign of MMP. Patients with oesophageal involvement had a mean of three other involved sites. At initial oesophageal endoscopy, 17 of 26 patients had active lesions (intact bullae, erosions and/or erythema), 15 had stricture(s) and 12 had other cicatricial lesions. Systemic therapy alone achieved oesophageal symptom relief for five patients. Dilatation was combined with systemic therapy for 12 patients and was successful in nine; one perforation occurred.

CONCLUSIONS

Symptomatic oesophageal involvement affected 5·4% of patients with MMP. Dermatologists and gastroenterologists should be aware of these mucocutaneous diseases and their oesophageal involvement, as it could lead to earlier diagnosis and better care. Oesophageal dilatation could be a therapeutic option for symptomatic stricture not relieved by optimized systemic therapy alone.

Idiopathic linear IgA bullous dermatosis: prognostic factors based on a case series of 72 adults

BACKGROUND

Linear IgA bullous dermatosis (LABD) is a clinically and immunologically heterogeneous, subepidermal, autoimmune bullous disease (AIBD), for which the long-term evolution is poorly described.

OBJECTIVES

To investigate the clinical and immunological characteristics, follow-up and prognostic factors of adult idiopathic LABD.

METHODS

This retrospective study, conducted in our AIBD referral centre, included adults, diagnosed between 1995 and 2012, with idiopathic LABD, defined as pure or predominant IgA deposits by direct immunofluorescence. Clinical, histological and immunological findings were collected from charts. Standard histology was systematically reviewed, and indirect immunofluorescence (IIF) on salt-split skin (SSS) and immunoblots (IBs) on amniotic membrane extracts using anti-IgA secondary antibodies were performed, when biopsies and sera obtained at diagnosis were available. Prognostic factors for complete remission (CR) were identified using univariate and multivariate analyses.

RESULTS

Of the 72 patients included (median age 54 years), 60% had mucous membrane (MM) involvement. IgA IIF on SSS was positive for 21 of 35 patients tested; 15 had epidermal and dermal labellings. Immunoelectron microscopy performed on the biopsies of 31 patients labelled lamina lucida (LL) (26%), lamina densa (23%), anchoring-fibril zone (AFz) (19%) and LL+AFz (23%). Of the 34 IgA IBs, 22 were positive, mostly for LAD-1/LABD97 (44%) and full-length BP180 (33%). The median follow-up was 39 months. Overall, 24 patients (36%) achieved sustained CR, 19 (29%) relapsed and 35% had chronic disease. CR was significantly associated with age > 70 years or no MM involvement. No prognostic immunological factor was identified.

CONCLUSIONS

Patients with LABD who are < 70 years old and have MM involvement are at risk for chronic evolution.

Abstract P6-09-28: Prognostic impact of the inclusion of uPA/PAI-1 in ER+/Her2- pN0 early breast cancer adjuvant treatments decision-making

Purpose: Intermediate-risk early breast cancer (EBC) is a heterogeneous group in which adjuvant chemotherapy decision prove to be difficult. Clinical and pathological criteria might be insufficient to determine the best therapeutic options for patients, and validated biomarkers are urgently needed to help decision making, such as the LOE-I uPA/PAI-1 biomarker. The aim of this study is to evaluate the clinical outcome of a large, unselected, ER+/HER2- pN0 EBC cohort of patients in whom the routine clinical decision process included a prospective uPA/PAI-1 determination.

Methods: This monocentric retrospective study included 520 ER+/HER2- pN0/M0 EBC patients who had curative surgery in our center between 2006 and 2011. Adjuvant therapeutic strategy was decided based on clinico-pathological data, altogether with a routine prospective determination of uPA/PAI-1 tumor levels. We evaluated the correlation between uPA/PAI-1 levels, classical clinico-pathological variables and the patient's outcome (relapse free survival, RFS; overall survival, OS).

Results: Median age was 54 years (range 27-85). 75% of tumors were classified T1, 25% T2 and above. We found 80.8% of ductal carcinomas, 12.3% of lobular carcinomas and 6.9% of other histological types. SBR grade 1-2 represented 82.5% of our cohort versus 17.5% of grade 3. Mitotic count was &lt;10 in 63.5% of cases, and ≥10 in 36.5%. Peri-tumoral invasion (PVI) was seen in 17% of tumors. Progesterone receptors (PR) were positive in 79.6% of cases. Median follow-up was 5.4 years. 5 and 10 years RFS were respectively 95% and 89% (n=33 local or metastatic relapse). 5 year OS was 96.3%. We found 40% of low uPA/PAI-1 levels, and 60% of high uPA and/or PAI-1 levels. By using uPA/PAI-1 levels in our adjuvant treatment decision-making, 75% of patients with low uPA/PAI-1 levels did not received chemotherapy and 60% of patients with high uPA and/or PAI-1 levels received chemotherapy. 98.3% of our patients received endocrine therapy as adjuvant treatment for at least 5 years. No statistical significant correlation was found between uPA/PAI-1 levels and RFS (p=0.3) or OS (p=0.28). In univariate analysis, tumor size (p=0.048; p=0.0694), histological grade (p=0.007; p=0.0142), PR status (p=0.001; p=0.0002) and mitotic count (p=0.0001; p=0.0001) were statistically correlated with RFS and OS, respectively. Using cox regression model, PR status (p&lt;0.003) and mitotic count (p&lt;0.001) appeared to be strongly correlated with RFS. No changes in significant variables were seen when the analyses were restricted to the grade 2 subgroup (n=339).

Conclusion: The individualization of patients' treatment using uPA/PAI-1 tumor levels allows the reversion of the well-known poor prognostic impact of high uPA/PAI-1 levels and strongly support the use of this LOE-I biomarker in clinical practice. PR status and mitotic activity remains independent major prognostic factors in optimally treated patients. The evaluation of the additional impact of multigene signature in this setting needs to be performed. Longer 10-years follow-up needs to be done in this ER+/HER2- subgroup, particularly to evaluate the risk of late relapse after endocrine therapy.

Citation Format: Viala M, Alexandre M, Thézenas S, Lamy P-J, Bibeau F, Gutowski M, Colombo P-E, Romieu G, Jacot W, Guiu S. Prognostic impact of the inclusion of uPA/PAI-1 in ER+/Her2- pN0 early breast cancer adjuvant treatments decision-making [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P6-09-28.