Near-infrared-light-based nano-platform boosts endosomal escape and controls gene knockdown in vivo

Current nanoparticle-based gene delivery techniques face two major limitations, namely, endosomal degradation and poor cytosolic release of the nanoparticles and nonspecificity of treatment. These limitations can be overcome with certain light-based techniques, such as photochemical internalization to enable endosomal escape of the delivered nanoparticles and light-controlled gene expression to overcome the nonspecific effects. However, these techniques require UV/visible light, which is either phototoxic and/or has low tissue penetration capabilities, thus preventing their use in deep tissues in a clinical setting. In an effort to overcome these barriers, we have successfully demonstrated a light-based gene delivery system that significantly boosts cytosolic gene delivery, with precise control over gene expression and the potential for use in nonsuperficial tissues. Core-shell fluorescent upconversion nanoparticles excited by highly penetrating near-infrared radiation and emitting simultaneously in the ultraviolet and visible ranges were synthesized and used as remote nanotransducers to simultaneously activate endosomal escape and gene knockdown. Gene knockdown using photomorpholinos was enhanced as much as 30% in vitro compared to the control without endosomal escape facilitation. A similar trend was seen in vivo in a murine melanoma model, demonstrating the enormous clinical potential of this system.

Presence or absence of intestinal metaplasia but not its burden is associated with prevalent high-grade dysplasia and cancer in Barrett's esophagus

Universal agreement on the inclusion of intestinal metaplasia to diagnose Barrett's esophagus (BE) is lacking. Our aim was to determine the association of intestinal metaplasia and its density with the prevalence of dysplasia/cancer in columnar lined esophagus (CLE). Patients with CLE but no intestinal metaplasia (CLE-no IM) were identified by querying the clinical pathology database using SNOMED codes for distal esophageal biopsies. CLE-IM patients were identified from a prospectively maintained database of BE patients. Subsequently, relative risks for prevalent dysplasia and cancer were calculated. Since patients with CLE-no IM are not usually enrolled in surveillance, only prevalent dysplasia/cancer on index endoscopy was analyzed. Goblet cell density and percent intestinal metaplasia were estimated. All biopsy slides were reviewed for dysplasia by two experienced gastrointestinal pathologists. Two hundred sixty-two CLE-IM and 260 CLE-no IM patients were included (age 64±12 vs. 60±11 years, P=0.001; whites 92% vs. 82%, P=0.001; males 99.7% vs. 99.3%, P=NS; CLE length 3.4±3.2 vears 1.4±0.4 cm, P=0.001 and hiatus hernia 64% vs. 56%, P=0.013). The odds of finding low-grade dysplasia and of high-grade dysplasia (HGD)/cancer were 12.5-fold (2.9-53.8, P=0.007) and 4.2-fold (95% CI 1.4-13, P=0.01) higher, respectively, in the CLE-IM group. Reanalysis after controlling for important variables of age, race, and length did not significantly alter the overall results. In CLE-IM group, when patients with high (>50/LPF) versus low goblet cell density (<50/LPF) and <10% versus >10% intestinal metaplasia were compared, the odds of HGD/cancer, OR 1.5 (0.5-4.9, P=0.5) and 1.97 (0.54-7.22), respectively, were not significantly higher. Demonstration of intestinal metaplasia continues to be an essential element in the definition of BE, but its quantification may not be useful for risk stratification of HGD/cancer in BE.

Evaluation of the updated confocal laser endomicroscopy criteria for Barrett's esophagus among gastrointestinal pathologists

Previously developed novel probe-based confocal laser endomicroscopy (pCLE) criteria have been found to have high accuracy and substantial interobserver agreement (IOA) for diagnosing dysplasia in Barrett's esophagus (BE) when used by endoscopists. These updated criteria are: (i) epithelial surface: saw toothed, (ii) cells: enlarged, (iii) cells: pleomorphic, (iv) glands: not equidistant, (v) glands: unequal in size and shape, and (vi) goblet cells: not easily identified. The accuracy and IOA among pathologists in the diagnosis of dysplasia using the novel pCLE criteria is not known. The primary objective of the study was to evaluate the accuracy, overall IOA and learning curve among three gastrointestinal (GI) pathologists in diagnosing dysplasia in BE using the updated pCLE criteria. The secondary aim was to compare the accuracy and IOA between GI pathologists and gastroenterology endoscopists. Ninety pCLE videos and respective histology were retrieved from a previously conducted multicenter, prospective, randomized, controlled trial evaluating the utility of pCLE in BE patients. Videos were obtained from 101 BE patients previously enrolled for surveillance or endoscopic treatment of high-grade dysplasia or early esophageal adenocarcinoma. Three GI pathologists reviewed 90 pCLE video clips for dysplasia versus no dysplasia, confidence in their diagnosis, and image quality. The overall accuracy for the diagnosis of dysplasia (low-grade dysplasia/high-grade dysplasia/esophageal adenocarcinoma) was 77.8% (95% confidence interval [CI]: 72.4-82.3). The accuracy was higher when pathologists had 'high confidence' in their assessment of the videos (93.8% vs. 69.3%, P < 0.001). There was no significant difference in accuracy between the first set of 30 and second set of 60 videos (84% vs. 74%, P = 0.065). IOA among GI pathologists was substantial, k = 0.65 (95% CI: 0.53-0.73). The sensitivity for detecting dysplasia was 85% (95% CI: 78.1-90.7) and the specificity was 70% (95% CI: 61.91-77.92). These results were comparable with the evaluation of the same set of videos by endoscopists. GI pathologists have high accuracy and substantial IOA for diagnosing BE dysplasia with pCLE. Pathologists appear to have similar accuracy and IOA as endoscopists. These results provide further support of endoscopists accurately interpreting the in vivo optical histology provided by pCLE.

Comparative assessment of platelet GpIIb/IIIa receptor occupancy ratio with Eptifibatide/Tirofiban in patients presenting with ACS and undergoing PCI

BACKGROUND

The level of platelet inhibition by a Glycoprotein IIb/IIIa (GpIIb/IIIa) antagonist therapy necessary to minimize thrombotic complications in patients undergoing percutaneous coronary intervention (PCI) is a subject of debate. The degree of platelet inhibition obtained 10 min after start of GpIIb/IIIa antagonist therapy predicts adverse events after PCI. The aim of this study was to look at platelet inhibition and to compare platelet GpIIb/IIIa receptors occupancy ratio (GpRO) with Eptifibatide and Tirofiban using various dose regimens and correlate with 30-day clinical outcomes in patients presenting with high-risk acute coronary syndromes (ACS) and undergoing PCI.

METHODS

The patients were divided into four sub groups: (1) Eptifibatide two intracoronary bolus (180 μg/kg) alone (E(B)); or (2) two intravenous bolus (180 μg/kg) followed by infusion at 2 μg/kg/min for 24 h (E(B + Inf)); and (3) Tirofiban standard bolus dose (0.4 μg/kg) over 30 min followed by infusion at 0.1 μg/kg/min (T(Std)); or (4) at ADVANCE dose bolus (25 μg/kg) over 3 min, followed by infusion at 0.1 μg/kg/min (T(Adv)). Number of GpIIb/IIIa receptors was assessed by flow cytometry at baseline and 10 min after the bolus and percentage of free receptors was determined to calculate the GpRO. Patients were followed for 30 days for any major adverse cardiac events (MACE).

RESULTS

200 consecutive patients (including 74% with ST-elevation ACS) were enrolled. GpRO in groups E(B) (n = 48) and E(B + Inf) (n = 44) were 62.7% ± 27.2% and 61.4% ± 6.1% respectively while in the groups T(Std) (n = 96) and T(Adv) (n = 12) groups were 35.1% ± 17.74% and 68.8% ± 27.3% respectively. The GpRO was similar in E(B), E(B + Inf) and T(Adv) groups and was significantly higher than T(Std) group (p < 0.0001). The 30-day MACE rates in E(B) (4.2%), E(B + Inf) (4.5%) and T(Adv) (4.2%) were significantly lower than T(Std) group (12.5%) (p < 0.01).

CONCLUSIONS

Standard dose Tirofiban results in significantly lower rates of GpIIb/IIIa receptor occupancy ratio and this correlated with higher incidence of 30-day MACE in high-risk ACS patients undergoing PCI.

Dosimetric comparison of standard three-dimensional conformal radiotherapy followed by intensity-modulated radiotherapy boost schedule (sequential IMRT plan) with simultaneous integrated boost-IMRT (SIB IMRT) treatment plan in patients with localized carcinoma prostate

Aims:

Dosimeteric and radiobiological comparison of two radiation schedules in localized carcinoma prostate: Standard Three-Dimensional Conformal Radiotherapy (3DCRT) followed by Intensity Modulated Radiotherapy (IMRT) boost (sequential-IMRT) with Simultaneous Integrated Boost IMRT (SIB-IMRT).

Material and Methods:

Thirty patients were enrolled. In all, the target consisted of PTV P + SV (Prostate and seminal vesicles) and PTV LN (lymph nodes) where PTV refers to planning target volume and the critical structures included: bladder, rectum and small bowel. All patients were treated with sequential-IMRT plan, but for dosimetric comparison, SIB-IMRT plan was also created. The prescription dose to PTV P + SV was 74 Gy in both strategies but with different dose per fraction, however, the dose to PTV LN was 50 Gy delivered in 25 fractions over 5 weeks for sequential-IMRT and 54 Gy delivered in 27 fractions over 5.5 weeks for SIB-IMRT. The treatment plans were compared in terms of dose–volume histograms. Also, Tumor Control Probability (TCP) and Normal Tissue Complication Probability (NTCP) obtained with the two plans were compared.

Results:

The volume of rectum receiving 70 Gy or more (V > 70 Gy) was reduced to 18.23% with SIB-IMRT from 22.81% with sequential-IMRT. SIB-IMRT reduced the mean doses to both bladder and rectum by 13% and 17%, respectively, as compared to sequential-IMRT. NTCP of 0.86 ± 0.75% and 0.01 ± 0.02% for the bladder, 5.87 ± 2.58% and 4.31 ± 2.61% for the rectum and 8.83 ± 7.08% and 8.25 ± 7.98% for the bowel was seen with sequential-IMRT and SIB-IMRT plans respectively.

Conclusions:

For equal PTV coverage, SIB-IMRT markedly reduced doses to critical structures, therefore should be considered as the strategy for dose escalation. SIB-IMRT achieves lesser NTCP than sequential-IMRT.

Potential of different white rot fungi to decolourize textile azo dyes in the absence of external carbon source

The decolourization of azo dyes by various white rot fungi was studied in the absence of an external carbon source. Although the decolourization abilities of strains used in this study are well documented, these strains have not been studied or compared for their decolourization abilities in the absence of an external carbon source. Decolourization of dyes was also studied in the presence of the external carbon source glucose. Daedalea flavida and Phanerochaete chrysosporium were able to decolourize the dyes in the absence of glucose. D. flavida exhibited a better ability to decolourize the dyes as compared with P. chrysosporium in the absence of glucose. Culture conditions were optimized to enhance the decolourization ability of D. flavida. Shaking of cultures inhibited the decolourization of Amaranth by D. flavida. The optimum culture conditions were 36 degrees C and pH 5.5 for decolourization of Amaranth in a stationary culture condition. We achieved 99% decolourization of Amaranth in 5 days under optimum conditions in the presence of glucose. D. flavida also decolourized the Amaranth with equal efficiency in the absence of glucose. To the best of the authors' knowledge, this is the first paper reporting the decolourization of dyes in the absence of an external carbon source by D. flavida.

Effect of acid-suppressive therapy on narrow band imaging findings in gastroesophageal reflux disease: a pilot study

Standard endoscopy is an insensitive test for gastroesophageal reflux disease (GERD). Narrow band imaging (NBI) endoscopy enhances visualization of the distal esophagus. NBI patterns like intrapapillary capillary loop (IPCL) dilatation, tortuosity, and increased number; microerosions; increased vascularity at the squamocolumnar junction (SCJ); ridge-villous pattern below the SCJ; and presence of columnar islands in the distal esophagus have been suggested as features of GERD. We evaluated the effect of proton pump inhibitor (PPI) therapy on NBI findings in GERD patients. Patients prospectively underwent NBI upper endoscopy before and after PPI therapy. NBI findings were recorded at each endoscopy. Twenty-one patients with GERD symptoms (mean age 60.0 years; males 90.5%; white 90.5%) were studied. After PPI therapy, there was a significant reduction in the proportion of patients with the following NBI features: IPCL tortuosity (90% vs. 4.8%, P < 0.0001), dilated IPCLs (86% vs. 9.5%, P < 0.0001), and increased vascularity at the SCJ (43% vs. 9.5%, P= 0.0082). PPI led to healing of all microerosions (71% vs. 0%, P < 0.0001) and disappearance of ridge-villous patterns below the SCJ (14% vs. 0%, P < 0.0001). There was no significant change in the proportion of patients with increased numbers of IPCLs pre- and post-PPI therapy (71% vs. 48%, P= 0.09) or columnar islands in the distal esophagus (38% vs. 29%, P= 0.31). In patients with GERD symptoms, NBI features suggestive of GERD respond to PPI; suggesting these features are truly acid-mediated. These findings need to be confirmed by randomized controlled trials.