Correction: Acridinedione as selective flouride ion chemosensor: a detailed spectroscopic and quantum mechanical investigation

Correction for ‘Acridinedione as selective flouride ion chemosensor: a detailed spectroscopic and quantum mechanical investigation’ by Nafees Iqbal et al., RSC Adv., 2018, 8, 1993–2003.

The authors regret that the interpretation of the fluorescence spectra of compound 7i published in the original article was incorrect. In the original article, it was reported that upon excitation at 380 nm, the fluorescence spectrum of compound 7i showed two emission bands at 450 nm and 770 nm (Fig. 5b of the original article). The signal at 770 nm (previously reported as an emission band), is instead a second order diffraction (an artefact of diffraction grating/spectrofluorometer monochromator), as revealed from the literature.^1,2 The authors thank a reader for highlighting this mistake.The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers.     

Combined experimental and computational study of Al2O3 catalyzed transamidation of secondary amides with amines

Amides are the most extensively used substances in both synthetic organic and bioorganic chemistry. Unfortunately, the traditional synthesis of amides suffers from some important drawbacks, including low atom efficiency, high catalyst loading, separation of products from the reaction mixture and production of byproducts. Al₂O₃ is an amphoteric catalyst that activates the carbonyl carbon of the secondary amide group and helps the C–N cleavage of the reactant amide group by attacking the N–H hydrogen. By using the concepts of amphoteric properties of Al₂O₃, amides were synthesized from secondary amides and amines in the presence of triethylamine solvent. Several aliphatic and aromatic amines were used for the transamidation of N-methylbenzamide in the presence of the Al₂O₃ catalyst. Moreover, using the Gaussian09 software at the DFT level, HUMO, LUMO and the intrinsic reaction coordinates (IRCs) have also been calculated to find out the transition state of the reaction and energy. In this study, five successful compounds were synthesized by the transamidation of secondary amides with amines using a reusable Al₂O₃ catalyst. The catalyst was reused several times with no significant loss in its catalytic activity. The products were purified by recrystallization and column chromatography techniques. This catalytic method is effective for the simultaneous activation of the carbonyl group and N–H bond by using the Al₂O₃ catalyst.

Amides are the most extensively used substances in both synthetic organic and bioorganic chemistry.     

Significance of Serum Tumor Marker Levels in Peritoneal Carcinomatosis of Appendiceal Origin

Background

The significance of tumor markers in patients with appendiceal carcinomatosis is poorly defined. We determined preoperative and postoperative tumor marker levels in patients undergoing cytoreductive surgery (CRS) and heated intraperitoneal chemoperfusion (HIPEC) and examined their association with clinicopathologic features and survival.

Methods

A total of 176 patients undergoing attempted CRS/HIPEC for appendiceal carcinomatosis had at least 1 tumor marker measured. Marker levels were correlated with tumor characteristics and oncologic outcomes. Kaplan–Meier curves and multivariate Cox regression models were used to identify prognostic factors affecting progression and survival.

Results

At least 1 marker was elevated prior to CRS/HIPEC in 70 % of patients (CEA, 54.1 %; CA19-9, 47.7 %; CA-125, 47.2 %). Among patients with elevated preoperative marker levels, normalization occurred postoperatively in 79.4 % for CEA, 92.3 % for CA19-9, and 60 % for CA-125. Absolute preoperative tumor marker levels correlated with peritoneal carcinomatosis index (PCI) (p < .0002), and the number of elevated markers was associated with PCI and progression-free survival (PFS). Elevated postoperative CEA level was associated with decreased PFS (median, 13 vs 36 months, p = .0008). On multivariate Cox regression analysis, elevated preoperative CA19-9 was associated with shorter PFS (hazard ratio [HR] 2.9, 95 % confidence interval [95 % CI] 1.5–5.3, p = .0008), whereas elevated CA-125 was associated with shorter overall survival (HR 2.6, 95 % CI 1.3–5.4, p = .01).

Conclusions

Most patients with appendiceal carcinomatosis will have at least 1 elevated tumor marker and will normalize following CRS/HIPEC, allowing for ongoing surveillance. CA19-9 is a promising biomarker for early progression following CRS/HIPEC, whereas CA-125 is associated with shorter survival.     

Extrathyroidal Uptake from Thyroid Carcinoma on 99mTc-Pertechnetate Scintigraphy

Three cases of imaging with 99mTc-pertechnetate (99mTcO4) and unusual positive lymph node uptake in the neck are reported hereby. Two cases were later diagnosed to be well-differentiated thyroid carcinoma, (DTC) with nodal metastasis. The third was a confirmed case of carcinoma thyroid that had presented with mass in the neck soon after surgery, being prepared for ablative dose of radioactive iodine (131I). All three were young females under 40 years of age. These 3 cases signify that extra thyroidal areas of uptake on a routine thyroid scan with 99mTcO4 can some time be due to thyroid carcinoma with regional metastases. Foci of metastasis in patients with DTC may be incidentlly detected with 99mTcO4 scan. Multinodular goiter with palpable lymph node should always be investigated for exclusion of malignancy. The patients underwent near total thyroidectomy and radical neck dissection; histopathology confirmed the scan findings.     

“Hands‐Free” Continuous Echocardiography during Treadmill Exercise Using a Novel Ultrasound Transducer

Background: Echocardiographic imaging using a handheld transducer in conjunction with treadmill exercise testing is commonly used for the diagnosis of coronary artery disease. Motion of the hand and the transducer during peak exercise preclude optimal imaging. To circumvent the limitations of handheld transducers, we developed a low profile transducer (CONTISON) which can be attached to the chest wall for continuous cardiac imaging. Methods and Results: This feasibility study was performed in 10 normal male subjects (28 to 36 years). The ultrasound transducer was placed in the third or fourth intercostal space at the left sternal border to permit imaging of the left ventricle in its short axis. The transducer was interfaced with a commercially available ultrasound machine. The left ventricle was imaged at rest and while subjects exercised according to a standard Bruce protocol. All segments of the left ventricular short axis were seen at rest and peak exercise. Increased left ventricular wall thickening and wall motion were seen at peak exercise. There were no complications from the procedure. Conclusion: We demonstrated the feasibility of hands‐free left ventricular imaging during treadmill exercise using the CONTISON transducer. Further evaluation of the technique to detect stress‐induced wall motion abnormalities, as a means of diagnosing myocardial ischemia, appears warranted. (ECHOCARDIOGRAPHY 2010;27:563‐566)     

Optimization,in vitro release and toxicity evaluation of novel pH sensitive itaconic acid-g-poly(acrylamide)/sterculia gum semi-interpenetrating networks

BackgroundIn recent era, pH sensitive polymeric carriers that combines the materials engineering and medicine is gaining researcher’s attention as they maximizes drug concentration at site of absorption and reduces side effects for e.g. orally administered cetirizine HCl (CTZ HCl) upsets the stomach and furthermore shows high intestinal absorption. Thus, development of pH sensitive hydrogels with sufficient mechanical strength will be good candidate to address this issue.MethodsHere, we developed pH sensitive itaconic acid-g-poly(acrylamide)/sterculia gum (IA-g-poly(AM)/sterculia gum) semi-interpenetrating network (semi-IPN) by free radical polymerization technique for intestinal delivery of CTZ HCL.ResultsOptimized formulation (I5) with 6% w/w IA showed negligible swelling at pH 1.2, and maximum swelling at pH 7.4. Solid state characterization of optimized formulation showed successful development of semi-IPN structure and incorporation of drug without any noticeable drug-carrier interaction. In vitro release study showed biphasic pH dependent release of CTZ HCl, where initial burst release was observed at acidic pH followed by sustained release at basic pH. Acute oral toxicity and histopathological studies confirmed the non-toxic nature of IA-g-poly(AM)/sterculia gum.ConclusionConclusively, developed biocompatible semi-IPN hydrogels with sufficient pH sensitivity and mechanical strength could serve as a potential carrier for intestinal delivery of CTZ HCL to maximize its absorption and reduce side effects.Graphical abstract Supplementary InformationThe online version contains supplementary material available at 10.1007/s40199-021-00395-8.