Clinicopathological and immunohistochemical study of pulmonary neuroendocrine tumors - A single-institute experience.

INTRODUCTION: Pulmonary neuroendocrine tumors (NETs) comprise a spectrum of tumors ranging from indolent to highly aggressive neoplasm. This study aims to study the clinicopathological and immunohistochemical features of NETs and assess the sensitivity of various IHC markers. MATERIALS AND METHODS: All consecutive cases of pulmonary NETs diagnosed from January 2016 to June 2019 were analyzed retrospectively. The routine hematoxylin- and eosin-stained sections along with immunohistochemistry (IHC) slides were reviewed. IHC was done using a panel of markers which included synaptophysin, chromogranin, CD56, thyroid transcription factor-1 (TTF-1), p-40, napsin-A, and ki67. RESULTS: Of total number of 53 patients, diagnosis was made on biopsy in 40 patients and resection specimen in 13 patients. Small cell lung carcinoma was the most common (31 cases), followed by 16 cases of typical carcinoid, 5 cases of atypical carcinoid, and 1 case of combined SCLC. Both synaptophysin and chromogranin were positive in all the cases of typical carcinoid. Synaptophysin had better sensitivity than chromogranin in atypical carcinoid and small cell carcinoma. CD56 was positive in 8 out of 9 cases done. TTF-1 was negative in all the cases of typical carcinoid. The sensitivity of TTF-1 in small cell carcinoma was 85.19%. The mean Ki67 labeling index was 1.4%, 6.6%, and 65.6% in typical, atypical carcinoid, and small cell carcinomas, respectively. CONCLUSION: Synaptophysin was more sensitive than chromogranin, especially in atypical carcinoid and small cell carcinoma. TTF-1 along with high Ki67 differentiates small cell carcinoma from carcinoid.

Percutaneous core needle biopsy in the diagnosis of lung lesions: An experience on 280 consecutive cases from a university hospital in southern India.

CONTEXT: Percutaneous needle biopsy of lung (PCNBL) is advantageous over bronchoscopic biopsies to obtain adequate sample for peripheral lung lesions. OBJECTIVE: The objective was to evaluate the diagnostic yield of image-guided PCNBL in the diagnosis of lung lesions and to classify lung carcinomas as per the recently proposed International Association for the Study of Lung Cancer (IASLC)/American Thoracic Society/European Respiratory Society classification for small biopsies modified and adopted by the World Health Organization, 2015. MATERIALS AND METHODS: A total of 280 image-guided PCNBL were analyzed. The radiological findings and routine hematoxylin and eosin (H&E)-stained sections along with immunohistochemistry (IHC) were analyzed in all the cases. Molecular testing was done depending on tissue diagnosis and availability. RESULTS: Majority (81%) were diagnosed as malignant lesions, with adenocarcinoma (ADC) being the most common. More than 70% were diagnosed on H&E morphology alone, with thirty cases requiring IHC to categorize as ADC. Nearly 60% were categorized as squamous cell carcinoma on morphology alone and the rest required IHC. Though TTF1 showed higher sensitivity than napsin A, the latter is more specific. Both p63 and p40 were found to be highly sensitive for squamous cell carcinoma, but p40 was more specific than p63. Epidermal growth factor receptor could be evaluated on 94.4% of ADC samples, indicating good yield for molecular testing. CONCLUSION: PCNBL yields adequate sampling for tissue diagnosis and ancillary testing with minimal complications. The use of IHC markers reduces the number of non-small-cell not otherwise specified cases significantly.

Synthesis of coumarin analogs appended with quinoline and thiazole moiety and their apoptogenic role against murine ascitic carcinoma.

The synthesis and antiproliferative effect of a series of quinoline and thiazole containing coumarin analogs 12a-d and 13a-f respectively, on mice leukemic cells was performed. The chemical structures of newly synthesized compounds were confirmed by IR, 1H NMR, 13C NMR and mass spectral analysis. The result indicates that, 7-methoxy-2-oxo-2H-chromene-3-carboxylic acid [4-(4-methoxy-phenyl)-thiazol-2-yl]-amide (13f) showed potent activity against EAC and DLA cells in MTT (15.3 µM), tryphan blue (15.6 µM) and LDH (14.2 µM) leak assay with 5-fluorouracil as a standard. Further, the anti-neoplastic effect of the compound 13f was verified against Ehrlich ascites tumour by BrdU incorporation, TUNEL, FACS and DNA fragmentation assays. Experimental data showed that compound 13f induces the apoptotic cell death by activating apoptotic factors such as caspase-8 &-3, CAD, Cleaved PARP, γ-H2AX and by degrading genomic DNA of cancer cells and thereby decreasing the ascitic tumour development in mice. Besides, compound 13f was also subjected for docking studies to approve the in vitro and in vivo studies. The data revealed that the compound 13f has very good interaction with caspase 3 protein by binding with amino acid Arg 207 through hydrogen bond.

Thioacids - synthons for amide bond formation and ligation reactions: assembly of peptides and peptidomimetics.

The synthesis of α-amino thioacids and peptide thioacids and their applications in chemoselective amide bond formation, ligation of peptides/proteins/glycopeptides and synthesis of peptidomimetics are reviewed. A variety of successful methods including both C-terminal and N-terminal activations for the coupling of α-amino thioacids and peptide thioacids have ascertained the thioacid-based protocol as a benign alternative to some of the traditional methods of amide/peptide bond formation which employs carboxyl activation. In addition to the couplings involving unprotected peptide fragments and solid phase synthesis, their use in the synthesis of different classes of peptidomimetics such as thioxopeptides, imide conjugates and acylsulfonamide-peptide conjugates only illustrates the versatility of this functionality in generating diverse classes of molecules, some of which are relevant to drug discovery and chemical biology. A note on more reactive seleno counterparts of thioacids, which can be useful in selective cases, is provided.

Design, Synthesis and Biological Evaluation of Novel Urea and Thiourea Bearing thieno[3,2-d]-pyrimidines as PI3 Kinase Inhibitors.

BACKGROUND: Phosphatidylinositol-3-kinase α (PI3Kα) is a ubiquitous intracellular enzyme, mainly involved in intracellular signaling pathways, promotes cellular growth, proliferation, and differentiation. Therefore, inhibition of PI3K can be a hotspot in molecular targeted therapy for the treatment of cancer. METHODS: The present research work involves molecular docking studies performed to screen derivatives of urea and thiourea bearing thieno [3,2-d]-pyrimidines against the active site of PI3K enzyme using MOE.2008.10. The designed structures (6a-f) and (7a-j) were synthesized by the facile synthetic methods and evaluated for their anticancer activity against HT-29 and MCF-7 cell lines and inhibitory activity against PI3Kα enzyme. RESULTS: Among the tested compounds, 4-(4-(2-(3-(pyrimidin-2-yl)thioureido)ethyl)piperazin-1-yl)thieno[3,2- d]pyrimidine-6-carboxamide (7f) showed the highest anticancer activity against HT-29 and MCF-7 cell lines with IC50 values of 2.18 µM and 4.25 µM, respectively. Further, the same compound also exhibited potent PI3Kα inhibitory activity with IC50 value of 1.26 µM. CONCLUSION: Docking studies supported the initial pharmacophoric hypothesis and suggested a mode of interaction at the active binding site of PI3Kα, demonstrating that the target compounds were potential inhibitory agents for cancer therapy.

Thienopyrimidines as novel inhibitors of Mycobacterium tuberculosis: synthesis and in-vitro studies.

A series of novel 5,6-unsubstituted thieno-[2,3-d]-pyrimidines has been synthesized and tested for growth inhibition of Mycobacterium tuberculosis H37Rv. Of twelve compounds synthesized eleven have shown antimycobacterial activity that differs in potency. Compounds 7b, 7c, 7d, 7e, 7f, and 7g exhibited good antimycobacterial activity. MIC values of the compounds tested were comparable with pyrazinamide. Six compounds which have shown good antimycobacterial activity were also subjected for cytotoxicity studies and were found to possess poor cytotoxicity. The study indicates the definite need for focusing attention on thienopyrimidines for further lead optimization.

Synthesis and xanthine oxidase inhibitory activity of 7-methyl-2-(phenoxymethyl)-5H-[1,3,4]thiadiazolo[3,2-a]pyrimidin-5-one derivatives.

An elevated level of blood uric acid (hyperuricemia) is the underlying cause of gout. Xanthine oxidase is the key enzyme that catalyzes the oxidation of hypoxanthine to xanthine and then to uric acid. Allopurinol, a widely used xanthine oxidase inhibitor is the most commonly used drug to treat gout. However, a small but significant portion of the population suffers from adverse effects of allopurinol that includes gastrointestinal upset, skin rashes and hypersensitivity reactions. Moreover, an elevated level of uric acid is considered as an independent risk factor for cardiovascular diseases. Therefore use of allopurinol-like drugs with minimum side effects is the ideal drug of choice against gout. In this study, we report the synthesis of a series of pyrimidin-5-one analogues as effective and a new class of xanthine oxidase inhibitors. All the synthesized pyrimidin-5-one analogues are characterized by spectroscopic techniques and elemental analysis. Four (6a, 6b, 6d and 6f) out of 20 synthesized molecules in this class showed good inhibition against three different sources of xanthine oxidase, which were more potent than allopurinol based on their respective IC(50) values. Molecular modeling and docking studies revealed that the molecule 6a has very good interactions with the Molybdenum-Oxygen-Sulfur (MOS) complex a key component in xanthine oxidase. These results highlight the identification of a new class of xanthine oxidase inhibitors that have potential to be more efficacious, than allopurinol, to treat gout and possibly against cardiovascular diseases.

Acetylcholine and memory-enhancing activity of Ficus racemosa bark.

BACKGROUND: Alzheimer's disease (AD) is a progressive neurodegenerative disorder resulting in dementia and enhancement of acetylcholine (Ach) levels in brain using acetylcholinesterase inhibitors is one of the most important approaches for the treatment of AD. METHODS: In this study, aqueous extract of Ficus racemosa Linn. (Moraceae) bark having anti-inflammatory, antioxidant, and anticholinesterase activity was evaluated for its ability to enhance Ach levels, and to ascertain its antidementia activity in rats. This work was carried out under the assumption that the F. racemosa extract may show combination of actions which could be beneficial in the treatment of AD, such as neuroprotection, attributed to antioxidant and anti-infl ammatory property and may elevate levels of Ach like Ficus hispida extract reported earlier. RESULTS: Administration of the extract at two levels viz., 250 and 500 mg/kg signifi cantly raised (P ≤ 0.05) Ach levels in hippocampi of rats compared to control. The percentage enhancement in Ach levels was found to be 22% and 38%, respectively. Further, the extract at both dosage levels elicited signifi cant reduction (P ≤ 0.05) in transfer latency on elevated plus-maze, which was used as an exteroceptive behavioral model to evaluate memory in rats. CONCLUSION: It is inferred that it would be worthwhile to explore the potential of F. racemosa in the management of Alzheimer disease.

Synthesis and pharmacological evaluation of novel N-alkyl/aryl substituted thiazolidinone arecoline analogues as muscarinic receptor 1 agonist in Alzheimer's dementia models.

Earlier we have reported the effect of arecoline thiazolidinone and morpholino arecoline analogues as muscarinic receptor 1 agonist in Alzheimer's dementia models. To elucidate further our SAR study on the chemistry and muscarinic receptor binding efficacy, a series of novel N-alkyl/aryl substituted thiazolidinone arecoline analogues 6(a-m) were designed and synthesized from 3-pyridine carboxaldehyde by reacting with different amines in the presence of gamma-ferrite as catalyst and subjected to in vitro muscarinic receptor binding studies using male Wistar rat brain membrane homogenate and extended to in vivo pharmacological evaluation of memory and learning in male Wistar rats. Derivative 6j having diphenylamine moiety attached to nitrogen of thiazolidinone showed significant affinity for the M1 receptor binding.

Muscarinic receptor 1 agonist activity of novel N-arylthioureas substituted 3-morpholino arecoline derivatives in Alzheimer's presenile dementia models.

As part of our continuing effort aimed at the development of selective, efficacious and centrally active M1 muscarinic agonists for the treatment of Alzheimer's presenile dementia, a series of N-arylthioureas substituted 3-morpholino arecoline derivatives 9(a-j) were synthesized by using N-benzyl amino ethanol coupling with alpha-bromo acetyl pyridine followed by reduction and cyclization to develop a new class of M1 receptor agonists. Subsequently the synthesized compounds were subjected to in vitro radioligand M1 receptor affinity studies, IP3 formation studies and also to in vivo pharmacological evaluation of memory and learning in male Wistar rats. Derivatives with chloro (9f) and methoxy (9c) groups on the para position of the benzene ring attached to the nitrogen of thiourea showed several fold high affinity for the M1 receptor (in vitro) among all the synthesized molecules 9(a-j), and also significantly elevated IP3 levels and as well elicited beneficial effects in vivo in memory and learning models in rats (rodent memory evaluation, plus and Y maze studies).

Effect of novel N-aryl sulfonamide substituted 3-morpholino arecoline derivatives as muscarinic receptor 1 agonists in Alzheimer's dementia models.

A series of novel, potent, and selective muscarinic receptor 1 agonists (M1 receptor agonists) that employ a key N-substituted morpholine Arecoline moiety has been synthesized as part of research effort for the therapy of Alzheimer's diseases. The ester group of arecoline (which is reported as muscarinic agonist) has been replaced by N-substituted morpholine ring. The structure-activity relationship reveals that the electron donating 4-substituted sulfonyl derivatives (9a, 9b, 9c, and 9e) on the nitrogen atom of the morpholine ring increases the affinity of M1 receptor binding 50- to 80-fold greater than the corresponding arecoline. Other derivatives also showed considerable M1 receptor binding affinity.

Effect of novel arecoline thiazolidinones as muscarinic receptor 1 agonist in Alzheimer's dementia models.

The discovery of cholinergic deficit in Alzheimer's disease (AD) patient's brain has triggered research efforts, using cholinomimetic approaches for their efficacy in AD therapy. Various therapies may be of potential clinical use in AD. Among these are cholinergic agents, which include muscarinic agonists, acetylcholinesterase inhibitors, and acetylcholine releasing agents. One of the muscarinic agonists tested in AD is arecoline and its bioisosters, which are widely explored as muscarinic receptor 1 agonist (M1 receptor agonist) in AD research. In this regard, five-membered heterocyclic ring system attached arecoline basic nucleus (N-methyl tetrahydropyridines) at third position has been extensively researched on. The present research involved synthesis of arecoline thiazolidinones 5(a-j) by using dipolar addition of 3-aminopyridine and alkyl/aryl carboxaldehydes in presence of gamma ferrite as catalyst. The resulting products were methylated and reduced to get desired products. Subsequently the synthesized arecoline thiazolidinones were subjected to in vitro muscarinic receptor binding studies using male Wistar rat brain (cerebral cortex) membrane homogenate and extended this in vitro study to in vivo pharmacological evaluation of memory and learning in male Wistar rats. Four derivatives (5a-5c and 5e) showed considerable M1 receptor binding affinity (in vitro) and elicited beneficial effects in vivo memory and learning models (Rodent memory evaluation, plus and Y maze studies).