Self-reducing intrathoracic organo-axial gastric volvulus with paraoesophageal hiatus hernia in a toddler.

A toddler presented with complaints of multiple episodes of vomiting lasting 1 week. He had a history of similar episodes of vomiting several times as an infant. Clinically, he was underweight and had tachypnoea and tachycardia. Laboratory investigations revealed hyponatraemic metabolic acidosis. His chest radiograph revealed an intrathoracic herniation of the stomach with an atypical presence towards the right hemithorax, suggestive of a torsion. A contrast-enhanced CT of the chest and abdomen confirmed an intrathoracic gastric herniation, with an organo-axial gastric volvulus, with no features of strangulation. He underwent an emergency laparotomy and intraoperatively the stomach was found to have reduced to its intra-abdominal position, and the hernia and volvulus had also self-reduced. In view of the multiple symptomatic episodes, an anterior gastropexy was performed to prevent recurrences. The patient recuperated well and has not had any recurrences in the follow-up period. This report adds to the minimalistic literature.

Endovascular salvage of tubercular aortitis presenting as descending thoracic aortic pseudoaneurysm in association with vertebral tuberculosis.

A gentleman in his late 30s presented with a history of evening rise of temperature and generalised malaise of 1-week duration. He had associated upper back pain with tingling and numbness of both lower limbs. An unexplained episode of hypotension with hemoptysis propelled a computed tomography (CT) examination of chest which was suggestive of a pseudoaneurysm of the posterior wall of descending thoracic aorta in the vicinity of the Pott's spine with a prevertebral and paravertebral abscess, for which he was referred to vascular surgeons.Tubercular involvement of vasculature is a rare disease, aortic involvement even rarer. Less than 50 cases of vertebral tuberculosis with tubercular thoracic aortic aneurysm have been reported in the medical literature, but the disease carries a colossal mortality and morbidity.After a multidisciplinary teamwork, thoracic endovascular aortic repair was done for exclusion of the aneurysmal segment, with simultaneous antitubercular and broad-spectrum antibiotic chemotherapy. The patient recuperated well.

Corrigendum to The Competence of 7,8-Diacetoxy-4-Methylcoumarin and Other Polyphenolic Acetates in Mitigating the Oxidative Stress and their Role in Angiogenesis.

In the Original Research Article entitled "The Competence of 7, 8-Diacetoxy-4-methylcoumarin and other Polyphenolic Acetates in Mitigating the Oxidative Stress and their Role in Angiogenesis" Published in Current Topics in Medicinal Chemistry, 2015, Vol. 15, No. 2, on page no. 179, the order of author names was rearranged because second authorship is acceptable as they only acknowledge the first and the second authorship as per the new policies of Medical Council of India. The order of authors should be read as follows: Rini Joshi, Vishwajeet Rohil, Shvetambri Arora, Sushma Manral, Ajit Kumar, Sanjay Goel, Nivedita Priya, Prabhjoth Singh, Prija Ponnan, Suvro Chatterji, Bilikere S. Dwarakanath, Daman Saluja, Diwan S. Rawat, Ashok K. Prasad, Luciano Saso, Ekta Kohli, Anthony L. DePass, Marc E. Bracke, Virinder S. Parmar and Hanumantharao G. Raj.

The Competence of 7,8-Diacetoxy-4-Methylcoumarin and Other Polyphenolic Acetates in Mitigating the Oxidative Stress and their Role in Angiogenesis.

The potential role of polyphenolic acetate (PA) in causing diverse biological and pharmacological actions has been well studied in our laboratory. Our investigations, for the first time, established the role of calreticulin transacetylase (CRTAase) in catalyzing the acetylation of nitric oxide synthase (NOS) by Pas leading to robust activation of NOS. 7, 8- Diacetoxy-4-methylcoumarin (DAMC) and other acetoxycoumarins augmented the expression of thioredoxin (TRX) and vascular endothelial growth factor (VEGF) in human peripheral blood mononuclear cells (PBMCs). These findings substantiated our earlier observations that DAMC was a superb inducer of angiogenesis. The enhanced expression of thioredoxin reductase (TRXR) and diminished expression of thioredoxin interacting protein (TRXIP) leading to increased expression and activity of TRX in PBMCs due to the action of DAMC was revealed by real time RT-PCR analysis. The possible activation of TRX due to acetylation was confirmed by the fact that TRX activity of PBMCs was enhanced by various acetoxycoumarins in tune with their affinities to CRTAase as substrates. DAMC caused enhanced production of NO by way of acetylation of NOS as mentioned above and thereby acted as an inducer of VEGF. Real time RT-PCR and VEGF ELISA results also revealed the overexpression of TRX. DAMC and other PAs were found to reduce the oxidative stress in cells as proved by significant reduction of intracellular ROS levels. Thus, the crucial role of TRX in DAMC-induced angiogenesis with the involvement of VEGF was established.

The Competence Of 7,8-Diacetoxy-4-Methylcoumarinand Other Polyphenolic Acetates In Mitigating The Oxidative Stress And Their Role In Angiogenesis.

The potential role of polyphenolic acetate (PA) in causing diverse biological and pharmacological actions has been well studied in our laboratory. Our investigations, for the first time, established the role of calreticulin transacetylase (CRTAase) in catalyzing the acetylation of nitric oxide synthase (NOS) by Pas leading to robust activation of NOS. 7, 8-Diacetoxy-4-methylcoumarin (DAMC) and other acetoxycoumarins augmented the expression of thioredoxin (TRX) and vascular endothelial growth factor (VEGF) in human peripheral blood mononuclear cells (PBMCs). These findings substantiated our earlier observations that DAMC was a superb inducer of angiogenesis. The enhanced expression of thioredoxin reductase (TRXR) and diminished expression of thioredoxin interacting protein (TRXIP) leading to increased expression and activity of TRX in PBMCs due to the action of DAMC was revealed by real time RT-PCR analysis. The possible activation of TRX due to acetylation was confirmed by the fact that TRX activity of PBMCs was enhanced by variousacetoxycoumarins in tune with their affinities to CRTAase as substrates. DAMC caused enhanced production of NO by way of acetylation of NOS as mentioned above and thereby acted as an inducer of VEGF. Real time RT-PCR and VEGF ELISA results also revealed the overexpression of TRX. DAMC and other PAs were found to reduce the oxidative stress in cells as proved by significant reduction of intracellular ROS levels. Thus, the crucial role of TRX in DAMC-induced angiogenesis with the involvement of VEGF was established.

Calreticulin transacetylase mediated upregulation of thioredoxin by 7,8-diacetoxy-4-methylcoumarin enhances the antioxidant potential and the expression of vascular endothelial growth factor in peripheral blood mononuclear cells.

Extensive research carried out in our group on polyphenolic acetates (PAs) substantiated the potential role of PAs in causing diverse biological and pharmacological actions. Our earlier investigations firmly established the calreticulin transacetylase (CRTAase) catalyzed activation of nitric oxide synthase (NOS) by PAs. In this report, we have studied the effect of 7,8-diacetoxy-4-methylcoumarin (DAMC, a model PA) and other acetoxy coumarins on the thioredoxin and VEGF expression in human peripheral blood mononuclear cells (PBMCs), with a view to substantiate our earlier observation that DAMC was a superb inducer of angiogenesis. Real time RT-PCR analysis revealed the enhanced expression of thioredoxin reductase (TRXR) and diminished expression of thioredoxin interacting protein (TRXIP) leading to the increased expression and activity of thioredoxin (TRX) in PBMCs due to the the action of DAMC. The fact that TRX activity of PBMCs was enhanced by various acetoxy coumarins in tune with their affinity to CRTAase as substrate, suggested the possible activation of TRX due to acetylation. The overexpression of thioredoxin was found to correlate with that of VEGF as proved by real time RT-PCR and VEGF -ELISA results, apart from the DAMC-caused enhanced production of NO acting as an inducer of VEGF. Moreover, the intracellular ROS levels were also found to be reduced drastically, by DAMC thus reducing the oxidative stress in cells. These observations strongly evidenced the crucial role of TRX in DAMC-induced tissue angiogenesis with the involvement of VEGF.

Calreticulin Transacetylase mediated activation of human platelet nitric oxide synthase by acetyl group donor compounds.

Polyphenols have attracted immense interest because of their diverse biological and pharmacological activities. Surprisingly, not much is documented about the biological activities of acetoxy derivatives of polyphenol called polyphenolic acetates (PA). In our previous reports, we have conclusively established the Calreticulin Transacetylase (CRTAase) catalyzed activation of neuronal nitric oxide synthase (nNOS) and tumor necrosis factor-α (TNF-α) induced nitric oxide synthase (iNOS) by PA. In the present work, specificity of CRTAase to various classes of PA was characterized in human platelet. The effect of PA, on platelet NOS and intracellular cyclic guanosine monophosphate (cGMP), and adenosine diphosphate (ADP)-induced platelet aggregation were studied in an elaborated manner. Platelet CRTAase exhibited differential specificities to polyphenolic acetates upon incubation with l-arginine leading to activation of NOS. The intraplatelet generation of NO was studied by flowcytometry using DCFH-DA. The differential specificities of CRTAase to PA were found to positively correlate with increased production of NO upon incubation of PRP with PA and l-arginine. Further, the inhibitory effect of l-NAME on PA induced NO formation in platelets substantiated the CRTAase catalyzed activation of NOS. The real-time RT-PCR profile of NOS isoforms confirmed the preponderance of eNOS over iNOS in human platelets on treatment with PA. Western blot analysis also reiterated the differential pattern of acetylation of eNOS by PA. PA were also found effective in increasing the intraplatelet cGMP levels and inhibiting ADP-induced platelet aggregation. It is worth mentioning that the effects of PA were found to be in tune with the specificities of platelet CRTAase to PA as the substrates.

Normalization of deranged signal transduction in lymphocytes of COPD patients by the novel calcium channel blocker H-DHPM.

Investigations on the role of intracellular Ca(2+) ion concentration in the mechanism of development of COPD in smokers and non-smokers were carried out. The intracellular Ca(2+) levels were found to be increased in human lymphocytes in patients with COPD as compared to non-smokers and smokers without COPD. The investigations reveal an association in altered intracellular Ca(2+) regulation in lymphocytes and severity of COPD, by means of significant activation of Protein kinase C and inducible nitric oxide synthase (iNOS). The effect of a novel calcium channel blocker ethyl 4-(4'-heptanoyloxyphenyl)-6-methyl-3,4-dihydropyrimidin-2-one-5-carboxylate (H-DHPM) as a potential candidate for the treatment of COPD was also investigated. H-DHPM treated cells showed a decrease in intracellular Ca(2+) level as compared to the control cells. Molecular studies were carried out to evaluate the expression profile of NOS isoforms in human lymphocytes and it was shown that H-DHPM decreases the increased iNOS in COPD along with reestablishing the normal levels of endothelial nitric oxide synthase (eNOS). The results of H-DHPM were comparable with those of Amlodipine, a known calcium channel blocker. Calcium channel blocker H-DHPM proves to be a potential candidate for the treatment of COPD and further clinical studies are required to prove its role in the treatment of pulmonary hypertension (PH).

Prevention of benzene-induced genotoxicity in bone marrow and lung cells: superiority of polyphenolic acetates to polyphenols.

Previous investigations carried out in our laboratory have highlighted that 7,8-diacetoxy-4-methylcoumarin demonstrates a mechanism-based inhibition of cytochrome P450 (Cyt-P450) activities such as microsome-mediated aflatoxin B1 (AFB1) epoxidation, dealkylation of alkylated resorufin, and toxicokinetics of benzene. 7,8-Diacetoxy-4-methylcoumarin, quercetin pentaacetate, and ellagic acid peracetate were also found to be effective in giving the protection of AFB1-induced genotoxicity in rat's bone marrow and lung cells possibly due to acetylation of Cyt-P450 apoprotein mediated by acetoxy drug: protein transacetylase. Later, this transacetylase was identified as calreticulin, and the acetyltransferase function of calreticulin was appropriately termed calreticulin transacetylase. In this communication, we have focused on the superiority of several classes of polyphenolic acetates to polyphenols in the modification of Cyt-P450-linked mixed function oxidases (MFOs) such as 7-ethoxyresorufin O-deethylase (EROD) and pentoxyresorufin O-dealkylase (PROD). Special attention has also been focused on benzene-induced genotoxicity in bone marrow and lung cells. Results clearly indicated that polyphenolic acetates demonstrated time-dependent inhibition of Cyt-P450-linked MFOs, while parent polyphenols failed to demonstrate the same. Polyphenolic acetates were found to be more superior to polyphenols in preventing benzene-induced micronuclei formation. The pattern of inhibition of Cyt-P450-dependent MFOs and benzene-induced micronuclei formation by polyphenolic acetates was found in tune with their specificities to calreticulin transacetylase. These results further substantiated that inhibition of Cyt-P450-linked MFOs and benzene-induced genotoxicity in bone marrow and lung cells by polyphenolic acetates are mediated by the action of calreticulin transacetylase that catalyzes the acetylation of concerned proteins.

Calreticulin transacetylase catalyzed modification of the TNF-alpha mediated pathway in the human peripheral blood mononuclear cells by polyphenolic acetates.

Polyphenols, coumarin (1,2-benzopyrone) and chromone (1,4-benzopyrone), are naturally occurring constituent of variety of plant species. They have attracted immense interest because of their diverse pharmacological activities. Not much was known about biological activities of acetyl derivative (polyphenolic acetates) of parent polyphenols. In previous investigations, we have conclusively established calreticulin transacetylase catalyzed activation of endothelial nitric oxide synthase (eNOS) by polyphenolic acetates. In the present work, calreticulin transacetylase of human peripheral blood mononuclear cells was characterized with respect to specificity for various polyphenolic acetates and its role in the activation of TNF-alpha induced nitric oxide synthase (iNOS). Peripheral blood mononuclear cells incubated with a model polyphenolic acetate, 7,8-diacetoxy-4-methylcoumarin (DAMC), along with L-arginine caused activation of NOS. The incubation of peripheral blood mononuclear cells with TNF-alpha and DAMC resulted in increased production of NO as compared to TNF-alpha alone. This increased NO production was attenuated by l-Nomega-nitro-L-arginine methyl ester (L-NAME), a well known non-specific inhibitor of NOS, and 1400W (N-[3-(aminomethyl) benzyl] acetamidine), a specific inhibitor of human iNOS. These results substantiate the CRTAase catalyzed activation of iNOS. Further, expression of NOS isoforms by semi-quantitative PCR and real-time RT-PCR confirms the preponderance of iNOS in TNF-alpha treated peripheral blood mononuclear cells over the untreated one. It was also observed that polyphenolic acetates inhibit TNF-alpha mediated release of IL-6 from peripheral blood mononuclear cells.

Calreticulin transacylase: genesis, mechanism of action and biological applications.

Our earlier investigations have identified a unique enzyme in the endoplasmic reticulum (ER) termed Acetoxy Drug: Protein Transacetylase (TAase) catalyzing the transfer of acetyl group from polyphenolic acetates (PA) to certain receptor proteins (RP). An elegant assay procedure for TAase was developed based on the inhibition of glutathione S-transferase (GST) due to acetylation by a model acetoxycoumarin, 7, 8-Diacetoxy-4-methylcoumarin (DAMC). TAase purified from various mammalian tissue microsomes to homogeneity exhibited a molecular weight (M.wt) of 55kDa. Further, by N-terminal sequencing TAase was identified as Calreticulin (CR), a multifunctional Ca2+-binding protein in ER lumen. The identity of TAase with CR was evidenced by proteomics studies such as immunoreactivity with anti-CR antibody and mass spectrometry. This function of CR was termed Calreticulin transacetylase (CRTAase). CRTAase was also found to mediate the transfer of acetyl group from DAMC to RP such as NADPH Cytochrome c Reductase (CYPR) and Nitric Oxide Synthase (NOS). The autoacetylation of purified human placental CRTAase concomitant with the acetylation of RP by DAMC was observed. CRTAase activity was found to be inhibited by Ca2+. Our investigations on the individual domains (N, P and C) of CR from a nematode Haemonchus contortus revealed that the P-domain alone was found to possess CRTAase activity. Based on the observation that the autoacetylated CR was a stable intermediate in the CRTAase catalyzed protein acetylation by PA, a putative mechanism was proposed. Further, CRTAase was also found capable of transferring propionyl group from a propoxy derivative of polyphenol, 7,8-Dipropoxy-4-methylcoumarin (DPMC) to RP and concomitant autopropionylation of CR was encountered. Hence, CRTAase was assigned the general term Calreticulin Transacylase. Also, CRTAase was found to act upon the biological acyl group donors, acetyl CoA and propionyl CoA. CRTAase mediated modulation of specific functional proteins by way of acylation was exploited to elicit the biological applications of PA.