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Abstract
Teratomas are the benign tumours, which may occur anywhere in the body. Development of these lesions in the oral cavity is extremely rare. In the oral cavity, they usually arise in the midline, in the floor of mouth. Infrequently, they may be seen in the tongue proper. We hereby, present a case of swelling tongue in 56 years female diagnosed as teratoma.
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Chowdhury SR, Manna S, Saha P, Basak RK, Sen R, Roy D, Adhikari B. Composition analysis and material characterization of an emulsifying extracellular polysaccharide (EPS) produced by Bacillus megaterium RB-05: a hydrodynamic sediment-attached isolate of freshwater origin. J Appl Microbiol 2011; 111:1381-93. [PMID: 21973188 DOI: 10.1111/j.1365-2672.2011.05162.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
AIMS This work was aimed to isolate, purify and characterize an extracellular polysaccharide (EPS) produced by a freshwater dynamic sediment-attached micro-organism, Bacillus megaterium RB-05, and study its emulsifying potential in different hydrocarbon media. METHODS AND RESULTS Bacillus megaterium RB-05 was found to produce EPSs in glucose mineral salts medium, and maximum yield (0.864 g l(-1) ) was achieved after 24-h incubation. The recovery rates of the polysaccharide material by ion-exchange and gel filtration chromatography were around 67 and 93%, respectively. As evident from HPLC and FT-IR analyses, the polysaccharide was found to be a heteropolymer-containing glucose, galactose, mannose, arabinose, fucose and N-acetyl glucosamine. Different oligosaccharide combinations namely hexose(3), hexose(4), hexose(5) deoxyhexose(1) and hexose(5) deoxyhexose(1) pentose(3) were obtained after partial hydrolysis of the polymer using MALDI-ToF-MS. The polysaccharide with an average molecular weight of 170 kDa and thermal stability up to 180°C showed pseudoplastic rheology and significant emulsifying activity in hydrocarbon media. CONCLUSIONS Isolated polysaccharide was found to be of high molecular weight and thermally stable. The purified EPS fraction was composed of hexose, pentose and deoxyhexose sugar residues, which is a rare combination for bacterial polysaccharides. Emulsifying property was either better or comparable to that of other commercially available natural gums and polysaccharides. SIGNIFICANCE AND IMPACT OF THE STUDY This is probably one of the few reports about characterizing an emulsifying EPS produced by a freshwater sediment-attached bacterium. The results of this study contribute to understand the influence of chemical composition and material properties of a new microbial polysaccharide on its application in industrial biotechnology. Furthermore, this work reconfirms freshwater dynamic sediment as a potential habitat for bioprospecting extracellular polymer-producing bacteria. This study will improve our knowledge on the exploitation of a nonconventional renewable resource, which also seems to be ecologically significant.
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Sen R, Chatterjee M. Plant derived therapeutics for the treatment of Leishmaniasis. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2011; 18:1056-69. [PMID: 21596544 DOI: 10.1016/j.phymed.2011.03.004] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2010] [Revised: 12/20/2010] [Indexed: 05/17/2023]
Abstract
Diseases caused by insect borne trypanosomatid parasites are significant, yet remain a neglected public health problem. Leishmania, a unicellular protozoan parasite is the causative organism of Leishmaniasis and is transmitted by female phlebotamine sandflies affecting millions of people worldwide. In the wake of resistance to pentavalent antimonial drugs, new therapeutic alternatives are desirable. The plant kingdom has in the past provided several affordable compounds and this review aims to provide an overview of the current status of available leishmanicidal plant derived compounds that are effective singly or in combination with conventional anti-leishmanial drugs, yet are non toxic to mammalian host cells. Furthermore, delineation of the contributory biochemical mechanisms involved in mediating their effect would help develop new chemotherapeutic approaches.
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Kodali VP, Perali RS, Sen R. Purification and partial elucidation of the structure of an antioxidant carbohydrate biopolymer from the probiotic bacterium Bacillus coagulans RK-02. JOURNAL OF NATURAL PRODUCTS 2011; 74:1692-1697. [PMID: 21800834 DOI: 10.1021/np1008448] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
An exopolysaccharide (EPS) was isolated from Bacillus coagulans RK-02 and purified by size exclusion chromatography. The purified, homogeneous EPS had an average molecular weight of ∼3 × 10⁴ Da by comparison with FITC-labeled dextran standards. In vivo evaluations showed that, like other reported polysaccharides, this EPS displayed significant antioxidant activity. FTIR spectroscopy analysis showed the presence of hydroxy, carboxy, and α-glycosidic linkages and a mannose residue. GC analysis indicated that the EPS was a heteropolymer composed of glucose, mannose, galactose, glucosamine, and fucose as monomeric constituent units. Partial elucidation of the structure of the carbohydrate biopolymer based on GC-MS and NMR analysis showed the presence of two unique sets of tetrasaccharide repeating units that have 1→3 and 1→6 glycosidic linkages. This is also the first report of a Gram-positive bacterial polysaccharide with both fucose as a sugar monomer and 1→3 and 1→6 glycosidic linkages in the molecular backbone.
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Bhadada SK, Bhansali A, Das S, Singh R, Sen R, Agarwal A, Mittal B, Nahar U, Dutta P, Khandelwal N. Fibrous dysplasia & McCune-Albright syndrome: an experience from a tertiary care centre in north India. Indian J Med Res 2011; 133:504-9. [PMID: 21623035 PMCID: PMC3121281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND & OBJECTIVES Fibrous dysplasia (FD) is a rare metabolic bone disease and information available from India is limited to only anecdotal case reports. We describe the clinical profile and therapeutic outcome of 25 patients with FD observed over a period of 14 yr in a tertiary care centre from north India. METHODS In this retrospective study patients (n = 25) with diagnosis of fibrous dysplasia based on either classical radiological features and/or histological evidence on bone biopsy, were analyzed. Associated endocrinopathies if any, were evaluated. The diagnosis of McCune Albright syndrome (MAS) was considered when fibrous dysplasia was accompanied by either café-au-lait macules and/or endocrinopathies. The clinical presentation, biochemical parameters and imaging were analysed. Seven patients received bisphosphonate therapy. The final outcome and side effects were noted. RESULTS Age of the patients ranged from 7 to 48 yr (mean ± SD, 24.2 ± 11.4 yr) with a lag time between onset of symptoms and presentation ranging from 1 to 20 yr (mean ± SD, 6.6 ± 6.2 yr). The mean duration of follow up was 3.5 ± 2.1 yr. Eighteen (72%) patients had polyostotic disease while the remaining had monostotic FD. Eight patients had endocrinopathies: five had acromegaly, one each had gonadotropin independent precocious puberty (GIPP), hyperthyroidism and hypophosphatemic rickets. One child with GIPP later developed hyperthyroidism. McCune Albright syndrome was observed in 10 (40%) patients. A majority of the patients underwent various minor or major surgical procedures and seven patients received bisphosphonates for recurrent pathological fractures. Bone pain was reduced in all bisphosphonate treated patients with a decrease in subsequent fractures. INTERPRETATION & CONCLUSIONS This series of FD patients from north India shows the varying presentations of this rare disease. Medical treatment with bisphosphonates appears to be potentially rewarding.
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Mandal M, Kumar D, Roy R, Sen R, Das P, Chatterjee M, Jaisankar P. Regioselective one pot synthesis of 3,3′-diindolylethylene derivatives and study of their cytotoxic activity. Bioorg Med Chem Lett 2011; 21:3084-7. [DOI: 10.1016/j.bmcl.2011.03.028] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2010] [Revised: 02/12/2011] [Accepted: 03/09/2011] [Indexed: 11/17/2022]
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Das B, Chowdhury C, Kumar D, Sen R, Roy R, Das P, Chatterjee M. Synthesis, cytotoxicity, and structure–activity relationship (SAR) studies of andrographolide analogues as anti-cancer agent. Bioorg Med Chem Lett 2010; 20:6947-50. [DOI: 10.1016/j.bmcl.2010.09.126] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2010] [Revised: 09/15/2010] [Accepted: 09/27/2010] [Indexed: 01/22/2023]
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Saha P, Sen R, Hariharan C, Kumar D, Das P, Chatterjee M. Berberine chloride causes a caspase-independent, apoptotic-like death in Leishmania donovani promastigotes. Free Radic Res 2010; 43:1101-10. [PMID: 19669998 DOI: 10.1080/10715760903186124] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Berberine chloride, a quarternary isoquinoline alkaloid, is a promising anti-leishmanial compound, IC(50) being 7.1 microM in L. donovani promastigotes. This leishmanicidal activity was initiated by its pro-oxidant effect, evidenced by enhanced generation of reactive oxygen intermediates that was accompanied by depletion of thiols; pre-incubation in N-acetyl cysteine, attenuated its cell viability, corroborating that generation of free radicals triggered its parasiticidal activity. Externalization of phosphatidylserine and elevation of intracellular calcium preceded depolarization of the mitochondrial membrane potential, which translated into an increase in the sub G(0)/G(1) population and was accompanied by DNA laddering, hallmarks of apoptosis. Berberine chloride failed to induce caspase activity and anti-leishmanial activity in the presence of a pan caspase inhibitor, Z-Val-Ala-DL-Asp (methoxy)-fluoromethylketone remained unchanged, which indicated that the apoptosis was caspase independent. Collectively, the data indicates that Berberine chloride triggers an apoptosis-like death following enhanced generation of reactive oxygen species, thus meriting further pharmacological investigations.
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Guha P, Dey A, Sen R, Chatterjee M, Chattopadhyay S, Bandyopadhyay SK. Intracellular GSH depletion triggered mitochondrial Bax translocation to accomplish resveratrol-induced apoptosis in the U937 cell line. J Pharmacol Exp Ther 2010; 336:206-14. [PMID: 20876229 DOI: 10.1124/jpet.110.171983] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
We have previously demonstrated that resveratrol (Resv)-induced cellular apoptosis occurs after formation of reactive oxygen species (ROS) but the role of GSH has not been well defined. Our experimental data enumerated that Resv treatment (50 μm) induced apoptosis in human leukemic monocyte lymphoma cells, which was preceded by cellular GSH efflux. High concentration of extracellular thiol (GSH, N-acetyl cysteine) and two specific inhibitors of carrier-mediated GSH extrusion, methionine or cystathionine, prevented the process of oxidative burst and cell death. This proved that GSH efflux could be a major molecular switch to modulate Resv-induced ROS generation. Spectrofluorometric data depicted that after 6 h of Resv treatment, ROS generation was evident. Pretreatment of cells with intracellular ROS scavenger (polyethylene glycol-superoxide dismutase and polyethylene glycol-catalase) efficiently reduced ROS generation but failed to prevent intracellular GSH depletion. Thus, it suggested that intracellular GSH depletion was independent of ROS production but dependent on GSH extrusion. Furthermore, to bridge the link between GSH efflux and ROS generation, we carried out confocal microscopy of the localization of Bax protein. Microscopic analysis and small interfering RNA treatment emphasized that cellular GSH efflux triggered Bax translocation to mitochondria, which resulted in the loss of mitochondrial membrane potential, ROS generation, and caspase 3 activation and thus triggered apoptosis.
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Sen R, Saha P, Sarkar A, Ganguly S, Chatterjee M. Iron enhances generation of free radicals by Artemisinin causing a caspase-independent, apoptotic death inLeishmania donovanipromastigotes. Free Radic Res 2010; 44:1289-95. [DOI: 10.3109/10715762.2010.498475] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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Sen J, Agarwal S, Singh S, Sen R, Goel S. Benign vs malignant soft tissue neoplasms: limitations of magnetic resonance imaging. Indian J Cancer 2010; 47:280-6. [PMID: 20587903 DOI: 10.4103/0019-509x.64725] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AIMS Various features have been described in the literature to differentiate benign from malignant lesions. The aim of the present study was to study the accuracy of each of these features and that of magnetic resonance imaging (MRI) in diagnosing malignant lesions. MATERIALS AND METHODS Fifty-five consecutive patients presenting with neoplastic (both benign and malignant) lesions diagnosed clinically and on ultrasound were studied and their MRI features were compared with the findings on surgical exploration and histopathologic examination. RESULTS There were 32 (58%) benign and 23 (42%) malignant masses. Malignant masses were more common in patients older than 20 years (83%), and these had symptoms of less than 6 months duration (75%), as against benign lesions. The swelling was painful in 8 malignant masses and these were more common in the upper limbs (61%). Various features of malignant lesions were size more than 5 cm in 83%, change in signal intensity from homogenous on T1-weighted images to heterogenous on T2-weighted images in 74%, irregular margins in 74%, and heterogenous contrast enhancement in 91%. The accuracy of these features was 76%, 58%, 78%, and 60%, respectively. Most benign and malignant lesions were intramuscular in location. A significant number (38%) of benign lesions were located in the intermuscular facial plane. Definitive diagnosis was made in 42% of the lesions. CONCLUSIONS MRI is an excellent modality for evaluating soft tissue neoplasms; however, prediction of a specific diagnosis and differentiation of malignant and benign lesions is not always possible.
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Guha P, Dey A, Dhyani MV, Sen R, Chatterjee M, Chattopadhyay S, Bandyopadhyay SK. Calpain and Caspase Orchestrated Death Signal to Accomplish Apoptosis Induced by Resveratrol and Its Novel Analog Hydroxstilbene-1 in Cancer Cells. J Pharmacol Exp Ther 2010; 334:381-94. [DOI: 10.1124/jpet.110.167668] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
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Sen R, Ganguly S, Saha P, Chatterjee M. Efficacy of artemisinin in experimental visceral leishmaniasis. Int J Antimicrob Agents 2010; 36:43-9. [PMID: 20403680 DOI: 10.1016/j.ijantimicag.2010.03.008] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2009] [Revised: 02/05/2010] [Accepted: 03/03/2010] [Indexed: 10/19/2022]
Abstract
Visceral leishmaniasis (VL), caused by the protozoan Leishmania sp., affects 500000 people annually, with the Indian subcontinent contributing a significant proportion of these cases. Emerging refractoriness to conventional antimony therapy has emphasised the need for safer yet effective antileishmanial drugs. Artemisinin, a widely used antimalarial, demonstrated anti-promastigote activity and the 50% inhibitory concentration (IC(50)) ranged from 100 microM to 120 microM irrespective of Leishmania species studied. Leishmania donovani-infected macrophages demonstrated decreased production of nitrite as well as mRNA expression of inducible nitric oxide synthase, which was normalised by artemisinin, indicating that it exerted both a direct parasiticidal activity as well as inducing a host protective response. Furthermore, in a BALB/c model of VL, orally administered artemisinin (10mg/kg and 25mg/kg body weight) effectively reduced both splenic weight and parasite burden, which was accompanied by a restoration of Th1 cytokines (interferon-gamma and interleukin-2). Taken together, these findings have delineated the therapeutic potential of artemisinin in experimental VL.
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Sen R, Gadagkar R. Natural history and behaviour of the primitively eusocial waspRopalidia marginata(Hymenoptera: Vespidae): a comparison of the two sexes. J NAT HIST 2010. [DOI: 10.1080/00222931003615703] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Mukherjee S, Das P, Sivapathasekaran C, Sen R. Antimicrobial biosurfactants from marineBacillus circulans: extracellular synthesis and purification. Lett Appl Microbiol 2009; 48:281-8. [DOI: 10.1111/j.1472-765x.2008.02485.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Ghalaut PS, Sen R, Dixit G. Role of granulocyte colony stimulating factor (G-CSF) in chemotherapy induced neutropenia. THE JOURNAL OF THE ASSOCIATION OF PHYSICIANS OF INDIA 2008; 56:942-944. [PMID: 19322972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
BACKGROUND In the past decade, there have been many clinical trials investigating the potential benefits of adjunctive therapy with colony stimulating factors (CSFs) both to ameliorate or prevent profound neutropenia and its potentially life threatening consequences. Neutropenia is the most common dose limiting side effects of cytotoxic chemotherapy. We decided to study the effect of same in our patients coming to haematology clinic. AIMS AND OBJECTIVES To see the effect of G-CSF on severity of neutropenia following chemotherapy in patients of haematological malignancies and to see the effect of G-CSF on duration of hospitalization, documented infections and duration of fever as compared to control group in patients with neutropenia following chemotherapy in haematological malignancies. MATERIAL AND METHODS Thirty patients of acute leukemia were prospectively studied. Patients were given G-CSF 24.hours following chemotherapy induced neutropenia and following parameters were observed. (a) median time to ANC recovery (b) incidence and duration of fever (c) duration of hospitalization following chemotherapy (d) incidence of documented infections. The patients were given G-CSF until the neutrophil count was >1000/ml for 3 days or maximum of 7 days. RESULTS Mean age was 29.33 +/- 14 years in G-CSF group and 27.53 +/- 13.75 in control group. Mean duration of neutropenia was 11.4 days (p < 0.05) in G-CSF group and 15.8 days in control group. Mean duration of fever was 8.2 days in G-CSF group and 13.53 days in control group (p < 0.05). Mean duration of hospital stay was 21.33 days in G-CSF group and 25 days in control group (p > 0.05). CONCLUSIONS The study demonstrates that G-CSF administration is efficacious in chemotherapy induced neutropenia by decreasing the duration of neutropenia and duration of fever.
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Sen R, Pratap A, Agrawal A, Adhikary S, Pandey SR. Isolated accessory limb of lower eyelid with multiple dermal appendages. Singapore Med J 2008; 49:e93-e95. [PMID: 18418514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
We report the first case in the English literature of an isolated occurrence of accessory limb with multiple dermal appendages in a ten-month-old boy. This condition presented at birth as a limb bud below the left eyelid, multiple dermal appendages in the adjacent part of the face below the left orbit and on the upper part of the face. No anomalies of the ocular structures or central nervous system were identified. Accessory limb with multiple dermal appendages, in the absence of a congenital cystic eye, is an extremely rare condition representing a benign aberration in the developing musculoskeletal system. We present the first of such a case and endeavour to explain the embryological basis behind it.
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Sarkar A, Sen R, Saha P, Ganguly S, Mandal G, Chatterjee M. An ethanolic extract of leaves of Piper betle (Paan) Linn mediates its antileishmanial activity via apoptosis. Parasitol Res 2008; 102:1249-55. [PMID: 18273645 DOI: 10.1007/s00436-008-0902-y] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2007] [Accepted: 01/22/2008] [Indexed: 10/22/2022]
Abstract
An unprecedented increase in the incidence of unresponsiveness to antimonial compounds has highlighted the urgent need to develop new antileishmanial agents. The leaves of Piper betle (locally known as Paan) have long been in use in the Indian indigenous system of medicine for its antimicrobial properties but its antileishmanial potential has not been studied. Accordingly, an ethanolic extract of leaves of Piper betle (PB) was tested for its antileishmanial activity that was evidenced in both promastigotes and amastigotes, with IC50 values of 9.8 and 5.45 microg/ml, respectively; importantly, it was accompanied by a safety index of >12-fold. This leishmanicidal activity of PB was mediated via apoptosis as evidenced by morphological changes, loss of mitochondrial membrane potential, in situ labeling of DNA fragments by terminal deoxyribonucleotidyltransferase-mediated deoxyuridine triphosphate nick end labeling, and cell-cycle arrest at the sub-G0/G1 phase. Taken together, the data indicate that PB has promising antileishmanial activity that is mediated via programmed cell death and, accordingly, merits consideration and further investigation as a therapeutic option for the treatment of leishmaniasis.
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Das P, Mukherjee S, Sen R. Antimicrobial potential of a lipopeptide biosurfactant derived from a marine Bacillus circulans. J Appl Microbiol 2008; 104:1675-84. [PMID: 18194244 DOI: 10.1111/j.1365-2672.2007.03701.x] [Citation(s) in RCA: 183] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
AIMS To isolate the biologically active fraction of the lipopeptide biosurfactant produced by a marine Bacillus circulans and study its antimicrobial potentials. METHODS AND RESULTS The marine isolate B. circulans was cultivated in glucose mineral salts medium and the crude biosurfactant was isolated by chemical isolation method. The crude biosurfactants were solvent extracted with methanol and the methanol extract was subjected to reverse phase high-performance liquid chromatography (HPLC). The crude biosurfactants resolved into six major fractions in HPLC. The sixth HPLC fraction eluting at a retention time of 27.3 min showed the maximum surface tension-reducing property and reduced the surface tension of water from 72 mNm(-1) to 28 mNm(-1). Only this fraction was found to posses bioactivity and showed a pronounced antimicrobial action against a panel of Gram-positive and Gram-negative pathogenic and semi-pathogenic micro-organisms including a few multidrug-resistant (MDR) pathogenic clinical isolates. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of this antimicrobial fraction of the biosurfactant were determined for these test organisms. The biosurfactant was found to be active against Gram-negative bacteria such as Proteus vulgaris and Alcaligens faecalis at a concentration as low as 10 microg ml(-1). The biosurfactant was also active against methicillin-resistant Staphylococcus aureus (MRSA) and other MDR pathogenic strains. The chemical identity of this bioactive biosurfactant fraction was determined by post chromatographic detection using thin layer chromatography (TLC) and also by Fourier transform infrared (FTIR) spectroscopy. The antimicrobial HPLC fraction resolved as a single spot on TLC and showed positive reaction with ninhydrin, iodine and rhodamine-B reagents, indicating its lipopeptide nature. IR absorption by this fraction also showed similar and overlapping patterns with that of other lipopeptide biosurfactants such as surfactin and lichenysin, proving this biosurfactant fraction to be a lipopeptide. The biosurfactant did not show any haemolytic activity when tested on blood agar plates, unlike the lipopeptide biosurfactant surfactin produced by Bacillus subtilis. CONCLUSIONS The biosurfactant produced by marine B. circulans had a potent antimicrobial activity against Gram-positive and Gram-negative pathogenic and semi-pathogenic microbial strains including MDR strains. Only one of the HPLC fractions of the crude biosurfactants was responsible for its antimicrobial action. The antimicrobial lipopeptide biosurfactant fraction was also found to be nonhaemolytic in nature. SIGNIFICANCE AND IMPACT OF THE STUDY This work presents a nonhaemolytic lipopeptide biosurfactant produced by a marine micro-organism possessing a pronounced antimicrobial action against a wide range of bacteria. There is a high demand for new antimicrobial agents because of the increased resistance shown by pathogenic micro-organisms against the existing antimicrobial drugs. This study provides an insight into the search of new bioactive molecules from marine micro-organisms.
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Sen R, Bandyopadhyay S, Dutta A, Mandal G, Ganguly S, Saha P, Chatterjee M. Artemisinin triggers induction of cell-cycle arrest and apoptosis in Leishmania donovani promastigotes. J Med Microbiol 2007; 56:1213-1218. [PMID: 17761485 DOI: 10.1099/jmm.0.47364-0] [Citation(s) in RCA: 147] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
A major impediment to effective anti-leishmanial chemotherapy is the emergence of drug resistance, especially to sodium antimony gluconate, the first-line treatment for leishmaniasis. Artemisinin, a sesquiterpene lactone isolated from Artemisia annua, is an established anti-malarial compound that showed anti-leishmanial activity in both promastigotes and amastigotes, with IC(50) values of 160 and 22 microM, respectively, and, importantly, was accompanied by a high safety index (>22-fold). The leishmanicidal activity of artemisinin was mediated via apoptosis as evidenced by externalization of phosphatidylserine, loss of mitochondrial membrane potential, in situ labelling of DNA fragments by terminal deoxyribonucleotidyltransferase-mediated dUTP nick end labelling (TUNEL) and cell-cycle arrest at the sub-G(0)/G(1) phase. Taken together, these data indicate that artemisinin has promising anti-leishmanial activity that is mediated by programmed cell death and, accordingly, merits consideration and further investigation as a therapeutic option for the treatment of leishmaniasis.
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Sen R, Bauri AK, Chattopadhyay S, Chatterjee M. Antipromastigote activity of the malabaricones ofMyristica malabarica (rampatri). Phytother Res 2007; 21:592-5. [PMID: 17335115 DOI: 10.1002/ptr.2115] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
A major problem in the management of visceral leishmaniasis, especially in the Indian subcontinent, is the growing unresponsiveness to conventional antimonial therapy, indicating the urgent need to identify new antileishmanial compounds. This study was undertaken to evaluate the antileishmanial activity of the fruit rind of Myristica malabarica that is used as a spice and is also credited with medicinal properties. The antipromastigote activity of different extracts/fractions of M. malabarica and its constituent diarylnonanoids were evaluated in Leishmania donovani promastigotes (MHOM/IN/83/AG83) using the MTS-PMS assay. Preliminary screening of the ether extract (R1) with its crude methanol fraction (R2) and two fractions (R3 and R4) revealed that R2 had potent leishmanicidal activity (IC(50) 31.0 microg/mL), whereas R3 and R4 showed poor activity. Fractionation of R2 yielded four diarylnonanoids (malabaricones A-D, designated as Mal A, Mal B, Mal C and Mal D, respectively). The IC(50) values of Mal A-D were 16, 22, 27 and >50 microg/mL, respectively. Taken together, the data suggest that the methanol extract of M. malabarica, especially its constituent compounds, Mal A and Mal B, have promising antileishmanial activity meriting further investigations regarding the underlying molecular mechanism(s) of action with a view towards future drug development.
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Singh R, Sharma AK, Magu NK, Kaur KP, Sen R, Magu S. Extraskeletal osteochondroma in the nape of the neck: a case report. J Orthop Surg (Hong Kong) 2006; 14:192-5. [PMID: 16914787 DOI: 10.1177/230949900601400217] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Extraskeletal osteochondroma in the nape of the neck is rare and its pathological diagnosis is based on radiological and histopathological examination. It is vital that such a diagnosis be considered when a discrete, ossified mass is localised in soft tissues, even at atypical sites. Differential diagnoses include myositis ossificans, a lipomatous lesion, a pseudomalignant osseous tumour, an ossifying fibromyxoid tumour, an extraskeletal chondroma with endochondral ossification, synovial (osteo) chondromatosis, tumoural calcinosis, a synovial sarcoma, and an extraskeletal osteosarcoma. Clinical awareness of this benign entity is important as no malignant transformation or metastasis has been reported. Marginal excision with histopathological identification is the treatment of choice.
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Teoh B, Lyons S, Sen R, Abbott J. 154. J Minim Invasive Gynecol 2005. [DOI: 10.1016/j.jmig.2005.07.153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Bradford NM, Sen R. Engineering Judgment and the Design That Got Away. JOURNAL OF PROFESSIONAL ISSUES IN ENGINEERING EDUCATION AND PRACTICE 2004. [DOI: 10.1061/(asce)1052-3928(2004)130:2(84)] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
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Sen R, Singh S, Singh H, Gupta A, Sen J. Clinical profile in gelatinous bone marrow transformation. THE JOURNAL OF THE ASSOCIATION OF PHYSICIANS OF INDIA 2003; 51:585-8. [PMID: 15266925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/30/2023]
Abstract
OBJECTIVE To study the clinical spectrum associated with gelatinous bone marrow transformation (GMT). METHODS All subjects whose bone marrow aspiration showed pink purple material on Leishman stain underwent a detail history, clinical examination and investigation (biochemical/microbiological/radiological). Additionally, in each subject the smear was stained with special stains of Periodic Acid Schiff and Alcian blue. RESULTS Out of total 1498 marrows, 65 showed evidence of GMT. All of these had anaemia. The associated clinical spectra of diseases noticed were: Infection (31 cases), Nutritional deficiency (5 cases), Haematological disorders (Aplastic/toxic depression) (17 cases), Malignancies (3 cases), and Miscellaneous (9 cases). CONCLUSION Based on the heterogenecity of associated clinical disorders, GMT indicates severe illness and not a particular disease. GMT may be a result of bioregulatory process (which presently needs further prospective studies) that are activated in different pathologic conditions but resulting in similar lesion in the bone marrow and so till then it may be concluded that GMT is a symptom of bone marrow.
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