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Anand JJS, Kumaran V, Rajamani G, Kannan S, Mohan NV, Rengarajan R, Muthulingam V. Route to neo-inguinal canal: Our experience. J Minim Access Surg 2011; 7:178-80. [PMID: 22022100 PMCID: PMC3193758 DOI: 10.4103/0972-9941.83509] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2009] [Accepted: 04/15/2010] [Indexed: 11/04/2022] Open
Abstract
AIM The objective of this study was to stress the importance and value of this route to neo-inguinal canal creation for undescended testis management laparoscopically. MATERIALS AND METHODS Data from the Department of Paediatric Surgery, Coimbatore Medical College, was taken. Retrospective study was undertaken for the period 2004 to 2008. Here the surgical technique and outcome of the treatment are recorded for children aged 1 year to 12 years. RESULTS A total of 126 children underwent laparoscopic stage II surgery by this route (medial to the medial umbilical ligament). Right-sided undescended testis (UDT) was present in 76 (60%) patients. Left-sided UDT was present in 45 (35%) patients. Bilateral UDT was present in 5 (5%) patients. There were 90 (71%) patients aged less than 2 years and 36 (29%) patients aged more than 2 years. The eldest patient was 12 years of age. The overall hospital stay was 1 day. There were no complications seen in the follow-up. In all cases, the testis could not be brought down in a single stage. CONCLUSION Creation of neo-inguinal canal medial to the medial umbilical ligament and just lateral to the bladder has the advantage of gaining more length on the vessels and vas to bring the testis to scrotum. The laparoscopic management of undescended testis in stage II by this innovative new route is simple, less complicated and well tolerated.
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Sharma SD, Kumar S, Dagaonkar SS, Bisht G, Dayanand S, Devi R, Deshpande SS, Chaudhary S, Bhatt BC, Kannan S. Dosimetric comparison of linear accelerator-based stereotactic radiosurgery systems. J Med Phys 2011; 32:18-23. [PMID: 21217914 PMCID: PMC3003883 DOI: 10.4103/0971-6203.31145] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2006] [Accepted: 12/04/2006] [Indexed: 11/04/2022] Open
Abstract
Stereotactic radiosurgery (SRS) is a special radiotherapy technique used to irradiate intracranial lesions by 3-D arrangements of narrow photon beams eliminating the needs of invasive surgery. Three different tertiary collimators, namely BrainLab and Radionics circular cones and BrainLab micro multileaf collimator (mMLC), are used for linear accelerator-based SRS systems (X-Knife). Output factor (S(t)), tissue maximum ratio (TMR) and off axis ratio (OAR) of these three SRS systems were measured using CC01 (Scanditronix/ Welhofer) and Pinpoint (PTW) cylindrical and Markus plane parallel ionization chambers as well as TLD and radiochromic film. Measurement results of CC01 and Pinpoint chambers were very close to each other which indicate that further reduction in volume and physical dimensions of cylindrical ionization chamber is not necessary for SRS/SRT dosimetry. Output factors of BrainLab and Radionics SRS cones were very close to each other while output factors of equivalent diameter mMLC field were different from SRS circular cones. TMR of the three SRS systems compared were very close to one another. OAR of Radionics cone and BrainLab mMLC were very close to each other, within 2%. However, OARs of BrainLab cone were found comparable to OARs of Radionics cone and BrainLab mMLC within maximum variation of 4%. In addition, user-measured similar data of other three mMLC X-Knives were compared with the mMLC X-Knife data measured in this work and found comparable. The concept of switching over to mMLC-based SRS/SRT is thus validated from dosimetric characteristics as well.
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Bhandary KS, Kumaran V, Rajamani G, Kannan S, Mohan NV, Rangarajan R, Muthulingam V. Laparoscopic assisted anorectal pull through: Reformed techniques. J Indian Assoc Pediatr Surg 2011; 14:210-4. [PMID: 20419023 PMCID: PMC2858884 DOI: 10.4103/0971-9261.59604] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
AIM To assess the modifications in the technique of laparoscopic assisted anorectal pull through (LAARP) practiced at our institute and analyze the post operative outcome and associated complications. MATERIALS AND METHODS A retrospective study from January 2001 to May 2009 analyzing LAARP for high anorectal malformations. RESULTS A total of 40 patients - 34 males and six females, in the age group of two months to six years were studied. Staged procedure was done in 39 patients; one child with recto vestibular fistula underwent single stage procedure. All the patients withstood surgery well. One patient required conversion due to problems in gaining enough length for the distal rectum in a patient with rectovesical fistula so colostomy was closed and re-located at a proximal splenic flexure. The complications were mucosal prolapse (six cases), anal stenosis (three), adhesive obstruction (two), distal rectal necrosis (one), and urethral diverticulum (one). The patients were followed up with clinical evaluation and continence scoring. The progress has been satisfactory and weight-gain is adequate. CONCLUSIONS THE ADVANTAGES OF THE REFORMED TECHNIQUES ARE AS FOLLOWS: Transcutaneous bladder stitch provides excellent visualization; traction over the fistula helps in dissection of the puborectalis, dividing the fistula without ligation is safe, railroading of Hegar's dilators over the suction canula creates adequate pull through channel, saves time and makes procedure simpler with reproducible comparable reports.
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Wahlstrand JK, Zhang H, Choi SB, Kannan S, Dessau DS, Sipe JE, Cundiff ST. Optical coherent control induced by an electric field in a semiconductor: a new manifestation of the Franz-Keldysh effect. PHYSICAL REVIEW LETTERS 2011; 106:247404. [PMID: 21770599 DOI: 10.1103/physrevlett.106.247404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2010] [Revised: 04/05/2011] [Indexed: 05/31/2023]
Abstract
In (100)-oriented GaAs illuminated at normal incidence by a laser and its second harmonic, interference between one- and two-photon absorption results in ballistic current injection, but not modulation of the overall carrier injection rate. Results from a pump-probe experiment on a transversely biased sample show that a constant electric field enables coherent control of the carrier injection rate. We ascribe this to the nonlinear optical Franz-Keldysh effect and calculate it for a two-band parabolic model. The mechanism is relevant to centrosymmetric semiconductors as well.
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Thippeswamy R, Mathew L, Bhosale B, Kumar N, Kannan S, Joshi A, Rangarajan V, Khattry N. LACE: A conditioning regimen for patients with lymphoma undergoing autologous transplant. J Clin Oncol 2011. [DOI: 10.1200/jco.2011.29.15_suppl.6591] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Gupta T, Master Z, Kannan S, Agarwal J, Ghosh-Laskar S, Rangarajan V. 133 oral DIAGNOSTIC PERFORMANCE OF FDG-PET(CT) FOR POST-TREATMENT RESTAGING OF HEAD-NECK CANCERS: A META-ANALYSIS. Radiother Oncol 2011. [DOI: 10.1016/s0167-8140(11)70255-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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207
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Kannan S, Dvonch JT, Schulz AJ, Israel BA, Mentz G, House J, Max P, Reyes AG. Exposure to fine particulate matter and acute effects on blood pressure: effect modification by measures of obesity and location. J Epidemiol Community Health 2011; 64:68-74. [PMID: 19833604 DOI: 10.1136/jech.2008.081836] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND Observational studies and controlled experiments have provided evidence that airborne particulate matter (PM) is capable of acutely increasing blood pressure (BP) in certain scenarios. The goal of this study was to evaluate whether and to what extent obesity and community location affect relationships between fine particulate matter (PM(2.5)) and blood pressure (BP) measures. METHODS Using data from a stratified random sample survey of adults conducted in 2002-3 in Detroit, Michigan, we tested body mass index (BMI) and waist circumference (WCIR) in separate models as effect modifiers of the relationship between PM(2.5) exposure and BP. We also tested interactions with community location. Models were adjusted for covariates with established pro-hypertensive effects. RESULTS PM(2.5) exposure was positively associated with increased pulse pressure (PP) for those categorised as obese (BMI> or =30) across lags 2 (beta 4.16, p<0.05) and 3 days (beta 2.55, p<0.05) prior to BP measure. WCIR similarly modified the effect of exposure to PM(2.5) on PP (beta 4.34, p<0.003). The observed effects were enhanced in the community with closer proximity to local emissions of PM(2.5), and for residents classified as obese (BMI> or =30) or with WCIR above high-risk cuts points. CONCLUSIONS This community-based study suggests that positive associations between PM(2.5) exposure and PP and systolic BP are enhanced in areas proximate to sources of PM (2.5) emissions. These patterns were observed for all residents, but were more visible and consistent among those who were obese. Research is needed to examine the mechanistic pathways by which air particles interact with obesity and location to affect BP, and inform community interventions to reduce the population burden of hypertension and related co-morbidities.
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Samar Ali S, Kannan S. A diagnostic approach to Weibull‐Weibull stress‐strength model and its generalization. INTERNATIONAL JOURNAL OF QUALITY & RELIABILITY MANAGEMENT 2011. [DOI: 10.1108/02656711111121834] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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209
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Kannan S, Vieira SI, Olhero SM, Torres PMC, Pina S, da Cruz e Silva OAB, Ferreira JMF. Synthesis, mechanical and biological characterization of ionic doped carbonated hydroxyapatite/β-tricalcium phosphate mixtures. Acta Biomater 2011; 7:1835-43. [PMID: 21146640 DOI: 10.1016/j.actbio.2010.12.009] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2010] [Revised: 12/02/2010] [Accepted: 12/06/2010] [Indexed: 11/17/2022]
Abstract
The influence of ionic substituents in calcium phosphates intended for bone and tooth replacement biomedical applications is an important research topic, owing to the essential roles played by trace elements in biological processes. The present study investigates the mechanical and biological evaluation of ionic doped hydroxyapatite/β-tricalcium phosphate mixtures which have been prepared by a simple aqueous precipitation method. Heat treating the resultant calcium phosphates in a carbonated atmosphere led to the formation of ionic doped carbonated hydroxyapatite/β-tricalcium phosphate mixtures containing the essential ions of biological apatite. The structural analysis determined by Rietveld refinement confirmed the presence of hydroxyapatite as the main phase, together with a considerable amount of β-tricalcium phosphate. Such phase assemblage is essentially due to the influence of substituted ions during synthesis. The results from mechanical tests proved that carbonate substitutions are detrimental for the mechanical properties of apatite-based ceramics. In vitro proliferation assays of osteoblastic-like cells (MC3T3-E1 cell line) to powders revealed that carbonate incorporation can either delay or accelerate MC3T3 proliferation, although reaching the same proliferation levels as control cells after 2 weeks in culture. Further, the powders enable pre-osteoblastic differentiation in a similar manner to control cells, as indirectly measured by ALP activity and Type-I collagen medium secretion.
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Sailasree R, Nalinakumari KR, Sebastian P, Kannan S. Influence of methylenetetrahydrofolate reductase polymorphisms in oral cancer patients. J Oral Pathol Med 2010; 40:61-6. [PMID: 20923444 DOI: 10.1111/j.1600-0714.2010.00943.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
BACKGROUND Methylenetetrahydrofolate reductase (MTHFR) is a key enzyme in folate metabolism. Two common polymorphisms associated with MTHFR gene - C677T and A1298C - influence the thermolabile nature and activity of the enzyme. This study aimed to investigate the role of MTHFR polymorphisms on oral cancer susceptibility and its potential impact on the prognostic outcome. METHODS Oral cancer cases and controls were genotyped using PCR-RFLP technique for MTHFR C677T and A1298C polymorphisms. Disease susceptibility analysed using regression analysis. The association between clinical outcomes and the polymorphisms were analysed using univariate and multivariate model. RESULTS The 677CT+TT genotype showed a significant three-fold reduction in oral cancer risk (RR-0.35, p-0.009). 1298CC genotype showed decreased cancer risk when compared to AA+AC genotype (RR-0.55, p-0.062). When prognostic significance of MTHFR polymorphism was evaluated, 677CT+TT patients showed improved survival than the CC individuals (RR = 0.56, P = 0.378). The 1298 CC and AC+CC showed an increased risk for treatment failure and poor survival when compared with the wild AA genotype (HR = 4.27, P = 0.001). CONCLUSION Here we observed MTHFR C677T to influence oral cancer susceptibility, while A1298C polymorphism associated with patient prognosis. Our data support MTHFR polymorphism to be an independent prognostic marker in oral carcinoma.
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Gopi D, Indira J, Kavitha L, Kannan S, Ferreira JMF. Spectroscopic characterization of nanohydroxyapatite synthesized by molten salt method. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2010; 77:545-547. [PMID: 20609618 DOI: 10.1016/j.saa.2010.06.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2009] [Revised: 05/05/2010] [Accepted: 06/07/2010] [Indexed: 05/29/2023]
Abstract
Hydroxyapatite (HAP) nanopowders were synthesized by molten salt method at 260 degrees C. The as-prepared powders were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscope (SEM) and thermo gravimetric analysis (TGA). With the aid of the obtained results the effect of calcining time on the crystallinity, size and morphology of HAP nanopowders is presented. The HAP nanopowders synthesized by molten salt method consist of pure phase of HAP without any impurities and showed the rod-like morphology without detectable decomposition up to 1100 degrees C.
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Deb S, Kannan S, Drew M. Synthesis and structural studies of a bis(carbamoyl methyl) sulfoxide complex of uranyl nitrate. J COORD CHEM 2010. [DOI: 10.1080/00958972.2010.517269] [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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213
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Kannan S, Chandran GJ, Pillai KR, Mathew B, Sujathan K, Nalinakumary KR, Nair MK. Expression of p53 in leukoplakia and squamous cell carcinoma of the oral mucosa: correlation with expression of Ki67. Mol Pathol 2010; 49:M170-5. [PMID: 16696067 PMCID: PMC408045 DOI: 10.1136/mp.49.3.m170] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Aim-To study p53 expression in relation to proliferative status in normal and nondysplastic, dysplastic and malignant lesions of the oral mucosa.Method-The standard avidin-biotin complex (ABC) immunohistochemical staining method was used to study the expression of p53 and Ki67 on frozen sections of oral leukoplakias and carcinomas.Results-Of the leukoplakia and carcinoma samples, 70% expressed p53 in over 5% of cells. In normal mucosa less than 5% of cells expressed p53. The proliferation index, as assessed by expression of Ki67, was highest in the malignant lesions (43%) and lowest in normal mucosa (11%). Statistical analysis revealed that expression of both p53 and Ki67 was correlated significantly with the histopathological stage of the tumour. However, expression of p53 was not correlated with that of Ki67. In leukoplakia lesions with proliferative features p53 immunostaining was less intense than in non-proliferative lesions; this difference was statistically significant.Conclusions-These results emphasise the potential of Ki67 and p53 as biomarkers of carcinogenesis in oral cancer and may also serve as intermediate points for cancer prevention programmes, such as the oral chemopreventive trials. Factors other than p53 may have a more important role in the deregulation of proliferation in pre-malignant oral lesions.
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Bhavan PS, Radhakrishnan S, Seenivasan C, Shanthi R, Poongodi R, Kannan S. Proximate Composition and Profiles of Amino Acids and Fatty Acids in the Muscle of Adult Males and Females of Commercially Viable Prawn Species Macrobrachium rosenbergii Collected from Natural Culture Environments. ACTA ACUST UNITED AC 2010. [DOI: 10.5539/ijb.v2n2p107] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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215
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Navath RS, Menjoge AR, Wang B, Romero R, Kannan S, Kannan RM. Amino acid-functionalized dendrimers with heterobifunctional chemoselective peripheral groups for drug delivery applications. Biomacromolecules 2010; 11:1544-63. [PMID: 20415504 PMCID: PMC3589517 DOI: 10.1021/bm100186b] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Dendrimers have emerged as multifunctional carriers for targeted drug delivery, gene delivery and imaging. Improving the functional versatility at the surface for carrying multiple conjugation reactions is becoming vital. Typically, generation four polyamidoamine (G4-PAMAM) dendrimers bear approximately 64 symmetrical end groups, often requiring different spacers to conjugate various functional groups (drugs and targeting moities), increasing the synthetic steps. In the present study, a simple one-step synthesis to convert each symmetrical end group of G4-PAMAM dendrimers into two reactive, distinct orthogonal and chemoselective groups is described. A near-complete end-capping of the dendrimers (87-93%) with amino acids results in heterobifunctional G4-PAMAM dendrimers bearing a very high (> or = 110) diverse peripheral end groups (OH+NHBoc, OH+COOMe, SH+NHBoc, and COOH+NHBoc). Postfunctionalization ability of these dendrimers was evaluated. The heterobifunctional groups at the dendrimer periphery could be chemoselectively conjugated to multiple moities such as drugs (indomethacin and dexamethasone) and drugs and imaging agents (dexamethasone and FITC). These conjugations could be achieved in immediate succession without functional group conversions, eliminating the additional elaborate synthetic steps traditionally required to append specific linkers. Furthermore, one of the two functional handles at periphery was used to develop in situ forming hydrogels, whereas the other handle could be used for conjugating the drugs (e.g., dexamethasone). The heterobifunctional dendrimers with either "NH(2) or SH (thiopyridyl protected form)" terminations showed in situ hydrogel formation by cross-linking with N-hydroxysuccinimide or thiol-terminated multiarm polyethylene glycol (20 kDa). The choice of amino acids as versatile linkers would enable biocompatible dendrimer scaffolds for use in drug delivery. Zeta-potential measurements showed drastic lowering of the charge on G4-PAMAM-NH(2) dendrimers by end-capping with amino acids, whereas in the case of neutral G4-PAMAM-OH dendrimers, the charge did not increase or decrease substantially. The in vitro cytotoxicity and hemolysis assay showed that the heterobifunctional dendrimers were noncytotoxic in the 100 ng/mL to 1 mg/mL concentration range. With this study, we demonstrate the development of biocompatible dendrimers bearing multiple orthogonal surface groups, enabling the attachment of drugs, imaging agents, and gel formation using minimal synthetic steps.
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Kannan S, Deb SB, Drew MG. Synthesis, characterization and molecular structure of 1,1′ bis(diphenylphosphino ferrocene)dioxide complex of uranyl nitrate. Inorganica Chim Acta 2010. [DOI: 10.1016/j.ica.2010.03.032] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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217
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Antonyraj CA, Gandhi M, Kannan S. Phenol Hydroxylation over Cu-Containing LDHs and Their Calcined Forms: Profound Cobivalent Metal Influence. Ind Eng Chem Res 2010. [DOI: 10.1021/ie100399j] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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218
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Singh R, Joshi A, Bagal B, Kannan S, Banavali S, Nair R, Khattry N. Long-term outcome of pediatric allogenic transplantation from Tata Memorial Centre, Mumbai. J Clin Oncol 2010. [DOI: 10.1200/jco.2010.28.15_suppl.e17000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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219
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Prabhash K, Khattry N, Alai V, Joshi A, Bakshi AV, Kannan S, Sastry P, Parikh PM, Kode J. CD26 expression in donor stem cell harvest and its correlation with engraftment in human haematopoietic stem cell transplantation: Potential predictor of early engraftment. J Clin Oncol 2010. [DOI: 10.1200/jco.2010.28.15_suppl.6544] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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220
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Prabhash K, Khattry N, Bakshi A, Karandikar R, Joshi A, Kannan S, Sastry PSRK, Parikh P, Kode JA. CD26 expression in donor stem cell harvest and its correlation with engraftment in human haematopoietic stem cell transplantation: potential predictor of early engraftment. Ann Oncol 2010; 21:582-588. [PMID: 19759183 DOI: 10.1093/annonc/mdp342] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND The efficiency of haematopoietic stem and progenitor cells (HSPCs) is important when donor cell numbers are limiting. Stable white blood cell (WBC) and platelet engraftment is crucial for the outcome of haematopoietic stem cell transplantation (HSCT). DESIGN This article evaluates CD26/dipeptidyl peptidase-IV expression on mobilised peripheral blood stem cell (PBSC) harvest of donors and its correlation with engraftment in HSCT. We have analysed CD26 expression on cells in various gates, that is, lymphocytes, monocytes, neutrophils and all populations using flow cytometry tool. RESULTS Ours is the first study on human mobilised PBSC harvest from cancer patients or allogeneic related donors (n = 28) to demonstrate that increased CD26 expression leads to early engraftment in transplanted cancer patients. Correlation of CD26 expression with WBC engraftment was statistically significant (lymphocyte gate: P < 0.00001; monocyte gate: P < 0.00001; neutrophil gate: P < 0.00001; all populations: P < 0.00001). CD34 expression is a known predictor of engraftment. Nevertheless, there was no correlation between CD34 and CD26 expression in these cases. CONCLUSIONS This study has given important leads indicating that CD26 expression may be an independent predictor of engraftment. Further study with large number of patients as well as study on circulatory CD26 may add valuable information towards improving current knowledge on CD26.
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Kannan S, Goetz-Neunhoeffer F, Neubauer J, Pina S, Torres P, Ferreira J. Synthesis and structural characterization of strontium- and magnesium-co-substituted beta-tricalcium phosphate. Acta Biomater 2010; 6:571-6. [PMID: 19679202 DOI: 10.1016/j.actbio.2009.08.009] [Citation(s) in RCA: 114] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2009] [Revised: 07/07/2009] [Accepted: 08/03/2009] [Indexed: 11/26/2022]
Abstract
The synthesis of five different Sr(2+)- and Mg(2+)-co-substituted beta-tricalcium phosphate (beta-TCP) has been obtained by heating the calcium-deficient apatites above 800 degrees C. With the investigated concentrations of Sr(2+) and Mg(2+) from the present study, no additional phases other than beta-TCP have been detected. The synthesized powders have been characterized by X-ray diffraction, Fourier transform infrared spectrometry, elemental analysis and Rietveld refinement studies. The co-substitution of Sr(2+) and Mg(2+) in the beta-TCP has resulted in the formation of crystalline beta-TCP at hexagonal setting (space group R3c). The reduction of lattice a- and c-axis parameters with the combined substitution of Sr(2+) and Mg(2+) in the beta-TCP has been found evident from the present results. Sr(2+) has been found occupying the Ca(1,2,3,4) sites and Mg(2+) was found at the sixfold coordinated Ca(5) site of beta-TCP structure.
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Antonyraj CA, Koilraj P, Kannan S. Synthesis of delaminated LDH: A facile two step approach. Chem Commun (Camb) 2010; 46:1902-4. [DOI: 10.1039/b922122k] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
One-step synthesis of carbonate-free nitrate containing LDHs was achieved using hexamine hydrolysis at low temperature and the products were delaminated successfully in water; materials showed total delamination in formamide while restacking behavior depended critically on the medium.
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Gamare JS, Chetty KV, Mukerjee SK, Kannan S. Extraction studies of uranium(VI), plutonium(IV) and americium(III) from nitric acid using the bi-functional carbamoyl methyl sulfoxide ligands. ANAL SCI 2009; 25:1167-70. [PMID: 19745549 DOI: 10.2116/analsci.25.1167] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The extraction behavior of new bi-functional ligands containing sulfoxide and amide groups viz. N,N'-dibutyl carbamoyl methyl phenyl sulfoxide (L1) and N,N'-dibutyl carbamoyl methyl benzyl sulfoxide (L2) towards the U(VI), Pu(IV) and Am(III) ions from nitric acid was studied. Both of these extractants showed appreciable extractions for U(VI) and Pu(IV) from 1 to 9.5 M nitric acid concentrations. Am(III) did not show an appreciable extraction under the conditions studied. The species extracted from a nitric acid medium correspond to the compositions of [UO2(NO3)(2).2L] and [Pu(NO3)4.2L] for L1 and a mixture of [UO2(NO3)(2).2L], [UO2(NO3)2.L] and [Pu(NO3)(4).2L] for the L2. The conditional extraction constant (Kex) values for the Pu(IV) with L1 and L2 were estimated for the first time, and found to be 6.21 x 10(2) and 5.64 x 10(2) mol(-4) dm, respectively.
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Deb S, Gamare J, Kannan S, Drew M. Uranyl(VI) and lanthanum(III) thio-diglycolamides complexes: Synthesis and structural studies involving nitrate complexation. Polyhedron 2009. [DOI: 10.1016/j.poly.2009.06.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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225
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Wang B, Navath RS, Romero R, Kannan S, Kannan R. Anti-inflammatory and anti-oxidant activity of anionic dendrimer-N-acetyl cysteine conjugates in activated microglial cells. Int J Pharm 2009; 377:159-68. [PMID: 19463931 PMCID: PMC3917717 DOI: 10.1016/j.ijpharm.2009.04.050] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2009] [Revised: 04/29/2009] [Accepted: 04/29/2009] [Indexed: 02/06/2023]
Abstract
Dendrimers are emerging as potential intracellular drug delivery vehicles. Understanding and improving the cellular efficacy of dendrimer-drug conjugates, can lead to significant in vivo benefits. This study explores efficacy of anionic polyamidoamine (PAMAM-COOH) dendrimer-N-acetyl cysteine (NAC) conjugates for applications in neuroinflammation. The anti-oxidative and anti-inflammatory effects of PAMAM-(COOH)(46)-(NAC)(18) conjugate is evaluated on microglial cells in vitro. Cell entry and localization of PAMAM-(COOH)(62)-(FITC)(2) conjugate in BV-2 microglial cells were assessed using flow cytometry and confocal microscopy. ELISA assays were used to evaluate markers of oxidative stress (ROS, NO) and inflammation (TNF-alpha) after stimulation of microglial cells with lipopolysaccharides (LPS), following treatment with increasing doses of free N-acetyl-L-cysteine (NAC) or PAMAM-(COOH)(46)-(NAC)(18) conjugate containing an equivalent molar concentration of NAC. Flow cytometry and confocal microscopy demonstrated the PAMAM-(COOH)(62)-(FITC)(2) conjugate entered BV-2 cells rapidly with significant increase in fluorescence within 15 min and localized mostly in the cytoplasm. PAMAM-(COOH)(46)-(NAC)(18) conjugate was non-toxic, and significantly reduced ROS, NO and TNF-alpha release by activated microglial cells after 24 h and 72 h stimulation of LPS following 3h pre-treatment when compared to the same concentration of free NAC (P<0.05 or P<0.01). Anionic PAMAM dendrimer-NAC conjugate was synthesized with a glutathione sensitive linker for intracellular release. The non-toxic conjugate is a more effective anti-oxidant and anti-inflammatory agent when compared to free NAC in vitro. The conjugate showed significant efficacy even at the lowest dose (0.5mM NAC), where the activity was comparable or better than that of free drug at 8mM (16x higher dosage). The improved efficacy of the conjugate, when combined with the intrinsic neuroinflammation-targeting ability of the PAMAM dendrimers, may provide new opportunities for in vivo applications.
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